NEWS
author wenzelm
Fri, 27 Apr 2012 21:02:34 +0200
changeset 48677 7e009f4e9f47
parent 48615 f98bbb445c06
child 48678 befe55c8bbdc
permissions -rw-r--r--
tuned;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2012 (May 2012)
     5 ------------------------------
     6 
     7 *** General ***
     8 
     9 * Prover IDE (PIDE) improvements:
    10 
    11   - more robust Sledgehammer integration (as before the sledgehammer
    12     command-line needs to be typed into the source buffer)
    13   - markup for bound variables
    14   - markup for types of term variables (displayed as tooltips)
    15   - support for user-defined Isar commands within the running session
    16   - improved support for Unicode outside original 16bit range
    17     e.g. glyph for \<A> (thanks to jEdit 4.5.1)
    18 
    19 * Forward declaration of outer syntax keywords within the theory
    20 header -- minor INCOMPATIBILITY for user-defined commands.  Allow new
    21 commands to be used in the same theory where defined.
    22 
    23 * Rule attributes in local theory declarations (e.g. locale or class)
    24 are now statically evaluated: the resulting theorem is stored instead
    25 of the original expression.  INCOMPATIBILITY in rare situations, where
    26 the historic accident of dynamic re-evaluation in interpretations
    27 etc. was exploited.
    28 
    29 * Commands 'lemmas' and 'theorems' allow local variables using 'for'
    30 declaration, and results are standardized before being stored.  Thus
    31 old-style "standard" after instantiation or composition of facts
    32 becomes obsolete.  Minor INCOMPATIBILITY, due to potential change of
    33 indices of schematic variables.
    34 
    35 * Simplified configuration options for syntax ambiguity: see
    36 "syntax_ambiguity_warning" and "syntax_ambiguity_limit" in isar-ref
    37 manual.  Minor INCOMPATIBILITY.
    38 
    39 * Updated and extended reference manuals: "isar-ref" and
    40 "implementation"; reduced remaining material in old "ref" manual.
    41 
    42 
    43 *** Pure ***
    44 
    45 * Auxiliary contexts indicate block structure for specifications with
    46 additional parameters and assumptions.  Such unnamed contexts may be
    47 nested within other targets, like 'theory', 'locale', 'class',
    48 'instantiation' etc.  Results from the local context are generalized
    49 accordingly and applied to the enclosing target context.  Example:
    50 
    51   context
    52     fixes x y z :: 'a
    53     assumes xy: "x = y" and yz: "y = z"
    54   begin
    55 
    56   lemma my_trans: "x = z" using xy yz by simp
    57 
    58   end
    59 
    60   thm my_trans
    61 
    62 The most basic application is to factor-out context elements of
    63 several fixes/assumes/shows theorem statements, e.g. see
    64 ~~/src/HOL/Isar_Examples/Group_Context.thy
    65 
    66 Any other local theory specification element works within the "context
    67 ... begin ... end" block as well.
    68 
    69 * Bundled declarations associate attributed fact expressions with a
    70 given name in the context.  These may be later included in other
    71 contexts.  This allows to manage context extensions casually, without
    72 the logical dependencies of locales and locale interpretation.
    73 
    74 See commands 'bundle', 'include', 'including' etc. in the isar-ref
    75 manual.
    76 
    77 * Rule composition via attribute "OF" (or ML functions OF/MRS) is more
    78 tolerant against multiple unifiers, as long as the final result is
    79 unique.  (As before, rules are composed in canonical right-to-left
    80 order to accommodate newly introduced premises.)
    81 
    82 * Command 'definition' no longer exports the foundational "raw_def"
    83 into the user context.  Minor INCOMPATIBILITY, may use the regular
    84 "def" result with attribute "abs_def" to imitate the old version.
    85 
    86 * Renamed some inner syntax categories:
    87 
    88     num ~> num_token
    89     xnum ~> xnum_token
    90     xstr ~> str_token
    91 
    92 Minor INCOMPATIBILITY.  Note that in practice "num_const" or
    93 "num_position" etc. are mainly used instead (which also include
    94 position information via constraints).
    95 
    96 * Attribute "abs_def" turns an equation of the form "f x y == t" into
    97 "f == %x y. t", which ensures that "simp" or "unfold" steps always
    98 expand it.  This also works for object-logic equality.  (Formerly
    99 undocumented feature.)
   100 
   101 * Discontinued old "prems" fact, which used to refer to the accidental
   102 collection of foundational premises in the context (already marked as
   103 legacy since Isabelle2011).
   104 
   105 * Obsolete command 'types' has been discontinued.  Use 'type_synonym'
   106 instead.  INCOMPATIBILITY.
   107 
   108 * Old code generator for SML and its commands 'code_module',
   109 'code_library', 'consts_code', 'types_code' have been discontinued.
   110 Use commands of the generic code generator instead.  INCOMPATIBILITY.
   111 
   112 * Redundant attribute "code_inline" has been discontinued. Use
   113 "code_unfold" instead.  INCOMPATIBILITY.
   114 
   115 * Dropped attribute "code_unfold_post" in favor of the its dual
   116 "code_abbrev", which yields a common pattern in definitions like
   117 
   118   definition [code_abbrev]: "f = t"
   119 
   120 INCOMPATIBILITY.
   121 
   122 * Sort constraints are now propagated in simultaneous statements, just
   123 like type constraints.  INCOMPATIBILITY in rare situations, where
   124 distinct sorts used to be assigned accidentally.  For example:
   125 
   126   lemma "P (x::'a::foo)" and "Q (y::'a::bar)"  -- "now illegal"
   127 
   128   lemma "P (x::'a)" and "Q (y::'a::bar)"
   129     -- "now uniform 'a::bar instead of default sort for first occurrence (!)"
   130 
   131 
   132 *** HOL ***
   133 
   134 * New tutorial "Programming and Proving in Isabelle/HOL"
   135 ("prog-prove").  It completely supersedes "A Tutorial Introduction to
   136 Structured Isar Proofs" ("isar-overview"), which has been removed.  It
   137 also supersedes "Isabelle/HOL, A Proof Assistant for Higher-Order
   138 Logic" as the recommended beginners tutorial, but does not cover all
   139 of the material of that old tutorial.
   140 
   141 * Type 'a set is now a proper type constructor (just as before
   142 Isabelle2008).  Definitions mem_def and Collect_def have disappeared.
   143 Non-trivial INCOMPATIBILITY.  For developments keeping predicates and
   144 sets separate, it is often sufficient to rephrase sets S accidentally
   145 used as predicates by "%x. x : S" and predicates P accidentally used
   146 as sets by "{x. P x}".  Corresponding proofs in a first step should be
   147 pruned from any tinkering with former theorems mem_def and Collect_def
   148 as far as possible.
   149 
   150 For developments which deliberately mixed predicates and sets, a
   151 planning step is necessary to determine what should become a predicate
   152 and what a set.  It can be helpful to carry out that step in
   153 Isabelle2011-1 before jumping right into the current release.
   154 
   155 * The representation of numerals has changed.  Datatype "num"
   156 represents strictly positive binary numerals, along with functions
   157 "numeral :: num => 'a" and "neg_numeral :: num => 'a" to represent
   158 positive and negated numeric literals, respectively. (See definitions
   159 in ~~/src/HOL/Num.thy.) Potential INCOMPATIBILITY, some user theories
   160 may require adaptations as follows:
   161 
   162   - Theorems with number_ring or number_semiring constraints: These
   163     classes are gone; use comm_ring_1 or comm_semiring_1 instead.
   164 
   165   - Theories defining numeric types: Remove number, number_semiring,
   166     and number_ring instances. Defer all theorems about numerals until
   167     after classes one and semigroup_add have been instantiated.
   168 
   169   - Numeral-only simp rules: Replace each rule having a "number_of v"
   170     pattern with two copies, one for numeral and one for neg_numeral.
   171 
   172   - Theorems about subclasses of semiring_1 or ring_1: These classes
   173     automatically support numerals now, so more simp rules and
   174     simprocs may now apply within the proof.
   175 
   176   - Definitions and theorems using old constructors Pls/Min/Bit0/Bit1:
   177     Redefine using other integer operations.
   178 
   179 * Code generation by default implements sets as container type rather
   180 than predicates.  INCOMPATIBILITY.
   181 
   182 * New proof import from HOL Light: Faster, simpler, and more scalable.
   183 Requires a proof bundle, which is available as an external component.
   184 Discontinued old (and mostly dead) Importer for HOL4 and HOL Light.
   185 INCOMPATIBILITY.
   186 
   187 * New type synonym 'a rel = ('a * 'a) set
   188 
   189 * Typedef with implicit set definition is considered legacy.  Use
   190 "typedef (open)" form instead, which will eventually become the
   191 default.
   192 
   193 * More default pred/set conversions on a couple of relation operations
   194 and predicates.  Added powers of predicate relations.  Consolidation
   195 of some relation theorems:
   196 
   197   converse_def ~> converse_unfold
   198   rel_comp_def ~> relcomp_unfold
   199   symp_def ~> (dropped, use symp_def and sym_def instead)
   200   transp_def ~> transp_trans
   201   Domain_def ~> Domain_unfold
   202   Range_def ~> Domain_converse [symmetric]
   203 
   204 Generalized theorems INF_INT_eq, INF_INT_eq2, SUP_UN_eq, SUP_UN_eq2.
   205 
   206 See theory "Relation" for examples for making use of pred/set
   207 conversions by means of attributes "to_set" and "to_pred".
   208 
   209 INCOMPATIBILITY.
   210 
   211 * Renamed facts about the power operation on relations, i.e., relpow
   212 to match the constant's name:
   213 
   214   rel_pow_1 ~> relpow_1
   215   rel_pow_0_I ~> relpow_0_I
   216   rel_pow_Suc_I ~> relpow_Suc_I
   217   rel_pow_Suc_I2 ~> relpow_Suc_I2
   218   rel_pow_0_E ~> relpow_0_E
   219   rel_pow_Suc_E ~> relpow_Suc_E
   220   rel_pow_E ~> relpow_E
   221   rel_pow_Suc_D2 ~> relpow_Suc_D2
   222   rel_pow_Suc_E2 ~> relpow_Suc_E2
   223   rel_pow_Suc_D2' ~> relpow_Suc_D2'
   224   rel_pow_E2 ~> relpow_E2
   225   rel_pow_add ~> relpow_add
   226   rel_pow_commute ~> relpow
   227   rel_pow_empty ~> relpow_empty:
   228   rtrancl_imp_UN_rel_pow ~> rtrancl_imp_UN_relpow
   229   rel_pow_imp_rtrancl ~> relpow_imp_rtrancl
   230   rtrancl_is_UN_rel_pow ~> rtrancl_is_UN_relpow
   231   rtrancl_imp_rel_pow ~> rtrancl_imp_relpow
   232   rel_pow_fun_conv ~> relpow_fun_conv
   233   rel_pow_finite_bounded1 ~> relpow_finite_bounded1
   234   rel_pow_finite_bounded ~> relpow_finite_bounded
   235   rtrancl_finite_eq_rel_pow ~> rtrancl_finite_eq_relpow
   236   trancl_finite_eq_rel_pow ~> trancl_finite_eq_relpow
   237   single_valued_rel_pow ~> single_valued_relpow
   238 
   239 INCOMPATIBILITY.
   240 
   241 * Theory Relation: Consolidated constant name for relation composition
   242 and corresponding theorem names:
   243 
   244   - Renamed constant rel_comp to relcomp.
   245 
   246   - Dropped abbreviation pred_comp. Use relcompp instead.
   247 
   248   - Renamed theorems:
   249 
   250     rel_compI ~> relcompI
   251     rel_compEpair ~> relcompEpair
   252     rel_compE ~> relcompE
   253     pred_comp_rel_comp_eq ~> relcompp_relcomp_eq
   254     rel_comp_empty1 ~> relcomp_empty1
   255     rel_comp_mono ~> relcomp_mono
   256     rel_comp_subset_Sigma ~> relcomp_subset_Sigma
   257     rel_comp_distrib ~> relcomp_distrib
   258     rel_comp_distrib2 ~> relcomp_distrib2
   259     rel_comp_UNION_distrib ~> relcomp_UNION_distrib
   260     rel_comp_UNION_distrib2 ~> relcomp_UNION_distrib2
   261     single_valued_rel_comp ~> single_valued_relcomp
   262     rel_comp_def ~> relcomp_unfold
   263     converse_rel_comp ~> converse_relcomp
   264     pred_compI ~> relcomppI
   265     pred_compE ~> relcomppE
   266     pred_comp_bot1 ~> relcompp_bot1
   267     pred_comp_bot2 ~> relcompp_bot2
   268     transp_pred_comp_less_eq ~> transp_relcompp_less_eq
   269     pred_comp_mono ~> relcompp_mono
   270     pred_comp_distrib ~> relcompp_distrib
   271     pred_comp_distrib2 ~> relcompp_distrib2
   272     converse_pred_comp ~> converse_relcompp
   273 
   274     finite_rel_comp ~> finite_relcomp
   275 
   276     set_rel_comp ~> set_relcomp
   277 
   278 INCOMPATIBILITY.
   279 
   280 * Theory Divides: Discontinued redundant theorems about div and mod.
   281 INCOMPATIBILITY, use the corresponding generic theorems instead.
   282 
   283   DIVISION_BY_ZERO ~> div_by_0, mod_by_0
   284   zdiv_self ~> div_self
   285   zmod_self ~> mod_self
   286   zdiv_zero ~> div_0
   287   zmod_zero ~> mod_0
   288   zdiv_zmod_equality ~> div_mod_equality2
   289   zdiv_zmod_equality2 ~> div_mod_equality
   290   zmod_zdiv_trivial ~> mod_div_trivial
   291   zdiv_zminus_zminus ~> div_minus_minus
   292   zmod_zminus_zminus ~> mod_minus_minus
   293   zdiv_zminus2 ~> div_minus_right
   294   zmod_zminus2 ~> mod_minus_right
   295   zdiv_minus1_right ~> div_minus1_right
   296   zmod_minus1_right ~> mod_minus1_right
   297   zdvd_mult_div_cancel ~> dvd_mult_div_cancel
   298   zmod_zmult1_eq ~> mod_mult_right_eq
   299   zpower_zmod ~> power_mod
   300   zdvd_zmod ~> dvd_mod
   301   zdvd_zmod_imp_zdvd ~> dvd_mod_imp_dvd
   302   mod_mult_distrib ~> mult_mod_left
   303   mod_mult_distrib2 ~> mult_mod_right
   304 
   305 * Removed redundant theorems nat_mult_2 and nat_mult_2_right; use
   306 generic mult_2 and mult_2_right instead. INCOMPATIBILITY.
   307 
   308 * Finite_Set.fold now qualified.  INCOMPATIBILITY.
   309 
   310 * Consolidated theorem names concerning fold combinators:
   311 
   312   inf_INFI_fold_inf ~> inf_INF_fold_inf
   313   sup_SUPR_fold_sup ~> sup_SUP_fold_sup
   314   INFI_fold_inf ~> INF_fold_inf
   315   SUPR_fold_sup ~> SUP_fold_sup
   316   union_set ~> union_set_fold
   317   minus_set ~> minus_set_fold
   318   INFI_set_fold ~> INF_set_fold
   319   SUPR_set_fold ~> SUP_set_fold
   320   INF_code ~> INF_set_foldr
   321   SUP_code ~> SUP_set_foldr
   322   foldr.simps ~> foldr.simps (in point-free formulation)
   323   foldr_fold_rev ~> foldr_conv_fold
   324   foldl_fold ~> foldl_conv_fold
   325   foldr_foldr ~> foldr_conv_foldl
   326   foldl_foldr ~> foldl_conv_foldr
   327   fold_set_remdups ~> fold_set_fold_remdups
   328   fold_set ~> fold_set_fold
   329   fold1_set ~> fold1_set_fold
   330 
   331 INCOMPATIBILITY.
   332 
   333 * Dropped rarely useful theorems concerning fold combinators:
   334 foldl_apply, foldl_fun_comm, foldl_rev, fold_weak_invariant,
   335 rev_foldl_cons, fold_set_remdups, fold_set, fold_set1,
   336 concat_conv_foldl, foldl_weak_invariant, foldl_invariant,
   337 foldr_invariant, foldl_absorb0, foldl_foldr1_lemma, foldl_foldr1,
   338 listsum_conv_fold, listsum_foldl, sort_foldl_insort, foldl_assoc,
   339 foldr_conv_foldl, start_le_sum, elem_le_sum, sum_eq_0_conv.
   340 INCOMPATIBILITY.  For the common phrases "%xs. List.foldr plus xs 0"
   341 and "List.foldl plus 0", prefer "List.listsum".  Otherwise it can be
   342 useful to boil down "List.foldr" and "List.foldl" to "List.fold" by
   343 unfolding "foldr_conv_fold" and "foldl_conv_fold".
   344 
   345 * Dropped lemmas minus_set_foldr, union_set_foldr, union_coset_foldr,
   346 inter_coset_foldr, Inf_fin_set_foldr, Sup_fin_set_foldr,
   347 Min_fin_set_foldr, Max_fin_set_foldr, Inf_set_foldr, Sup_set_foldr,
   348 INF_set_foldr, SUP_set_foldr.  INCOMPATIBILITY.  Prefer corresponding
   349 lemmas over fold rather than foldr, or make use of lemmas
   350 fold_conv_foldr and fold_rev.
   351 
   352 * Congruence rules Option.map_cong and Option.bind_cong for recursion
   353 through option types.
   354 
   355 * Concrete syntax for case expressions includes constraints for source
   356 positions, and thus produces Prover IDE markup for its bindings.
   357 INCOMPATIBILITY for old-style syntax translations that augment the
   358 pattern notation; e.g. see src/HOL/HOLCF/One.thy for translations of
   359 one_case.
   360 
   361 * Discontinued configuration option "syntax_positions": atomic terms
   362 in parse trees are always annotated by position constraints.
   363 
   364 * HOL/Library/Set_Algebras.thy: Addition and multiplication on sets
   365 are expressed via type classes again. The special syntax
   366 \<oplus>/\<otimes> has been replaced by plain +/*. Removed constant
   367 setsum_set, which is now subsumed by Big_Operators.setsum.
   368 INCOMPATIBILITY.
   369 
   370 * New theory HOL/Library/DAList provides an abstract type for
   371 association lists with distinct keys.
   372 
   373 * 'datatype' specifications allow explicit sort constraints.
   374 
   375 * Theory HOL/Library/Diagonalize has been removed. INCOMPATIBILITY,
   376 use theory HOL/Library/Nat_Bijection instead.
   377 
   378 * Theory HOL/Library/RBT_Impl: Backing implementation of red-black
   379 trees is now inside a type class context.  Names of affected
   380 operations and lemmas have been prefixed by rbt_.  INCOMPATIBILITY for
   381 theories working directly with raw red-black trees, adapt the names as
   382 follows:
   383 
   384   Operations:
   385   bulkload -> rbt_bulkload
   386   del_from_left -> rbt_del_from_left
   387   del_from_right -> rbt_del_from_right
   388   del -> rbt_del
   389   delete -> rbt_delete
   390   ins -> rbt_ins
   391   insert -> rbt_insert
   392   insertw -> rbt_insert_with
   393   insert_with_key -> rbt_insert_with_key
   394   map_entry -> rbt_map_entry
   395   lookup -> rbt_lookup
   396   sorted -> rbt_sorted
   397   tree_greater -> rbt_greater
   398   tree_less -> rbt_less
   399   tree_less_symbol -> rbt_less_symbol
   400   union -> rbt_union
   401   union_with -> rbt_union_with
   402   union_with_key -> rbt_union_with_key
   403 
   404   Lemmas:
   405   balance_left_sorted -> balance_left_rbt_sorted
   406   balance_left_tree_greater -> balance_left_rbt_greater
   407   balance_left_tree_less -> balance_left_rbt_less
   408   balance_right_sorted -> balance_right_rbt_sorted
   409   balance_right_tree_greater -> balance_right_rbt_greater
   410   balance_right_tree_less -> balance_right_rbt_less
   411   balance_sorted -> balance_rbt_sorted
   412   balance_tree_greater -> balance_rbt_greater
   413   balance_tree_less -> balance_rbt_less
   414   bulkload_is_rbt -> rbt_bulkload_is_rbt
   415   combine_sorted -> combine_rbt_sorted
   416   combine_tree_greater -> combine_rbt_greater
   417   combine_tree_less -> combine_rbt_less
   418   delete_in_tree -> rbt_delete_in_tree
   419   delete_is_rbt -> rbt_delete_is_rbt
   420   del_from_left_tree_greater -> rbt_del_from_left_rbt_greater
   421   del_from_left_tree_less -> rbt_del_from_left_rbt_less
   422   del_from_right_tree_greater -> rbt_del_from_right_rbt_greater
   423   del_from_right_tree_less -> rbt_del_from_right_rbt_less
   424   del_in_tree -> rbt_del_in_tree
   425   del_inv1_inv2 -> rbt_del_inv1_inv2
   426   del_sorted -> rbt_del_rbt_sorted
   427   del_tree_greater -> rbt_del_rbt_greater
   428   del_tree_less -> rbt_del_rbt_less
   429   dom_lookup_Branch -> dom_rbt_lookup_Branch
   430   entries_lookup -> entries_rbt_lookup
   431   finite_dom_lookup -> finite_dom_rbt_lookup
   432   insert_sorted -> rbt_insert_rbt_sorted
   433   insertw_is_rbt -> rbt_insertw_is_rbt
   434   insertwk_is_rbt -> rbt_insertwk_is_rbt
   435   insertwk_sorted -> rbt_insertwk_rbt_sorted
   436   insertw_sorted -> rbt_insertw_rbt_sorted
   437   ins_sorted -> ins_rbt_sorted
   438   ins_tree_greater -> ins_rbt_greater
   439   ins_tree_less -> ins_rbt_less
   440   is_rbt_sorted -> is_rbt_rbt_sorted
   441   lookup_balance -> rbt_lookup_balance
   442   lookup_bulkload -> rbt_lookup_rbt_bulkload
   443   lookup_delete -> rbt_lookup_rbt_delete
   444   lookup_Empty -> rbt_lookup_Empty
   445   lookup_from_in_tree -> rbt_lookup_from_in_tree
   446   lookup_in_tree -> rbt_lookup_in_tree
   447   lookup_ins -> rbt_lookup_ins
   448   lookup_insert -> rbt_lookup_rbt_insert
   449   lookup_insertw -> rbt_lookup_rbt_insertw
   450   lookup_insertwk -> rbt_lookup_rbt_insertwk
   451   lookup_keys -> rbt_lookup_keys
   452   lookup_map -> rbt_lookup_map
   453   lookup_map_entry -> rbt_lookup_rbt_map_entry
   454   lookup_tree_greater -> rbt_lookup_rbt_greater
   455   lookup_tree_less -> rbt_lookup_rbt_less
   456   lookup_union -> rbt_lookup_rbt_union
   457   map_entry_color_of -> rbt_map_entry_color_of
   458   map_entry_inv1 -> rbt_map_entry_inv1
   459   map_entry_inv2 -> rbt_map_entry_inv2
   460   map_entry_is_rbt -> rbt_map_entry_is_rbt
   461   map_entry_sorted -> rbt_map_entry_rbt_sorted
   462   map_entry_tree_greater -> rbt_map_entry_rbt_greater
   463   map_entry_tree_less -> rbt_map_entry_rbt_less
   464   map_tree_greater -> map_rbt_greater
   465   map_tree_less -> map_rbt_less
   466   map_sorted -> map_rbt_sorted
   467   paint_sorted -> paint_rbt_sorted
   468   paint_lookup -> paint_rbt_lookup
   469   paint_tree_greater -> paint_rbt_greater
   470   paint_tree_less -> paint_rbt_less
   471   sorted_entries -> rbt_sorted_entries
   472   tree_greater_eq_trans -> rbt_greater_eq_trans
   473   tree_greater_nit -> rbt_greater_nit
   474   tree_greater_prop -> rbt_greater_prop
   475   tree_greater_simps -> rbt_greater_simps
   476   tree_greater_trans -> rbt_greater_trans
   477   tree_less_eq_trans -> rbt_less_eq_trans
   478   tree_less_nit -> rbt_less_nit
   479   tree_less_prop -> rbt_less_prop
   480   tree_less_simps -> rbt_less_simps
   481   tree_less_trans -> rbt_less_trans
   482   tree_ord_props -> rbt_ord_props
   483   union_Branch -> rbt_union_Branch
   484   union_is_rbt -> rbt_union_is_rbt
   485   unionw_is_rbt -> rbt_unionw_is_rbt
   486   unionwk_is_rbt -> rbt_unionwk_is_rbt
   487   unionwk_sorted -> rbt_unionwk_rbt_sorted
   488 
   489 * Theory HOL/Library/Float: Floating point numbers are now defined as a
   490 subset of the real numbers. All operations are defined using the
   491 lifing-framework and proofs use the transfer method.
   492 INCOMPATIBILITY.
   493 
   494   Changed Operations:
   495   float_abs -> abs
   496   float_nprt -> nprt
   497   float_pprt -> pprt
   498   pow2 -> use powr
   499   round_down -> float_round_down
   500   round_up -> float_round_up
   501   scale -> exponent
   502 
   503   Removed Operations:
   504   ceiling_fl, lb_mult, lb_mod, ub_mult, ub_mod
   505 
   506   Renamed Lemmas:
   507   abs_float_def -> Float.compute_float_abs
   508   bitlen_ge0 -> bitlen_nonneg
   509   bitlen.simps -> Float.compute_bitlen
   510   float_components -> Float_mantissa_exponent
   511   float_divl.simps -> Float.compute_float_divl
   512   float_divr.simps -> Float.compute_float_divr
   513   float_eq_odd -> mult_powr_eq_mult_powr_iff
   514   float_power -> real_of_float_power
   515   lapprox_posrat_def -> Float.compute_lapprox_posrat
   516   lapprox_rat.simps -> Float.compute_lapprox_rat
   517   le_float_def' -> Float.compute_float_le
   518   le_float_def -> less_eq_float.rep_eq
   519   less_float_def' -> Float.compute_float_less
   520   less_float_def -> less_float.rep_eq
   521   normfloat_def -> Float.compute_normfloat
   522   normfloat_imp_odd_or_zero -> mantissa_not_dvd and mantissa_noteq_0
   523   normfloat -> normfloat_def
   524   normfloat_unique -> use normfloat_def
   525   number_of_float_Float -> Float.compute_float_numeral, Float.compute_float_neg_numeral
   526   one_float_def -> Float.compute_float_one
   527   plus_float_def -> Float.compute_float_plus
   528   rapprox_posrat_def -> Float.compute_rapprox_posrat
   529   rapprox_rat.simps -> Float.compute_rapprox_rat
   530   real_of_float_0 -> zero_float.rep_eq
   531   real_of_float_1 -> one_float.rep_eq
   532   real_of_float_abs -> abs_float.rep_eq
   533   real_of_float_add -> plus_float.rep_eq
   534   real_of_float_minus -> uminus_float.rep_eq
   535   real_of_float_mult -> times_float.rep_eq
   536   real_of_float_simp -> Float.rep_eq
   537   real_of_float_sub -> minus_float.rep_eq
   538   round_down.simps -> Float.compute_float_round_down
   539   round_up.simps -> Float.compute_float_round_up
   540   times_float_def -> Float.compute_float_times
   541   uminus_float_def -> Float.compute_float_uminus
   542   zero_float_def -> Float.compute_float_zero
   543 
   544   Lemmas not necessary anymore, use the transfer method:
   545   bitlen_B0, bitlen_B1, bitlen_ge1, bitlen_Min, bitlen_Pls, float_divl,
   546   float_divr, float_le_simp, float_less1_mantissa_bound,
   547   float_less_simp, float_less_zero, float_le_zero,
   548   float_pos_less1_e_neg, float_pos_m_pos, float_split, float_split2,
   549   floor_pos_exp, lapprox_posrat, lapprox_posrat_bottom, lapprox_rat,
   550   lapprox_rat_bottom, normalized_float, rapprox_posrat,
   551   rapprox_posrat_le1, rapprox_rat, real_of_float_ge0_exp,
   552   real_of_float_neg_exp, real_of_float_nge0_exp, round_down floor_fl,
   553   round_up, zero_le_float, zero_less_float
   554 
   555 * Session HOL-Word: Discontinued many redundant theorems specific to
   556 type 'a word. INCOMPATIBILITY, use the corresponding generic theorems
   557 instead.
   558 
   559   word_sub_alt ~> word_sub_wi
   560   word_add_alt ~> word_add_def
   561   word_mult_alt ~> word_mult_def
   562   word_minus_alt ~> word_minus_def
   563   word_0_alt ~> word_0_wi
   564   word_1_alt ~> word_1_wi
   565   word_add_0 ~> add_0_left
   566   word_add_0_right ~> add_0_right
   567   word_mult_1 ~> mult_1_left
   568   word_mult_1_right ~> mult_1_right
   569   word_add_commute ~> add_commute
   570   word_add_assoc ~> add_assoc
   571   word_add_left_commute ~> add_left_commute
   572   word_mult_commute ~> mult_commute
   573   word_mult_assoc ~> mult_assoc
   574   word_mult_left_commute ~> mult_left_commute
   575   word_left_distrib ~> left_distrib
   576   word_right_distrib ~> right_distrib
   577   word_left_minus ~> left_minus
   578   word_diff_0_right ~> diff_0_right
   579   word_diff_self ~> diff_self
   580   word_sub_def ~> diff_minus
   581   word_diff_minus ~> diff_minus
   582   word_add_ac ~> add_ac
   583   word_mult_ac ~> mult_ac
   584   word_plus_ac0 ~> add_0_left add_0_right add_ac
   585   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
   586   word_order_trans ~> order_trans
   587   word_order_refl ~> order_refl
   588   word_order_antisym ~> order_antisym
   589   word_order_linear ~> linorder_linear
   590   lenw1_zero_neq_one ~> zero_neq_one
   591   word_number_of_eq ~> number_of_eq
   592   word_of_int_add_hom ~> wi_hom_add
   593   word_of_int_sub_hom ~> wi_hom_sub
   594   word_of_int_mult_hom ~> wi_hom_mult
   595   word_of_int_minus_hom ~> wi_hom_neg
   596   word_of_int_succ_hom ~> wi_hom_succ
   597   word_of_int_pred_hom ~> wi_hom_pred
   598   word_of_int_0_hom ~> word_0_wi
   599   word_of_int_1_hom ~> word_1_wi
   600 
   601 * New tactic "word_bitwise" for splitting machine word equalities and
   602 inequalities into logical circuits. Requires theory "WordBitwise" from HOL-Word
   603 session. Supports addition, subtraction, multiplication, shifting by
   604 constants, bitwise operators and numeric constants. Requires fixed-length word
   605 types, cannot operate on 'a word. Solves many standard word identies outright
   606 and converts more into first order problems amenable to blast or similar. See
   607 HOL/Word/WordBitwise.thy and examples in HOL/Word/Examples/WordExamples.thy.
   608 
   609 * Clarified attribute "mono_set": pure declaration without modifying
   610 the result of the fact expression.
   611 
   612 * "Transitive_Closure.ntrancl": bounded transitive closure on
   613 relations.
   614 
   615 * Constant "Set.not_member" now qualified.  INCOMPATIBILITY.
   616 
   617 * Theory Int: Discontinued many legacy theorems specific to type int.
   618 INCOMPATIBILITY, use the corresponding generic theorems instead.
   619 
   620   zminus_zminus ~> minus_minus
   621   zminus_0 ~> minus_zero
   622   zminus_zadd_distrib ~> minus_add_distrib
   623   zadd_commute ~> add_commute
   624   zadd_assoc ~> add_assoc
   625   zadd_left_commute ~> add_left_commute
   626   zadd_ac ~> add_ac
   627   zmult_ac ~> mult_ac
   628   zadd_0 ~> add_0_left
   629   zadd_0_right ~> add_0_right
   630   zadd_zminus_inverse2 ~> left_minus
   631   zmult_zminus ~> mult_minus_left
   632   zmult_commute ~> mult_commute
   633   zmult_assoc ~> mult_assoc
   634   zadd_zmult_distrib ~> left_distrib
   635   zadd_zmult_distrib2 ~> right_distrib
   636   zdiff_zmult_distrib ~> left_diff_distrib
   637   zdiff_zmult_distrib2 ~> right_diff_distrib
   638   zmult_1 ~> mult_1_left
   639   zmult_1_right ~> mult_1_right
   640   zle_refl ~> order_refl
   641   zle_trans ~> order_trans
   642   zle_antisym ~> order_antisym
   643   zle_linear ~> linorder_linear
   644   zless_linear ~> linorder_less_linear
   645   zadd_left_mono ~> add_left_mono
   646   zadd_strict_right_mono ~> add_strict_right_mono
   647   zadd_zless_mono ~> add_less_le_mono
   648   int_0_less_1 ~> zero_less_one
   649   int_0_neq_1 ~> zero_neq_one
   650   zless_le ~> less_le
   651   zpower_zadd_distrib ~> power_add
   652   zero_less_zpower_abs_iff ~> zero_less_power_abs_iff
   653   zero_le_zpower_abs ~> zero_le_power_abs
   654 
   655 * Theory Deriv: Renamed
   656 
   657   DERIV_nonneg_imp_nonincreasing ~> DERIV_nonneg_imp_nondecreasing
   658 
   659 * Theory Library/Multiset: Improved code generation of multisets.
   660 
   661 * Session HOL-Probability: Introduced the type "'a measure" to represent
   662 measures, this replaces the records 'a algebra and 'a measure_space. The
   663 locales based on subset_class now have two locale-parameters the space
   664 \<Omega> and the set of measurables sets M. The product of probability spaces
   665 uses now the same constant as the finite product of sigma-finite measure
   666 spaces "PiM :: ('i => 'a) measure". Most constants are defined now
   667 outside of locales and gain an additional parameter, like null_sets,
   668 almost_eventually or \<mu>'. Measure space constructions for distributions
   669 and densities now got their own constants distr and density. Instead of
   670 using locales to describe measure spaces with a finite space, the
   671 measure count_space and point_measure is introduced. INCOMPATIBILITY.
   672 
   673   Renamed constants:
   674   measure -> emeasure
   675   finite_measure.\<mu>' -> measure
   676   product_algebra_generator -> prod_algebra
   677   product_prob_space.emb -> prod_emb
   678   product_prob_space.infprod_algebra -> PiM
   679 
   680   Removed locales:
   681   completeable_measure_space
   682   finite_measure_space
   683   finite_prob_space
   684   finite_product_finite_prob_space
   685   finite_product_sigma_algebra
   686   finite_sigma_algebra
   687   measure_space
   688   pair_finite_prob_space
   689   pair_finite_sigma_algebra
   690   pair_finite_space
   691   pair_sigma_algebra
   692   product_sigma_algebra
   693 
   694   Removed constants:
   695   conditional_space
   696   distribution -> use distr measure, or distributed predicate
   697   image_space
   698   joint_distribution -> use distr measure, or distributed predicate
   699   pair_measure_generator
   700   product_prob_space.infprod_algebra -> use PiM
   701   subvimage
   702 
   703   Replacement theorems:
   704   finite_additivity_sufficient -> ring_of_sets.countably_additiveI_finite
   705   finite_measure.empty_measure -> measure_empty
   706   finite_measure.finite_continuity_from_above -> finite_measure.finite_Lim_measure_decseq
   707   finite_measure.finite_continuity_from_below -> finite_measure.finite_Lim_measure_incseq
   708   finite_measure.finite_measure_countably_subadditive -> finite_measure.finite_measure_subadditive_countably
   709   finite_measure.finite_measure_eq -> finite_measure.emeasure_eq_measure
   710   finite_measure.finite_measure -> finite_measure.emeasure_finite
   711   finite_measure.finite_measure_finite_singleton -> finite_measure.finite_measure_eq_setsum_singleton
   712   finite_measure.positive_measure' -> measure_nonneg
   713   finite_measure.real_measure -> finite_measure.emeasure_real
   714   finite_product_prob_space.finite_measure_times -> finite_product_prob_space.finite_measure_PiM_emb
   715   finite_product_sigma_algebra.in_P -> sets_PiM_I_finite
   716   finite_product_sigma_algebra.P_empty -> space_PiM_empty, sets_PiM_empty
   717   information_space.conditional_entropy_eq -> information_space.conditional_entropy_simple_distributed
   718   information_space.conditional_entropy_positive -> information_space.conditional_entropy_nonneg_simple
   719   information_space.conditional_mutual_information_eq_mutual_information -> information_space.conditional_mutual_information_eq_mutual_information_simple
   720   information_space.conditional_mutual_information_generic_positive -> information_space.conditional_mutual_information_nonneg_simple
   721   information_space.conditional_mutual_information_positive -> information_space.conditional_mutual_information_nonneg_simple
   722   information_space.entropy_commute -> information_space.entropy_commute_simple
   723   information_space.entropy_eq -> information_space.entropy_simple_distributed
   724   information_space.entropy_generic_eq -> information_space.entropy_simple_distributed
   725   information_space.entropy_positive -> information_space.entropy_nonneg_simple
   726   information_space.entropy_uniform_max -> information_space.entropy_uniform
   727   information_space.KL_eq_0_imp -> information_space.KL_eq_0_iff_eq
   728   information_space.KL_eq_0 -> information_space.KL_same_eq_0
   729   information_space.KL_ge_0 -> information_space.KL_nonneg
   730   information_space.mutual_information_eq -> information_space.mutual_information_simple_distributed
   731   information_space.mutual_information_positive -> information_space.mutual_information_nonneg_simple
   732   Int_stable_cuboids -> Int_stable_atLeastAtMost
   733   Int_stable_product_algebra_generator -> positive_integral
   734   measure_preserving -> equality "distr M N f = N" "f : measurable M N"
   735   measure_space.additive -> emeasure_additive
   736   measure_space.AE_iff_null_set -> AE_iff_null
   737   measure_space.almost_everywhere_def -> eventually_ae_filter
   738   measure_space.almost_everywhere_vimage -> AE_distrD
   739   measure_space.continuity_from_above -> INF_emeasure_decseq
   740   measure_space.continuity_from_above_Lim -> Lim_emeasure_decseq
   741   measure_space.continuity_from_below_Lim -> Lim_emeasure_incseq
   742   measure_space.continuity_from_below -> SUP_emeasure_incseq
   743   measure_space_density -> emeasure_density
   744   measure_space.density_is_absolutely_continuous -> absolutely_continuousI_density
   745   measure_space.integrable_vimage -> integrable_distr
   746   measure_space.integral_translated_density -> integral_density
   747   measure_space.integral_vimage -> integral_distr
   748   measure_space.measure_additive -> plus_emeasure
   749   measure_space.measure_compl -> emeasure_compl
   750   measure_space.measure_countable_increasing -> emeasure_countable_increasing
   751   measure_space.measure_countably_subadditive -> emeasure_subadditive_countably
   752   measure_space.measure_decseq -> decseq_emeasure
   753   measure_space.measure_Diff -> emeasure_Diff
   754   measure_space.measure_Diff_null_set -> emeasure_Diff_null_set
   755   measure_space.measure_eq_0 -> emeasure_eq_0
   756   measure_space.measure_finitely_subadditive -> emeasure_subadditive_finite
   757   measure_space.measure_finite_singleton -> emeasure_eq_setsum_singleton
   758   measure_space.measure_incseq -> incseq_emeasure
   759   measure_space.measure_insert -> emeasure_insert
   760   measure_space.measure_mono -> emeasure_mono
   761   measure_space.measure_not_negative -> emeasure_not_MInf
   762   measure_space.measure_preserving_Int_stable -> measure_eqI_generator_eq
   763   measure_space.measure_setsum -> setsum_emeasure
   764   measure_space.measure_setsum_split -> setsum_emeasure_cover
   765   measure_space.measure_space_vimage -> emeasure_distr
   766   measure_space.measure_subadditive_finite -> emeasure_subadditive_finite
   767   measure_space.measure_subadditive -> subadditive
   768   measure_space.measure_top -> emeasure_space
   769   measure_space.measure_UN_eq_0 -> emeasure_UN_eq_0
   770   measure_space.measure_Un_null_set -> emeasure_Un_null_set
   771   measure_space.positive_integral_translated_density -> positive_integral_density
   772   measure_space.positive_integral_vimage -> positive_integral_distr
   773   measure_space.real_continuity_from_above -> Lim_measure_decseq
   774   measure_space.real_continuity_from_below -> Lim_measure_incseq
   775   measure_space.real_measure_countably_subadditive -> measure_subadditive_countably
   776   measure_space.real_measure_Diff -> measure_Diff
   777   measure_space.real_measure_finite_Union -> measure_finite_Union
   778   measure_space.real_measure_setsum_singleton -> measure_eq_setsum_singleton
   779   measure_space.real_measure_subadditive -> measure_subadditive
   780   measure_space.real_measure_Union -> measure_Union
   781   measure_space.real_measure_UNION -> measure_UNION
   782   measure_space.simple_function_vimage -> simple_function_comp
   783   measure_space.simple_integral_vimage -> simple_integral_distr
   784   measure_space.simple_integral_vimage -> simple_integral_distr
   785   measure_unique_Int_stable -> measure_eqI_generator_eq
   786   measure_unique_Int_stable_vimage -> measure_eqI_generator_eq
   787   pair_sigma_algebra.measurable_cut_fst -> sets_Pair1
   788   pair_sigma_algebra.measurable_cut_snd -> sets_Pair2
   789   pair_sigma_algebra.measurable_pair_image_fst -> measurable_Pair1
   790   pair_sigma_algebra.measurable_pair_image_snd -> measurable_Pair2
   791   pair_sigma_algebra.measurable_product_swap -> measurable_pair_swap_iff
   792   pair_sigma_algebra.pair_sigma_algebra_measurable -> measurable_pair_swap
   793   pair_sigma_algebra.pair_sigma_algebra_swap_measurable -> measurable_pair_swap'
   794   pair_sigma_algebra.sets_swap -> sets_pair_swap
   795   pair_sigma_finite.measure_cut_measurable_fst -> pair_sigma_finite.measurable_emeasure_Pair1
   796   pair_sigma_finite.measure_cut_measurable_snd -> pair_sigma_finite.measurable_emeasure_Pair2
   797   pair_sigma_finite.measure_preserving_swap -> pair_sigma_finite.distr_pair_swap
   798   pair_sigma_finite.pair_measure_alt2 -> pair_sigma_finite.emeasure_pair_measure_alt2
   799   pair_sigma_finite.pair_measure_alt -> pair_sigma_finite.emeasure_pair_measure_alt
   800   pair_sigma_finite.pair_measure_times -> pair_sigma_finite.emeasure_pair_measure_Times
   801   prob_space.indep_distribution_eq_measure -> prob_space.indep_vars_iff_distr_eq_PiM
   802   prob_space.indep_var_distributionD -> prob_space.indep_var_distribution_eq
   803   prob_space.measure_space_1 -> prob_space.emeasure_space_1
   804   prob_space.prob_space_vimage -> prob_space_distr
   805   prob_space.random_variable_restrict -> measurable_restrict
   806   prob_space_unique_Int_stable -> measure_eqI_prob_space
   807   product_algebraE -> prod_algebraE_all
   808   product_algebra_generator_der -> prod_algebra_eq_finite
   809   product_algebra_generator_into_space -> prod_algebra_sets_into_space
   810   product_algebraI -> sets_PiM_I_finite
   811   product_measure_exists -> product_sigma_finite.sigma_finite
   812   product_prob_space.finite_index_eq_finite_product -> product_prob_space.sets_PiM_generator
   813   product_prob_space.finite_measure_infprod_emb_Pi -> product_prob_space.measure_PiM_emb
   814   product_prob_space.infprod_spec -> product_prob_space.emeasure_PiM_emb_not_empty
   815   product_prob_space.measurable_component -> measurable_component_singleton
   816   product_prob_space.measurable_emb -> measurable_prod_emb
   817   product_prob_space.measurable_into_infprod_algebra -> measurable_PiM_single
   818   product_prob_space.measurable_singleton_infprod -> measurable_component_singleton
   819   product_prob_space.measure_emb -> emeasure_prod_emb
   820   product_prob_space.measure_preserving_restrict -> product_prob_space.distr_restrict
   821   product_sigma_algebra.product_algebra_into_space -> space_closed
   822   product_sigma_finite.measure_fold -> product_sigma_finite.distr_merge
   823   product_sigma_finite.measure_preserving_component_singelton -> product_sigma_finite.distr_singleton
   824   product_sigma_finite.measure_preserving_merge -> product_sigma_finite.distr_merge
   825   sequence_space.measure_infprod -> sequence_space.measure_PiM_countable
   826   sets_product_algebra -> sets_PiM
   827   sigma_algebra.measurable_sigma -> measurable_measure_of
   828   sigma_finite_measure.disjoint_sigma_finite -> sigma_finite_disjoint
   829   sigma_finite_measure.RN_deriv_vimage -> sigma_finite_measure.RN_deriv_distr
   830   sigma_product_algebra_sigma_eq -> sigma_prod_algebra_sigma_eq
   831   space_product_algebra -> space_PiM
   832 
   833 * New "case_product" attribute to generate a case rule doing multiple
   834 case distinctions at the same time.  E.g.
   835 
   836   list.exhaust [case_product nat.exhaust]
   837 
   838 produces a rule which can be used to perform case distinction on both
   839 a list and a nat.
   840 
   841 * New Transfer package:
   842 
   843   - transfer_rule attribute: Maintains a collection of transfer rules,
   844     which relate constants at two different types. Transfer rules may
   845     relate different type instances of the same polymorphic constant,
   846     or they may relate an operation on a raw type to a corresponding
   847     operation on an abstract type (quotient or subtype). For example:
   848 
   849     ((A ===> B) ===> list_all2 A ===> list_all2 B) map map
   850     (cr_int ===> cr_int ===> cr_int) (%(x,y) (u,v). (x+u, y+v)) plus_int
   851 
   852   - transfer method: Replaces a subgoal on abstract types with an
   853     equivalent subgoal on the corresponding raw types. Constants are
   854     replaced with corresponding ones according to the transfer rules.
   855     Goals are generalized over all free variables by default; this is
   856     necessary for variables whose types changes, but can be overridden
   857     for specific variables with e.g. 'transfer fixing: x y z'.
   858     The variant transfer' method allows replacing a subgoal with
   859     one that is logically stronger (rather than equivalent).
   860 
   861   - relator_eq attribute: Collects identity laws for relators of
   862     various type constructors, e.g. "list_all2 (op =) = (op =)". The
   863     transfer method uses these lemmas to infer transfer rules for
   864     non-polymorphic constants on the fly.
   865 
   866   - transfer_prover method: Assists with proving a transfer rule for a
   867     new constant, provided the constant is defined in terms of other
   868     constants that already have transfer rules. It should be applied
   869     after unfolding the constant definitions.
   870 
   871   - HOL/ex/Transfer_Int_Nat.thy: Example theory demonstrating transfer
   872     from type nat to type int.
   873 
   874 * New Lifting package:
   875 
   876   - lift_definition command: Defines operations on an abstract type in
   877     terms of a corresponding operation on a representation type. Example
   878     syntax:
   879 
   880     lift_definition dlist_insert :: "'a => 'a dlist => 'a dlist"
   881       is List.insert
   882 
   883     Users must discharge a respectfulness proof obligation when each
   884     constant is defined. (For a type copy, i.e. a typedef with UNIV,
   885     the proof is discharged automatically.) The obligation is
   886     presented in a user-friendly, readable form; a respectfulness
   887     theorem in the standard format and a transfer rule are generated
   888     by the package.
   889 
   890   - Integration with code_abstype: For typedefs (e.g. subtypes
   891     corresponding to a datatype invariant, such as dlist),
   892     lift_definition generates a code certificate theorem and sets up
   893     code generation for each constant.
   894 
   895   - setup_lifting command: Sets up the Lifting package to work with
   896     a user-defined type. The user must provide either a quotient
   897     theorem or a type_definition theorem. The package configures
   898     transfer rules for equality and quantifiers on the type, and sets
   899     up the lift_definition command to work with the type.
   900 
   901   - Usage examples: See Quotient_Examples/Lift_DList.thy,
   902     Quotient_Examples/Lift_RBT.thy, Word/Word.thy and
   903     Library/Float.thy.
   904 
   905 * Quotient package:
   906 
   907   - The 'quotient_type' command now supports a 'morphisms' option with
   908     rep and abs functions, similar to typedef.
   909 
   910   - 'quotient_type' sets up new types to work with the Lifting and
   911     Transfer packages, as with 'setup_lifting'.
   912 
   913   - The 'quotient_definition' command now requires the user to prove a
   914     respectfulness property at the point where the constant is
   915     defined, similar to lift_definition; INCOMPATIBILITY.
   916 
   917   - Renamed predicate 'Quotient' to 'Quotient3', and renamed theorems
   918     accordingly, INCOMPATIBILITY.
   919 
   920 * New diagnostic command 'find_unused_assms' to find potentially
   921 superfluous assumptions in theorems using Quickcheck.
   922 
   923 * Quickcheck:
   924 
   925   - Quickcheck returns variable assignments as counterexamples, which
   926     allows to reveal the underspecification of functions under test.
   927     For example, refuting "hd xs = x", it presents the variable
   928     assignment xs = [] and x = a1 as a counterexample, assuming that
   929     any property is false whenever "hd []" occurs in it.
   930 
   931     These counterexample are marked as potentially spurious, as
   932     Quickcheck also returns "xs = []" as a counterexample to the
   933     obvious theorem "hd xs = hd xs".
   934 
   935     After finding a potentially spurious counterexample, Quickcheck
   936     continues searching for genuine ones.
   937 
   938     By default, Quickcheck shows potentially spurious and genuine
   939     counterexamples. The option "genuine_only" sets quickcheck to only
   940     show genuine counterexamples.
   941 
   942   - The command 'quickcheck_generator' creates random and exhaustive
   943     value generators for a given type and operations.
   944 
   945     It generates values by using the operations as if they were
   946     constructors of that type.
   947 
   948   - Support for multisets.
   949 
   950   - Added "use_subtype" options.
   951 
   952   - Added "quickcheck_locale" configuration to specify how to process
   953     conjectures in a locale context.
   954 
   955 * Nitpick:
   956   - Fixed infinite loop caused by the 'peephole_optim' option and
   957     affecting 'rat' and 'real'.
   958 
   959 * Sledgehammer:
   960   - Integrated more tightly with SPASS, as described in the ITP 2012 paper "More
   961     SPASS with Isabelle".
   962   - Made it try "smt" as a fallback if "metis" fails or times out.
   963   - Added support for the following provers: Alt-Ergo (via Why3 and TFF1),
   964     iProver, iProver-Eq.
   965   - Replaced remote E-SInE with remote Satallax in the default setup.
   966   - Sped up the minimizer.
   967   - Added "lam_trans", "uncurry_aliases", and "minimize" options.
   968   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   969   - Renamed "sound" option to "strict".
   970 
   971 * Metis:
   972   - Added possibility to specify lambda translations scheme as a
   973     parenthesized argument (e.g., "by (metis (lifting) ...)").
   974 
   975 * SMT:
   976   - Renamed "smt_fixed" option to "smt_read_only_certificates".
   977 
   978 * Command 'try0':
   979   - Renamed from 'try_methods'. INCOMPATIBILITY.
   980 
   981 * New "eventually_elim" method as a generalized variant of the
   982 eventually_elim* rules. Supports structured proofs.
   983 
   984 * HOL/TPTP: support to parse and import TPTP problems (all languages)
   985 into Isabelle/HOL.
   986 
   987 
   988 *** FOL ***
   989 
   990 * New "case_product" attribute (see HOL).
   991 
   992 
   993 *** ZF ***
   994 
   995 * Greater support for structured proofs involving induction or case
   996 analysis.
   997 
   998 * Much greater use of mathematical symbols.
   999 
  1000 * Removal of many ML theorem bindings.  INCOMPATIBILITY.
  1001 
  1002 
  1003 *** ML ***
  1004 
  1005 * Antiquotation @{keyword "name"} produces a parser for outer syntax
  1006 from a minor keyword introduced via theory header declaration.
  1007 
  1008 * Antiquotation @{command_spec "name"} produces the
  1009 Outer_Syntax.command_spec from a major keyword introduced via theory
  1010 header declaration; it can be passed to Outer_Syntax.command etc.
  1011 
  1012 * Local_Theory.define no longer hard-wires default theorem name
  1013 "foo_def", but retains the binding as given.  If that is Binding.empty
  1014 / Attrib.empty_binding, the result is not registered as user-level
  1015 fact.  The Local_Theory.define_internal variant allows to specify a
  1016 non-empty name (used for the foundation in the background theory),
  1017 while omitting the fact binding in the user-context.  Potential
  1018 INCOMPATIBILITY for derived definitional packages: need to specify
  1019 naming policy for primitive definitions more explicitly.
  1020 
  1021 * Renamed Thm.capply to Thm.apply, and Thm.cabs to Thm.lambda in
  1022 conformance with similar operations in structure Term and Logic.
  1023 
  1024 * Antiquotation @{attributes [...]} embeds attribute source
  1025 representation into the ML text, which is particularly useful with
  1026 declarations like Local_Theory.note.
  1027 
  1028 * Structure Proof_Context follows standard naming scheme.  Old
  1029 ProofContext has been discontinued.  INCOMPATIBILITY.
  1030 
  1031 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
  1032 change of semantics: update is applied to auxiliary local theory
  1033 context as well.
  1034 
  1035 * Modernized some old-style infix operations:
  1036 
  1037   addeqcongs    ~> Simplifier.add_eqcong
  1038   deleqcongs    ~> Simplifier.del_eqcong
  1039   addcongs      ~> Simplifier.add_cong
  1040   delcongs      ~> Simplifier.del_cong
  1041   setmksimps    ~> Simplifier.set_mksimps
  1042   setmkcong     ~> Simplifier.set_mkcong
  1043   setmksym      ~> Simplifier.set_mksym
  1044   setmkeqTrue   ~> Simplifier.set_mkeqTrue
  1045   settermless   ~> Simplifier.set_termless
  1046   setsubgoaler  ~> Simplifier.set_subgoaler
  1047   addsplits     ~> Splitter.add_split
  1048   delsplits     ~> Splitter.del_split
  1049 
  1050 
  1051 *** System ***
  1052 
  1053 * USER_HOME settings variable points to cross-platform user home
  1054 directory, which coincides with HOME on POSIX systems only.  Likewise,
  1055 the Isabelle path specification "~" now expands to $USER_HOME, instead
  1056 of former $HOME.  A different default for USER_HOME may be set
  1057 explicitly in shell environment, before Isabelle settings are
  1058 evaluated.  Minor INCOMPATIBILITY: need to adapt Isabelle path where
  1059 the generic user home was intended.
  1060 
  1061 * ISABELLE_JDK_HOME settings variable points to JDK with javac and jar
  1062 (not just JRE).
  1063 
  1064 * ISABELLE_HOME_WINDOWS refers to ISABELLE_HOME in windows file name
  1065 notation, which is useful for the jEdit file browser, for example.
  1066 
  1067 
  1068 
  1069 New in Isabelle2011-1 (October 2011)
  1070 ------------------------------------
  1071 
  1072 *** General ***
  1073 
  1074 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
  1075 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
  1076 
  1077   - Management of multiple theory files directly from the editor
  1078     buffer store -- bypassing the file-system (no requirement to save
  1079     files for checking).
  1080 
  1081   - Markup of formal entities within the text buffer, with semantic
  1082     highlighting, tooltips and hyperlinks to jump to defining source
  1083     positions.
  1084 
  1085   - Improved text rendering, with sub/superscripts in the source
  1086     buffer (including support for copy/paste wrt. output panel, HTML
  1087     theory output and other non-Isabelle text boxes).
  1088 
  1089   - Refined scheduling of proof checking and printing of results,
  1090     based on interactive editor view.  (Note: jEdit folding and
  1091     narrowing allows to restrict buffer perspectives explicitly.)
  1092 
  1093   - Reduced CPU performance requirements, usable on machines with few
  1094     cores.
  1095 
  1096   - Reduced memory requirements due to pruning of unused document
  1097     versions (garbage collection).
  1098 
  1099 See also ~~/src/Tools/jEdit/README.html for further information,
  1100 including some remaining limitations.
  1101 
  1102 * Theory loader: source files are exclusively located via the master
  1103 directory of each theory node (where the .thy file itself resides).
  1104 The global load path (such as src/HOL/Library) has been discontinued.
  1105 Note that the path element ~~ may be used to reference theories in the
  1106 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
  1107 INCOMPATIBILITY.
  1108 
  1109 * Theory loader: source files are identified by content via SHA1
  1110 digests.  Discontinued former path/modtime identification and optional
  1111 ISABELLE_FILE_IDENT plugin scripts.
  1112 
  1113 * Parallelization of nested Isar proofs is subject to
  1114 Goal.parallel_proofs_threshold (default 100).  See also isabelle
  1115 usedir option -Q.
  1116 
  1117 * Name space: former unsynchronized references are now proper
  1118 configuration options, with more conventional names:
  1119 
  1120   long_names   ~> names_long
  1121   short_names  ~> names_short
  1122   unique_names ~> names_unique
  1123 
  1124 Minor INCOMPATIBILITY, need to declare options in context like this:
  1125 
  1126   declare [[names_unique = false]]
  1127 
  1128 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
  1129 that the result needs to be unique, which means fact specifications
  1130 may have to be refined after enriching a proof context.
  1131 
  1132 * Attribute "case_names" has been refined: the assumptions in each case
  1133 can be named now by following the case name with [name1 name2 ...].
  1134 
  1135 * Isabelle/Isar reference manual has been updated and extended:
  1136   - "Synopsis" provides a catalog of main Isar language concepts.
  1137   - Formal references in syntax diagrams, via @{rail} antiquotation.
  1138   - Updated material from classic "ref" manual, notably about
  1139     "Classical Reasoner".
  1140 
  1141 
  1142 *** HOL ***
  1143 
  1144 * Class bot and top require underlying partial order rather than
  1145 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
  1146 
  1147 * Class complete_lattice: generalized a couple of lemmas from sets;
  1148 generalized theorems INF_cong and SUP_cong.  New type classes for
  1149 complete boolean algebras and complete linear orders.  Lemmas
  1150 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
  1151 class complete_linorder.
  1152 
  1153 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
  1154 Sup_fun_def, Inf_apply, Sup_apply.
  1155 
  1156 Removed redundant lemmas (the right hand side gives hints how to
  1157 replace them for (metis ...), or (simp only: ...) proofs):
  1158 
  1159   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
  1160   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
  1161   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
  1162   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
  1163   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
  1164   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
  1165   Inter_def ~> INF_def, image_def
  1166   Union_def ~> SUP_def, image_def
  1167   INT_eq ~> INF_def, and image_def
  1168   UN_eq ~> SUP_def, and image_def
  1169   INF_subset ~> INF_superset_mono [OF _ order_refl]
  1170 
  1171 More consistent and comprehensive names:
  1172 
  1173   INTER_eq_Inter_image ~> INF_def
  1174   UNION_eq_Union_image ~> SUP_def
  1175   INFI_def ~> INF_def
  1176   SUPR_def ~> SUP_def
  1177   INF_leI ~> INF_lower
  1178   INF_leI2 ~> INF_lower2
  1179   le_INFI ~> INF_greatest
  1180   le_SUPI ~> SUP_upper
  1181   le_SUPI2 ~> SUP_upper2
  1182   SUP_leI ~> SUP_least
  1183   INFI_bool_eq ~> INF_bool_eq
  1184   SUPR_bool_eq ~> SUP_bool_eq
  1185   INFI_apply ~> INF_apply
  1186   SUPR_apply ~> SUP_apply
  1187   INTER_def ~> INTER_eq
  1188   UNION_def ~> UNION_eq
  1189 
  1190 INCOMPATIBILITY.
  1191 
  1192 * Renamed theory Complete_Lattice to Complete_Lattices.
  1193 INCOMPATIBILITY.
  1194 
  1195 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
  1196 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
  1197 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
  1198 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
  1199 
  1200 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
  1201 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
  1202 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
  1203 INCOMPATIBILITY.
  1204 
  1205 * Added syntactic classes "inf" and "sup" for the respective
  1206 constants.  INCOMPATIBILITY: Changes in the argument order of the
  1207 (mostly internal) locale predicates for some derived classes.
  1208 
  1209 * Theorem collections ball_simps and bex_simps do not contain theorems
  1210 referring to UNION any longer; these have been moved to collection
  1211 UN_ball_bex_simps.  INCOMPATIBILITY.
  1212 
  1213 * Theory Archimedean_Field: floor now is defined as parameter of a
  1214 separate type class floor_ceiling.
  1215 
  1216 * Theory Finite_Set: more coherent development of fold_set locales:
  1217 
  1218     locale fun_left_comm ~> locale comp_fun_commute
  1219     locale fun_left_comm_idem ~> locale comp_fun_idem
  1220 
  1221 Both use point-free characterization; interpretation proofs may need
  1222 adjustment.  INCOMPATIBILITY.
  1223 
  1224 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
  1225 accordance with standard mathematical terminology. INCOMPATIBILITY.
  1226 
  1227 * Theory Complex_Main: The locale interpretations for the
  1228 bounded_linear and bounded_bilinear locales have been removed, in
  1229 order to reduce the number of duplicate lemmas. Users must use the
  1230 original names for distributivity theorems, potential INCOMPATIBILITY.
  1231 
  1232   divide.add ~> add_divide_distrib
  1233   divide.diff ~> diff_divide_distrib
  1234   divide.setsum ~> setsum_divide_distrib
  1235   mult.add_right ~> right_distrib
  1236   mult.diff_right ~> right_diff_distrib
  1237   mult_right.setsum ~> setsum_right_distrib
  1238   mult_left.diff ~> left_diff_distrib
  1239 
  1240 * Theory Complex_Main: Several redundant theorems have been removed or
  1241 replaced by more general versions. INCOMPATIBILITY.
  1242 
  1243   real_diff_def ~> minus_real_def
  1244   real_divide_def ~> divide_real_def
  1245   real_less_def ~> less_le
  1246   real_abs_def ~> abs_real_def
  1247   real_sgn_def ~> sgn_real_def
  1248   real_mult_commute ~> mult_commute
  1249   real_mult_assoc ~> mult_assoc
  1250   real_mult_1 ~> mult_1_left
  1251   real_add_mult_distrib ~> left_distrib
  1252   real_zero_not_eq_one ~> zero_neq_one
  1253   real_mult_inverse_left ~> left_inverse
  1254   INVERSE_ZERO ~> inverse_zero
  1255   real_le_refl ~> order_refl
  1256   real_le_antisym ~> order_antisym
  1257   real_le_trans ~> order_trans
  1258   real_le_linear ~> linear
  1259   real_le_eq_diff ~> le_iff_diff_le_0
  1260   real_add_left_mono ~> add_left_mono
  1261   real_mult_order ~> mult_pos_pos
  1262   real_mult_less_mono2 ~> mult_strict_left_mono
  1263   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
  1264   real_0_le_divide_iff ~> zero_le_divide_iff
  1265   realpow_two_disj ~> power2_eq_iff
  1266   real_squared_diff_one_factored ~> square_diff_one_factored
  1267   realpow_two_diff ~> square_diff_square_factored
  1268   reals_complete2 ~> complete_real
  1269   real_sum_squared_expand ~> power2_sum
  1270   exp_ln_eq ~> ln_unique
  1271   expi_add ~> exp_add
  1272   expi_zero ~> exp_zero
  1273   lemma_DERIV_subst ~> DERIV_cong
  1274   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
  1275   LIMSEQ_const ~> tendsto_const
  1276   LIMSEQ_norm ~> tendsto_norm
  1277   LIMSEQ_add ~> tendsto_add
  1278   LIMSEQ_minus ~> tendsto_minus
  1279   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
  1280   LIMSEQ_diff ~> tendsto_diff
  1281   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
  1282   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
  1283   LIMSEQ_mult ~> tendsto_mult
  1284   LIMSEQ_inverse ~> tendsto_inverse
  1285   LIMSEQ_divide ~> tendsto_divide
  1286   LIMSEQ_pow ~> tendsto_power
  1287   LIMSEQ_setsum ~> tendsto_setsum
  1288   LIMSEQ_setprod ~> tendsto_setprod
  1289   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
  1290   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
  1291   LIMSEQ_imp_rabs ~> tendsto_rabs
  1292   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
  1293   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
  1294   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
  1295   LIMSEQ_Complex ~> tendsto_Complex
  1296   LIM_ident ~> tendsto_ident_at
  1297   LIM_const ~> tendsto_const
  1298   LIM_add ~> tendsto_add
  1299   LIM_add_zero ~> tendsto_add_zero
  1300   LIM_minus ~> tendsto_minus
  1301   LIM_diff ~> tendsto_diff
  1302   LIM_norm ~> tendsto_norm
  1303   LIM_norm_zero ~> tendsto_norm_zero
  1304   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
  1305   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
  1306   LIM_rabs ~> tendsto_rabs
  1307   LIM_rabs_zero ~> tendsto_rabs_zero
  1308   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
  1309   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
  1310   LIM_compose ~> tendsto_compose
  1311   LIM_mult ~> tendsto_mult
  1312   LIM_scaleR ~> tendsto_scaleR
  1313   LIM_of_real ~> tendsto_of_real
  1314   LIM_power ~> tendsto_power
  1315   LIM_inverse ~> tendsto_inverse
  1316   LIM_sgn ~> tendsto_sgn
  1317   isCont_LIM_compose ~> isCont_tendsto_compose
  1318   bounded_linear.LIM ~> bounded_linear.tendsto
  1319   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
  1320   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
  1321   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
  1322   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
  1323   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
  1324   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
  1325 
  1326 * Theory Complex_Main: The definition of infinite series was
  1327 generalized.  Now it is defined on the type class {topological_space,
  1328 comm_monoid_add}.  Hence it is useable also for extended real numbers.
  1329 
  1330 * Theory Complex_Main: The complex exponential function "expi" is now
  1331 a type-constrained abbreviation for "exp :: complex => complex"; thus
  1332 several polymorphic lemmas about "exp" are now applicable to "expi".
  1333 
  1334 * Code generation:
  1335 
  1336   - Theory Library/Code_Char_ord provides native ordering of
  1337     characters in the target language.
  1338 
  1339   - Commands code_module and code_library are legacy, use export_code
  1340     instead.
  1341 
  1342   - Method "evaluation" is legacy, use method "eval" instead.
  1343 
  1344   - Legacy evaluator "SML" is deactivated by default.  May be
  1345     reactivated by the following theory command:
  1346 
  1347       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
  1348 
  1349 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
  1350 
  1351 * New proof method "induction" that gives induction hypotheses the
  1352 name "IH", thus distinguishing them from further hypotheses that come
  1353 from rule induction.  The latter are still called "hyps".  Method
  1354 "induction" is a thin wrapper around "induct" and follows the same
  1355 syntax.
  1356 
  1357 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
  1358 still available as a legacy feature for some time.
  1359 
  1360 * Nitpick:
  1361   - Added "need" and "total_consts" options.
  1362   - Reintroduced "show_skolems" option by popular demand.
  1363   - Renamed attribute: nitpick_def ~> nitpick_unfold.
  1364     INCOMPATIBILITY.
  1365 
  1366 * Sledgehammer:
  1367   - Use quasi-sound (and efficient) translations by default.
  1368   - Added support for the following provers: E-ToFoF, LEO-II,
  1369     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
  1370   - Automatically preplay and minimize proofs before showing them if
  1371     this can be done within reasonable time.
  1372   - sledgehammer available_provers ~> sledgehammer supported_provers.
  1373     INCOMPATIBILITY.
  1374   - Added "preplay_timeout", "slicing", "type_enc", "sound",
  1375     "max_mono_iters", and "max_new_mono_instances" options.
  1376   - Removed "explicit_apply" and "full_types" options as well as "Full
  1377     Types" Proof General menu item. INCOMPATIBILITY.
  1378 
  1379 * Metis:
  1380   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
  1381   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
  1382     INCOMPATIBILITY.
  1383 
  1384 * Command 'try':
  1385   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
  1386     "elim:" options. INCOMPATIBILITY.
  1387   - Introduced 'try' that not only runs 'try_methods' but also
  1388     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
  1389 
  1390 * Quickcheck:
  1391   - Added "eval" option to evaluate terms for the found counterexample
  1392     (currently only supported by the default (exhaustive) tester).
  1393   - Added post-processing of terms to obtain readable counterexamples
  1394     (currently only supported by the default (exhaustive) tester).
  1395   - New counterexample generator quickcheck[narrowing] enables
  1396     narrowing-based testing.  Requires the Glasgow Haskell compiler
  1397     with its installation location defined in the Isabelle settings
  1398     environment as ISABELLE_GHC.
  1399   - Removed quickcheck tester "SML" based on the SML code generator
  1400     (formly in HOL/Library).
  1401 
  1402 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
  1403 use 'partial_function' instead.
  1404 
  1405 * Theory Library/Extended_Reals replaces now the positive extended
  1406 reals found in probability theory. This file is extended by
  1407 Multivariate_Analysis/Extended_Real_Limits.
  1408 
  1409 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
  1410 from where it must be imported explicitly if it is really required.
  1411 INCOMPATIBILITY.
  1412 
  1413 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
  1414 been moved here.  INCOMPATIBILITY.
  1415 
  1416 * Theory Library/Saturated provides type of numbers with saturated
  1417 arithmetic.
  1418 
  1419 * Theory Library/Product_Lattice defines a pointwise ordering for the
  1420 product type 'a * 'b, and provides instance proofs for various order
  1421 and lattice type classes.
  1422 
  1423 * Theory Library/Countable now provides the "countable_datatype" proof
  1424 method for proving "countable" class instances for datatypes.
  1425 
  1426 * Theory Library/Cset_Monad allows do notation for computable sets
  1427 (cset) via the generic monad ad-hoc overloading facility.
  1428 
  1429 * Library: Theories of common data structures are split into theories
  1430 for implementation, an invariant-ensuring type, and connection to an
  1431 abstract type. INCOMPATIBILITY.
  1432 
  1433   - RBT is split into RBT and RBT_Mapping.
  1434   - AssocList is split and renamed into AList and AList_Mapping.
  1435   - DList is split into DList_Impl, DList, and DList_Cset.
  1436   - Cset is split into Cset and List_Cset.
  1437 
  1438 * Theory Library/Nat_Infinity has been renamed to
  1439 Library/Extended_Nat, with name changes of the following types and
  1440 constants:
  1441 
  1442   type inat   ~> type enat
  1443   Fin         ~> enat
  1444   Infty       ~> infinity (overloaded)
  1445   iSuc        ~> eSuc
  1446   the_Fin     ~> the_enat
  1447 
  1448 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
  1449 been renamed accordingly. INCOMPATIBILITY.
  1450 
  1451 * Session Multivariate_Analysis: The euclidean_space type class now
  1452 fixes a constant "Basis :: 'a set" consisting of the standard
  1453 orthonormal basis for the type. Users now have the option of
  1454 quantifying over this set instead of using the "basis" function, e.g.
  1455 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
  1456 
  1457 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
  1458 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
  1459 "Cart_nth" and "Cart_lambda" have been respectively renamed to
  1460 "vec_nth" and "vec_lambda"; theorems mentioning those names have
  1461 changed to match. Definition theorems for overloaded constants now use
  1462 the standard "foo_vec_def" naming scheme. A few other theorems have
  1463 been renamed as follows (INCOMPATIBILITY):
  1464 
  1465   Cart_eq          ~> vec_eq_iff
  1466   dist_nth_le_cart ~> dist_vec_nth_le
  1467   tendsto_vector   ~> vec_tendstoI
  1468   Cauchy_vector    ~> vec_CauchyI
  1469 
  1470 * Session Multivariate_Analysis: Several duplicate theorems have been
  1471 removed, and other theorems have been renamed or replaced with more
  1472 general versions. INCOMPATIBILITY.
  1473 
  1474   finite_choice ~> finite_set_choice
  1475   eventually_conjI ~> eventually_conj
  1476   eventually_and ~> eventually_conj_iff
  1477   eventually_false ~> eventually_False
  1478   setsum_norm ~> norm_setsum
  1479   Lim_sequentially ~> LIMSEQ_def
  1480   Lim_ident_at ~> LIM_ident
  1481   Lim_const ~> tendsto_const
  1482   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
  1483   Lim_neg ~> tendsto_minus
  1484   Lim_add ~> tendsto_add
  1485   Lim_sub ~> tendsto_diff
  1486   Lim_mul ~> tendsto_scaleR
  1487   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
  1488   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
  1489   Lim_linear ~> bounded_linear.tendsto
  1490   Lim_component ~> tendsto_euclidean_component
  1491   Lim_component_cart ~> tendsto_vec_nth
  1492   Lim_inner ~> tendsto_inner [OF tendsto_const]
  1493   dot_lsum ~> inner_setsum_left
  1494   dot_rsum ~> inner_setsum_right
  1495   continuous_cmul ~> continuous_scaleR [OF continuous_const]
  1496   continuous_neg ~> continuous_minus
  1497   continuous_sub ~> continuous_diff
  1498   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
  1499   continuous_mul ~> continuous_scaleR
  1500   continuous_inv ~> continuous_inverse
  1501   continuous_at_within_inv ~> continuous_at_within_inverse
  1502   continuous_at_inv ~> continuous_at_inverse
  1503   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
  1504   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
  1505   continuous_at_component ~> continuous_component [OF continuous_at_id]
  1506   continuous_on_neg ~> continuous_on_minus
  1507   continuous_on_sub ~> continuous_on_diff
  1508   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
  1509   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
  1510   continuous_on_mul ~> continuous_on_scaleR
  1511   continuous_on_mul_real ~> continuous_on_mult
  1512   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
  1513   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
  1514   continuous_on_inverse ~> continuous_on_inv
  1515   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
  1516   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
  1517   subset_interior ~> interior_mono
  1518   subset_closure ~> closure_mono
  1519   closure_univ ~> closure_UNIV
  1520   real_arch_lt ~> reals_Archimedean2
  1521   real_arch ~> reals_Archimedean3
  1522   real_abs_norm ~> abs_norm_cancel
  1523   real_abs_sub_norm ~> norm_triangle_ineq3
  1524   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
  1525 
  1526 * Session HOL-Probability:
  1527   - Caratheodory's extension lemma is now proved for ring_of_sets.
  1528   - Infinite products of probability measures are now available.
  1529   - Sigma closure is independent, if the generator is independent
  1530   - Use extended reals instead of positive extended
  1531     reals. INCOMPATIBILITY.
  1532 
  1533 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
  1534 
  1535   expand_fun_below ~> fun_below_iff
  1536   below_fun_ext ~> fun_belowI
  1537   expand_cfun_eq ~> cfun_eq_iff
  1538   ext_cfun ~> cfun_eqI
  1539   expand_cfun_below ~> cfun_below_iff
  1540   below_cfun_ext ~> cfun_belowI
  1541   monofun_fun_fun ~> fun_belowD
  1542   monofun_fun_arg ~> monofunE
  1543   monofun_lub_fun ~> adm_monofun [THEN admD]
  1544   cont_lub_fun ~> adm_cont [THEN admD]
  1545   cont2cont_Rep_CFun ~> cont2cont_APP
  1546   cont_Rep_CFun_app ~> cont_APP_app
  1547   cont_Rep_CFun_app_app ~> cont_APP_app_app
  1548   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
  1549   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
  1550   contlub_cfun ~> lub_APP [symmetric]
  1551   contlub_LAM ~> lub_LAM [symmetric]
  1552   thelubI ~> lub_eqI
  1553   UU_I ~> bottomI
  1554   lift_distinct1 ~> lift.distinct(1)
  1555   lift_distinct2 ~> lift.distinct(2)
  1556   Def_not_UU ~> lift.distinct(2)
  1557   Def_inject ~> lift.inject
  1558   below_UU_iff ~> below_bottom_iff
  1559   eq_UU_iff ~> eq_bottom_iff
  1560 
  1561 
  1562 *** Document preparation ***
  1563 
  1564 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
  1565 isar-ref manual, both for description and actual application of the
  1566 same.
  1567 
  1568 * Antiquotation @{value} evaluates the given term and presents its
  1569 result.
  1570 
  1571 * Antiquotations: term style "isub" provides ad-hoc conversion of
  1572 variables x1, y23 into subscripted form x\<^isub>1,
  1573 y\<^isub>2\<^isub>3.
  1574 
  1575 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
  1576 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
  1577 
  1578 * Localized \isabellestyle switch can be used within blocks or groups
  1579 like this:
  1580 
  1581   \isabellestyle{it}  %preferred default
  1582   {\isabellestylett @{text "typewriter stuff"}}
  1583 
  1584 * Discontinued special treatment of hard tabulators.  Implicit
  1585 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
  1586 layouts.
  1587 
  1588 
  1589 *** ML ***
  1590 
  1591 * The inner syntax of sort/type/term/prop supports inlined YXML
  1592 representations within quoted string tokens.  By encoding logical
  1593 entities via Term_XML (in ML or Scala) concrete syntax can be
  1594 bypassed, which is particularly useful for producing bits of text
  1595 under external program control.
  1596 
  1597 * Antiquotations for ML and document preparation are managed as theory
  1598 data, which requires explicit setup.
  1599 
  1600 * Isabelle_Process.is_active allows tools to check if the official
  1601 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
  1602 (better known as Proof General).
  1603 
  1604 * Structure Proof_Context follows standard naming scheme.  Old
  1605 ProofContext is still available for some time as legacy alias.
  1606 
  1607 * Structure Timing provides various operations for timing; supersedes
  1608 former start_timing/end_timing etc.
  1609 
  1610 * Path.print is the official way to show file-system paths to users
  1611 (including quotes etc.).
  1612 
  1613 * Inner syntax: identifiers in parse trees of generic categories
  1614 "logic", "aprop", "idt" etc. carry position information (disguised as
  1615 type constraints).  Occasional INCOMPATIBILITY with non-compliant
  1616 translations that choke on unexpected type constraints.  Positions can
  1617 be stripped in ML translations via Syntax.strip_positions /
  1618 Syntax.strip_positions_ast, or via the syntax constant
  1619 "_strip_positions" within parse trees.  As last resort, positions can
  1620 be disabled via the configuration option Syntax.positions, which is
  1621 called "syntax_positions" in Isar attribute syntax.
  1622 
  1623 * Discontinued special status of various ML structures that contribute
  1624 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
  1625 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
  1626 refer directly to Ast.Constant, Lexicon.is_identifier,
  1627 Syntax_Trans.mk_binder_tr etc.
  1628 
  1629 * Typed print translation: discontinued show_sorts argument, which is
  1630 already available via context of "advanced" translation.
  1631 
  1632 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
  1633 goal states; body tactic needs to address all subgoals uniformly.
  1634 
  1635 * Slightly more special eq_list/eq_set, with shortcut involving
  1636 pointer equality (assumes that eq relation is reflexive).
  1637 
  1638 * Classical tactics use proper Proof.context instead of historic types
  1639 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
  1640 operate directly on Proof.context.  Raw type claset retains its use as
  1641 snapshot of the classical context, which can be recovered via
  1642 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
  1643 INCOMPATIBILITY, classical tactics and derived proof methods require
  1644 proper Proof.context.
  1645 
  1646 
  1647 *** System ***
  1648 
  1649 * Discontinued support for Poly/ML 5.2, which was the last version
  1650 without proper multithreading and TimeLimit implementation.
  1651 
  1652 * Discontinued old lib/scripts/polyml-platform, which has been
  1653 obsolete since Isabelle2009-2.
  1654 
  1655 * Various optional external tools are referenced more robustly and
  1656 uniformly by explicit Isabelle settings as follows:
  1657 
  1658   ISABELLE_CSDP   (formerly CSDP_EXE)
  1659   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  1660   ISABELLE_OCAML  (formerly EXEC_OCAML)
  1661   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  1662   ISABELLE_YAP    (formerly EXEC_YAP)
  1663 
  1664 Note that automated detection from the file-system or search path has
  1665 been discontinued.  INCOMPATIBILITY.
  1666 
  1667 * Scala layer provides JVM method invocation service for static
  1668 methods of type (String)String, see Invoke_Scala.method in ML.  For
  1669 example:
  1670 
  1671   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
  1672 
  1673 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
  1674 this allows to pass structured values between ML and Scala.
  1675 
  1676 * The IsabelleText fonts includes some further glyphs to support the
  1677 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
  1678 installed a local copy (which is normally *not* required) need to
  1679 delete or update it from ~~/lib/fonts/.
  1680 
  1681 
  1682 
  1683 New in Isabelle2011 (January 2011)
  1684 ----------------------------------
  1685 
  1686 *** General ***
  1687 
  1688 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
  1689 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
  1690 useful tooltips and hyperlinks produced from its static analysis.  The
  1691 bundled component provides an executable Isabelle tool that can be run
  1692 like this:
  1693 
  1694   Isabelle2011/bin/isabelle jedit
  1695 
  1696 * Significantly improved Isabelle/Isar implementation manual.
  1697 
  1698 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
  1699 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
  1700 while the default heap location within that directory lacks that extra
  1701 suffix.  This isolates multiple Isabelle installations from each
  1702 other, avoiding problems with old settings in new versions.
  1703 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
  1704 
  1705 * Source files are always encoded as UTF-8, instead of old-fashioned
  1706 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
  1707 the following package declarations:
  1708 
  1709   \usepackage[utf8]{inputenc}
  1710   \usepackage{textcomp}
  1711 
  1712 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
  1713 a Unicode character is treated as a single symbol, not a sequence of
  1714 non-ASCII bytes as before.  Since Isabelle/ML string literals may
  1715 contain symbols without further backslash escapes, Unicode can now be
  1716 used here as well.  Recall that Symbol.explode in ML provides a
  1717 consistent view on symbols, while raw explode (or String.explode)
  1718 merely give a byte-oriented representation.
  1719 
  1720 * Theory loader: source files are primarily located via the master
  1721 directory of each theory node (where the .thy file itself resides).
  1722 The global load path is still partially available as legacy feature.
  1723 Minor INCOMPATIBILITY due to subtle change in file lookup: use
  1724 explicit paths, relatively to the theory.
  1725 
  1726 * Special treatment of ML file names has been discontinued.
  1727 Historically, optional extensions .ML or .sml were added on demand --
  1728 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
  1729 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
  1730 
  1731 * Various options that affect pretty printing etc. are now properly
  1732 handled within the context via configuration options, instead of
  1733 unsynchronized references or print modes.  There are both ML Config.T
  1734 entities and Isar declaration attributes to access these.
  1735 
  1736   ML (Config.T)                 Isar (attribute)
  1737 
  1738   eta_contract                  eta_contract
  1739   show_brackets                 show_brackets
  1740   show_sorts                    show_sorts
  1741   show_types                    show_types
  1742   show_question_marks           show_question_marks
  1743   show_consts                   show_consts
  1744   show_abbrevs                  show_abbrevs
  1745 
  1746   Syntax.ast_trace              syntax_ast_trace
  1747   Syntax.ast_stat               syntax_ast_stat
  1748   Syntax.ambiguity_level        syntax_ambiguity_level
  1749 
  1750   Goal_Display.goals_limit      goals_limit
  1751   Goal_Display.show_main_goal   show_main_goal
  1752 
  1753   Method.rule_trace             rule_trace
  1754 
  1755   Thy_Output.display            thy_output_display
  1756   Thy_Output.quotes             thy_output_quotes
  1757   Thy_Output.indent             thy_output_indent
  1758   Thy_Output.source             thy_output_source
  1759   Thy_Output.break              thy_output_break
  1760 
  1761 Note that corresponding "..._default" references in ML may only be
  1762 changed globally at the ROOT session setup, but *not* within a theory.
  1763 The option "show_abbrevs" supersedes the former print mode
  1764 "no_abbrevs" with inverted meaning.
  1765 
  1766 * More systematic naming of some configuration options.
  1767 INCOMPATIBILITY.
  1768 
  1769   trace_simp  ~>  simp_trace
  1770   debug_simp  ~>  simp_debug
  1771 
  1772 * Support for real valued configuration options, using simplistic
  1773 floating-point notation that coincides with the inner syntax for
  1774 float_token.
  1775 
  1776 * Support for real valued preferences (with approximative PGIP type):
  1777 front-ends need to accept "pgint" values in float notation.
  1778 INCOMPATIBILITY.
  1779 
  1780 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
  1781 DejaVu Sans.
  1782 
  1783 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
  1784 
  1785 
  1786 *** Pure ***
  1787 
  1788 * Command 'type_synonym' (with single argument) replaces somewhat
  1789 outdated 'types', which is still available as legacy feature for some
  1790 time.
  1791 
  1792 * Command 'nonterminal' (with 'and' separated list of arguments)
  1793 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
  1794 
  1795 * Command 'notepad' replaces former 'example_proof' for
  1796 experimentation in Isar without any result.  INCOMPATIBILITY.
  1797 
  1798 * Locale interpretation commands 'interpret' and 'sublocale' accept
  1799 lists of equations to map definitions in a locale to appropriate
  1800 entities in the context of the interpretation.  The 'interpretation'
  1801 command already provided this functionality.
  1802 
  1803 * Diagnostic command 'print_dependencies' prints the locale instances
  1804 that would be activated if the specified expression was interpreted in
  1805 the current context.  Variant "print_dependencies!" assumes a context
  1806 without interpretations.
  1807 
  1808 * Diagnostic command 'print_interps' prints interpretations in proofs
  1809 in addition to interpretations in theories.
  1810 
  1811 * Discontinued obsolete 'global' and 'local' commands to manipulate
  1812 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
  1813 Sign.root_path and Sign.local_path may be applied directly where this
  1814 feature is still required for historical reasons.
  1815 
  1816 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
  1817 'definition' instead.
  1818 
  1819 * The "prems" fact, which refers to the accidental collection of
  1820 foundational premises in the context, is now explicitly marked as
  1821 legacy feature and will be discontinued soon.  Consider using "assms"
  1822 of the head statement or reference facts by explicit names.
  1823 
  1824 * Document antiquotations @{class} and @{type} print classes and type
  1825 constructors.
  1826 
  1827 * Document antiquotation @{file} checks file/directory entries within
  1828 the local file system.
  1829 
  1830 
  1831 *** HOL ***
  1832 
  1833 * Coercive subtyping: functions can be declared as coercions and type
  1834 inference will add them as necessary upon input of a term.  Theory
  1835 Complex_Main declares real :: nat => real and real :: int => real as
  1836 coercions. A coercion function f is declared like this:
  1837 
  1838   declare [[coercion f]]
  1839 
  1840 To lift coercions through type constructors (e.g. from nat => real to
  1841 nat list => real list), map functions can be declared, e.g.
  1842 
  1843   declare [[coercion_map map]]
  1844 
  1845 Currently coercion inference is activated only in theories including
  1846 real numbers, i.e. descendants of Complex_Main.  This is controlled by
  1847 the configuration option "coercion_enabled", e.g. it can be enabled in
  1848 other theories like this:
  1849 
  1850   declare [[coercion_enabled]]
  1851 
  1852 * Command 'partial_function' provides basic support for recursive
  1853 function definitions over complete partial orders.  Concrete instances
  1854 are provided for i) the option type, ii) tail recursion on arbitrary
  1855 types, and iii) the heap monad of Imperative_HOL.  See
  1856 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1857 for examples.
  1858 
  1859 * Function package: f.psimps rules are no longer implicitly declared
  1860 as [simp].  INCOMPATIBILITY.
  1861 
  1862 * Datatype package: theorems generated for executable equality (class
  1863 "eq") carry proper names and are treated as default code equations.
  1864 
  1865 * Inductive package: now offers command 'inductive_simps' to
  1866 automatically derive instantiated and simplified equations for
  1867 inductive predicates, similar to 'inductive_cases'.
  1868 
  1869 * Command 'enriched_type' allows to register properties of the
  1870 functorial structure of types.
  1871 
  1872 * Improved infrastructure for term evaluation using code generator
  1873 techniques, in particular static evaluation conversions.
  1874 
  1875 * Code generator: Scala (2.8 or higher) has been added to the target
  1876 languages.
  1877 
  1878 * Code generator: globbing constant expressions "*" and "Theory.*"
  1879 have been replaced by the more idiomatic "_" and "Theory._".
  1880 INCOMPATIBILITY.
  1881 
  1882 * Code generator: export_code without explicit file declaration prints
  1883 to standard output.  INCOMPATIBILITY.
  1884 
  1885 * Code generator: do not print function definitions for case
  1886 combinators any longer.
  1887 
  1888 * Code generator: simplification with rules determined with
  1889 src/Tools/Code/code_simp.ML and method "code_simp".
  1890 
  1891 * Code generator for records: more idiomatic representation of record
  1892 types.  Warning: records are not covered by ancient SML code
  1893 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1894 rep_datatype declaration helps to succeed then:
  1895 
  1896   record 'a foo = ...
  1897   ...
  1898   rep_datatype foo_ext ...
  1899 
  1900 * Records: logical foundation type for records does not carry a
  1901 '_type' suffix any longer (obsolete due to authentic syntax).
  1902 INCOMPATIBILITY.
  1903 
  1904 * Quickcheck now by default uses exhaustive testing instead of random
  1905 testing.  Random testing can be invoked by "quickcheck [random]",
  1906 exhaustive testing by "quickcheck [exhaustive]".
  1907 
  1908 * Quickcheck instantiates polymorphic types with small finite
  1909 datatypes by default. This enables a simple execution mechanism to
  1910 handle quantifiers and function equality over the finite datatypes.
  1911 
  1912 * Quickcheck random generator has been renamed from "code" to
  1913 "random".  INCOMPATIBILITY.
  1914 
  1915 * Quickcheck now has a configurable time limit which is set to 30
  1916 seconds by default. This can be changed by adding [timeout = n] to the
  1917 quickcheck command. The time limit for Auto Quickcheck is still set
  1918 independently.
  1919 
  1920 * Quickcheck in locales considers interpretations of that locale for
  1921 counter example search.
  1922 
  1923 * Sledgehammer:
  1924   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1925     method. See the Sledgehammer manual for details ("isabelle doc
  1926     sledgehammer").
  1927   - Renamed commands:
  1928     sledgehammer atp_info ~> sledgehammer running_provers
  1929     sledgehammer atp_kill ~> sledgehammer kill_provers
  1930     sledgehammer available_atps ~> sledgehammer available_provers
  1931     INCOMPATIBILITY.
  1932   - Renamed options:
  1933     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1934     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1935     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1936     (and "ms" and "min" are no longer supported)
  1937     INCOMPATIBILITY.
  1938 
  1939 * Nitpick:
  1940   - Renamed options:
  1941     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1942     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1943     INCOMPATIBILITY.
  1944   - Added support for partial quotient types.
  1945   - Added local versions of the "Nitpick.register_xxx" functions.
  1946   - Added "whack" option.
  1947   - Allow registration of quotient types as codatatypes.
  1948   - Improved "merge_type_vars" option to merge more types.
  1949   - Removed unsound "fast_descrs" option.
  1950   - Added custom symmetry breaking for datatypes, making it possible to reach
  1951     higher cardinalities.
  1952   - Prevent the expansion of too large definitions.
  1953 
  1954 * Proof methods "metis" and "meson" now have configuration options
  1955 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1956 to diagnose these tools. E.g.
  1957 
  1958     using [[metis_trace = true]]
  1959 
  1960 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1961 manually as command 'solve_direct'.
  1962 
  1963 * The default SMT solver Z3 must be enabled explicitly (due to
  1964 licensing issues) by setting the environment variable
  1965 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1966 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1967 changing the SMT solver is done via the configuration option
  1968 "smt_solver".
  1969 
  1970 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1971 i.e. "remote_cvc3" and "remote_z3".
  1972 
  1973 * Added basic SMT support for datatypes, records, and typedefs using
  1974 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1975 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1976 support for a similar behavior).  Minor INCOMPATIBILITY.
  1977 
  1978 * Changed SMT configuration options:
  1979   - Renamed:
  1980     z3_proofs ~> smt_oracle (with inverted meaning)
  1981     z3_trace_assms ~> smt_trace_used_facts
  1982     INCOMPATIBILITY.
  1983   - Added:
  1984     smt_verbose
  1985     smt_random_seed
  1986     smt_datatypes
  1987     smt_infer_triggers
  1988     smt_monomorph_limit
  1989     cvc3_options
  1990     remote_cvc3_options
  1991     remote_z3_options
  1992     yices_options
  1993 
  1994 * Boogie output files (.b2i files) need to be declared in the theory
  1995 header.
  1996 
  1997 * Simplification procedure "list_to_set_comprehension" rewrites list
  1998 comprehensions applied to List.set to set comprehensions.  Occasional
  1999 INCOMPATIBILITY, may be deactivated like this:
  2000 
  2001   declare [[simproc del: list_to_set_comprehension]]
  2002 
  2003 * Removed old version of primrec package.  INCOMPATIBILITY.
  2004 
  2005 * Removed simplifier congruence rule of "prod_case", as has for long
  2006 been the case with "split".  INCOMPATIBILITY.
  2007 
  2008 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  2009 
  2010 * Removed [split_format ... and ... and ...] version of
  2011 [split_format].  Potential INCOMPATIBILITY.
  2012 
  2013 * Predicate "sorted" now defined inductively, with nice induction
  2014 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  2015 
  2016 * Constant "contents" renamed to "the_elem", to free the generic name
  2017 contents for other uses.  INCOMPATIBILITY.
  2018 
  2019 * Renamed class eq and constant eq (for code generation) to class
  2020 equal and constant equal, plus renaming of related facts and various
  2021 tuning.  INCOMPATIBILITY.
  2022 
  2023 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  2024 
  2025 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  2026 INCOMPATIBILITY.
  2027 
  2028 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  2029 avoid confusion with finite sets.  INCOMPATIBILITY.
  2030 
  2031 * Abandoned locales equiv, congruent and congruent2 for equivalence
  2032 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  2033 for congruent(2)).
  2034 
  2035 * Some previously unqualified names have been qualified:
  2036 
  2037   types
  2038     bool ~> HOL.bool
  2039     nat ~> Nat.nat
  2040 
  2041   constants
  2042     Trueprop ~> HOL.Trueprop
  2043     True ~> HOL.True
  2044     False ~> HOL.False
  2045     op & ~> HOL.conj
  2046     op | ~> HOL.disj
  2047     op --> ~> HOL.implies
  2048     op = ~> HOL.eq
  2049     Not ~> HOL.Not
  2050     The ~> HOL.The
  2051     All ~> HOL.All
  2052     Ex ~> HOL.Ex
  2053     Ex1 ~> HOL.Ex1
  2054     Let ~> HOL.Let
  2055     If ~> HOL.If
  2056     Ball ~> Set.Ball
  2057     Bex ~> Set.Bex
  2058     Suc ~> Nat.Suc
  2059     Pair ~> Product_Type.Pair
  2060     fst ~> Product_Type.fst
  2061     snd ~> Product_Type.snd
  2062     curry ~> Product_Type.curry
  2063     op : ~> Set.member
  2064     Collect ~> Set.Collect
  2065 
  2066 INCOMPATIBILITY.
  2067 
  2068 * More canonical naming convention for some fundamental definitions:
  2069 
  2070     bot_bool_eq ~> bot_bool_def
  2071     top_bool_eq ~> top_bool_def
  2072     inf_bool_eq ~> inf_bool_def
  2073     sup_bool_eq ~> sup_bool_def
  2074     bot_fun_eq  ~> bot_fun_def
  2075     top_fun_eq  ~> top_fun_def
  2076     inf_fun_eq  ~> inf_fun_def
  2077     sup_fun_eq  ~> sup_fun_def
  2078 
  2079 INCOMPATIBILITY.
  2080 
  2081 * More stylized fact names:
  2082 
  2083   expand_fun_eq ~> fun_eq_iff
  2084   expand_set_eq ~> set_eq_iff
  2085   set_ext       ~> set_eqI
  2086   nat_number    ~> eval_nat_numeral
  2087 
  2088 INCOMPATIBILITY.
  2089 
  2090 * Refactoring of code-generation specific operations in theory List:
  2091 
  2092   constants
  2093     null ~> List.null
  2094 
  2095   facts
  2096     mem_iff ~> member_def
  2097     null_empty ~> null_def
  2098 
  2099 INCOMPATIBILITY.  Note that these were not supposed to be used
  2100 regularly unless for striking reasons; their main purpose was code
  2101 generation.
  2102 
  2103 Various operations from the Haskell prelude are used for generating
  2104 Haskell code.
  2105 
  2106 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  2107 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  2108 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  2109 
  2110 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  2111 "*" and "+" respectively.  INCOMPATIBILITY.
  2112 
  2113 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  2114 "Sum_Type.Plus" instead.
  2115 
  2116 * Constant "split" has been merged with constant "prod_case"; names of
  2117 ML functions, facts etc. involving split have been retained so far,
  2118 though.  INCOMPATIBILITY.
  2119 
  2120 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  2121 instead.  INCOMPATIBILITY.
  2122 
  2123 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  2124 INCOMPATIBILITY.
  2125 
  2126 * Former theory Library/Enum is now part of the HOL-Main image.
  2127 INCOMPATIBILITY: all constants of the Enum theory now have to be
  2128 referred to by its qualified name.
  2129 
  2130   enum    ~>  Enum.enum
  2131   nlists  ~>  Enum.nlists
  2132   product ~>  Enum.product
  2133 
  2134 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  2135 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  2136 INCOMPATIBILITY.
  2137 
  2138 * Theory Library/SetsAndFunctions has been split into
  2139 Library/Function_Algebras and Library/Set_Algebras; canonical names
  2140 for instance definitions for functions; various improvements.
  2141 INCOMPATIBILITY.
  2142 
  2143 * Theory Library/Multiset provides stable quicksort implementation of
  2144 sort_key.
  2145 
  2146 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  2147 INCOMPATIBILITY.
  2148 
  2149 * Session Multivariate_Analysis: introduced a type class for euclidean
  2150 space.  Most theorems are now stated in terms of euclidean spaces
  2151 instead of finite cartesian products.
  2152 
  2153   types
  2154     real ^ 'n ~>  'a::real_vector
  2155               ~>  'a::euclidean_space
  2156               ~>  'a::ordered_euclidean_space
  2157         (depends on your needs)
  2158 
  2159   constants
  2160      _ $ _        ~> _ $$ _
  2161      \<chi> x. _  ~> \<chi>\<chi> x. _
  2162      CARD('n)     ~> DIM('a)
  2163 
  2164 Also note that the indices are now natural numbers and not from some
  2165 finite type. Finite cartesian products of euclidean spaces, products
  2166 of euclidean spaces the real and complex numbers are instantiated to
  2167 be euclidean_spaces.  INCOMPATIBILITY.
  2168 
  2169 * Session Probability: introduced pextreal as positive extended real
  2170 numbers.  Use pextreal as value for measures.  Introduce the
  2171 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  2172 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  2173 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  2174 
  2175 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  2176 INCOMPATIBILITY.
  2177 
  2178 * Session SPARK (with image HOL-SPARK) provides commands to load and
  2179 prove verification conditions generated by the SPARK Ada program
  2180 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  2181 
  2182 
  2183 *** HOL-Algebra ***
  2184 
  2185 * Theorems for additive ring operations (locale abelian_monoid and
  2186 descendants) are generated by interpretation from their multiplicative
  2187 counterparts.  Names (in particular theorem names) have the mandatory
  2188 qualifier 'add'.  Previous theorem names are redeclared for
  2189 compatibility.
  2190 
  2191 * Structure "int_ring" is now an abbreviation (previously a
  2192 definition).  This fits more natural with advanced interpretations.
  2193 
  2194 
  2195 *** HOLCF ***
  2196 
  2197 * The domain package now runs in definitional mode by default: The
  2198 former command 'new_domain' is now called 'domain'.  To use the domain
  2199 package in its original axiomatic mode, use 'domain (unsafe)'.
  2200 INCOMPATIBILITY.
  2201 
  2202 * The new class "domain" is now the default sort.  Class "predomain"
  2203 is an unpointed version of "domain". Theories can be updated by
  2204 replacing sort annotations as shown below.  INCOMPATIBILITY.
  2205 
  2206   'a::type ~> 'a::countable
  2207   'a::cpo  ~> 'a::predomain
  2208   'a::pcpo ~> 'a::domain
  2209 
  2210 * The old type class "rep" has been superseded by class "domain".
  2211 Accordingly, users of the definitional package must remove any
  2212 "default_sort rep" declarations.  INCOMPATIBILITY.
  2213 
  2214 * The domain package (definitional mode) now supports unpointed
  2215 predomain argument types, as long as they are marked 'lazy'. (Strict
  2216 arguments must be in class "domain".) For example, the following
  2217 domain definition now works:
  2218 
  2219   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  2220 
  2221 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  2222 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  2223 'a option, and 'a list.  Additionally, it configures fixrec and the
  2224 domain package to work with these types.  For example:
  2225 
  2226   fixrec isInl :: "('a + 'b) u -> tr"
  2227     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  2228 
  2229   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  2230 
  2231 * The "(permissive)" option of fixrec has been replaced with a
  2232 per-equation "(unchecked)" option. See
  2233 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  2234 
  2235 * The "bifinite" class no longer fixes a constant "approx"; the class
  2236 now just asserts that such a function exists.  INCOMPATIBILITY.
  2237 
  2238 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  2239 defines an embedding of type 'a defl into udom by default; instances
  2240 of "bifinite" and "domain" classes are available in
  2241 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  2242 
  2243 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  2244 
  2245 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  2246 
  2247 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  2248 
  2249 * The function "cprod_map" has been renamed to "prod_map".
  2250 INCOMPATIBILITY.
  2251 
  2252 * The monadic bind operator on each powerdomain has new binder syntax
  2253 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  2254 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  2255 
  2256 * The infix syntax for binary union on each powerdomain has changed
  2257 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  2258 syntax.  INCOMPATIBILITY.
  2259 
  2260 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  2261 still supported as an input translation.
  2262 
  2263 * Renamed some theorems (the original names are also still available).
  2264 
  2265   expand_fun_below   ~> fun_below_iff
  2266   below_fun_ext      ~> fun_belowI
  2267   expand_cfun_eq     ~> cfun_eq_iff
  2268   ext_cfun           ~> cfun_eqI
  2269   expand_cfun_below  ~> cfun_below_iff
  2270   below_cfun_ext     ~> cfun_belowI
  2271   cont2cont_Rep_CFun ~> cont2cont_APP
  2272 
  2273 * The Abs and Rep functions for various types have changed names.
  2274 Related theorem names have also changed to match. INCOMPATIBILITY.
  2275 
  2276   Rep_CFun  ~> Rep_cfun
  2277   Abs_CFun  ~> Abs_cfun
  2278   Rep_Sprod ~> Rep_sprod
  2279   Abs_Sprod ~> Abs_sprod
  2280   Rep_Ssum  ~> Rep_ssum
  2281   Abs_Ssum  ~> Abs_ssum
  2282 
  2283 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  2284 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  2285 
  2286 * Various changes to bisimulation/coinduction with domain package:
  2287 
  2288   - Definitions of "bisim" constants no longer mention definedness.
  2289   - With mutual recursion, "bisim" predicate is now curried.
  2290   - With mutual recursion, each type gets a separate coind theorem.
  2291   - Variable names in bisim_def and coinduct rules have changed.
  2292 
  2293 INCOMPATIBILITY.
  2294 
  2295 * Case combinators generated by the domain package for type "foo" are
  2296 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  2297 
  2298 * Several theorems have been renamed to more accurately reflect the
  2299 names of constants and types involved.  INCOMPATIBILITY.
  2300 
  2301   thelub_const    ~> lub_const
  2302   lub_const       ~> is_lub_const
  2303   thelubI         ~> lub_eqI
  2304   is_lub_lub      ~> is_lubD2
  2305   lubI            ~> is_lub_lub
  2306   unique_lub      ~> is_lub_unique
  2307   is_ub_lub       ~> is_lub_rangeD1
  2308   lub_bin_chain   ~> is_lub_bin_chain
  2309   lub_fun         ~> is_lub_fun
  2310   thelub_fun      ~> lub_fun
  2311   thelub_cfun     ~> lub_cfun
  2312   thelub_Pair     ~> lub_Pair
  2313   lub_cprod       ~> is_lub_prod
  2314   thelub_cprod    ~> lub_prod
  2315   minimal_cprod   ~> minimal_prod
  2316   inst_cprod_pcpo ~> inst_prod_pcpo
  2317   UU_I            ~> bottomI
  2318   compact_UU      ~> compact_bottom
  2319   deflation_UU    ~> deflation_bottom
  2320   finite_deflation_UU ~> finite_deflation_bottom
  2321 
  2322 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  2323 
  2324   sq_ord_less_eq_trans ~> below_eq_trans
  2325   sq_ord_eq_less_trans ~> eq_below_trans
  2326   refl_less            ~> below_refl
  2327   trans_less           ~> below_trans
  2328   antisym_less         ~> below_antisym
  2329   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  2330   box_less             ~> box_below
  2331   rev_trans_less       ~> rev_below_trans
  2332   not_less2not_eq      ~> not_below2not_eq
  2333   less_UU_iff          ~> below_UU_iff
  2334   flat_less_iff        ~> flat_below_iff
  2335   adm_less             ~> adm_below
  2336   adm_not_less         ~> adm_not_below
  2337   adm_compact_not_less ~> adm_compact_not_below
  2338   less_fun_def         ~> below_fun_def
  2339   expand_fun_less      ~> fun_below_iff
  2340   less_fun_ext         ~> fun_belowI
  2341   less_discr_def       ~> below_discr_def
  2342   discr_less_eq        ~> discr_below_eq
  2343   less_unit_def        ~> below_unit_def
  2344   less_cprod_def       ~> below_prod_def
  2345   prod_lessI           ~> prod_belowI
  2346   Pair_less_iff        ~> Pair_below_iff
  2347   fst_less_iff         ~> fst_below_iff
  2348   snd_less_iff         ~> snd_below_iff
  2349   expand_cfun_less     ~> cfun_below_iff
  2350   less_cfun_ext        ~> cfun_belowI
  2351   injection_less       ~> injection_below
  2352   less_up_def          ~> below_up_def
  2353   not_Iup_less         ~> not_Iup_below
  2354   Iup_less             ~> Iup_below
  2355   up_less              ~> up_below
  2356   Def_inject_less_eq   ~> Def_below_Def
  2357   Def_less_is_eq       ~> Def_below_iff
  2358   spair_less_iff       ~> spair_below_iff
  2359   less_sprod           ~> below_sprod
  2360   spair_less           ~> spair_below
  2361   sfst_less_iff        ~> sfst_below_iff
  2362   ssnd_less_iff        ~> ssnd_below_iff
  2363   fix_least_less       ~> fix_least_below
  2364   dist_less_one        ~> dist_below_one
  2365   less_ONE             ~> below_ONE
  2366   ONE_less_iff         ~> ONE_below_iff
  2367   less_sinlD           ~> below_sinlD
  2368   less_sinrD           ~> below_sinrD
  2369 
  2370 
  2371 *** FOL and ZF ***
  2372 
  2373 * All constant names are now qualified internally and use proper
  2374 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  2375 
  2376 
  2377 *** ML ***
  2378 
  2379 * Antiquotation @{assert} inlines a function bool -> unit that raises
  2380 Fail if the argument is false.  Due to inlining the source position of
  2381 failed assertions is included in the error output.
  2382 
  2383 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  2384 text is in practice always evaluated with a stable theory checkpoint.
  2385 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  2386 
  2387 * Antiquotation @{theory A} refers to theory A from the ancestry of
  2388 the current context, not any accidental theory loader state as before.
  2389 Potential INCOMPATIBILITY, subtle change in semantics.
  2390 
  2391 * Syntax.pretty_priority (default 0) configures the required priority
  2392 of pretty-printed output and thus affects insertion of parentheses.
  2393 
  2394 * Syntax.default_root (default "any") configures the inner syntax
  2395 category (nonterminal symbol) for parsing of terms.
  2396 
  2397 * Former exception Library.UnequalLengths now coincides with
  2398 ListPair.UnequalLengths.
  2399 
  2400 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  2401 main functionality is provided by structure Simplifier.
  2402 
  2403 * Renamed raw "explode" function to "raw_explode" to emphasize its
  2404 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  2405 almost all situations.
  2406 
  2407 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  2408 See implementation manual for further details on exceptions in
  2409 Isabelle/ML.
  2410 
  2411 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  2412 meaning.
  2413 
  2414 * Renamed structure PureThy to Pure_Thy and moved most of its
  2415 operations to structure Global_Theory, to emphasize that this is
  2416 rarely-used global-only stuff.
  2417 
  2418 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  2419 instead (or tracing for high-volume output).
  2420 
  2421 * Configuration option show_question_marks only affects regular pretty
  2422 printing of types and terms, not raw Term.string_of_vname.
  2423 
  2424 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  2425 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  2426 @{thms} for most purposes.
  2427 
  2428 * ML structure Unsynchronized is never opened, not even in Isar
  2429 interaction mode as before.  Old Unsynchronized.set etc. have been
  2430 discontinued -- use plain := instead.  This should be *rare* anyway,
  2431 since modern tools always work via official context data, notably
  2432 configuration options.
  2433 
  2434 * Parallel and asynchronous execution requires special care concerning
  2435 interrupts.  Structure Exn provides some convenience functions that
  2436 avoid working directly with raw Interrupt.  User code must not absorb
  2437 interrupts -- intermediate handling (for cleanup etc.) needs to be
  2438 followed by re-raising of the original exception.  Another common
  2439 source of mistakes are "handle _" patterns, which make the meaning of
  2440 the program subject to physical effects of the environment.
  2441 
  2442 
  2443 
  2444 New in Isabelle2009-2 (June 2010)
  2445 ---------------------------------
  2446 
  2447 *** General ***
  2448 
  2449 * Authentic syntax for *all* logical entities (type classes, type
  2450 constructors, term constants): provides simple and robust
  2451 correspondence between formal entities and concrete syntax.  Within
  2452 the parse tree / AST representations, "constants" are decorated by
  2453 their category (class, type, const) and spelled out explicitly with
  2454 their full internal name.
  2455 
  2456 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  2457 and translations (translation rules and translation functions in ML).
  2458 Some hints on upgrading:
  2459 
  2460   - Many existing uses of 'syntax' and 'translations' can be replaced
  2461     by more modern 'type_notation', 'notation' and 'abbreviation',
  2462     which are independent of this issue.
  2463 
  2464   - 'translations' require markup within the AST; the term syntax
  2465     provides the following special forms:
  2466 
  2467       CONST c   -- produces syntax version of constant c from context
  2468       XCONST c  -- literally c, checked as constant from context
  2469       c         -- literally c, if declared by 'syntax'
  2470 
  2471     Plain identifiers are treated as AST variables -- occasionally the
  2472     system indicates accidental variables via the error "rhs contains
  2473     extra variables".
  2474 
  2475     Type classes and type constructors are marked according to their
  2476     concrete syntax.  Some old translations rules need to be written
  2477     for the "type" category, using type constructor application
  2478     instead of pseudo-term application of the default category
  2479     "logic".
  2480 
  2481   - 'parse_translation' etc. in ML may use the following
  2482     antiquotations:
  2483 
  2484       @{class_syntax c}   -- type class c within parse tree / AST
  2485       @{term_syntax c}    -- type constructor c within parse tree / AST
  2486       @{const_syntax c}   -- ML version of "CONST c" above
  2487       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  2488 
  2489   - Literal types within 'typed_print_translations', i.e. those *not*
  2490     represented as pseudo-terms are represented verbatim.  Use @{class
  2491     c} or @{type_name c} here instead of the above syntax
  2492     antiquotations.
  2493 
  2494 Note that old non-authentic syntax was based on unqualified base
  2495 names, so all of the above "constant" names would coincide.  Recall
  2496 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  2497 diagnose syntax problems.
  2498 
  2499 * Type constructors admit general mixfix syntax, not just infix.
  2500 
  2501 * Concrete syntax may be attached to local entities without a proof
  2502 body, too.  This works via regular mixfix annotations for 'fix',
  2503 'def', 'obtain' etc. or via the explicit 'write' command, which is
  2504 similar to the 'notation' command in theory specifications.
  2505 
  2506 * Discontinued unnamed infix syntax (legacy feature for many years) --
  2507 need to specify constant name and syntax separately.  Internal ML
  2508 datatype constructors have been renamed from InfixName to Infix etc.
  2509 Minor INCOMPATIBILITY.
  2510 
  2511 * Schematic theorem statements need to be explicitly markup as such,
  2512 via commands 'schematic_lemma', 'schematic_theorem',
  2513 'schematic_corollary'.  Thus the relevance of the proof is made
  2514 syntactically clear, which impacts performance in a parallel or
  2515 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  2516 
  2517 * Use of cumulative prems via "!" in some proof methods has been
  2518 discontinued (old legacy feature).
  2519 
  2520 * References 'trace_simp' and 'debug_simp' have been replaced by
  2521 configuration options stored in the context. Enabling tracing (the
  2522 case of debugging is similar) in proofs works via
  2523 
  2524   using [[trace_simp = true]]
  2525 
  2526 Tracing is then active for all invocations of the simplifier in
  2527 subsequent goal refinement steps. Tracing may also still be enabled or
  2528 disabled via the ProofGeneral settings menu.
  2529 
  2530 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  2531 'hide_fact' replace the former 'hide' KIND command.  Minor
  2532 INCOMPATIBILITY.
  2533 
  2534 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  2535 more efficient than combinations with -q1 or -q2.
  2536 
  2537 
  2538 *** Pure ***
  2539 
  2540 * Proofterms record type-class reasoning explicitly, using the
  2541 "unconstrain" operation internally.  This eliminates all sort
  2542 constraints from a theorem and proof, introducing explicit
  2543 OFCLASS-premises.  On the proof term level, this operation is
  2544 automatically applied at theorem boundaries, such that closed proofs
  2545 are always free of sort constraints.  INCOMPATIBILITY for tools that
  2546 inspect proof terms.
  2547 
  2548 * Local theory specifications may depend on extra type variables that
  2549 are not present in the result type -- arguments TYPE('a) :: 'a itself
  2550 are added internally.  For example:
  2551 
  2552   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  2553 
  2554 * Predicates of locales introduced by classes carry a mandatory
  2555 "class" prefix.  INCOMPATIBILITY.
  2556 
  2557 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  2558 
  2559 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  2560 'class' instead.
  2561 
  2562 * Command 'code_reflect' allows to incorporate generated ML code into
  2563 runtime environment; replaces immature code_datatype antiquotation.
  2564 INCOMPATIBILITY.
  2565 
  2566 * Code generator: simple concept for abstract datatypes obeying
  2567 invariants.
  2568 
  2569 * Code generator: details of internal data cache have no impact on the
  2570 user space functionality any longer.
  2571 
  2572 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  2573 subgoals.  This is more appropriate for interpretations with 'where'.
  2574 INCOMPATIBILITY.
  2575 
  2576 * Command 'example_proof' opens an empty proof body.  This allows to
  2577 experiment with Isar, without producing any persistent result.
  2578 
  2579 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  2580 within a local theory context, with explicit checking of the
  2581 constructors involved (in contrast to the raw 'syntax' versions).
  2582 
  2583 * Commands 'types' and 'typedecl' now work within a local theory
  2584 context -- without introducing dependencies on parameters or
  2585 assumptions, which is not possible in Isabelle/Pure.
  2586 
  2587 * Command 'defaultsort' has been renamed to 'default_sort', it works
  2588 within a local theory context.  Minor INCOMPATIBILITY.
  2589 
  2590 
  2591 *** HOL ***
  2592 
  2593 * Command 'typedef' now works within a local theory context -- without
  2594 introducing dependencies on parameters or assumptions, which is not
  2595 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  2596 contain multiple interpretations of local typedefs (with different
  2597 non-emptiness proofs), even in a global theory context.
  2598 
  2599 * New package for quotient types.  Commands 'quotient_type' and
  2600 'quotient_definition' may be used for defining types and constants by
  2601 quotient constructions.  An example is the type of integers created by
  2602 quotienting pairs of natural numbers:
  2603 
  2604   fun
  2605     intrel :: "(nat * nat) => (nat * nat) => bool"
  2606   where
  2607     "intrel (x, y) (u, v) = (x + v = u + y)"
  2608 
  2609   quotient_type int = "nat * nat" / intrel
  2610     by (auto simp add: equivp_def expand_fun_eq)
  2611 
  2612   quotient_definition
  2613     "0::int" is "(0::nat, 0::nat)"
  2614 
  2615 The method "lifting" can be used to lift of theorems from the
  2616 underlying "raw" type to the quotient type.  The example
  2617 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  2618 construction and provides a reasoning infrastructure for finite sets.
  2619 
  2620 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  2621 clash with new theory Quotient in Main HOL.
  2622 
  2623 * Moved the SMT binding into the main HOL session, eliminating
  2624 separate HOL-SMT session.
  2625 
  2626 * List membership infix mem operation is only an input abbreviation.
  2627 INCOMPATIBILITY.
  2628 
  2629 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  2630 for future developements; former Library/Word.thy is still present in
  2631 the AFP entry RSAPPS.
  2632 
  2633 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  2634 longer shadowed.  INCOMPATIBILITY.
  2635 
  2636 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  2637 INCOMPATIBILITY.
  2638 
  2639 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  2640 INCOMPATIBILITY.
  2641 
  2642 * Dropped normalizing_semiring etc; use the facts in semiring classes
  2643 instead.  INCOMPATIBILITY.
  2644 
  2645 * Dropped several real-specific versions of lemmas about floor and
  2646 ceiling; use the generic lemmas from theory "Archimedean_Field"
  2647 instead.  INCOMPATIBILITY.
  2648 
  2649   floor_number_of_eq         ~> floor_number_of
  2650   le_floor_eq_number_of      ~> number_of_le_floor
  2651   le_floor_eq_zero           ~> zero_le_floor
  2652   le_floor_eq_one            ~> one_le_floor
  2653   floor_less_eq_number_of    ~> floor_less_number_of
  2654   floor_less_eq_zero         ~> floor_less_zero
  2655   floor_less_eq_one          ~> floor_less_one
  2656   less_floor_eq_number_of    ~> number_of_less_floor
  2657   less_floor_eq_zero         ~> zero_less_floor
  2658   less_floor_eq_one          ~> one_less_floor
  2659   floor_le_eq_number_of      ~> floor_le_number_of
  2660   floor_le_eq_zero           ~> floor_le_zero
  2661   floor_le_eq_one            ~> floor_le_one
  2662   floor_subtract_number_of   ~> floor_diff_number_of
  2663   floor_subtract_one         ~> floor_diff_one
  2664   ceiling_number_of_eq       ~> ceiling_number_of
  2665   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  2666   ceiling_le_zero_eq         ~> ceiling_le_zero
  2667   ceiling_le_eq_one          ~> ceiling_le_one
  2668   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  2669   less_ceiling_eq_zero       ~> zero_less_ceiling
  2670   less_ceiling_eq_one        ~> one_less_ceiling
  2671   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  2672   ceiling_less_eq_zero       ~> ceiling_less_zero
  2673   ceiling_less_eq_one        ~> ceiling_less_one
  2674   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  2675   le_ceiling_eq_zero         ~> zero_le_ceiling
  2676   le_ceiling_eq_one          ~> one_le_ceiling
  2677   ceiling_subtract_number_of ~> ceiling_diff_number_of
  2678   ceiling_subtract_one       ~> ceiling_diff_one
  2679 
  2680 * Theory "Finite_Set": various folding_XXX locales facilitate the
  2681 application of the various fold combinators on finite sets.
  2682 
  2683 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  2684 provides abstract red-black tree type which is backed by "RBT_Impl" as
  2685 implementation.  INCOMPATIBILTY.
  2686 
  2687 * Theory Library/Coinductive_List has been removed -- superseded by
  2688 AFP/thys/Coinductive.
  2689 
  2690 * Theory PReal, including the type "preal" and related operations, has
  2691 been removed.  INCOMPATIBILITY.
  2692 
  2693 * Real: new development using Cauchy Sequences.
  2694 
  2695 * Split off theory "Big_Operators" containing setsum, setprod,
  2696 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  2697 
  2698 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  2699 "Int" etc.  INCOMPATIBILITY.
  2700 
  2701 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  2702 
  2703 * New set of rules "ac_simps" provides combined assoc / commute
  2704 rewrites for all interpretations of the appropriate generic locales.
  2705 
  2706 * Renamed theory "OrderedGroup" to "Groups" and split theory
  2707 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  2708 appropriate and more consistent names suitable for name prefixes
  2709 within the HOL theories.  INCOMPATIBILITY.
  2710 
  2711 * Some generic constants have been put to appropriate theories:
  2712   - less_eq, less: Orderings
  2713   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  2714   - inverse, divide: Rings
  2715 INCOMPATIBILITY.
  2716 
  2717 * More consistent naming of type classes involving orderings (and
  2718 lattices):
  2719 
  2720     lower_semilattice                   ~> semilattice_inf
  2721     upper_semilattice                   ~> semilattice_sup
  2722 
  2723     dense_linear_order                  ~> dense_linorder
  2724 
  2725     pordered_ab_group_add               ~> ordered_ab_group_add
  2726     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  2727     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  2728     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  2729     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  2730     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  2731     pordered_cancel_semiring            ~> ordered_cancel_semiring
  2732     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  2733     pordered_comm_ring                  ~> ordered_comm_ring
  2734     pordered_comm_semiring              ~> ordered_comm_semiring
  2735     pordered_ring                       ~> ordered_ring
  2736     pordered_ring_abs                   ~> ordered_ring_abs
  2737     pordered_semiring                   ~> ordered_semiring
  2738 
  2739     ordered_ab_group_add                ~> linordered_ab_group_add
  2740     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  2741     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  2742     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  2743     ordered_field                       ~> linordered_field
  2744     ordered_field_no_lb                 ~> linordered_field_no_lb
  2745     ordered_field_no_ub                 ~> linordered_field_no_ub
  2746     ordered_field_dense_linear_order    ~> dense_linordered_field
  2747     ordered_idom                        ~> linordered_idom
  2748     ordered_ring                        ~> linordered_ring
  2749     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  2750     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  2751     ordered_ring_strict                 ~> linordered_ring_strict
  2752     ordered_semidom                     ~> linordered_semidom
  2753     ordered_semiring                    ~> linordered_semiring
  2754     ordered_semiring_1                  ~> linordered_semiring_1
  2755     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  2756     ordered_semiring_strict             ~> linordered_semiring_strict
  2757 
  2758   The following slightly odd type classes have been moved to a
  2759   separate theory Library/Lattice_Algebras:
  2760 
  2761     lordered_ab_group_add               ~> lattice_ab_group_add
  2762     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  2763     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  2764     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  2765     lordered_ring                       ~> lattice_ring
  2766 
  2767 INCOMPATIBILITY.
  2768 
  2769 * Refined field classes:
  2770   - classes division_ring_inverse_zero, field_inverse_zero,
  2771     linordered_field_inverse_zero include rule inverse 0 = 0 --
  2772     subsumes former division_by_zero class;
  2773   - numerous lemmas have been ported from field to division_ring.
  2774 INCOMPATIBILITY.
  2775 
  2776 * Refined algebra theorem collections:
  2777   - dropped theorem group group_simps, use algebra_simps instead;
  2778   - dropped theorem group ring_simps, use field_simps instead;
  2779   - proper theorem collection field_simps subsumes former theorem
  2780     groups field_eq_simps and field_simps;
  2781   - dropped lemma eq_minus_self_iff which is a duplicate for
  2782     equal_neg_zero.
  2783 INCOMPATIBILITY.
  2784 
  2785 * Theory Finite_Set and List: some lemmas have been generalized from
  2786 sets to lattices:
  2787 
  2788   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  2789   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  2790   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  2791   union_Union_fold_union        ~> sup_Sup_fold_sup
  2792   Inter_fold_inter              ~> Inf_fold_inf
  2793   Union_fold_union              ~> Sup_fold_sup
  2794   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  2795   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  2796   INTER_fold_inter              ~> INFI_fold_inf
  2797   UNION_fold_union              ~> SUPR_fold_sup
  2798 
  2799 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  2800 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  2801 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  2802 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  2803 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  2804 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  2805 
  2806 * Reorganized theory Multiset: swapped notation of pointwise and
  2807 multiset order:
  2808 
  2809   - pointwise ordering is instance of class order with standard syntax
  2810     <= and <;
  2811   - multiset ordering has syntax <=# and <#; partial order properties
  2812     are provided by means of interpretation with prefix
  2813     multiset_order;
  2814   - less duplication, less historical organization of sections,
  2815     conversion from associations lists to multisets, rudimentary code
  2816     generation;
  2817   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  2818     if needed.
  2819 
  2820 Renamed:
  2821 
  2822   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  2823   multi_count_ext  ~>  multiset_ext
  2824   diff_union_inverse2  ~>  diff_union_cancelR
  2825 
  2826 INCOMPATIBILITY.
  2827 
  2828 * Theory Permutation: replaced local "remove" by List.remove1.
  2829 
  2830 * Code generation: ML and OCaml code is decorated with signatures.
  2831 
  2832 * Theory List: added transpose.
  2833 
  2834 * Library/Nat_Bijection.thy is a collection of bijective functions
  2835 between nat and other types, which supersedes the older libraries
  2836 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  2837 
  2838   Constants:
  2839   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  2840   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  2841   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  2842   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  2843   Countable.pair_encode           ~> prod_encode
  2844   NatIso.prod2nat                 ~> prod_encode
  2845   NatIso.nat2prod                 ~> prod_decode
  2846   NatIso.sum2nat                  ~> sum_encode
  2847   NatIso.nat2sum                  ~> sum_decode
  2848   NatIso.list2nat                 ~> list_encode
  2849   NatIso.nat2list                 ~> list_decode
  2850   NatIso.set2nat                  ~> set_encode
  2851   NatIso.nat2set                  ~> set_decode
  2852 
  2853   Lemmas:
  2854   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2855   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2856   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2857   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2858   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2859   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2860   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2861   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2862   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2863   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2864   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2865   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2866   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2867 
  2868 * Sledgehammer:
  2869   - Renamed ATP commands:
  2870     atp_info     ~> sledgehammer running_atps
  2871     atp_kill     ~> sledgehammer kill_atps
  2872     atp_messages ~> sledgehammer messages
  2873     atp_minimize ~> sledgehammer minimize
  2874     print_atps   ~> sledgehammer available_atps
  2875     INCOMPATIBILITY.
  2876   - Added user's manual ("isabelle doc sledgehammer").
  2877   - Added option syntax and "sledgehammer_params" to customize
  2878     Sledgehammer's behavior.  See the manual for details.
  2879   - Modified the Isar proof reconstruction code so that it produces
  2880     direct proofs rather than proofs by contradiction.  (This feature
  2881     is still experimental.)
  2882   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2883     full-typed mode.
  2884   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2885 
  2886 * Nitpick:
  2887   - Added and implemented "binary_ints" and "bits" options.
  2888   - Added "std" option and implemented support for nonstandard models.
  2889   - Added and implemented "finitize" option to improve the precision
  2890     of infinite datatypes based on a monotonicity analysis.
  2891   - Added support for quotient types.
  2892   - Added support for "specification" and "ax_specification"
  2893     constructs.
  2894   - Added support for local definitions (for "function" and
  2895     "termination" proofs).
  2896   - Added support for term postprocessors.
  2897   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2898   - Improved efficiency of "destroy_constrs" optimization.
  2899   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2900     record getters.
  2901   - Fixed soundness bug related to higher-order constructors.
  2902   - Fixed soundness bug when "full_descrs" is enabled.
  2903   - Improved precision of set constructs.
  2904   - Added "atoms" option.
  2905   - Added cache to speed up repeated Kodkod invocations on the same
  2906     problems.
  2907   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2908     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2909     "SAT4J_Light".  INCOMPATIBILITY.
  2910   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2911     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2912   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2913 
  2914 * Method "induct" now takes instantiations of the form t, where t is not
  2915   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2916   If this is not intended, t has to be enclosed in parentheses.
  2917   By default, the equalities generated by definitional instantiations
  2918   are pre-simplified, which may cause parameters of inductive cases
  2919   to disappear, or may even delete some of the inductive cases.
  2920   Use "induct (no_simp)" instead of "induct" to restore the old
  2921   behaviour. The (no_simp) option is also understood by the "cases"
  2922   and "nominal_induct" methods, which now perform pre-simplification, too.
  2923   INCOMPATIBILITY.
  2924 
  2925 
  2926 *** HOLCF ***
  2927 
  2928 * Variable names in lemmas generated by the domain package have
  2929 changed; the naming scheme is now consistent with the HOL datatype
  2930 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2931 
  2932 * The domain package no longer defines the function "foo_copy" for
  2933 recursive domain "foo".  The reach lemma is now stated directly in
  2934 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2935 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2936 
  2937 * Most definedness lemmas generated by the domain package (previously
  2938 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2939 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2940 Proofs that used definedness lemmas as intro rules may break,
  2941 potential INCOMPATIBILITY.
  2942 
  2943 * Induction and casedist rules generated by the domain package now
  2944 declare proper case_names (one called "bottom", and one named for each
  2945 constructor).  INCOMPATIBILITY.
  2946 
  2947 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2948 rules are generated for each domain, INCOMPATIBILITY.
  2949 
  2950   foo_bar.reach       ~> foo.reach  bar.reach
  2951   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2952 
  2953 * Some lemmas generated by the domain package have been renamed for
  2954 consistency with the datatype package, INCOMPATIBILITY.
  2955 
  2956   foo.ind        ~> foo.induct
  2957   foo.finite_ind ~> foo.finite_induct
  2958   foo.coind      ~> foo.coinduct
  2959   foo.casedist   ~> foo.exhaust
  2960   foo.exhaust    ~> foo.nchotomy
  2961 
  2962 * For consistency with other definition packages, the fixrec package
  2963 now generates qualified theorem names, INCOMPATIBILITY.
  2964 
  2965   foo_simps  ~> foo.simps
  2966   foo_unfold ~> foo.unfold
  2967   foo_induct ~> foo.induct
  2968 
  2969 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2970 method and internal fixrec proofs now use the default simpset instead.
  2971 INCOMPATIBILITY.
  2972 
  2973 * The "contlub" predicate has been removed.  Proof scripts should use
  2974 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2975 
  2976 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2977 
  2978 * The constants cpair, cfst, and csnd have been removed in favor of
  2979 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2980 
  2981 
  2982 *** ML ***
  2983 
  2984 * Antiquotations for basic formal entities:
  2985 
  2986     @{class NAME}         -- type class
  2987     @{class_syntax NAME}  -- syntax representation of the above
  2988 
  2989     @{type_name NAME}     -- logical type
  2990     @{type_abbrev NAME}   -- type abbreviation
  2991     @{nonterminal NAME}   -- type of concrete syntactic category
  2992     @{type_syntax NAME}   -- syntax representation of any of the above
  2993 
  2994     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2995     @{const_abbrev NAME}  -- abbreviated constant
  2996     @{const_syntax NAME}  -- syntax representation of any of the above
  2997 
  2998 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  2999 syntax constant (cf. 'syntax' command).
  3000 
  3001 * Antiquotation @{make_string} inlines a function to print arbitrary
  3002 values similar to the ML toplevel.  The result is compiler dependent
  3003 and may fall back on "?" in certain situations.
  3004 
  3005 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  3006 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  3007 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  3008 not work with the asynchronous Isar document model.
  3009 
  3010 * Configuration options now admit dynamic default values, depending on
  3011 the context or even global references.
  3012 
  3013 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  3014 uses an efficient external library if available (for Poly/ML).
  3015 
  3016 * Renamed some important ML structures, while keeping the old names
  3017 for some time as aliases within the structure Legacy:
  3018 
  3019   OuterKeyword  ~>  Keyword
  3020   OuterLex      ~>  Token
  3021   OuterParse    ~>  Parse
  3022   OuterSyntax   ~>  Outer_Syntax
  3023   PrintMode     ~>  Print_Mode
  3024   SpecParse     ~>  Parse_Spec
  3025   ThyInfo       ~>  Thy_Info
  3026   ThyLoad       ~>  Thy_Load
  3027   ThyOutput     ~>  Thy_Output
  3028   TypeInfer     ~>  Type_Infer
  3029 
  3030 Note that "open Legacy" simplifies porting of sources, but forgetting
  3031 to remove it again will complicate porting again in the future.
  3032 
  3033 * Most operations that refer to a global context are named
  3034 accordingly, e.g. Simplifier.global_context or
  3035 ProofContext.init_global.  There are some situations where a global
  3036 context actually works, but under normal circumstances one needs to
  3037 pass the proper local context through the code!
  3038 
  3039 * Discontinued old TheoryDataFun with its copy/init operation -- data
  3040 needs to be pure.  Functor Theory_Data_PP retains the traditional
  3041 Pretty.pp argument to merge, which is absent in the standard
  3042 Theory_Data version.
  3043 
  3044 * Sorts.certify_sort and derived "cert" operations for types and terms
  3045 no longer minimize sorts.  Thus certification at the boundary of the
  3046 inference kernel becomes invariant under addition of class relations,
  3047 which is an important monotonicity principle.  Sorts are now minimized
  3048 in the syntax layer only, at the boundary between the end-user and the
  3049 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  3050 explicitly in rare situations.
  3051 
  3052 * Renamed old-style Drule.standard to Drule.export_without_context, to
  3053 emphasize that this is in no way a standard operation.
  3054 INCOMPATIBILITY.
  3055 
  3056 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  3057 usual for resolution.  Rare INCOMPATIBILITY.
  3058 
  3059 * Renamed varify/unvarify operations to varify_global/unvarify_global
  3060 to emphasize that these only work in a global situation (which is
  3061 quite rare).
  3062 
  3063 * Curried take and drop in library.ML; negative length is interpreted
  3064 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  3065 
  3066 * Proof terms: type substitutions on proof constants now use canonical
  3067 order of type variables.  INCOMPATIBILITY for tools working with proof
  3068 terms.
  3069 
  3070 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  3071 may no longer carry premises.  User-level specifications are
  3072 transformed accordingly by Thm.add_axiom/add_def.
  3073 
  3074 
  3075 *** System ***
  3076 
  3077 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  3078 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  3079 proof terms are enabled unconditionally in the new HOL-Proofs image.
  3080 
  3081 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  3082 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  3083 respectively.
  3084 
  3085 * Old lib/scripts/polyml-platform is superseded by the
  3086 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  3087 variant, even on a 64 bit machine.  The following example setting
  3088 prefers 64 bit if available:
  3089 
  3090   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  3091 
  3092 * The preliminary Isabelle/jEdit application demonstrates the emerging
  3093 Isabelle/Scala layer for advanced prover interaction and integration.
  3094 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  3095 component.
  3096 
  3097 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  3098 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  3099 similar to the default assignment of the document preparation system
  3100 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  3101 provides some operations for direct access to the font without asking
  3102 the user for manual installation.
  3103 
  3104 
  3105 
  3106 New in Isabelle2009-1 (December 2009)
  3107 -------------------------------------
  3108 
  3109 *** General ***
  3110 
  3111 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  3112 one backslash should be used, even in ML sources.
  3113 
  3114 
  3115 *** Pure ***
  3116 
  3117 * Locale interpretation propagates mixins along the locale hierarchy.
  3118 The currently only available mixins are the equations used to map
  3119 local definitions to terms of the target domain of an interpretation.
  3120 
  3121 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  3122 loc" to print all interpretations of locale "loc" in the theory.
  3123 Interpretations in proofs are not shown.
  3124 
  3125 * Thoroughly revised locales tutorial.  New section on conditional
  3126 interpretation.
  3127 
  3128 * On instantiation of classes, remaining undefined class parameters
  3129 are formally declared.  INCOMPATIBILITY.
  3130 
  3131 
  3132 *** Document preparation ***
  3133 
  3134 * New generalized style concept for printing terms: @{foo (style) ...}
  3135 instead of @{foo_style style ...}  (old form is still retained for
  3136 backward compatibility).  Styles can be also applied for
  3137 antiquotations prop, term_type and typeof.
  3138 
  3139 
  3140 *** HOL ***
  3141 
  3142 * New proof method "smt" for a combination of first-order logic with
  3143 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  3144 fixed-size bitvectors; there is also basic support for higher-order
  3145 features (esp. lambda abstractions).  It is an incomplete decision
  3146 procedure based on external SMT solvers using the oracle mechanism;
  3147 for the SMT solver Z3, this method is proof-producing.  Certificates
  3148 are provided to avoid calling the external solvers solely for
  3149 re-checking proofs.  Due to a remote SMT service there is no need for
  3150 installing SMT solvers locally.  See src/HOL/SMT.
  3151 
  3152 * New commands to load and prove verification conditions generated by
  3153 the Boogie program verifier or derived systems (e.g. the Verifying C
  3154 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  3155 
  3156 * New counterexample generator tool 'nitpick' based on the Kodkod
  3157 relational model finder.  See src/HOL/Tools/Nitpick and
  3158 src/HOL/Nitpick_Examples.
  3159 
  3160 * New commands 'code_pred' and 'values' to invoke the predicate
  3161 compiler and to enumerate values of inductive predicates.
  3162 
  3163 * A tabled implementation of the reflexive transitive closure.
  3164 
  3165 * New implementation of quickcheck uses generic code generator;
  3166 default generators are provided for all suitable HOL types, records
  3167 and datatypes.  Old quickcheck can be re-activated importing theory
  3168 Library/SML_Quickcheck.
  3169 
  3170 * New testing tool Mirabelle for automated proof tools.  Applies
  3171 several tools and tactics like sledgehammer, metis, or quickcheck, to
  3172 every proof step in a theory.  To be used in batch mode via the
  3173 "mirabelle" utility.
  3174 
  3175 * New proof method "sos" (sum of squares) for nonlinear real
  3176 arithmetic (originally due to John Harison). It requires theory
  3177 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  3178 works well in practice on quantifier-free real arithmetic with +, -,
  3179 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  3180 inequalities between polynomials.  It makes use of external
  3181 semidefinite programming solvers.  Method "sos" generates a
  3182 certificate that can be pasted into the proof thus avoiding the need
  3183 to call an external tool every time the proof is checked.  See
  3184 src/HOL/Library/Sum_Of_Squares.
  3185 
  3186 * New method "linarith" invokes existing linear arithmetic decision
  3187 procedure only.
  3188 
  3189 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  3190 
  3191 * New Sledgehammer option "Full Types" in Proof General settings menu.
  3192 Causes full type information to be output to the ATPs.  This slows
  3193 ATPs down considerably but eliminates a source of unsound "proofs"
  3194 that fail later.
  3195 
  3196 * New method "metisFT": A version of metis that uses full type
  3197 information in order to avoid failures of proof reconstruction.
  3198 
  3199 * New evaluator "approximate" approximates an real valued term using
  3200 the same method as the approximation method.
  3201 
  3202 * Method "approximate" now supports arithmetic expressions as
  3203 boundaries of intervals and implements interval splitting and Taylor
  3204 series expansion.
  3205 
  3206 * ML antiquotation @{code_datatype} inserts definition of a datatype
  3207 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  3208 
  3209 * New theory SupInf of the supremum and infimum operators for sets of
  3210 reals.
  3211 
  3212 * New theory Probability, which contains a development of measure
  3213 theory, eventually leading to Lebesgue integration and probability.
  3214 
  3215 * Extended Multivariate Analysis to include derivation and Brouwer's
  3216 fixpoint theorem.
  3217 
  3218 * Reorganization of number theory, INCOMPATIBILITY:
  3219   - new number theory development for nat and int, in theories Divides
  3220     and GCD as well as in new session Number_Theory
  3221   - some constants and facts now suffixed with _nat and _int
  3222     accordingly
  3223   - former session NumberTheory now named Old_Number_Theory, including
  3224     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  3225   - moved theory Pocklington from src/HOL/Library to
  3226     src/HOL/Old_Number_Theory
  3227 
  3228 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  3229 lcm of finite and infinite sets. It is shown that they form a complete
  3230 lattice.
  3231 
  3232 * Class semiring_div requires superclass no_zero_divisors and proof of
  3233 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  3234 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  3235 generalized to class semiring_div, subsuming former theorems
  3236 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  3237 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  3238 INCOMPATIBILITY.
  3239 
  3240 * Refinements to lattice classes and sets:
  3241   - less default intro/elim rules in locale variant, more default
  3242     intro/elim rules in class variant: more uniformity
  3243   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  3244     le_inf_iff
  3245   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  3246     sup_aci)
  3247   - renamed ACI to inf_sup_aci
  3248   - new class "boolean_algebra"
  3249   - class "complete_lattice" moved to separate theory
  3250     "Complete_Lattice"; corresponding constants (and abbreviations)
  3251     renamed and with authentic syntax:
  3252     Set.Inf ~>    Complete_Lattice.Inf
  3253     Set.Sup ~>    Complete_Lattice.Sup
  3254     Set.INFI ~>   Complete_Lattice.INFI
  3255     Set.SUPR ~>   Complete_Lattice.SUPR
  3256     Set.Inter ~>  Complete_Lattice.Inter
  3257     Set.Union ~>  Complete_Lattice.Union
  3258     Set.INTER ~>  Complete_Lattice.INTER
  3259     Set.UNION ~>  Complete_Lattice.UNION
  3260   - authentic syntax for
  3261     Set.Pow
  3262     Set.image
  3263   - mere abbreviations:
  3264     Set.empty               (for bot)
  3265     Set.UNIV                (for top)
  3266     Set.inter               (for inf, formerly Set.Int)
  3267     Set.union               (for sup, formerly Set.Un)
  3268     Complete_Lattice.Inter  (for Inf)
  3269     Complete_Lattice.Union  (for Sup)
  3270     Complete_Lattice.INTER  (for INFI)
  3271     Complete_Lattice.UNION  (for SUPR)
  3272   - object-logic definitions as far as appropriate
  3273 
  3274 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  3275 Un_subset_iff are explicitly deleted as default simp rules; then also
  3276 their lattice counterparts le_inf_iff and le_sup_iff have to be
  3277 deleted to achieve the desired effect.
  3278 
  3279 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  3280 rules by default any longer; the same applies to min_max.inf_absorb1
  3281 etc.  INCOMPATIBILITY.
  3282 
  3283 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  3284 pred_set_conv by default.  INCOMPATIBILITY.
  3285 
  3286 * Power operations on relations and functions are now one dedicated
  3287 constant "compow" with infix syntax "^^".  Power operation on
  3288 multiplicative monoids retains syntax "^" and is now defined generic
  3289 in class power.  INCOMPATIBILITY.
  3290 
  3291 * Relation composition "R O S" now has a more standard argument order:
  3292 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  3293 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  3294 break, since the O_assoc rule was not rewritten like this.  Fix using
  3295 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  3296 
  3297 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  3298 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  3299 INCOMPATIBILITY.
  3300 
  3301 * Most rules produced by inductive and datatype package have mandatory
  3302 prefixes.  INCOMPATIBILITY.
  3303 
  3304 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  3305 the attribute of the same name.  Each of the theorems in the list
  3306 DERIV_intros assumes composition with an additional function and
  3307 matches a variable to the derivative, which has to be solved by the
  3308 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  3309 of most elementary terms.  Former Maclauren.DERIV_tac and
  3310 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  3311 INCOMPATIBILITY.
  3312 
  3313 * Code generator attributes follow the usual underscore convention:
  3314     code_unfold     replaces    code unfold
  3315     code_post       replaces    code post
  3316     etc.
  3317   INCOMPATIBILITY.
  3318 
  3319 * Renamed methods:
  3320     sizechange -> size_change
  3321     induct_scheme -> induction_schema
  3322   INCOMPATIBILITY.
  3323 
  3324 * Discontinued abbreviation "arbitrary" of constant "undefined".
  3325 INCOMPATIBILITY, use "undefined" directly.
  3326 
  3327 * Renamed theorems:
  3328     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  3329     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  3330     Suc_plus1 -> Suc_eq_plus1
  3331     *anti_sym -> *antisym*
  3332     vector_less_eq_def -> vector_le_def
  3333   INCOMPATIBILITY.
  3334 
  3335 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  3336 INCOMPATIBILITY.
  3337 
  3338 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  3339 INCOMPATIBILITY.
  3340 
  3341 
  3342 *** HOLCF ***
  3343 
  3344 * Theory Representable defines a class "rep" of domains that are
  3345 representable (via an ep-pair) in the universal domain type "udom".
  3346 Instances are provided for all type constructors defined in HOLCF.
  3347 
  3348 * The 'new_domain' command is a purely definitional version of the
  3349 domain package, for representable domains.  Syntax is identical to the
  3350 old domain package.  The 'new_domain' package also supports indirect
  3351 recursion using previously-defined type constructors.  See
  3352 src/HOLCF/ex/New_Domain.thy for examples.
  3353 
  3354 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  3355 on the left-hand side of an equation, and then performs
  3356 simplification.  Rewriting is done using rules declared with the
  3357 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  3358 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  3359 
  3360 * The pattern-match compiler in 'fixrec' can now handle constructors
  3361 with HOL function types.  Pattern-match combinators for the Pair
  3362 constructor are pre-configured.
  3363 
  3364 * The 'fixrec' package now produces better fixed-point induction rules
  3365 for mutually-recursive definitions:  Induction rules have conclusions
  3366 of the form "P foo bar" instead of "P <foo, bar>".
  3367 
  3368 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  3369 been renamed to "below".  The name "below" now replaces "less" in many
  3370 theorem names.  (Legacy theorem names using "less" are still supported
  3371 as well.)
  3372 
  3373 * The 'fixrec' package now supports "bottom patterns".  Bottom
  3374 patterns can be used to generate strictness rules, or to make
  3375 functions more strict (much like the bang-patterns supported by the
  3376 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  3377 examples.
  3378 
  3379 
  3380 *** ML ***
  3381 
  3382 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  3383 errors and run-time exceptions, including detailed source positions.
  3384 
  3385 * Structure Name_Space (formerly NameSpace) now manages uniquely
  3386 identified entries, with some additional information such as source
  3387 position, logical grouping etc.
  3388 
  3389 * Theory and context data is now introduced by the simplified and
  3390 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  3391 to be pure, but the old TheoryDataFun for mutable data (with explicit
  3392 copy operation) is still available for some time.
  3393 
  3394 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  3395 provides a high-level programming interface to synchronized state
  3396 variables with atomic update.  This works via pure function
  3397 application within a critical section -- its runtime should be as
  3398 short as possible; beware of deadlocks if critical code is nested,
  3399 either directly or indirectly via other synchronized variables!
  3400 
  3401 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  3402 wraps raw ML references, explicitly indicating their non-thread-safe
  3403 behaviour.  The Isar toplevel keeps this structure open, to
  3404 accommodate Proof General as well as quick and dirty interactive
  3405 experiments with references.
  3406 
  3407 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  3408 parallel tactical reasoning.
  3409 
  3410 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  3411 are similar to SUBPROOF, but are slightly more flexible: only the
  3412 specified parts of the subgoal are imported into the context, and the
  3413 body tactic may introduce new subgoals and schematic variables.
  3414 
  3415 * Old tactical METAHYPS, which does not observe the proof context, has
  3416 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  3417 or Subgoal.FOCUS etc.
  3418 
  3419 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  3420 functors have their own ML name space there is no point to mark them
  3421 separately.)  Minor INCOMPATIBILITY.
  3422 
  3423 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  3424 
  3425 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  3426 INCOMPATIBILITY.
  3427 
  3428 * Operations of structure Skip_Proof no longer require quick_and_dirty
  3429 mode, which avoids critical setmp.
  3430 
  3431 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  3432 combinators for "args".  INCOMPATIBILITY, need to use simplified
  3433 Attrib/Method.setup introduced in Isabelle2009.
  3434 
  3435 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  3436 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  3437 last resort.  INCOMPATIBILITY.
  3438 
  3439 * Display.pretty_thm now requires a proper context (cf. former
  3440 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  3441 or even Display.pretty_thm_without_context as last resort.
  3442 INCOMPATIBILITY.
  3443 
  3444 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  3445 Syntax.pretty_typ/term directly, preferably with proper context
  3446 instead of global theory.
  3447 
  3448 
  3449 *** System ***
  3450 
  3451 * Further fine tuning of parallel proof checking, scales up to 8 cores
  3452 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  3453 usedir option -q.
  3454 
  3455 * Support for additional "Isabelle components" via etc/components, see
  3456 also the system manual.
  3457 
  3458 * The isabelle makeall tool now operates on all components with
  3459 IsaMakefile, not just hardwired "logics".
  3460 
  3461 * Removed "compress" option from isabelle-process and isabelle usedir;
  3462 this is always enabled.
  3463 
  3464 * Discontinued support for Poly/ML 4.x versions.
  3465 
  3466 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  3467 on a given logic image.  This requires the lighttpd webserver and is
  3468 currently supported on Linux only.
  3469 
  3470 
  3471 
  3472 New in Isabelle2009 (April 2009)
  3473 --------------------------------
  3474 
  3475 *** General ***
  3476 
  3477 * Simplified main Isabelle executables, with less surprises on
  3478 case-insensitive file-systems (such as Mac OS).
  3479 
  3480   - The main Isabelle tool wrapper is now called "isabelle" instead of
  3481     "isatool."
  3482 
  3483   - The former "isabelle" alias for "isabelle-process" has been
  3484     removed (should rarely occur to regular users).
  3485 
  3486   - The former "isabelle-interface" and its alias "Isabelle" have been
  3487     removed (interfaces are now regular Isabelle tools).
  3488 
  3489 Within scripts and make files, the Isabelle environment variables
  3490 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  3491 respectively.  (The latter are still available as legacy feature.)
  3492 
  3493 The old isabelle-interface wrapper could react in confusing ways if
  3494 the interface was uninstalled or changed otherwise.  Individual
  3495 interface tool configuration is now more explicit, see also the
  3496 Isabelle system manual.  In particular, Proof General is now available
  3497 via "isabelle emacs".
  3498 
  3499 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  3500 purge installed copies of Isabelle executables and re-run "isabelle
  3501 install -p ...", or use symlinks.
  3502 
  3503 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  3504 old ~/isabelle, which was slightly non-standard and apt to cause
  3505 surprises on case-insensitive file-systems (such as Mac OS).
  3506 
  3507 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  3508 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  3509 care is required when using older releases of Isabelle.  Note that
  3510 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  3511 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  3512 
  3513 * Proofs of fully specified statements are run in parallel on
  3514 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  3515 a regular 4-core machine, if the initial heap space is made reasonably
  3516 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  3517 
  3518 * The main reference manuals ("isar-ref", "implementation", and
  3519 "system") have been updated and extended.  Formally checked references
  3520 as hyperlinks are now available uniformly.
  3521 
  3522 
  3523 *** Pure ***
  3524 
  3525 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  3526 respects.  The most important changes are listed below.  See the
  3527 Tutorial on Locales ("locales" manual) for details.
  3528 
  3529 - In locale expressions, instantiation replaces renaming.  Parameters
  3530 must be declared in a for clause.  To aid compatibility with previous
  3531 parameter inheritance, in locale declarations, parameters that are not
  3532 'touched' (instantiation position "_" or omitted) are implicitly added
  3533 with their syntax at the beginning of the for clause.
  3534 
  3535 - Syntax from abbreviations and definitions in locales is available in
  3536 locale expressions and context elements.  The latter is particularly
  3537 useful in locale declarations.
  3538 
  3539 - More flexible mechanisms to qualify names generated by locale
  3540 expressions.  Qualifiers (prefixes) may be specified in locale
  3541 expressions, and can be marked as mandatory (syntax: "name!:") or
  3542 optional (syntax "name?:").  The default depends for plain "name:"
  3543 depends on the situation where a locale expression is used: in
  3544 commands 'locale' and 'sublocale' prefixes are optional, in
  3545 'interpretation' and 'interpret' prefixes are mandatory.  The old
  3546 implicit qualifiers derived from the parameter names of a locale are
  3547 no longer generated.
  3548 
  3549 - Command "sublocale l < e" replaces "interpretation l < e".  The
  3550 instantiation clause in "interpretation" and "interpret" (square
  3551 brackets) is no longer available.  Use locale expressions.
  3552 
  3553 - When converting proof scripts, mandatory qualifiers in
  3554 'interpretation' and 'interpret' should be retained by default, even
  3555 if this is an INCOMPATIBILITY compared to former behavior.  In the
  3556 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  3557 in locale expressions range over a single locale instance only.
  3558 
  3559 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  3560 In existing theorem specifications replace the includes element by the
  3561 respective context elements of the included locale, omitting those
  3562 that are already present in the theorem specification.  Multiple
  3563 assume elements of a locale should be replaced by a single one
  3564 involving the locale predicate.  In the proof body, declarations (most
  3565 notably theorems) may be regained by interpreting the respective
  3566 locales in the proof context as required (command "interpret").
  3567 
  3568 If using "includes" in replacement of a target solely because the
  3569 parameter types in the theorem are not as general as in the target,
  3570 consider declaring a new locale with additional type constraints on
  3571 the parameters (context element "constrains").
  3572 
  3573 - Discontinued "locale (open)".  INCOMPATIBILITY.
  3574 
  3575 - Locale interpretation commands no longer attempt to simplify goal.
  3576 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  3577 methods intro_locales and unfold_locales to clarify.
  3578 
  3579 - Locale interpretation commands no longer accept interpretation
  3580 attributes.  INCOMPATIBILITY.
  3581 
  3582 * Class declaration: so-called "base sort" must not be given in import
  3583 list any longer, but is inferred from the specification.  Particularly
  3584 in HOL, write
  3585 
  3586     class foo = ...
  3587 
  3588 instead of
  3589 
  3590     class foo = type + ...
  3591 
  3592 * Class target: global versions of theorems stemming do not carry a
  3593 parameter prefix any longer.  INCOMPATIBILITY.
  3594 
  3595 * Class 'instance' command no longer accepts attached definitions.
  3596 INCOMPATIBILITY, use proper 'instantiation' target instead.
  3597 
  3598 * Recovered hiding of consts, which was accidentally broken in
  3599 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  3600 makes c inaccessible; consider using ``hide (open) const c'' instead.
  3601 
  3602 * Slightly more coherent Pure syntax, with updated documentation in
  3603 isar-ref manual.  Removed locales meta_term_syntax and
  3604 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  3605 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  3606 directly in regular applications.
  3607 
  3608 * There is a new syntactic category "float_const" for signed decimal
  3609 fractions (e.g. 123.45 or -123.45).
  3610 
  3611 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  3612 interface with 'setup' command instead.
  3613 
  3614 * Command 'local_setup' is similar to 'setup', but operates on a local
  3615 theory context.
  3616 
  3617 * The 'axiomatization' command now only works within a global theory
  3618 context.  INCOMPATIBILITY.
  3619 
  3620 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  3621 hypotheses.  Sorts required in the course of reasoning need to be
  3622 covered by the constraints in the initial statement, completed by the
  3623 type instance information of the background theory.  Non-trivial sort
  3624 hypotheses, which rarely occur in practice, may be specified via
  3625 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  3626 
  3627   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  3628 
  3629 The result contains an implicit sort hypotheses as before --
  3630 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  3631 normalization.
  3632 
  3633 * Generalized Isar history, with support for linear undo, direct state
  3634 addressing etc.
  3635 
  3636 * Changed defaults for unify configuration options:
  3637 
  3638   unify_trace_bound = 50 (formerly 25)
  3639   unify_search_bound = 60 (formerly 30)
  3640 
  3641 * Different bookkeeping for code equations (INCOMPATIBILITY):
  3642 
  3643   a) On theory merge, the last set of code equations for a particular
  3644      constant is taken (in accordance with the policy applied by other
  3645      parts of the code generator framework).
  3646 
  3647   b) Code equations stemming from explicit declarations (e.g. code
  3648      attribute) gain priority over default code equations stemming
  3649      from definition, primrec, fun etc.
  3650 
  3651 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  3652 
  3653 * Unified theorem tables for both code generators.  Thus [code
  3654 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  3655 
  3656 * Command 'find_consts' searches for constants based on type and name
  3657 patterns, e.g.
  3658 
  3659     find_consts "_ => bool"
  3660 
  3661 By default, matching is against subtypes, but it may be restricted to
  3662 the whole type.  Searching by name is possible.  Multiple queries are
  3663 conjunctive and queries may be negated by prefixing them with a
  3664 hyphen:
  3665 
  3666     find_consts strict: "_ => bool" name: "Int" -"int => int"
  3667 
  3668 * New 'find_theorems' criterion "solves" matches theorems that
  3669 directly solve the current goal (modulo higher-order unification).
  3670 
  3671 * Auto solve feature for main theorem statements: whenever a new goal
  3672 is stated, "find_theorems solves" is called; any theorems that could
  3673 solve the lemma directly are listed as part of the goal state.
  3674 Cf. associated options in Proof General Isabelle settings menu,
  3675 enabled by default, with reasonable timeout for pathological cases of
  3676 higher-order unification.
  3677 
  3678 
  3679 *** Document preparation ***
  3680 
  3681 * Antiquotation @{lemma} now imitates a regular terminal proof,
  3682 demanding keyword 'by' and supporting the full method expression
  3683 syntax just like the Isar command 'by'.
  3684 
  3685 
  3686 *** HOL ***
  3687 
  3688 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  3689 points Main and Complex_Main remain as before.
  3690 
  3691 * Logic image HOL-Plain provides a minimal HOL with the most important
  3692 tools available (inductive, datatype, primrec, ...).  This facilitates
  3693 experimentation and tool development.  Note that user applications
  3694 (and library theories) should never refer to anything below theory
  3695 Main, as before.
  3696 
  3697 * Logic image HOL-Main stops at theory Main, and thus facilitates
  3698 experimentation due to shorter build times.
  3699 
  3700 * Logic image HOL-NSA contains theories of nonstandard analysis which
  3701 were previously part of former HOL-Complex.  Entry point Hyperreal
  3702 remains valid, but theories formerly using Complex_Main should now use
  3703 new entry point Hypercomplex.
  3704 
  3705 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  3706 Posix processes.  Avoids potentially expensive forking of the ML
  3707 process.  New thread-based implementation also works on non-Unix
  3708 platforms (Cygwin).  Provers are no longer hardwired, but defined
  3709 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  3710 commands are covered in the isar-ref manual.
  3711 
  3712 * Wrapper scripts for remote SystemOnTPTP service allows to use
  3713 sledgehammer without local ATP installation (Vampire etc.). Other
  3714 provers may be included via suitable ML wrappers, see also
  3715 src/HOL/ATP_Linkup.thy.
  3716 
  3717 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  3718 menu.
  3719 
  3720 * The metis method no longer fails because the theorem is too trivial
  3721 (contains the empty clause).
  3722 
  3723 * The metis method now fails in the usual manner, rather than raising
  3724 an exception, if it determines that it cannot prove the theorem.
  3725 
  3726 * Method "coherent" implements a prover for coherent logic (see also
  3727 src/Tools/coherent.ML).
  3728 
  3729 * Constants "undefined" and "default" replace "arbitrary".  Usually
  3730 "undefined" is the right choice to replace "arbitrary", though
  3731 logically there is no difference.  INCOMPATIBILITY.
  3732 
  3733 * Command "value" now integrates different evaluation mechanisms.  The
  3734 result of the first successful evaluation mechanism is printed.  In
  3735 square brackets a particular named evaluation mechanisms may be
  3736 specified (currently, [SML], [code] or [nbe]).  See further
  3737 src/HOL/ex/Eval_Examples.thy.
  3738 
  3739 * Normalization by evaluation now allows non-leftlinear equations.
  3740 Declare with attribute [code nbe].
  3741 
  3742 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  3743 as the structured Isar versions "cases" and "induct", cf. the
  3744 corresponding "cases" and "induct" attributes.  Mutual induction rules
  3745 are now presented as a list of individual projections
  3746 (e.g. foo_bar.inducts for types foo and bar); the old format with
  3747 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  3748 rare situations a different rule is selected --- notably nested tuple
  3749 elimination instead of former prod.exhaust: use explicit (case_tac t
  3750 rule: prod.exhaust) here.
  3751 
  3752 * Attributes "cases", "induct", "coinduct" support "del" option.
  3753 
  3754 * Removed fact "case_split_thm", which duplicates "case_split".
  3755 
  3756 * The option datatype has been moved to a new theory Option.  Renamed
  3757 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  3758 
  3759 * New predicate "strict_mono" classifies strict functions on partial
  3760 orders.  With strict functions on linear orders, reasoning about
  3761 (in)equalities is facilitated by theorems "strict_mono_eq",
  3762 "strict_mono_less_eq" and "strict_mono_less".
  3763 
  3764 * Some set operations are now proper qualified constants with
  3765 authentic syntax.  INCOMPATIBILITY:
  3766 
  3767     op Int ~>   Set.Int
  3768     op Un ~>    Set.Un
  3769     INTER ~>    Set.INTER
  3770     UNION ~>    Set.UNION
  3771     Inter ~>    Set.Inter
  3772     Union ~>    Set.Union
  3773     {} ~>       Set.empty
  3774     UNIV ~>     Set.UNIV
  3775 
  3776 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  3777 theory Set.
  3778 
  3779 * Auxiliary class "itself" has disappeared -- classes without any
  3780 parameter are treated as expected by the 'class' command.
  3781 
  3782 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  3783 
  3784 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  3785 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  3786 
  3787 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  3788 method "approximation".  It proves formulas on real values by using
  3789 interval arithmetic.  In the formulas are also the transcendental
  3790 functions sin, cos, tan, atan, ln, exp and the constant pi are
  3791 allowed. For examples see
  3792 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  3793 
  3794 * Theory "Reflection" now resides in HOL/Library.
  3795 
  3796 * Entry point to Word library now simply named "Word".
  3797 INCOMPATIBILITY.
  3798 
  3799 * Made source layout more coherent with logical distribution
  3800 structure:
  3801 
  3802     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  3803     src/HOL/Library/Code_Message.thy ~> src/HOL/
  3804     src/HOL/Library/GCD.thy ~> src/HOL/
  3805     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  3806     src/HOL/Library/Parity.thy ~> src/HOL/
  3807     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  3808     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  3809     src/HOL/Real/Lubs.thy ~> src/HOL/
  3810     src/HOL/Real/PReal.thy ~> src/HOL/
  3811     src/HOL/Real/Rational.thy ~> src/HOL/
  3812     src/HOL/Real/RComplete.thy ~> src/HOL/
  3813     src/HOL/Real/RealDef.thy ~> src/HOL/
  3814     src/HOL/Real/RealPow.thy ~> src/HOL/
  3815     src/HOL/Real/Real.thy ~> src/HOL/
  3816     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  3817     src/HOL/Complex/Complex.thy ~> src/HOL/
  3818     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  3819     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  3820     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  3821     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  3822     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  3823     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  3824     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  3825     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  3826     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  3827     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  3828     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  3829     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  3830     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  3831     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  3832     src/HOL/Real/Float ~> src/HOL/Library/
  3833     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  3834     src/HOL/Real/RealVector.thy ~> src/HOL/
  3835 
  3836     src/HOL/arith_data.ML ~> src/HOL/Tools
  3837     src/HOL/hologic.ML ~> src/HOL/Tools
  3838     src/HOL/simpdata.ML ~> src/HOL/Tools
  3839     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  3840     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  3841     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  3842     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  3843     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  3844     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  3845     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  3846 
  3847     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  3848     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3849     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3850     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3851     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3852     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3853 
  3854 * If methods "eval" and "evaluation" encounter a structured proof
  3855 state with !!/==>, only the conclusion is evaluated to True (if
  3856 possible), avoiding strange error messages.
  3857 
  3858 * Method "sizechange" automates termination proofs using (a
  3859 modification of) the size-change principle.  Requires SAT solver.  See
  3860 src/HOL/ex/Termination.thy for examples.
  3861 
  3862 * Simplifier: simproc for let expressions now unfolds if bound
  3863 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3864 
  3865 * Method "arith": Linear arithmetic now ignores all inequalities when
  3866 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3867 
  3868 * New attribute "arith" for facts that should always be used
  3869 automatically by arithmetic. It is intended to be used locally in
  3870 proofs, e.g.
  3871 
  3872   assumes [arith]: "x > 0"
  3873 
  3874 Global usage is discouraged because of possible performance impact.
  3875 
  3876 * New classes "top" and "bot" with corresponding operations "top" and
  3877 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3878 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3879 
  3880 * Changed definition lemma "less_fun_def" in order to provide an
  3881 instance for preorders on functions; use lemma "less_le" instead.
  3882 INCOMPATIBILITY.
  3883 
  3884 * Theory Orderings: class "wellorder" moved here, with explicit
  3885 induction rule "less_induct" as assumption.  For instantiation of
  3886 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3887 INCOMPATIBILITY.
  3888 
  3889 * Theory Orderings: added class "preorder" as superclass of "order".
  3890 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3891 etc. slightly changed.  Some theorems named order_class.* now named
  3892 preorder_class.*.
  3893 
  3894 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3895 "diag" to "Id_on".
  3896 
  3897 * Theory Finite_Set: added a new fold combinator of type
  3898 
  3899   ('a => 'b => 'b) => 'b => 'a set => 'b
  3900 
  3901 Occasionally this is more convenient than the old fold combinator
  3902 which is now defined in terms of the new one and renamed to
  3903 fold_image.
  3904 
  3905 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3906 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3907 extended with further lemmas!).  At the moment both still exist but
  3908 the former will disappear at some point.
  3909 
  3910 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3911 class recpower.  Type-specific simp rules for various recpower types
  3912 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3913 
  3914 rat_power_0    -> power_0
  3915 rat_power_Suc  -> power_Suc
  3916 realpow_0      -> power_0
  3917 realpow_Suc    -> power_Suc
  3918 complexpow_0   -> power_0
  3919 complexpow_Suc -> power_Suc
  3920 power_poly_0   -> power_0
  3921 power_poly_Suc -> power_Suc
  3922 
  3923 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3924 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3925 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3926 of lemmas from Divides has been generalized from nat to class
  3927 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3928 renames resulting from duplicate elimination:
  3929 
  3930     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3931     zero_dvd_iff ~>         dvd_0_left_iff
  3932     dvd_0 ~>                dvd_0_right
  3933     DIVISION_BY_ZERO_DIV ~> div_by_0
  3934     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3935     mult_div ~>             div_mult_self2_is_id
  3936     mult_mod ~>             mod_mult_self2_is_0
  3937 
  3938 * Theory IntDiv: removed many lemmas that are instances of class-based
  3939 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3940 rename old lemmas as follows:
  3941 
  3942 dvd_diff               -> nat_dvd_diff
  3943 dvd_zminus_iff         -> dvd_minus_iff
  3944 mod_add1_eq            -> mod_add_eq
  3945 mod_mult1_eq           -> mod_mult_right_eq
  3946 mod_mult1_eq'          -> mod_mult_left_eq
  3947 mod_mult_distrib_mod   -> mod_mult_eq
  3948 nat_mod_add_left_eq    -> mod_add_left_eq
  3949 nat_mod_add_right_eq   -> mod_add_right_eq
  3950 nat_mod_div_trivial    -> mod_div_trivial
  3951 nat_mod_mod_trivial    -> mod_mod_trivial
  3952 zdiv_zadd_self1        -> div_add_self1
  3953 zdiv_zadd_self2        -> div_add_self2
  3954 zdiv_zmult_self1       -> div_mult_self2_is_id
  3955 zdiv_zmult_self2       -> div_mult_self1_is_id
  3956 zdvd_triv_left         -> dvd_triv_left
  3957 zdvd_triv_right        -> dvd_triv_right
  3958 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3959 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3960 zmod_zadd_left_eq      -> mod_add_left_eq
  3961 zmod_zadd_right_eq     -> mod_add_right_eq
  3962 zmod_zadd_self1        -> mod_add_self1
  3963 zmod_zadd_self2        -> mod_add_self2
  3964 zmod_zadd1_eq          -> mod_add_eq
  3965 zmod_zdiff1_eq         -> mod_diff_eq
  3966 zmod_zdvd_zmod         -> mod_mod_cancel
  3967 zmod_zmod_cancel       -> mod_mod_cancel
  3968 zmod_zmult_self1       -> mod_mult_self2_is_0
  3969 zmod_zmult_self2       -> mod_mult_self1_is_0
  3970 zmod_1                 -> mod_by_1
  3971 zdiv_1                 -> div_by_1
  3972 zdvd_abs1              -> abs_dvd_iff
  3973 zdvd_abs2              -> dvd_abs_iff
  3974 zdvd_refl              -> dvd_refl
  3975 zdvd_trans             -> dvd_trans
  3976 zdvd_zadd              -> dvd_add
  3977 zdvd_zdiff             -> dvd_diff
  3978 zdvd_zminus_iff        -> dvd_minus_iff
  3979 zdvd_zminus2_iff       -> minus_dvd_iff
  3980 zdvd_zmultD            -> dvd_mult_right
  3981 zdvd_zmultD2           -> dvd_mult_left
  3982 zdvd_zmult_mono        -> mult_dvd_mono
  3983 zdvd_0_right           -> dvd_0_right
  3984 zdvd_0_left            -> dvd_0_left_iff
  3985 zdvd_1_left            -> one_dvd
  3986 zminus_dvd_iff         -> minus_dvd_iff
  3987 
  3988 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3989 
  3990 * The real numbers offer decimal input syntax: 12.34 is translated
  3991 into 1234/10^2. This translation is not reversed upon output.
  3992 
  3993 * Theory Library/Polynomial defines an abstract type 'a poly of
  3994 univariate polynomials with coefficients of type 'a.  In addition to
  3995 the standard ring operations, it also supports div and mod.  Code
  3996 generation is also supported, using list-style constructors.
  3997 
  3998 * Theory Library/Inner_Product defines a class of real_inner for real
  3999 inner product spaces, with an overloaded operation inner :: 'a => 'a
  4000 => real.  Class real_inner is a subclass of real_normed_vector from
  4001 theory RealVector.
  4002 
  4003 * Theory Library/Product_Vector provides instances for the product
  4004 type 'a * 'b of several classes from RealVector and Inner_Product.
  4005 Definitions of addition, subtraction, scalar multiplication, norms,
  4006 and inner products are included.
  4007 
  4008 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  4009 addition to the field operations, numerals and case syntax are also
  4010 supported.
  4011 
  4012 * Theory Library/Diagonalize provides constructive version of Cantor's
  4013 first diagonalization argument.
  4014 
  4015 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  4016 zlcm (for int); carried together from various gcd/lcm developements in
  4017 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  4018 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  4019 may recover tupled syntax as follows:
  4020 
  4021     hide (open) const gcd
  4022     abbreviation gcd where
  4023       "gcd == (%(a, b). GCD.gcd a b)"
  4024     notation (output)
  4025       GCD.gcd ("gcd '(_, _')")
  4026 
  4027 The same works for lcm, zgcd, zlcm.
  4028 
  4029 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  4030 instantiations for algebraic structures.  Removed some duplicate
  4031 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  4032 
  4033 * ML antiquotation @{code} takes a constant as argument and generates
  4034 corresponding code in background and inserts name of the corresponding
  4035 resulting ML value/function/datatype constructor binding in place.
  4036 All occurrences of @{code} with a single ML block are generated
  4037 simultaneously.  Provides a generic and safe interface for
  4038 instrumentalizing code generation.  See
  4039 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  4040 In future you ought to refrain from ad-hoc compiling generated SML
  4041 code on the ML toplevel.  Note that (for technical reasons) @{code}
  4042 cannot refer to constants for which user-defined serializations are
  4043 set.  Refer to the corresponding ML counterpart directly in that
  4044 cases.
  4045 
  4046 * Command 'rep_datatype': instead of theorem names the command now
  4047 takes a list of terms denoting the constructors of the type to be
  4048 represented as datatype.  The characteristic theorems have to be
  4049 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  4050 have disappeared in favour of existing ones:
  4051 
  4052     unit_induct                 ~> unit.induct
  4053     prod_induct                 ~> prod.induct
  4054     sum_induct                  ~> sum.induct
  4055     Suc_Suc_eq                  ~> nat.inject
  4056     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  4057 
  4058 
  4059 *** HOL-Algebra ***
  4060 
  4061 * New locales for orders and lattices where the equivalence relation
  4062 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  4063 locales use a record structure with field eq for the equivalence.
  4064 
  4065 * New theory of factorial domains.
  4066 
  4067 * Units_l_inv and Units_r_inv are now simp rules by default.
  4068 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  4069 and/or r_inv will now also require deletion of these lemmas.
  4070 
  4071 * Renamed the following theorems, INCOMPATIBILITY:
  4072 
  4073 UpperD ~> Upper_memD
  4074 LowerD ~> Lower_memD
  4075 least_carrier ~> least_closed
  4076 greatest_carrier ~> greatest_closed
  4077 greatest_Lower_above ~> greatest_Lower_below
  4078 one_zero ~> carrier_one_zero
  4079 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  4080 
  4081 
  4082 *** HOL-Nominal ***
  4083 
  4084 * Nominal datatypes can now contain type-variables.
  4085 
  4086 * Commands 'nominal_inductive' and 'equivariance' work with local
  4087 theory targets.
  4088 
  4089 * Nominal primrec can now works with local theory targets and its
  4090 specification syntax now conforms to the general format as seen in
  4091 'inductive' etc.
  4092 
  4093 * Method "perm_simp" honours the standard simplifier attributes
  4094 (no_asm), (no_asm_use) etc.
  4095 
  4096 * The new predicate #* is defined like freshness, except that on the
  4097 left hand side can be a set or list of atoms.
  4098 
  4099 * Experimental command 'nominal_inductive2' derives strong induction
  4100 principles for inductive definitions.  In contrast to
  4101 'nominal_inductive', which can only deal with a fixed number of
  4102 binders, it can deal with arbitrary expressions standing for sets of
  4103 atoms to be avoided.  The only inductive definition we have at the
  4104 moment that needs this generalisation is the typing rule for Lets in
  4105 the algorithm W:
  4106 
  4107  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  4108  -----------------------------------------------------------------
  4109          Gamma |- Let x be t1 in t2 : T2
  4110 
  4111 In this rule one wants to avoid all the binders that are introduced by
  4112 "close Gamma T1".  We are looking for other examples where this
  4113 feature might be useful.  Please let us know.
  4114 
  4115 
  4116 *** HOLCF ***
  4117 
  4118 * Reimplemented the simplification procedure for proving continuity
  4119 subgoals.  The new simproc is extensible; users can declare additional
  4120 continuity introduction rules with the attribute [cont2cont].
  4121 
  4122 * The continuity simproc now uses a different introduction rule for
  4123 solving continuity subgoals on terms with lambda abstractions.  In
  4124 some rare cases the new simproc may fail to solve subgoals that the
  4125 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  4126 Potential INCOMPATIBILITY.
  4127 
  4128 * Command 'fixrec': specification syntax now conforms to the general
  4129 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  4130 examples.  INCOMPATIBILITY.
  4131 
  4132 
  4133 *** ZF ***
  4134 
  4135 * Proof of Zorn's Lemma for partial orders.
  4136 
  4137 
  4138 *** ML ***
  4139 
  4140 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  4141 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  4142 depends on multithreading, so timouts will not work before Poly/ML
  4143 5.2.1!
  4144 
  4145 * High-level support for concurrent ML programming, see
  4146 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  4147 particularly convenient to organize independent functional
  4148 computations.  The concept of "synchronized variables" provides a
  4149 higher-order interface for components with shared state, avoiding the
  4150 delicate details of mutexes and condition variables.  (Requires
  4151 Poly/ML 5.2.1 or later.)
  4152 
  4153 * ML bindings produced via Isar commands are stored within the Isar
  4154 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  4155 become thread-safe and work with undo as expected (concerning
  4156 top-level bindings, not side-effects on global references).
  4157 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  4158 compiler at runtime; really global bindings need to be given outside a
  4159 theory.  (Requires Poly/ML 5.2 or later.)
  4160 
  4161 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  4162 context.  Top-level ML bindings are stored within the proof context in
  4163 a purely sequential fashion, disregarding the nested proof structure.
  4164 ML bindings introduced by 'ML_prf' are discarded at the end of the
  4165 proof.  (Requires Poly/ML 5.2 or later.)
  4166 
  4167 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  4168 and Method.setup, as well as Isar commands 'attribute_setup' and
  4169 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  4170 existing code accordingly, or use plain 'setup' together with old
  4171 Method.add_method.
  4172 
  4173 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  4174 to 'a -> thm, while results are always tagged with an authentic oracle
  4175 name.  The Isar command 'oracle' is now polymorphic, no argument type
  4176 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  4177 accordingly.  Note that extra performance may be gained by producing
  4178 the cterm carefully, avoiding slow Thm.cterm_of.
  4179 
  4180 * Simplified interface for defining document antiquotations via
  4181 ThyOutput.antiquotation, ThyOutput.output, and optionally
  4182 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  4183 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  4184 examples.
  4185 
  4186 * More systematic treatment of long names, abstract name bindings, and
  4187 name space operations.  Basic operations on qualified names have been
  4188 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  4189 Long_Name.append.  Old type bstring has been mostly replaced by
  4190 abstract type binding (see structure Binding), which supports precise
  4191 qualification by packages and local theory targets, as well as proper
  4192 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  4193 bstring values into Binding.name, or better pass through abstract
  4194 bindings everywhere.  See further src/Pure/General/long_name.ML,
  4195 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  4196 
  4197 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  4198 LocalTheory.note etc.) now refer to the *full* internal name, not the
  4199 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  4200 
  4201 * Disposed old type and term read functions (Sign.read_def_typ,
  4202 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  4203 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  4204 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  4205 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  4206 resort for legacy applications.
  4207 
  4208 * Disposed old declarations, tactics, tactic combinators that refer to
  4209 the simpset or claset of an implicit theory (such as Addsimps,
  4210 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  4211 embedded ML text, or local_simpset_of with a proper context passed as
  4212 explicit runtime argument.
  4213 
  4214 * Rules and tactics that read instantiations (read_instantiate,
  4215 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  4216 context, which is required for parsing and type-checking.  Moreover,
  4217 the variables are specified as plain indexnames, not string encodings
  4218 thereof.  INCOMPATIBILITY.
  4219 
  4220 * Generic Toplevel.add_hook interface allows to analyze the result of
  4221 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  4222 for theorem dependency output of transactions resulting in a new
  4223 theory state.
  4224 
  4225 * ML antiquotations: block-structured compilation context indicated by
  4226 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  4227 
  4228   @{binding name}                         - basic name binding
  4229   @{let ?pat = term}                      - term abbreviation (HO matching)
  4230   @{note name = fact}                     - fact abbreviation
  4231   @{thm fact}                             - singleton fact (with attributes)
  4232   @{thms fact}                            - general fact (with attributes)
  4233   @{lemma prop by method}                 - singleton goal
  4234   @{lemma prop by meth1 meth2}            - singleton goal
  4235   @{lemma prop1 ... propN by method}      - general goal
  4236   @{lemma prop1 ... propN by meth1 meth2} - general goal
  4237   @{lemma (open) ...}                     - open derivation
  4238 
  4239 
  4240 *** System ***
  4241 
  4242 * The Isabelle "emacs" tool provides a specific interface to invoke
  4243 Proof General / Emacs, with more explicit failure if that is not
  4244 installed (the old isabelle-interface script silently falls back on
  4245 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  4246 installation location of the Proof General distribution.
  4247 
  4248 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  4249 the Isabelle process into a JVM/Scala application.  See
  4250 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  4251 process wrapper has been discontinued.)
  4252 
  4253 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  4254 
  4255 * Various status messages (with exact source position information) are
  4256 emitted, if proper markup print mode is enabled.  This allows
  4257 user-interface components to provide detailed feedback on internal
  4258 prover operations.
  4259 
  4260 
  4261 
  4262 New in Isabelle2008 (June 2008)
  4263 -------------------------------
  4264 
  4265 *** General ***
  4266 
  4267 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  4268 and updated, with formally checked references as hyperlinks.
  4269 
  4270 * Theory loader: use_thy (and similar operations) no longer set the
  4271 implicit ML context, which was occasionally hard to predict and in
  4272 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  4273 provides a proper context already.
  4274 
  4275 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4276 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  4277 'use' within a theory file will do the job.
  4278 
  4279 * Name space merge now observes canonical order, i.e. the second space
  4280 is inserted into the first one, while existing entries in the first
  4281 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  4282 swap theory imports.
  4283 
  4284 * Syntax: symbol \<chi> is now considered a letter.  Potential
  4285 INCOMPATIBILITY in identifier syntax etc.
  4286 
  4287 * Outer syntax: string tokens no longer admit escaped white space,
  4288 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  4289 white space without escapes.
  4290 
  4291 * Outer syntax: string tokens may contain arbitrary character codes
  4292 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  4293 "foo_bar".
  4294 
  4295 
  4296 *** Pure ***
  4297 
  4298 * Context-dependent token translations.  Default setup reverts locally
  4299 fixed variables, and adds hilite markup for undeclared frees.
  4300 
  4301 * Unused theorems can be found using the new command 'unused_thms'.
  4302 There are three ways of invoking it:
  4303 
  4304 (1) unused_thms
  4305      Only finds unused theorems in the current theory.
  4306 
  4307 (2) unused_thms thy_1 ... thy_n -
  4308      Finds unused theorems in the current theory and all of its ancestors,
  4309      excluding the theories thy_1 ... thy_n and all of their ancestors.
  4310 
  4311 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  4312      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  4313      their ancestors, excluding the theories thy_1 ... thy_n and all of
  4314      their ancestors.
  4315 
  4316 In order to increase the readability of the list produced by
  4317 unused_thms, theorems that have been created by a particular instance
  4318 of a theory command such as 'inductive' or 'function' are considered
  4319 to belong to the same "group", meaning that if at least one theorem in
  4320 this group is used, the other theorems in the same group are no longer
  4321 reported as unused.  Moreover, if all theorems in the group are
  4322 unused, only one theorem in the group is displayed.
  4323 
  4324 Note that proof objects have to be switched on in order for
  4325 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  4326 usually the case when using Proof General with the default settings).
  4327 
  4328 * Authentic naming of facts disallows ad-hoc overwriting of previous
  4329 theorems within the same name space.  INCOMPATIBILITY, need to remove
  4330 duplicate fact bindings, or even accidental fact duplications.  Note
  4331 that tools may maintain dynamically scoped facts systematically, using
  4332 PureThy.add_thms_dynamic.
  4333 
  4334 * Command 'hide' now allows to hide from "fact" name space as well.
  4335 
  4336 * Eliminated destructive theorem database, simpset, claset, and
  4337 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  4338 update of theories within ML code.
  4339 
  4340 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  4341 INCOMPATIBILITY, object-logics depending on former Pure require
  4342 additional setup PureThy.old_appl_syntax_setup; object-logics
  4343 depending on former CPure need to refer to Pure.
  4344 
  4345 * Commands 'use' and 'ML' are now purely functional, operating on
  4346 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  4347 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  4348 INCOMPATIBILITY.
  4349 
  4350 * Command 'setup': discontinued implicit version with ML reference.
  4351 
  4352 * Instantiation target allows for simultaneous specification of class
  4353 instance operations together with an instantiation proof.
  4354 Type-checking phase allows to refer to class operations uniformly.
  4355 See src/HOL/Complex/Complex.thy for an Isar example and
  4356 src/HOL/Library/Eval.thy for an ML example.
  4357 
  4358 * Indexing of literal facts: be more serious about including only
  4359 facts from the visible specification/proof context, but not the
  4360 background context (locale etc.).  Affects `prop` notation and method
  4361 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  4362 situations.
  4363 
  4364 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  4365 "(open)" option, which used to expose internal bound variables to the
  4366 proof text.
  4367 
  4368 * Isar statements: removed obsolete case "rule_context".
  4369 INCOMPATIBILITY, better use explicit fixes/assumes.
  4370 
  4371 * Locale proofs: default proof step now includes 'unfold_locales';
  4372 hence 'proof' without argument may be used to unfold locale
  4373 predicates.
  4374 
  4375 
  4376 *** Document preparation ***
  4377 
  4378 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  4379 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  4380 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  4381 spot); renamed link color from "darkblue" to "linkcolor" (default
  4382 value unchanged, can be redefined via \definecolor); no longer sets
  4383 "a4paper" option (unnecessary or even intrusive).
  4384 
  4385 * Antiquotation @{lemma A method} proves proposition A by the given
  4386 method (either a method name or a method name plus (optional) method
  4387 arguments in parentheses) and prints A just like @{prop A}.
  4388 
  4389 
  4390 *** HOL ***
  4391 
  4392 * New primrec package.  Specification syntax conforms in style to
  4393 definition/function/....  No separate induction rule is provided.  The
  4394 "primrec" command distinguishes old-style and new-style specifications
  4395 by syntax.  The former primrec package is now named OldPrimrecPackage.
  4396 When adjusting theories, beware: constants stemming from new-style
  4397 primrec specifications have authentic syntax.
  4398 
  4399 * Metis prover is now an order of magnitude faster, and also works
  4400 with multithreading.
  4401 
  4402 * Metis: the maximum number of clauses that can be produced from a
  4403 theorem is now given by the attribute max_clauses.  Theorems that
  4404 exceed this number are ignored, with a warning printed.
  4405 
  4406 * Sledgehammer no longer produces structured proofs by default. To
  4407 enable, declare [[sledgehammer_full = true]].  Attributes
  4408 reconstruction_modulus, reconstruction_sorts renamed
  4409 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  4410 
  4411 * Method "induct_scheme" derives user-specified induction rules
  4412 from well-founded induction and completeness of patterns. This factors
  4413 out some operations that are done internally by the function package
  4414 and makes them available separately.  See
  4415 src/HOL/ex/Induction_Scheme.thy for examples.
  4416 
  4417 * More flexible generation of measure functions for termination
  4418 proofs: Measure functions can be declared by proving a rule of the
  4419 form "is_measure f" and giving it the [measure_function] attribute.
  4420 The "is_measure" predicate is logically meaningless (always true), and
  4421 just guides the heuristic.  To find suitable measure functions, the
  4422 termination prover sets up the goal "is_measure ?f" of the appropriate
  4423 type and generates all solutions by prolog-style backwards proof using
  4424 the declared rules.
  4425 
  4426 This setup also deals with rules like 
  4427 
  4428   "is_measure f ==> is_measure (list_size f)"
  4429 
  4430 which accommodates nested datatypes that recurse through lists.
  4431 Similar rules are predeclared for products and option types.
  4432 
  4433 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  4434 
  4435   INCOMPATIBILITIES:
  4436 
  4437   - Definitions of overloaded constants on sets have to be replaced by
  4438     definitions on => and bool.
  4439 
  4440   - Some definitions of overloaded operators on sets can now be proved
  4441     using the definitions of the operators on => and bool.  Therefore,
  4442     the following theorems have been renamed:
  4443 
  4444       subset_def   -> subset_eq
  4445       psubset_def  -> psubset_eq
  4446       set_diff_def -> set_diff_eq
  4447       Compl_def    -> Compl_eq
  4448       Sup_set_def  -> Sup_set_eq
  4449       Inf_set_def  -> Inf_set_eq
  4450       sup_set_def  -> sup_set_eq
  4451       inf_set_def  -> inf_set_eq
  4452 
  4453   - Due to the incompleteness of the HO unification algorithm, some
  4454     rules such as subst may require manual instantiation, if some of
  4455     the unknowns in the rule is a set.
  4456 
  4457   - Higher order unification and forward proofs:
  4458     The proof pattern
  4459 
  4460       have "P (S::'a set)" <...>
  4461       then have "EX S. P S" ..
  4462 
  4463     no longer works (due to the incompleteness of the HO unification
  4464     algorithm) and must be replaced by the pattern
  4465 
  4466       have "EX S. P S"
  4467       proof
  4468         show "P S" <...>
  4469       qed
  4470 
  4471   - Calculational reasoning with subst (or similar rules):
  4472     The proof pattern
  4473 
  4474       have "P (S::'a set)" <...>
  4475       also have "S = T" <...>
  4476       finally have "P T" .
  4477 
  4478     no longer works (for similar reasons as the previous example) and
  4479     must be replaced by something like
  4480 
  4481       have "P (S::'a set)" <...>
  4482       moreover have "S = T" <...>
  4483       ultimately have "P T" by simp
  4484 
  4485   - Tactics or packages written in ML code:
  4486     Code performing pattern matching on types via
  4487 
  4488       Type ("set", [T]) => ...
  4489 
  4490     must be rewritten. Moreover, functions like strip_type or
  4491     binder_types no longer return the right value when applied to a
  4492     type of the form
  4493 
  4494       T1 => ... => Tn => U => bool
  4495 
  4496     rather than
  4497 
  4498       T1 => ... => Tn => U set
  4499 
  4500 * Merged theories Wellfounded_Recursion, Accessible_Part and
  4501 Wellfounded_Relations to theory Wellfounded.
  4502 
  4503 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  4504 
  4505 * Class finite no longer treats UNIV as class parameter.  Use class
  4506 enum from theory Library/Enum instead to achieve a similar effect.
  4507 INCOMPATIBILITY.
  4508 
  4509 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  4510 and "Cons".  INCOMPATIBILITY.
  4511 
  4512 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  4513 Potential INCOMPATIBILITY.
  4514 
  4515 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  4516 injective_fst_snd removed, use split_eta and prod_eqI instead.
  4517 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  4518 
  4519 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  4520 the same name in theory Orderings:
  4521 
  4522   less_trans
  4523   less_linear
  4524   le_imp_less_or_eq
  4525   le_less_trans
  4526   less_le_trans
  4527   less_not_sym
  4528   less_asym
  4529 
  4530 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  4531 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  4532 and different variable names.
  4533 
  4534 * Library/Option_ord.thy: Canonical order on option type.
  4535 
  4536 * Library/RBT.thy: Red-black trees, an efficient implementation of
  4537 finite maps.
  4538 
  4539 * Library/Countable.thy: Type class for countable types.
  4540 
  4541 * Theory Int: The representation of numerals has changed.  The infix
  4542 operator BIT and the bit datatype with constructors B0 and B1 have
  4543 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  4544 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  4545 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  4546 accordingly.
  4547 
  4548 * Theory Nat: definition of <= and < on natural numbers no longer
  4549 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  4550 le_def and less_def have disappeared.  Consider lemmas not_less
  4551 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  4552 
  4553 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  4554 (whose purpose mainly is for various fold_set functionals) have been
  4555 abandoned in favor of the existing algebraic classes
  4556 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  4557 lower_semilattice (resp. upper_semilattice) and linorder.
  4558 INCOMPATIBILITY.
  4559 
  4560 * Theory Transitive_Closure: induct and cases rules now declare proper
  4561 case_names ("base" and "step").  INCOMPATIBILITY.
  4562 
  4563 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  4564 lattices.  The form set-specific version is available as
  4565 Inductive.lfp_ordinal_induct_set.
  4566 
  4567 * Renamed theorems "power.simps" to "power_int.simps".
  4568 INCOMPATIBILITY.
  4569 
  4570 * Class semiring_div provides basic abstract properties of semirings
  4571 with division and modulo operations.  Subsumes former class dvd_mod.
  4572 
  4573 * Merged theories IntDef, Numeral and IntArith into unified theory
  4574 Int.  INCOMPATIBILITY.
  4575 
  4576 * Theory Library/Code_Index: type "index" now represents natural
  4577 numbers rather than integers.  INCOMPATIBILITY.
  4578 
  4579 * New class "uminus" with operation "uminus" (split of from class
  4580 "minus" which now only has operation "minus", binary).
  4581 INCOMPATIBILITY.
  4582 
  4583 * Constants "card", "internal_split", "option_map" now with authentic
  4584 syntax.  INCOMPATIBILITY.
  4585 
  4586 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  4587 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  4588 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  4589 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  4590 Sup_set_def, le_def, less_def, option_map_def now with object
  4591 equality.  INCOMPATIBILITY.
  4592 
  4593 * Records. Removed K_record, and replaced it by pure lambda term
  4594 %x. c. The simplifier setup is now more robust against eta expansion.
  4595 INCOMPATIBILITY: in cases explicitly referring to K_record.
  4596 
  4597 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  4598 
  4599 * Library/ListVector: new theory of arithmetic vector operations.
  4600 
  4601 * Library/Order_Relation: new theory of various orderings as sets of
  4602 pairs.  Defines preorders, partial orders, linear orders and
  4603 well-orders on sets and on types.
  4604 
  4605 
  4606 *** ZF ***
  4607 
  4608 * Renamed some theories to allow to loading both ZF and HOL in the
  4609 same session:
  4610 
  4611   Datatype  -> Datatype_ZF
  4612   Inductive -> Inductive_ZF
  4613   Int       -> Int_ZF
  4614   IntDiv    -> IntDiv_ZF
  4615   Nat       -> Nat_ZF
  4616   List      -> List_ZF
  4617   Main      -> Main_ZF
  4618 
  4619 INCOMPATIBILITY: ZF theories that import individual theories below
  4620 Main might need to be adapted.  Regular theory Main is still
  4621 available, as trivial extension of Main_ZF.
  4622 
  4623 
  4624 *** ML ***
  4625 
  4626 * ML within Isar: antiquotation @{const name} or @{const
  4627 name(typargs)} produces statically-checked Const term.
  4628 
  4629 * Functor NamedThmsFun: data is available to the user as dynamic fact
  4630 (of the same name).  Removed obsolete print command.
  4631 
  4632 * Removed obsolete "use_legacy_bindings" function.
  4633 
  4634 * The ``print mode'' is now a thread-local value derived from a global
  4635 template (the former print_mode reference), thus access becomes
  4636 non-critical.  The global print_mode reference is for session
  4637 management only; user-code should use print_mode_value,
  4638 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  4639 
  4640 * Functions system/system_out provide a robust way to invoke external
  4641 shell commands, with propagation of interrupts (requires Poly/ML
  4642 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  4643 
  4644 
  4645 *** System ***
  4646 
  4647 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  4648 in accordance with Proof General 3.7, which prefers GNU emacs.
  4649 
  4650 * isatool tty runs Isabelle process with plain tty interaction;
  4651 optional line editor may be specified via ISABELLE_LINE_EDITOR
  4652 setting, the default settings attempt to locate "ledit" and "rlwrap".
  4653 
  4654 * isatool browser now works with Cygwin as well, using general
  4655 "javapath" function defined in Isabelle process environment.
  4656 
  4657 * YXML notation provides a simple and efficient alternative to
  4658 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  4659 isatool yxml as described in the Isabelle system manual.
  4660 
  4661 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  4662 provides general wrapper for managing an Isabelle process in a robust
  4663 fashion, with ``cooked'' output from stdin/stderr.
  4664 
  4665 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  4666 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  4667 
  4668 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  4669 way of changing the user's settings is via
  4670 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  4671 script.
  4672 
  4673 * Multithreading.max_threads := 0 refers to the number of actual CPU
  4674 cores of the underlying machine, which is a good starting point for
  4675 optimal performance tuning.  The corresponding usedir option -M allows
  4676 "max" as an alias for "0".  WARNING: does not work on certain versions
  4677 of Mac OS (with Poly/ML 5.1).
  4678 
  4679 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  4680 adverse effect of Isabelle flooding interactive front-ends (notably
  4681 ProofGeneral / XEmacs).
  4682 
  4683 
  4684 
  4685 New in Isabelle2007 (November 2007)
  4686 -----------------------------------
  4687 
  4688 *** General ***
  4689 
  4690 * More uniform information about legacy features, notably a
  4691 warning/error of "Legacy feature: ...", depending on the state of the
  4692 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  4693 legacy features will disappear eventually.
  4694 
  4695 * Theory syntax: the header format ``theory A = B + C:'' has been
  4696 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  4697 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  4698 
  4699 * Theory syntax: the old non-Isar theory file format has been
  4700 discontinued altogether.  Note that ML proof scripts may still be used
  4701 with Isar theories; migration is usually quite simple with the ML
  4702 function use_legacy_bindings.  INCOMPATIBILITY.
  4703 
  4704 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  4705 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  4706 quotes.
  4707 
  4708 * Theory loader: be more serious about observing the static theory
  4709 header specifications (including optional directories), but not the
  4710 accidental file locations of previously successful loads.  The strict
  4711 update policy of former update_thy is now already performed by
  4712 use_thy, so the former has been removed; use_thys updates several
  4713 theories simultaneously, just as 'imports' within a theory header
  4714 specification, but without merging the results.  Potential
  4715 INCOMPATIBILITY: may need to refine theory headers and commands
  4716 ROOT.ML which depend on load order.
  4717 
  4718 * Theory loader: optional support for content-based file
  4719 identification, instead of the traditional scheme of full physical
  4720 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  4721 (cf. the system manual).  The new scheme allows to work with
  4722 non-finished theories in persistent session images, such that source
  4723 files may be moved later on without requiring reloads.
  4724 
  4725 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4726 file (with the same base name as the theory) are considered a legacy
  4727 feature, which will disappear eventually. Even now, the theory loader
  4728 no longer maintains dependencies on such files.
  4729 
  4730 * Syntax: the scope for resolving ambiguities via type-inference is
  4731 now limited to individual terms, instead of whole simultaneous
  4732 specifications as before. This greatly reduces the complexity of the
  4733 syntax module and improves flexibility by separating parsing and
  4734 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  4735 'fixes' etc.) are required in rare situations.
  4736 
  4737 * Syntax: constants introduced by new-style packages ('definition',
  4738 'abbreviation' etc.) are passed through the syntax module in
  4739 ``authentic mode''. This means that associated mixfix annotations
  4740 really stick to such constants, independently of potential name space
  4741 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  4742 trees are represented slightly differently, may need to adapt syntax
  4743 translations accordingly. Use CONST marker in 'translations' and
  4744 @{const_syntax} antiquotation in 'parse_translation' etc.
  4745 
  4746 * Legacy goal package: reduced interface to the bare minimum required
  4747 to keep existing proof scripts running.  Most other user-level
  4748 functions are now part of the OldGoals structure, which is *not* open
  4749 by default (consider isatool expandshort before open OldGoals).
  4750 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  4751 these tend to cause confusion about the actual goal (!) context being
  4752 used here, which is not necessarily the same as the_context().
  4753 
  4754 * Command 'find_theorems': supports "*" wild-card in "name:"
  4755 criterion; "with_dups" option.  Certain ProofGeneral versions might
  4756 support a specific search form (see ProofGeneral/CHANGES).
  4757 
  4758 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  4759 by default, which means that "prems" (and also "fixed variables") are
  4760 suppressed from proof state output.  Note that the ProofGeneral
  4761 settings mechanism allows to change and save options persistently, but
  4762 older versions of Isabelle will fail to start up if a negative prems
  4763 limit is imposed.
  4764 
  4765 * Local theory targets may be specified by non-nested blocks of
  4766 ``context/locale/class ... begin'' followed by ``end''.  The body may
  4767 contain definitions, theorems etc., including any derived mechanism
  4768 that has been implemented on top of these primitives.  This concept
  4769 generalizes the existing ``theorem (in ...)'' towards more versatility
  4770 and scalability.
  4771 
  4772 * Proof General interface: proper undo of final 'end' command;
  4773 discontinued Isabelle/classic mode (ML proof scripts).
  4774 
  4775 
  4776 *** Document preparation ***
  4777 
  4778 * Added antiquotation @{theory name} which prints the given name,
  4779 after checking that it refers to a valid ancestor theory in the
  4780 current context.
  4781 
  4782 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  4783 check the given source text as ML type/structure, printing verbatim.
  4784 
  4785 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  4786 "c args == rhs" given in the current context.  (Any number of
  4787 arguments may be given on the LHS.)
  4788 
  4789 
  4790 *** Pure ***
  4791 
  4792 * The 'class' package offers a combination of axclass and locale to
  4793 achieve Haskell-like type classes in Isabelle.  Definitions and
  4794 theorems within a class context produce both relative results (with
  4795 implicit parameters according to the locale context), and polymorphic
  4796 constants with qualified polymorphism (according to the class
  4797 context).  Within the body context of a 'class' target, a separate
  4798 syntax layer ("user space type system") takes care of converting
  4799 between global polymorphic consts and internal locale representation.
  4800 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  4801 "isatool doc classes" provides a tutorial.
  4802 
  4803 * Generic code generator framework allows to generate executable
  4804 code for ML and Haskell (including Isabelle classes).  A short usage
  4805 sketch:
  4806 
  4807     internal compilation:
  4808         export_code <list of constants (term syntax)> in SML
  4809     writing SML code to a file:
  4810         export_code <list of constants (term syntax)> in SML <filename>
  4811     writing OCaml code to a file:
  4812         export_code <list of constants (term syntax)> in OCaml <filename>
  4813     writing Haskell code to a bunch of files:
  4814         export_code <list of constants (term syntax)> in Haskell <filename>
  4815 
  4816     evaluating closed propositions to True/False using code generation:
  4817         method ``eval''
  4818 
  4819 Reasonable default setup of framework in HOL.
  4820 
  4821 Theorem attributs for selecting and transforming function equations theorems:
  4822 
  4823     [code fun]:        select a theorem as function equation for a specific constant
  4824     [code fun del]:    deselect a theorem as function equation for a specific constant
  4825     [code inline]:     select an equation theorem for unfolding (inlining) in place
  4826     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  4827 
  4828 User-defined serializations (target in {SML, OCaml, Haskell}):
  4829 
  4830     code_const <and-list of constants (term syntax)>
  4831       {(target) <and-list of const target syntax>}+
  4832 
  4833     code_type <and-list of type constructors>
  4834       {(target) <and-list of type target syntax>}+
  4835 
  4836     code_instance <and-list of instances>
  4837       {(target)}+
  4838         where instance ::= <type constructor> :: <class>
  4839 
  4840     code_class <and_list of classes>
  4841       {(target) <and-list of class target syntax>}+
  4842         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  4843 
  4844 code_instance and code_class only are effective to target Haskell.
  4845 
  4846 For example usage see src/HOL/ex/Codegenerator.thy and
  4847 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  4848 generation from Isabelle/HOL theories is available via "isatool doc
  4849 codegen".
  4850 
  4851 * Code generator: consts in 'consts_code' Isar commands are now
  4852 referred to by usual term syntax (including optional type
  4853 annotations).
  4854 
  4855 * Command 'no_translations' removes translation rules from theory
  4856 syntax.
  4857 
  4858 * Overloaded definitions are now actually checked for acyclic
  4859 dependencies.  The overloading scheme is slightly more general than
  4860 that of Haskell98, although Isabelle does not demand an exact
  4861 correspondence to type class and instance declarations.
  4862 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4863 exotic versions of overloading -- at the discretion of the user!
  4864 
  4865 Polymorphic constants are represented via type arguments, i.e. the
  4866 instantiation that matches an instance against the most general
  4867 declaration given in the signature.  For example, with the declaration
  4868 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4869 as c(nat).  Overloading is essentially simultaneous structural
  4870 recursion over such type arguments.  Incomplete specification patterns
  4871 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4872 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4873 Command 'print_theory' outputs the normalized system of recursive
  4874 equations, see section "definitions".
  4875 
  4876 * Configuration options are maintained within the theory or proof
  4877 context (with name and type bool/int/string), providing a very simple
  4878 interface to a poor-man's version of general context data.  Tools may
  4879 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4880 these values using Config.get etc.  Users may change options via an
  4881 associated attribute of the same name.  This form of context
  4882 declaration works particularly well with commands 'declare' or
  4883 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4884 very easy to avoid global references, which would not observe Isar
  4885 toplevel undo/redo and fail to work with multithreading.
  4886 
  4887 Various global ML references of Pure and HOL have been turned into
  4888 configuration options:
  4889 
  4890   Unify.search_bound		unify_search_bound
  4891   Unify.trace_bound		unify_trace_bound
  4892   Unify.trace_simp		unify_trace_simp
  4893   Unify.trace_types		unify_trace_types
  4894   Simplifier.simp_depth_limit	simp_depth_limit
  4895   Blast.depth_limit		blast_depth_limit
  4896   DatatypeProp.dtK		datatype_distinctness_limit
  4897   fast_arith_neq_limit  	fast_arith_neq_limit
  4898   fast_arith_split_limit	fast_arith_split_limit
  4899 
  4900 * Named collections of theorems may be easily installed as context
  4901 data using the functor NamedThmsFun (see also
  4902 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4903 attributes; there is also a toplevel print command.  This facility is
  4904 just a common case of general context data, which is the preferred way
  4905 for anything more complex than just a list of facts in canonical
  4906 order.
  4907 
  4908 * Isar: command 'declaration' augments a local theory by generic
  4909 declaration functions written in ML.  This enables arbitrary content
  4910 being added to the context, depending on a morphism that tells the
  4911 difference of the original declaration context wrt. the application
  4912 context encountered later on.
  4913 
  4914 * Isar: proper interfaces for simplification procedures.  Command
  4915 'simproc_setup' declares named simprocs (with match patterns, and body
  4916 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4917 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4918 
  4919 * Isar: an extra pair of brackets around attribute declarations
  4920 abbreviates a theorem reference involving an internal dummy fact,
  4921 which will be ignored later --- only the effect of the attribute on
  4922 the background context will persist.  This form of in-place
  4923 declarations is particularly useful with commands like 'declare' and
  4924 'using', for example ``have A using [[simproc a]] by simp''.
  4925 
  4926 * Isar: method "assumption" (and implicit closing of subproofs) now
  4927 takes simple non-atomic goal assumptions into account: after applying
  4928 an assumption as a rule the resulting subgoals are solved by atomic
  4929 assumption steps.  This is particularly useful to finish 'obtain'
  4930 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4931 without referring to the original premise "!!x. P x ==> thesis" in the
  4932 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4933 more permissive.
  4934 
  4935 * Isar: implicit use of prems from the Isar proof context is
  4936 considered a legacy feature.  Common applications like ``have A .''
  4937 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4938 referencing facts explicitly here improves readability and
  4939 maintainability of proof texts.
  4940 
  4941 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4942 the obtained context from the course of reasoning!  For example:
  4943 
  4944   assume "EX x y. A x & B y"   -- "any previous fact"
  4945   then guess x and y by clarify
  4946 
  4947 This technique is potentially adventurous, depending on the facts and
  4948 proof tools being involved here.
  4949 
  4950 * Isar: known facts from the proof context may be specified as literal
  4951 propositions, using ASCII back-quote syntax.  This works wherever
  4952 named facts used to be allowed so far, in proof commands, proof
  4953 methods, attributes etc.  Literal facts are retrieved from the context
  4954 according to unification of type and term parameters.  For example,
  4955 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4956 theorems in the current context, then these are valid literal facts:
  4957 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4958 
  4959 There is also a proof method "fact" which does the same composition
  4960 for explicit goal states, e.g. the following proof texts coincide with
  4961 certain special cases of literal facts:
  4962 
  4963   have "A" by fact                 ==  note `A`
  4964   have "A ==> B" by fact           ==  note `A ==> B`
  4965   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4966   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4967 
  4968 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4969 outer syntax.  Thus symbolic identifiers may be used without
  4970 additional white space in declarations like this: ``assume *: A''.
  4971 
  4972 * Isar: 'print_facts' prints all local facts of the current context,
  4973 both named and unnamed ones.
  4974 
  4975 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4976 
  4977   def x == "t" and y == "u"
  4978 
  4979 * Isar: added command 'unfolding', which is structurally similar to
  4980 'using', but affects both the goal state and facts by unfolding given
  4981 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4982 'unfolded' attribute may be replaced by first-class proof text.
  4983 
  4984 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4985 and command 'unfolding' now all support object-level equalities
  4986 (potentially conditional).  The underlying notion of rewrite rule is
  4987 analogous to the 'rule_format' attribute, but *not* that of the
  4988 Simplifier (which is usually more generous).
  4989 
  4990 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4991 premises of a theorem by n. Useful in conjunction with drule.
  4992 
  4993 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4994 method expression within a sandbox consisting of the first N
  4995 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4996 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4997 simplifies all new goals that emerge from applying rule foo to the
  4998 originally first one.
  4999 
  5000 * Isar: schematic goals are no longer restricted to higher-order
  5001 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  5002 expected.
  5003 
  5004 * Isar: the conclusion of a long theorem statement is now either
  5005 'shows' (a simultaneous conjunction, as before), or 'obtains'
  5006 (essentially a disjunction of cases with local parameters and
  5007 assumptions).  The latter allows to express general elimination rules
  5008 adequately; in this notation common elimination rules look like this:
  5009 
  5010   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  5011     assumes "EX x. P x"
  5012     obtains x where "P x"
  5013 
  5014   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  5015     assumes "A & B"
  5016     obtains A and B
  5017 
  5018   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  5019     assumes "A | B"
  5020     obtains
  5021       A
  5022     | B
  5023 
  5024 The subsequent classical rules even refer to the formal "thesis"
  5025 explicitly:
  5026 
  5027   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  5028     obtains "~ thesis"
  5029 
  5030   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  5031     obtains "thesis ==> something"
  5032 
  5033 The actual proof of an 'obtains' statement is analogous to that of the
  5034 Isar proof element 'obtain', only that there may be several cases.
  5035 Optional case names may be specified in parentheses; these will be
  5036 available both in the present proof and as annotations in the
  5037 resulting rule, for later use with the 'cases' method (cf. attribute
  5038 case_names).
  5039 
  5040 * Isar: the assumptions of a long theorem statement are available as
  5041 "assms" fact in the proof context.  This is more appropriate than the
  5042 (historical) "prems", which refers to all assumptions of the current
  5043 context, including those from the target locale, proof body etc.
  5044 
  5045 * Isar: 'print_statement' prints theorems from the current theory or
  5046 proof context in long statement form, according to the syntax of a
  5047 top-level lemma.
  5048 
  5049 * Isar: 'obtain' takes an optional case name for the local context
  5050 introduction rule (default "that").
  5051 
  5052 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  5053 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  5054 to occur.
  5055 
  5056 * Pure: syntax "CONST name" produces a fully internalized constant
  5057 according to the current context.  This is particularly useful for
  5058 syntax translations that should refer to internal constant
  5059 representations independently of name spaces.
  5060 
  5061 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  5062 instead of "FOO ". This allows multiple binder declarations to coexist
  5063 in the same context.  INCOMPATIBILITY.
  5064 
  5065 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  5066 primitive that also works in a locale context (both for constants and
  5067 fixed variables). Type declaration and internal syntactic representation
  5068 of given constants retrieved from the context. Likewise, the
  5069 'no_notation' command allows to remove given syntax annotations from the
  5070 current context.
  5071 
  5072 * Isar/locales: new derived specification elements 'axiomatization',
  5073 'definition', 'abbreviation', which support type-inference, admit
  5074 object-level specifications (equality, equivalence).  See also the
  5075 isar-ref manual.  Examples:
  5076 
  5077   axiomatization
  5078     eq  (infix "===" 50) where
  5079     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  5080 
  5081   definition "f x y = x + y + 1"
  5082   definition g where "g x = f x x"
  5083 
  5084   abbreviation
  5085     neq  (infix "=!=" 50) where
  5086     "x =!= y == ~ (x === y)"
  5087 
  5088 These specifications may be also used in a locale context.  Then the
  5089 constants being introduced depend on certain fixed parameters, and the
  5090 constant name is qualified by the locale base name.  An internal
  5091 abbreviation takes care for convenient input and output, making the
  5092 parameters implicit and using the original short name.  See also
  5093 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  5094 entities from a monomorphic theory.
  5095 
  5096 Presently, abbreviations are only available 'in' a target locale, but
  5097 not inherited by general import expressions.  Also note that
  5098 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  5099 'translations' in common applications.  The "no_abbrevs" print mode
  5100 prevents folding of abbreviations in term output.
  5101 
  5102 Concrete syntax is attached to specified constants in internal form,
  5103 independently of name spaces.  The parse tree representation is
  5104 slightly different -- use 'notation' instead of raw 'syntax', and
  5105 'translations' with explicit "CONST" markup to accommodate this.
  5106 
  5107 * Pure/Isar: unified syntax for new-style specification mechanisms
  5108 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  5109 full type inference and dummy patterns ("_").  For example:
  5110 
  5111   definition "K x _ = x"
  5112 
  5113   inductive conj for A B
  5114   where "A ==> B ==> conj A B"
  5115 
  5116 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  5117 the current context.  Print mode "no_abbrevs" prevents inversion of
  5118 abbreviations on output.
  5119 
  5120 * Isar/locales: improved parameter handling: use of locales "var" and
  5121 "struct" no longer necessary; - parameter renamings are no longer
  5122 required to be injective.  For example, this allows to define
  5123 endomorphisms as locale endom = homom mult mult h.
  5124 
  5125 * Isar/locales: changed the way locales with predicates are defined.
  5126 Instead of accumulating the specification, the imported expression is
  5127 now an interpretation.  INCOMPATIBILITY: different normal form of
  5128 locale expressions.  In particular, in interpretations of locales with
  5129 predicates, goals repesenting already interpreted fragments are not
  5130 removed automatically.  Use methods `intro_locales' and
  5131 `unfold_locales'; see below.
  5132 
  5133 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  5134 provide backward reasoning on locales predicates.  The methods are
  5135 aware of interpretations and discharge corresponding goals.
  5136 `intro_locales' is less aggressive then `unfold_locales' and does not
  5137 unfold predicates to assumptions.
  5138 
  5139 * Isar/locales: the order in which locale fragments are accumulated
  5140 has changed.  This enables to override declarations from fragments due
  5141 to interpretations -- for example, unwanted simp rules.
  5142 
  5143 * Isar/locales: interpretation in theories and proof contexts has been
  5144 extended.  One may now specify (and prove) equations, which are
  5145 unfolded in interpreted theorems.  This is useful for replacing
  5146 defined concepts (constants depending on locale parameters) by
  5147 concepts already existing in the target context.  Example:
  5148 
  5149   interpretation partial_order ["op <= :: [int, int] => bool"]
  5150     where "partial_order.less (op <=) (x::int) y = (x < y)"
  5151 
  5152 Typically, the constant `partial_order.less' is created by a
  5153 definition specification element in the context of locale
  5154 partial_order.
  5155 
  5156 * Method "induct": improved internal context management to support
  5157 local fixes and defines on-the-fly. Thus explicit meta-level
  5158 connectives !!  and ==> are rarely required anymore in inductive goals
  5159 (using object-logic connectives for this purpose has been long
  5160 obsolete anyway). Common proof patterns are explained in
  5161 src/HOL/Induct/Common_Patterns.thy, see also
  5162 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  5163 examples.
  5164 
  5165 * Method "induct": improved handling of simultaneous goals. Instead of
  5166 introducing object-level conjunction, the statement is now split into
  5167 several conclusions, while the corresponding symbolic cases are nested
  5168 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  5169 see src/HOL/Induct/Common_Patterns.thy, for example.
  5170 
  5171 * Method "induct": mutual induction rules are now specified as a list
  5172 of rule sharing the same induction cases. HOL packages usually provide
  5173 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  5174 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  5175 mutual induction rules differently, i.e. like this:
  5176 
  5177   (induct rule: foo_bar.inducts)
  5178   (induct set: foo bar)
  5179   (induct pred: foo bar)
  5180   (induct type: foo bar)
  5181 
  5182 The ML function ProjectRule.projections turns old-style rules into the
  5183 new format.
  5184 
  5185 * Method "coinduct": dual of induction, see
  5186 src/HOL/Library/Coinductive_List.thy for various examples.
  5187 
  5188 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  5189 considered a legacy feature.
  5190 
  5191 * Attribute "symmetric" produces result with standardized schematic
  5192 variables (index 0).  Potential INCOMPATIBILITY.
  5193 
  5194 * Simplifier: by default the simplifier trace only shows top level
  5195 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  5196 default. Thus there is less danger of being flooded by the trace. The
  5197 trace indicates where parts have been suppressed.
  5198   
  5199 * Provers/classical: removed obsolete classical version of elim_format
  5200 attribute; classical elim/dest rules are now treated uniformly when
  5201 manipulating the claset.
  5202 
  5203 * Provers/classical: stricter checks to ensure that supplied intro,
  5204 dest and elim rules are well-formed; dest and elim rules must have at
  5205 least one premise.
  5206 
  5207 * Provers/classical: attributes dest/elim/intro take an optional
  5208 weight argument for the rule (just as the Pure versions).  Weights are
  5209 ignored by automated tools, but determine the search order of single
  5210 rule steps.
  5211 
  5212 * Syntax: input syntax now supports dummy variable binding "%_. b",
  5213 where the body does not mention the bound variable.  Note that dummy
  5214 patterns implicitly depend on their context of bounds, which makes
  5215 "{_. _}" match any set comprehension as expected.  Potential
  5216 INCOMPATIBILITY -- parse translations need to cope with syntactic
  5217 constant "_idtdummy" in the binding position.
  5218 
  5219 * Syntax: removed obsolete syntactic constant "_K" and its associated
  5220 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  5221 for example "A -> B" => "Pi A (%_. B)".
  5222 
  5223 * Pure: 'class_deps' command visualizes the subclass relation, using
  5224 the graph browser tool.
  5225 
  5226 * Pure: 'print_theory' now suppresses certain internal declarations by
  5227 default; use '!' option for full details.
  5228 
  5229 
  5230 *** HOL ***
  5231 
  5232 * Method "metis" proves goals by applying the Metis general-purpose
  5233 resolution prover (see also http://gilith.com/software/metis/).
  5234 Examples are in the directory MetisExamples.  WARNING: the
  5235 Isabelle/HOL-Metis integration does not yet work properly with
  5236 multi-threading.
  5237   
  5238 * Command 'sledgehammer' invokes external automatic theorem provers as
  5239 background processes.  It generates calls to the "metis" method if
  5240 successful. These can be pasted into the proof.  Users do not have to
  5241 wait for the automatic provers to return.  WARNING: does not really
  5242 work with multi-threading.
  5243 
  5244 * New "auto_quickcheck" feature tests outermost goal statements for
  5245 potential counter-examples.  Controlled by ML references
  5246 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  5247 5000 milliseconds).  Fails silently if statements is outside of
  5248 executable fragment, or any other codgenerator problem occurs.
  5249 
  5250 * New constant "undefined" with axiom "undefined x = undefined".
  5251 
  5252 * Added class "HOL.eq", allowing for code generation with polymorphic
  5253 equality.
  5254 
  5255 * Some renaming of class constants due to canonical name prefixing in
  5256 the new 'class' package:
  5257 
  5258     HOL.abs ~> HOL.abs_class.abs
  5259     HOL.divide ~> HOL.divide_class.divide
  5260     0 ~> HOL.zero_class.zero
  5261     1 ~> HOL.one_class.one
  5262     op + ~> HOL.plus_class.plus
  5263     op - ~> HOL.minus_class.minus
  5264     uminus ~> HOL.minus_class.uminus
  5265     op * ~> HOL.times_class.times
  5266     op < ~> HOL.ord_class.less
  5267     op <= > HOL.ord_class.less_eq
  5268     Nat.power ~> Power.power_class.power
  5269     Nat.size ~> Nat.size_class.size
  5270     Numeral.number_of ~> Numeral.number_class.number_of
  5271     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  5272     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  5273     Orderings.min ~> Orderings.ord_class.min
  5274     Orderings.max ~> Orderings.ord_class.max
  5275     Divides.op div ~> Divides.div_class.div
  5276     Divides.op mod ~> Divides.div_class.mod
  5277     Divides.op dvd ~> Divides.div_class.dvd
  5278 
  5279 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  5280 
  5281 a) User-defined constants using any of the names "plus", "minus",
  5282 "times", "less" or "less_eq". The standard syntax translations for
  5283 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  5284 names.
  5285 
  5286 b) Variables named "plus", "minus", "times", "less", "less_eq"
  5287 INCOMPATIBILITY: use more specific names.
  5288 
  5289 c) Permutative equations (e.g. "a + b = b + a")
  5290 Since the change of names also changes the order of terms, permutative
  5291 rewrite rules may get applied in a different order. Experience shows
  5292 that this is rarely the case (only two adaptions in the whole Isabelle
  5293 distribution).  INCOMPATIBILITY: rewrite proofs
  5294 
  5295 d) ML code directly refering to constant names
  5296 This in general only affects hand-written proof tactics, simprocs and
  5297 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  5298 Consider using @{const_name} antiquotation.
  5299 
  5300 * New class "default" with associated constant "default".
  5301 
  5302 * Function "sgn" is now overloaded and available on int, real, complex
  5303 (and other numeric types), using class "sgn".  Two possible defs of
  5304 sgn are given as equational assumptions in the classes sgn_if and
  5305 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  5306 INCOMPATIBILITY.
  5307 
  5308 * Locale "partial_order" now unified with class "order" (cf. theory
  5309 Orderings), added parameter "less".  INCOMPATIBILITY.
  5310 
  5311 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  5312 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  5313 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  5314 
  5315 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  5316 changed order of proof goals in instance proofs.
  5317 
  5318 * The transitivity reasoner for partial and linear orders is set up
  5319 for classes "order" and "linorder".  Instances of the reasoner are available
  5320 in all contexts importing or interpreting the corresponding locales.
  5321 Method "order" invokes the reasoner separately; the reasoner
  5322 is also integrated with the Simplifier as a solver.  Diagnostic
  5323 command 'print_orders' shows the available instances of the reasoner
  5324 in the current context.
  5325 
  5326 * Localized monotonicity predicate in theory "Orderings"; integrated
  5327 lemmas max_of_mono and min_of_mono with this predicate.
  5328 INCOMPATIBILITY.
  5329 
  5330 * Formulation of theorem "dense" changed slightly due to integration
  5331 with new class dense_linear_order.
  5332 
  5333 * Uniform lattice theory development in HOL.
  5334 
  5335     constants "meet" and "join" now named "inf" and "sup"
  5336     constant "Meet" now named "Inf"
  5337 
  5338     classes "meet_semilorder" and "join_semilorder" now named
  5339       "lower_semilattice" and "upper_semilattice"
  5340     class "lorder" now named "lattice"
  5341     class "comp_lat" now named "complete_lattice"
  5342 
  5343     Instantiation of lattice classes allows explicit definitions
  5344     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  5345 
  5346   INCOMPATIBILITY.  Theorem renames:
  5347 
  5348     meet_left_le            ~> inf_le1
  5349     meet_right_le           ~> inf_le2
  5350     join_left_le            ~> sup_ge1
  5351     join_right_le           ~> sup_ge2
  5352     meet_join_le            ~> inf_sup_ord
  5353     le_meetI                ~> le_infI
  5354     join_leI                ~> le_supI
  5355     le_meet                 ~> le_inf_iff
  5356     le_join                 ~> ge_sup_conv
  5357     meet_idempotent         ~> inf_idem
  5358     join_idempotent         ~> sup_idem
  5359     meet_comm               ~> inf_commute
  5360     join_comm               ~> sup_commute
  5361     meet_leI1               ~> le_infI1
  5362     meet_leI2               ~> le_infI2
  5363     le_joinI1               ~> le_supI1
  5364     le_joinI2               ~> le_supI2
  5365     meet_assoc              ~> inf_assoc
  5366     join_assoc              ~> sup_assoc
  5367     meet_left_comm          ~> inf_left_commute
  5368     meet_left_idempotent    ~> inf_left_idem
  5369     join_left_comm          ~> sup_left_commute
  5370     join_left_idempotent    ~> sup_left_idem
  5371     meet_aci                ~> inf_aci
  5372     join_aci                ~> sup_aci
  5373     le_def_meet             ~> le_iff_inf
  5374     le_def_join             ~> le_iff_sup
  5375     join_absorp2            ~> sup_absorb2
  5376     join_absorp1            ~> sup_absorb1
  5377     meet_absorp1            ~> inf_absorb1
  5378     meet_absorp2            ~> inf_absorb2
  5379     meet_join_absorp        ~> inf_sup_absorb
  5380     join_meet_absorp        ~> sup_inf_absorb
  5381     distrib_join_le         ~> distrib_sup_le
  5382     distrib_meet_le         ~> distrib_inf_le
  5383 
  5384     add_meet_distrib_left   ~> add_inf_distrib_left
  5385     add_join_distrib_left   ~> add_sup_distrib_left
  5386     is_join_neg_meet        ~> is_join_neg_inf
  5387     is_meet_neg_join        ~> is_meet_neg_sup
  5388     add_meet_distrib_right  ~> add_inf_distrib_right
  5389     add_join_distrib_right  ~> add_sup_distrib_right
  5390     add_meet_join_distribs  ~> add_sup_inf_distribs
  5391     join_eq_neg_meet        ~> sup_eq_neg_inf
  5392     meet_eq_neg_join        ~> inf_eq_neg_sup
  5393     add_eq_meet_join        ~> add_eq_inf_sup
  5394     meet_0_imp_0            ~> inf_0_imp_0
  5395     join_0_imp_0            ~> sup_0_imp_0
  5396     meet_0_eq_0             ~> inf_0_eq_0
  5397     join_0_eq_0             ~> sup_0_eq_0
  5398     neg_meet_eq_join        ~> neg_inf_eq_sup
  5399     neg_join_eq_meet        ~> neg_sup_eq_inf
  5400     join_eq_if              ~> sup_eq_if
  5401 
  5402     mono_meet               ~> mono_inf
  5403     mono_join               ~> mono_sup
  5404     meet_bool_eq            ~> inf_bool_eq
  5405     join_bool_eq            ~> sup_bool_eq
  5406     meet_fun_eq             ~> inf_fun_eq
  5407     join_fun_eq             ~> sup_fun_eq
  5408     meet_set_eq             ~> inf_set_eq
  5409     join_set_eq             ~> sup_set_eq
  5410     meet1_iff               ~> inf1_iff
  5411     meet2_iff               ~> inf2_iff
  5412     meet1I                  ~> inf1I
  5413     meet2I                  ~> inf2I
  5414     meet1D1                 ~> inf1D1
  5415     meet2D1                 ~> inf2D1
  5416     meet1D2                 ~> inf1D2
  5417     meet2D2                 ~> inf2D2
  5418     meet1E                  ~> inf1E
  5419     meet2E                  ~> inf2E
  5420     join1_iff               ~> sup1_iff
  5421     join2_iff               ~> sup2_iff
  5422     join1I1                 ~> sup1I1
  5423     join2I1                 ~> sup2I1
  5424     join1I1                 ~> sup1I1
  5425     join2I2                 ~> sup1I2
  5426     join1CI                 ~> sup1CI
  5427     join2CI                 ~> sup2CI
  5428     join1E                  ~> sup1E
  5429     join2E                  ~> sup2E
  5430 
  5431     is_meet_Meet            ~> is_meet_Inf
  5432     Meet_bool_def           ~> Inf_bool_def
  5433     Meet_fun_def            ~> Inf_fun_def
  5434     Meet_greatest           ~> Inf_greatest
  5435     Meet_lower              ~> Inf_lower
  5436     Meet_set_def            ~> Inf_set_def
  5437 
  5438     Sup_def                 ~> Sup_Inf
  5439     Sup_bool_eq             ~> Sup_bool_def
  5440     Sup_fun_eq              ~> Sup_fun_def
  5441     Sup_set_eq              ~> Sup_set_def
  5442 
  5443     listsp_meetI            ~> listsp_infI
  5444     listsp_meet_eq          ~> listsp_inf_eq
  5445 
  5446     meet_min                ~> inf_min
  5447     join_max                ~> sup_max
  5448 
  5449 * Added syntactic class "size"; overloaded constant "size" now has
  5450 type "'a::size ==> bool"
  5451 
  5452 * Internal reorganisation of `size' of datatypes: size theorems
  5453 "foo.size" are no longer subsumed by "foo.simps" (but are still
  5454 simplification rules by default!); theorems "prod.size" now named
  5455 "*.size".
  5456 
  5457 * Class "div" now inherits from class "times" rather than "type".
  5458 INCOMPATIBILITY.
  5459 
  5460 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  5461 Linorder etc.  have disappeared; operations defined in terms of
  5462 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  5463 
  5464 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  5465 
  5466 * HOL-Word: New extensive library and type for generic, fixed size
  5467 machine words, with arithmetic, bit-wise, shifting and rotating
  5468 operations, reflection into int, nat, and bool lists, automation for
  5469 linear arithmetic (by automatic reflection into nat or int), including
  5470 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  5471 arithmetic type classes, supporting automatic simplification of
  5472 numerals on all operations.
  5473 
  5474 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  5475 
  5476 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  5477 
  5478 * Code generator library theories:
  5479   - Code_Integer represents HOL integers by big integer literals in target
  5480     languages.
  5481   - Code_Char represents HOL characters by character literals in target
  5482     languages.
  5483   - Code_Char_chr like Code_Char, but also offers treatment of character
  5484     codes; includes Code_Integer.
  5485   - Executable_Set allows to generate code for finite sets using lists.
  5486   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  5487     denominator).
  5488   - Executable_Real implements a subset of real numbers, namly those
  5489     representable by rational numbers.
  5490   - Efficient_Nat implements natural numbers by integers, which in general will
  5491     result in higher efficency; pattern matching with 0/Suc is eliminated;
  5492     includes Code_Integer.
  5493   - Code_Index provides an additional datatype index which is mapped to
  5494     target-language built-in integers.
  5495   - Code_Message provides an additional datatype message_string which is isomorphic to
  5496     strings; messages are mapped to target-language strings.
  5497 
  5498 * New package for inductive predicates
  5499 
  5500   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  5501 
  5502     inductive
  5503       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5504       for z_1 :: U_1 and ... and z_n :: U_m
  5505     where
  5506       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  5507     | ...
  5508 
  5509   with full support for type-inference, rather than
  5510 
  5511     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5512 
  5513     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5514     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  5515 
  5516     inductive "s z_1 ... z_m"
  5517     intros
  5518       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  5519       ...
  5520 
  5521   For backward compatibility, there is a wrapper allowing inductive
  5522   sets to be defined with the new package via
  5523 
  5524     inductive_set
  5525       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5526       for z_1 :: U_1 and ... and z_n :: U_m
  5527     where
  5528       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  5529     | ...
  5530 
  5531   or
  5532 
  5533     inductive_set
  5534       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5535       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5536       for z_1 :: U_1 and ... and z_n :: U_m
  5537     where
  5538       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  5539     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  5540     | ...
  5541 
  5542   if the additional syntax "p ..." is required.
  5543 
  5544   Numerous examples can be found in the subdirectories src/HOL/Auth,
  5545   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  5546 
  5547   INCOMPATIBILITIES:
  5548 
  5549   - Since declaration and definition of inductive sets or predicates
  5550     is no longer separated, abbreviations involving the newly
  5551     introduced sets or predicates must be specified together with the
  5552     introduction rules after the 'where' keyword (see above), rather
  5553     than before the actual inductive definition.
  5554 
  5555   - The variables in induction and elimination rules are now
  5556     quantified in the order of their occurrence in the introduction
  5557     rules, rather than in alphabetical order. Since this may break
  5558     some proofs, these proofs either have to be repaired, e.g. by
  5559     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  5560     statements of the form
  5561 
  5562       case (rule_i a_i_1 ... a_i_{k_i})
  5563 
  5564     or the old order of quantification has to be restored by explicitly adding
  5565     meta-level quantifiers in the introduction rules, i.e.
  5566 
  5567       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  5568 
  5569   - The format of the elimination rules is now
  5570 
  5571       p z_1 ... z_m x_1 ... x_n ==>
  5572         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5573         ==> ... ==> P
  5574 
  5575     for predicates and
  5576 
  5577       (x_1, ..., x_n) : s z_1 ... z_m ==>
  5578         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5579         ==> ... ==> P
  5580 
  5581     for sets rather than
  5582 
  5583       x : s z_1 ... z_m ==>
  5584         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  5585         ==> ... ==> P
  5586 
  5587     This may require terms in goals to be expanded to n-tuples
  5588     (e.g. using case_tac or simplification with the split_paired_all
  5589     rule) before the above elimination rule is applicable.
  5590 
  5591   - The elimination or case analysis rules for (mutually) inductive
  5592     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  5593     list of rules "p_1_..._p_k.elims" is no longer available.
  5594 
  5595 * New package "function"/"fun" for general recursive functions,
  5596 supporting mutual and nested recursion, definitions in local contexts,
  5597 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  5598 for small examples, and the separate tutorial on the function
  5599 package. The old recdef "package" is still available as before, but
  5600 users are encouraged to use the new package.
  5601 
  5602 * Method "lexicographic_order" automatically synthesizes termination
  5603 relations as lexicographic combinations of size measures. 
  5604 
  5605 * Case-expressions allow arbitrary constructor-patterns (including
  5606 "_") and take their order into account, like in functional
  5607 programming.  Internally, this is translated into nested
  5608 case-expressions; missing cases are added and mapped to the predefined
  5609 constant "undefined". In complicated cases printing may no longer show
  5610 the original input but the internal form. Lambda-abstractions allow
  5611 the same form of pattern matching: "% pat1 => e1 | ..." is an
  5612 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  5613 variable.
  5614 
  5615 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  5616 is an abbreviation for "of_nat :: nat => int". The simplification
  5617 rules for "of_nat" have been changed to work like "int" did
  5618 previously.  Potential INCOMPATIBILITY:
  5619   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  5620   - of_nat_diff and of_nat_mult are no longer default simp rules
  5621 
  5622 * Method "algebra" solves polynomial equations over (semi)rings using
  5623 Groebner bases. The (semi)ring structure is defined by locales and the
  5624 tool setup depends on that generic context. Installing the method for
  5625 a specific type involves instantiating the locale and possibly adding
  5626 declarations for computation on the coefficients.  The method is
  5627 already instantiated for natural numbers and for the axiomatic class
  5628 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  5629 CALCULEMUS 2007 for the general principles underlying this
  5630 architecture of context-aware proof-tools.
  5631 
  5632 * Method "ferrack" implements quantifier elimination over
  5633 special-purpose dense linear orders using locales (analogous to
  5634 "algebra"). The method is already installed for class
  5635 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  5636 rat, etc.
  5637 
  5638 * Former constant "List.op @" now named "List.append".  Use ML
  5639 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  5640 circumvent possible incompatibilities when working on ML level.
  5641 
  5642 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  5643 
  5644 * New function listsum :: 'a list => 'a for arbitrary monoids.
  5645 Special syntax: "SUM x <- xs. f x" (and latex variants)
  5646 
  5647 * New syntax for Haskell-like list comprehension (input only), eg.
  5648 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  5649 
  5650 * The special syntax for function "filter" has changed from [x :
  5651 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  5652 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  5653 
  5654 * [a..b] is now defined for arbitrary linear orders.  It used to be
  5655 defined on nat only, as an abbreviation for [a..<Suc b]
  5656 INCOMPATIBILITY.
  5657 
  5658 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  5659 
  5660 * New functions "sorted" and "sort" in src/HOL/List.thy.
  5661 
  5662 * New lemma collection field_simps (an extension of ring_simps) for
  5663 manipulating (in)equations involving division. Multiplies with all
  5664 denominators that can be proved to be non-zero (in equations) or
  5665 positive/negative (in inequations).
  5666 
  5667 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  5668 have been improved and renamed to ring_simps, group_simps and
  5669 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  5670 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  5671 
  5672 * Theory Library/Commutative_Ring: switched from recdef to function
  5673 package; constants add, mul, pow now curried.  Infix syntax for
  5674 algebraic operations.
  5675 
  5676 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  5677 INCOMPATIBILITY.
  5678 
  5679 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  5680 INCOMPATIBILITY.
  5681 
  5682 * HOL/records: generalised field-update to take a function on the
  5683 field rather than the new value: r(|A := x|) is translated to A_update
  5684 (K x) r The K-combinator that is internally used is called K_record.
  5685 INCOMPATIBILITY: Usage of the plain update functions has to be
  5686 adapted.
  5687  
  5688 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  5689 * x = 0, which are required for a semiring.  Richer structures do not
  5690 inherit from semiring_0 anymore, because this property is a theorem
  5691 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  5692 there is more to prove, but this is mostly trivial.
  5693 
  5694 * Class "recpower" is generalized to arbitrary monoids, not just
  5695 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  5696 commutativity or semiring properties additionally.
  5697 
  5698 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  5699 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  5700 better use 'abbreviation'.
  5701 
  5702 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  5703 
  5704 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  5705 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  5706 significant changes for setting up numeral syntax for types:
  5707   - New constants Numeral.pred and Numeral.succ instead
  5708       of former Numeral.bin_pred and Numeral.bin_succ.
  5709   - Use integer operations instead of bin_add, bin_mult and so on.
  5710   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  5711   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  5712 
  5713 See src/HOL/Integ/IntArith.thy for an example setup.
  5714 
  5715 * Command 'normal_form' computes the normal form of a term that may
  5716 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  5717 produces ``[b, c, a]'' (without proof).  This command is suitable for
  5718 heavy-duty computations because the functions are compiled to ML
  5719 first.  Correspondingly, a method "normalization" is provided.  See
  5720 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  5721 
  5722 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  5723 25 like -->); output depends on the "iff" print_mode, the default is
  5724 "A = B" (with priority 50).
  5725 
  5726 * Relations less (<) and less_eq (<=) are also available on type bool.
  5727 Modified syntax to disallow nesting without explicit parentheses,
  5728 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  5729 INCOMPATIBILITY.
  5730 
  5731 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  5732 
  5733 * Relation composition operator "op O" now has precedence 75 and binds
  5734 stronger than union and intersection. INCOMPATIBILITY.
  5735 
  5736 * The old set interval syntax "{m..n(}" (and relatives) has been
  5737 removed.  Use "{m..<n}" (and relatives) instead.
  5738 
  5739 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  5740 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  5741 ``declare [[simproc del: neq]]''.
  5742 
  5743 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  5744 True/False.
  5745 
  5746 * Theorem Cons_eq_map_conv no longer declared as "simp".
  5747 
  5748 * Theorem setsum_mult renamed to setsum_right_distrib.
  5749 
  5750 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  5751 ``rule'' method.
  5752 
  5753 * Reimplemented methods "sat" and "satx", with several improvements:
  5754 goals no longer need to be stated as "<prems> ==> False", equivalences
  5755 (i.e. "=" on type bool) are handled, variable names of the form
  5756 "lit_<n>" are no longer reserved, significant speedup.
  5757 
  5758 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  5759 zChaff is still supported as well.
  5760 
  5761 * 'inductive' and 'datatype': provide projections of mutual rules,
  5762 bundled as foo_bar.inducts;
  5763 
  5764 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  5765 Library.
  5766 
  5767 * Library: moved theory Accessible_Part to main HOL.
  5768 
  5769 * Library: added theory Coinductive_List of potentially infinite lists
  5770 as greatest fixed-point.
  5771 
  5772 * Library: added theory AssocList which implements (finite) maps as
  5773 association lists.
  5774 
  5775 * Method "evaluation" solves goals (i.e. a boolean expression)
  5776 efficiently by compiling it to ML.  The goal is "proved" (via an
  5777 oracle) if it evaluates to True.
  5778 
  5779 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  5780 also when invoked by the simplifier.  This results in the Simplifier
  5781 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  5782 Configuration option fast_arith_split_limit=0 recovers the old
  5783 behavior.
  5784 
  5785 * Support for hex (0x20) and binary (0b1001) numerals.
  5786 
  5787 * New method: reify eqs (t), where eqs are equations for an
  5788 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  5789 parameter, computes a term s::'b and a list xs::'a list and proves the
  5790 theorem I xs s = t. This is also known as reification or quoting. The
  5791 resulting theorem is applied to the subgoal to substitute t with I xs
  5792 s.  If t is omitted, the subgoal itself is reified.
  5793 
  5794 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  5795 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  5796 where f is supposed to be a computable function (in the sense of code
  5797 generattion). The method uses reify to compute s and xs as above then
  5798 applies corr_thm and uses normalization by evaluation to "prove" f s =
  5799 r and finally gets the theorem t = r, which is again applied to the
  5800 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  5801 
  5802 * Reflection: Automatic reification now handels binding, an example is
  5803 available in src/HOL/ex/ReflectionEx.thy
  5804 
  5805 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  5806 command 'statespace' that is similar to 'record', but introduces an
  5807 abstract specification based on the locale infrastructure instead of
  5808 HOL types.  This leads to extra flexibility in composing state spaces,
  5809 in particular multiple inheritance and renaming of components.
  5810 
  5811 
  5812 *** HOL-Complex ***
  5813 
  5814 * Hyperreal: Functions root and sqrt are now defined on negative real
  5815 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  5816 Nonnegativity side conditions have been removed from many lemmas, so
  5817 that more subgoals may now be solved by simplification; potential
  5818 INCOMPATIBILITY.
  5819 
  5820 * Real: new type classes formalize real normed vector spaces and
  5821 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  5822 and norm :: 'a => real.
  5823 
  5824 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  5825 reals into other types. The overloaded constant Reals :: 'a set is now
  5826 defined as range of_real; potential INCOMPATIBILITY.
  5827 
  5828 * Real: proper support for ML code generation, including 'quickcheck'.
  5829 Reals are implemented as arbitrary precision rationals.
  5830 
  5831 * Hyperreal: Several constants that previously worked only for the
  5832 reals have been generalized, so they now work over arbitrary vector
  5833 spaces. Type annotations may need to be added in some cases; potential
  5834 INCOMPATIBILITY.
  5835 
  5836   Infinitesimal  :: ('a::real_normed_vector) star set
  5837   HFinite        :: ('a::real_normed_vector) star set
  5838   HInfinite      :: ('a::real_normed_vector) star set
  5839   approx         :: ('a::real_normed_vector) star => 'a star => bool
  5840   monad          :: ('a::real_normed_vector) star => 'a star set
  5841   galaxy         :: ('a::real_normed_vector) star => 'a star set
  5842   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  5843   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  5844   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  5845   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  5846   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  5847   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  5848   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5849   sgn            :: 'a::real_normed_vector => 'a
  5850   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5851 
  5852 * Complex: Some complex-specific constants are now abbreviations for
  5853 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5854 hnorm.  Other constants have been entirely removed in favor of the
  5855 polymorphic versions (INCOMPATIBILITY):
  5856 
  5857   approx        <-- capprox
  5858   HFinite       <-- CFinite
  5859   HInfinite     <-- CInfinite
  5860   Infinitesimal <-- CInfinitesimal
  5861   monad         <-- cmonad
  5862   galaxy        <-- cgalaxy
  5863   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5864   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5865   (ns)deriv     <-- (ns)cderiv
  5866 
  5867 
  5868 *** HOL-Algebra ***
  5869 
  5870 * Formalisation of ideals and the quotient construction over rings.
  5871 
  5872 * Order and lattice theory no longer based on records.
  5873 INCOMPATIBILITY.
  5874 
  5875 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5876 greatest_closed.  INCOMPATIBILITY.
  5877 
  5878 * Method algebra is now set up via an attribute.  For examples see
  5879 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5880 of algebraic structures.
  5881 
  5882 * Renamed theory CRing to Ring.
  5883 
  5884 
  5885 *** HOL-Nominal ***
  5886 
  5887 * Substantial, yet incomplete support for nominal datatypes (binding
  5888 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5889 src/HOL/Nominal/Examples.  Prospective users should consult
  5890 http://isabelle.in.tum.de/nominal/
  5891 
  5892 
  5893 *** ML ***
  5894 
  5895 * ML basics: just one true type int, which coincides with IntInf.int
  5896 (even on SML/NJ).
  5897 
  5898 * ML within Isar: antiquotations allow to embed statically-checked
  5899 formal entities in the source, referring to the context available at
  5900 compile-time.  For example:
  5901 
  5902 ML {* @{sort "{zero,one}"} *}
  5903 ML {* @{typ "'a => 'b"} *}
  5904 ML {* @{term "%x. x"} *}
  5905 ML {* @{prop "x == y"} *}
  5906 ML {* @{ctyp "'a => 'b"} *}
  5907 ML {* @{cterm "%x. x"} *}
  5908 ML {* @{cprop "x == y"} *}
  5909 ML {* @{thm asm_rl} *}
  5910 ML {* @{thms asm_rl} *}
  5911 ML {* @{type_name c} *}
  5912 ML {* @{type_syntax c} *}
  5913 ML {* @{const_name c} *}
  5914 ML {* @{const_syntax c} *}
  5915 ML {* @{context} *}
  5916 ML {* @{theory} *}
  5917 ML {* @{theory Pure} *}
  5918 ML {* @{theory_ref} *}
  5919 ML {* @{theory_ref Pure} *}
  5920 ML {* @{simpset} *}
  5921 ML {* @{claset} *}
  5922 ML {* @{clasimpset} *}
  5923 
  5924 The same works for sources being ``used'' within an Isar context.
  5925 
  5926 * ML in Isar: improved error reporting; extra verbosity with
  5927 ML_Context.trace enabled.
  5928 
  5929 * Pure/General/table.ML: the join operations now works via exceptions
  5930 DUP/SAME instead of type option. This is simpler in simple cases, and
  5931 admits slightly more efficient complex applications.
  5932 
  5933 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5934 use Context.generic instead of just theory.
  5935 
  5936 * Pure: datatype Context.generic joins theory/Proof.context and
  5937 provides some facilities for code that works in either kind of
  5938 context, notably GenericDataFun for uniform theory and proof data.
  5939 
  5940 * Pure: simplified internal attribute type, which is now always
  5941 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5942 local (Proof.context) attributes have been discontinued, while
  5943 minimizing code duplication. Thm.rule_attribute and
  5944 Thm.declaration_attribute build canonical attributes; see also structure
  5945 Context for further operations on Context.generic, notably
  5946 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5947 declarations and definitions.
  5948 
  5949 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5950 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5951 init only required for impure data. INCOMPATIBILITY: empty really need
  5952 to be empty (no dependencies on theory content!)
  5953 
  5954 * Pure/kernel: consts certification ignores sort constraints given in
  5955 signature declarations. (This information is not relevant to the
  5956 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5957 potential INCOMPATIBILITY.
  5958 
  5959 * Pure: axiomatic type classes are now purely definitional, with
  5960 explicit proofs of class axioms and super class relations performed
  5961 internally. See Pure/axclass.ML for the main internal interfaces --
  5962 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5963 AxClass.axiomatize_class/classrel/arity supersede
  5964 Sign.add_classes/classrel/arities.
  5965 
  5966 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5967 global/local versions on theory vs. Proof.context have been
  5968 discontinued; Attrib.syntax and Method.syntax have been adapted
  5969 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5970 attributes, methods, etc.
  5971 
  5972 * Pure: several functions of signature "... -> theory -> theory * ..."
  5973 have been reoriented to "... -> theory -> ... * theory" in order to
  5974 allow natural usage in combination with the ||>, ||>>, |-> and
  5975 fold_map combinators.
  5976 
  5977 * Pure: official theorem names (closed derivations) and additional
  5978 comments (tags) are now strictly separate.  Name hints -- which are
  5979 maintained as tags -- may be attached any time without affecting the
  5980 derivation.
  5981 
  5982 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5983 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5984 achieve the old behaviour.
  5985 
  5986 * Pure: the "Goal" constant is now called "prop", supporting a
  5987 slightly more general idea of ``protecting'' meta-level rule
  5988 statements.
  5989 
  5990 * Pure: Logic.(un)varify only works in a global context, which is now
  5991 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5992 Logic.legacy_(un)varify as temporary workaround.
  5993 
  5994 * Pure: structure Name provides scalable operations for generating
  5995 internal variable names, notably Name.variants etc.  This replaces
  5996 some popular functions from term.ML:
  5997 
  5998   Term.variant		->  Name.variant
  5999   Term.variantlist	->  Name.variant_list
  6000   Term.invent_names	->  Name.invent_list
  6001 
  6002 Note that low-level renaming rarely occurs in new code -- operations
  6003 from structure Variable are used instead (see below).
  6004 
  6005 * Pure: structure Variable provides fundamental operations for proper
  6006 treatment of fixed/schematic variables in a context.  For example,
  6007 Variable.import introduces fixes for schematics of given facts and
  6008 Variable.export reverses the effect (up to renaming) -- this replaces
  6009 various freeze_thaw operations.
  6010 
  6011 * Pure: structure Goal provides simple interfaces for
  6012 init/conclude/finish and tactical prove operations (replacing former
  6013 Tactic.prove).  Goal.prove is the canonical way to prove results
  6014 within a given context; Goal.prove_global is a degraded version for
  6015 theory level goals, including a global Drule.standard.  Note that
  6016 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  6017 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  6018 in a locale context).
  6019 
  6020 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  6021 and type checking (Syntax.check_term etc.), with common combinations
  6022 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  6023 which are considered legacy and await removal.
  6024 
  6025 * Pure/Syntax: generic interfaces for type unchecking
  6026 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  6027 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  6028 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  6029 available for convenience, but refer to the very same operations using
  6030 a mere theory instead of a full context.
  6031 
  6032 * Isar: simplified treatment of user-level errors, using exception
  6033 ERROR of string uniformly.  Function error now merely raises ERROR,
  6034 without any side effect on output channels.  The Isar toplevel takes
  6035 care of proper display of ERROR exceptions.  ML code may use plain
  6036 handle/can/try; cat_error may be used to concatenate errors like this:
  6037 
  6038   ... handle ERROR msg => cat_error msg "..."
  6039 
  6040 Toplevel ML code (run directly or through the Isar toplevel) may be
  6041 embedded into the Isar toplevel with exception display/debug like
  6042 this:
  6043 
  6044   Isar.toplevel (fn () => ...)
  6045 
  6046 INCOMPATIBILITY, removed special transform_error facilities, removed
  6047 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  6048 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  6049 -- use plain ERROR instead.
  6050 
  6051 * Isar: theory setup now has type (theory -> theory), instead of a
  6052 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  6053 
  6054 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  6055 ProofContext.debug/verbose flags.
  6056 
  6057 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  6058 theory before entering a proof state.  Transactions now always see a
  6059 quasi-functional intermediate checkpoint, both in interactive and
  6060 batch mode.
  6061 
  6062 * Isar: simplified interfaces for outer syntax.  Renamed
  6063 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  6064 OuterSyntax.add_parsers -- this functionality is now included in
  6065 OuterSyntax.command etc.  INCOMPATIBILITY.
  6066 
  6067 * Simplifier: the simpset of a running simplification process now
  6068 contains a proof context (cf. Simplifier.the_context), which is the
  6069 very context that the initial simpset has been retrieved from (by
  6070 simpset_of/local_simpset_of).  Consequently, all plug-in components
  6071 (solver, looper etc.) may depend on arbitrary proof data.
  6072 
  6073 * Simplifier.inherit_context inherits the proof context (plus the
  6074 local bounds) of the current simplification process; any simproc
  6075 etc. that calls the Simplifier recursively should do this!  Removed
  6076 former Simplifier.inherit_bounds, which is already included here --
  6077 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  6078 specify an explicit context using Simplifier.context/theory_context.
  6079 
  6080 * Simplifier/Classical Reasoner: more abstract interfaces
  6081 change_simpset/claset for modifying the simpset/claset reference of a
  6082 theory; raw versions simpset/claset_ref etc. have been discontinued --
  6083 INCOMPATIBILITY.
  6084 
  6085 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  6086 "Trueprop" etc.
  6087 
  6088 
  6089 *** System ***
  6090 
  6091 * settings: the default heap location within ISABELLE_HOME_USER now
  6092 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  6093 Isabelle installations.
  6094 
  6095 * isabelle-process: option -S (secure mode) disables some critical
  6096 operations, notably runtime compilation and evaluation of ML source
  6097 code.
  6098 
  6099 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  6100 
  6101 * Support for parallel execution, using native multicore support of
  6102 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  6103 independent theories, according to the given theory header
  6104 specifications. The maximum number of worker threads is specified via
  6105 usedir option -M or the "max-threads" setting in Proof General. A
  6106 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  6107 to 6 on a 8-core machine.  User-code needs to observe certain
  6108 guidelines for thread-safe programming, see appendix A in the Isar
  6109 Implementation manual.
  6110 
  6111 
  6112 
  6113 New in Isabelle2005 (October 2005)
  6114 ----------------------------------
  6115 
  6116 *** General ***
  6117 
  6118 * Theory headers: the new header syntax for Isar theories is
  6119 
  6120   theory <name>
  6121   imports <theory1> ... <theoryN>
  6122   uses <file1> ... <fileM>
  6123   begin
  6124 
  6125 where the 'uses' part is optional.  The previous syntax
  6126 
  6127   theory <name> = <theory1> + ... + <theoryN>:
  6128 
  6129 will disappear in the next release.  Use isatool fixheaders to convert
  6130 existing theory files.  Note that there is no change in ancient
  6131 non-Isar theories now, but these will disappear soon.
  6132 
  6133 * Theory loader: parent theories can now also be referred to via
  6134 relative and absolute paths.
  6135 
  6136 * Command 'find_theorems' searches for a list of criteria instead of a
  6137 list of constants. Known criteria are: intro, elim, dest, name:string,
  6138 simp:term, and any term. Criteria can be preceded by '-' to select
  6139 theorems that do not match. Intro, elim, dest select theorems that
  6140 match the current goal, name:s selects theorems whose fully qualified
  6141 name contain s, and simp:term selects all simplification rules whose
  6142 lhs match term.  Any other term is interpreted as pattern and selects
  6143 all theorems matching the pattern. Available in ProofGeneral under
  6144 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  6145 
  6146   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  6147 
  6148 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  6149 matching the current goal as introduction rule and not having "HOL."
  6150 in their name (i.e. not being defined in theory HOL).
  6151 
  6152 * Command 'thms_containing' has been discontinued in favour of
  6153 'find_theorems'; INCOMPATIBILITY.
  6154 
  6155 * Communication with Proof General is now 8bit clean, which means that
  6156 Unicode text in UTF-8 encoding may be used within theory texts (both
  6157 formal and informal parts).  Cf. option -U of the Isabelle Proof
  6158 General interface.  Here are some simple examples (cf. src/HOL/ex):
  6159 
  6160   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  6161   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  6162 
  6163 * Improved efficiency of the Simplifier and, to a lesser degree, the
  6164 Classical Reasoner.  Typical big applications run around 2 times
  6165 faster.
  6166 
  6167 
  6168 *** Document preparation ***
  6169 
  6170 * Commands 'display_drafts' and 'print_drafts' perform simple output
  6171 of raw sources.  Only those symbols that do not require additional
  6172 LaTeX packages (depending on comments in isabellesym.sty) are
  6173 displayed properly, everything else is left verbatim.  isatool display
  6174 and isatool print are used as front ends (these are subject to the
  6175 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  6176 
  6177 * Command tags control specific markup of certain regions of text,
  6178 notably folding and hiding.  Predefined tags include "theory" (for
  6179 theory begin and end), "proof" for proof commands, and "ML" for
  6180 commands involving ML code; the additional tags "visible" and
  6181 "invisible" are unused by default.  Users may give explicit tag
  6182 specifications in the text, e.g. ''by %invisible (auto)''.  The
  6183 interpretation of tags is determined by the LaTeX job during document
  6184 preparation: see option -V of isatool usedir, or options -n and -t of
  6185 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  6186 \isadroptag.
  6187 
  6188 Several document versions may be produced at the same time via isatool
  6189 usedir (the generated index.html will link all of them).  Typical
  6190 specifications include ''-V document=theory,proof,ML'' to present
  6191 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  6192 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  6193 these parts without any formal replacement text.  The Isabelle site
  6194 default settings produce ''document'' and ''outline'' versions as
  6195 specified above.
  6196 
  6197 * Several new antiquotations:
  6198 
  6199   @{term_type term} prints a term with its type annotated;
  6200 
  6201   @{typeof term} prints the type of a term;
  6202 
  6203   @{const const} is the same as @{term const}, but checks that the
  6204   argument is a known logical constant;
  6205 
  6206   @{term_style style term} and @{thm_style style thm} print a term or
  6207   theorem applying a "style" to it
  6208 
  6209   @{ML text}
  6210 
  6211 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  6212 definitions, equations, inequations etc., 'concl' printing only the
  6213 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  6214 to print the specified premise.  TermStyle.add_style provides an ML
  6215 interface for introducing further styles.  See also the "LaTeX Sugar"
  6216 document practical applications.  The ML antiquotation prints
  6217 type-checked ML expressions verbatim.
  6218 
  6219 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  6220 and 'text' support optional locale specification '(in loc)', which
  6221 specifies the default context for interpreting antiquotations.  For
  6222 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  6223 
  6224 * Option 'locale=NAME' of antiquotations specifies an alternative
  6225 context interpreting the subsequent argument.  For example: @{thm
  6226 [locale=lattice] inf_assoc}.
  6227 
  6228 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  6229 a proof context.
  6230 
  6231 * Proper output of antiquotations for theory commands involving a
  6232 proof context (such as 'locale' or 'theorem (in loc) ...').
  6233 
  6234 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  6235 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  6236 
  6237 * isatool usedir: new option -C (default true) controls whether option
  6238 -D should include a copy of the original document directory; -C false
  6239 prevents unwanted effects such as copying of administrative CVS data.
  6240 
  6241 
  6242 *** Pure ***
  6243 
  6244 * Considerably improved version of 'constdefs' command.  Now performs
  6245 automatic type-inference of declared constants; additional support for
  6246 local structure declarations (cf. locales and HOL records), see also
  6247 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  6248 sequential dependencies of definitions within a single 'constdefs'
  6249 section; moreover, the declared name needs to be an identifier.  If
  6250 all fails, consider to fall back on 'consts' and 'defs' separately.
  6251 
  6252 * Improved indexed syntax and implicit structures.  First of all,
  6253 indexed syntax provides a notational device for subscripted
  6254 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  6255 expressions.  Secondly, in a local context with structure
  6256 declarations, number indexes \<^sub>n or the empty index (default
  6257 number 1) refer to a certain fixed variable implicitly; option
  6258 show_structs controls printing of implicit structures.  Typical
  6259 applications of these concepts involve record types and locales.
  6260 
  6261 * New command 'no_syntax' removes grammar declarations (and
  6262 translations) resulting from the given syntax specification, which is
  6263 interpreted in the same manner as for the 'syntax' command.
  6264 
  6265 * 'Advanced' translation functions (parse_translation etc.) may depend
  6266 on the signature of the theory context being presently used for
  6267 parsing/printing, see also isar-ref manual.
  6268 
  6269 * Improved 'oracle' command provides a type-safe interface to turn an
  6270 ML expression of type theory -> T -> term into a primitive rule of
  6271 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  6272 is already included here); see also FOL/ex/IffExample.thy;
  6273 INCOMPATIBILITY.
  6274 
  6275 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  6276 before); "cI" is no longer bound, use "c.intro" instead.
  6277 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  6278 axclasses vs. locales.
  6279 
  6280 * Improved internal renaming of symbolic identifiers -- attach primes
  6281 instead of base 26 numbers.
  6282 
  6283 * New flag show_question_marks controls printing of leading question
  6284 marks in schematic variable names.
  6285 
  6286 * In schematic variable names, *any* symbol following \<^isub> or
  6287 \<^isup> is now treated as part of the base name.  For example, the
  6288 following works without printing of awkward ".0" indexes:
  6289 
  6290   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  6291     by simp
  6292 
  6293 * Inner syntax includes (*(*nested*) comments*).
  6294 
  6295 * Pretty printer now supports unbreakable blocks, specified in mixfix
  6296 annotations as "(00...)".
  6297 
  6298 * Clear separation of logical types and nonterminals, where the latter
  6299 may only occur in 'syntax' specifications or type abbreviations.
  6300 Before that distinction was only partially implemented via type class
  6301 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  6302 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  6303 exotic syntax specifications may require further adaption
  6304 (e.g. Cube/Cube.thy).
  6305 
  6306 * Removed obsolete type class "logic", use the top sort {} instead.
  6307 Note that non-logical types should be declared as 'nonterminals'
  6308 rather than 'types'.  INCOMPATIBILITY for new object-logic
  6309 specifications.
  6310 
  6311 * Attributes 'induct' and 'cases': type or set names may now be
  6312 locally fixed variables as well.
  6313 
  6314 * Simplifier: can now control the depth to which conditional rewriting
  6315 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  6316 Limit.
  6317 
  6318 * Simplifier: simplification procedures may now take the current
  6319 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  6320 interface), which is very useful for calling the Simplifier
  6321 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  6322 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  6323 low-level mk_simproc no longer applies Logic.varify internally, to
  6324 allow for use in a context of fixed variables.
  6325 
  6326 * thin_tac now works even if the assumption being deleted contains !!
  6327 or ==>.  More generally, erule now works even if the major premise of
  6328 the elimination rule contains !! or ==>.
  6329 
  6330 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  6331 
  6332 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  6333 from Pure, which contains all common declarations already.  Both
  6334 theories are defined via plain Isabelle/Isar .thy files.
  6335 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  6336 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  6337 use isatool fixcpure to adapt your theory and ML sources.
  6338 
  6339 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  6340 selections of theorems in named facts via index ranges.
  6341 
  6342 * 'print_theorems': in theory mode, really print the difference
  6343 wrt. the last state (works for interactive theory development only),
  6344 in proof mode print all local facts (cf. 'print_facts');
  6345 
  6346 * 'hide': option '(open)' hides only base names.
  6347 
  6348 * More efficient treatment of intermediate checkpoints in interactive
  6349 theory development.
  6350 
  6351 * Code generator is now invoked via code_module (incremental code
  6352 generation) and code_library (modular code generation, ML structures
  6353 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  6354 must be quoted when used as identifiers.
  6355 
  6356 * New 'value' command for reading, evaluating and printing terms using
  6357 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  6358 quoted when used as identifier.
  6359 
  6360 
  6361 *** Locales ***
  6362 
  6363 * New commands for the interpretation of locale expressions in
  6364 theories (1), locales (2) and proof contexts (3).  These generate
  6365 proof obligations from the expression specification.  After the
  6366 obligations have been discharged, theorems of the expression are added
  6367 to the theory, target locale or proof context.  The synopsis of the
  6368 commands is a follows:
  6369 
  6370   (1) interpretation expr inst
  6371   (2) interpretation target < expr
  6372   (3) interpret expr inst
  6373 
  6374 Interpretation in theories and proof contexts require a parameter
  6375 instantiation of terms from the current context.  This is applied to
  6376 specifications and theorems of the interpreted expression.
  6377 Interpretation in locales only permits parameter renaming through the
  6378 locale expression.  Interpretation is smart in that interpretations
  6379 that are active already do not occur in proof obligations, neither are
  6380 instantiated theorems stored in duplicate.  Use 'print_interps' to
  6381 inspect active interpretations of a particular locale.  For details,
  6382 see the Isar Reference manual.  Examples can be found in
  6383 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  6384 
  6385 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  6386 'interpret' instead.
  6387 
  6388 * New context element 'constrains' for adding type constraints to
  6389 parameters.
  6390 
  6391 * Context expressions: renaming of parameters with syntax
  6392 redeclaration.
  6393 
  6394 * Locale declaration: 'includes' disallowed.
  6395 
  6396 * Proper static binding of attribute syntax -- i.e. types / terms /
  6397 facts mentioned as arguments are always those of the locale definition
  6398 context, independently of the context of later invocations.  Moreover,
  6399 locale operations (renaming and type / term instantiation) are applied
  6400 to attribute arguments as expected.
  6401 
  6402 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  6403 actual attributes; rare situations may require Attrib.attribute to
  6404 embed those attributes into Attrib.src that lack concrete syntax.
  6405 Attribute implementations need to cooperate properly with the static
  6406 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  6407 Attrib.XXX_thm etc. already do the right thing without further
  6408 intervention.  Only unusual applications -- such as "where" or "of"
  6409 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  6410 on the context and the facts involved -- may have to assign parsed
  6411 values to argument tokens explicitly.
  6412 
  6413 * Changed parameter management in theorem generation for long goal
  6414 statements with 'includes'.  INCOMPATIBILITY: produces a different
  6415 theorem statement in rare situations.
  6416 
  6417 * Locale inspection command 'print_locale' omits notes elements.  Use
  6418 'print_locale!' to have them included in the output.
  6419 
  6420 
  6421 *** Provers ***
  6422 
  6423 * Provers/hypsubst.ML: improved version of the subst method, for
  6424 single-step rewriting: it now works in bound variable contexts. New is
  6425 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  6426 rewrite a different subterm than the original subst method, which is
  6427 still available as 'simplesubst'.
  6428 
  6429 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  6430 and quasi orders.
  6431 
  6432 * Provers/trancl.ML: new transitivity reasoner for transitive and
  6433 reflexive-transitive closure of relations.
  6434 
  6435 * Provers/blast.ML: new reference depth_limit to make blast's depth
  6436 limit (previously hard-coded with a value of 20) user-definable.
  6437 
  6438 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  6439 is peformed already.  Object-logics merely need to finish their
  6440 initial simpset configuration as before.  INCOMPATIBILITY.
  6441 
  6442 
  6443 *** HOL ***
  6444 
  6445 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  6446 
  6447   syntax (epsilon)
  6448     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  6449 
  6450 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  6451 and x-symbol; use option '-m epsilon' to get it actually printed.
  6452 Moreover, the mathematically important symbolic identifier \<epsilon>
  6453 becomes available as variable, constant etc.  INCOMPATIBILITY,
  6454 
  6455 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  6456 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  6457 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  6458 support corresponding Isar calculations.
  6459 
  6460 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  6461 instead of ":".
  6462 
  6463 * theory SetInterval: changed the syntax for open intervals:
  6464 
  6465   Old       New
  6466   {..n(}    {..<n}
  6467   {)n..}    {n<..}
  6468   {m..n(}   {m..<n}
  6469   {)m..n}   {m<..n}
  6470   {)m..n(}  {m<..<n}
  6471 
  6472 The old syntax is still supported but will disappear in the next
  6473 release.  For conversion use the following Emacs search and replace
  6474 patterns (these are not perfect but work quite well):
  6475 
  6476   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  6477   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  6478 
  6479 * Theory Commutative_Ring (in Library): method comm_ring for proving
  6480 equalities in commutative rings; method 'algebra' provides a generic
  6481 interface.
  6482 
  6483 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  6484 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  6485 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  6486 be a tuple pattern.
  6487 
  6488 Some new syntax forms are available:
  6489 
  6490   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  6491   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  6492   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  6493   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  6494 
  6495 The latter form "\<Sum>x < k. e" used to be based on a separate
  6496 function "Summation", which has been discontinued.
  6497 
  6498 * theory Finite_Set: in structured induction proofs, the insert case
  6499 is now 'case (insert x F)' instead of the old counterintuitive 'case
  6500 (insert F x)'.
  6501 
  6502 * The 'refute' command has been extended to support a much larger
  6503 fragment of HOL, including axiomatic type classes, constdefs and
  6504 typedefs, inductive datatypes and recursion.
  6505 
  6506 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  6507 Requires zChaff with proof generation to be installed.  See
  6508 HOL/ex/SAT_Examples.thy for examples.
  6509 
  6510 * Datatype induction via method 'induct' now preserves the name of the
  6511 induction variable. For example, when proving P(xs::'a list) by
  6512 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  6513 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  6514 in unstructured proof scripts.
  6515 
  6516 * Reworked implementation of records.  Improved scalability for
  6517 records with many fields, avoiding performance problems for type
  6518 inference. Records are no longer composed of nested field types, but
  6519 of nested extension types. Therefore the record type only grows linear
  6520 in the number of extensions and not in the number of fields.  The
  6521 top-level (users) view on records is preserved.  Potential
  6522 INCOMPATIBILITY only in strange cases, where the theory depends on the
  6523 old record representation. The type generated for a record is called
  6524 <record_name>_ext_type.
  6525 
  6526 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  6527 proofs triggered by a record definition or a simproc (if
  6528 quick_and_dirty is enabled).  Definitions of large records can take
  6529 quite long.
  6530 
  6531 New simproc record_upd_simproc for simplification of multiple record
  6532 updates enabled by default.  Moreover, trivial updates are also
  6533 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  6534 occasionally, since simplification is more powerful by default.
  6535 
  6536 * typedef: proper support for polymorphic sets, which contain extra
  6537 type-variables in the term.
  6538 
  6539 * Simplifier: automatically reasons about transitivity chains
  6540 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  6541 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  6542 old proofs break occasionally as simplification may now solve more
  6543 goals than previously.
  6544 
  6545 * Simplifier: converts x <= y into x = y if assumption y <= x is
  6546 present.  Works for all partial orders (class "order"), in particular
  6547 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  6548 just like y <= x.
  6549 
  6550 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  6551 bound variable or a constant then the let is unfolded.  Otherwise
  6552 first a is simplified to b, and then f b is simplified to g. If
  6553 possible we abstract b from g arriving at "let x = b in h x",
  6554 otherwise we unfold the let and arrive at g.  The simproc can be
  6555 enabled/disabled by the reference use_let_simproc.  Potential
  6556 INCOMPATIBILITY since simplification is more powerful by default.
  6557 
  6558 * Classical reasoning: the meson method now accepts theorems as arguments.
  6559 
  6560 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  6561 jobs to provide advice on the provability of subgoals.
  6562 
  6563 * Theory OrderedGroup and Ring_and_Field: various additions and
  6564 improvements to faciliate calculations involving equalities and
  6565 inequalities.
  6566 
  6567 The following theorems have been eliminated or modified
  6568 (INCOMPATIBILITY):
  6569 
  6570   abs_eq             now named abs_of_nonneg
  6571   abs_of_ge_0        now named abs_of_nonneg
  6572   abs_minus_eq       now named abs_of_nonpos
  6573   imp_abs_id         now named abs_of_nonneg
  6574   imp_abs_neg_id     now named abs_of_nonpos
  6575   mult_pos           now named mult_pos_pos
  6576   mult_pos_le        now named mult_nonneg_nonneg
  6577   mult_pos_neg_le    now named mult_nonneg_nonpos
  6578   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  6579   mult_neg           now named mult_neg_neg
  6580   mult_neg_le        now named mult_nonpos_nonpos
  6581 
  6582 * The following lemmas in Ring_and_Field have been added to the simplifier:
  6583      
  6584      zero_le_square
  6585      not_square_less_zero 
  6586 
  6587   The following lemmas have been deleted from Real/RealPow:
  6588   
  6589      realpow_zero_zero
  6590      realpow_two
  6591      realpow_less
  6592      zero_le_power
  6593      realpow_two_le
  6594      abs_realpow_two
  6595      realpow_two_abs     
  6596 
  6597 * Theory Parity: added rules for simplifying exponents.
  6598 
  6599 * Theory List:
  6600 
  6601 The following theorems have been eliminated or modified
  6602 (INCOMPATIBILITY):
  6603 
  6604   list_all_Nil       now named list_all.simps(1)
  6605   list_all_Cons      now named list_all.simps(2)
  6606   list_all_conv      now named list_all_iff
  6607   set_mem_eq         now named mem_iff
  6608 
  6609 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  6610 asymptotic "big O" calculations.  See the notes in BigO.thy.
  6611 
  6612 
  6613 *** HOL-Complex ***
  6614 
  6615 * Theory RealDef: better support for embedding natural numbers and
  6616 integers in the reals.
  6617 
  6618 The following theorems have been eliminated or modified
  6619 (INCOMPATIBILITY):
  6620 
  6621   exp_ge_add_one_self  now requires no hypotheses
  6622   real_of_int_add      reversed direction of equality (use [symmetric])
  6623   real_of_int_minus    reversed direction of equality (use [symmetric])
  6624   real_of_int_diff     reversed direction of equality (use [symmetric])
  6625   real_of_int_mult     reversed direction of equality (use [symmetric])
  6626 
  6627 * Theory RComplete: expanded support for floor and ceiling functions.
  6628 
  6629 * Theory Ln is new, with properties of the natural logarithm
  6630 
  6631 * Hyperreal: There is a new type constructor "star" for making
  6632 nonstandard types.  The old type names are now type synonyms:
  6633 
  6634   hypreal = real star
  6635   hypnat = nat star
  6636   hcomplex = complex star
  6637 
  6638 * Hyperreal: Many groups of similarly-defined constants have been
  6639 replaced by polymorphic versions (INCOMPATIBILITY):
  6640 
  6641   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  6642 
  6643   starset      <-- starsetNat, starsetC
  6644   *s*          <-- *sNat*, *sc*
  6645   starset_n    <-- starsetNat_n, starsetC_n
  6646   *sn*         <-- *sNatn*, *scn*
  6647   InternalSets <-- InternalNatSets, InternalCSets
  6648 
  6649   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  6650   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  6651   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  6652   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  6653   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  6654 
  6655 * Hyperreal: Many type-specific theorems have been removed in favor of
  6656 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  6657 
  6658   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  6659   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  6660   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  6661   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  6662   right_minus <-- hypreal_add_minus
  6663   left_minus <-- {hypreal,hcomplex}_add_minus_left
  6664   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  6665   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  6666   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  6667   mult_1_right <-- hcomplex_mult_one_right
  6668   mult_zero_left <-- hcomplex_mult_zero_left
  6669   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  6670   right_distrib <-- hypnat_add_mult_distrib2
  6671   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  6672   right_inverse <-- hypreal_mult_inverse
  6673   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  6674   order_refl <-- {hypreal,hypnat}_le_refl
  6675   order_trans <-- {hypreal,hypnat}_le_trans
  6676   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  6677   order_less_le <-- {hypreal,hypnat}_less_le
  6678   linorder_linear <-- {hypreal,hypnat}_le_linear
  6679   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  6680   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  6681   add_nonneg_nonneg <-- hypreal_le_add_order
  6682 
  6683 * Hyperreal: Separate theorems having to do with type-specific
  6684 versions of constants have been merged into theorems that apply to the
  6685 new polymorphic constants (INCOMPATIBILITY):
  6686 
  6687   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  6688   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  6689   STAR_Un <-- {STAR,NatStar,STARC}_Un
  6690   STAR_Int <-- {STAR,NatStar,STARC}_Int
  6691   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  6692   STAR_subset <-- {STAR,NatStar,STARC}_subset
  6693   STAR_mem <-- {STAR,NatStar,STARC}_mem
  6694   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  6695   STAR_diff <-- {STAR,STARC}_diff
  6696   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  6697     STARC_hcomplex_of_complex}_image_subset
  6698   starset_n_Un <-- starset{Nat,C}_n_Un
  6699   starset_n_Int <-- starset{Nat,C}_n_Int
  6700   starset_n_Compl <-- starset{Nat,C}_n_Compl
  6701   starset_n_diff <-- starset{Nat,C}_n_diff
  6702   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  6703   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  6704   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  6705   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  6706   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  6707   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  6708   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  6709   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  6710   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  6711   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  6712   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  6713   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  6714   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  6715   starfun_diff <-- starfun{C,RC,CR}_diff
  6716   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  6717   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  6718   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  6719   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  6720   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  6721   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  6722   starfun_Id <-- starfunC_Id
  6723   starfun_approx <-- starfun{Nat,CR}_approx
  6724   starfun_capprox <-- starfun{C,RC}_capprox
  6725   starfun_abs <-- starfunNat_rabs
  6726   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  6727   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  6728   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  6729   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  6730   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  6731   starfun_add_approx <-- starfunCR_add_approx
  6732   starfun_inverse_inverse <-- starfunC_inverse_inverse
  6733   starfun_divide <-- starfun{C,CR,RC}_divide
  6734   starfun_n <-- starfun{Nat,C}_n
  6735   starfun_n_mult <-- starfun{Nat,C}_n_mult
  6736   starfun_n_add <-- starfun{Nat,C}_n_add
  6737   starfun_n_add_minus <-- starfunNat_n_add_minus
  6738   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  6739   starfun_n_minus <-- starfun{Nat,C}_n_minus
  6740   starfun_n_eq <-- starfun{Nat,C}_n_eq
  6741 
  6742   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  6743   star_n_minus <-- {hypreal,hcomplex}_minus
  6744   star_n_diff <-- {hypreal,hcomplex}_diff
  6745   star_n_mult <-- {hypreal,hcomplex}_mult
  6746   star_n_inverse <-- {hypreal,hcomplex}_inverse
  6747   star_n_le <-- {hypreal,hypnat}_le
  6748   star_n_less <-- {hypreal,hypnat}_less
  6749   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  6750   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  6751   star_n_abs <-- hypreal_hrabs
  6752   star_n_divide <-- hcomplex_divide
  6753 
  6754   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  6755   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  6756   star_of_diff <-- hypreal_of_real_diff
  6757   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  6758   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  6759   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  6760   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  6761   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  6762   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  6763   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  6764   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  6765   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  6766   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  6767   star_of_number_of <-- {hypreal,hcomplex}_number_of
  6768   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  6769   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  6770   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  6771   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  6772   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  6773   star_of_power <-- hypreal_of_real_power
  6774   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  6775 
  6776 * Hyperreal: new method "transfer" that implements the transfer
  6777 principle of nonstandard analysis. With a subgoal that mentions
  6778 nonstandard types like "'a star", the command "apply transfer"
  6779 replaces it with an equivalent one that mentions only standard types.
  6780 To be successful, all free variables must have standard types; non-
  6781 standard variables must have explicit universal quantifiers.
  6782 
  6783 * Hyperreal: A theory of Taylor series.
  6784 
  6785 
  6786 *** HOLCF ***
  6787 
  6788 * Discontinued special version of 'constdefs' (which used to support
  6789 continuous functions) in favor of the general Pure one with full
  6790 type-inference.
  6791 
  6792 * New simplification procedure for solving continuity conditions; it
  6793 is much faster on terms with many nested lambda abstractions (cubic
  6794 instead of exponential time).
  6795 
  6796 * New syntax for domain package: selector names are now optional.
  6797 Parentheses should be omitted unless argument is lazy, for example:
  6798 
  6799   domain 'a stream = cons "'a" (lazy "'a stream")
  6800 
  6801 * New command 'fixrec' for defining recursive functions with pattern
  6802 matching; defining multiple functions with mutual recursion is also
  6803 supported.  Patterns may include the constants cpair, spair, up, sinl,
  6804 sinr, or any data constructor defined by the domain package. The given
  6805 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  6806 syntax and examples.
  6807 
  6808 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  6809 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  6810 but the proof obligation additionally includes an admissibility
  6811 requirement. The packages generate instances of class cpo or pcpo,
  6812 with continuity and strictness theorems for Rep and Abs.
  6813 
  6814 * HOLCF: Many theorems have been renamed according to a more standard naming
  6815 scheme (INCOMPATIBILITY):
  6816 
  6817   foo_inject:  "foo$x = foo$y ==> x = y"
  6818   foo_eq:      "(foo$x = foo$y) = (x = y)"
  6819   foo_less:    "(foo$x << foo$y) = (x << y)"
  6820   foo_strict:  "foo$UU = UU"
  6821   foo_defined: "... ==> foo$x ~= UU"
  6822   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  6823 
  6824 
  6825 *** ZF ***
  6826 
  6827 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  6828 including the First Isomorphism Theorem (on quotienting by the kernel
  6829 of a homomorphism).
  6830 
  6831 * ZF/Simplifier: install second copy of type solver that actually
  6832 makes use of TC rules declared to Isar proof contexts (or locales);
  6833 the old version is still required for ML proof scripts.
  6834 
  6835 
  6836 *** Cube ***
  6837 
  6838 * Converted to Isar theory format; use locales instead of axiomatic
  6839 theories.
  6840 
  6841 
  6842 *** ML ***
  6843 
  6844 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  6845 for ||>, ||>>, |>>,
  6846 
  6847 * Pure/library.ML no longer defines its own option datatype, but uses
  6848 that of the SML basis, which has constructors NONE and SOME instead of
  6849 None and Some, as well as exception Option.Option instead of OPTION.
  6850 The functions the, if_none, is_some, is_none have been adapted
  6851 accordingly, while Option.map replaces apsome.
  6852 
  6853 * Pure/library.ML: the exception LIST has been given up in favour of
  6854 the standard exceptions Empty and Subscript, as well as
  6855 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6856 superceded by the standard hd and tl functions etc.
  6857 
  6858 A number of basic list functions are no longer exported to the ML
  6859 toplevel, as they are variants of predefined functions.  The following
  6860 suggests how one can translate existing code:
  6861 
  6862     rev_append xs ys = List.revAppend (xs, ys)
  6863     nth_elem (i, xs) = List.nth (xs, i)
  6864     last_elem xs = List.last xs
  6865     flat xss = List.concat xss
  6866     seq fs = List.app fs
  6867     partition P xs = List.partition P xs
  6868     mapfilter f xs = List.mapPartial f xs
  6869 
  6870 * Pure/library.ML: several combinators for linear functional
  6871 transformations, notably reverse application and composition:
  6872 
  6873   x |> f                f #> g
  6874   (x, y) |-> f          f #-> g
  6875 
  6876 * Pure/library.ML: introduced/changed precedence of infix operators:
  6877 
  6878   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6879   infix 2 ?;
  6880   infix 3 o oo ooo oooo;
  6881   infix 4 ~~ upto downto;
  6882 
  6883 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6884 infix operators.
  6885 
  6886 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6887 fold_map support linear functional transformations and nesting.  For
  6888 example:
  6889 
  6890   fold f [x1, ..., xN] y =
  6891     y |> f x1 |> ... |> f xN
  6892 
  6893   (fold o fold) f [xs1, ..., xsN] y =
  6894     y |> fold f xs1 |> ... |> fold f xsN
  6895 
  6896   fold f [x1, ..., xN] =
  6897     f x1 #> ... #> f xN
  6898 
  6899   (fold o fold) f [xs1, ..., xsN] =
  6900     fold f xs1 #> ... #> fold f xsN
  6901 
  6902 * Pure/library.ML: the following selectors on type 'a option are
  6903 available:
  6904 
  6905   the:               'a option -> 'a  (*partial*)
  6906   these:             'a option -> 'a  where 'a = 'b list
  6907   the_default: 'a -> 'a option -> 'a
  6908   the_list:          'a option -> 'a list
  6909 
  6910 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6911 basic operations for association lists, following natural argument
  6912 order; moreover the explicit equality predicate passed here avoids
  6913 potentially expensive polymorphic runtime equality checks.
  6914 The old functions may be expressed as follows:
  6915 
  6916   assoc = uncurry (AList.lookup (op =))
  6917   assocs = these oo AList.lookup (op =)
  6918   overwrite = uncurry (AList.update (op =)) o swap
  6919 
  6920 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6921 
  6922   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6923   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6924 
  6925 replacing make_keylist and keyfilter (occassionally used)
  6926 Naive rewrites:
  6927 
  6928   make_keylist = AList.make
  6929   keyfilter = AList.find (op =)
  6930 
  6931 * eq_fst and eq_snd now take explicit equality parameter, thus
  6932   avoiding eqtypes. Naive rewrites:
  6933 
  6934     eq_fst = eq_fst (op =)
  6935     eq_snd = eq_snd (op =)
  6936 
  6937 * Removed deprecated apl and apr (rarely used).
  6938   Naive rewrites:
  6939 
  6940     apl (n, op) =>>= curry op n
  6941     apr (op, m) =>>= fn n => op (n, m)
  6942 
  6943 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6944 provides a reasonably efficient light-weight implementation of sets as
  6945 lists.
  6946 
  6947 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6948 few new operations; existing lookup and update are now curried to
  6949 follow natural argument order (for use with fold etc.);
  6950 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6951 
  6952 * Pure/General: output via the Isabelle channels of
  6953 writeln/warning/error etc. is now passed through Output.output, with a
  6954 hook for arbitrary transformations depending on the print_mode
  6955 (cf. Output.add_mode -- the first active mode that provides a output
  6956 function wins).  Already formatted output may be embedded into further
  6957 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6958 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6959 accommodate easy composition of diagnostic messages etc.  Programmers
  6960 rarely need to care about Output.output or Output.raw at all, with
  6961 some notable exceptions: Output.output is required when bypassing the
  6962 standard channels (writeln etc.), or in token translations to produce
  6963 properly formatted results; Output.raw is required when capturing
  6964 already output material that will eventually be presented to the user
  6965 a second time.  For the default print mode, both Output.output and
  6966 Output.raw have no effect.
  6967 
  6968 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6969 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6970 cumulative results are displayed at the end of a batch session.
  6971 
  6972 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6973 replaced by File.platform_path and File.shell_path (with appropriate
  6974 hooks).  This provides a clean interface for unusual systems where the
  6975 internal and external process view of file names are different.
  6976 
  6977 * Pure: more efficient orders for basic syntactic entities: added
  6978 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6979 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6980 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6981 orders now -- potential INCOMPATIBILITY for code that depends on a
  6982 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6983 Library.sort_strings on result).
  6984 
  6985 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6986 fold_types traverse types/terms from left to right, observing natural
  6987 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6988 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6989 
  6990 * Pure: name spaces have been refined, with significant changes of the
  6991 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6992 to extern(_table).  The plain name entry path is superceded by a
  6993 general 'naming' context, which also includes the 'policy' to produce
  6994 a fully qualified name and external accesses of a fully qualified
  6995 name; NameSpace.extend is superceded by context dependent
  6996 Sign.declare_name.  Several theory and proof context operations modify
  6997 the naming context.  Especially note Theory.restore_naming and
  6998 ProofContext.restore_naming to get back to a sane state; note that
  6999 Theory.add_path is no longer sufficient to recover from
  7000 Theory.absolute_path in particular.
  7001 
  7002 * Pure: new flags short_names (default false) and unique_names
  7003 (default true) for controlling output of qualified names.  If
  7004 short_names is set, names are printed unqualified.  If unique_names is
  7005 reset, the name prefix is reduced to the minimum required to achieve
  7006 the original result when interning again, even if there is an overlap
  7007 with earlier declarations.
  7008 
  7009 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  7010 now 'extend', and 'merge' gets an additional Pretty.pp argument
  7011 (useful for printing error messages).  INCOMPATIBILITY.
  7012 
  7013 * Pure: major reorganization of the theory context.  Type Sign.sg and
  7014 Theory.theory are now identified, referring to the universal
  7015 Context.theory (see Pure/context.ML).  Actual signature and theory
  7016 content is managed as theory data.  The old code and interfaces were
  7017 spread over many files and structures; the new arrangement introduces
  7018 considerable INCOMPATIBILITY to gain more clarity:
  7019 
  7020   Context -- theory management operations (name, identity, inclusion,
  7021     parents, ancestors, merge, etc.), plus generic theory data;
  7022 
  7023   Sign -- logical signature and syntax operations (declaring consts,
  7024     types, etc.), plus certify/read for common entities;
  7025 
  7026   Theory -- logical theory operations (stating axioms, definitions,
  7027     oracles), plus a copy of logical signature operations (consts,
  7028     types, etc.); also a few basic management operations (Theory.copy,
  7029     Theory.merge, etc.)
  7030 
  7031 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  7032 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  7033 for convenience -- they merely return the theory.
  7034 
  7035 * Pure: type Type.tsig is superceded by theory in most interfaces.
  7036 
  7037 * Pure: the Isar proof context type is already defined early in Pure
  7038 as Context.proof (note that ProofContext.context and Proof.context are
  7039 aliases, where the latter is the preferred name).  This enables other
  7040 Isabelle components to refer to that type even before Isar is present.
  7041 
  7042 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  7043 typeK, constK, axiomK, oracleK), but provide explicit operations for
  7044 any of these kinds.  For example, Sign.intern typeK is now
  7045 Sign.intern_type, Theory.hide_space Sign.typeK is now
  7046 Theory.hide_types.  Also note that former
  7047 Theory.hide_classes/types/consts are now
  7048 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  7049 internalize their arguments!  INCOMPATIBILITY.
  7050 
  7051 * Pure: get_thm interface (of PureThy and ProofContext) expects
  7052 datatype thmref (with constructors Name and NameSelection) instead of
  7053 plain string -- INCOMPATIBILITY;
  7054 
  7055 * Pure: cases produced by proof methods specify options, where NONE
  7056 means to remove case bindings -- INCOMPATIBILITY in
  7057 (RAW_)METHOD_CASES.
  7058 
  7059 * Pure: the following operations retrieve axioms or theorems from a
  7060 theory node or theory hierarchy, respectively:
  7061 
  7062   Theory.axioms_of: theory -> (string * term) list
  7063   Theory.all_axioms_of: theory -> (string * term) list
  7064   PureThy.thms_of: theory -> (string * thm) list
  7065   PureThy.all_thms_of: theory -> (string * thm) list
  7066 
  7067 * Pure: print_tac now outputs the goal through the trace channel.
  7068 
  7069 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  7070 Reference Toplevel.debug (default false) controls detailed printing
  7071 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  7072 controls execution profiling -- set to 1 for time and 2 for space
  7073 (both increase the runtime).
  7074 
  7075 * Isar session: The initial use of ROOT.ML is now always timed,
  7076 i.e. the log will show the actual process times, in contrast to the
  7077 elapsed wall-clock time that the outer shell wrapper produces.
  7078 
  7079 * Simplifier: improved handling of bound variables (nameless
  7080 representation, avoid allocating new strings).  Simprocs that invoke
  7081 the Simplifier recursively should use Simplifier.inherit_bounds to
  7082 avoid local name clashes.  Failure to do so produces warnings
  7083 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  7084 for further details.
  7085 
  7086 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  7087 bindings for all theorems stored within a given theory; this may help
  7088 in porting non-Isar theories to Isar ones, while keeping ML proof
  7089 scripts for the time being.
  7090 
  7091 * ML operator HTML.with_charset specifies the charset begin used for
  7092 generated HTML files.  For example:
  7093 
  7094   HTML.with_charset "utf-8" use_thy "Hebrew";
  7095   HTML.with_charset "utf-8" use_thy "Chinese";
  7096 
  7097 
  7098 *** System ***
  7099 
  7100 * Allow symlinks to all proper Isabelle executables (Isabelle,
  7101 isabelle, isatool etc.).
  7102 
  7103 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  7104 isatool doc, isatool mkdir, display_drafts etc.).
  7105 
  7106 * isatool usedir: option -f allows specification of the ML file to be
  7107 used by Isabelle; default is ROOT.ML.
  7108 
  7109 * New isatool version outputs the version identifier of the Isabelle
  7110 distribution being used.
  7111 
  7112 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  7113 (containing Boolean satisfiability problems) into Isabelle/HOL
  7114 theories.
  7115 
  7116 
  7117 
  7118 New in Isabelle2004 (April 2004)
  7119 --------------------------------
  7120 
  7121 *** General ***
  7122 
  7123 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  7124   Replaces linorder.ML.
  7125 
  7126 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  7127   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  7128   (\<a>...\<z>), are now considered normal letters, and can therefore
  7129   be used anywhere where an ASCII letter (a...zA...Z) has until
  7130   now. COMPATIBILITY: This obviously changes the parsing of some
  7131   terms, especially where a symbol has been used as a binder, say
  7132   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  7133   as an identifier.  Fix it by inserting a space around former
  7134   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  7135   existing theory and ML files.
  7136 
  7137 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  7138 
  7139 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  7140   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  7141   a normal (but invisible) letter. For multiple letter subscripts repeat
  7142   \<^isub> like this: x\<^isub>1\<^isub>2.
  7143 
  7144 * Pure: There are now sub-/superscripts that can span more than one
  7145   character. Text between \<^bsub> and \<^esub> is set in subscript in
  7146   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  7147   superscript. The new control characters are not identifier parts.
  7148 
  7149 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  7150   content of "..." to the latex file instead of \isacntrl... . The "..."
  7151   may consist of any printable characters excluding the end bracket >.
  7152 
  7153 * Pure: Using new Isar command "finalconsts" (or the ML functions
  7154   Theory.add_finals or Theory.add_finals_i) it is now possible to
  7155   declare constants "final", which prevents their being given a definition
  7156   later.  It is useful for constants whose behaviour is fixed axiomatically
  7157   rather than definitionally, such as the meta-logic connectives.
  7158 
  7159 * Pure: 'instance' now handles general arities with general sorts
  7160   (i.e. intersections of classes),
  7161 
  7162 * Presentation: generated HTML now uses a CSS style sheet to make layout
  7163   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  7164   It can be changed to alter the colors/layout of generated pages.
  7165 
  7166 
  7167 *** Isar ***
  7168 
  7169 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  7170   cut_tac, subgoal_tac and thin_tac:
  7171   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  7172     locales are no longer forced to write Isar proof scripts.
  7173     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  7174     emulations.
  7175   - INCOMPATIBILITY: names of variables to be instantiated may no
  7176     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  7177     This is consistent with the instantiation attribute "where".
  7178 
  7179 * Attributes "where" and "of":
  7180   - Now take type variables of instantiated theorem into account when reading
  7181     the instantiation string.  This fixes a bug that caused instantiated
  7182     theorems to have too special types in some circumstances.
  7183   - "where" permits explicit instantiations of type variables.
  7184 
  7185 * Calculation commands "moreover" and "also" no longer interfere with
  7186   current facts ("this"), admitting arbitrary combinations with "then"
  7187   and derived forms.
  7188 
  7189 * Locales:
  7190   - Goal statements involving the context element "includes" no longer
  7191     generate theorems with internal delta predicates (those ending on
  7192     "_axioms") in the premise.
  7193     Resolve particular premise with <locale>.intro to obtain old form.
  7194   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  7195     specification and "includes" elements in goal statement.
  7196   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  7197     [intro?] and [elim?] (respectively) by default.
  7198   - Experimental command for instantiation of locales in proof contexts:
  7199         instantiate <label>[<attrs>]: <loc>
  7200     Instantiates locale <loc> and adds all its theorems to the current context
  7201     taking into account their attributes.  Label and attrs are optional
  7202     modifiers, like in theorem declarations.  If present, names of
  7203     instantiated theorems are qualified with <label>, and the attributes
  7204     <attrs> are applied after any attributes these theorems might have already.
  7205       If the locale has assumptions, a chained fact of the form
  7206     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  7207     are derived.  The command does not support old-style locales declared
  7208     with "locale (open)".
  7209       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  7210 
  7211 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  7212   (Isar) contexts.
  7213 
  7214 
  7215 *** HOL ***
  7216 
  7217 * Proof import: new image HOL4 contains the imported library from
  7218   the HOL4 system with about 2500 theorems. It is imported by
  7219   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  7220   can be used like any other Isabelle image.  See
  7221   HOL/Import/HOL/README for more information.
  7222 
  7223 * Simplifier:
  7224   - Much improved handling of linear and partial orders.
  7225     Reasoners for linear and partial orders are set up for type classes
  7226     "linorder" and "order" respectively, and are added to the default simpset
  7227     as solvers.  This means that the simplifier can build transitivity chains
  7228     to solve goals from the assumptions.
  7229   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  7230     of blast or auto after simplification become unnecessary because the goal
  7231     is solved by simplification already.
  7232 
  7233 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  7234     all proved in axiomatic type classes for semirings, rings and fields.
  7235 
  7236 * Numerics:
  7237   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  7238     now formalized using the Ring_and_Field theory mentioned above.
  7239   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  7240     than before, because now they are set up once in a generic manner.
  7241   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  7242     Look for the general versions in Ring_and_Field (and Power if they concern
  7243     exponentiation).
  7244 
  7245 * Type "rat" of the rational numbers is now available in HOL-Complex.
  7246 
  7247 * Records:
  7248   - Record types are now by default printed with their type abbreviation
  7249     instead of the list of all field types. This can be configured via
  7250     the reference "print_record_type_abbr".
  7251   - Simproc "record_upd_simproc" for simplification of multiple updates added
  7252     (not enabled by default).
  7253   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  7254     EX x. x = sel r to True (not enabled by default).
  7255   - Tactic "record_split_simp_tac" to split and simplify records added.
  7256 
  7257 * 'specification' command added, allowing for definition by
  7258   specification.  There is also an 'ax_specification' command that
  7259   introduces the new constants axiomatically.
  7260 
  7261 * arith(_tac) is now able to generate counterexamples for reals as well.
  7262 
  7263 * HOL-Algebra: new locale "ring" for non-commutative rings.
  7264 
  7265 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  7266   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  7267 
  7268 * HOL-Matrix: a first theory for matrices in HOL with an application of
  7269   matrix theory to linear programming.
  7270 
  7271 * Unions and Intersections:
  7272   The latex output syntax of UN and INT has been changed
  7273   from "\Union x \in A. B" to "\Union_{x \in A} B"
  7274   i.e. the index formulae has become a subscript.
  7275   Similarly for "\Union x. B", and for \Inter instead of \Union.
  7276 
  7277 * Unions and Intersections over Intervals:
  7278   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  7279   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  7280   like in normal math, and corresponding versions for < and for intersection.
  7281 
  7282 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  7283   lexicographic dictonary ordering has been added as "lexord".
  7284 
  7285 * ML: the legacy theory structures Int and List have been removed. They had
  7286   conflicted with ML Basis Library structures having the same names.
  7287 
  7288 * 'refute' command added to search for (finite) countermodels.  Only works
  7289   for a fragment of HOL.  The installation of an external SAT solver is
  7290   highly recommended.  See "HOL/Refute.thy" for details.
  7291 
  7292 * 'quickcheck' command: Allows to find counterexamples by evaluating
  7293   formulae under an assignment of free variables to random values.
  7294   In contrast to 'refute', it can deal with inductive datatypes,
  7295   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  7296   for examples.
  7297 
  7298 
  7299 *** HOLCF ***
  7300 
  7301 * Streams now come with concatenation and are part of the HOLCF image
  7302 
  7303 
  7304 
  7305 New in Isabelle2003 (May 2003)
  7306 ------------------------------
  7307 
  7308 *** General ***
  7309 
  7310 * Provers/simplifier:
  7311 
  7312   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  7313     Assumptions are now subject to complete mutual simplification,
  7314     not just from left to right. The simplifier now preserves
  7315     the order of assumptions.
  7316 
  7317     Potential INCOMPATIBILITY:
  7318 
  7319     -- simp sometimes diverges where the old version did
  7320        not, e.g. invoking simp on the goal
  7321 
  7322         [| P (f x); y = x; f x = f y |] ==> Q
  7323 
  7324        now gives rise to the infinite reduction sequence
  7325 
  7326         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  7327 
  7328        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  7329        kind of problem.
  7330 
  7331     -- Tactics combining classical reasoner and simplification (such as auto)
  7332        are also affected by this change, because many of them rely on
  7333        simp. They may sometimes diverge as well or yield a different numbers
  7334        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  7335        in case of problems. Sometimes subsequent calls to the classical
  7336        reasoner will fail because a preceeding call to the simplifier too
  7337        eagerly simplified the goal, e.g. deleted redundant premises.
  7338 
  7339   - The simplifier trace now shows the names of the applied rewrite rules
  7340 
  7341   - You can limit the number of recursive invocations of the simplifier
  7342     during conditional rewriting (where the simplifie tries to solve the
  7343     conditions before applying the rewrite rule):
  7344     ML "simp_depth_limit := n"
  7345     where n is an integer. Thus you can force termination where previously
  7346     the simplifier would diverge.
  7347 
  7348   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  7349 
  7350   - No longer aborts on failed congruence proof.  Instead, the
  7351     congruence is ignored.
  7352 
  7353 * Pure: New generic framework for extracting programs from constructive
  7354   proofs. See HOL/Extraction.thy for an example instantiation, as well
  7355   as HOL/Extraction for some case studies.
  7356 
  7357 * Pure: The main goal of the proof state is no longer shown by default, only
  7358 the subgoals. This behaviour is controlled by a new flag.
  7359    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  7360 (ML: Proof.show_main_goal).
  7361 
  7362 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  7363 rules whose conclusion matches subgoal 1:
  7364       PG menu: Isabelle/Isar -> Show me -> matching rules
  7365 The rules are ordered by how closely they match the subgoal.
  7366 In particular, rules that solve a subgoal outright are displayed first
  7367 (or rather last, the way they are printed).
  7368 (ML: ProofGeneral.print_intros())
  7369 
  7370 * Pure: New flag trace_unify_fail causes unification to print
  7371 diagnostic information (PG: in trace buffer) when it fails. This is
  7372 useful for figuring out why single step proofs like rule, erule or
  7373 assumption failed.
  7374 
  7375 * Pure: Locale specifications now produce predicate definitions
  7376 according to the body of text (covering assumptions modulo local
  7377 definitions); predicate "loc_axioms" covers newly introduced text,
  7378 while "loc" is cumulative wrt. all included locale expressions; the
  7379 latter view is presented only on export into the global theory
  7380 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  7381 on the old view without predicates;
  7382 
  7383 * Pure: predefined locales "var" and "struct" are useful for sharing
  7384 parameters (as in CASL, for example); just specify something like
  7385 ``var x + var y + struct M'' as import;
  7386 
  7387 * Pure: improved thms_containing: proper indexing of facts instead of
  7388 raw theorems; check validity of results wrt. current name space;
  7389 include local facts of proof configuration (also covers active
  7390 locales), cover fixed variables in index; may use "_" in term
  7391 specification; an optional limit for the number of printed facts may
  7392 be given (the default is 40);
  7393 
  7394 * Pure: disallow duplicate fact bindings within new-style theory files
  7395 (batch-mode only);
  7396 
  7397 * Provers: improved induct method: assumptions introduced by case
  7398 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  7399 the goal statement); "foo" still refers to all facts collectively;
  7400 
  7401 * Provers: the function blast.overloaded has been removed: all constants
  7402 are regarded as potentially overloaded, which improves robustness in exchange
  7403 for slight decrease in efficiency;
  7404 
  7405 * Provers/linorder: New generic prover for transitivity reasoning over
  7406 linear orders.  Note: this prover is not efficient!
  7407 
  7408 * Isar: preview of problems to finish 'show' now produce an error
  7409 rather than just a warning (in interactive mode);
  7410 
  7411 
  7412 *** HOL ***
  7413 
  7414 * arith(_tac)
  7415 
  7416  - Produces a counter example if it cannot prove a goal.
  7417    Note that the counter example may be spurious if the goal is not a formula
  7418    of quantifier-free linear arithmetic.
  7419    In ProofGeneral the counter example appears in the trace buffer.
  7420 
  7421  - Knows about div k and mod k where k is a numeral of type nat or int.
  7422 
  7423  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  7424    linear arithmetic fails. This takes account of quantifiers and divisibility.
  7425    Presburger arithmetic can also be called explicitly via presburger(_tac).
  7426 
  7427 * simp's arithmetic capabilities have been enhanced a bit: it now
  7428 takes ~= in premises into account (by performing a case split);
  7429 
  7430 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  7431 are distributed over a sum of terms;
  7432 
  7433 * New tactic "trans_tac" and method "trans" instantiate
  7434 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  7435 "<=", "<" and "=").
  7436 
  7437 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  7438 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  7439 
  7440 * 'typedef' command has new option "open" to suppress the set
  7441 definition;
  7442 
  7443 * functions Min and Max on finite sets have been introduced (theory
  7444 Finite_Set);
  7445 
  7446 * attribute [symmetric] now works for relations as well; it turns
  7447 (x,y) : R^-1 into (y,x) : R, and vice versa;
  7448 
  7449 * induct over a !!-quantified statement (say !!x1..xn):
  7450   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  7451 
  7452 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  7453 %x. None. Warning: empty_def now refers to the previously hidden definition
  7454 of the empty set.
  7455 
  7456 * Algebra: formalization of classical algebra.  Intended as base for
  7457 any algebraic development in Isabelle.  Currently covers group theory
  7458 (up to Sylow's theorem) and ring theory (Universal Property of
  7459 Univariate Polynomials).  Contributions welcome;
  7460 
  7461 * GroupTheory: deleted, since its material has been moved to Algebra;
  7462 
  7463 * Complex: new directory of the complex numbers with numeric constants,
  7464 nonstandard complex numbers, and some complex analysis, standard and
  7465 nonstandard (Jacques Fleuriot);
  7466 
  7467 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  7468 
  7469 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  7470 Fleuriot);
  7471 
  7472 * Real/HahnBanach: updated and adapted to locales;
  7473 
  7474 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  7475 Gray and Kramer);
  7476 
  7477 * UNITY: added the Meier-Sanders theory of progress sets;
  7478 
  7479 * MicroJava: bytecode verifier and lightweight bytecode verifier
  7480 as abstract algorithms, instantiated to the JVM;
  7481 
  7482 * Bali: Java source language formalization. Type system, operational
  7483 semantics, axiomatic semantics. Supported language features:
  7484 classes, interfaces, objects,virtual methods, static methods,
  7485 static/instance fields, arrays, access modifiers, definite
  7486 assignment, exceptions.
  7487 
  7488 
  7489 *** ZF ***
  7490 
  7491 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  7492 universe, etc.);
  7493 
  7494 * Main ZF: virtually all theories converted to new-style format;
  7495 
  7496 
  7497 *** ML ***
  7498 
  7499 * Pure: Tactic.prove provides sane interface for internal proofs;
  7500 omits the infamous "standard" operation, so this is more appropriate
  7501 than prove_goalw_cterm in many situations (e.g. in simprocs);
  7502 
  7503 * Pure: improved error reporting of simprocs;
  7504 
  7505 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  7506 up simprocs;
  7507 
  7508 
  7509 *** Document preparation ***
  7510 
  7511 * uses \par instead of \\ for line breaks in theory text. This may
  7512 shift some page breaks in large documents. To get the old behaviour
  7513 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  7514 
  7515 * minimized dependencies of isabelle.sty and isabellesym.sty on
  7516 other packages
  7517 
  7518 * \<euro> now needs package babel/greek instead of marvosym (which
  7519 broke \Rightarrow)
  7520 
  7521 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  7522 textcomp package)
  7523 
  7524 
  7525 
  7526 New in Isabelle2002 (March 2002)
  7527 --------------------------------
  7528 
  7529 *** Document preparation ***
  7530 
  7531 * greatly simplified document preparation setup, including more
  7532 graceful interpretation of isatool usedir -i/-d/-D options, and more
  7533 instructive isatool mkdir; users should basically be able to get
  7534 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  7535 users may run a separate document processing stage manually like this:
  7536 "isatool usedir -D output HOL Test && isatool document Test/output";
  7537 
  7538 * theory dependency graph may now be incorporated into documents;
  7539 isatool usedir -g true will produce session_graph.eps/.pdf for use
  7540 with \includegraphics of LaTeX;
  7541 
  7542 * proper spacing of consecutive markup elements, especially text
  7543 blocks after section headings;
  7544 
  7545 * support bold style (for single symbols only), input syntax is like
  7546 this: "\<^bold>\<alpha>" or "\<^bold>A";
  7547 
  7548 * \<bullet> is now output as bold \cdot by default, which looks much
  7549 better in printed text;
  7550 
  7551 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  7552 note that these symbols are currently unavailable in Proof General /
  7553 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  7554 
  7555 * isatool latex no longer depends on changed TEXINPUTS, instead
  7556 isatool document copies the Isabelle style files to the target
  7557 location;
  7558 
  7559 
  7560 *** Isar ***
  7561 
  7562 * Pure/Provers: improved proof by cases and induction;
  7563   - 'case' command admits impromptu naming of parameters (such as
  7564     "case (Suc n)");
  7565   - 'induct' method divinates rule instantiation from the inductive
  7566     claim; no longer requires excessive ?P bindings for proper
  7567     instantiation of cases;
  7568   - 'induct' method properly enumerates all possibilities of set/type
  7569     rules; as a consequence facts may be also passed through *type*
  7570     rules without further ado;
  7571   - 'induct' method now derives symbolic cases from the *rulified*
  7572     rule (before it used to rulify cases stemming from the internal
  7573     atomized version); this means that the context of a non-atomic
  7574     statement becomes is included in the hypothesis, avoiding the
  7575     slightly cumbersome show "PROP ?case" form;
  7576   - 'induct' may now use elim-style induction rules without chaining
  7577     facts, using ``missing'' premises from the goal state; this allows
  7578     rules stemming from inductive sets to be applied in unstructured
  7579     scripts, while still benefitting from proper handling of non-atomic
  7580     statements; NB: major inductive premises need to be put first, all
  7581     the rest of the goal is passed through the induction;
  7582   - 'induct' proper support for mutual induction involving non-atomic
  7583     rule statements (uses the new concept of simultaneous goals, see
  7584     below);
  7585   - append all possible rule selections, but only use the first
  7586     success (no backtracking);
  7587   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  7588   - undeclared rule case names default to numbers 1, 2, 3, ...;
  7589   - added 'print_induct_rules' (covered by help item in recent Proof
  7590     General versions);
  7591   - moved induct/cases attributes to Pure, methods to Provers;
  7592   - generic method setup instantiated for FOL and HOL;
  7593 
  7594 * Pure: support multiple simultaneous goal statements, for example
  7595 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  7596 meta-level mechanism, this acts as if several individual goals had
  7597 been stated separately; in particular common proof methods need to be
  7598 repeated in order to cover all claims; note that a single elimination
  7599 step is *not* sufficient to establish the two conjunctions, so this
  7600 fails:
  7601 
  7602   assume "A & B" then have A and B ..   (*".." fails*)
  7603 
  7604 better use "obtain" in situations as above; alternative refer to
  7605 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  7606 
  7607 * Pure: proper integration with ``locales''; unlike the original
  7608 version by Florian Kammller, Isar locales package high-level proof
  7609 contexts rather than raw logical ones (e.g. we admit to include
  7610 attributes everywhere); operations on locales include merge and
  7611 rename; support for implicit arguments (``structures''); simultaneous
  7612 type-inference over imports and text; see also HOL/ex/Locales.thy for
  7613 some examples;
  7614 
  7615 * Pure: the following commands have been ``localized'', supporting a
  7616 target locale specification "(in name)": 'lemma', 'theorem',
  7617 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  7618 stored both within the locale and at the theory level (exported and
  7619 qualified by the locale name);
  7620 
  7621 * Pure: theory goals may now be specified in ``long'' form, with
  7622 ad-hoc contexts consisting of arbitrary locale elements. for example
  7623 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  7624 definitions may be given, too); the result is a meta-level rule with
  7625 the context elements being discharged in the obvious way;
  7626 
  7627 * Pure: new proof command 'using' allows to augment currently used
  7628 facts after a goal statement ('using' is syntactically analogous to
  7629 'apply', but acts on the goal's facts only); this allows chained facts
  7630 to be separated into parts given before and after a claim, as in
  7631 ``from a and b have C using d and e <proof>'';
  7632 
  7633 * Pure: renamed "antecedent" case to "rule_context";
  7634 
  7635 * Pure: new 'judgment' command records explicit information about the
  7636 object-logic embedding (used by several tools internally); no longer
  7637 use hard-wired "Trueprop";
  7638 
  7639 * Pure: added 'corollary' command;
  7640 
  7641 * Pure: fixed 'token_translation' command;
  7642 
  7643 * Pure: removed obsolete 'exported' attribute;
  7644 
  7645 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  7646 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  7647 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  7648 
  7649 * Pure: method 'atomize' presents local goal premises as object-level
  7650 statements (atomic meta-level propositions); setup controlled via
  7651 rewrite rules declarations of 'atomize' attribute; example
  7652 application: 'induct' method with proper rule statements in improper
  7653 proof *scripts*;
  7654 
  7655 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  7656 now consider the syntactic context of assumptions, giving a better
  7657 chance to get type-inference of the arguments right (this is
  7658 especially important for locales);
  7659 
  7660 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  7661 mode;
  7662 
  7663 * Pure/obtain: the formal conclusion "thesis", being marked as
  7664 ``internal'', may no longer be reference directly in the text;
  7665 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  7666 situations;
  7667 
  7668 * Pure: generic 'sym' attribute which declares a rule both as pure
  7669 'elim?' and for the 'symmetric' operation;
  7670 
  7671 * Pure: marginal comments ``--'' may now occur just anywhere in the
  7672 text; the fixed correlation with particular command syntax has been
  7673 discontinued;
  7674 
  7675 * Pure: new method 'rules' is particularly well-suited for proof
  7676 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  7677 but often produces more compact proof terms with less detours;
  7678 
  7679 * Pure/Provers/classical: simplified integration with pure rule
  7680 attributes and methods; the classical "intro?/elim?/dest?"
  7681 declarations coincide with the pure ones; the "rule" method no longer
  7682 includes classically swapped intros; "intro" and "elim" methods no
  7683 longer pick rules from the context; also got rid of ML declarations
  7684 AddXIs/AddXEs/AddXDs; all of this has some potential for
  7685 INCOMPATIBILITY;
  7686 
  7687 * Provers/classical: attribute 'swapped' produces classical inversions
  7688 of introduction rules;
  7689 
  7690 * Provers/simplifier: 'simplified' attribute may refer to explicit
  7691 rules instead of full simplifier context; 'iff' attribute handles
  7692 conditional rules;
  7693 
  7694 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  7695 
  7696 * HOL: 'recdef' now fails on unfinished automated proofs, use
  7697 "(permissive)" option to recover old behavior;
  7698 
  7699 * HOL: 'inductive' no longer features separate (collective) attributes
  7700 for 'intros' (was found too confusing);
  7701 
  7702 * HOL: properly declared induction rules less_induct and
  7703 wf_induct_rule;
  7704 
  7705 
  7706 *** HOL ***
  7707 
  7708 * HOL: moved over to sane numeral syntax; the new policy is as
  7709 follows:
  7710 
  7711   - 0 and 1 are polymorphic constants, which are defined on any
  7712   numeric type (nat, int, real etc.);
  7713 
  7714   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  7715   binary representation internally;
  7716 
  7717   - type nat has special constructor Suc, and generally prefers Suc 0
  7718   over 1::nat and Suc (Suc 0) over 2::nat;
  7719 
  7720 This change may cause significant problems of INCOMPATIBILITY; here
  7721 are some hints on converting existing sources:
  7722 
  7723   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  7724   entities, so expressions involving "-" (unary or binary minus) need
  7725   to be spaced properly;
  7726 
  7727   - existing occurrences of "1" may need to be constraint "1::nat" or
  7728   even replaced by Suc 0; similar for old "2";
  7729 
  7730   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  7731 
  7732   - remove all special provisions on numerals in proofs;
  7733 
  7734 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  7735 representation (depends on bin_arith_simps in the default context);
  7736 
  7737 * HOL: symbolic syntax for x^2 (numeral 2);
  7738 
  7739 * HOL: the class of all HOL types is now called "type" rather than
  7740 "term"; INCOMPATIBILITY, need to adapt references to this type class
  7741 in axclass/classes, instance/arities, and (usually rare) occurrences
  7742 in typings (of consts etc.); internally the class is called
  7743 "HOL.type", ML programs should refer to HOLogic.typeS;
  7744 
  7745 * HOL/record package improvements:
  7746   - new derived operations "fields" to build a partial record section,
  7747     "extend" to promote a fixed record to a record scheme, and
  7748     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  7749     declared as simp by default;
  7750   - shared operations ("more", "fields", etc.) now need to be always
  7751     qualified) --- potential INCOMPATIBILITY;
  7752   - removed "make_scheme" operations (use "make" with "extend") --
  7753     INCOMPATIBILITY;
  7754   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  7755   - provides cases/induct rules for use with corresponding Isar
  7756     methods (for concrete records, record schemes, concrete more
  7757     parts, and schematic more parts -- in that order);
  7758   - internal definitions directly based on a light-weight abstract
  7759     theory of product types over typedef rather than datatype;
  7760 
  7761 * HOL: generic code generator for generating executable ML code from
  7762 specifications; specific support for HOL constructs such as inductive
  7763 datatypes and sets, as well as recursive functions; can be invoked
  7764 via 'generate_code' theory section;
  7765 
  7766 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  7767 
  7768 * HOL: consolidated and renamed several theories.  In particular:
  7769         Ord.thy has been absorbed into HOL.thy
  7770         String.thy has been absorbed into List.thy
  7771 
  7772 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  7773 (beware of argument permutation!);
  7774 
  7775 * HOL: linorder_less_split superseded by linorder_cases;
  7776 
  7777 * HOL/List: "nodups" renamed to "distinct";
  7778 
  7779 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  7780 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  7781   - Ex_def has changed, now need to use some_eq_ex
  7782 
  7783 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  7784 in this (rare) case use:
  7785 
  7786   delSWrapper "split_all_tac"
  7787   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  7788 
  7789 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  7790 MAY FAIL;
  7791 
  7792 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  7793 Isabelle's type classes, ^ on functions and relations has too general
  7794 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  7795 necessary to attach explicit type constraints;
  7796 
  7797 * HOL/Relation: the prefix name of the infix "O" has been changed from
  7798 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  7799 renamed accordingly (eg "compI" -> "rel_compI").
  7800 
  7801 * HOL: syntax translations now work properly with numerals and records
  7802 expressions;
  7803 
  7804 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  7805 of "lam" -- INCOMPATIBILITY;
  7806 
  7807 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  7808 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  7809 renamed "Product_Type.unit";
  7810 
  7811 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  7812 
  7813 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  7814 the "cases" method);
  7815 
  7816 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  7817 Florian Kammller);
  7818 
  7819 * HOL/IMP: updated and converted to new-style theory format; several
  7820 parts turned into readable document, with proper Isar proof texts and
  7821 some explanations (by Gerwin Klein);
  7822 
  7823 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  7824 
  7825 * HOL-Hyperreal is now a logic image;
  7826 
  7827 
  7828 *** HOLCF ***
  7829 
  7830 * Isar: consts/constdefs supports mixfix syntax for continuous
  7831 operations;
  7832 
  7833 * Isar: domain package adapted to new-style theory format, e.g. see
  7834 HOLCF/ex/Dnat.thy;
  7835 
  7836 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  7837 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  7838 lift.induct_tac, always use UU instead of Undef;
  7839 
  7840 * HOLCF/IMP: updated and converted to new-style theory;
  7841 
  7842 
  7843 *** ZF ***
  7844 
  7845 * Isar: proper integration of logic-specific tools and packages,
  7846 including theory commands '(co)inductive', '(co)datatype',
  7847 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  7848 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7849 
  7850 * theory Main no longer includes AC; for the Axiom of Choice, base
  7851 your theory on Main_ZFC;
  7852 
  7853 * the integer library now covers quotients and remainders, with many
  7854 laws relating division to addition, multiplication, etc.;
  7855 
  7856 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7857 typeless version of the formalism;
  7858 
  7859 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7860 format;
  7861 
  7862 * ZF/Induct: new directory for examples of inductive definitions,
  7863 including theory Multiset for multiset orderings; converted to
  7864 new-style theory format;
  7865 
  7866 * ZF: many new theorems about lists, ordinals, etc.;
  7867 
  7868 
  7869 *** General ***
  7870 
  7871 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7872 variable proof controls level of detail: 0 = no proofs (only oracle
  7873 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7874 also ref manual for further ML interfaces;
  7875 
  7876 * Pure/axclass: removed obsolete ML interface
  7877 goal_subclass/goal_arity;
  7878 
  7879 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7880 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7881 separate tokens, so expressions involving minus need to be spaced
  7882 properly;
  7883 
  7884 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7885 rather than "infixl" or "infixr";
  7886 
  7887 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7888 sort constraint specifications in type inference; e.g. "x::_::foo"
  7889 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7890 type variable);
  7891 
  7892 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7893 control output of nested => (types); the default behavior is
  7894 "type_brackets";
  7895 
  7896 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7897 tokens into AST constants;
  7898 
  7899 * Pure/syntax: prefer later declarations of translations and print
  7900 translation functions; potential INCOMPATIBILITY: need to reverse
  7901 multiple declarations for same syntax element constant;
  7902 
  7903 * Pure/show_hyps reset by default (in accordance to existing Isar
  7904 practice);
  7905 
  7906 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7907 addSafter;
  7908 
  7909 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7910 as well;
  7911 
  7912 * system: tested support for MacOS X; should be able to get Isabelle +
  7913 Proof General to work in a plain Terminal after installing Poly/ML
  7914 (e.g. from the Isabelle distribution area) and GNU bash alone
  7915 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7916 support requires further installations, e.g. from
  7917 http://fink.sourceforge.net/);
  7918 
  7919 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7920 
  7921 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7922 of 40 MB), cf. ML_OPTIONS;
  7923 
  7924 * system: Proof General keywords specification is now part of the
  7925 Isabelle distribution (see etc/isar-keywords.el);
  7926 
  7927 * system: support for persistent Proof General sessions (refrain from
  7928 outdating all loaded theories on startup); user may create writable
  7929 logic images like this: ``isabelle -q HOL Test'';
  7930 
  7931 * system: smart selection of Isabelle process versus Isabelle
  7932 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7933 run both "isabelle" and "Isabelle" even if file names are badly
  7934 damaged (executable inspects the case of the first letter of its own
  7935 name); added separate "isabelle-process" and "isabelle-interface";
  7936 
  7937 * system: refrain from any attempt at filtering input streams; no
  7938 longer support ``8bit'' encoding of old isabelle font, instead proper
  7939 iso-latin characters may now be used; the related isatools
  7940 "symbolinput" and "nonascii" have disappeared as well;
  7941 
  7942 * system: removed old "xterm" interface (the print modes "xterm" and
  7943 "xterm_color" are still available for direct use in a suitable
  7944 terminal);
  7945 
  7946 
  7947 
  7948 New in Isabelle99-2 (February 2001)
  7949 -----------------------------------
  7950 
  7951 *** Overview of INCOMPATIBILITIES ***
  7952 
  7953 * HOL: please note that theories in the Library and elsewhere often use the
  7954 new-style (Isar) format; to refer to their theorems in an ML script you must
  7955 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7956 
  7957 * HOL: inductive package no longer splits induction rule aggressively,
  7958 but only as far as specified by the introductions given; the old
  7959 format may be recovered via ML function complete_split_rule or attribute
  7960 'split_rule (complete)';
  7961 
  7962 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7963 gfp_Tarski to gfp_unfold;
  7964 
  7965 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7966 
  7967 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7968 relation); infix "^^" has been renamed "``"; infix "``" has been
  7969 renamed "`"; "univalent" has been renamed "single_valued";
  7970 
  7971 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7972 operation;
  7973 
  7974 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7975 
  7976 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7977 
  7978 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7979 consequence, it is no longer monotonic wrt. the local goal context
  7980 (which is now passed through the inductive cases);
  7981 
  7982 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7983 \<gg> to \<ggreater>;
  7984 
  7985 
  7986 *** Document preparation ***
  7987 
  7988 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7989 available: are "it" for near math-mode best-style output, "sl" for
  7990 slanted text style, and "tt" for plain type-writer; if no
  7991 \isabellestyle command is given, output is according to slanted
  7992 type-writer);
  7993 
  7994 * support sub/super scripts (for single symbols only), input syntax is
  7995 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7996 
  7997 * some more standard symbols; see Appendix A of the system manual for
  7998 the complete list of symbols defined in isabellesym.sty;
  7999 
  8000 * improved isabelle style files; more abstract symbol implementation
  8001 (should now use \isamath{...} and \isatext{...} in custom symbol
  8002 definitions);
  8003 
  8004 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  8005 state; Note that presentation of goal states does not conform to
  8006 actual human-readable proof documents.  Please do not include goal
  8007 states into document output unless you really know what you are doing!
  8008 
  8009 * proper indentation of antiquoted output with proportional LaTeX
  8010 fonts;
  8011 
  8012 * no_document ML operator temporarily disables LaTeX document
  8013 generation;
  8014 
  8015 * isatool unsymbolize tunes sources for plain ASCII communication;
  8016 
  8017 
  8018 *** Isar ***
  8019 
  8020 * Pure: Isar now suffers initial goal statements to contain unbound
  8021 schematic variables (this does not conform to actual readable proof
  8022 documents, due to unpredictable outcome and non-compositional proof
  8023 checking); users who know what they are doing may use schematic goals
  8024 for Prolog-style synthesis of proven results;
  8025 
  8026 * Pure: assumption method (an implicit finishing) now handles actual
  8027 rules as well;
  8028 
  8029 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  8030 initial goal, declare "that" only as Pure intro (only for single
  8031 steps); the "that" rule assumption may now be involved in implicit
  8032 finishing, thus ".." becomes a feasible for trivial obtains;
  8033 
  8034 * Pure: default proof step now includes 'intro_classes'; thus trivial
  8035 instance proofs may be performed by "..";
  8036 
  8037 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  8038 statements as well;
  8039 
  8040 * Pure: more robust selection of calculational rules;
  8041 
  8042 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  8043 rule (as well as the assumption rule);
  8044 
  8045 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  8046 lemmas, using the graph browser tool;
  8047 
  8048 * Pure: predict failure of "show" in interactive mode;
  8049 
  8050 * Pure: 'thms_containing' now takes actual terms as arguments;
  8051 
  8052 * HOL: improved method 'induct' --- now handles non-atomic goals
  8053 (potential INCOMPATIBILITY); tuned error handling;
  8054 
  8055 * HOL: cases and induct rules now provide explicit hints about the
  8056 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  8057 any remaining facts are inserted into the goal verbatim;
  8058 
  8059 * HOL: local contexts (aka cases) may now contain term bindings as
  8060 well; the 'cases' and 'induct' methods new provide a ?case binding for
  8061 the result to be shown in each case;
  8062 
  8063 * HOL: added 'recdef_tc' command;
  8064 
  8065 * isatool convert assists in eliminating legacy ML scripts;
  8066 
  8067 
  8068 *** HOL ***
  8069 
  8070 * HOL/Library: a collection of generic theories to be used together
  8071 with main HOL; the theory loader path already includes this directory
  8072 by default; the following existing theories have been moved here:
  8073 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  8074 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  8075 
  8076 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  8077 modelling and verification task performed in Isabelle/HOL +
  8078 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  8079 
  8080 * HOL/Algebra: special summation operator SUM no longer exists, it has
  8081 been replaced by setsum; infix 'assoc' now has priority 50 (like
  8082 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  8083 'domain', this makes the theory consistent with mathematical
  8084 literature;
  8085 
  8086 * HOL basics: added overloaded operations "inverse" and "divide"
  8087 (infix "/"), syntax for generic "abs" operation, generic summation
  8088 operator \<Sum>;
  8089 
  8090 * HOL/typedef: simplified package, provide more useful rules (see also
  8091 HOL/subset.thy);
  8092 
  8093 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  8094 now expressed as a proper nested rule (old-style tactic scripts may
  8095 require atomize_strip_tac to cope with non-atomic premises);
  8096 
  8097 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  8098 to "split_conv" (old name still available for compatibility);
  8099 
  8100 * HOL: improved concrete syntax for strings (e.g. allows translation
  8101 rules with string literals);
  8102 
  8103 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  8104  and Fleuriot's mechanization of analysis, including the transcendental
  8105  functions for the reals;
  8106 
  8107 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  8108 
  8109 
  8110 *** CTT ***
  8111 
  8112 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  8113 "lam" is displayed as TWO lambda-symbols
  8114 
  8115 * CTT: theory Main now available, containing everything (that is, Bool
  8116 and Arith);
  8117 
  8118 
  8119 *** General ***
  8120 
  8121 * Pure: the Simplifier has been implemented properly as a derived rule
  8122 outside of the actual kernel (at last!); the overall performance
  8123 penalty in practical applications is about 50%, while reliability of
  8124 the Isabelle inference kernel has been greatly improved;
  8125 
  8126 * print modes "brackets" and "no_brackets" control output of nested =>
  8127 (types) and ==> (props); the default behaviour is "brackets";
  8128 
  8129 * Provers: fast_tac (and friends) now handle actual object-logic rules
  8130 as assumptions as well;
  8131 
  8132 * system: support Poly/ML 4.0;
  8133 
  8134 * system: isatool install handles KDE version 1 or 2;
  8135 
  8136 
  8137 
  8138 New in Isabelle99-1 (October 2000)
  8139 ----------------------------------
  8140 
  8141 *** Overview of INCOMPATIBILITIES ***
  8142 
  8143 * HOL: simplification of natural numbers is much changed; to partly
  8144 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  8145 issue the following ML commands:
  8146 
  8147   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  8148   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  8149 
  8150 * HOL: simplification no longer dives into case-expressions; this is
  8151 controlled by "t.weak_case_cong" for each datatype t;
  8152 
  8153 * HOL: nat_less_induct renamed to less_induct;
  8154 
  8155 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  8156 fixsome to patch .thy and .ML sources automatically;
  8157 
  8158   select_equality  -> some_equality
  8159   select_eq_Ex     -> some_eq_ex
  8160   selectI2EX       -> someI2_ex
  8161   selectI2         -> someI2
  8162   selectI          -> someI
  8163   select1_equality -> some1_equality
  8164   Eps_sym_eq       -> some_sym_eq_trivial
  8165   Eps_eq           -> some_eq_trivial
  8166 
  8167 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  8168 
  8169 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  8170 instead);
  8171 
  8172 * HOL: the recursion equations generated by 'recdef' are now called
  8173 f.simps instead of f.rules;
  8174 
  8175 * HOL: qed_spec_mp now also handles bounded ALL as well;
  8176 
  8177 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  8178 sometimes be needed;
  8179 
  8180 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  8181 
  8182 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  8183 
  8184 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  8185 product is now "<*>" instead of "Times"; the lexicographic product is
  8186 now "<*lex*>" instead of "**";
  8187 
  8188 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  8189 of main HOL, but was unused); better use HOL's datatype package;
  8190 
  8191 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  8192 the old syntax may be recovered as follows:
  8193 
  8194   syntax (symbols)
  8195     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  8196       (infixl "\\<oplus>" 100)
  8197 
  8198 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  8199 
  8200 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  8201 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  8202 internally;
  8203 
  8204 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  8205 changed from A/r to A//r;
  8206 
  8207 * ZF: new treatment of arithmetic (nat & int) may break some old
  8208 proofs;
  8209 
  8210 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  8211 rulify -> rule_format, elimify -> elim_format, ...);
  8212 
  8213 * Isar/Provers: intro/elim/dest attributes changed; renamed
  8214 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  8215 should have to change intro!! to intro? only); replaced "delrule" by
  8216 "rule del";
  8217 
  8218 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  8219 
  8220 * Provers: strengthened force_tac by using new first_best_tac;
  8221 
  8222 * LaTeX document preparation: several changes of isabelle.sty (see
  8223 lib/texinputs);
  8224 
  8225 
  8226 *** Document preparation ***
  8227 
  8228 * formal comments (text blocks etc.) in new-style theories may now
  8229 contain antiquotations of thm/prop/term/typ/text to be presented
  8230 according to latex print mode; concrete syntax is like this:
  8231 @{term[show_types] "f(x) = a + x"};
  8232 
  8233 * isatool mkdir provides easy setup of Isabelle session directories,
  8234 including proper document sources;
  8235 
  8236 * generated LaTeX sources are now deleted after successful run
  8237 (isatool document -c); may retain a copy somewhere else via -D option
  8238 of isatool usedir;
  8239 
  8240 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  8241 style files, achieving self-contained LaTeX sources and simplifying
  8242 LaTeX debugging;
  8243 
  8244 * old-style theories now produce (crude) LaTeX output as well;
  8245 
  8246 * browser info session directories are now self-contained (may be put
  8247 on WWW server seperately); improved graphs of nested sessions; removed
  8248 graph for 'all sessions';
  8249 
  8250 * several improvements in isabelle style files; \isabellestyle{it}
  8251 produces fake math mode output; \isamarkupheader is now \section by
  8252 default; see lib/texinputs/isabelle.sty etc.;
  8253 
  8254 
  8255 *** Isar ***
  8256 
  8257 * Isar/Pure: local results and corresponding term bindings are now
  8258 subject to Hindley-Milner polymorphism (similar to ML); this
  8259 accommodates incremental type-inference very nicely;
  8260 
  8261 * Isar/Pure: new derived language element 'obtain' supports
  8262 generalized existence reasoning;
  8263 
  8264 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  8265 support accumulation of results, without applying any rules yet;
  8266 useful to collect intermediate results without explicit name
  8267 references, and for use with transitivity rules with more than 2
  8268 premises;
  8269 
  8270 * Isar/Pure: scalable support for case-analysis type proofs: new
  8271 'case' language element refers to local contexts symbolically, as
  8272 produced by certain proof methods; internally, case names are attached
  8273 to theorems as "tags";
  8274 
  8275 * Isar/Pure: theory command 'hide' removes declarations from
  8276 class/type/const name spaces;
  8277 
  8278 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  8279 indicate potential overloading;
  8280 
  8281 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  8282 
  8283 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  8284 "{a,b,c}" instead of {a,b,c};
  8285 
  8286 * Isar/Pure now provides its own version of intro/elim/dest
  8287 attributes; useful for building new logics, but beware of confusion
  8288 with the version in Provers/classical;
  8289 
  8290 * Isar/Pure: the local context of (non-atomic) goals is provided via
  8291 case name 'antecedent';
  8292 
  8293 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  8294 to the current context is now done automatically);
  8295 
  8296 * Isar/Pure: theory command 'method_setup' provides a simple interface
  8297 for definining proof methods in ML;
  8298 
  8299 * Isar/Provers: intro/elim/dest attributes changed; renamed
  8300 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  8301 most cases, one should have to change intro!! to intro? only);
  8302 replaced "delrule" by "rule del";
  8303 
  8304 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  8305 'symmetric' attribute (the latter supercedes [RS sym]);
  8306 
  8307 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  8308 method modifier); 'simp' method: 'only:' modifier removes loopers as
  8309 well (including splits);
  8310 
  8311 * Isar/Provers: Simplifier and Classical methods now support all kind
  8312 of modifiers used in the past, including 'cong', 'iff', etc.
  8313 
  8314 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  8315 of Simplifier and Classical reasoner);
  8316 
  8317 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  8318 now support named cases; major packages (inductive, datatype, primrec,
  8319 recdef) support case names and properly name parameters;
  8320 
  8321 * Isar/HOL: new transitivity rules for substitution in inequalities --
  8322 monotonicity conditions are extracted to be proven at end of
  8323 calculations;
  8324 
  8325 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  8326 method anyway;
  8327 
  8328 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  8329 split_if split_if_asm; datatype package provides theorems foo.splits =
  8330 foo.split foo.split_asm for each datatype;
  8331 
  8332 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  8333 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  8334 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  8335 use "(cases (simplified))" method in proper proof texts);
  8336 
  8337 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  8338 
  8339 * Isar: names of theorems etc. may be natural numbers as well;
  8340 
  8341 * Isar: 'pr' command: optional arguments for goals_limit and
  8342 ProofContext.prems_limit; no longer prints theory contexts, but only
  8343 proof states;
  8344 
  8345 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  8346 additional print modes to be specified; e.g. "pr(latex)" will print
  8347 proof state according to the Isabelle LaTeX style;
  8348 
  8349 * Isar: improved support for emulating tactic scripts, including proof
  8350 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  8351 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  8352 (for HOL datatypes);
  8353 
  8354 * Isar: simplified (more robust) goal selection of proof methods: 1st
  8355 goal, all goals, or explicit goal specifier (tactic emulation); thus
  8356 'proof method scripts' have to be in depth-first order;
  8357 
  8358 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  8359 
  8360 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  8361 should instead use individual commands for printing items
  8362 (print_commands, print_methods etc.);
  8363 
  8364 * Isar: added 'nothing' --- the empty list of theorems;
  8365 
  8366 
  8367 *** HOL ***
  8368 
  8369 * HOL/MicroJava: formalization of a fragment of Java, together with a
  8370 corresponding virtual machine and a specification of its bytecode
  8371 verifier and a lightweight bytecode verifier, including proofs of
  8372 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  8373 Cornelia Pusch (see also the homepage of project Bali at
  8374 http://isabelle.in.tum.de/Bali/);
  8375 
  8376 * HOL/Algebra: new theory of rings and univariate polynomials, by
  8377 Clemens Ballarin;
  8378 
  8379 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  8380 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  8381 Rasmussen;
  8382 
  8383 * HOL/Lattice: fundamental concepts of lattice theory and order
  8384 structures, including duals, properties of bounds versus algebraic
  8385 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  8386 Theorem for complete lattices etc.; may also serve as a demonstration
  8387 for abstract algebraic reasoning using axiomatic type classes, and
  8388 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  8389 
  8390 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  8391 von Oheimb;
  8392 
  8393 * HOL/IMPP: extension of IMP with local variables and mutually
  8394 recursive procedures, by David von Oheimb;
  8395 
  8396 * HOL/Lambda: converted into new-style theory and document;
  8397 
  8398 * HOL/ex/Multiquote: example of multiple nested quotations and
  8399 anti-quotations -- basically a generalized version of de-Bruijn
  8400 representation; very useful in avoiding lifting of operations;
  8401 
  8402 * HOL/record: added general record equality rule to simpset; fixed
  8403 select-update simplification procedure to handle extended records as
  8404 well; admit "r" as field name;
  8405 
  8406 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  8407 other numeric types and also as the identity of groups, rings, etc.;
  8408 
  8409 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  8410 Types nat and int belong to this axclass;
  8411 
  8412 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  8413    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  8414    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  8415   two terms #m*u and #n*u are replaced by #(m+n)*u
  8416     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  8417   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  8418     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  8419 
  8420 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  8421 powerful prover for predicate logic but knows nothing of clasets; see
  8422 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  8423 
  8424 * HOL: new version of "case_tac" subsumes both boolean case split and
  8425 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  8426 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  8427 
  8428 * HOL: simplification no longer dives into case-expressions: only the
  8429 selector expression is simplified, but not the remaining arms; to
  8430 enable full simplification of case-expressions for datatype t, you may
  8431 remove t.weak_case_cong from the simpset, either globally (Delcongs
  8432 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  8433 
  8434 * HOL/recdef: the recursion equations generated by 'recdef' for
  8435 function 'f' are now called f.simps instead of f.rules; if all
  8436 termination conditions are proved automatically, these simplification
  8437 rules are added to the simpset, as in primrec; rules may be named
  8438 individually as well, resulting in a separate list of theorems for
  8439 each equation;
  8440 
  8441 * HOL/While is a new theory that provides a while-combinator. It
  8442 permits the definition of tail-recursive functions without the
  8443 provision of a termination measure. The latter is necessary once the
  8444 invariant proof rule for while is applied.
  8445 
  8446 * HOL: new (overloaded) notation for the set of elements below/above
  8447 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  8448 
  8449 * HOL: theorems impI, allI, ballI bound as "strip";
  8450 
  8451 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  8452 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  8453 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  8454 
  8455 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  8456 
  8457 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  8458 main HOL, but was unused);
  8459 
  8460 * HOL: fewer consts declared as global (e.g. have to refer to
  8461 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  8462 
  8463 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  8464 in case of overlap with user translations (e.g. judgements over
  8465 tuples); (note that the underlying logical represenation is still
  8466 bogus);
  8467 
  8468 
  8469 *** ZF ***
  8470 
  8471 * ZF: simplification automatically cancels common terms in arithmetic
  8472 expressions over nat and int;
  8473 
  8474 * ZF: new treatment of nat to minimize type-checking: all operators
  8475 coerce their operands to a natural number using the function natify,
  8476 making the algebraic laws unconditional;
  8477 
  8478 * ZF: as above, for int: operators coerce their operands to an integer
  8479 using the function intify;
  8480 
  8481 * ZF: the integer library now contains many of the usual laws for the
  8482 orderings, including $<=, and monotonicity laws for $+ and $*;
  8483 
  8484 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  8485 simplification;
  8486 
  8487 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  8488 to the simplifier and classical reasoner simultaneously;
  8489 
  8490 
  8491 *** General ***
  8492 
  8493 * Provers: blast_tac now handles actual object-logic rules as
  8494 assumptions; note that auto_tac uses blast_tac internally as well;
  8495 
  8496 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  8497 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  8498 
  8499 * Provers: delrules now handles destruct rules as well (no longer need
  8500 explicit make_elim);
  8501 
  8502 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  8503   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  8504 use instead the strong form,
  8505   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  8506 in HOL, FOL and ZF the function cla_make_elim will create such rules
  8507 from destruct-rules;
  8508 
  8509 * Provers: Simplifier.easy_setup provides a fast path to basic
  8510 Simplifier setup for new object-logics;
  8511 
  8512 * Pure: AST translation rules no longer require constant head on LHS;
  8513 
  8514 * Pure: improved name spaces: ambiguous output is qualified; support
  8515 for hiding of names;
  8516 
  8517 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  8518 XSYMBOL_HOME; no longer need to do manual configuration in most
  8519 situations;
  8520 
  8521 * system: compression of ML heaps images may now be controlled via -c
  8522 option of isabelle and isatool usedir (currently only observed by
  8523 Poly/ML);
  8524 
  8525 * system: isatool installfonts may handle X-Symbol fonts as well (very
  8526 useful for remote X11);
  8527 
  8528 * system: provide TAGS file for Isabelle sources;
  8529 
  8530 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  8531 order;
  8532 
  8533 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  8534 timing flag supersedes proof_timing and Toplevel.trace;
  8535 
  8536 * ML: new combinators |>> and |>>> for incremental transformations
  8537 with secondary results (e.g. certain theory extensions):
  8538 
  8539 * ML: PureThy.add_defs gets additional argument to indicate potential
  8540 overloading (usually false);
  8541 
  8542 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  8543 results;
  8544 
  8545 
  8546 
  8547 New in Isabelle99 (October 1999)
  8548 --------------------------------
  8549 
  8550 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8551 
  8552 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  8553 are no longer simplified.  (This allows the simplifier to unfold recursive
  8554 functional programs.)  To restore the old behaviour, declare
  8555 
  8556     Delcongs [if_weak_cong];
  8557 
  8558 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  8559 complement;
  8560 
  8561 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  8562 
  8563 * HOL/datatype: mutual_induct_tac no longer exists --
  8564   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  8565 
  8566 * HOL/typedef: fixed type inference for representing set; type
  8567 arguments now have to occur explicitly on the rhs as type constraints;
  8568 
  8569 * ZF: The con_defs part of an inductive definition may no longer refer
  8570 to constants declared in the same theory;
  8571 
  8572 * HOL, ZF: the function mk_cases, generated by the inductive
  8573 definition package, has lost an argument.  To simplify its result, it
  8574 uses the default simpset instead of a supplied list of theorems.
  8575 
  8576 * HOL/List: the constructors of type list are now Nil and Cons;
  8577 
  8578 * Simplifier: the type of the infix ML functions
  8579         setSSolver addSSolver setSolver addSolver
  8580 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  8581 for packaging solvers. A solver is created via
  8582         mk_solver: string -> (thm list -> int -> tactic) -> solver
  8583 where the string argument is only a comment.
  8584 
  8585 
  8586 *** Proof tools ***
  8587 
  8588 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  8589 decision procedure for linear arithmetic. Currently it is used for
  8590 types `nat', `int', and `real' in HOL (see below); it can, should and
  8591 will be instantiated for other types and logics as well.
  8592 
  8593 * The simplifier now accepts rewrite rules with flexible heads, eg
  8594      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  8595   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  8596   matching.
  8597 
  8598 
  8599 *** General ***
  8600 
  8601 * New Isabelle/Isar subsystem provides an alternative to traditional
  8602 tactical theorem proving; together with the ProofGeneral/isar user
  8603 interface it offers an interactive environment for developing human
  8604 readable proof documents (Isar == Intelligible semi-automated
  8605 reasoning); for further information see isatool doc isar-ref,
  8606 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  8607 
  8608 * improved and simplified presentation of theories: better HTML markup
  8609 (including colors), graph views in several sizes; isatool usedir now
  8610 provides a proper interface for user theories (via -P option); actual
  8611 document preparation based on (PDF)LaTeX is available as well (for
  8612 new-style theories only); see isatool doc system for more information;
  8613 
  8614 * native support for Proof General, both for classic Isabelle and
  8615 Isabelle/Isar;
  8616 
  8617 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  8618 using the graph browser tool;
  8619 
  8620 * Isabelle manuals now also available as PDF;
  8621 
  8622 * theory loader rewritten from scratch (may not be fully
  8623 bug-compatible); old loadpath variable has been replaced by show_path,
  8624 add_path, del_path, reset_path functions; new operations such as
  8625 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  8626 isatool doc ref);
  8627 
  8628 * improved isatool install: option -k creates KDE application icon,
  8629 option -p DIR installs standalone binaries;
  8630 
  8631 * added ML_PLATFORM setting (useful for cross-platform installations);
  8632 more robust handling of platform specific ML images for SML/NJ;
  8633 
  8634 * the settings environment is now statically scoped, i.e. it is never
  8635 created again in sub-processes invoked from isabelle, isatool, or
  8636 Isabelle;
  8637 
  8638 * path element specification '~~' refers to '$ISABELLE_HOME';
  8639 
  8640 * in locales, the "assumes" and "defines" parts may be omitted if
  8641 empty;
  8642 
  8643 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  8644 long arrows);
  8645 
  8646 * new print_mode "HTML";
  8647 
  8648 * new flag show_tags controls display of tags of theorems (which are
  8649 basically just comments that may be attached by some tools);
  8650 
  8651 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  8652 mode and goal output format:
  8653 
  8654 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  8655 244c244
  8656 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  8657 ---
  8658 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  8659 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  8660 181c181
  8661 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  8662 ---
  8663 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  8664 
  8665 * function bind_thms stores lists of theorems (cf. bind_thm);
  8666 
  8667 * new shorthand tactics ftac, eatac, datac, fatac;
  8668 
  8669 * qed (and friends) now accept "" as result name; in that case the
  8670 theorem is not stored, but proper checks and presentation of the
  8671 result still apply;
  8672 
  8673 * theorem database now also indexes constants "Trueprop", "all",
  8674 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  8675 
  8676 
  8677 *** HOL ***
  8678 
  8679 ** HOL arithmetic **
  8680 
  8681 * There are now decision procedures for linear arithmetic over nat and
  8682 int:
  8683 
  8684 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  8685 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  8686 are treated as atomic; subformulae not involving type `nat' or `int'
  8687 are ignored; quantified subformulae are ignored unless they are
  8688 positive universal or negative existential. The tactic has to be
  8689 invoked by hand and can be a little bit slow. In particular, the
  8690 running time is exponential in the number of occurrences of `min' and
  8691 `max', and `-' on `nat'.
  8692 
  8693 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  8694 (negated) (in)equalities among the premises and the conclusion into
  8695 account (i.e. no compound formulae) and does not know about `min' and
  8696 `max', and `-' on `nat'. It is fast and is used automatically by the
  8697 simplifier.
  8698 
  8699 NB: At the moment, these decision procedures do not cope with mixed
  8700 nat/int formulae where the two parts interact, such as `m < n ==>
  8701 int(m) < int(n)'.
  8702 
  8703 * HOL/Numeral provides a generic theory of numerals (encoded
  8704 efficiently as bit strings); setup for types nat/int/real is in place;
  8705 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  8706 int, existing theories and proof scripts may require a few additional
  8707 type constraints;
  8708 
  8709 * integer division and remainder can now be performed on constant
  8710 arguments;
  8711 
  8712 * many properties of integer multiplication, division and remainder
  8713 are now available;
  8714 
  8715 * An interface to the Stanford Validity Checker (SVC) is available through the
  8716 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  8717 are proved automatically.  SVC must be installed separately, and its results
  8718 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  8719 invocation of the underlying oracle).  For SVC see
  8720   http://verify.stanford.edu/SVC
  8721 
  8722 * IsaMakefile: the HOL-Real target now builds an actual image;
  8723 
  8724 
  8725 ** HOL misc **
  8726 
  8727 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  8728 (in Isabelle/Isar) -- by Gertrud Bauer;
  8729 
  8730 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  8731 analysis for assembly languages with subtypes;
  8732 
  8733 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  8734 -- avoids syntactic ambiguities and treats state, transition, and
  8735 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  8736 changed syntax and (many) tactics;
  8737 
  8738 * HOL/inductive: Now also handles more general introduction rules such
  8739   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  8740   theorems are now maintained within the theory (maintained via the
  8741   "mono" attribute);
  8742 
  8743 * HOL/datatype: Now also handles arbitrarily branching datatypes
  8744   (using function types) such as
  8745 
  8746   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  8747 
  8748 * HOL/record: record_simproc (part of the default simpset) takes care
  8749 of selectors applied to updated records; record_split_tac is no longer
  8750 part of the default claset; update_defs may now be removed from the
  8751 simpset in many cases; COMPATIBILITY: old behavior achieved by
  8752 
  8753   claset_ref () := claset() addSWrapper record_split_wrapper;
  8754   Delsimprocs [record_simproc]
  8755 
  8756 * HOL/typedef: fixed type inference for representing set; type
  8757 arguments now have to occur explicitly on the rhs as type constraints;
  8758 
  8759 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  8760 names rather than an ML expression;
  8761 
  8762 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  8763 supplied later.  Program schemes can be defined, such as
  8764     "While B C s = (if B s then While B C (C s) else s)"
  8765 where the well-founded relation can be chosen after B and C have been given.
  8766 
  8767 * HOL/List: the constructors of type list are now Nil and Cons;
  8768 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  8769 course, ML tools referring to List.list.op # etc. have to be adapted;
  8770 
  8771 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  8772 disabled by default; run isabelle with option -m HOL to get back to
  8773 the original Gordon/HOL-style output;
  8774 
  8775 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  8776 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  8777 
  8778 * HOL basic syntax simplified (more orthogonal): all variants of
  8779 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  8780 Eps operator is provided as well: "SOME x. P[x]";
  8781 
  8782 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  8783 
  8784 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  8785 thus available for user theories;
  8786 
  8787 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  8788 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  8789 time;
  8790 
  8791 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  8792 several times and then mp;
  8793 
  8794 
  8795 *** LK ***
  8796 
  8797 * the notation <<...>> is now available as a notation for sequences of
  8798 formulas;
  8799 
  8800 * the simplifier is now installed
  8801 
  8802 * the axiom system has been generalized (thanks to Soren Heilmann)
  8803 
  8804 * the classical reasoner now has a default rule database
  8805 
  8806 
  8807 *** ZF ***
  8808 
  8809 * new primrec section allows primitive recursive functions to be given
  8810 directly (as in HOL) over datatypes and the natural numbers;
  8811 
  8812 * new tactics induct_tac and exhaust_tac for induction (or case
  8813 analysis) over datatypes and the natural numbers;
  8814 
  8815 * the datatype declaration of type T now defines the recursor T_rec;
  8816 
  8817 * simplification automatically does freeness reasoning for datatype
  8818 constructors;
  8819 
  8820 * automatic type-inference, with AddTCs command to insert new
  8821 type-checking rules;
  8822 
  8823 * datatype introduction rules are now added as Safe Introduction rules
  8824 to the claset;
  8825 
  8826 * the syntax "if P then x else y" is now available in addition to
  8827 if(P,x,y);
  8828 
  8829 
  8830 *** Internal programming interfaces ***
  8831 
  8832 * tuned simplifier trace output; new flag debug_simp;
  8833 
  8834 * structures Vartab / Termtab (instances of TableFun) offer efficient
  8835 tables indexed by indexname_ord / term_ord (compatible with aconv);
  8836 
  8837 * AxClass.axclass_tac lost the theory argument;
  8838 
  8839 * tuned current_goals_markers semantics: begin / end goal avoids
  8840 printing empty lines;
  8841 
  8842 * removed prs and prs_fn hook, which was broken because it did not
  8843 include \n in its semantics, forcing writeln to add one
  8844 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  8845 string -> unit if you really want to output text without newline;
  8846 
  8847 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  8848 plain output, interface builders may have to enable 'isabelle_font'
  8849 mode to get Isabelle font glyphs as before;
  8850 
  8851 * refined token_translation interface; INCOMPATIBILITY: output length
  8852 now of type real instead of int;
  8853 
  8854 * theory loader actions may be traced via new ThyInfo.add_hook
  8855 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8856 your own database of information attached to *whole* theories -- as
  8857 opposed to intra-theory data slots offered via TheoryDataFun;
  8858 
  8859 * proper handling of dangling sort hypotheses (at last!);
  8860 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8861 extra sort hypotheses that can be witnessed from the type signature;
  8862 the force_strip_shyps flag is gone, any remaining shyps are simply
  8863 left in the theorem (with a warning issued by strip_shyps_warning);
  8864 
  8865 
  8866 
  8867 New in Isabelle98-1 (October 1998)
  8868 ----------------------------------
  8869 
  8870 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8871 
  8872 * several changes of automated proof tools;
  8873 
  8874 * HOL: major changes to the inductive and datatype packages, including
  8875 some minor incompatibilities of theory syntax;
  8876 
  8877 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8878 called `inj_on';
  8879 
  8880 * HOL: removed duplicate thms in Arith:
  8881   less_imp_add_less  should be replaced by  trans_less_add1
  8882   le_imp_add_le      should be replaced by  trans_le_add1
  8883 
  8884 * HOL: unary minus is now overloaded (new type constraints may be
  8885 required);
  8886 
  8887 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8888 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8889 now taken as an integer constant.
  8890 
  8891 * Pure: ML function 'theory_of' renamed to 'theory';
  8892 
  8893 
  8894 *** Proof tools ***
  8895 
  8896 * Simplifier:
  8897   1. Asm_full_simp_tac is now more aggressive.
  8898      1. It will sometimes reorient premises if that increases their power to
  8899         simplify.
  8900      2. It does no longer proceed strictly from left to right but may also
  8901         rotate premises to achieve further simplification.
  8902      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8903      old Asm_full_simp_tac in that it does not rotate premises.
  8904   2. The simplifier now knows a little bit about nat-arithmetic.
  8905 
  8906 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8907 allows for selected deletion of wrappers, by introduction of names for
  8908 wrapper functionals.  This implies that addbefore, addSbefore,
  8909 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8910 and that adding two tactics with the same name overwrites the first
  8911 one (emitting a warning).
  8912   type wrapper = (int -> tactic) -> (int -> tactic)
  8913   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8914   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8915   delWrapper, delSWrapper: claset *  string            -> claset
  8916   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8917 
  8918 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8919 semantics; addbefore now affects only the unsafe part of step_tac
  8920 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8921 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8922 by Force_tac;
  8923 
  8924 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8925 compWrapper; added safe wrapper (and access functions for it);
  8926 
  8927 * HOL/split_all_tac is now much faster and fails if there is nothing
  8928 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8929 and the names of the automatically generated variables have changed.
  8930 split_all_tac has moved within claset() from unsafe wrappers to safe
  8931 wrappers, which means that !!-bound variables are split much more
  8932 aggressively, and safe_tac and clarify_tac now split such variables.
  8933 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8934 Note: the same holds for record_split_tac, which does the job of
  8935 split_all_tac for record fields.
  8936 
  8937 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8938 permanently to the default simpset using Addsplits just like
  8939 Addsimps. They can be removed via Delsplits just like
  8940 Delsimps. Lower-case versions are also available.
  8941 
  8942 * HOL/Simplifier: The rule split_if is now part of the default
  8943 simpset. This means that the simplifier will eliminate all occurrences
  8944 of if-then-else in the conclusion of a goal. To prevent this, you can
  8945 either remove split_if completely from the default simpset by
  8946 `Delsplits [split_if]' or remove it in a specific call of the
  8947 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8948 other case splitting rules to/from the default simpset: every datatype
  8949 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8950 t is the name of the datatype).
  8951 
  8952 * Classical reasoner / Simplifier combination: new force_tac (and
  8953 derivatives Force_tac, force) combines rewriting and classical
  8954 reasoning (and whatever other tools) similarly to auto_tac, but is
  8955 aimed to solve the given subgoal completely.
  8956 
  8957 
  8958 *** General ***
  8959 
  8960 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8961 and `goalw': the theory is no longer needed as an explicit argument -
  8962 the current theory context is used; assumptions are no longer returned
  8963 at the ML-level unless one of them starts with ==> or !!; it is
  8964 recommended to convert to these new commands using isatool fixgoal
  8965 (backup your sources first!);
  8966 
  8967 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8968 the current theory context, and 'theory' to lookup stored theories;
  8969 
  8970 * new theory section 'locale' for declaring constants, assumptions and
  8971 definitions that have local scope;
  8972 
  8973 * new theory section 'nonterminals' for purely syntactic types;
  8974 
  8975 * new theory section 'setup' for generic ML setup functions
  8976 (e.g. package initialization);
  8977 
  8978 * the distribution now includes Isabelle icons: see
  8979 lib/logo/isabelle-{small,tiny}.xpm;
  8980 
  8981 * isatool install - install binaries with absolute references to
  8982 ISABELLE_HOME/bin;
  8983 
  8984 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8985 
  8986 * print mode 'emacs' reserved for Isamode;
  8987 
  8988 * support multiple print (ast) translations per constant name;
  8989 
  8990 * theorems involving oracles are now printed with a suffixed [!];
  8991 
  8992 
  8993 *** HOL ***
  8994 
  8995 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8996 
  8997 * HOL/inductive package reorganized and improved: now supports mutual
  8998 definitions such as
  8999 
  9000   inductive EVEN ODD
  9001     intrs
  9002       null "0 : EVEN"
  9003       oddI "n : EVEN ==> Suc n : ODD"
  9004       evenI "n : ODD ==> Suc n : EVEN"
  9005 
  9006 new theorem list "elims" contains an elimination rule for each of the
  9007 recursive sets; inductive definitions now handle disjunctive premises
  9008 correctly (also ZF);
  9009 
  9010 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  9011 "mutual_induct" no longer exists - the induction rule is always
  9012 contained in "induct";
  9013 
  9014 
  9015 * HOL/datatype package re-implemented and greatly improved: now
  9016 supports mutually recursive datatypes such as
  9017 
  9018   datatype
  9019     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  9020             | SUM ('a aexp) ('a aexp)
  9021             | DIFF ('a aexp) ('a aexp)
  9022             | NUM 'a
  9023   and
  9024     'a bexp = LESS ('a aexp) ('a aexp)
  9025             | AND ('a bexp) ('a bexp)
  9026             | OR ('a bexp) ('a bexp)
  9027 
  9028 as well as indirectly recursive datatypes such as
  9029 
  9030   datatype
  9031     ('a, 'b) term = Var 'a
  9032                   | App 'b ((('a, 'b) term) list)
  9033 
  9034 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  9035 induction on mutually / indirectly recursive datatypes.
  9036 
  9037 Primrec equations are now stored in theory and can be accessed via
  9038 <function_name>.simps.
  9039 
  9040 INCOMPATIBILITIES:
  9041 
  9042   - Theories using datatypes must now have theory Datatype as an
  9043     ancestor.
  9044   - The specific <typename>.induct_tac no longer exists - use the
  9045     generic induct_tac instead.
  9046   - natE has been renamed to nat.exhaust - use exhaust_tac
  9047     instead of res_inst_tac ... natE. Note that the variable
  9048     names in nat.exhaust differ from the names in natE, this
  9049     may cause some "fragile" proofs to fail.
  9050   - The theorems split_<typename>_case and split_<typename>_case_asm
  9051     have been renamed to <typename>.split and <typename>.split_asm.
  9052   - Since default sorts of type variables are now handled correctly,
  9053     some datatype definitions may have to be annotated with explicit
  9054     sort constraints.
  9055   - Primrec definitions no longer require function name and type
  9056     of recursive argument.
  9057 
  9058 Consider using isatool fixdatatype to adapt your theories and proof
  9059 scripts to the new package (backup your sources first!).
  9060 
  9061 
  9062 * HOL/record package: considerably improved implementation; now
  9063 includes concrete syntax for record types, terms, updates; theorems
  9064 for surjective pairing and splitting !!-bound record variables; proof
  9065 support is as follows:
  9066 
  9067   1) standard conversions (selectors or updates applied to record
  9068 constructor terms) are part of the standard simpset;
  9069 
  9070   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  9071 made part of standard simpset and claset via addIffs;
  9072 
  9073   3) a tactic for record field splitting (record_split_tac) is part of
  9074 the standard claset (addSWrapper);
  9075 
  9076 To get a better idea about these rules you may retrieve them via
  9077 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  9078 the name of your record type.
  9079 
  9080 The split tactic 3) conceptually simplifies by the following rule:
  9081 
  9082   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  9083 
  9084 Thus any record variable that is bound by meta-all will automatically
  9085 blow up into some record constructor term, consequently the
  9086 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  9087 solve record problems automatically.
  9088 
  9089 
  9090 * reorganized the main HOL image: HOL/Integ and String loaded by
  9091 default; theory Main includes everything;
  9092 
  9093 * automatic simplification of integer sums and comparisons, using cancellation;
  9094 
  9095 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  9096 
  9097 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  9098 
  9099 * many new identities for unions, intersections, set difference, etc.;
  9100 
  9101 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  9102 called split_if, split_split, split_sum_case and split_nat_case (to go
  9103 with add/delsplits);
  9104 
  9105 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  9106 (?x::unit) = (); this is made part of the default simpset, which COULD
  9107 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  9108 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  9109 unit_abs_eta_conv is added in order to counter the effect of
  9110 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  9111 %u.f();
  9112 
  9113 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  9114 makes more sense);
  9115 
  9116 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  9117   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  9118   disjointness reasoning but breaking a few old proofs.
  9119 
  9120 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  9121 to 'converse' from 'inverse' (for compatibility with ZF and some
  9122 literature);
  9123 
  9124 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  9125 the well-founded relation;
  9126 
  9127 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  9128     Compl A.  The "Compl" syntax remains available as input syntax for this
  9129     release ONLY.
  9130 
  9131 * HOL/Update: new theory of function updates:
  9132     f(a:=b) == %x. if x=a then b else f x
  9133 may also be iterated as in f(a:=b,c:=d,...);
  9134 
  9135 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  9136 
  9137 * HOL/List:
  9138   - new function list_update written xs[i:=v] that updates the i-th
  9139     list position. May also be iterated as in xs[i:=a,j:=b,...].
  9140   - new function `upt' written [i..j(] which generates the list
  9141     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  9142     bound write [i..j], which is a shorthand for [i..j+1(].
  9143   - new lexicographic orderings and corresponding wellfoundedness theorems.
  9144 
  9145 * HOL/Arith:
  9146   - removed 'pred' (predecessor) function;
  9147   - generalized some theorems about n-1;
  9148   - many new laws about "div" and "mod";
  9149   - new laws about greatest common divisors (see theory ex/Primes);
  9150 
  9151 * HOL/Relation: renamed the relational operator r^-1 "converse"
  9152 instead of "inverse";
  9153 
  9154 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  9155   of the multiset ordering;
  9156 
  9157 * directory HOL/Real: a construction of the reals using Dedekind cuts
  9158   (not included by default);
  9159 
  9160 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  9161 
  9162 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  9163   programs, i.e. different program variables may have different types.
  9164 
  9165 * calling (stac rew i) now fails if "rew" has no effect on the goal
  9166   [previously, this check worked only if the rewrite rule was unconditional]
  9167   Now rew can involve either definitions or equalities (either == or =).
  9168 
  9169 
  9170 *** ZF ***
  9171 
  9172 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  9173   only the theorems proved on ZF.ML;
  9174 
  9175 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  9176   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  9177   disjointness reasoning but breaking a few old proofs.
  9178 
  9179 * ZF/Update: new theory of function updates
  9180     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  9181   may also be iterated as in f(a:=b,c:=d,...);
  9182 
  9183 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  9184 
  9185 * calling (stac rew i) now fails if "rew" has no effect on the goal
  9186   [previously, this check worked only if the rewrite rule was unconditional]
  9187   Now rew can involve either definitions or equalities (either == or =).
  9188 
  9189 * case_tac provided for compatibility with HOL
  9190     (like the old excluded_middle_tac, but with subgoals swapped)
  9191 
  9192 
  9193 *** Internal programming interfaces ***
  9194 
  9195 * Pure: several new basic modules made available for general use, see
  9196 also src/Pure/README;
  9197 
  9198 * improved the theory data mechanism to support encapsulation (data
  9199 kind name replaced by private Object.kind, acting as authorization
  9200 key); new type-safe user interface via functor TheoryDataFun; generic
  9201 print_data function becomes basically useless;
  9202 
  9203 * removed global_names compatibility flag -- all theory declarations
  9204 are qualified by default;
  9205 
  9206 * module Pure/Syntax now offers quote / antiquote translation
  9207 functions (useful for Hoare logic etc. with implicit dependencies);
  9208 see HOL/ex/Antiquote for an example use;
  9209 
  9210 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  9211 cterm -> thm;
  9212 
  9213 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  9214 subgoal;
  9215 
  9216 * Display.print_goals function moved to Locale.print_goals;
  9217 
  9218 * standard print function for goals supports current_goals_markers
  9219 variable for marking begin of proof, end of proof, start of goal; the
  9220 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  9221 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  9222 for example;
  9223 
  9224 
  9225 
  9226 New in Isabelle98 (January 1998)
  9227 --------------------------------
  9228 
  9229 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  9230 
  9231 * changed lexical syntax of terms / types: dots made part of long
  9232 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  9233 
  9234 * simpset (and claset) reference variable replaced by functions
  9235 simpset / simpset_ref;
  9236 
  9237 * no longer supports theory aliases (via merge) and non-trivial
  9238 implicit merge of thms' signatures;
  9239 
  9240 * most internal names of constants changed due to qualified names;
  9241 
  9242 * changed Pure/Sequence interface (see Pure/seq.ML);
  9243 
  9244 
  9245 *** General Changes ***
  9246 
  9247 * hierachically structured name spaces (for consts, types, axms, thms
  9248 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  9249 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  9250 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  9251 long_names for fully qualified output names; NOTE: ML programs
  9252 (special tactics, packages etc.) referring to internal names may have
  9253 to be adapted to cope with fully qualified names; in case of severe
  9254 backward campatibility problems try setting 'global_names' at compile
  9255 time to have enrything declared within a flat name space; one may also
  9256 fine tune name declarations in theories via the 'global' and 'local'
  9257 section;
  9258 
  9259 * reimplemented the implicit simpset and claset using the new anytype
  9260 data filed in signatures; references simpset:simpset ref etc. are
  9261 replaced by functions simpset:unit->simpset and
  9262 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  9263 to patch your ML files accordingly;
  9264 
  9265 * HTML output now includes theory graph data for display with Java
  9266 applet or isatool browser; data generated automatically via isatool
  9267 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  9268 
  9269 * defs may now be conditional; improved rewrite_goals_tac to handle
  9270 conditional equations;
  9271 
  9272 * defs now admits additional type arguments, using TYPE('a) syntax;
  9273 
  9274 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  9275 creates a new theory node; implicit merge of thms' signatures is
  9276 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  9277 transfer:theory->thm->thm in (rare) cases;
  9278 
  9279 * improved handling of draft signatures / theories; draft thms (and
  9280 ctyps, cterms) are automatically promoted to real ones;
  9281 
  9282 * slightly changed interfaces for oracles: admit many per theory, named
  9283 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  9284 
  9285 * print_goals: optional output of const types (set show_consts and
  9286 show_types);
  9287 
  9288 * improved output of warnings (###) and errors (***);
  9289 
  9290 * subgoal_tac displays a warning if the new subgoal has type variables;
  9291 
  9292 * removed old README and Makefiles;
  9293 
  9294 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  9295 
  9296 * removed obsolete init_pps and init_database;
  9297 
  9298 * deleted the obsolete tactical STATE, which was declared by
  9299     fun STATE tacfun st = tacfun st st;
  9300 
  9301 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  9302 (which abbreviates $HOME);
  9303 
  9304 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  9305 use isatool fixseq to adapt your ML programs (this works for fully
  9306 qualified references to the Sequence structure only!);
  9307 
  9308 * use_thy no longer requires writable current directory; it always
  9309 reloads .ML *and* .thy file, if either one is out of date;
  9310 
  9311 
  9312 *** Classical Reasoner ***
  9313 
  9314 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  9315 tactics that use classical reasoning to simplify a subgoal without
  9316 splitting it into several subgoals;
  9317 
  9318 * Safe_tac: like safe_tac but uses the default claset;
  9319 
  9320 
  9321 *** Simplifier ***
  9322 
  9323 * added simplification meta rules:
  9324     (asm_)(full_)simplify: simpset -> thm -> thm;
  9325 
  9326 * simplifier.ML no longer part of Pure -- has to be loaded by object
  9327 logics (again);
  9328 
  9329 * added prems argument to simplification procedures;
  9330 
  9331 * HOL, FOL, ZF: added infix function `addsplits':
  9332   instead of `<simpset> setloop (split_tac <thms>)'
  9333   you can simply write `<simpset> addsplits <thms>'
  9334 
  9335 
  9336 *** Syntax ***
  9337 
  9338 * TYPE('a) syntax for type reflection terms;
  9339 
  9340 * no longer handles consts with name "" -- declare as 'syntax' instead;
  9341 
  9342 * pretty printer: changed order of mixfix annotation preference (again!);
  9343 
  9344 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  9345 
  9346 
  9347 *** HOL ***
  9348 
  9349 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  9350   with `addloop' of the simplifier to faciliate case splitting in premises.
  9351 
  9352 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  9353 
  9354 * HOL/Auth: new protocol proofs including some for the Internet
  9355   protocol TLS;
  9356 
  9357 * HOL/Map: new theory of `maps' a la VDM;
  9358 
  9359 * HOL/simplifier: simplification procedures nat_cancel_sums for
  9360 cancelling out common nat summands from =, <, <= (in)equalities, or
  9361 differences; simplification procedures nat_cancel_factor for
  9362 cancelling common factor from =, <, <= (in)equalities over natural
  9363 sums; nat_cancel contains both kinds of procedures, it is installed by
  9364 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  9365 
  9366 * HOL/simplifier: terms of the form
  9367   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  9368   are rewritten to
  9369   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  9370   and those of the form
  9371   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  9372   are rewritten to
  9373   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  9374 
  9375 * HOL/datatype
  9376   Each datatype `t' now comes with a theorem `split_t_case' of the form
  9377 
  9378   P(t_case f1 ... fn x) =
  9379      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  9380         ...
  9381        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  9382      )
  9383 
  9384   and a theorem `split_t_case_asm' of the form
  9385 
  9386   P(t_case f1 ... fn x) =
  9387     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  9388         ...
  9389        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  9390      )
  9391   which can be added to a simpset via `addsplits'. The existing theorems
  9392   expand_list_case and expand_option_case have been renamed to
  9393   split_list_case and split_option_case.
  9394 
  9395 * HOL/Arithmetic:
  9396   - `pred n' is automatically converted to `n-1'.
  9397     Users are strongly encouraged not to use `pred' any longer,
  9398     because it will disappear altogether at some point.
  9399   - Users are strongly encouraged to write "0 < n" rather than
  9400     "n ~= 0". Theorems and proof tools have been modified towards this
  9401     `standard'.
  9402 
  9403 * HOL/Lists:
  9404   the function "set_of_list" has been renamed "set" (and its theorems too);
  9405   the function "nth" now takes its arguments in the reverse order and
  9406   has acquired the infix notation "!" as in "xs!n".
  9407 
  9408 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  9409 
  9410 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  9411   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  9412 
  9413 * HOL/record: extensible records with schematic structural subtyping
  9414 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  9415 still lacks various theorems and concrete record syntax;
  9416 
  9417 
  9418 *** HOLCF ***
  9419 
  9420 * removed "axioms" and "generated by" sections;
  9421 
  9422 * replaced "ops" section by extended "consts" section, which is capable of
  9423   handling the continuous function space "->" directly;
  9424 
  9425 * domain package:
  9426   . proves theorems immediately and stores them in the theory,
  9427   . creates hierachical name space,
  9428   . now uses normal mixfix annotations (instead of cinfix...),
  9429   . minor changes to some names and values (for consistency),
  9430   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  9431   . separator between mutual domain defs: changed "," to "and",
  9432   . improved handling of sort constraints;  now they have to
  9433     appear on the left-hand side of the equations only;
  9434 
  9435 * fixed LAM <x,y,zs>.b syntax;
  9436 
  9437 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  9438 adm (%x. P (t x)), where P is chainfinite and t continuous;
  9439 
  9440 
  9441 *** FOL and ZF ***
  9442 
  9443 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  9444   with `addloop' of the simplifier to faciliate case splitting in premises.
  9445 
  9446 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  9447 in HOL, they strip ALL and --> from proved theorems;
  9448 
  9449 
  9450 
  9451 New in Isabelle94-8 (May 1997)
  9452 ------------------------------
  9453 
  9454 *** General Changes ***
  9455 
  9456 * new utilities to build / run / maintain Isabelle etc. (in parts
  9457 still somewhat experimental); old Makefiles etc. still functional;
  9458 
  9459 * new 'Isabelle System Manual';
  9460 
  9461 * INSTALL text, together with ./configure and ./build scripts;
  9462 
  9463 * reimplemented type inference for greater efficiency, better error
  9464 messages and clean internal interface;
  9465 
  9466 * prlim command for dealing with lots of subgoals (an easier way of
  9467 setting goals_limit);
  9468 
  9469 
  9470 *** Syntax ***
  9471 
  9472 * supports alternative (named) syntax tables (parser and pretty
  9473 printer); internal interface is provided by add_modesyntax(_i);
  9474 
  9475 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  9476 be used in conjunction with the Isabelle symbol font; uses the
  9477 "symbols" syntax table;
  9478 
  9479 * added token_translation interface (may translate name tokens in
  9480 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  9481 the current print_mode); IMPORTANT: user print translation functions
  9482 are responsible for marking newly introduced bounds
  9483 (Syntax.mark_boundT);
  9484 
  9485 * token translations for modes "xterm" and "xterm_color" that display
  9486 names in bold, underline etc. or colors (which requires a color
  9487 version of xterm);
  9488 
  9489 * infixes may now be declared with names independent of their syntax;
  9490 
  9491 * added typed_print_translation (like print_translation, but may
  9492 access type of constant);
  9493 
  9494 
  9495 *** Classical Reasoner ***
  9496 
  9497 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  9498 some limitations.  Blast_tac...
  9499   + ignores addss, addbefore, addafter; this restriction is intrinsic
  9500   + ignores elimination rules that don't have the correct format
  9501         (the conclusion MUST be a formula variable)
  9502   + ignores types, which can make HOL proofs fail
  9503   + rules must not require higher-order unification, e.g. apply_type in ZF
  9504     [message "Function Var's argument not a bound variable" relates to this]
  9505   + its proof strategy is more general but can actually be slower
  9506 
  9507 * substitution with equality assumptions no longer permutes other
  9508 assumptions;
  9509 
  9510 * minor changes in semantics of addafter (now called addaltern); renamed
  9511 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  9512 (and access functions for it);
  9513 
  9514 * improved combination of classical reasoner and simplifier:
  9515   + functions for handling clasimpsets
  9516   + improvement of addss: now the simplifier is called _after_ the
  9517     safe steps.
  9518   + safe variant of addss called addSss: uses safe simplifications
  9519     _during_ the safe steps. It is more complete as it allows multiple
  9520     instantiations of unknowns (e.g. with slow_tac).
  9521 
  9522 *** Simplifier ***
  9523 
  9524 * added interface for simplification procedures (functions that
  9525 produce *proven* rewrite rules on the fly, depending on current
  9526 redex);
  9527 
  9528 * ordering on terms as parameter (used for ordered rewriting);
  9529 
  9530 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  9531 
  9532 * the solver is now split into a safe and an unsafe part.
  9533 This should be invisible for the normal user, except that the
  9534 functions setsolver and addsolver have been renamed to setSolver and
  9535 addSolver; added safe_asm_full_simp_tac;
  9536 
  9537 
  9538 *** HOL ***
  9539 
  9540 * a generic induction tactic `induct_tac' which works for all datatypes and
  9541 also for type `nat';
  9542 
  9543 * a generic case distinction tactic `exhaust_tac' which works for all
  9544 datatypes and also for type `nat';
  9545 
  9546 * each datatype comes with a function `size';
  9547 
  9548 * patterns in case expressions allow tuple patterns as arguments to
  9549 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  9550 
  9551 * primrec now also works with type nat;
  9552 
  9553 * recdef: a new declaration form, allows general recursive functions to be
  9554 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  9555 
  9556 * the constant for negation has been renamed from "not" to "Not" to
  9557 harmonize with FOL, ZF, LK, etc.;
  9558 
  9559 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  9560 infinite lists;
  9561 
  9562 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  9563 
  9564 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  9565 problems in commutative rings, using axiomatic type classes for + and *;
  9566 
  9567 * more examples in HOL/MiniML and HOL/Auth;
  9568 
  9569 * more default rewrite rules for quantifiers, union/intersection;
  9570 
  9571 * a new constant `arbitrary == @x.False';
  9572 
  9573 * HOLCF/IOA replaces old HOL/IOA;
  9574 
  9575 * HOLCF changes: derived all rules and arities
  9576   + axiomatic type classes instead of classes
  9577   + typedef instead of faking type definitions
  9578   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  9579   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  9580   + eliminated the types void, one, tr
  9581   + use unit lift and bool lift (with translations) instead of one and tr
  9582   + eliminated blift from Lift3.thy (use Def instead of blift)
  9583   all eliminated rules are derived as theorems --> no visible changes ;
  9584 
  9585 
  9586 *** ZF ***
  9587 
  9588 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  9589 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  9590 as ZF_cs addSIs [equalityI];
  9591 
  9592 
  9593 
  9594 New in Isabelle94-7 (November 96)
  9595 ---------------------------------
  9596 
  9597 * allowing negative levels (as offsets) in prlev and choplev;
  9598 
  9599 * super-linear speedup for large simplifications;
  9600 
  9601 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  9602 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  9603 FAIL); can suppress it using the command Delsimps (ex_simps @
  9604 all_simps); De Morgan laws are also now included, by default;
  9605 
  9606 * improved printing of ==>  :  ~:
  9607 
  9608 * new object-logic "Sequents" adds linear logic, while replacing LK
  9609 and Modal (thanks to Sara Kalvala);
  9610 
  9611 * HOL/Auth: correctness proofs for authentication protocols;
  9612 
  9613 * HOL: new auto_tac combines rewriting and classical reasoning (many
  9614 examples on HOL/Auth);
  9615 
  9616 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  9617 the rewriter and classical reasoner simultaneously;
  9618 
  9619 * function uresult no longer returns theorems in "standard" format;
  9620 regain previous version by: val uresult = standard o uresult;
  9621 
  9622 
  9623 
  9624 New in Isabelle94-6
  9625 -------------------
  9626 
  9627 * oracles -- these establish an interface between Isabelle and trusted
  9628 external reasoners, which may deliver results as theorems;
  9629 
  9630 * proof objects (in particular record all uses of oracles);
  9631 
  9632 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  9633 
  9634 * "constdefs" section in theory files;
  9635 
  9636 * "primrec" section (HOL) no longer requires names;
  9637 
  9638 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  9639 
  9640 
  9641 
  9642 New in Isabelle94-5
  9643 -------------------
  9644 
  9645 * reduced space requirements;
  9646 
  9647 * automatic HTML generation from theories;
  9648 
  9649 * theory files no longer require "..." (quotes) around most types;
  9650 
  9651 * new examples, including two proofs of the Church-Rosser theorem;
  9652 
  9653 * non-curried (1994) version of HOL is no longer distributed;
  9654 
  9655 
  9656 
  9657 New in Isabelle94-4
  9658 -------------------
  9659 
  9660 * greatly reduced space requirements;
  9661 
  9662 * theory files (.thy) no longer require \...\ escapes at line breaks;
  9663 
  9664 * searchable theorem database (see the section "Retrieving theorems" on
  9665 page 8 of the Reference Manual);
  9666 
  9667 * new examples, including Grabczewski's monumental case study of the
  9668 Axiom of Choice;
  9669 
  9670 * The previous version of HOL renamed to Old_HOL;
  9671 
  9672 * The new version of HOL (previously called CHOL) uses a curried syntax
  9673 for functions.  Application looks like f a b instead of f(a,b);
  9674 
  9675 * Mutually recursive inductive definitions finally work in HOL;
  9676 
  9677 * In ZF, pattern-matching on tuples is now available in all abstractions and
  9678 translates to the operator "split";
  9679 
  9680 
  9681 
  9682 New in Isabelle94-3
  9683 -------------------
  9684 
  9685 * new infix operator, addss, allowing the classical reasoner to
  9686 perform simplification at each step of its search.  Example:
  9687         fast_tac (cs addss ss)
  9688 
  9689 * a new logic, CHOL, the same as HOL, but with a curried syntax
  9690 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  9691 look like (a,b) instead of <a,b>;
  9692 
  9693 * PLEASE NOTE: CHOL will eventually replace HOL!
  9694 
  9695 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  9696 It translates to the operator "split".  A new theory of integers is available;
  9697 
  9698 * In ZF, integer numerals now denote two's-complement binary integers.
  9699 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  9700 
  9701 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  9702 of the Axiom of Choice;
  9703 
  9704 
  9705 
  9706 New in Isabelle94-2
  9707 -------------------
  9708 
  9709 * Significantly faster resolution;
  9710 
  9711 * the different sections in a .thy file can now be mixed and repeated
  9712 freely;
  9713 
  9714 * Database of theorems for FOL, HOL and ZF.  New
  9715 commands including qed, qed_goal and bind_thm store theorems in the database.
  9716 
  9717 * Simple database queries: return a named theorem (get_thm) or all theorems of
  9718 a given theory (thms_of), or find out what theory a theorem was proved in
  9719 (theory_of_thm);
  9720 
  9721 * Bugs fixed in the inductive definition and datatype packages;
  9722 
  9723 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  9724 and HOL_dup_cs obsolete;
  9725 
  9726 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  9727 have been removed;
  9728 
  9729 * Simpler definition of function space in ZF;
  9730 
  9731 * new results about cardinal and ordinal arithmetic in ZF;
  9732 
  9733 * 'subtype' facility in HOL for introducing new types as subsets of existing
  9734 types;
  9735 
  9736 :mode=text:wrap=hard:maxLineLen=72: