NEWS
author wenzelm
Fri, 27 Apr 2012 21:13:55 +0200
changeset 48678 befe55c8bbdc
parent 48677 7e009f4e9f47
child 48680 4d8cbea248b0
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
   490 a subset of the real numbers.  All operations are defined using the
   491 lifing-framework and proofs use the transfer method.  INCOMPATIBILITY.
   492 
   493   Changed Operations:
   494   float_abs -> abs
   495   float_nprt -> nprt
   496   float_pprt -> pprt
   497   pow2 -> use powr
   498   round_down -> float_round_down
   499   round_up -> float_round_up
   500   scale -> exponent
   501 
   502   Removed Operations:
   503   ceiling_fl, lb_mult, lb_mod, ub_mult, ub_mod
   504 
   505   Renamed Lemmas:
   506   abs_float_def -> Float.compute_float_abs
   507   bitlen_ge0 -> bitlen_nonneg
   508   bitlen.simps -> Float.compute_bitlen
   509   float_components -> Float_mantissa_exponent
   510   float_divl.simps -> Float.compute_float_divl
   511   float_divr.simps -> Float.compute_float_divr
   512   float_eq_odd -> mult_powr_eq_mult_powr_iff
   513   float_power -> real_of_float_power
   514   lapprox_posrat_def -> Float.compute_lapprox_posrat
   515   lapprox_rat.simps -> Float.compute_lapprox_rat
   516   le_float_def' -> Float.compute_float_le
   517   le_float_def -> less_eq_float.rep_eq
   518   less_float_def' -> Float.compute_float_less
   519   less_float_def -> less_float.rep_eq
   520   normfloat_def -> Float.compute_normfloat
   521   normfloat_imp_odd_or_zero -> mantissa_not_dvd and mantissa_noteq_0
   522   normfloat -> normfloat_def
   523   normfloat_unique -> use normfloat_def
   524   number_of_float_Float -> Float.compute_float_numeral, Float.compute_float_neg_numeral
   525   one_float_def -> Float.compute_float_one
   526   plus_float_def -> Float.compute_float_plus
   527   rapprox_posrat_def -> Float.compute_rapprox_posrat
   528   rapprox_rat.simps -> Float.compute_rapprox_rat
   529   real_of_float_0 -> zero_float.rep_eq
   530   real_of_float_1 -> one_float.rep_eq
   531   real_of_float_abs -> abs_float.rep_eq
   532   real_of_float_add -> plus_float.rep_eq
   533   real_of_float_minus -> uminus_float.rep_eq
   534   real_of_float_mult -> times_float.rep_eq
   535   real_of_float_simp -> Float.rep_eq
   536   real_of_float_sub -> minus_float.rep_eq
   537   round_down.simps -> Float.compute_float_round_down
   538   round_up.simps -> Float.compute_float_round_up
   539   times_float_def -> Float.compute_float_times
   540   uminus_float_def -> Float.compute_float_uminus
   541   zero_float_def -> Float.compute_float_zero
   542 
   543   Lemmas not necessary anymore, use the transfer method:
   544   bitlen_B0, bitlen_B1, bitlen_ge1, bitlen_Min, bitlen_Pls, float_divl,
   545   float_divr, float_le_simp, float_less1_mantissa_bound,
   546   float_less_simp, float_less_zero, float_le_zero,
   547   float_pos_less1_e_neg, float_pos_m_pos, float_split, float_split2,
   548   floor_pos_exp, lapprox_posrat, lapprox_posrat_bottom, lapprox_rat,
   549   lapprox_rat_bottom, normalized_float, rapprox_posrat,
   550   rapprox_posrat_le1, rapprox_rat, real_of_float_ge0_exp,
   551   real_of_float_neg_exp, real_of_float_nge0_exp, round_down floor_fl,
   552   round_up, zero_le_float, zero_less_float
   553 
   554 * Session HOL-Word: Discontinued many redundant theorems specific to
   555 type 'a word. INCOMPATIBILITY, use the corresponding generic theorems
   556 instead.
   557 
   558   word_sub_alt ~> word_sub_wi
   559   word_add_alt ~> word_add_def
   560   word_mult_alt ~> word_mult_def
   561   word_minus_alt ~> word_minus_def
   562   word_0_alt ~> word_0_wi
   563   word_1_alt ~> word_1_wi
   564   word_add_0 ~> add_0_left
   565   word_add_0_right ~> add_0_right
   566   word_mult_1 ~> mult_1_left
   567   word_mult_1_right ~> mult_1_right
   568   word_add_commute ~> add_commute
   569   word_add_assoc ~> add_assoc
   570   word_add_left_commute ~> add_left_commute
   571   word_mult_commute ~> mult_commute
   572   word_mult_assoc ~> mult_assoc
   573   word_mult_left_commute ~> mult_left_commute
   574   word_left_distrib ~> left_distrib
   575   word_right_distrib ~> right_distrib
   576   word_left_minus ~> left_minus
   577   word_diff_0_right ~> diff_0_right
   578   word_diff_self ~> diff_self
   579   word_sub_def ~> diff_minus
   580   word_diff_minus ~> diff_minus
   581   word_add_ac ~> add_ac
   582   word_mult_ac ~> mult_ac
   583   word_plus_ac0 ~> add_0_left add_0_right add_ac
   584   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
   585   word_order_trans ~> order_trans
   586   word_order_refl ~> order_refl
   587   word_order_antisym ~> order_antisym
   588   word_order_linear ~> linorder_linear
   589   lenw1_zero_neq_one ~> zero_neq_one
   590   word_number_of_eq ~> number_of_eq
   591   word_of_int_add_hom ~> wi_hom_add
   592   word_of_int_sub_hom ~> wi_hom_sub
   593   word_of_int_mult_hom ~> wi_hom_mult
   594   word_of_int_minus_hom ~> wi_hom_neg
   595   word_of_int_succ_hom ~> wi_hom_succ
   596   word_of_int_pred_hom ~> wi_hom_pred
   597   word_of_int_0_hom ~> word_0_wi
   598   word_of_int_1_hom ~> word_1_wi
   599 
   600 * New proof method "word_bitwise" for splitting machine word
   601 equalities and inequalities into logical circuits, defined in
   602 HOL/Word/WordBitwise.thy.  Supports addition, subtraction,
   603 multiplication, shifting by constants, bitwise operators and numeric
   604 constants.  Requires fixed-length word types, not 'a word.  Solves
   605 many standard word identies outright and converts more into first
   606 order problems amenable to blast or similar.  See also examples in
   607 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
   662 represent measures, this replaces the records 'a algebra and 'a
   663 measure_space.  The locales based on subset_class now have two
   664 locale-parameters the space \<Omega> and the set of measurables sets
   665 M.  The product of probability spaces uses now the same constant as
   666 the finite product of sigma-finite measure spaces "PiM :: ('i => 'a)
   667 measure".  Most constants are defined now outside of locales and gain
   668 an additional parameter, like null_sets, almost_eventually or \<mu>'.
   669 Measure space constructions for distributions and densities now got
   670 their own constants distr and density.  Instead of using locales to
   671 describe measure spaces with a finite space, the measure count_space
   672 and point_measure is introduced.  INCOMPATIBILITY.
   673 
   674   Renamed constants:
   675   measure -> emeasure
   676   finite_measure.\<mu>' -> measure
   677   product_algebra_generator -> prod_algebra
   678   product_prob_space.emb -> prod_emb
   679   product_prob_space.infprod_algebra -> PiM
   680 
   681   Removed locales:
   682   completeable_measure_space
   683   finite_measure_space
   684   finite_prob_space
   685   finite_product_finite_prob_space
   686   finite_product_sigma_algebra
   687   finite_sigma_algebra
   688   measure_space
   689   pair_finite_prob_space
   690   pair_finite_sigma_algebra
   691   pair_finite_space
   692   pair_sigma_algebra
   693   product_sigma_algebra
   694 
   695   Removed constants:
   696   conditional_space
   697   distribution -> use distr measure, or distributed predicate
   698   image_space
   699   joint_distribution -> use distr measure, or distributed predicate
   700   pair_measure_generator
   701   product_prob_space.infprod_algebra -> use PiM
   702   subvimage
   703 
   704   Replacement theorems:
   705   finite_additivity_sufficient -> ring_of_sets.countably_additiveI_finite
   706   finite_measure.empty_measure -> measure_empty
   707   finite_measure.finite_continuity_from_above -> finite_measure.finite_Lim_measure_decseq
   708   finite_measure.finite_continuity_from_below -> finite_measure.finite_Lim_measure_incseq
   709   finite_measure.finite_measure_countably_subadditive -> finite_measure.finite_measure_subadditive_countably
   710   finite_measure.finite_measure_eq -> finite_measure.emeasure_eq_measure
   711   finite_measure.finite_measure -> finite_measure.emeasure_finite
   712   finite_measure.finite_measure_finite_singleton -> finite_measure.finite_measure_eq_setsum_singleton
   713   finite_measure.positive_measure' -> measure_nonneg
   714   finite_measure.real_measure -> finite_measure.emeasure_real
   715   finite_product_prob_space.finite_measure_times -> finite_product_prob_space.finite_measure_PiM_emb
   716   finite_product_sigma_algebra.in_P -> sets_PiM_I_finite
   717   finite_product_sigma_algebra.P_empty -> space_PiM_empty, sets_PiM_empty
   718   information_space.conditional_entropy_eq -> information_space.conditional_entropy_simple_distributed
   719   information_space.conditional_entropy_positive -> information_space.conditional_entropy_nonneg_simple
   720   information_space.conditional_mutual_information_eq_mutual_information -> information_space.conditional_mutual_information_eq_mutual_information_simple
   721   information_space.conditional_mutual_information_generic_positive -> information_space.conditional_mutual_information_nonneg_simple
   722   information_space.conditional_mutual_information_positive -> information_space.conditional_mutual_information_nonneg_simple
   723   information_space.entropy_commute -> information_space.entropy_commute_simple
   724   information_space.entropy_eq -> information_space.entropy_simple_distributed
   725   information_space.entropy_generic_eq -> information_space.entropy_simple_distributed
   726   information_space.entropy_positive -> information_space.entropy_nonneg_simple
   727   information_space.entropy_uniform_max -> information_space.entropy_uniform
   728   information_space.KL_eq_0_imp -> information_space.KL_eq_0_iff_eq
   729   information_space.KL_eq_0 -> information_space.KL_same_eq_0
   730   information_space.KL_ge_0 -> information_space.KL_nonneg
   731   information_space.mutual_information_eq -> information_space.mutual_information_simple_distributed
   732   information_space.mutual_information_positive -> information_space.mutual_information_nonneg_simple
   733   Int_stable_cuboids -> Int_stable_atLeastAtMost
   734   Int_stable_product_algebra_generator -> positive_integral
   735   measure_preserving -> equality "distr M N f = N" "f : measurable M N"
   736   measure_space.additive -> emeasure_additive
   737   measure_space.AE_iff_null_set -> AE_iff_null
   738   measure_space.almost_everywhere_def -> eventually_ae_filter
   739   measure_space.almost_everywhere_vimage -> AE_distrD
   740   measure_space.continuity_from_above -> INF_emeasure_decseq
   741   measure_space.continuity_from_above_Lim -> Lim_emeasure_decseq
   742   measure_space.continuity_from_below_Lim -> Lim_emeasure_incseq
   743   measure_space.continuity_from_below -> SUP_emeasure_incseq
   744   measure_space_density -> emeasure_density
   745   measure_space.density_is_absolutely_continuous -> absolutely_continuousI_density
   746   measure_space.integrable_vimage -> integrable_distr
   747   measure_space.integral_translated_density -> integral_density
   748   measure_space.integral_vimage -> integral_distr
   749   measure_space.measure_additive -> plus_emeasure
   750   measure_space.measure_compl -> emeasure_compl
   751   measure_space.measure_countable_increasing -> emeasure_countable_increasing
   752   measure_space.measure_countably_subadditive -> emeasure_subadditive_countably
   753   measure_space.measure_decseq -> decseq_emeasure
   754   measure_space.measure_Diff -> emeasure_Diff
   755   measure_space.measure_Diff_null_set -> emeasure_Diff_null_set
   756   measure_space.measure_eq_0 -> emeasure_eq_0
   757   measure_space.measure_finitely_subadditive -> emeasure_subadditive_finite
   758   measure_space.measure_finite_singleton -> emeasure_eq_setsum_singleton
   759   measure_space.measure_incseq -> incseq_emeasure
   760   measure_space.measure_insert -> emeasure_insert
   761   measure_space.measure_mono -> emeasure_mono
   762   measure_space.measure_not_negative -> emeasure_not_MInf
   763   measure_space.measure_preserving_Int_stable -> measure_eqI_generator_eq
   764   measure_space.measure_setsum -> setsum_emeasure
   765   measure_space.measure_setsum_split -> setsum_emeasure_cover
   766   measure_space.measure_space_vimage -> emeasure_distr
   767   measure_space.measure_subadditive_finite -> emeasure_subadditive_finite
   768   measure_space.measure_subadditive -> subadditive
   769   measure_space.measure_top -> emeasure_space
   770   measure_space.measure_UN_eq_0 -> emeasure_UN_eq_0
   771   measure_space.measure_Un_null_set -> emeasure_Un_null_set
   772   measure_space.positive_integral_translated_density -> positive_integral_density
   773   measure_space.positive_integral_vimage -> positive_integral_distr
   774   measure_space.real_continuity_from_above -> Lim_measure_decseq
   775   measure_space.real_continuity_from_below -> Lim_measure_incseq
   776   measure_space.real_measure_countably_subadditive -> measure_subadditive_countably
   777   measure_space.real_measure_Diff -> measure_Diff
   778   measure_space.real_measure_finite_Union -> measure_finite_Union
   779   measure_space.real_measure_setsum_singleton -> measure_eq_setsum_singleton
   780   measure_space.real_measure_subadditive -> measure_subadditive
   781   measure_space.real_measure_Union -> measure_Union
   782   measure_space.real_measure_UNION -> measure_UNION
   783   measure_space.simple_function_vimage -> simple_function_comp
   784   measure_space.simple_integral_vimage -> simple_integral_distr
   785   measure_space.simple_integral_vimage -> simple_integral_distr
   786   measure_unique_Int_stable -> measure_eqI_generator_eq
   787   measure_unique_Int_stable_vimage -> measure_eqI_generator_eq
   788   pair_sigma_algebra.measurable_cut_fst -> sets_Pair1
   789   pair_sigma_algebra.measurable_cut_snd -> sets_Pair2
   790   pair_sigma_algebra.measurable_pair_image_fst -> measurable_Pair1
   791   pair_sigma_algebra.measurable_pair_image_snd -> measurable_Pair2
   792   pair_sigma_algebra.measurable_product_swap -> measurable_pair_swap_iff
   793   pair_sigma_algebra.pair_sigma_algebra_measurable -> measurable_pair_swap
   794   pair_sigma_algebra.pair_sigma_algebra_swap_measurable -> measurable_pair_swap'
   795   pair_sigma_algebra.sets_swap -> sets_pair_swap
   796   pair_sigma_finite.measure_cut_measurable_fst -> pair_sigma_finite.measurable_emeasure_Pair1
   797   pair_sigma_finite.measure_cut_measurable_snd -> pair_sigma_finite.measurable_emeasure_Pair2
   798   pair_sigma_finite.measure_preserving_swap -> pair_sigma_finite.distr_pair_swap
   799   pair_sigma_finite.pair_measure_alt2 -> pair_sigma_finite.emeasure_pair_measure_alt2
   800   pair_sigma_finite.pair_measure_alt -> pair_sigma_finite.emeasure_pair_measure_alt
   801   pair_sigma_finite.pair_measure_times -> pair_sigma_finite.emeasure_pair_measure_Times
   802   prob_space.indep_distribution_eq_measure -> prob_space.indep_vars_iff_distr_eq_PiM
   803   prob_space.indep_var_distributionD -> prob_space.indep_var_distribution_eq
   804   prob_space.measure_space_1 -> prob_space.emeasure_space_1
   805   prob_space.prob_space_vimage -> prob_space_distr
   806   prob_space.random_variable_restrict -> measurable_restrict
   807   prob_space_unique_Int_stable -> measure_eqI_prob_space
   808   product_algebraE -> prod_algebraE_all
   809   product_algebra_generator_der -> prod_algebra_eq_finite
   810   product_algebra_generator_into_space -> prod_algebra_sets_into_space
   811   product_algebraI -> sets_PiM_I_finite
   812   product_measure_exists -> product_sigma_finite.sigma_finite
   813   product_prob_space.finite_index_eq_finite_product -> product_prob_space.sets_PiM_generator
   814   product_prob_space.finite_measure_infprod_emb_Pi -> product_prob_space.measure_PiM_emb
   815   product_prob_space.infprod_spec -> product_prob_space.emeasure_PiM_emb_not_empty
   816   product_prob_space.measurable_component -> measurable_component_singleton
   817   product_prob_space.measurable_emb -> measurable_prod_emb
   818   product_prob_space.measurable_into_infprod_algebra -> measurable_PiM_single
   819   product_prob_space.measurable_singleton_infprod -> measurable_component_singleton
   820   product_prob_space.measure_emb -> emeasure_prod_emb
   821   product_prob_space.measure_preserving_restrict -> product_prob_space.distr_restrict
   822   product_sigma_algebra.product_algebra_into_space -> space_closed
   823   product_sigma_finite.measure_fold -> product_sigma_finite.distr_merge
   824   product_sigma_finite.measure_preserving_component_singelton -> product_sigma_finite.distr_singleton
   825   product_sigma_finite.measure_preserving_merge -> product_sigma_finite.distr_merge
   826   sequence_space.measure_infprod -> sequence_space.measure_PiM_countable
   827   sets_product_algebra -> sets_PiM
   828   sigma_algebra.measurable_sigma -> measurable_measure_of
   829   sigma_finite_measure.disjoint_sigma_finite -> sigma_finite_disjoint
   830   sigma_finite_measure.RN_deriv_vimage -> sigma_finite_measure.RN_deriv_distr
   831   sigma_product_algebra_sigma_eq -> sigma_prod_algebra_sigma_eq
   832   space_product_algebra -> space_PiM
   833 
   834 * New "case_product" attribute to generate a case rule doing multiple
   835 case distinctions at the same time.  E.g.
   836 
   837   list.exhaust [case_product nat.exhaust]
   838 
   839 produces a rule which can be used to perform case distinction on both
   840 a list and a nat.
   841 
   842 * New Transfer package:
   843 
   844   - transfer_rule attribute: Maintains a collection of transfer rules,
   845     which relate constants at two different types. Transfer rules may
   846     relate different type instances of the same polymorphic constant,
   847     or they may relate an operation on a raw type to a corresponding
   848     operation on an abstract type (quotient or subtype). For example:
   849 
   850     ((A ===> B) ===> list_all2 A ===> list_all2 B) map map
   851     (cr_int ===> cr_int ===> cr_int) (%(x,y) (u,v). (x+u, y+v)) plus_int
   852 
   853   - transfer method: Replaces a subgoal on abstract types with an
   854     equivalent subgoal on the corresponding raw types. Constants are
   855     replaced with corresponding ones according to the transfer rules.
   856     Goals are generalized over all free variables by default; this is
   857     necessary for variables whose types changes, but can be overridden
   858     for specific variables with e.g. 'transfer fixing: x y z'.  The
   859     variant transfer' method allows replacing a subgoal with one that
   860     is logically stronger (rather than equivalent).
   861 
   862   - relator_eq attribute: Collects identity laws for relators of
   863     various type constructors, e.g. "list_all2 (op =) = (op =)".  The
   864     transfer method uses these lemmas to infer transfer rules for
   865     non-polymorphic constants on the fly.
   866 
   867   - transfer_prover method: Assists with proving a transfer rule for a
   868     new constant, provided the constant is defined in terms of other
   869     constants that already have transfer rules. It should be applied
   870     after unfolding the constant definitions.
   871 
   872   - HOL/ex/Transfer_Int_Nat.thy: Example theory demonstrating transfer
   873     from type nat to type int.
   874 
   875 * New Lifting package:
   876 
   877   - lift_definition command: Defines operations on an abstract type in
   878     terms of a corresponding operation on a representation
   879     type.  Example syntax:
   880 
   881     lift_definition dlist_insert :: "'a => 'a dlist => 'a dlist"
   882       is List.insert
   883 
   884     Users must discharge a respectfulness proof obligation when each
   885     constant is defined. (For a type copy, i.e. a typedef with UNIV,
   886     the proof is discharged automatically.) The obligation is
   887     presented in a user-friendly, readable form; a respectfulness
   888     theorem in the standard format and a transfer rule are generated
   889     by the package.
   890 
   891   - Integration with code_abstype: For typedefs (e.g. subtypes
   892     corresponding to a datatype invariant, such as dlist),
   893     lift_definition generates a code certificate theorem and sets up
   894     code generation for each constant.
   895 
   896   - setup_lifting command: Sets up the Lifting package to work with a
   897     user-defined type. The user must provide either a quotient theorem
   898     or a type_definition theorem.  The package configures transfer
   899     rules for equality and quantifiers on the type, and sets up the
   900     lift_definition command to work with the type.
   901 
   902   - Usage examples: See Quotient_Examples/Lift_DList.thy,
   903     Quotient_Examples/Lift_RBT.thy, Word/Word.thy and
   904     Library/Float.thy.
   905 
   906 * Quotient package:
   907 
   908   - The 'quotient_type' command now supports a 'morphisms' option with
   909     rep and abs functions, similar to typedef.
   910 
   911   - 'quotient_type' sets up new types to work with the Lifting and
   912     Transfer packages, as with 'setup_lifting'.
   913 
   914   - The 'quotient_definition' command now requires the user to prove a
   915     respectfulness property at the point where the constant is
   916     defined, similar to lift_definition; INCOMPATIBILITY.
   917 
   918   - Renamed predicate 'Quotient' to 'Quotient3', and renamed theorems
   919     accordingly, INCOMPATIBILITY.
   920 
   921 * New diagnostic command 'find_unused_assms' to find potentially
   922 superfluous assumptions in theorems using Quickcheck.
   923 
   924 * Quickcheck:
   925 
   926   - Quickcheck returns variable assignments as counterexamples, which
   927     allows to reveal the underspecification of functions under test.
   928     For example, refuting "hd xs = x", it presents the variable
   929     assignment xs = [] and x = a1 as a counterexample, assuming that
   930     any property is false whenever "hd []" occurs in it.
   931 
   932     These counterexample are marked as potentially spurious, as
   933     Quickcheck also returns "xs = []" as a counterexample to the
   934     obvious theorem "hd xs = hd xs".
   935 
   936     After finding a potentially spurious counterexample, Quickcheck
   937     continues searching for genuine ones.
   938 
   939     By default, Quickcheck shows potentially spurious and genuine
   940     counterexamples. The option "genuine_only" sets quickcheck to only
   941     show genuine counterexamples.
   942 
   943   - The command 'quickcheck_generator' creates random and exhaustive
   944     value generators for a given type and operations.
   945 
   946     It generates values by using the operations as if they were
   947     constructors of that type.
   948 
   949   - Support for multisets.
   950 
   951   - Added "use_subtype" options.
   952 
   953   - Added "quickcheck_locale" configuration to specify how to process
   954     conjectures in a locale context.
   955 
   956 * Nitpick:
   957   - Fixed infinite loop caused by the 'peephole_optim' option and
   958     affecting 'rat' and 'real'.
   959 
   960 * Sledgehammer:
   961   - Integrated more tightly with SPASS, as described in the ITP 2012
   962     paper "More SPASS with Isabelle".
   963   - Made it try "smt" as a fallback if "metis" fails or times out.
   964   - Added support for the following provers: Alt-Ergo (via Why3 and
   965     TFF1), iProver, iProver-Eq.
   966   - Replaced remote E-SInE with remote Satallax in the default setup.
   967   - Sped up the minimizer.
   968   - Added "lam_trans", "uncurry_aliases", and "minimize" options.
   969   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   970   - Renamed "sound" option to "strict".
   971 
   972 * Metis:
   973   - Added possibility to specify lambda translations scheme as a
   974     parenthesized argument (e.g., "by (metis (lifting) ...)").
   975 
   976 * SMT:
   977   - Renamed "smt_fixed" option to "smt_read_only_certificates".
   978 
   979 * Command 'try0':
   980   - Renamed from 'try_methods'. INCOMPATIBILITY.
   981 
   982 * New "eventually_elim" method as a generalized variant of the
   983 eventually_elim* rules. Supports structured proofs.
   984 
   985 * HOL/TPTP: support to parse and import TPTP problems (all languages)
   986 into Isabelle/HOL.
   987 
   988 
   989 *** FOL ***
   990 
   991 * New "case_product" attribute (see HOL).
   992 
   993 
   994 *** ZF ***
   995 
   996 * Greater support for structured proofs involving induction or case
   997 analysis.
   998 
   999 * Much greater use of mathematical symbols.
  1000 
  1001 * Removal of many ML theorem bindings.  INCOMPATIBILITY.
  1002 
  1003 
  1004 *** ML ***
  1005 
  1006 * Antiquotation @{keyword "name"} produces a parser for outer syntax
  1007 from a minor keyword introduced via theory header declaration.
  1008 
  1009 * Antiquotation @{command_spec "name"} produces the
  1010 Outer_Syntax.command_spec from a major keyword introduced via theory
  1011 header declaration; it can be passed to Outer_Syntax.command etc.
  1012 
  1013 * Local_Theory.define no longer hard-wires default theorem name
  1014 "foo_def", but retains the binding as given.  If that is Binding.empty
  1015 / Attrib.empty_binding, the result is not registered as user-level
  1016 fact.  The Local_Theory.define_internal variant allows to specify a
  1017 non-empty name (used for the foundation in the background theory),
  1018 while omitting the fact binding in the user-context.  Potential
  1019 INCOMPATIBILITY for derived definitional packages: need to specify
  1020 naming policy for primitive definitions more explicitly.
  1021 
  1022 * Renamed Thm.capply to Thm.apply, and Thm.cabs to Thm.lambda in
  1023 conformance with similar operations in structure Term and Logic.
  1024 
  1025 * Antiquotation @{attributes [...]} embeds attribute source
  1026 representation into the ML text, which is particularly useful with
  1027 declarations like Local_Theory.note.
  1028 
  1029 * Structure Proof_Context follows standard naming scheme.  Old
  1030 ProofContext has been discontinued.  INCOMPATIBILITY.
  1031 
  1032 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
  1033 change of semantics: update is applied to auxiliary local theory
  1034 context as well.
  1035 
  1036 * Modernized some old-style infix operations:
  1037 
  1038   addeqcongs    ~> Simplifier.add_eqcong
  1039   deleqcongs    ~> Simplifier.del_eqcong
  1040   addcongs      ~> Simplifier.add_cong
  1041   delcongs      ~> Simplifier.del_cong
  1042   setmksimps    ~> Simplifier.set_mksimps
  1043   setmkcong     ~> Simplifier.set_mkcong
  1044   setmksym      ~> Simplifier.set_mksym
  1045   setmkeqTrue   ~> Simplifier.set_mkeqTrue
  1046   settermless   ~> Simplifier.set_termless
  1047   setsubgoaler  ~> Simplifier.set_subgoaler
  1048   addsplits     ~> Splitter.add_split
  1049   delsplits     ~> Splitter.del_split
  1050 
  1051 
  1052 *** System ***
  1053 
  1054 * USER_HOME settings variable points to cross-platform user home
  1055 directory, which coincides with HOME on POSIX systems only.  Likewise,
  1056 the Isabelle path specification "~" now expands to $USER_HOME, instead
  1057 of former $HOME.  A different default for USER_HOME may be set
  1058 explicitly in shell environment, before Isabelle settings are
  1059 evaluated.  Minor INCOMPATIBILITY: need to adapt Isabelle path where
  1060 the generic user home was intended.
  1061 
  1062 * ISABELLE_HOME_WINDOWS refers to ISABELLE_HOME in windows file name
  1063 notation, which is useful for the jEdit file browser, for example.
  1064 
  1065 * ISABELLE_JDK_HOME settings variable points to JDK with javac and jar
  1066 (not just JRE).
  1067 
  1068 
  1069 
  1070 New in Isabelle2011-1 (October 2011)
  1071 ------------------------------------
  1072 
  1073 *** General ***
  1074 
  1075 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
  1076 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
  1077 
  1078   - Management of multiple theory files directly from the editor
  1079     buffer store -- bypassing the file-system (no requirement to save
  1080     files for checking).
  1081 
  1082   - Markup of formal entities within the text buffer, with semantic
  1083     highlighting, tooltips and hyperlinks to jump to defining source
  1084     positions.
  1085 
  1086   - Improved text rendering, with sub/superscripts in the source
  1087     buffer (including support for copy/paste wrt. output panel, HTML
  1088     theory output and other non-Isabelle text boxes).
  1089 
  1090   - Refined scheduling of proof checking and printing of results,
  1091     based on interactive editor view.  (Note: jEdit folding and
  1092     narrowing allows to restrict buffer perspectives explicitly.)
  1093 
  1094   - Reduced CPU performance requirements, usable on machines with few
  1095     cores.
  1096 
  1097   - Reduced memory requirements due to pruning of unused document
  1098     versions (garbage collection).
  1099 
  1100 See also ~~/src/Tools/jEdit/README.html for further information,
  1101 including some remaining limitations.
  1102 
  1103 * Theory loader: source files are exclusively located via the master
  1104 directory of each theory node (where the .thy file itself resides).
  1105 The global load path (such as src/HOL/Library) has been discontinued.
  1106 Note that the path element ~~ may be used to reference theories in the
  1107 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
  1108 INCOMPATIBILITY.
  1109 
  1110 * Theory loader: source files are identified by content via SHA1
  1111 digests.  Discontinued former path/modtime identification and optional
  1112 ISABELLE_FILE_IDENT plugin scripts.
  1113 
  1114 * Parallelization of nested Isar proofs is subject to
  1115 Goal.parallel_proofs_threshold (default 100).  See also isabelle
  1116 usedir option -Q.
  1117 
  1118 * Name space: former unsynchronized references are now proper
  1119 configuration options, with more conventional names:
  1120 
  1121   long_names   ~> names_long
  1122   short_names  ~> names_short
  1123   unique_names ~> names_unique
  1124 
  1125 Minor INCOMPATIBILITY, need to declare options in context like this:
  1126 
  1127   declare [[names_unique = false]]
  1128 
  1129 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
  1130 that the result needs to be unique, which means fact specifications
  1131 may have to be refined after enriching a proof context.
  1132 
  1133 * Attribute "case_names" has been refined: the assumptions in each case
  1134 can be named now by following the case name with [name1 name2 ...].
  1135 
  1136 * Isabelle/Isar reference manual has been updated and extended:
  1137   - "Synopsis" provides a catalog of main Isar language concepts.
  1138   - Formal references in syntax diagrams, via @{rail} antiquotation.
  1139   - Updated material from classic "ref" manual, notably about
  1140     "Classical Reasoner".
  1141 
  1142 
  1143 *** HOL ***
  1144 
  1145 * Class bot and top require underlying partial order rather than
  1146 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
  1147 
  1148 * Class complete_lattice: generalized a couple of lemmas from sets;
  1149 generalized theorems INF_cong and SUP_cong.  New type classes for
  1150 complete boolean algebras and complete linear orders.  Lemmas
  1151 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
  1152 class complete_linorder.
  1153 
  1154 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
  1155 Sup_fun_def, Inf_apply, Sup_apply.
  1156 
  1157 Removed redundant lemmas (the right hand side gives hints how to
  1158 replace them for (metis ...), or (simp only: ...) proofs):
  1159 
  1160   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
  1161   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
  1162   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
  1163   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
  1164   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
  1165   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
  1166   Inter_def ~> INF_def, image_def
  1167   Union_def ~> SUP_def, image_def
  1168   INT_eq ~> INF_def, and image_def
  1169   UN_eq ~> SUP_def, and image_def
  1170   INF_subset ~> INF_superset_mono [OF _ order_refl]
  1171 
  1172 More consistent and comprehensive names:
  1173 
  1174   INTER_eq_Inter_image ~> INF_def
  1175   UNION_eq_Union_image ~> SUP_def
  1176   INFI_def ~> INF_def
  1177   SUPR_def ~> SUP_def
  1178   INF_leI ~> INF_lower
  1179   INF_leI2 ~> INF_lower2
  1180   le_INFI ~> INF_greatest
  1181   le_SUPI ~> SUP_upper
  1182   le_SUPI2 ~> SUP_upper2
  1183   SUP_leI ~> SUP_least
  1184   INFI_bool_eq ~> INF_bool_eq
  1185   SUPR_bool_eq ~> SUP_bool_eq
  1186   INFI_apply ~> INF_apply
  1187   SUPR_apply ~> SUP_apply
  1188   INTER_def ~> INTER_eq
  1189   UNION_def ~> UNION_eq
  1190 
  1191 INCOMPATIBILITY.
  1192 
  1193 * Renamed theory Complete_Lattice to Complete_Lattices.
  1194 INCOMPATIBILITY.
  1195 
  1196 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
  1197 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
  1198 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
  1199 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
  1200 
  1201 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
  1202 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
  1203 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
  1204 INCOMPATIBILITY.
  1205 
  1206 * Added syntactic classes "inf" and "sup" for the respective
  1207 constants.  INCOMPATIBILITY: Changes in the argument order of the
  1208 (mostly internal) locale predicates for some derived classes.
  1209 
  1210 * Theorem collections ball_simps and bex_simps do not contain theorems
  1211 referring to UNION any longer; these have been moved to collection
  1212 UN_ball_bex_simps.  INCOMPATIBILITY.
  1213 
  1214 * Theory Archimedean_Field: floor now is defined as parameter of a
  1215 separate type class floor_ceiling.
  1216 
  1217 * Theory Finite_Set: more coherent development of fold_set locales:
  1218 
  1219     locale fun_left_comm ~> locale comp_fun_commute
  1220     locale fun_left_comm_idem ~> locale comp_fun_idem
  1221 
  1222 Both use point-free characterization; interpretation proofs may need
  1223 adjustment.  INCOMPATIBILITY.
  1224 
  1225 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
  1226 accordance with standard mathematical terminology. INCOMPATIBILITY.
  1227 
  1228 * Theory Complex_Main: The locale interpretations for the
  1229 bounded_linear and bounded_bilinear locales have been removed, in
  1230 order to reduce the number of duplicate lemmas. Users must use the
  1231 original names for distributivity theorems, potential INCOMPATIBILITY.
  1232 
  1233   divide.add ~> add_divide_distrib
  1234   divide.diff ~> diff_divide_distrib
  1235   divide.setsum ~> setsum_divide_distrib
  1236   mult.add_right ~> right_distrib
  1237   mult.diff_right ~> right_diff_distrib
  1238   mult_right.setsum ~> setsum_right_distrib
  1239   mult_left.diff ~> left_diff_distrib
  1240 
  1241 * Theory Complex_Main: Several redundant theorems have been removed or
  1242 replaced by more general versions. INCOMPATIBILITY.
  1243 
  1244   real_diff_def ~> minus_real_def
  1245   real_divide_def ~> divide_real_def
  1246   real_less_def ~> less_le
  1247   real_abs_def ~> abs_real_def
  1248   real_sgn_def ~> sgn_real_def
  1249   real_mult_commute ~> mult_commute
  1250   real_mult_assoc ~> mult_assoc
  1251   real_mult_1 ~> mult_1_left
  1252   real_add_mult_distrib ~> left_distrib
  1253   real_zero_not_eq_one ~> zero_neq_one
  1254   real_mult_inverse_left ~> left_inverse
  1255   INVERSE_ZERO ~> inverse_zero
  1256   real_le_refl ~> order_refl
  1257   real_le_antisym ~> order_antisym
  1258   real_le_trans ~> order_trans
  1259   real_le_linear ~> linear
  1260   real_le_eq_diff ~> le_iff_diff_le_0
  1261   real_add_left_mono ~> add_left_mono
  1262   real_mult_order ~> mult_pos_pos
  1263   real_mult_less_mono2 ~> mult_strict_left_mono
  1264   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
  1265   real_0_le_divide_iff ~> zero_le_divide_iff
  1266   realpow_two_disj ~> power2_eq_iff
  1267   real_squared_diff_one_factored ~> square_diff_one_factored
  1268   realpow_two_diff ~> square_diff_square_factored
  1269   reals_complete2 ~> complete_real
  1270   real_sum_squared_expand ~> power2_sum
  1271   exp_ln_eq ~> ln_unique
  1272   expi_add ~> exp_add
  1273   expi_zero ~> exp_zero
  1274   lemma_DERIV_subst ~> DERIV_cong
  1275   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
  1276   LIMSEQ_const ~> tendsto_const
  1277   LIMSEQ_norm ~> tendsto_norm
  1278   LIMSEQ_add ~> tendsto_add
  1279   LIMSEQ_minus ~> tendsto_minus
  1280   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
  1281   LIMSEQ_diff ~> tendsto_diff
  1282   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
  1283   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
  1284   LIMSEQ_mult ~> tendsto_mult
  1285   LIMSEQ_inverse ~> tendsto_inverse
  1286   LIMSEQ_divide ~> tendsto_divide
  1287   LIMSEQ_pow ~> tendsto_power
  1288   LIMSEQ_setsum ~> tendsto_setsum
  1289   LIMSEQ_setprod ~> tendsto_setprod
  1290   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
  1291   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
  1292   LIMSEQ_imp_rabs ~> tendsto_rabs
  1293   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
  1294   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
  1295   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
  1296   LIMSEQ_Complex ~> tendsto_Complex
  1297   LIM_ident ~> tendsto_ident_at
  1298   LIM_const ~> tendsto_const
  1299   LIM_add ~> tendsto_add
  1300   LIM_add_zero ~> tendsto_add_zero
  1301   LIM_minus ~> tendsto_minus
  1302   LIM_diff ~> tendsto_diff
  1303   LIM_norm ~> tendsto_norm
  1304   LIM_norm_zero ~> tendsto_norm_zero
  1305   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
  1306   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
  1307   LIM_rabs ~> tendsto_rabs
  1308   LIM_rabs_zero ~> tendsto_rabs_zero
  1309   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
  1310   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
  1311   LIM_compose ~> tendsto_compose
  1312   LIM_mult ~> tendsto_mult
  1313   LIM_scaleR ~> tendsto_scaleR
  1314   LIM_of_real ~> tendsto_of_real
  1315   LIM_power ~> tendsto_power
  1316   LIM_inverse ~> tendsto_inverse
  1317   LIM_sgn ~> tendsto_sgn
  1318   isCont_LIM_compose ~> isCont_tendsto_compose
  1319   bounded_linear.LIM ~> bounded_linear.tendsto
  1320   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
  1321   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
  1322   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
  1323   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
  1324   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
  1325   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
  1326 
  1327 * Theory Complex_Main: The definition of infinite series was
  1328 generalized.  Now it is defined on the type class {topological_space,
  1329 comm_monoid_add}.  Hence it is useable also for extended real numbers.
  1330 
  1331 * Theory Complex_Main: The complex exponential function "expi" is now
  1332 a type-constrained abbreviation for "exp :: complex => complex"; thus
  1333 several polymorphic lemmas about "exp" are now applicable to "expi".
  1334 
  1335 * Code generation:
  1336 
  1337   - Theory Library/Code_Char_ord provides native ordering of
  1338     characters in the target language.
  1339 
  1340   - Commands code_module and code_library are legacy, use export_code
  1341     instead.
  1342 
  1343   - Method "evaluation" is legacy, use method "eval" instead.
  1344 
  1345   - Legacy evaluator "SML" is deactivated by default.  May be
  1346     reactivated by the following theory command:
  1347 
  1348       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
  1349 
  1350 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
  1351 
  1352 * New proof method "induction" that gives induction hypotheses the
  1353 name "IH", thus distinguishing them from further hypotheses that come
  1354 from rule induction.  The latter are still called "hyps".  Method
  1355 "induction" is a thin wrapper around "induct" and follows the same
  1356 syntax.
  1357 
  1358 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
  1359 still available as a legacy feature for some time.
  1360 
  1361 * Nitpick:
  1362   - Added "need" and "total_consts" options.
  1363   - Reintroduced "show_skolems" option by popular demand.
  1364   - Renamed attribute: nitpick_def ~> nitpick_unfold.
  1365     INCOMPATIBILITY.
  1366 
  1367 * Sledgehammer:
  1368   - Use quasi-sound (and efficient) translations by default.
  1369   - Added support for the following provers: E-ToFoF, LEO-II,
  1370     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
  1371   - Automatically preplay and minimize proofs before showing them if
  1372     this can be done within reasonable time.
  1373   - sledgehammer available_provers ~> sledgehammer supported_provers.
  1374     INCOMPATIBILITY.
  1375   - Added "preplay_timeout", "slicing", "type_enc", "sound",
  1376     "max_mono_iters", and "max_new_mono_instances" options.
  1377   - Removed "explicit_apply" and "full_types" options as well as "Full
  1378     Types" Proof General menu item. INCOMPATIBILITY.
  1379 
  1380 * Metis:
  1381   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
  1382   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
  1383     INCOMPATIBILITY.
  1384 
  1385 * Command 'try':
  1386   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
  1387     "elim:" options. INCOMPATIBILITY.
  1388   - Introduced 'try' that not only runs 'try_methods' but also
  1389     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
  1390 
  1391 * Quickcheck:
  1392   - Added "eval" option to evaluate terms for the found counterexample
  1393     (currently only supported by the default (exhaustive) tester).
  1394   - Added post-processing of terms to obtain readable counterexamples
  1395     (currently only supported by the default (exhaustive) tester).
  1396   - New counterexample generator quickcheck[narrowing] enables
  1397     narrowing-based testing.  Requires the Glasgow Haskell compiler
  1398     with its installation location defined in the Isabelle settings
  1399     environment as ISABELLE_GHC.
  1400   - Removed quickcheck tester "SML" based on the SML code generator
  1401     (formly in HOL/Library).
  1402 
  1403 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
  1404 use 'partial_function' instead.
  1405 
  1406 * Theory Library/Extended_Reals replaces now the positive extended
  1407 reals found in probability theory. This file is extended by
  1408 Multivariate_Analysis/Extended_Real_Limits.
  1409 
  1410 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
  1411 from where it must be imported explicitly if it is really required.
  1412 INCOMPATIBILITY.
  1413 
  1414 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
  1415 been moved here.  INCOMPATIBILITY.
  1416 
  1417 * Theory Library/Saturated provides type of numbers with saturated
  1418 arithmetic.
  1419 
  1420 * Theory Library/Product_Lattice defines a pointwise ordering for the
  1421 product type 'a * 'b, and provides instance proofs for various order
  1422 and lattice type classes.
  1423 
  1424 * Theory Library/Countable now provides the "countable_datatype" proof
  1425 method for proving "countable" class instances for datatypes.
  1426 
  1427 * Theory Library/Cset_Monad allows do notation for computable sets
  1428 (cset) via the generic monad ad-hoc overloading facility.
  1429 
  1430 * Library: Theories of common data structures are split into theories
  1431 for implementation, an invariant-ensuring type, and connection to an
  1432 abstract type. INCOMPATIBILITY.
  1433 
  1434   - RBT is split into RBT and RBT_Mapping.
  1435   - AssocList is split and renamed into AList and AList_Mapping.
  1436   - DList is split into DList_Impl, DList, and DList_Cset.
  1437   - Cset is split into Cset and List_Cset.
  1438 
  1439 * Theory Library/Nat_Infinity has been renamed to
  1440 Library/Extended_Nat, with name changes of the following types and
  1441 constants:
  1442 
  1443   type inat   ~> type enat
  1444   Fin         ~> enat
  1445   Infty       ~> infinity (overloaded)
  1446   iSuc        ~> eSuc
  1447   the_Fin     ~> the_enat
  1448 
  1449 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
  1450 been renamed accordingly. INCOMPATIBILITY.
  1451 
  1452 * Session Multivariate_Analysis: The euclidean_space type class now
  1453 fixes a constant "Basis :: 'a set" consisting of the standard
  1454 orthonormal basis for the type. Users now have the option of
  1455 quantifying over this set instead of using the "basis" function, e.g.
  1456 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
  1457 
  1458 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
  1459 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
  1460 "Cart_nth" and "Cart_lambda" have been respectively renamed to
  1461 "vec_nth" and "vec_lambda"; theorems mentioning those names have
  1462 changed to match. Definition theorems for overloaded constants now use
  1463 the standard "foo_vec_def" naming scheme. A few other theorems have
  1464 been renamed as follows (INCOMPATIBILITY):
  1465 
  1466   Cart_eq          ~> vec_eq_iff
  1467   dist_nth_le_cart ~> dist_vec_nth_le
  1468   tendsto_vector   ~> vec_tendstoI
  1469   Cauchy_vector    ~> vec_CauchyI
  1470 
  1471 * Session Multivariate_Analysis: Several duplicate theorems have been
  1472 removed, and other theorems have been renamed or replaced with more
  1473 general versions. INCOMPATIBILITY.
  1474 
  1475   finite_choice ~> finite_set_choice
  1476   eventually_conjI ~> eventually_conj
  1477   eventually_and ~> eventually_conj_iff
  1478   eventually_false ~> eventually_False
  1479   setsum_norm ~> norm_setsum
  1480   Lim_sequentially ~> LIMSEQ_def
  1481   Lim_ident_at ~> LIM_ident
  1482   Lim_const ~> tendsto_const
  1483   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
  1484   Lim_neg ~> tendsto_minus
  1485   Lim_add ~> tendsto_add
  1486   Lim_sub ~> tendsto_diff
  1487   Lim_mul ~> tendsto_scaleR
  1488   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
  1489   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
  1490   Lim_linear ~> bounded_linear.tendsto
  1491   Lim_component ~> tendsto_euclidean_component
  1492   Lim_component_cart ~> tendsto_vec_nth
  1493   Lim_inner ~> tendsto_inner [OF tendsto_const]
  1494   dot_lsum ~> inner_setsum_left
  1495   dot_rsum ~> inner_setsum_right
  1496   continuous_cmul ~> continuous_scaleR [OF continuous_const]
  1497   continuous_neg ~> continuous_minus
  1498   continuous_sub ~> continuous_diff
  1499   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
  1500   continuous_mul ~> continuous_scaleR
  1501   continuous_inv ~> continuous_inverse
  1502   continuous_at_within_inv ~> continuous_at_within_inverse
  1503   continuous_at_inv ~> continuous_at_inverse
  1504   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
  1505   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
  1506   continuous_at_component ~> continuous_component [OF continuous_at_id]
  1507   continuous_on_neg ~> continuous_on_minus
  1508   continuous_on_sub ~> continuous_on_diff
  1509   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
  1510   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
  1511   continuous_on_mul ~> continuous_on_scaleR
  1512   continuous_on_mul_real ~> continuous_on_mult
  1513   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
  1514   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
  1515   continuous_on_inverse ~> continuous_on_inv
  1516   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
  1517   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
  1518   subset_interior ~> interior_mono
  1519   subset_closure ~> closure_mono
  1520   closure_univ ~> closure_UNIV
  1521   real_arch_lt ~> reals_Archimedean2
  1522   real_arch ~> reals_Archimedean3
  1523   real_abs_norm ~> abs_norm_cancel
  1524   real_abs_sub_norm ~> norm_triangle_ineq3
  1525   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
  1526 
  1527 * Session HOL-Probability:
  1528   - Caratheodory's extension lemma is now proved for ring_of_sets.
  1529   - Infinite products of probability measures are now available.
  1530   - Sigma closure is independent, if the generator is independent
  1531   - Use extended reals instead of positive extended
  1532     reals. INCOMPATIBILITY.
  1533 
  1534 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
  1535 
  1536   expand_fun_below ~> fun_below_iff
  1537   below_fun_ext ~> fun_belowI
  1538   expand_cfun_eq ~> cfun_eq_iff
  1539   ext_cfun ~> cfun_eqI
  1540   expand_cfun_below ~> cfun_below_iff
  1541   below_cfun_ext ~> cfun_belowI
  1542   monofun_fun_fun ~> fun_belowD
  1543   monofun_fun_arg ~> monofunE
  1544   monofun_lub_fun ~> adm_monofun [THEN admD]
  1545   cont_lub_fun ~> adm_cont [THEN admD]
  1546   cont2cont_Rep_CFun ~> cont2cont_APP
  1547   cont_Rep_CFun_app ~> cont_APP_app
  1548   cont_Rep_CFun_app_app ~> cont_APP_app_app
  1549   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
  1550   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
  1551   contlub_cfun ~> lub_APP [symmetric]
  1552   contlub_LAM ~> lub_LAM [symmetric]
  1553   thelubI ~> lub_eqI
  1554   UU_I ~> bottomI
  1555   lift_distinct1 ~> lift.distinct(1)
  1556   lift_distinct2 ~> lift.distinct(2)
  1557   Def_not_UU ~> lift.distinct(2)
  1558   Def_inject ~> lift.inject
  1559   below_UU_iff ~> below_bottom_iff
  1560   eq_UU_iff ~> eq_bottom_iff
  1561 
  1562 
  1563 *** Document preparation ***
  1564 
  1565 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
  1566 isar-ref manual, both for description and actual application of the
  1567 same.
  1568 
  1569 * Antiquotation @{value} evaluates the given term and presents its
  1570 result.
  1571 
  1572 * Antiquotations: term style "isub" provides ad-hoc conversion of
  1573 variables x1, y23 into subscripted form x\<^isub>1,
  1574 y\<^isub>2\<^isub>3.
  1575 
  1576 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
  1577 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
  1578 
  1579 * Localized \isabellestyle switch can be used within blocks or groups
  1580 like this:
  1581 
  1582   \isabellestyle{it}  %preferred default
  1583   {\isabellestylett @{text "typewriter stuff"}}
  1584 
  1585 * Discontinued special treatment of hard tabulators.  Implicit
  1586 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
  1587 layouts.
  1588 
  1589 
  1590 *** ML ***
  1591 
  1592 * The inner syntax of sort/type/term/prop supports inlined YXML
  1593 representations within quoted string tokens.  By encoding logical
  1594 entities via Term_XML (in ML or Scala) concrete syntax can be
  1595 bypassed, which is particularly useful for producing bits of text
  1596 under external program control.
  1597 
  1598 * Antiquotations for ML and document preparation are managed as theory
  1599 data, which requires explicit setup.
  1600 
  1601 * Isabelle_Process.is_active allows tools to check if the official
  1602 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
  1603 (better known as Proof General).
  1604 
  1605 * Structure Proof_Context follows standard naming scheme.  Old
  1606 ProofContext is still available for some time as legacy alias.
  1607 
  1608 * Structure Timing provides various operations for timing; supersedes
  1609 former start_timing/end_timing etc.
  1610 
  1611 * Path.print is the official way to show file-system paths to users
  1612 (including quotes etc.).
  1613 
  1614 * Inner syntax: identifiers in parse trees of generic categories
  1615 "logic", "aprop", "idt" etc. carry position information (disguised as
  1616 type constraints).  Occasional INCOMPATIBILITY with non-compliant
  1617 translations that choke on unexpected type constraints.  Positions can
  1618 be stripped in ML translations via Syntax.strip_positions /
  1619 Syntax.strip_positions_ast, or via the syntax constant
  1620 "_strip_positions" within parse trees.  As last resort, positions can
  1621 be disabled via the configuration option Syntax.positions, which is
  1622 called "syntax_positions" in Isar attribute syntax.
  1623 
  1624 * Discontinued special status of various ML structures that contribute
  1625 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
  1626 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
  1627 refer directly to Ast.Constant, Lexicon.is_identifier,
  1628 Syntax_Trans.mk_binder_tr etc.
  1629 
  1630 * Typed print translation: discontinued show_sorts argument, which is
  1631 already available via context of "advanced" translation.
  1632 
  1633 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
  1634 goal states; body tactic needs to address all subgoals uniformly.
  1635 
  1636 * Slightly more special eq_list/eq_set, with shortcut involving
  1637 pointer equality (assumes that eq relation is reflexive).
  1638 
  1639 * Classical tactics use proper Proof.context instead of historic types
  1640 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
  1641 operate directly on Proof.context.  Raw type claset retains its use as
  1642 snapshot of the classical context, which can be recovered via
  1643 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
  1644 INCOMPATIBILITY, classical tactics and derived proof methods require
  1645 proper Proof.context.
  1646 
  1647 
  1648 *** System ***
  1649 
  1650 * Discontinued support for Poly/ML 5.2, which was the last version
  1651 without proper multithreading and TimeLimit implementation.
  1652 
  1653 * Discontinued old lib/scripts/polyml-platform, which has been
  1654 obsolete since Isabelle2009-2.
  1655 
  1656 * Various optional external tools are referenced more robustly and
  1657 uniformly by explicit Isabelle settings as follows:
  1658 
  1659   ISABELLE_CSDP   (formerly CSDP_EXE)
  1660   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  1661   ISABELLE_OCAML  (formerly EXEC_OCAML)
  1662   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  1663   ISABELLE_YAP    (formerly EXEC_YAP)
  1664 
  1665 Note that automated detection from the file-system or search path has
  1666 been discontinued.  INCOMPATIBILITY.
  1667 
  1668 * Scala layer provides JVM method invocation service for static
  1669 methods of type (String)String, see Invoke_Scala.method in ML.  For
  1670 example:
  1671 
  1672   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
  1673 
  1674 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
  1675 this allows to pass structured values between ML and Scala.
  1676 
  1677 * The IsabelleText fonts includes some further glyphs to support the
  1678 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
  1679 installed a local copy (which is normally *not* required) need to
  1680 delete or update it from ~~/lib/fonts/.
  1681 
  1682 
  1683 
  1684 New in Isabelle2011 (January 2011)
  1685 ----------------------------------
  1686 
  1687 *** General ***
  1688 
  1689 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
  1690 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
  1691 useful tooltips and hyperlinks produced from its static analysis.  The
  1692 bundled component provides an executable Isabelle tool that can be run
  1693 like this:
  1694 
  1695   Isabelle2011/bin/isabelle jedit
  1696 
  1697 * Significantly improved Isabelle/Isar implementation manual.
  1698 
  1699 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
  1700 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
  1701 while the default heap location within that directory lacks that extra
  1702 suffix.  This isolates multiple Isabelle installations from each
  1703 other, avoiding problems with old settings in new versions.
  1704 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
  1705 
  1706 * Source files are always encoded as UTF-8, instead of old-fashioned
  1707 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
  1708 the following package declarations:
  1709 
  1710   \usepackage[utf8]{inputenc}
  1711   \usepackage{textcomp}
  1712 
  1713 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
  1714 a Unicode character is treated as a single symbol, not a sequence of
  1715 non-ASCII bytes as before.  Since Isabelle/ML string literals may
  1716 contain symbols without further backslash escapes, Unicode can now be
  1717 used here as well.  Recall that Symbol.explode in ML provides a
  1718 consistent view on symbols, while raw explode (or String.explode)
  1719 merely give a byte-oriented representation.
  1720 
  1721 * Theory loader: source files are primarily located via the master
  1722 directory of each theory node (where the .thy file itself resides).
  1723 The global load path is still partially available as legacy feature.
  1724 Minor INCOMPATIBILITY due to subtle change in file lookup: use
  1725 explicit paths, relatively to the theory.
  1726 
  1727 * Special treatment of ML file names has been discontinued.
  1728 Historically, optional extensions .ML or .sml were added on demand --
  1729 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
  1730 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
  1731 
  1732 * Various options that affect pretty printing etc. are now properly
  1733 handled within the context via configuration options, instead of
  1734 unsynchronized references or print modes.  There are both ML Config.T
  1735 entities and Isar declaration attributes to access these.
  1736 
  1737   ML (Config.T)                 Isar (attribute)
  1738 
  1739   eta_contract                  eta_contract
  1740   show_brackets                 show_brackets
  1741   show_sorts                    show_sorts
  1742   show_types                    show_types
  1743   show_question_marks           show_question_marks
  1744   show_consts                   show_consts
  1745   show_abbrevs                  show_abbrevs
  1746 
  1747   Syntax.ast_trace              syntax_ast_trace
  1748   Syntax.ast_stat               syntax_ast_stat
  1749   Syntax.ambiguity_level        syntax_ambiguity_level
  1750 
  1751   Goal_Display.goals_limit      goals_limit
  1752   Goal_Display.show_main_goal   show_main_goal
  1753 
  1754   Method.rule_trace             rule_trace
  1755 
  1756   Thy_Output.display            thy_output_display
  1757   Thy_Output.quotes             thy_output_quotes
  1758   Thy_Output.indent             thy_output_indent
  1759   Thy_Output.source             thy_output_source
  1760   Thy_Output.break              thy_output_break
  1761 
  1762 Note that corresponding "..._default" references in ML may only be
  1763 changed globally at the ROOT session setup, but *not* within a theory.
  1764 The option "show_abbrevs" supersedes the former print mode
  1765 "no_abbrevs" with inverted meaning.
  1766 
  1767 * More systematic naming of some configuration options.
  1768 INCOMPATIBILITY.
  1769 
  1770   trace_simp  ~>  simp_trace
  1771   debug_simp  ~>  simp_debug
  1772 
  1773 * Support for real valued configuration options, using simplistic
  1774 floating-point notation that coincides with the inner syntax for
  1775 float_token.
  1776 
  1777 * Support for real valued preferences (with approximative PGIP type):
  1778 front-ends need to accept "pgint" values in float notation.
  1779 INCOMPATIBILITY.
  1780 
  1781 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
  1782 DejaVu Sans.
  1783 
  1784 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
  1785 
  1786 
  1787 *** Pure ***
  1788 
  1789 * Command 'type_synonym' (with single argument) replaces somewhat
  1790 outdated 'types', which is still available as legacy feature for some
  1791 time.
  1792 
  1793 * Command 'nonterminal' (with 'and' separated list of arguments)
  1794 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
  1795 
  1796 * Command 'notepad' replaces former 'example_proof' for
  1797 experimentation in Isar without any result.  INCOMPATIBILITY.
  1798 
  1799 * Locale interpretation commands 'interpret' and 'sublocale' accept
  1800 lists of equations to map definitions in a locale to appropriate
  1801 entities in the context of the interpretation.  The 'interpretation'
  1802 command already provided this functionality.
  1803 
  1804 * Diagnostic command 'print_dependencies' prints the locale instances
  1805 that would be activated if the specified expression was interpreted in
  1806 the current context.  Variant "print_dependencies!" assumes a context
  1807 without interpretations.
  1808 
  1809 * Diagnostic command 'print_interps' prints interpretations in proofs
  1810 in addition to interpretations in theories.
  1811 
  1812 * Discontinued obsolete 'global' and 'local' commands to manipulate
  1813 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
  1814 Sign.root_path and Sign.local_path may be applied directly where this
  1815 feature is still required for historical reasons.
  1816 
  1817 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
  1818 'definition' instead.
  1819 
  1820 * The "prems" fact, which refers to the accidental collection of
  1821 foundational premises in the context, is now explicitly marked as
  1822 legacy feature and will be discontinued soon.  Consider using "assms"
  1823 of the head statement or reference facts by explicit names.
  1824 
  1825 * Document antiquotations @{class} and @{type} print classes and type
  1826 constructors.
  1827 
  1828 * Document antiquotation @{file} checks file/directory entries within
  1829 the local file system.
  1830 
  1831 
  1832 *** HOL ***
  1833 
  1834 * Coercive subtyping: functions can be declared as coercions and type
  1835 inference will add them as necessary upon input of a term.  Theory
  1836 Complex_Main declares real :: nat => real and real :: int => real as
  1837 coercions. A coercion function f is declared like this:
  1838 
  1839   declare [[coercion f]]
  1840 
  1841 To lift coercions through type constructors (e.g. from nat => real to
  1842 nat list => real list), map functions can be declared, e.g.
  1843 
  1844   declare [[coercion_map map]]
  1845 
  1846 Currently coercion inference is activated only in theories including
  1847 real numbers, i.e. descendants of Complex_Main.  This is controlled by
  1848 the configuration option "coercion_enabled", e.g. it can be enabled in
  1849 other theories like this:
  1850 
  1851   declare [[coercion_enabled]]
  1852 
  1853 * Command 'partial_function' provides basic support for recursive
  1854 function definitions over complete partial orders.  Concrete instances
  1855 are provided for i) the option type, ii) tail recursion on arbitrary
  1856 types, and iii) the heap monad of Imperative_HOL.  See
  1857 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1858 for examples.
  1859 
  1860 * Function package: f.psimps rules are no longer implicitly declared
  1861 as [simp].  INCOMPATIBILITY.
  1862 
  1863 * Datatype package: theorems generated for executable equality (class
  1864 "eq") carry proper names and are treated as default code equations.
  1865 
  1866 * Inductive package: now offers command 'inductive_simps' to
  1867 automatically derive instantiated and simplified equations for
  1868 inductive predicates, similar to 'inductive_cases'.
  1869 
  1870 * Command 'enriched_type' allows to register properties of the
  1871 functorial structure of types.
  1872 
  1873 * Improved infrastructure for term evaluation using code generator
  1874 techniques, in particular static evaluation conversions.
  1875 
  1876 * Code generator: Scala (2.8 or higher) has been added to the target
  1877 languages.
  1878 
  1879 * Code generator: globbing constant expressions "*" and "Theory.*"
  1880 have been replaced by the more idiomatic "_" and "Theory._".
  1881 INCOMPATIBILITY.
  1882 
  1883 * Code generator: export_code without explicit file declaration prints
  1884 to standard output.  INCOMPATIBILITY.
  1885 
  1886 * Code generator: do not print function definitions for case
  1887 combinators any longer.
  1888 
  1889 * Code generator: simplification with rules determined with
  1890 src/Tools/Code/code_simp.ML and method "code_simp".
  1891 
  1892 * Code generator for records: more idiomatic representation of record
  1893 types.  Warning: records are not covered by ancient SML code
  1894 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1895 rep_datatype declaration helps to succeed then:
  1896 
  1897   record 'a foo = ...
  1898   ...
  1899   rep_datatype foo_ext ...
  1900 
  1901 * Records: logical foundation type for records does not carry a
  1902 '_type' suffix any longer (obsolete due to authentic syntax).
  1903 INCOMPATIBILITY.
  1904 
  1905 * Quickcheck now by default uses exhaustive testing instead of random
  1906 testing.  Random testing can be invoked by "quickcheck [random]",
  1907 exhaustive testing by "quickcheck [exhaustive]".
  1908 
  1909 * Quickcheck instantiates polymorphic types with small finite
  1910 datatypes by default. This enables a simple execution mechanism to
  1911 handle quantifiers and function equality over the finite datatypes.
  1912 
  1913 * Quickcheck random generator has been renamed from "code" to
  1914 "random".  INCOMPATIBILITY.
  1915 
  1916 * Quickcheck now has a configurable time limit which is set to 30
  1917 seconds by default. This can be changed by adding [timeout = n] to the
  1918 quickcheck command. The time limit for Auto Quickcheck is still set
  1919 independently.
  1920 
  1921 * Quickcheck in locales considers interpretations of that locale for
  1922 counter example search.
  1923 
  1924 * Sledgehammer:
  1925   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1926     method. See the Sledgehammer manual for details ("isabelle doc
  1927     sledgehammer").
  1928   - Renamed commands:
  1929     sledgehammer atp_info ~> sledgehammer running_provers
  1930     sledgehammer atp_kill ~> sledgehammer kill_provers
  1931     sledgehammer available_atps ~> sledgehammer available_provers
  1932     INCOMPATIBILITY.
  1933   - Renamed options:
  1934     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1935     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1936     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1937     (and "ms" and "min" are no longer supported)
  1938     INCOMPATIBILITY.
  1939 
  1940 * Nitpick:
  1941   - Renamed options:
  1942     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1943     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1944     INCOMPATIBILITY.
  1945   - Added support for partial quotient types.
  1946   - Added local versions of the "Nitpick.register_xxx" functions.
  1947   - Added "whack" option.
  1948   - Allow registration of quotient types as codatatypes.
  1949   - Improved "merge_type_vars" option to merge more types.
  1950   - Removed unsound "fast_descrs" option.
  1951   - Added custom symmetry breaking for datatypes, making it possible to reach
  1952     higher cardinalities.
  1953   - Prevent the expansion of too large definitions.
  1954 
  1955 * Proof methods "metis" and "meson" now have configuration options
  1956 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1957 to diagnose these tools. E.g.
  1958 
  1959     using [[metis_trace = true]]
  1960 
  1961 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1962 manually as command 'solve_direct'.
  1963 
  1964 * The default SMT solver Z3 must be enabled explicitly (due to
  1965 licensing issues) by setting the environment variable
  1966 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1967 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1968 changing the SMT solver is done via the configuration option
  1969 "smt_solver".
  1970 
  1971 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1972 i.e. "remote_cvc3" and "remote_z3".
  1973 
  1974 * Added basic SMT support for datatypes, records, and typedefs using
  1975 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1976 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1977 support for a similar behavior).  Minor INCOMPATIBILITY.
  1978 
  1979 * Changed SMT configuration options:
  1980   - Renamed:
  1981     z3_proofs ~> smt_oracle (with inverted meaning)
  1982     z3_trace_assms ~> smt_trace_used_facts
  1983     INCOMPATIBILITY.
  1984   - Added:
  1985     smt_verbose
  1986     smt_random_seed
  1987     smt_datatypes
  1988     smt_infer_triggers
  1989     smt_monomorph_limit
  1990     cvc3_options
  1991     remote_cvc3_options
  1992     remote_z3_options
  1993     yices_options
  1994 
  1995 * Boogie output files (.b2i files) need to be declared in the theory
  1996 header.
  1997 
  1998 * Simplification procedure "list_to_set_comprehension" rewrites list
  1999 comprehensions applied to List.set to set comprehensions.  Occasional
  2000 INCOMPATIBILITY, may be deactivated like this:
  2001 
  2002   declare [[simproc del: list_to_set_comprehension]]
  2003 
  2004 * Removed old version of primrec package.  INCOMPATIBILITY.
  2005 
  2006 * Removed simplifier congruence rule of "prod_case", as has for long
  2007 been the case with "split".  INCOMPATIBILITY.
  2008 
  2009 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  2010 
  2011 * Removed [split_format ... and ... and ...] version of
  2012 [split_format].  Potential INCOMPATIBILITY.
  2013 
  2014 * Predicate "sorted" now defined inductively, with nice induction
  2015 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  2016 
  2017 * Constant "contents" renamed to "the_elem", to free the generic name
  2018 contents for other uses.  INCOMPATIBILITY.
  2019 
  2020 * Renamed class eq and constant eq (for code generation) to class
  2021 equal and constant equal, plus renaming of related facts and various
  2022 tuning.  INCOMPATIBILITY.
  2023 
  2024 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  2025 
  2026 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  2027 INCOMPATIBILITY.
  2028 
  2029 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  2030 avoid confusion with finite sets.  INCOMPATIBILITY.
  2031 
  2032 * Abandoned locales equiv, congruent and congruent2 for equivalence
  2033 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  2034 for congruent(2)).
  2035 
  2036 * Some previously unqualified names have been qualified:
  2037 
  2038   types
  2039     bool ~> HOL.bool
  2040     nat ~> Nat.nat
  2041 
  2042   constants
  2043     Trueprop ~> HOL.Trueprop
  2044     True ~> HOL.True
  2045     False ~> HOL.False
  2046     op & ~> HOL.conj
  2047     op | ~> HOL.disj
  2048     op --> ~> HOL.implies
  2049     op = ~> HOL.eq
  2050     Not ~> HOL.Not
  2051     The ~> HOL.The
  2052     All ~> HOL.All
  2053     Ex ~> HOL.Ex
  2054     Ex1 ~> HOL.Ex1
  2055     Let ~> HOL.Let
  2056     If ~> HOL.If
  2057     Ball ~> Set.Ball
  2058     Bex ~> Set.Bex
  2059     Suc ~> Nat.Suc
  2060     Pair ~> Product_Type.Pair
  2061     fst ~> Product_Type.fst
  2062     snd ~> Product_Type.snd
  2063     curry ~> Product_Type.curry
  2064     op : ~> Set.member
  2065     Collect ~> Set.Collect
  2066 
  2067 INCOMPATIBILITY.
  2068 
  2069 * More canonical naming convention for some fundamental definitions:
  2070 
  2071     bot_bool_eq ~> bot_bool_def
  2072     top_bool_eq ~> top_bool_def
  2073     inf_bool_eq ~> inf_bool_def
  2074     sup_bool_eq ~> sup_bool_def
  2075     bot_fun_eq  ~> bot_fun_def
  2076     top_fun_eq  ~> top_fun_def
  2077     inf_fun_eq  ~> inf_fun_def
  2078     sup_fun_eq  ~> sup_fun_def
  2079 
  2080 INCOMPATIBILITY.
  2081 
  2082 * More stylized fact names:
  2083 
  2084   expand_fun_eq ~> fun_eq_iff
  2085   expand_set_eq ~> set_eq_iff
  2086   set_ext       ~> set_eqI
  2087   nat_number    ~> eval_nat_numeral
  2088 
  2089 INCOMPATIBILITY.
  2090 
  2091 * Refactoring of code-generation specific operations in theory List:
  2092 
  2093   constants
  2094     null ~> List.null
  2095 
  2096   facts
  2097     mem_iff ~> member_def
  2098     null_empty ~> null_def
  2099 
  2100 INCOMPATIBILITY.  Note that these were not supposed to be used
  2101 regularly unless for striking reasons; their main purpose was code
  2102 generation.
  2103 
  2104 Various operations from the Haskell prelude are used for generating
  2105 Haskell code.
  2106 
  2107 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  2108 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  2109 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  2110 
  2111 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  2112 "*" and "+" respectively.  INCOMPATIBILITY.
  2113 
  2114 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  2115 "Sum_Type.Plus" instead.
  2116 
  2117 * Constant "split" has been merged with constant "prod_case"; names of
  2118 ML functions, facts etc. involving split have been retained so far,
  2119 though.  INCOMPATIBILITY.
  2120 
  2121 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  2122 instead.  INCOMPATIBILITY.
  2123 
  2124 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  2125 INCOMPATIBILITY.
  2126 
  2127 * Former theory Library/Enum is now part of the HOL-Main image.
  2128 INCOMPATIBILITY: all constants of the Enum theory now have to be
  2129 referred to by its qualified name.
  2130 
  2131   enum    ~>  Enum.enum
  2132   nlists  ~>  Enum.nlists
  2133   product ~>  Enum.product
  2134 
  2135 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  2136 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  2137 INCOMPATIBILITY.
  2138 
  2139 * Theory Library/SetsAndFunctions has been split into
  2140 Library/Function_Algebras and Library/Set_Algebras; canonical names
  2141 for instance definitions for functions; various improvements.
  2142 INCOMPATIBILITY.
  2143 
  2144 * Theory Library/Multiset provides stable quicksort implementation of
  2145 sort_key.
  2146 
  2147 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  2148 INCOMPATIBILITY.
  2149 
  2150 * Session Multivariate_Analysis: introduced a type class for euclidean
  2151 space.  Most theorems are now stated in terms of euclidean spaces
  2152 instead of finite cartesian products.
  2153 
  2154   types
  2155     real ^ 'n ~>  'a::real_vector
  2156               ~>  'a::euclidean_space
  2157               ~>  'a::ordered_euclidean_space
  2158         (depends on your needs)
  2159 
  2160   constants
  2161      _ $ _        ~> _ $$ _
  2162      \<chi> x. _  ~> \<chi>\<chi> x. _
  2163      CARD('n)     ~> DIM('a)
  2164 
  2165 Also note that the indices are now natural numbers and not from some
  2166 finite type. Finite cartesian products of euclidean spaces, products
  2167 of euclidean spaces the real and complex numbers are instantiated to
  2168 be euclidean_spaces.  INCOMPATIBILITY.
  2169 
  2170 * Session Probability: introduced pextreal as positive extended real
  2171 numbers.  Use pextreal as value for measures.  Introduce the
  2172 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  2173 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  2174 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  2175 
  2176 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  2177 INCOMPATIBILITY.
  2178 
  2179 * Session SPARK (with image HOL-SPARK) provides commands to load and
  2180 prove verification conditions generated by the SPARK Ada program
  2181 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  2182 
  2183 
  2184 *** HOL-Algebra ***
  2185 
  2186 * Theorems for additive ring operations (locale abelian_monoid and
  2187 descendants) are generated by interpretation from their multiplicative
  2188 counterparts.  Names (in particular theorem names) have the mandatory
  2189 qualifier 'add'.  Previous theorem names are redeclared for
  2190 compatibility.
  2191 
  2192 * Structure "int_ring" is now an abbreviation (previously a
  2193 definition).  This fits more natural with advanced interpretations.
  2194 
  2195 
  2196 *** HOLCF ***
  2197 
  2198 * The domain package now runs in definitional mode by default: The
  2199 former command 'new_domain' is now called 'domain'.  To use the domain
  2200 package in its original axiomatic mode, use 'domain (unsafe)'.
  2201 INCOMPATIBILITY.
  2202 
  2203 * The new class "domain" is now the default sort.  Class "predomain"
  2204 is an unpointed version of "domain". Theories can be updated by
  2205 replacing sort annotations as shown below.  INCOMPATIBILITY.
  2206 
  2207   'a::type ~> 'a::countable
  2208   'a::cpo  ~> 'a::predomain
  2209   'a::pcpo ~> 'a::domain
  2210 
  2211 * The old type class "rep" has been superseded by class "domain".
  2212 Accordingly, users of the definitional package must remove any
  2213 "default_sort rep" declarations.  INCOMPATIBILITY.
  2214 
  2215 * The domain package (definitional mode) now supports unpointed
  2216 predomain argument types, as long as they are marked 'lazy'. (Strict
  2217 arguments must be in class "domain".) For example, the following
  2218 domain definition now works:
  2219 
  2220   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  2221 
  2222 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  2223 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  2224 'a option, and 'a list.  Additionally, it configures fixrec and the
  2225 domain package to work with these types.  For example:
  2226 
  2227   fixrec isInl :: "('a + 'b) u -> tr"
  2228     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  2229 
  2230   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  2231 
  2232 * The "(permissive)" option of fixrec has been replaced with a
  2233 per-equation "(unchecked)" option. See
  2234 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  2235 
  2236 * The "bifinite" class no longer fixes a constant "approx"; the class
  2237 now just asserts that such a function exists.  INCOMPATIBILITY.
  2238 
  2239 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  2240 defines an embedding of type 'a defl into udom by default; instances
  2241 of "bifinite" and "domain" classes are available in
  2242 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  2243 
  2244 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  2245 
  2246 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  2247 
  2248 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  2249 
  2250 * The function "cprod_map" has been renamed to "prod_map".
  2251 INCOMPATIBILITY.
  2252 
  2253 * The monadic bind operator on each powerdomain has new binder syntax
  2254 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  2255 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  2256 
  2257 * The infix syntax for binary union on each powerdomain has changed
  2258 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  2259 syntax.  INCOMPATIBILITY.
  2260 
  2261 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  2262 still supported as an input translation.
  2263 
  2264 * Renamed some theorems (the original names are also still available).
  2265 
  2266   expand_fun_below   ~> fun_below_iff
  2267   below_fun_ext      ~> fun_belowI
  2268   expand_cfun_eq     ~> cfun_eq_iff
  2269   ext_cfun           ~> cfun_eqI
  2270   expand_cfun_below  ~> cfun_below_iff
  2271   below_cfun_ext     ~> cfun_belowI
  2272   cont2cont_Rep_CFun ~> cont2cont_APP
  2273 
  2274 * The Abs and Rep functions for various types have changed names.
  2275 Related theorem names have also changed to match. INCOMPATIBILITY.
  2276 
  2277   Rep_CFun  ~> Rep_cfun
  2278   Abs_CFun  ~> Abs_cfun
  2279   Rep_Sprod ~> Rep_sprod
  2280   Abs_Sprod ~> Abs_sprod
  2281   Rep_Ssum  ~> Rep_ssum
  2282   Abs_Ssum  ~> Abs_ssum
  2283 
  2284 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  2285 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  2286 
  2287 * Various changes to bisimulation/coinduction with domain package:
  2288 
  2289   - Definitions of "bisim" constants no longer mention definedness.
  2290   - With mutual recursion, "bisim" predicate is now curried.
  2291   - With mutual recursion, each type gets a separate coind theorem.
  2292   - Variable names in bisim_def and coinduct rules have changed.
  2293 
  2294 INCOMPATIBILITY.
  2295 
  2296 * Case combinators generated by the domain package for type "foo" are
  2297 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  2298 
  2299 * Several theorems have been renamed to more accurately reflect the
  2300 names of constants and types involved.  INCOMPATIBILITY.
  2301 
  2302   thelub_const    ~> lub_const
  2303   lub_const       ~> is_lub_const
  2304   thelubI         ~> lub_eqI
  2305   is_lub_lub      ~> is_lubD2
  2306   lubI            ~> is_lub_lub
  2307   unique_lub      ~> is_lub_unique
  2308   is_ub_lub       ~> is_lub_rangeD1
  2309   lub_bin_chain   ~> is_lub_bin_chain
  2310   lub_fun         ~> is_lub_fun
  2311   thelub_fun      ~> lub_fun
  2312   thelub_cfun     ~> lub_cfun
  2313   thelub_Pair     ~> lub_Pair
  2314   lub_cprod       ~> is_lub_prod
  2315   thelub_cprod    ~> lub_prod
  2316   minimal_cprod   ~> minimal_prod
  2317   inst_cprod_pcpo ~> inst_prod_pcpo
  2318   UU_I            ~> bottomI
  2319   compact_UU      ~> compact_bottom
  2320   deflation_UU    ~> deflation_bottom
  2321   finite_deflation_UU ~> finite_deflation_bottom
  2322 
  2323 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  2324 
  2325   sq_ord_less_eq_trans ~> below_eq_trans
  2326   sq_ord_eq_less_trans ~> eq_below_trans
  2327   refl_less            ~> below_refl
  2328   trans_less           ~> below_trans
  2329   antisym_less         ~> below_antisym
  2330   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  2331   box_less             ~> box_below
  2332   rev_trans_less       ~> rev_below_trans
  2333   not_less2not_eq      ~> not_below2not_eq
  2334   less_UU_iff          ~> below_UU_iff
  2335   flat_less_iff        ~> flat_below_iff
  2336   adm_less             ~> adm_below
  2337   adm_not_less         ~> adm_not_below
  2338   adm_compact_not_less ~> adm_compact_not_below
  2339   less_fun_def         ~> below_fun_def
  2340   expand_fun_less      ~> fun_below_iff
  2341   less_fun_ext         ~> fun_belowI
  2342   less_discr_def       ~> below_discr_def
  2343   discr_less_eq        ~> discr_below_eq
  2344   less_unit_def        ~> below_unit_def
  2345   less_cprod_def       ~> below_prod_def
  2346   prod_lessI           ~> prod_belowI
  2347   Pair_less_iff        ~> Pair_below_iff
  2348   fst_less_iff         ~> fst_below_iff
  2349   snd_less_iff         ~> snd_below_iff
  2350   expand_cfun_less     ~> cfun_below_iff
  2351   less_cfun_ext        ~> cfun_belowI
  2352   injection_less       ~> injection_below
  2353   less_up_def          ~> below_up_def
  2354   not_Iup_less         ~> not_Iup_below
  2355   Iup_less             ~> Iup_below
  2356   up_less              ~> up_below
  2357   Def_inject_less_eq   ~> Def_below_Def
  2358   Def_less_is_eq       ~> Def_below_iff
  2359   spair_less_iff       ~> spair_below_iff
  2360   less_sprod           ~> below_sprod
  2361   spair_less           ~> spair_below
  2362   sfst_less_iff        ~> sfst_below_iff
  2363   ssnd_less_iff        ~> ssnd_below_iff
  2364   fix_least_less       ~> fix_least_below
  2365   dist_less_one        ~> dist_below_one
  2366   less_ONE             ~> below_ONE
  2367   ONE_less_iff         ~> ONE_below_iff
  2368   less_sinlD           ~> below_sinlD
  2369   less_sinrD           ~> below_sinrD
  2370 
  2371 
  2372 *** FOL and ZF ***
  2373 
  2374 * All constant names are now qualified internally and use proper
  2375 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  2376 
  2377 
  2378 *** ML ***
  2379 
  2380 * Antiquotation @{assert} inlines a function bool -> unit that raises
  2381 Fail if the argument is false.  Due to inlining the source position of
  2382 failed assertions is included in the error output.
  2383 
  2384 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  2385 text is in practice always evaluated with a stable theory checkpoint.
  2386 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  2387 
  2388 * Antiquotation @{theory A} refers to theory A from the ancestry of
  2389 the current context, not any accidental theory loader state as before.
  2390 Potential INCOMPATIBILITY, subtle change in semantics.
  2391 
  2392 * Syntax.pretty_priority (default 0) configures the required priority
  2393 of pretty-printed output and thus affects insertion of parentheses.
  2394 
  2395 * Syntax.default_root (default "any") configures the inner syntax
  2396 category (nonterminal symbol) for parsing of terms.
  2397 
  2398 * Former exception Library.UnequalLengths now coincides with
  2399 ListPair.UnequalLengths.
  2400 
  2401 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  2402 main functionality is provided by structure Simplifier.
  2403 
  2404 * Renamed raw "explode" function to "raw_explode" to emphasize its
  2405 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  2406 almost all situations.
  2407 
  2408 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  2409 See implementation manual for further details on exceptions in
  2410 Isabelle/ML.
  2411 
  2412 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  2413 meaning.
  2414 
  2415 * Renamed structure PureThy to Pure_Thy and moved most of its
  2416 operations to structure Global_Theory, to emphasize that this is
  2417 rarely-used global-only stuff.
  2418 
  2419 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  2420 instead (or tracing for high-volume output).
  2421 
  2422 * Configuration option show_question_marks only affects regular pretty
  2423 printing of types and terms, not raw Term.string_of_vname.
  2424 
  2425 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  2426 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  2427 @{thms} for most purposes.
  2428 
  2429 * ML structure Unsynchronized is never opened, not even in Isar
  2430 interaction mode as before.  Old Unsynchronized.set etc. have been
  2431 discontinued -- use plain := instead.  This should be *rare* anyway,
  2432 since modern tools always work via official context data, notably
  2433 configuration options.
  2434 
  2435 * Parallel and asynchronous execution requires special care concerning
  2436 interrupts.  Structure Exn provides some convenience functions that
  2437 avoid working directly with raw Interrupt.  User code must not absorb
  2438 interrupts -- intermediate handling (for cleanup etc.) needs to be
  2439 followed by re-raising of the original exception.  Another common
  2440 source of mistakes are "handle _" patterns, which make the meaning of
  2441 the program subject to physical effects of the environment.
  2442 
  2443 
  2444 
  2445 New in Isabelle2009-2 (June 2010)
  2446 ---------------------------------
  2447 
  2448 *** General ***
  2449 
  2450 * Authentic syntax for *all* logical entities (type classes, type
  2451 constructors, term constants): provides simple and robust
  2452 correspondence between formal entities and concrete syntax.  Within
  2453 the parse tree / AST representations, "constants" are decorated by
  2454 their category (class, type, const) and spelled out explicitly with
  2455 their full internal name.
  2456 
  2457 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  2458 and translations (translation rules and translation functions in ML).
  2459 Some hints on upgrading:
  2460 
  2461   - Many existing uses of 'syntax' and 'translations' can be replaced
  2462     by more modern 'type_notation', 'notation' and 'abbreviation',
  2463     which are independent of this issue.
  2464 
  2465   - 'translations' require markup within the AST; the term syntax
  2466     provides the following special forms:
  2467 
  2468       CONST c   -- produces syntax version of constant c from context
  2469       XCONST c  -- literally c, checked as constant from context
  2470       c         -- literally c, if declared by 'syntax'
  2471 
  2472     Plain identifiers are treated as AST variables -- occasionally the
  2473     system indicates accidental variables via the error "rhs contains
  2474     extra variables".
  2475 
  2476     Type classes and type constructors are marked according to their
  2477     concrete syntax.  Some old translations rules need to be written
  2478     for the "type" category, using type constructor application
  2479     instead of pseudo-term application of the default category
  2480     "logic".
  2481 
  2482   - 'parse_translation' etc. in ML may use the following
  2483     antiquotations:
  2484 
  2485       @{class_syntax c}   -- type class c within parse tree / AST
  2486       @{term_syntax c}    -- type constructor c within parse tree / AST
  2487       @{const_syntax c}   -- ML version of "CONST c" above
  2488       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  2489 
  2490   - Literal types within 'typed_print_translations', i.e. those *not*
  2491     represented as pseudo-terms are represented verbatim.  Use @{class
  2492     c} or @{type_name c} here instead of the above syntax
  2493     antiquotations.
  2494 
  2495 Note that old non-authentic syntax was based on unqualified base
  2496 names, so all of the above "constant" names would coincide.  Recall
  2497 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  2498 diagnose syntax problems.
  2499 
  2500 * Type constructors admit general mixfix syntax, not just infix.
  2501 
  2502 * Concrete syntax may be attached to local entities without a proof
  2503 body, too.  This works via regular mixfix annotations for 'fix',
  2504 'def', 'obtain' etc. or via the explicit 'write' command, which is
  2505 similar to the 'notation' command in theory specifications.
  2506 
  2507 * Discontinued unnamed infix syntax (legacy feature for many years) --
  2508 need to specify constant name and syntax separately.  Internal ML
  2509 datatype constructors have been renamed from InfixName to Infix etc.
  2510 Minor INCOMPATIBILITY.
  2511 
  2512 * Schematic theorem statements need to be explicitly markup as such,
  2513 via commands 'schematic_lemma', 'schematic_theorem',
  2514 'schematic_corollary'.  Thus the relevance of the proof is made
  2515 syntactically clear, which impacts performance in a parallel or
  2516 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  2517 
  2518 * Use of cumulative prems via "!" in some proof methods has been
  2519 discontinued (old legacy feature).
  2520 
  2521 * References 'trace_simp' and 'debug_simp' have been replaced by
  2522 configuration options stored in the context. Enabling tracing (the
  2523 case of debugging is similar) in proofs works via
  2524 
  2525   using [[trace_simp = true]]
  2526 
  2527 Tracing is then active for all invocations of the simplifier in
  2528 subsequent goal refinement steps. Tracing may also still be enabled or
  2529 disabled via the ProofGeneral settings menu.
  2530 
  2531 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  2532 'hide_fact' replace the former 'hide' KIND command.  Minor
  2533 INCOMPATIBILITY.
  2534 
  2535 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  2536 more efficient than combinations with -q1 or -q2.
  2537 
  2538 
  2539 *** Pure ***
  2540 
  2541 * Proofterms record type-class reasoning explicitly, using the
  2542 "unconstrain" operation internally.  This eliminates all sort
  2543 constraints from a theorem and proof, introducing explicit
  2544 OFCLASS-premises.  On the proof term level, this operation is
  2545 automatically applied at theorem boundaries, such that closed proofs
  2546 are always free of sort constraints.  INCOMPATIBILITY for tools that
  2547 inspect proof terms.
  2548 
  2549 * Local theory specifications may depend on extra type variables that
  2550 are not present in the result type -- arguments TYPE('a) :: 'a itself
  2551 are added internally.  For example:
  2552 
  2553   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  2554 
  2555 * Predicates of locales introduced by classes carry a mandatory
  2556 "class" prefix.  INCOMPATIBILITY.
  2557 
  2558 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  2559 
  2560 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  2561 'class' instead.
  2562 
  2563 * Command 'code_reflect' allows to incorporate generated ML code into
  2564 runtime environment; replaces immature code_datatype antiquotation.
  2565 INCOMPATIBILITY.
  2566 
  2567 * Code generator: simple concept for abstract datatypes obeying
  2568 invariants.
  2569 
  2570 * Code generator: details of internal data cache have no impact on the
  2571 user space functionality any longer.
  2572 
  2573 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  2574 subgoals.  This is more appropriate for interpretations with 'where'.
  2575 INCOMPATIBILITY.
  2576 
  2577 * Command 'example_proof' opens an empty proof body.  This allows to
  2578 experiment with Isar, without producing any persistent result.
  2579 
  2580 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  2581 within a local theory context, with explicit checking of the
  2582 constructors involved (in contrast to the raw 'syntax' versions).
  2583 
  2584 * Commands 'types' and 'typedecl' now work within a local theory
  2585 context -- without introducing dependencies on parameters or
  2586 assumptions, which is not possible in Isabelle/Pure.
  2587 
  2588 * Command 'defaultsort' has been renamed to 'default_sort', it works
  2589 within a local theory context.  Minor INCOMPATIBILITY.
  2590 
  2591 
  2592 *** HOL ***
  2593 
  2594 * Command 'typedef' now works within a local theory context -- without
  2595 introducing dependencies on parameters or assumptions, which is not
  2596 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  2597 contain multiple interpretations of local typedefs (with different
  2598 non-emptiness proofs), even in a global theory context.
  2599 
  2600 * New package for quotient types.  Commands 'quotient_type' and
  2601 'quotient_definition' may be used for defining types and constants by
  2602 quotient constructions.  An example is the type of integers created by
  2603 quotienting pairs of natural numbers:
  2604 
  2605   fun
  2606     intrel :: "(nat * nat) => (nat * nat) => bool"
  2607   where
  2608     "intrel (x, y) (u, v) = (x + v = u + y)"
  2609 
  2610   quotient_type int = "nat * nat" / intrel
  2611     by (auto simp add: equivp_def expand_fun_eq)
  2612 
  2613   quotient_definition
  2614     "0::int" is "(0::nat, 0::nat)"
  2615 
  2616 The method "lifting" can be used to lift of theorems from the
  2617 underlying "raw" type to the quotient type.  The example
  2618 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  2619 construction and provides a reasoning infrastructure for finite sets.
  2620 
  2621 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  2622 clash with new theory Quotient in Main HOL.
  2623 
  2624 * Moved the SMT binding into the main HOL session, eliminating
  2625 separate HOL-SMT session.
  2626 
  2627 * List membership infix mem operation is only an input abbreviation.
  2628 INCOMPATIBILITY.
  2629 
  2630 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  2631 for future developements; former Library/Word.thy is still present in
  2632 the AFP entry RSAPPS.
  2633 
  2634 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  2635 longer shadowed.  INCOMPATIBILITY.
  2636 
  2637 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  2638 INCOMPATIBILITY.
  2639 
  2640 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  2641 INCOMPATIBILITY.
  2642 
  2643 * Dropped normalizing_semiring etc; use the facts in semiring classes
  2644 instead.  INCOMPATIBILITY.
  2645 
  2646 * Dropped several real-specific versions of lemmas about floor and
  2647 ceiling; use the generic lemmas from theory "Archimedean_Field"
  2648 instead.  INCOMPATIBILITY.
  2649 
  2650   floor_number_of_eq         ~> floor_number_of
  2651   le_floor_eq_number_of      ~> number_of_le_floor
  2652   le_floor_eq_zero           ~> zero_le_floor
  2653   le_floor_eq_one            ~> one_le_floor
  2654   floor_less_eq_number_of    ~> floor_less_number_of
  2655   floor_less_eq_zero         ~> floor_less_zero
  2656   floor_less_eq_one          ~> floor_less_one
  2657   less_floor_eq_number_of    ~> number_of_less_floor
  2658   less_floor_eq_zero         ~> zero_less_floor
  2659   less_floor_eq_one          ~> one_less_floor
  2660   floor_le_eq_number_of      ~> floor_le_number_of
  2661   floor_le_eq_zero           ~> floor_le_zero
  2662   floor_le_eq_one            ~> floor_le_one
  2663   floor_subtract_number_of   ~> floor_diff_number_of
  2664   floor_subtract_one         ~> floor_diff_one
  2665   ceiling_number_of_eq       ~> ceiling_number_of
  2666   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  2667   ceiling_le_zero_eq         ~> ceiling_le_zero
  2668   ceiling_le_eq_one          ~> ceiling_le_one
  2669   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  2670   less_ceiling_eq_zero       ~> zero_less_ceiling
  2671   less_ceiling_eq_one        ~> one_less_ceiling
  2672   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  2673   ceiling_less_eq_zero       ~> ceiling_less_zero
  2674   ceiling_less_eq_one        ~> ceiling_less_one
  2675   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  2676   le_ceiling_eq_zero         ~> zero_le_ceiling
  2677   le_ceiling_eq_one          ~> one_le_ceiling
  2678   ceiling_subtract_number_of ~> ceiling_diff_number_of
  2679   ceiling_subtract_one       ~> ceiling_diff_one
  2680 
  2681 * Theory "Finite_Set": various folding_XXX locales facilitate the
  2682 application of the various fold combinators on finite sets.
  2683 
  2684 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  2685 provides abstract red-black tree type which is backed by "RBT_Impl" as
  2686 implementation.  INCOMPATIBILTY.
  2687 
  2688 * Theory Library/Coinductive_List has been removed -- superseded by
  2689 AFP/thys/Coinductive.
  2690 
  2691 * Theory PReal, including the type "preal" and related operations, has
  2692 been removed.  INCOMPATIBILITY.
  2693 
  2694 * Real: new development using Cauchy Sequences.
  2695 
  2696 * Split off theory "Big_Operators" containing setsum, setprod,
  2697 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  2698 
  2699 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  2700 "Int" etc.  INCOMPATIBILITY.
  2701 
  2702 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  2703 
  2704 * New set of rules "ac_simps" provides combined assoc / commute
  2705 rewrites for all interpretations of the appropriate generic locales.
  2706 
  2707 * Renamed theory "OrderedGroup" to "Groups" and split theory
  2708 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  2709 appropriate and more consistent names suitable for name prefixes
  2710 within the HOL theories.  INCOMPATIBILITY.
  2711 
  2712 * Some generic constants have been put to appropriate theories:
  2713   - less_eq, less: Orderings
  2714   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  2715   - inverse, divide: Rings
  2716 INCOMPATIBILITY.
  2717 
  2718 * More consistent naming of type classes involving orderings (and
  2719 lattices):
  2720 
  2721     lower_semilattice                   ~> semilattice_inf
  2722     upper_semilattice                   ~> semilattice_sup
  2723 
  2724     dense_linear_order                  ~> dense_linorder
  2725 
  2726     pordered_ab_group_add               ~> ordered_ab_group_add
  2727     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  2728     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  2729     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  2730     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  2731     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  2732     pordered_cancel_semiring            ~> ordered_cancel_semiring
  2733     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  2734     pordered_comm_ring                  ~> ordered_comm_ring
  2735     pordered_comm_semiring              ~> ordered_comm_semiring
  2736     pordered_ring                       ~> ordered_ring
  2737     pordered_ring_abs                   ~> ordered_ring_abs
  2738     pordered_semiring                   ~> ordered_semiring
  2739 
  2740     ordered_ab_group_add                ~> linordered_ab_group_add
  2741     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  2742     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  2743     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  2744     ordered_field                       ~> linordered_field
  2745     ordered_field_no_lb                 ~> linordered_field_no_lb
  2746     ordered_field_no_ub                 ~> linordered_field_no_ub
  2747     ordered_field_dense_linear_order    ~> dense_linordered_field
  2748     ordered_idom                        ~> linordered_idom
  2749     ordered_ring                        ~> linordered_ring
  2750     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  2751     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  2752     ordered_ring_strict                 ~> linordered_ring_strict
  2753     ordered_semidom                     ~> linordered_semidom
  2754     ordered_semiring                    ~> linordered_semiring
  2755     ordered_semiring_1                  ~> linordered_semiring_1
  2756     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  2757     ordered_semiring_strict             ~> linordered_semiring_strict
  2758 
  2759   The following slightly odd type classes have been moved to a
  2760   separate theory Library/Lattice_Algebras:
  2761 
  2762     lordered_ab_group_add               ~> lattice_ab_group_add
  2763     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  2764     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  2765     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  2766     lordered_ring                       ~> lattice_ring
  2767 
  2768 INCOMPATIBILITY.
  2769 
  2770 * Refined field classes:
  2771   - classes division_ring_inverse_zero, field_inverse_zero,
  2772     linordered_field_inverse_zero include rule inverse 0 = 0 --
  2773     subsumes former division_by_zero class;
  2774   - numerous lemmas have been ported from field to division_ring.
  2775 INCOMPATIBILITY.
  2776 
  2777 * Refined algebra theorem collections:
  2778   - dropped theorem group group_simps, use algebra_simps instead;
  2779   - dropped theorem group ring_simps, use field_simps instead;
  2780   - proper theorem collection field_simps subsumes former theorem
  2781     groups field_eq_simps and field_simps;
  2782   - dropped lemma eq_minus_self_iff which is a duplicate for
  2783     equal_neg_zero.
  2784 INCOMPATIBILITY.
  2785 
  2786 * Theory Finite_Set and List: some lemmas have been generalized from
  2787 sets to lattices:
  2788 
  2789   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  2790   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  2791   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  2792   union_Union_fold_union        ~> sup_Sup_fold_sup
  2793   Inter_fold_inter              ~> Inf_fold_inf
  2794   Union_fold_union              ~> Sup_fold_sup
  2795   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  2796   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  2797   INTER_fold_inter              ~> INFI_fold_inf
  2798   UNION_fold_union              ~> SUPR_fold_sup
  2799 
  2800 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  2801 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  2802 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  2803 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  2804 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  2805 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  2806 
  2807 * Reorganized theory Multiset: swapped notation of pointwise and
  2808 multiset order:
  2809 
  2810   - pointwise ordering is instance of class order with standard syntax
  2811     <= and <;
  2812   - multiset ordering has syntax <=# and <#; partial order properties
  2813     are provided by means of interpretation with prefix
  2814     multiset_order;
  2815   - less duplication, less historical organization of sections,
  2816     conversion from associations lists to multisets, rudimentary code
  2817     generation;
  2818   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  2819     if needed.
  2820 
  2821 Renamed:
  2822 
  2823   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  2824   multi_count_ext  ~>  multiset_ext
  2825   diff_union_inverse2  ~>  diff_union_cancelR
  2826 
  2827 INCOMPATIBILITY.
  2828 
  2829 * Theory Permutation: replaced local "remove" by List.remove1.
  2830 
  2831 * Code generation: ML and OCaml code is decorated with signatures.
  2832 
  2833 * Theory List: added transpose.
  2834 
  2835 * Library/Nat_Bijection.thy is a collection of bijective functions
  2836 between nat and other types, which supersedes the older libraries
  2837 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  2838 
  2839   Constants:
  2840   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  2841   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  2842   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  2843   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  2844   Countable.pair_encode           ~> prod_encode
  2845   NatIso.prod2nat                 ~> prod_encode
  2846   NatIso.nat2prod                 ~> prod_decode
  2847   NatIso.sum2nat                  ~> sum_encode
  2848   NatIso.nat2sum                  ~> sum_decode
  2849   NatIso.list2nat                 ~> list_encode
  2850   NatIso.nat2list                 ~> list_decode
  2851   NatIso.set2nat                  ~> set_encode
  2852   NatIso.nat2set                  ~> set_decode
  2853 
  2854   Lemmas:
  2855   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2856   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2857   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2858   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2859   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2860   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2861   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2862   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2863   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2864   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2865   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2866   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2867   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2868 
  2869 * Sledgehammer:
  2870   - Renamed ATP commands:
  2871     atp_info     ~> sledgehammer running_atps
  2872     atp_kill     ~> sledgehammer kill_atps
  2873     atp_messages ~> sledgehammer messages
  2874     atp_minimize ~> sledgehammer minimize
  2875     print_atps   ~> sledgehammer available_atps
  2876     INCOMPATIBILITY.
  2877   - Added user's manual ("isabelle doc sledgehammer").
  2878   - Added option syntax and "sledgehammer_params" to customize
  2879     Sledgehammer's behavior.  See the manual for details.
  2880   - Modified the Isar proof reconstruction code so that it produces
  2881     direct proofs rather than proofs by contradiction.  (This feature
  2882     is still experimental.)
  2883   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2884     full-typed mode.
  2885   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2886 
  2887 * Nitpick:
  2888   - Added and implemented "binary_ints" and "bits" options.
  2889   - Added "std" option and implemented support for nonstandard models.
  2890   - Added and implemented "finitize" option to improve the precision
  2891     of infinite datatypes based on a monotonicity analysis.
  2892   - Added support for quotient types.
  2893   - Added support for "specification" and "ax_specification"
  2894     constructs.
  2895   - Added support for local definitions (for "function" and
  2896     "termination" proofs).
  2897   - Added support for term postprocessors.
  2898   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2899   - Improved efficiency of "destroy_constrs" optimization.
  2900   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2901     record getters.
  2902   - Fixed soundness bug related to higher-order constructors.
  2903   - Fixed soundness bug when "full_descrs" is enabled.
  2904   - Improved precision of set constructs.
  2905   - Added "atoms" option.
  2906   - Added cache to speed up repeated Kodkod invocations on the same
  2907     problems.
  2908   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2909     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2910     "SAT4J_Light".  INCOMPATIBILITY.
  2911   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2912     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2913   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2914 
  2915 * Method "induct" now takes instantiations of the form t, where t is not
  2916   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2917   If this is not intended, t has to be enclosed in parentheses.
  2918   By default, the equalities generated by definitional instantiations
  2919   are pre-simplified, which may cause parameters of inductive cases
  2920   to disappear, or may even delete some of the inductive cases.
  2921   Use "induct (no_simp)" instead of "induct" to restore the old
  2922   behaviour. The (no_simp) option is also understood by the "cases"
  2923   and "nominal_induct" methods, which now perform pre-simplification, too.
  2924   INCOMPATIBILITY.
  2925 
  2926 
  2927 *** HOLCF ***
  2928 
  2929 * Variable names in lemmas generated by the domain package have
  2930 changed; the naming scheme is now consistent with the HOL datatype
  2931 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2932 
  2933 * The domain package no longer defines the function "foo_copy" for
  2934 recursive domain "foo".  The reach lemma is now stated directly in
  2935 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2936 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2937 
  2938 * Most definedness lemmas generated by the domain package (previously
  2939 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2940 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2941 Proofs that used definedness lemmas as intro rules may break,
  2942 potential INCOMPATIBILITY.
  2943 
  2944 * Induction and casedist rules generated by the domain package now
  2945 declare proper case_names (one called "bottom", and one named for each
  2946 constructor).  INCOMPATIBILITY.
  2947 
  2948 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2949 rules are generated for each domain, INCOMPATIBILITY.
  2950 
  2951   foo_bar.reach       ~> foo.reach  bar.reach
  2952   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2953 
  2954 * Some lemmas generated by the domain package have been renamed for
  2955 consistency with the datatype package, INCOMPATIBILITY.
  2956 
  2957   foo.ind        ~> foo.induct
  2958   foo.finite_ind ~> foo.finite_induct
  2959   foo.coind      ~> foo.coinduct
  2960   foo.casedist   ~> foo.exhaust
  2961   foo.exhaust    ~> foo.nchotomy
  2962 
  2963 * For consistency with other definition packages, the fixrec package
  2964 now generates qualified theorem names, INCOMPATIBILITY.
  2965 
  2966   foo_simps  ~> foo.simps
  2967   foo_unfold ~> foo.unfold
  2968   foo_induct ~> foo.induct
  2969 
  2970 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2971 method and internal fixrec proofs now use the default simpset instead.
  2972 INCOMPATIBILITY.
  2973 
  2974 * The "contlub" predicate has been removed.  Proof scripts should use
  2975 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2976 
  2977 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2978 
  2979 * The constants cpair, cfst, and csnd have been removed in favor of
  2980 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2981 
  2982 
  2983 *** ML ***
  2984 
  2985 * Antiquotations for basic formal entities:
  2986 
  2987     @{class NAME}         -- type class
  2988     @{class_syntax NAME}  -- syntax representation of the above
  2989 
  2990     @{type_name NAME}     -- logical type
  2991     @{type_abbrev NAME}   -- type abbreviation
  2992     @{nonterminal NAME}   -- type of concrete syntactic category
  2993     @{type_syntax NAME}   -- syntax representation of any of the above
  2994 
  2995     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2996     @{const_abbrev NAME}  -- abbreviated constant
  2997     @{const_syntax NAME}  -- syntax representation of any of the above
  2998 
  2999 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  3000 syntax constant (cf. 'syntax' command).
  3001 
  3002 * Antiquotation @{make_string} inlines a function to print arbitrary
  3003 values similar to the ML toplevel.  The result is compiler dependent
  3004 and may fall back on "?" in certain situations.
  3005 
  3006 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  3007 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  3008 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  3009 not work with the asynchronous Isar document model.
  3010 
  3011 * Configuration options now admit dynamic default values, depending on
  3012 the context or even global references.
  3013 
  3014 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  3015 uses an efficient external library if available (for Poly/ML).
  3016 
  3017 * Renamed some important ML structures, while keeping the old names
  3018 for some time as aliases within the structure Legacy:
  3019 
  3020   OuterKeyword  ~>  Keyword
  3021   OuterLex      ~>  Token
  3022   OuterParse    ~>  Parse
  3023   OuterSyntax   ~>  Outer_Syntax
  3024   PrintMode     ~>  Print_Mode
  3025   SpecParse     ~>  Parse_Spec
  3026   ThyInfo       ~>  Thy_Info
  3027   ThyLoad       ~>  Thy_Load
  3028   ThyOutput     ~>  Thy_Output
  3029   TypeInfer     ~>  Type_Infer
  3030 
  3031 Note that "open Legacy" simplifies porting of sources, but forgetting
  3032 to remove it again will complicate porting again in the future.
  3033 
  3034 * Most operations that refer to a global context are named
  3035 accordingly, e.g. Simplifier.global_context or
  3036 ProofContext.init_global.  There are some situations where a global
  3037 context actually works, but under normal circumstances one needs to
  3038 pass the proper local context through the code!
  3039 
  3040 * Discontinued old TheoryDataFun with its copy/init operation -- data
  3041 needs to be pure.  Functor Theory_Data_PP retains the traditional
  3042 Pretty.pp argument to merge, which is absent in the standard
  3043 Theory_Data version.
  3044 
  3045 * Sorts.certify_sort and derived "cert" operations for types and terms
  3046 no longer minimize sorts.  Thus certification at the boundary of the
  3047 inference kernel becomes invariant under addition of class relations,
  3048 which is an important monotonicity principle.  Sorts are now minimized
  3049 in the syntax layer only, at the boundary between the end-user and the
  3050 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  3051 explicitly in rare situations.
  3052 
  3053 * Renamed old-style Drule.standard to Drule.export_without_context, to
  3054 emphasize that this is in no way a standard operation.
  3055 INCOMPATIBILITY.
  3056 
  3057 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  3058 usual for resolution.  Rare INCOMPATIBILITY.
  3059 
  3060 * Renamed varify/unvarify operations to varify_global/unvarify_global
  3061 to emphasize that these only work in a global situation (which is
  3062 quite rare).
  3063 
  3064 * Curried take and drop in library.ML; negative length is interpreted
  3065 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  3066 
  3067 * Proof terms: type substitutions on proof constants now use canonical
  3068 order of type variables.  INCOMPATIBILITY for tools working with proof
  3069 terms.
  3070 
  3071 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  3072 may no longer carry premises.  User-level specifications are
  3073 transformed accordingly by Thm.add_axiom/add_def.
  3074 
  3075 
  3076 *** System ***
  3077 
  3078 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  3079 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  3080 proof terms are enabled unconditionally in the new HOL-Proofs image.
  3081 
  3082 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  3083 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  3084 respectively.
  3085 
  3086 * Old lib/scripts/polyml-platform is superseded by the
  3087 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  3088 variant, even on a 64 bit machine.  The following example setting
  3089 prefers 64 bit if available:
  3090 
  3091   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  3092 
  3093 * The preliminary Isabelle/jEdit application demonstrates the emerging
  3094 Isabelle/Scala layer for advanced prover interaction and integration.
  3095 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  3096 component.
  3097 
  3098 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  3099 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  3100 similar to the default assignment of the document preparation system
  3101 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  3102 provides some operations for direct access to the font without asking
  3103 the user for manual installation.
  3104 
  3105 
  3106 
  3107 New in Isabelle2009-1 (December 2009)
  3108 -------------------------------------
  3109 
  3110 *** General ***
  3111 
  3112 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  3113 one backslash should be used, even in ML sources.
  3114 
  3115 
  3116 *** Pure ***
  3117 
  3118 * Locale interpretation propagates mixins along the locale hierarchy.
  3119 The currently only available mixins are the equations used to map
  3120 local definitions to terms of the target domain of an interpretation.
  3121 
  3122 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  3123 loc" to print all interpretations of locale "loc" in the theory.
  3124 Interpretations in proofs are not shown.
  3125 
  3126 * Thoroughly revised locales tutorial.  New section on conditional
  3127 interpretation.
  3128 
  3129 * On instantiation of classes, remaining undefined class parameters
  3130 are formally declared.  INCOMPATIBILITY.
  3131 
  3132 
  3133 *** Document preparation ***
  3134 
  3135 * New generalized style concept for printing terms: @{foo (style) ...}
  3136 instead of @{foo_style style ...}  (old form is still retained for
  3137 backward compatibility).  Styles can be also applied for
  3138 antiquotations prop, term_type and typeof.
  3139 
  3140 
  3141 *** HOL ***
  3142 
  3143 * New proof method "smt" for a combination of first-order logic with
  3144 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  3145 fixed-size bitvectors; there is also basic support for higher-order
  3146 features (esp. lambda abstractions).  It is an incomplete decision
  3147 procedure based on external SMT solvers using the oracle mechanism;
  3148 for the SMT solver Z3, this method is proof-producing.  Certificates
  3149 are provided to avoid calling the external solvers solely for
  3150 re-checking proofs.  Due to a remote SMT service there is no need for
  3151 installing SMT solvers locally.  See src/HOL/SMT.
  3152 
  3153 * New commands to load and prove verification conditions generated by
  3154 the Boogie program verifier or derived systems (e.g. the Verifying C
  3155 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  3156 
  3157 * New counterexample generator tool 'nitpick' based on the Kodkod
  3158 relational model finder.  See src/HOL/Tools/Nitpick and
  3159 src/HOL/Nitpick_Examples.
  3160 
  3161 * New commands 'code_pred' and 'values' to invoke the predicate
  3162 compiler and to enumerate values of inductive predicates.
  3163 
  3164 * A tabled implementation of the reflexive transitive closure.
  3165 
  3166 * New implementation of quickcheck uses generic code generator;
  3167 default generators are provided for all suitable HOL types, records
  3168 and datatypes.  Old quickcheck can be re-activated importing theory
  3169 Library/SML_Quickcheck.
  3170 
  3171 * New testing tool Mirabelle for automated proof tools.  Applies
  3172 several tools and tactics like sledgehammer, metis, or quickcheck, to
  3173 every proof step in a theory.  To be used in batch mode via the
  3174 "mirabelle" utility.
  3175 
  3176 * New proof method "sos" (sum of squares) for nonlinear real
  3177 arithmetic (originally due to John Harison). It requires theory
  3178 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  3179 works well in practice on quantifier-free real arithmetic with +, -,
  3180 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  3181 inequalities between polynomials.  It makes use of external
  3182 semidefinite programming solvers.  Method "sos" generates a
  3183 certificate that can be pasted into the proof thus avoiding the need
  3184 to call an external tool every time the proof is checked.  See
  3185 src/HOL/Library/Sum_Of_Squares.
  3186 
  3187 * New method "linarith" invokes existing linear arithmetic decision
  3188 procedure only.
  3189 
  3190 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  3191 
  3192 * New Sledgehammer option "Full Types" in Proof General settings menu.
  3193 Causes full type information to be output to the ATPs.  This slows
  3194 ATPs down considerably but eliminates a source of unsound "proofs"
  3195 that fail later.
  3196 
  3197 * New method "metisFT": A version of metis that uses full type
  3198 information in order to avoid failures of proof reconstruction.
  3199 
  3200 * New evaluator "approximate" approximates an real valued term using
  3201 the same method as the approximation method.
  3202 
  3203 * Method "approximate" now supports arithmetic expressions as
  3204 boundaries of intervals and implements interval splitting and Taylor
  3205 series expansion.
  3206 
  3207 * ML antiquotation @{code_datatype} inserts definition of a datatype
  3208 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  3209 
  3210 * New theory SupInf of the supremum and infimum operators for sets of
  3211 reals.
  3212 
  3213 * New theory Probability, which contains a development of measure
  3214 theory, eventually leading to Lebesgue integration and probability.
  3215 
  3216 * Extended Multivariate Analysis to include derivation and Brouwer's
  3217 fixpoint theorem.
  3218 
  3219 * Reorganization of number theory, INCOMPATIBILITY:
  3220   - new number theory development for nat and int, in theories Divides
  3221     and GCD as well as in new session Number_Theory
  3222   - some constants and facts now suffixed with _nat and _int
  3223     accordingly
  3224   - former session NumberTheory now named Old_Number_Theory, including
  3225     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  3226   - moved theory Pocklington from src/HOL/Library to
  3227     src/HOL/Old_Number_Theory
  3228 
  3229 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  3230 lcm of finite and infinite sets. It is shown that they form a complete
  3231 lattice.
  3232 
  3233 * Class semiring_div requires superclass no_zero_divisors and proof of
  3234 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  3235 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  3236 generalized to class semiring_div, subsuming former theorems
  3237 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  3238 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  3239 INCOMPATIBILITY.
  3240 
  3241 * Refinements to lattice classes and sets:
  3242   - less default intro/elim rules in locale variant, more default
  3243     intro/elim rules in class variant: more uniformity
  3244   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  3245     le_inf_iff
  3246   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  3247     sup_aci)
  3248   - renamed ACI to inf_sup_aci
  3249   - new class "boolean_algebra"
  3250   - class "complete_lattice" moved to separate theory
  3251     "Complete_Lattice"; corresponding constants (and abbreviations)
  3252     renamed and with authentic syntax:
  3253     Set.Inf ~>    Complete_Lattice.Inf
  3254     Set.Sup ~>    Complete_Lattice.Sup
  3255     Set.INFI ~>   Complete_Lattice.INFI
  3256     Set.SUPR ~>   Complete_Lattice.SUPR
  3257     Set.Inter ~>  Complete_Lattice.Inter
  3258     Set.Union ~>  Complete_Lattice.Union
  3259     Set.INTER ~>  Complete_Lattice.INTER
  3260     Set.UNION ~>  Complete_Lattice.UNION
  3261   - authentic syntax for
  3262     Set.Pow
  3263     Set.image
  3264   - mere abbreviations:
  3265     Set.empty               (for bot)
  3266     Set.UNIV                (for top)
  3267     Set.inter               (for inf, formerly Set.Int)
  3268     Set.union               (for sup, formerly Set.Un)
  3269     Complete_Lattice.Inter  (for Inf)
  3270     Complete_Lattice.Union  (for Sup)
  3271     Complete_Lattice.INTER  (for INFI)
  3272     Complete_Lattice.UNION  (for SUPR)
  3273   - object-logic definitions as far as appropriate
  3274 
  3275 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  3276 Un_subset_iff are explicitly deleted as default simp rules; then also
  3277 their lattice counterparts le_inf_iff and le_sup_iff have to be
  3278 deleted to achieve the desired effect.
  3279 
  3280 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  3281 rules by default any longer; the same applies to min_max.inf_absorb1
  3282 etc.  INCOMPATIBILITY.
  3283 
  3284 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  3285 pred_set_conv by default.  INCOMPATIBILITY.
  3286 
  3287 * Power operations on relations and functions are now one dedicated
  3288 constant "compow" with infix syntax "^^".  Power operation on
  3289 multiplicative monoids retains syntax "^" and is now defined generic
  3290 in class power.  INCOMPATIBILITY.
  3291 
  3292 * Relation composition "R O S" now has a more standard argument order:
  3293 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  3294 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  3295 break, since the O_assoc rule was not rewritten like this.  Fix using
  3296 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  3297 
  3298 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  3299 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  3300 INCOMPATIBILITY.
  3301 
  3302 * Most rules produced by inductive and datatype package have mandatory
  3303 prefixes.  INCOMPATIBILITY.
  3304 
  3305 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  3306 the attribute of the same name.  Each of the theorems in the list
  3307 DERIV_intros assumes composition with an additional function and
  3308 matches a variable to the derivative, which has to be solved by the
  3309 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  3310 of most elementary terms.  Former Maclauren.DERIV_tac and
  3311 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  3312 INCOMPATIBILITY.
  3313 
  3314 * Code generator attributes follow the usual underscore convention:
  3315     code_unfold     replaces    code unfold
  3316     code_post       replaces    code post
  3317     etc.
  3318   INCOMPATIBILITY.
  3319 
  3320 * Renamed methods:
  3321     sizechange -> size_change
  3322     induct_scheme -> induction_schema
  3323   INCOMPATIBILITY.
  3324 
  3325 * Discontinued abbreviation "arbitrary" of constant "undefined".
  3326 INCOMPATIBILITY, use "undefined" directly.
  3327 
  3328 * Renamed theorems:
  3329     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  3330     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  3331     Suc_plus1 -> Suc_eq_plus1
  3332     *anti_sym -> *antisym*
  3333     vector_less_eq_def -> vector_le_def
  3334   INCOMPATIBILITY.
  3335 
  3336 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  3337 INCOMPATIBILITY.
  3338 
  3339 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  3340 INCOMPATIBILITY.
  3341 
  3342 
  3343 *** HOLCF ***
  3344 
  3345 * Theory Representable defines a class "rep" of domains that are
  3346 representable (via an ep-pair) in the universal domain type "udom".
  3347 Instances are provided for all type constructors defined in HOLCF.
  3348 
  3349 * The 'new_domain' command is a purely definitional version of the
  3350 domain package, for representable domains.  Syntax is identical to the
  3351 old domain package.  The 'new_domain' package also supports indirect
  3352 recursion using previously-defined type constructors.  See
  3353 src/HOLCF/ex/New_Domain.thy for examples.
  3354 
  3355 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  3356 on the left-hand side of an equation, and then performs
  3357 simplification.  Rewriting is done using rules declared with the
  3358 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  3359 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  3360 
  3361 * The pattern-match compiler in 'fixrec' can now handle constructors
  3362 with HOL function types.  Pattern-match combinators for the Pair
  3363 constructor are pre-configured.
  3364 
  3365 * The 'fixrec' package now produces better fixed-point induction rules
  3366 for mutually-recursive definitions:  Induction rules have conclusions
  3367 of the form "P foo bar" instead of "P <foo, bar>".
  3368 
  3369 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  3370 been renamed to "below".  The name "below" now replaces "less" in many
  3371 theorem names.  (Legacy theorem names using "less" are still supported
  3372 as well.)
  3373 
  3374 * The 'fixrec' package now supports "bottom patterns".  Bottom
  3375 patterns can be used to generate strictness rules, or to make
  3376 functions more strict (much like the bang-patterns supported by the
  3377 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  3378 examples.
  3379 
  3380 
  3381 *** ML ***
  3382 
  3383 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  3384 errors and run-time exceptions, including detailed source positions.
  3385 
  3386 * Structure Name_Space (formerly NameSpace) now manages uniquely
  3387 identified entries, with some additional information such as source
  3388 position, logical grouping etc.
  3389 
  3390 * Theory and context data is now introduced by the simplified and
  3391 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  3392 to be pure, but the old TheoryDataFun for mutable data (with explicit
  3393 copy operation) is still available for some time.
  3394 
  3395 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  3396 provides a high-level programming interface to synchronized state
  3397 variables with atomic update.  This works via pure function
  3398 application within a critical section -- its runtime should be as
  3399 short as possible; beware of deadlocks if critical code is nested,
  3400 either directly or indirectly via other synchronized variables!
  3401 
  3402 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  3403 wraps raw ML references, explicitly indicating their non-thread-safe
  3404 behaviour.  The Isar toplevel keeps this structure open, to
  3405 accommodate Proof General as well as quick and dirty interactive
  3406 experiments with references.
  3407 
  3408 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  3409 parallel tactical reasoning.
  3410 
  3411 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  3412 are similar to SUBPROOF, but are slightly more flexible: only the
  3413 specified parts of the subgoal are imported into the context, and the
  3414 body tactic may introduce new subgoals and schematic variables.
  3415 
  3416 * Old tactical METAHYPS, which does not observe the proof context, has
  3417 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  3418 or Subgoal.FOCUS etc.
  3419 
  3420 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  3421 functors have their own ML name space there is no point to mark them
  3422 separately.)  Minor INCOMPATIBILITY.
  3423 
  3424 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  3425 
  3426 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  3427 INCOMPATIBILITY.
  3428 
  3429 * Operations of structure Skip_Proof no longer require quick_and_dirty
  3430 mode, which avoids critical setmp.
  3431 
  3432 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  3433 combinators for "args".  INCOMPATIBILITY, need to use simplified
  3434 Attrib/Method.setup introduced in Isabelle2009.
  3435 
  3436 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  3437 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  3438 last resort.  INCOMPATIBILITY.
  3439 
  3440 * Display.pretty_thm now requires a proper context (cf. former
  3441 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  3442 or even Display.pretty_thm_without_context as last resort.
  3443 INCOMPATIBILITY.
  3444 
  3445 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  3446 Syntax.pretty_typ/term directly, preferably with proper context
  3447 instead of global theory.
  3448 
  3449 
  3450 *** System ***
  3451 
  3452 * Further fine tuning of parallel proof checking, scales up to 8 cores
  3453 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  3454 usedir option -q.
  3455 
  3456 * Support for additional "Isabelle components" via etc/components, see
  3457 also the system manual.
  3458 
  3459 * The isabelle makeall tool now operates on all components with
  3460 IsaMakefile, not just hardwired "logics".
  3461 
  3462 * Removed "compress" option from isabelle-process and isabelle usedir;
  3463 this is always enabled.
  3464 
  3465 * Discontinued support for Poly/ML 4.x versions.
  3466 
  3467 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  3468 on a given logic image.  This requires the lighttpd webserver and is
  3469 currently supported on Linux only.
  3470 
  3471 
  3472 
  3473 New in Isabelle2009 (April 2009)
  3474 --------------------------------
  3475 
  3476 *** General ***
  3477 
  3478 * Simplified main Isabelle executables, with less surprises on
  3479 case-insensitive file-systems (such as Mac OS).
  3480 
  3481   - The main Isabelle tool wrapper is now called "isabelle" instead of
  3482     "isatool."
  3483 
  3484   - The former "isabelle" alias for "isabelle-process" has been
  3485     removed (should rarely occur to regular users).
  3486 
  3487   - The former "isabelle-interface" and its alias "Isabelle" have been
  3488     removed (interfaces are now regular Isabelle tools).
  3489 
  3490 Within scripts and make files, the Isabelle environment variables
  3491 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  3492 respectively.  (The latter are still available as legacy feature.)
  3493 
  3494 The old isabelle-interface wrapper could react in confusing ways if
  3495 the interface was uninstalled or changed otherwise.  Individual
  3496 interface tool configuration is now more explicit, see also the
  3497 Isabelle system manual.  In particular, Proof General is now available
  3498 via "isabelle emacs".
  3499 
  3500 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  3501 purge installed copies of Isabelle executables and re-run "isabelle
  3502 install -p ...", or use symlinks.
  3503 
  3504 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  3505 old ~/isabelle, which was slightly non-standard and apt to cause
  3506 surprises on case-insensitive file-systems (such as Mac OS).
  3507 
  3508 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  3509 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  3510 care is required when using older releases of Isabelle.  Note that
  3511 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  3512 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  3513 
  3514 * Proofs of fully specified statements are run in parallel on
  3515 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  3516 a regular 4-core machine, if the initial heap space is made reasonably
  3517 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  3518 
  3519 * The main reference manuals ("isar-ref", "implementation", and
  3520 "system") have been updated and extended.  Formally checked references
  3521 as hyperlinks are now available uniformly.
  3522 
  3523 
  3524 *** Pure ***
  3525 
  3526 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  3527 respects.  The most important changes are listed below.  See the
  3528 Tutorial on Locales ("locales" manual) for details.
  3529 
  3530 - In locale expressions, instantiation replaces renaming.  Parameters
  3531 must be declared in a for clause.  To aid compatibility with previous
  3532 parameter inheritance, in locale declarations, parameters that are not
  3533 'touched' (instantiation position "_" or omitted) are implicitly added
  3534 with their syntax at the beginning of the for clause.
  3535 
  3536 - Syntax from abbreviations and definitions in locales is available in
  3537 locale expressions and context elements.  The latter is particularly
  3538 useful in locale declarations.
  3539 
  3540 - More flexible mechanisms to qualify names generated by locale
  3541 expressions.  Qualifiers (prefixes) may be specified in locale
  3542 expressions, and can be marked as mandatory (syntax: "name!:") or
  3543 optional (syntax "name?:").  The default depends for plain "name:"
  3544 depends on the situation where a locale expression is used: in
  3545 commands 'locale' and 'sublocale' prefixes are optional, in
  3546 'interpretation' and 'interpret' prefixes are mandatory.  The old
  3547 implicit qualifiers derived from the parameter names of a locale are
  3548 no longer generated.
  3549 
  3550 - Command "sublocale l < e" replaces "interpretation l < e".  The
  3551 instantiation clause in "interpretation" and "interpret" (square
  3552 brackets) is no longer available.  Use locale expressions.
  3553 
  3554 - When converting proof scripts, mandatory qualifiers in
  3555 'interpretation' and 'interpret' should be retained by default, even
  3556 if this is an INCOMPATIBILITY compared to former behavior.  In the
  3557 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  3558 in locale expressions range over a single locale instance only.
  3559 
  3560 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  3561 In existing theorem specifications replace the includes element by the
  3562 respective context elements of the included locale, omitting those
  3563 that are already present in the theorem specification.  Multiple
  3564 assume elements of a locale should be replaced by a single one
  3565 involving the locale predicate.  In the proof body, declarations (most
  3566 notably theorems) may be regained by interpreting the respective
  3567 locales in the proof context as required (command "interpret").
  3568 
  3569 If using "includes" in replacement of a target solely because the
  3570 parameter types in the theorem are not as general as in the target,
  3571 consider declaring a new locale with additional type constraints on
  3572 the parameters (context element "constrains").
  3573 
  3574 - Discontinued "locale (open)".  INCOMPATIBILITY.
  3575 
  3576 - Locale interpretation commands no longer attempt to simplify goal.
  3577 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  3578 methods intro_locales and unfold_locales to clarify.
  3579 
  3580 - Locale interpretation commands no longer accept interpretation
  3581 attributes.  INCOMPATIBILITY.
  3582 
  3583 * Class declaration: so-called "base sort" must not be given in import
  3584 list any longer, but is inferred from the specification.  Particularly
  3585 in HOL, write
  3586 
  3587     class foo = ...
  3588 
  3589 instead of
  3590 
  3591     class foo = type + ...
  3592 
  3593 * Class target: global versions of theorems stemming do not carry a
  3594 parameter prefix any longer.  INCOMPATIBILITY.
  3595 
  3596 * Class 'instance' command no longer accepts attached definitions.
  3597 INCOMPATIBILITY, use proper 'instantiation' target instead.
  3598 
  3599 * Recovered hiding of consts, which was accidentally broken in
  3600 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  3601 makes c inaccessible; consider using ``hide (open) const c'' instead.
  3602 
  3603 * Slightly more coherent Pure syntax, with updated documentation in
  3604 isar-ref manual.  Removed locales meta_term_syntax and
  3605 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  3606 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  3607 directly in regular applications.
  3608 
  3609 * There is a new syntactic category "float_const" for signed decimal
  3610 fractions (e.g. 123.45 or -123.45).
  3611 
  3612 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  3613 interface with 'setup' command instead.
  3614 
  3615 * Command 'local_setup' is similar to 'setup', but operates on a local
  3616 theory context.
  3617 
  3618 * The 'axiomatization' command now only works within a global theory
  3619 context.  INCOMPATIBILITY.
  3620 
  3621 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  3622 hypotheses.  Sorts required in the course of reasoning need to be
  3623 covered by the constraints in the initial statement, completed by the
  3624 type instance information of the background theory.  Non-trivial sort
  3625 hypotheses, which rarely occur in practice, may be specified via
  3626 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  3627 
  3628   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  3629 
  3630 The result contains an implicit sort hypotheses as before --
  3631 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  3632 normalization.
  3633 
  3634 * Generalized Isar history, with support for linear undo, direct state
  3635 addressing etc.
  3636 
  3637 * Changed defaults for unify configuration options:
  3638 
  3639   unify_trace_bound = 50 (formerly 25)
  3640   unify_search_bound = 60 (formerly 30)
  3641 
  3642 * Different bookkeeping for code equations (INCOMPATIBILITY):
  3643 
  3644   a) On theory merge, the last set of code equations for a particular
  3645      constant is taken (in accordance with the policy applied by other
  3646      parts of the code generator framework).
  3647 
  3648   b) Code equations stemming from explicit declarations (e.g. code
  3649      attribute) gain priority over default code equations stemming
  3650      from definition, primrec, fun etc.
  3651 
  3652 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  3653 
  3654 * Unified theorem tables for both code generators.  Thus [code
  3655 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  3656 
  3657 * Command 'find_consts' searches for constants based on type and name
  3658 patterns, e.g.
  3659 
  3660     find_consts "_ => bool"
  3661 
  3662 By default, matching is against subtypes, but it may be restricted to
  3663 the whole type.  Searching by name is possible.  Multiple queries are
  3664 conjunctive and queries may be negated by prefixing them with a
  3665 hyphen:
  3666 
  3667     find_consts strict: "_ => bool" name: "Int" -"int => int"
  3668 
  3669 * New 'find_theorems' criterion "solves" matches theorems that
  3670 directly solve the current goal (modulo higher-order unification).
  3671 
  3672 * Auto solve feature for main theorem statements: whenever a new goal
  3673 is stated, "find_theorems solves" is called; any theorems that could
  3674 solve the lemma directly are listed as part of the goal state.
  3675 Cf. associated options in Proof General Isabelle settings menu,
  3676 enabled by default, with reasonable timeout for pathological cases of
  3677 higher-order unification.
  3678 
  3679 
  3680 *** Document preparation ***
  3681 
  3682 * Antiquotation @{lemma} now imitates a regular terminal proof,
  3683 demanding keyword 'by' and supporting the full method expression
  3684 syntax just like the Isar command 'by'.
  3685 
  3686 
  3687 *** HOL ***
  3688 
  3689 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  3690 points Main and Complex_Main remain as before.
  3691 
  3692 * Logic image HOL-Plain provides a minimal HOL with the most important
  3693 tools available (inductive, datatype, primrec, ...).  This facilitates
  3694 experimentation and tool development.  Note that user applications
  3695 (and library theories) should never refer to anything below theory
  3696 Main, as before.
  3697 
  3698 * Logic image HOL-Main stops at theory Main, and thus facilitates
  3699 experimentation due to shorter build times.
  3700 
  3701 * Logic image HOL-NSA contains theories of nonstandard analysis which
  3702 were previously part of former HOL-Complex.  Entry point Hyperreal
  3703 remains valid, but theories formerly using Complex_Main should now use
  3704 new entry point Hypercomplex.
  3705 
  3706 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  3707 Posix processes.  Avoids potentially expensive forking of the ML
  3708 process.  New thread-based implementation also works on non-Unix
  3709 platforms (Cygwin).  Provers are no longer hardwired, but defined
  3710 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  3711 commands are covered in the isar-ref manual.
  3712 
  3713 * Wrapper scripts for remote SystemOnTPTP service allows to use
  3714 sledgehammer without local ATP installation (Vampire etc.). Other
  3715 provers may be included via suitable ML wrappers, see also
  3716 src/HOL/ATP_Linkup.thy.
  3717 
  3718 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  3719 menu.
  3720 
  3721 * The metis method no longer fails because the theorem is too trivial
  3722 (contains the empty clause).
  3723 
  3724 * The metis method now fails in the usual manner, rather than raising
  3725 an exception, if it determines that it cannot prove the theorem.
  3726 
  3727 * Method "coherent" implements a prover for coherent logic (see also
  3728 src/Tools/coherent.ML).
  3729 
  3730 * Constants "undefined" and "default" replace "arbitrary".  Usually
  3731 "undefined" is the right choice to replace "arbitrary", though
  3732 logically there is no difference.  INCOMPATIBILITY.
  3733 
  3734 * Command "value" now integrates different evaluation mechanisms.  The
  3735 result of the first successful evaluation mechanism is printed.  In
  3736 square brackets a particular named evaluation mechanisms may be
  3737 specified (currently, [SML], [code] or [nbe]).  See further
  3738 src/HOL/ex/Eval_Examples.thy.
  3739 
  3740 * Normalization by evaluation now allows non-leftlinear equations.
  3741 Declare with attribute [code nbe].
  3742 
  3743 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  3744 as the structured Isar versions "cases" and "induct", cf. the
  3745 corresponding "cases" and "induct" attributes.  Mutual induction rules
  3746 are now presented as a list of individual projections
  3747 (e.g. foo_bar.inducts for types foo and bar); the old format with
  3748 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  3749 rare situations a different rule is selected --- notably nested tuple
  3750 elimination instead of former prod.exhaust: use explicit (case_tac t
  3751 rule: prod.exhaust) here.
  3752 
  3753 * Attributes "cases", "induct", "coinduct" support "del" option.
  3754 
  3755 * Removed fact "case_split_thm", which duplicates "case_split".
  3756 
  3757 * The option datatype has been moved to a new theory Option.  Renamed
  3758 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  3759 
  3760 * New predicate "strict_mono" classifies strict functions on partial
  3761 orders.  With strict functions on linear orders, reasoning about
  3762 (in)equalities is facilitated by theorems "strict_mono_eq",
  3763 "strict_mono_less_eq" and "strict_mono_less".
  3764 
  3765 * Some set operations are now proper qualified constants with
  3766 authentic syntax.  INCOMPATIBILITY:
  3767 
  3768     op Int ~>   Set.Int
  3769     op Un ~>    Set.Un
  3770     INTER ~>    Set.INTER
  3771     UNION ~>    Set.UNION
  3772     Inter ~>    Set.Inter
  3773     Union ~>    Set.Union
  3774     {} ~>       Set.empty
  3775     UNIV ~>     Set.UNIV
  3776 
  3777 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  3778 theory Set.
  3779 
  3780 * Auxiliary class "itself" has disappeared -- classes without any
  3781 parameter are treated as expected by the 'class' command.
  3782 
  3783 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  3784 
  3785 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  3786 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  3787 
  3788 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  3789 method "approximation".  It proves formulas on real values by using
  3790 interval arithmetic.  In the formulas are also the transcendental
  3791 functions sin, cos, tan, atan, ln, exp and the constant pi are
  3792 allowed. For examples see
  3793 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  3794 
  3795 * Theory "Reflection" now resides in HOL/Library.
  3796 
  3797 * Entry point to Word library now simply named "Word".
  3798 INCOMPATIBILITY.
  3799 
  3800 * Made source layout more coherent with logical distribution
  3801 structure:
  3802 
  3803     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  3804     src/HOL/Library/Code_Message.thy ~> src/HOL/
  3805     src/HOL/Library/GCD.thy ~> src/HOL/
  3806     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  3807     src/HOL/Library/Parity.thy ~> src/HOL/
  3808     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  3809     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  3810     src/HOL/Real/Lubs.thy ~> src/HOL/
  3811     src/HOL/Real/PReal.thy ~> src/HOL/
  3812     src/HOL/Real/Rational.thy ~> src/HOL/
  3813     src/HOL/Real/RComplete.thy ~> src/HOL/
  3814     src/HOL/Real/RealDef.thy ~> src/HOL/
  3815     src/HOL/Real/RealPow.thy ~> src/HOL/
  3816     src/HOL/Real/Real.thy ~> src/HOL/
  3817     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  3818     src/HOL/Complex/Complex.thy ~> src/HOL/
  3819     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  3820     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  3821     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  3822     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  3823     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  3824     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  3825     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  3826     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  3827     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  3828     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  3829     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  3830     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  3831     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  3832     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  3833     src/HOL/Real/Float ~> src/HOL/Library/
  3834     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  3835     src/HOL/Real/RealVector.thy ~> src/HOL/
  3836 
  3837     src/HOL/arith_data.ML ~> src/HOL/Tools
  3838     src/HOL/hologic.ML ~> src/HOL/Tools
  3839     src/HOL/simpdata.ML ~> src/HOL/Tools
  3840     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  3841     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  3842     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  3843     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  3844     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  3845     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  3846     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  3847 
  3848     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  3849     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3850     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3851     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3852     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3853     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3854 
  3855 * If methods "eval" and "evaluation" encounter a structured proof
  3856 state with !!/==>, only the conclusion is evaluated to True (if
  3857 possible), avoiding strange error messages.
  3858 
  3859 * Method "sizechange" automates termination proofs using (a
  3860 modification of) the size-change principle.  Requires SAT solver.  See
  3861 src/HOL/ex/Termination.thy for examples.
  3862 
  3863 * Simplifier: simproc for let expressions now unfolds if bound
  3864 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3865 
  3866 * Method "arith": Linear arithmetic now ignores all inequalities when
  3867 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3868 
  3869 * New attribute "arith" for facts that should always be used
  3870 automatically by arithmetic. It is intended to be used locally in
  3871 proofs, e.g.
  3872 
  3873   assumes [arith]: "x > 0"
  3874 
  3875 Global usage is discouraged because of possible performance impact.
  3876 
  3877 * New classes "top" and "bot" with corresponding operations "top" and
  3878 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3879 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3880 
  3881 * Changed definition lemma "less_fun_def" in order to provide an
  3882 instance for preorders on functions; use lemma "less_le" instead.
  3883 INCOMPATIBILITY.
  3884 
  3885 * Theory Orderings: class "wellorder" moved here, with explicit
  3886 induction rule "less_induct" as assumption.  For instantiation of
  3887 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3888 INCOMPATIBILITY.
  3889 
  3890 * Theory Orderings: added class "preorder" as superclass of "order".
  3891 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3892 etc. slightly changed.  Some theorems named order_class.* now named
  3893 preorder_class.*.
  3894 
  3895 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3896 "diag" to "Id_on".
  3897 
  3898 * Theory Finite_Set: added a new fold combinator of type
  3899 
  3900   ('a => 'b => 'b) => 'b => 'a set => 'b
  3901 
  3902 Occasionally this is more convenient than the old fold combinator
  3903 which is now defined in terms of the new one and renamed to
  3904 fold_image.
  3905 
  3906 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3907 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3908 extended with further lemmas!).  At the moment both still exist but
  3909 the former will disappear at some point.
  3910 
  3911 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3912 class recpower.  Type-specific simp rules for various recpower types
  3913 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3914 
  3915 rat_power_0    -> power_0
  3916 rat_power_Suc  -> power_Suc
  3917 realpow_0      -> power_0
  3918 realpow_Suc    -> power_Suc
  3919 complexpow_0   -> power_0
  3920 complexpow_Suc -> power_Suc
  3921 power_poly_0   -> power_0
  3922 power_poly_Suc -> power_Suc
  3923 
  3924 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3925 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3926 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3927 of lemmas from Divides has been generalized from nat to class
  3928 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3929 renames resulting from duplicate elimination:
  3930 
  3931     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3932     zero_dvd_iff ~>         dvd_0_left_iff
  3933     dvd_0 ~>                dvd_0_right
  3934     DIVISION_BY_ZERO_DIV ~> div_by_0
  3935     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3936     mult_div ~>             div_mult_self2_is_id
  3937     mult_mod ~>             mod_mult_self2_is_0
  3938 
  3939 * Theory IntDiv: removed many lemmas that are instances of class-based
  3940 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3941 rename old lemmas as follows:
  3942 
  3943 dvd_diff               -> nat_dvd_diff
  3944 dvd_zminus_iff         -> dvd_minus_iff
  3945 mod_add1_eq            -> mod_add_eq
  3946 mod_mult1_eq           -> mod_mult_right_eq
  3947 mod_mult1_eq'          -> mod_mult_left_eq
  3948 mod_mult_distrib_mod   -> mod_mult_eq
  3949 nat_mod_add_left_eq    -> mod_add_left_eq
  3950 nat_mod_add_right_eq   -> mod_add_right_eq
  3951 nat_mod_div_trivial    -> mod_div_trivial
  3952 nat_mod_mod_trivial    -> mod_mod_trivial
  3953 zdiv_zadd_self1        -> div_add_self1
  3954 zdiv_zadd_self2        -> div_add_self2
  3955 zdiv_zmult_self1       -> div_mult_self2_is_id
  3956 zdiv_zmult_self2       -> div_mult_self1_is_id
  3957 zdvd_triv_left         -> dvd_triv_left
  3958 zdvd_triv_right        -> dvd_triv_right
  3959 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3960 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3961 zmod_zadd_left_eq      -> mod_add_left_eq
  3962 zmod_zadd_right_eq     -> mod_add_right_eq
  3963 zmod_zadd_self1        -> mod_add_self1
  3964 zmod_zadd_self2        -> mod_add_self2
  3965 zmod_zadd1_eq          -> mod_add_eq
  3966 zmod_zdiff1_eq         -> mod_diff_eq
  3967 zmod_zdvd_zmod         -> mod_mod_cancel
  3968 zmod_zmod_cancel       -> mod_mod_cancel
  3969 zmod_zmult_self1       -> mod_mult_self2_is_0
  3970 zmod_zmult_self2       -> mod_mult_self1_is_0
  3971 zmod_1                 -> mod_by_1
  3972 zdiv_1                 -> div_by_1
  3973 zdvd_abs1              -> abs_dvd_iff
  3974 zdvd_abs2              -> dvd_abs_iff
  3975 zdvd_refl              -> dvd_refl
  3976 zdvd_trans             -> dvd_trans
  3977 zdvd_zadd              -> dvd_add
  3978 zdvd_zdiff             -> dvd_diff
  3979 zdvd_zminus_iff        -> dvd_minus_iff
  3980 zdvd_zminus2_iff       -> minus_dvd_iff
  3981 zdvd_zmultD            -> dvd_mult_right
  3982 zdvd_zmultD2           -> dvd_mult_left
  3983 zdvd_zmult_mono        -> mult_dvd_mono
  3984 zdvd_0_right           -> dvd_0_right
  3985 zdvd_0_left            -> dvd_0_left_iff
  3986 zdvd_1_left            -> one_dvd
  3987 zminus_dvd_iff         -> minus_dvd_iff
  3988 
  3989 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3990 
  3991 * The real numbers offer decimal input syntax: 12.34 is translated
  3992 into 1234/10^2. This translation is not reversed upon output.
  3993 
  3994 * Theory Library/Polynomial defines an abstract type 'a poly of
  3995 univariate polynomials with coefficients of type 'a.  In addition to
  3996 the standard ring operations, it also supports div and mod.  Code
  3997 generation is also supported, using list-style constructors.
  3998 
  3999 * Theory Library/Inner_Product defines a class of real_inner for real
  4000 inner product spaces, with an overloaded operation inner :: 'a => 'a
  4001 => real.  Class real_inner is a subclass of real_normed_vector from
  4002 theory RealVector.
  4003 
  4004 * Theory Library/Product_Vector provides instances for the product
  4005 type 'a * 'b of several classes from RealVector and Inner_Product.
  4006 Definitions of addition, subtraction, scalar multiplication, norms,
  4007 and inner products are included.
  4008 
  4009 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  4010 addition to the field operations, numerals and case syntax are also
  4011 supported.
  4012 
  4013 * Theory Library/Diagonalize provides constructive version of Cantor's
  4014 first diagonalization argument.
  4015 
  4016 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  4017 zlcm (for int); carried together from various gcd/lcm developements in
  4018 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  4019 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  4020 may recover tupled syntax as follows:
  4021 
  4022     hide (open) const gcd
  4023     abbreviation gcd where
  4024       "gcd == (%(a, b). GCD.gcd a b)"
  4025     notation (output)
  4026       GCD.gcd ("gcd '(_, _')")
  4027 
  4028 The same works for lcm, zgcd, zlcm.
  4029 
  4030 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  4031 instantiations for algebraic structures.  Removed some duplicate
  4032 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  4033 
  4034 * ML antiquotation @{code} takes a constant as argument and generates
  4035 corresponding code in background and inserts name of the corresponding
  4036 resulting ML value/function/datatype constructor binding in place.
  4037 All occurrences of @{code} with a single ML block are generated
  4038 simultaneously.  Provides a generic and safe interface for
  4039 instrumentalizing code generation.  See
  4040 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  4041 In future you ought to refrain from ad-hoc compiling generated SML
  4042 code on the ML toplevel.  Note that (for technical reasons) @{code}
  4043 cannot refer to constants for which user-defined serializations are
  4044 set.  Refer to the corresponding ML counterpart directly in that
  4045 cases.
  4046 
  4047 * Command 'rep_datatype': instead of theorem names the command now
  4048 takes a list of terms denoting the constructors of the type to be
  4049 represented as datatype.  The characteristic theorems have to be
  4050 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  4051 have disappeared in favour of existing ones:
  4052 
  4053     unit_induct                 ~> unit.induct
  4054     prod_induct                 ~> prod.induct
  4055     sum_induct                  ~> sum.induct
  4056     Suc_Suc_eq                  ~> nat.inject
  4057     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  4058 
  4059 
  4060 *** HOL-Algebra ***
  4061 
  4062 * New locales for orders and lattices where the equivalence relation
  4063 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  4064 locales use a record structure with field eq for the equivalence.
  4065 
  4066 * New theory of factorial domains.
  4067 
  4068 * Units_l_inv and Units_r_inv are now simp rules by default.
  4069 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  4070 and/or r_inv will now also require deletion of these lemmas.
  4071 
  4072 * Renamed the following theorems, INCOMPATIBILITY:
  4073 
  4074 UpperD ~> Upper_memD
  4075 LowerD ~> Lower_memD
  4076 least_carrier ~> least_closed
  4077 greatest_carrier ~> greatest_closed
  4078 greatest_Lower_above ~> greatest_Lower_below
  4079 one_zero ~> carrier_one_zero
  4080 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  4081 
  4082 
  4083 *** HOL-Nominal ***
  4084 
  4085 * Nominal datatypes can now contain type-variables.
  4086 
  4087 * Commands 'nominal_inductive' and 'equivariance' work with local
  4088 theory targets.
  4089 
  4090 * Nominal primrec can now works with local theory targets and its
  4091 specification syntax now conforms to the general format as seen in
  4092 'inductive' etc.
  4093 
  4094 * Method "perm_simp" honours the standard simplifier attributes
  4095 (no_asm), (no_asm_use) etc.
  4096 
  4097 * The new predicate #* is defined like freshness, except that on the
  4098 left hand side can be a set or list of atoms.
  4099 
  4100 * Experimental command 'nominal_inductive2' derives strong induction
  4101 principles for inductive definitions.  In contrast to
  4102 'nominal_inductive', which can only deal with a fixed number of
  4103 binders, it can deal with arbitrary expressions standing for sets of
  4104 atoms to be avoided.  The only inductive definition we have at the
  4105 moment that needs this generalisation is the typing rule for Lets in
  4106 the algorithm W:
  4107 
  4108  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  4109  -----------------------------------------------------------------
  4110          Gamma |- Let x be t1 in t2 : T2
  4111 
  4112 In this rule one wants to avoid all the binders that are introduced by
  4113 "close Gamma T1".  We are looking for other examples where this
  4114 feature might be useful.  Please let us know.
  4115 
  4116 
  4117 *** HOLCF ***
  4118 
  4119 * Reimplemented the simplification procedure for proving continuity
  4120 subgoals.  The new simproc is extensible; users can declare additional
  4121 continuity introduction rules with the attribute [cont2cont].
  4122 
  4123 * The continuity simproc now uses a different introduction rule for
  4124 solving continuity subgoals on terms with lambda abstractions.  In
  4125 some rare cases the new simproc may fail to solve subgoals that the
  4126 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  4127 Potential INCOMPATIBILITY.
  4128 
  4129 * Command 'fixrec': specification syntax now conforms to the general
  4130 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  4131 examples.  INCOMPATIBILITY.
  4132 
  4133 
  4134 *** ZF ***
  4135 
  4136 * Proof of Zorn's Lemma for partial orders.
  4137 
  4138 
  4139 *** ML ***
  4140 
  4141 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  4142 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  4143 depends on multithreading, so timouts will not work before Poly/ML
  4144 5.2.1!
  4145 
  4146 * High-level support for concurrent ML programming, see
  4147 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  4148 particularly convenient to organize independent functional
  4149 computations.  The concept of "synchronized variables" provides a
  4150 higher-order interface for components with shared state, avoiding the
  4151 delicate details of mutexes and condition variables.  (Requires
  4152 Poly/ML 5.2.1 or later.)
  4153 
  4154 * ML bindings produced via Isar commands are stored within the Isar
  4155 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  4156 become thread-safe and work with undo as expected (concerning
  4157 top-level bindings, not side-effects on global references).
  4158 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  4159 compiler at runtime; really global bindings need to be given outside a
  4160 theory.  (Requires Poly/ML 5.2 or later.)
  4161 
  4162 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  4163 context.  Top-level ML bindings are stored within the proof context in
  4164 a purely sequential fashion, disregarding the nested proof structure.
  4165 ML bindings introduced by 'ML_prf' are discarded at the end of the
  4166 proof.  (Requires Poly/ML 5.2 or later.)
  4167 
  4168 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  4169 and Method.setup, as well as Isar commands 'attribute_setup' and
  4170 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  4171 existing code accordingly, or use plain 'setup' together with old
  4172 Method.add_method.
  4173 
  4174 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  4175 to 'a -> thm, while results are always tagged with an authentic oracle
  4176 name.  The Isar command 'oracle' is now polymorphic, no argument type
  4177 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  4178 accordingly.  Note that extra performance may be gained by producing
  4179 the cterm carefully, avoiding slow Thm.cterm_of.
  4180 
  4181 * Simplified interface for defining document antiquotations via
  4182 ThyOutput.antiquotation, ThyOutput.output, and optionally
  4183 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  4184 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  4185 examples.
  4186 
  4187 * More systematic treatment of long names, abstract name bindings, and
  4188 name space operations.  Basic operations on qualified names have been
  4189 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  4190 Long_Name.append.  Old type bstring has been mostly replaced by
  4191 abstract type binding (see structure Binding), which supports precise
  4192 qualification by packages and local theory targets, as well as proper
  4193 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  4194 bstring values into Binding.name, or better pass through abstract
  4195 bindings everywhere.  See further src/Pure/General/long_name.ML,
  4196 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  4197 
  4198 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  4199 LocalTheory.note etc.) now refer to the *full* internal name, not the
  4200 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  4201 
  4202 * Disposed old type and term read functions (Sign.read_def_typ,
  4203 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  4204 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  4205 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  4206 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  4207 resort for legacy applications.
  4208 
  4209 * Disposed old declarations, tactics, tactic combinators that refer to
  4210 the simpset or claset of an implicit theory (such as Addsimps,
  4211 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  4212 embedded ML text, or local_simpset_of with a proper context passed as
  4213 explicit runtime argument.
  4214 
  4215 * Rules and tactics that read instantiations (read_instantiate,
  4216 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  4217 context, which is required for parsing and type-checking.  Moreover,
  4218 the variables are specified as plain indexnames, not string encodings
  4219 thereof.  INCOMPATIBILITY.
  4220 
  4221 * Generic Toplevel.add_hook interface allows to analyze the result of
  4222 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  4223 for theorem dependency output of transactions resulting in a new
  4224 theory state.
  4225 
  4226 * ML antiquotations: block-structured compilation context indicated by
  4227 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  4228 
  4229   @{binding name}                         - basic name binding
  4230   @{let ?pat = term}                      - term abbreviation (HO matching)
  4231   @{note name = fact}                     - fact abbreviation
  4232   @{thm fact}                             - singleton fact (with attributes)
  4233   @{thms fact}                            - general fact (with attributes)
  4234   @{lemma prop by method}                 - singleton goal
  4235   @{lemma prop by meth1 meth2}            - singleton goal
  4236   @{lemma prop1 ... propN by method}      - general goal
  4237   @{lemma prop1 ... propN by meth1 meth2} - general goal
  4238   @{lemma (open) ...}                     - open derivation
  4239 
  4240 
  4241 *** System ***
  4242 
  4243 * The Isabelle "emacs" tool provides a specific interface to invoke
  4244 Proof General / Emacs, with more explicit failure if that is not
  4245 installed (the old isabelle-interface script silently falls back on
  4246 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  4247 installation location of the Proof General distribution.
  4248 
  4249 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  4250 the Isabelle process into a JVM/Scala application.  See
  4251 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  4252 process wrapper has been discontinued.)
  4253 
  4254 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  4255 
  4256 * Various status messages (with exact source position information) are
  4257 emitted, if proper markup print mode is enabled.  This allows
  4258 user-interface components to provide detailed feedback on internal
  4259 prover operations.
  4260 
  4261 
  4262 
  4263 New in Isabelle2008 (June 2008)
  4264 -------------------------------
  4265 
  4266 *** General ***
  4267 
  4268 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  4269 and updated, with formally checked references as hyperlinks.
  4270 
  4271 * Theory loader: use_thy (and similar operations) no longer set the
  4272 implicit ML context, which was occasionally hard to predict and in
  4273 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  4274 provides a proper context already.
  4275 
  4276 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4277 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  4278 'use' within a theory file will do the job.
  4279 
  4280 * Name space merge now observes canonical order, i.e. the second space
  4281 is inserted into the first one, while existing entries in the first
  4282 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  4283 swap theory imports.
  4284 
  4285 * Syntax: symbol \<chi> is now considered a letter.  Potential
  4286 INCOMPATIBILITY in identifier syntax etc.
  4287 
  4288 * Outer syntax: string tokens no longer admit escaped white space,
  4289 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  4290 white space without escapes.
  4291 
  4292 * Outer syntax: string tokens may contain arbitrary character codes
  4293 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  4294 "foo_bar".
  4295 
  4296 
  4297 *** Pure ***
  4298 
  4299 * Context-dependent token translations.  Default setup reverts locally
  4300 fixed variables, and adds hilite markup for undeclared frees.
  4301 
  4302 * Unused theorems can be found using the new command 'unused_thms'.
  4303 There are three ways of invoking it:
  4304 
  4305 (1) unused_thms
  4306      Only finds unused theorems in the current theory.
  4307 
  4308 (2) unused_thms thy_1 ... thy_n -
  4309      Finds unused theorems in the current theory and all of its ancestors,
  4310      excluding the theories thy_1 ... thy_n and all of their ancestors.
  4311 
  4312 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  4313      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  4314      their ancestors, excluding the theories thy_1 ... thy_n and all of
  4315      their ancestors.
  4316 
  4317 In order to increase the readability of the list produced by
  4318 unused_thms, theorems that have been created by a particular instance
  4319 of a theory command such as 'inductive' or 'function' are considered
  4320 to belong to the same "group", meaning that if at least one theorem in
  4321 this group is used, the other theorems in the same group are no longer
  4322 reported as unused.  Moreover, if all theorems in the group are
  4323 unused, only one theorem in the group is displayed.
  4324 
  4325 Note that proof objects have to be switched on in order for
  4326 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  4327 usually the case when using Proof General with the default settings).
  4328 
  4329 * Authentic naming of facts disallows ad-hoc overwriting of previous
  4330 theorems within the same name space.  INCOMPATIBILITY, need to remove
  4331 duplicate fact bindings, or even accidental fact duplications.  Note
  4332 that tools may maintain dynamically scoped facts systematically, using
  4333 PureThy.add_thms_dynamic.
  4334 
  4335 * Command 'hide' now allows to hide from "fact" name space as well.
  4336 
  4337 * Eliminated destructive theorem database, simpset, claset, and
  4338 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  4339 update of theories within ML code.
  4340 
  4341 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  4342 INCOMPATIBILITY, object-logics depending on former Pure require
  4343 additional setup PureThy.old_appl_syntax_setup; object-logics
  4344 depending on former CPure need to refer to Pure.
  4345 
  4346 * Commands 'use' and 'ML' are now purely functional, operating on
  4347 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  4348 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  4349 INCOMPATIBILITY.
  4350 
  4351 * Command 'setup': discontinued implicit version with ML reference.
  4352 
  4353 * Instantiation target allows for simultaneous specification of class
  4354 instance operations together with an instantiation proof.
  4355 Type-checking phase allows to refer to class operations uniformly.
  4356 See src/HOL/Complex/Complex.thy for an Isar example and
  4357 src/HOL/Library/Eval.thy for an ML example.
  4358 
  4359 * Indexing of literal facts: be more serious about including only
  4360 facts from the visible specification/proof context, but not the
  4361 background context (locale etc.).  Affects `prop` notation and method
  4362 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  4363 situations.
  4364 
  4365 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  4366 "(open)" option, which used to expose internal bound variables to the
  4367 proof text.
  4368 
  4369 * Isar statements: removed obsolete case "rule_context".
  4370 INCOMPATIBILITY, better use explicit fixes/assumes.
  4371 
  4372 * Locale proofs: default proof step now includes 'unfold_locales';
  4373 hence 'proof' without argument may be used to unfold locale
  4374 predicates.
  4375 
  4376 
  4377 *** Document preparation ***
  4378 
  4379 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  4380 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  4381 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  4382 spot); renamed link color from "darkblue" to "linkcolor" (default
  4383 value unchanged, can be redefined via \definecolor); no longer sets
  4384 "a4paper" option (unnecessary or even intrusive).
  4385 
  4386 * Antiquotation @{lemma A method} proves proposition A by the given
  4387 method (either a method name or a method name plus (optional) method
  4388 arguments in parentheses) and prints A just like @{prop A}.
  4389 
  4390 
  4391 *** HOL ***
  4392 
  4393 * New primrec package.  Specification syntax conforms in style to
  4394 definition/function/....  No separate induction rule is provided.  The
  4395 "primrec" command distinguishes old-style and new-style specifications
  4396 by syntax.  The former primrec package is now named OldPrimrecPackage.
  4397 When adjusting theories, beware: constants stemming from new-style
  4398 primrec specifications have authentic syntax.
  4399 
  4400 * Metis prover is now an order of magnitude faster, and also works
  4401 with multithreading.
  4402 
  4403 * Metis: the maximum number of clauses that can be produced from a
  4404 theorem is now given by the attribute max_clauses.  Theorems that
  4405 exceed this number are ignored, with a warning printed.
  4406 
  4407 * Sledgehammer no longer produces structured proofs by default. To
  4408 enable, declare [[sledgehammer_full = true]].  Attributes
  4409 reconstruction_modulus, reconstruction_sorts renamed
  4410 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  4411 
  4412 * Method "induct_scheme" derives user-specified induction rules
  4413 from well-founded induction and completeness of patterns. This factors
  4414 out some operations that are done internally by the function package
  4415 and makes them available separately.  See
  4416 src/HOL/ex/Induction_Scheme.thy for examples.
  4417 
  4418 * More flexible generation of measure functions for termination
  4419 proofs: Measure functions can be declared by proving a rule of the
  4420 form "is_measure f" and giving it the [measure_function] attribute.
  4421 The "is_measure" predicate is logically meaningless (always true), and
  4422 just guides the heuristic.  To find suitable measure functions, the
  4423 termination prover sets up the goal "is_measure ?f" of the appropriate
  4424 type and generates all solutions by prolog-style backwards proof using
  4425 the declared rules.
  4426 
  4427 This setup also deals with rules like 
  4428 
  4429   "is_measure f ==> is_measure (list_size f)"
  4430 
  4431 which accommodates nested datatypes that recurse through lists.
  4432 Similar rules are predeclared for products and option types.
  4433 
  4434 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  4435 
  4436   INCOMPATIBILITIES:
  4437 
  4438   - Definitions of overloaded constants on sets have to be replaced by
  4439     definitions on => and bool.
  4440 
  4441   - Some definitions of overloaded operators on sets can now be proved
  4442     using the definitions of the operators on => and bool.  Therefore,
  4443     the following theorems have been renamed:
  4444 
  4445       subset_def   -> subset_eq
  4446       psubset_def  -> psubset_eq
  4447       set_diff_def -> set_diff_eq
  4448       Compl_def    -> Compl_eq
  4449       Sup_set_def  -> Sup_set_eq
  4450       Inf_set_def  -> Inf_set_eq
  4451       sup_set_def  -> sup_set_eq
  4452       inf_set_def  -> inf_set_eq
  4453 
  4454   - Due to the incompleteness of the HO unification algorithm, some
  4455     rules such as subst may require manual instantiation, if some of
  4456     the unknowns in the rule is a set.
  4457 
  4458   - Higher order unification and forward proofs:
  4459     The proof pattern
  4460 
  4461       have "P (S::'a set)" <...>
  4462       then have "EX S. P S" ..
  4463 
  4464     no longer works (due to the incompleteness of the HO unification
  4465     algorithm) and must be replaced by the pattern
  4466 
  4467       have "EX S. P S"
  4468       proof
  4469         show "P S" <...>
  4470       qed
  4471 
  4472   - Calculational reasoning with subst (or similar rules):
  4473     The proof pattern
  4474 
  4475       have "P (S::'a set)" <...>
  4476       also have "S = T" <...>
  4477       finally have "P T" .
  4478 
  4479     no longer works (for similar reasons as the previous example) and
  4480     must be replaced by something like
  4481 
  4482       have "P (S::'a set)" <...>
  4483       moreover have "S = T" <...>
  4484       ultimately have "P T" by simp
  4485 
  4486   - Tactics or packages written in ML code:
  4487     Code performing pattern matching on types via
  4488 
  4489       Type ("set", [T]) => ...
  4490 
  4491     must be rewritten. Moreover, functions like strip_type or
  4492     binder_types no longer return the right value when applied to a
  4493     type of the form
  4494 
  4495       T1 => ... => Tn => U => bool
  4496 
  4497     rather than
  4498 
  4499       T1 => ... => Tn => U set
  4500 
  4501 * Merged theories Wellfounded_Recursion, Accessible_Part and
  4502 Wellfounded_Relations to theory Wellfounded.
  4503 
  4504 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  4505 
  4506 * Class finite no longer treats UNIV as class parameter.  Use class
  4507 enum from theory Library/Enum instead to achieve a similar effect.
  4508 INCOMPATIBILITY.
  4509 
  4510 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  4511 and "Cons".  INCOMPATIBILITY.
  4512 
  4513 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  4514 Potential INCOMPATIBILITY.
  4515 
  4516 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  4517 injective_fst_snd removed, use split_eta and prod_eqI instead.
  4518 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  4519 
  4520 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  4521 the same name in theory Orderings:
  4522 
  4523   less_trans
  4524   less_linear
  4525   le_imp_less_or_eq
  4526   le_less_trans
  4527   less_le_trans
  4528   less_not_sym
  4529   less_asym
  4530 
  4531 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  4532 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  4533 and different variable names.
  4534 
  4535 * Library/Option_ord.thy: Canonical order on option type.
  4536 
  4537 * Library/RBT.thy: Red-black trees, an efficient implementation of
  4538 finite maps.
  4539 
  4540 * Library/Countable.thy: Type class for countable types.
  4541 
  4542 * Theory Int: The representation of numerals has changed.  The infix
  4543 operator BIT and the bit datatype with constructors B0 and B1 have
  4544 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  4545 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  4546 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  4547 accordingly.
  4548 
  4549 * Theory Nat: definition of <= and < on natural numbers no longer
  4550 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  4551 le_def and less_def have disappeared.  Consider lemmas not_less
  4552 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  4553 
  4554 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  4555 (whose purpose mainly is for various fold_set functionals) have been
  4556 abandoned in favor of the existing algebraic classes
  4557 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  4558 lower_semilattice (resp. upper_semilattice) and linorder.
  4559 INCOMPATIBILITY.
  4560 
  4561 * Theory Transitive_Closure: induct and cases rules now declare proper
  4562 case_names ("base" and "step").  INCOMPATIBILITY.
  4563 
  4564 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  4565 lattices.  The form set-specific version is available as
  4566 Inductive.lfp_ordinal_induct_set.
  4567 
  4568 * Renamed theorems "power.simps" to "power_int.simps".
  4569 INCOMPATIBILITY.
  4570 
  4571 * Class semiring_div provides basic abstract properties of semirings
  4572 with division and modulo operations.  Subsumes former class dvd_mod.
  4573 
  4574 * Merged theories IntDef, Numeral and IntArith into unified theory
  4575 Int.  INCOMPATIBILITY.
  4576 
  4577 * Theory Library/Code_Index: type "index" now represents natural
  4578 numbers rather than integers.  INCOMPATIBILITY.
  4579 
  4580 * New class "uminus" with operation "uminus" (split of from class
  4581 "minus" which now only has operation "minus", binary).
  4582 INCOMPATIBILITY.
  4583 
  4584 * Constants "card", "internal_split", "option_map" now with authentic
  4585 syntax.  INCOMPATIBILITY.
  4586 
  4587 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  4588 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  4589 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  4590 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  4591 Sup_set_def, le_def, less_def, option_map_def now with object
  4592 equality.  INCOMPATIBILITY.
  4593 
  4594 * Records. Removed K_record, and replaced it by pure lambda term
  4595 %x. c. The simplifier setup is now more robust against eta expansion.
  4596 INCOMPATIBILITY: in cases explicitly referring to K_record.
  4597 
  4598 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  4599 
  4600 * Library/ListVector: new theory of arithmetic vector operations.
  4601 
  4602 * Library/Order_Relation: new theory of various orderings as sets of
  4603 pairs.  Defines preorders, partial orders, linear orders and
  4604 well-orders on sets and on types.
  4605 
  4606 
  4607 *** ZF ***
  4608 
  4609 * Renamed some theories to allow to loading both ZF and HOL in the
  4610 same session:
  4611 
  4612   Datatype  -> Datatype_ZF
  4613   Inductive -> Inductive_ZF
  4614   Int       -> Int_ZF
  4615   IntDiv    -> IntDiv_ZF
  4616   Nat       -> Nat_ZF
  4617   List      -> List_ZF
  4618   Main      -> Main_ZF
  4619 
  4620 INCOMPATIBILITY: ZF theories that import individual theories below
  4621 Main might need to be adapted.  Regular theory Main is still
  4622 available, as trivial extension of Main_ZF.
  4623 
  4624 
  4625 *** ML ***
  4626 
  4627 * ML within Isar: antiquotation @{const name} or @{const
  4628 name(typargs)} produces statically-checked Const term.
  4629 
  4630 * Functor NamedThmsFun: data is available to the user as dynamic fact
  4631 (of the same name).  Removed obsolete print command.
  4632 
  4633 * Removed obsolete "use_legacy_bindings" function.
  4634 
  4635 * The ``print mode'' is now a thread-local value derived from a global
  4636 template (the former print_mode reference), thus access becomes
  4637 non-critical.  The global print_mode reference is for session
  4638 management only; user-code should use print_mode_value,
  4639 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  4640 
  4641 * Functions system/system_out provide a robust way to invoke external
  4642 shell commands, with propagation of interrupts (requires Poly/ML
  4643 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  4644 
  4645 
  4646 *** System ***
  4647 
  4648 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  4649 in accordance with Proof General 3.7, which prefers GNU emacs.
  4650 
  4651 * isatool tty runs Isabelle process with plain tty interaction;
  4652 optional line editor may be specified via ISABELLE_LINE_EDITOR
  4653 setting, the default settings attempt to locate "ledit" and "rlwrap".
  4654 
  4655 * isatool browser now works with Cygwin as well, using general
  4656 "javapath" function defined in Isabelle process environment.
  4657 
  4658 * YXML notation provides a simple and efficient alternative to
  4659 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  4660 isatool yxml as described in the Isabelle system manual.
  4661 
  4662 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  4663 provides general wrapper for managing an Isabelle process in a robust
  4664 fashion, with ``cooked'' output from stdin/stderr.
  4665 
  4666 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  4667 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  4668 
  4669 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  4670 way of changing the user's settings is via
  4671 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  4672 script.
  4673 
  4674 * Multithreading.max_threads := 0 refers to the number of actual CPU
  4675 cores of the underlying machine, which is a good starting point for
  4676 optimal performance tuning.  The corresponding usedir option -M allows
  4677 "max" as an alias for "0".  WARNING: does not work on certain versions
  4678 of Mac OS (with Poly/ML 5.1).
  4679 
  4680 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  4681 adverse effect of Isabelle flooding interactive front-ends (notably
  4682 ProofGeneral / XEmacs).
  4683 
  4684 
  4685 
  4686 New in Isabelle2007 (November 2007)
  4687 -----------------------------------
  4688 
  4689 *** General ***
  4690 
  4691 * More uniform information about legacy features, notably a
  4692 warning/error of "Legacy feature: ...", depending on the state of the
  4693 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  4694 legacy features will disappear eventually.
  4695 
  4696 * Theory syntax: the header format ``theory A = B + C:'' has been
  4697 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  4698 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  4699 
  4700 * Theory syntax: the old non-Isar theory file format has been
  4701 discontinued altogether.  Note that ML proof scripts may still be used
  4702 with Isar theories; migration is usually quite simple with the ML
  4703 function use_legacy_bindings.  INCOMPATIBILITY.
  4704 
  4705 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  4706 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  4707 quotes.
  4708 
  4709 * Theory loader: be more serious about observing the static theory
  4710 header specifications (including optional directories), but not the
  4711 accidental file locations of previously successful loads.  The strict
  4712 update policy of former update_thy is now already performed by
  4713 use_thy, so the former has been removed; use_thys updates several
  4714 theories simultaneously, just as 'imports' within a theory header
  4715 specification, but without merging the results.  Potential
  4716 INCOMPATIBILITY: may need to refine theory headers and commands
  4717 ROOT.ML which depend on load order.
  4718 
  4719 * Theory loader: optional support for content-based file
  4720 identification, instead of the traditional scheme of full physical
  4721 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  4722 (cf. the system manual).  The new scheme allows to work with
  4723 non-finished theories in persistent session images, such that source
  4724 files may be moved later on without requiring reloads.
  4725 
  4726 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4727 file (with the same base name as the theory) are considered a legacy
  4728 feature, which will disappear eventually. Even now, the theory loader
  4729 no longer maintains dependencies on such files.
  4730 
  4731 * Syntax: the scope for resolving ambiguities via type-inference is
  4732 now limited to individual terms, instead of whole simultaneous
  4733 specifications as before. This greatly reduces the complexity of the
  4734 syntax module and improves flexibility by separating parsing and
  4735 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  4736 'fixes' etc.) are required in rare situations.
  4737 
  4738 * Syntax: constants introduced by new-style packages ('definition',
  4739 'abbreviation' etc.) are passed through the syntax module in
  4740 ``authentic mode''. This means that associated mixfix annotations
  4741 really stick to such constants, independently of potential name space
  4742 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  4743 trees are represented slightly differently, may need to adapt syntax
  4744 translations accordingly. Use CONST marker in 'translations' and
  4745 @{const_syntax} antiquotation in 'parse_translation' etc.
  4746 
  4747 * Legacy goal package: reduced interface to the bare minimum required
  4748 to keep existing proof scripts running.  Most other user-level
  4749 functions are now part of the OldGoals structure, which is *not* open
  4750 by default (consider isatool expandshort before open OldGoals).
  4751 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  4752 these tend to cause confusion about the actual goal (!) context being
  4753 used here, which is not necessarily the same as the_context().
  4754 
  4755 * Command 'find_theorems': supports "*" wild-card in "name:"
  4756 criterion; "with_dups" option.  Certain ProofGeneral versions might
  4757 support a specific search form (see ProofGeneral/CHANGES).
  4758 
  4759 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  4760 by default, which means that "prems" (and also "fixed variables") are
  4761 suppressed from proof state output.  Note that the ProofGeneral
  4762 settings mechanism allows to change and save options persistently, but
  4763 older versions of Isabelle will fail to start up if a negative prems
  4764 limit is imposed.
  4765 
  4766 * Local theory targets may be specified by non-nested blocks of
  4767 ``context/locale/class ... begin'' followed by ``end''.  The body may
  4768 contain definitions, theorems etc., including any derived mechanism
  4769 that has been implemented on top of these primitives.  This concept
  4770 generalizes the existing ``theorem (in ...)'' towards more versatility
  4771 and scalability.
  4772 
  4773 * Proof General interface: proper undo of final 'end' command;
  4774 discontinued Isabelle/classic mode (ML proof scripts).
  4775 
  4776 
  4777 *** Document preparation ***
  4778 
  4779 * Added antiquotation @{theory name} which prints the given name,
  4780 after checking that it refers to a valid ancestor theory in the
  4781 current context.
  4782 
  4783 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  4784 check the given source text as ML type/structure, printing verbatim.
  4785 
  4786 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  4787 "c args == rhs" given in the current context.  (Any number of
  4788 arguments may be given on the LHS.)
  4789 
  4790 
  4791 *** Pure ***
  4792 
  4793 * The 'class' package offers a combination of axclass and locale to
  4794 achieve Haskell-like type classes in Isabelle.  Definitions and
  4795 theorems within a class context produce both relative results (with
  4796 implicit parameters according to the locale context), and polymorphic
  4797 constants with qualified polymorphism (according to the class
  4798 context).  Within the body context of a 'class' target, a separate
  4799 syntax layer ("user space type system") takes care of converting
  4800 between global polymorphic consts and internal locale representation.
  4801 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  4802 "isatool doc classes" provides a tutorial.
  4803 
  4804 * Generic code generator framework allows to generate executable
  4805 code for ML and Haskell (including Isabelle classes).  A short usage
  4806 sketch:
  4807 
  4808     internal compilation:
  4809         export_code <list of constants (term syntax)> in SML
  4810     writing SML code to a file:
  4811         export_code <list of constants (term syntax)> in SML <filename>
  4812     writing OCaml code to a file:
  4813         export_code <list of constants (term syntax)> in OCaml <filename>
  4814     writing Haskell code to a bunch of files:
  4815         export_code <list of constants (term syntax)> in Haskell <filename>
  4816 
  4817     evaluating closed propositions to True/False using code generation:
  4818         method ``eval''
  4819 
  4820 Reasonable default setup of framework in HOL.
  4821 
  4822 Theorem attributs for selecting and transforming function equations theorems:
  4823 
  4824     [code fun]:        select a theorem as function equation for a specific constant
  4825     [code fun del]:    deselect a theorem as function equation for a specific constant
  4826     [code inline]:     select an equation theorem for unfolding (inlining) in place
  4827     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  4828 
  4829 User-defined serializations (target in {SML, OCaml, Haskell}):
  4830 
  4831     code_const <and-list of constants (term syntax)>
  4832       {(target) <and-list of const target syntax>}+
  4833 
  4834     code_type <and-list of type constructors>
  4835       {(target) <and-list of type target syntax>}+
  4836 
  4837     code_instance <and-list of instances>
  4838       {(target)}+
  4839         where instance ::= <type constructor> :: <class>
  4840 
  4841     code_class <and_list of classes>
  4842       {(target) <and-list of class target syntax>}+
  4843         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  4844 
  4845 code_instance and code_class only are effective to target Haskell.
  4846 
  4847 For example usage see src/HOL/ex/Codegenerator.thy and
  4848 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  4849 generation from Isabelle/HOL theories is available via "isatool doc
  4850 codegen".
  4851 
  4852 * Code generator: consts in 'consts_code' Isar commands are now
  4853 referred to by usual term syntax (including optional type
  4854 annotations).
  4855 
  4856 * Command 'no_translations' removes translation rules from theory
  4857 syntax.
  4858 
  4859 * Overloaded definitions are now actually checked for acyclic
  4860 dependencies.  The overloading scheme is slightly more general than
  4861 that of Haskell98, although Isabelle does not demand an exact
  4862 correspondence to type class and instance declarations.
  4863 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4864 exotic versions of overloading -- at the discretion of the user!
  4865 
  4866 Polymorphic constants are represented via type arguments, i.e. the
  4867 instantiation that matches an instance against the most general
  4868 declaration given in the signature.  For example, with the declaration
  4869 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4870 as c(nat).  Overloading is essentially simultaneous structural
  4871 recursion over such type arguments.  Incomplete specification patterns
  4872 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4873 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4874 Command 'print_theory' outputs the normalized system of recursive
  4875 equations, see section "definitions".
  4876 
  4877 * Configuration options are maintained within the theory or proof
  4878 context (with name and type bool/int/string), providing a very simple
  4879 interface to a poor-man's version of general context data.  Tools may
  4880 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4881 these values using Config.get etc.  Users may change options via an
  4882 associated attribute of the same name.  This form of context
  4883 declaration works particularly well with commands 'declare' or
  4884 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4885 very easy to avoid global references, which would not observe Isar
  4886 toplevel undo/redo and fail to work with multithreading.
  4887 
  4888 Various global ML references of Pure and HOL have been turned into
  4889 configuration options:
  4890 
  4891   Unify.search_bound		unify_search_bound
  4892   Unify.trace_bound		unify_trace_bound
  4893   Unify.trace_simp		unify_trace_simp
  4894   Unify.trace_types		unify_trace_types
  4895   Simplifier.simp_depth_limit	simp_depth_limit
  4896   Blast.depth_limit		blast_depth_limit
  4897   DatatypeProp.dtK		datatype_distinctness_limit
  4898   fast_arith_neq_limit  	fast_arith_neq_limit
  4899   fast_arith_split_limit	fast_arith_split_limit
  4900 
  4901 * Named collections of theorems may be easily installed as context
  4902 data using the functor NamedThmsFun (see also
  4903 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4904 attributes; there is also a toplevel print command.  This facility is
  4905 just a common case of general context data, which is the preferred way
  4906 for anything more complex than just a list of facts in canonical
  4907 order.
  4908 
  4909 * Isar: command 'declaration' augments a local theory by generic
  4910 declaration functions written in ML.  This enables arbitrary content
  4911 being added to the context, depending on a morphism that tells the
  4912 difference of the original declaration context wrt. the application
  4913 context encountered later on.
  4914 
  4915 * Isar: proper interfaces for simplification procedures.  Command
  4916 'simproc_setup' declares named simprocs (with match patterns, and body
  4917 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4918 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4919 
  4920 * Isar: an extra pair of brackets around attribute declarations
  4921 abbreviates a theorem reference involving an internal dummy fact,
  4922 which will be ignored later --- only the effect of the attribute on
  4923 the background context will persist.  This form of in-place
  4924 declarations is particularly useful with commands like 'declare' and
  4925 'using', for example ``have A using [[simproc a]] by simp''.
  4926 
  4927 * Isar: method "assumption" (and implicit closing of subproofs) now
  4928 takes simple non-atomic goal assumptions into account: after applying
  4929 an assumption as a rule the resulting subgoals are solved by atomic
  4930 assumption steps.  This is particularly useful to finish 'obtain'
  4931 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4932 without referring to the original premise "!!x. P x ==> thesis" in the
  4933 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4934 more permissive.
  4935 
  4936 * Isar: implicit use of prems from the Isar proof context is
  4937 considered a legacy feature.  Common applications like ``have A .''
  4938 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4939 referencing facts explicitly here improves readability and
  4940 maintainability of proof texts.
  4941 
  4942 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4943 the obtained context from the course of reasoning!  For example:
  4944 
  4945   assume "EX x y. A x & B y"   -- "any previous fact"
  4946   then guess x and y by clarify
  4947 
  4948 This technique is potentially adventurous, depending on the facts and
  4949 proof tools being involved here.
  4950 
  4951 * Isar: known facts from the proof context may be specified as literal
  4952 propositions, using ASCII back-quote syntax.  This works wherever
  4953 named facts used to be allowed so far, in proof commands, proof
  4954 methods, attributes etc.  Literal facts are retrieved from the context
  4955 according to unification of type and term parameters.  For example,
  4956 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4957 theorems in the current context, then these are valid literal facts:
  4958 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4959 
  4960 There is also a proof method "fact" which does the same composition
  4961 for explicit goal states, e.g. the following proof texts coincide with
  4962 certain special cases of literal facts:
  4963 
  4964   have "A" by fact                 ==  note `A`
  4965   have "A ==> B" by fact           ==  note `A ==> B`
  4966   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4967   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4968 
  4969 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4970 outer syntax.  Thus symbolic identifiers may be used without
  4971 additional white space in declarations like this: ``assume *: A''.
  4972 
  4973 * Isar: 'print_facts' prints all local facts of the current context,
  4974 both named and unnamed ones.
  4975 
  4976 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4977 
  4978   def x == "t" and y == "u"
  4979 
  4980 * Isar: added command 'unfolding', which is structurally similar to
  4981 'using', but affects both the goal state and facts by unfolding given
  4982 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4983 'unfolded' attribute may be replaced by first-class proof text.
  4984 
  4985 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4986 and command 'unfolding' now all support object-level equalities
  4987 (potentially conditional).  The underlying notion of rewrite rule is
  4988 analogous to the 'rule_format' attribute, but *not* that of the
  4989 Simplifier (which is usually more generous).
  4990 
  4991 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4992 premises of a theorem by n. Useful in conjunction with drule.
  4993 
  4994 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4995 method expression within a sandbox consisting of the first N
  4996 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4997 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4998 simplifies all new goals that emerge from applying rule foo to the
  4999 originally first one.
  5000 
  5001 * Isar: schematic goals are no longer restricted to higher-order
  5002 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  5003 expected.
  5004 
  5005 * Isar: the conclusion of a long theorem statement is now either
  5006 'shows' (a simultaneous conjunction, as before), or 'obtains'
  5007 (essentially a disjunction of cases with local parameters and
  5008 assumptions).  The latter allows to express general elimination rules
  5009 adequately; in this notation common elimination rules look like this:
  5010 
  5011   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  5012     assumes "EX x. P x"
  5013     obtains x where "P x"
  5014 
  5015   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  5016     assumes "A & B"
  5017     obtains A and B
  5018 
  5019   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  5020     assumes "A | B"
  5021     obtains
  5022       A
  5023     | B
  5024 
  5025 The subsequent classical rules even refer to the formal "thesis"
  5026 explicitly:
  5027 
  5028   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  5029     obtains "~ thesis"
  5030 
  5031   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  5032     obtains "thesis ==> something"
  5033 
  5034 The actual proof of an 'obtains' statement is analogous to that of the
  5035 Isar proof element 'obtain', only that there may be several cases.
  5036 Optional case names may be specified in parentheses; these will be
  5037 available both in the present proof and as annotations in the
  5038 resulting rule, for later use with the 'cases' method (cf. attribute
  5039 case_names).
  5040 
  5041 * Isar: the assumptions of a long theorem statement are available as
  5042 "assms" fact in the proof context.  This is more appropriate than the
  5043 (historical) "prems", which refers to all assumptions of the current
  5044 context, including those from the target locale, proof body etc.
  5045 
  5046 * Isar: 'print_statement' prints theorems from the current theory or
  5047 proof context in long statement form, according to the syntax of a
  5048 top-level lemma.
  5049 
  5050 * Isar: 'obtain' takes an optional case name for the local context
  5051 introduction rule (default "that").
  5052 
  5053 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  5054 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  5055 to occur.
  5056 
  5057 * Pure: syntax "CONST name" produces a fully internalized constant
  5058 according to the current context.  This is particularly useful for
  5059 syntax translations that should refer to internal constant
  5060 representations independently of name spaces.
  5061 
  5062 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  5063 instead of "FOO ". This allows multiple binder declarations to coexist
  5064 in the same context.  INCOMPATIBILITY.
  5065 
  5066 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  5067 primitive that also works in a locale context (both for constants and
  5068 fixed variables). Type declaration and internal syntactic representation
  5069 of given constants retrieved from the context. Likewise, the
  5070 'no_notation' command allows to remove given syntax annotations from the
  5071 current context.
  5072 
  5073 * Isar/locales: new derived specification elements 'axiomatization',
  5074 'definition', 'abbreviation', which support type-inference, admit
  5075 object-level specifications (equality, equivalence).  See also the
  5076 isar-ref manual.  Examples:
  5077 
  5078   axiomatization
  5079     eq  (infix "===" 50) where
  5080     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  5081 
  5082   definition "f x y = x + y + 1"
  5083   definition g where "g x = f x x"
  5084 
  5085   abbreviation
  5086     neq  (infix "=!=" 50) where
  5087     "x =!= y == ~ (x === y)"
  5088 
  5089 These specifications may be also used in a locale context.  Then the
  5090 constants being introduced depend on certain fixed parameters, and the
  5091 constant name is qualified by the locale base name.  An internal
  5092 abbreviation takes care for convenient input and output, making the
  5093 parameters implicit and using the original short name.  See also
  5094 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  5095 entities from a monomorphic theory.
  5096 
  5097 Presently, abbreviations are only available 'in' a target locale, but
  5098 not inherited by general import expressions.  Also note that
  5099 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  5100 'translations' in common applications.  The "no_abbrevs" print mode
  5101 prevents folding of abbreviations in term output.
  5102 
  5103 Concrete syntax is attached to specified constants in internal form,
  5104 independently of name spaces.  The parse tree representation is
  5105 slightly different -- use 'notation' instead of raw 'syntax', and
  5106 'translations' with explicit "CONST" markup to accommodate this.
  5107 
  5108 * Pure/Isar: unified syntax for new-style specification mechanisms
  5109 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  5110 full type inference and dummy patterns ("_").  For example:
  5111 
  5112   definition "K x _ = x"
  5113 
  5114   inductive conj for A B
  5115   where "A ==> B ==> conj A B"
  5116 
  5117 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  5118 the current context.  Print mode "no_abbrevs" prevents inversion of
  5119 abbreviations on output.
  5120 
  5121 * Isar/locales: improved parameter handling: use of locales "var" and
  5122 "struct" no longer necessary; - parameter renamings are no longer
  5123 required to be injective.  For example, this allows to define
  5124 endomorphisms as locale endom = homom mult mult h.
  5125 
  5126 * Isar/locales: changed the way locales with predicates are defined.
  5127 Instead of accumulating the specification, the imported expression is
  5128 now an interpretation.  INCOMPATIBILITY: different normal form of
  5129 locale expressions.  In particular, in interpretations of locales with
  5130 predicates, goals repesenting already interpreted fragments are not
  5131 removed automatically.  Use methods `intro_locales' and
  5132 `unfold_locales'; see below.
  5133 
  5134 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  5135 provide backward reasoning on locales predicates.  The methods are
  5136 aware of interpretations and discharge corresponding goals.
  5137 `intro_locales' is less aggressive then `unfold_locales' and does not
  5138 unfold predicates to assumptions.
  5139 
  5140 * Isar/locales: the order in which locale fragments are accumulated
  5141 has changed.  This enables to override declarations from fragments due
  5142 to interpretations -- for example, unwanted simp rules.
  5143 
  5144 * Isar/locales: interpretation in theories and proof contexts has been
  5145 extended.  One may now specify (and prove) equations, which are
  5146 unfolded in interpreted theorems.  This is useful for replacing
  5147 defined concepts (constants depending on locale parameters) by
  5148 concepts already existing in the target context.  Example:
  5149 
  5150   interpretation partial_order ["op <= :: [int, int] => bool"]
  5151     where "partial_order.less (op <=) (x::int) y = (x < y)"
  5152 
  5153 Typically, the constant `partial_order.less' is created by a
  5154 definition specification element in the context of locale
  5155 partial_order.
  5156 
  5157 * Method "induct": improved internal context management to support
  5158 local fixes and defines on-the-fly. Thus explicit meta-level
  5159 connectives !!  and ==> are rarely required anymore in inductive goals
  5160 (using object-logic connectives for this purpose has been long
  5161 obsolete anyway). Common proof patterns are explained in
  5162 src/HOL/Induct/Common_Patterns.thy, see also
  5163 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  5164 examples.
  5165 
  5166 * Method "induct": improved handling of simultaneous goals. Instead of
  5167 introducing object-level conjunction, the statement is now split into
  5168 several conclusions, while the corresponding symbolic cases are nested
  5169 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  5170 see src/HOL/Induct/Common_Patterns.thy, for example.
  5171 
  5172 * Method "induct": mutual induction rules are now specified as a list
  5173 of rule sharing the same induction cases. HOL packages usually provide
  5174 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  5175 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  5176 mutual induction rules differently, i.e. like this:
  5177 
  5178   (induct rule: foo_bar.inducts)
  5179   (induct set: foo bar)
  5180   (induct pred: foo bar)
  5181   (induct type: foo bar)
  5182 
  5183 The ML function ProjectRule.projections turns old-style rules into the
  5184 new format.
  5185 
  5186 * Method "coinduct": dual of induction, see
  5187 src/HOL/Library/Coinductive_List.thy for various examples.
  5188 
  5189 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  5190 considered a legacy feature.
  5191 
  5192 * Attribute "symmetric" produces result with standardized schematic
  5193 variables (index 0).  Potential INCOMPATIBILITY.
  5194 
  5195 * Simplifier: by default the simplifier trace only shows top level
  5196 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  5197 default. Thus there is less danger of being flooded by the trace. The
  5198 trace indicates where parts have been suppressed.
  5199   
  5200 * Provers/classical: removed obsolete classical version of elim_format
  5201 attribute; classical elim/dest rules are now treated uniformly when
  5202 manipulating the claset.
  5203 
  5204 * Provers/classical: stricter checks to ensure that supplied intro,
  5205 dest and elim rules are well-formed; dest and elim rules must have at
  5206 least one premise.
  5207 
  5208 * Provers/classical: attributes dest/elim/intro take an optional
  5209 weight argument for the rule (just as the Pure versions).  Weights are
  5210 ignored by automated tools, but determine the search order of single
  5211 rule steps.
  5212 
  5213 * Syntax: input syntax now supports dummy variable binding "%_. b",
  5214 where the body does not mention the bound variable.  Note that dummy
  5215 patterns implicitly depend on their context of bounds, which makes
  5216 "{_. _}" match any set comprehension as expected.  Potential
  5217 INCOMPATIBILITY -- parse translations need to cope with syntactic
  5218 constant "_idtdummy" in the binding position.
  5219 
  5220 * Syntax: removed obsolete syntactic constant "_K" and its associated
  5221 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  5222 for example "A -> B" => "Pi A (%_. B)".
  5223 
  5224 * Pure: 'class_deps' command visualizes the subclass relation, using
  5225 the graph browser tool.
  5226 
  5227 * Pure: 'print_theory' now suppresses certain internal declarations by
  5228 default; use '!' option for full details.
  5229 
  5230 
  5231 *** HOL ***
  5232 
  5233 * Method "metis" proves goals by applying the Metis general-purpose
  5234 resolution prover (see also http://gilith.com/software/metis/).
  5235 Examples are in the directory MetisExamples.  WARNING: the
  5236 Isabelle/HOL-Metis integration does not yet work properly with
  5237 multi-threading.
  5238   
  5239 * Command 'sledgehammer' invokes external automatic theorem provers as
  5240 background processes.  It generates calls to the "metis" method if
  5241 successful. These can be pasted into the proof.  Users do not have to
  5242 wait for the automatic provers to return.  WARNING: does not really
  5243 work with multi-threading.
  5244 
  5245 * New "auto_quickcheck" feature tests outermost goal statements for
  5246 potential counter-examples.  Controlled by ML references
  5247 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  5248 5000 milliseconds).  Fails silently if statements is outside of
  5249 executable fragment, or any other codgenerator problem occurs.
  5250 
  5251 * New constant "undefined" with axiom "undefined x = undefined".
  5252 
  5253 * Added class "HOL.eq", allowing for code generation with polymorphic
  5254 equality.
  5255 
  5256 * Some renaming of class constants due to canonical name prefixing in
  5257 the new 'class' package:
  5258 
  5259     HOL.abs ~> HOL.abs_class.abs
  5260     HOL.divide ~> HOL.divide_class.divide
  5261     0 ~> HOL.zero_class.zero
  5262     1 ~> HOL.one_class.one
  5263     op + ~> HOL.plus_class.plus
  5264     op - ~> HOL.minus_class.minus
  5265     uminus ~> HOL.minus_class.uminus
  5266     op * ~> HOL.times_class.times
  5267     op < ~> HOL.ord_class.less
  5268     op <= > HOL.ord_class.less_eq
  5269     Nat.power ~> Power.power_class.power
  5270     Nat.size ~> Nat.size_class.size
  5271     Numeral.number_of ~> Numeral.number_class.number_of
  5272     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  5273     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  5274     Orderings.min ~> Orderings.ord_class.min
  5275     Orderings.max ~> Orderings.ord_class.max
  5276     Divides.op div ~> Divides.div_class.div
  5277     Divides.op mod ~> Divides.div_class.mod
  5278     Divides.op dvd ~> Divides.div_class.dvd
  5279 
  5280 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  5281 
  5282 a) User-defined constants using any of the names "plus", "minus",
  5283 "times", "less" or "less_eq". The standard syntax translations for
  5284 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  5285 names.
  5286 
  5287 b) Variables named "plus", "minus", "times", "less", "less_eq"
  5288 INCOMPATIBILITY: use more specific names.
  5289 
  5290 c) Permutative equations (e.g. "a + b = b + a")
  5291 Since the change of names also changes the order of terms, permutative
  5292 rewrite rules may get applied in a different order. Experience shows
  5293 that this is rarely the case (only two adaptions in the whole Isabelle
  5294 distribution).  INCOMPATIBILITY: rewrite proofs
  5295 
  5296 d) ML code directly refering to constant names
  5297 This in general only affects hand-written proof tactics, simprocs and
  5298 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  5299 Consider using @{const_name} antiquotation.
  5300 
  5301 * New class "default" with associated constant "default".
  5302 
  5303 * Function "sgn" is now overloaded and available on int, real, complex
  5304 (and other numeric types), using class "sgn".  Two possible defs of
  5305 sgn are given as equational assumptions in the classes sgn_if and
  5306 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  5307 INCOMPATIBILITY.
  5308 
  5309 * Locale "partial_order" now unified with class "order" (cf. theory
  5310 Orderings), added parameter "less".  INCOMPATIBILITY.
  5311 
  5312 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  5313 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  5314 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  5315 
  5316 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  5317 changed order of proof goals in instance proofs.
  5318 
  5319 * The transitivity reasoner for partial and linear orders is set up
  5320 for classes "order" and "linorder".  Instances of the reasoner are available
  5321 in all contexts importing or interpreting the corresponding locales.
  5322 Method "order" invokes the reasoner separately; the reasoner
  5323 is also integrated with the Simplifier as a solver.  Diagnostic
  5324 command 'print_orders' shows the available instances of the reasoner
  5325 in the current context.
  5326 
  5327 * Localized monotonicity predicate in theory "Orderings"; integrated
  5328 lemmas max_of_mono and min_of_mono with this predicate.
  5329 INCOMPATIBILITY.
  5330 
  5331 * Formulation of theorem "dense" changed slightly due to integration
  5332 with new class dense_linear_order.
  5333 
  5334 * Uniform lattice theory development in HOL.
  5335 
  5336     constants "meet" and "join" now named "inf" and "sup"
  5337     constant "Meet" now named "Inf"
  5338 
  5339     classes "meet_semilorder" and "join_semilorder" now named
  5340       "lower_semilattice" and "upper_semilattice"
  5341     class "lorder" now named "lattice"
  5342     class "comp_lat" now named "complete_lattice"
  5343 
  5344     Instantiation of lattice classes allows explicit definitions
  5345     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  5346 
  5347   INCOMPATIBILITY.  Theorem renames:
  5348 
  5349     meet_left_le            ~> inf_le1
  5350     meet_right_le           ~> inf_le2
  5351     join_left_le            ~> sup_ge1
  5352     join_right_le           ~> sup_ge2
  5353     meet_join_le            ~> inf_sup_ord
  5354     le_meetI                ~> le_infI
  5355     join_leI                ~> le_supI
  5356     le_meet                 ~> le_inf_iff
  5357     le_join                 ~> ge_sup_conv
  5358     meet_idempotent         ~> inf_idem
  5359     join_idempotent         ~> sup_idem
  5360     meet_comm               ~> inf_commute
  5361     join_comm               ~> sup_commute
  5362     meet_leI1               ~> le_infI1
  5363     meet_leI2               ~> le_infI2
  5364     le_joinI1               ~> le_supI1
  5365     le_joinI2               ~> le_supI2
  5366     meet_assoc              ~> inf_assoc
  5367     join_assoc              ~> sup_assoc
  5368     meet_left_comm          ~> inf_left_commute
  5369     meet_left_idempotent    ~> inf_left_idem
  5370     join_left_comm          ~> sup_left_commute
  5371     join_left_idempotent    ~> sup_left_idem
  5372     meet_aci                ~> inf_aci
  5373     join_aci                ~> sup_aci
  5374     le_def_meet             ~> le_iff_inf
  5375     le_def_join             ~> le_iff_sup
  5376     join_absorp2            ~> sup_absorb2
  5377     join_absorp1            ~> sup_absorb1
  5378     meet_absorp1            ~> inf_absorb1
  5379     meet_absorp2            ~> inf_absorb2
  5380     meet_join_absorp        ~> inf_sup_absorb
  5381     join_meet_absorp        ~> sup_inf_absorb
  5382     distrib_join_le         ~> distrib_sup_le
  5383     distrib_meet_le         ~> distrib_inf_le
  5384 
  5385     add_meet_distrib_left   ~> add_inf_distrib_left
  5386     add_join_distrib_left   ~> add_sup_distrib_left
  5387     is_join_neg_meet        ~> is_join_neg_inf
  5388     is_meet_neg_join        ~> is_meet_neg_sup
  5389     add_meet_distrib_right  ~> add_inf_distrib_right
  5390     add_join_distrib_right  ~> add_sup_distrib_right
  5391     add_meet_join_distribs  ~> add_sup_inf_distribs
  5392     join_eq_neg_meet        ~> sup_eq_neg_inf
  5393     meet_eq_neg_join        ~> inf_eq_neg_sup
  5394     add_eq_meet_join        ~> add_eq_inf_sup
  5395     meet_0_imp_0            ~> inf_0_imp_0
  5396     join_0_imp_0            ~> sup_0_imp_0
  5397     meet_0_eq_0             ~> inf_0_eq_0
  5398     join_0_eq_0             ~> sup_0_eq_0
  5399     neg_meet_eq_join        ~> neg_inf_eq_sup
  5400     neg_join_eq_meet        ~> neg_sup_eq_inf
  5401     join_eq_if              ~> sup_eq_if
  5402 
  5403     mono_meet               ~> mono_inf
  5404     mono_join               ~> mono_sup
  5405     meet_bool_eq            ~> inf_bool_eq
  5406     join_bool_eq            ~> sup_bool_eq
  5407     meet_fun_eq             ~> inf_fun_eq
  5408     join_fun_eq             ~> sup_fun_eq
  5409     meet_set_eq             ~> inf_set_eq
  5410     join_set_eq             ~> sup_set_eq
  5411     meet1_iff               ~> inf1_iff
  5412     meet2_iff               ~> inf2_iff
  5413     meet1I                  ~> inf1I
  5414     meet2I                  ~> inf2I
  5415     meet1D1                 ~> inf1D1
  5416     meet2D1                 ~> inf2D1
  5417     meet1D2                 ~> inf1D2
  5418     meet2D2                 ~> inf2D2
  5419     meet1E                  ~> inf1E
  5420     meet2E                  ~> inf2E
  5421     join1_iff               ~> sup1_iff
  5422     join2_iff               ~> sup2_iff
  5423     join1I1                 ~> sup1I1
  5424     join2I1                 ~> sup2I1
  5425     join1I1                 ~> sup1I1
  5426     join2I2                 ~> sup1I2
  5427     join1CI                 ~> sup1CI
  5428     join2CI                 ~> sup2CI
  5429     join1E                  ~> sup1E
  5430     join2E                  ~> sup2E
  5431 
  5432     is_meet_Meet            ~> is_meet_Inf
  5433     Meet_bool_def           ~> Inf_bool_def
  5434     Meet_fun_def            ~> Inf_fun_def
  5435     Meet_greatest           ~> Inf_greatest
  5436     Meet_lower              ~> Inf_lower
  5437     Meet_set_def            ~> Inf_set_def
  5438 
  5439     Sup_def                 ~> Sup_Inf
  5440     Sup_bool_eq             ~> Sup_bool_def
  5441     Sup_fun_eq              ~> Sup_fun_def
  5442     Sup_set_eq              ~> Sup_set_def
  5443 
  5444     listsp_meetI            ~> listsp_infI
  5445     listsp_meet_eq          ~> listsp_inf_eq
  5446 
  5447     meet_min                ~> inf_min
  5448     join_max                ~> sup_max
  5449 
  5450 * Added syntactic class "size"; overloaded constant "size" now has
  5451 type "'a::size ==> bool"
  5452 
  5453 * Internal reorganisation of `size' of datatypes: size theorems
  5454 "foo.size" are no longer subsumed by "foo.simps" (but are still
  5455 simplification rules by default!); theorems "prod.size" now named
  5456 "*.size".
  5457 
  5458 * Class "div" now inherits from class "times" rather than "type".
  5459 INCOMPATIBILITY.
  5460 
  5461 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  5462 Linorder etc.  have disappeared; operations defined in terms of
  5463 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  5464 
  5465 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  5466 
  5467 * HOL-Word: New extensive library and type for generic, fixed size
  5468 machine words, with arithmetic, bit-wise, shifting and rotating
  5469 operations, reflection into int, nat, and bool lists, automation for
  5470 linear arithmetic (by automatic reflection into nat or int), including
  5471 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  5472 arithmetic type classes, supporting automatic simplification of
  5473 numerals on all operations.
  5474 
  5475 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  5476 
  5477 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  5478 
  5479 * Code generator library theories:
  5480   - Code_Integer represents HOL integers by big integer literals in target
  5481     languages.
  5482   - Code_Char represents HOL characters by character literals in target
  5483     languages.
  5484   - Code_Char_chr like Code_Char, but also offers treatment of character
  5485     codes; includes Code_Integer.
  5486   - Executable_Set allows to generate code for finite sets using lists.
  5487   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  5488     denominator).
  5489   - Executable_Real implements a subset of real numbers, namly those
  5490     representable by rational numbers.
  5491   - Efficient_Nat implements natural numbers by integers, which in general will
  5492     result in higher efficency; pattern matching with 0/Suc is eliminated;
  5493     includes Code_Integer.
  5494   - Code_Index provides an additional datatype index which is mapped to
  5495     target-language built-in integers.
  5496   - Code_Message provides an additional datatype message_string which is isomorphic to
  5497     strings; messages are mapped to target-language strings.
  5498 
  5499 * New package for inductive predicates
  5500 
  5501   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  5502 
  5503     inductive
  5504       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5505       for z_1 :: U_1 and ... and z_n :: U_m
  5506     where
  5507       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  5508     | ...
  5509 
  5510   with full support for type-inference, rather than
  5511 
  5512     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5513 
  5514     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5515     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  5516 
  5517     inductive "s z_1 ... z_m"
  5518     intros
  5519       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  5520       ...
  5521 
  5522   For backward compatibility, there is a wrapper allowing inductive
  5523   sets to be defined with the new package via
  5524 
  5525     inductive_set
  5526       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5527       for z_1 :: U_1 and ... and z_n :: U_m
  5528     where
  5529       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  5530     | ...
  5531 
  5532   or
  5533 
  5534     inductive_set
  5535       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  5536       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  5537       for z_1 :: U_1 and ... and z_n :: U_m
  5538     where
  5539       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  5540     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  5541     | ...
  5542 
  5543   if the additional syntax "p ..." is required.
  5544 
  5545   Numerous examples can be found in the subdirectories src/HOL/Auth,
  5546   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  5547 
  5548   INCOMPATIBILITIES:
  5549 
  5550   - Since declaration and definition of inductive sets or predicates
  5551     is no longer separated, abbreviations involving the newly
  5552     introduced sets or predicates must be specified together with the
  5553     introduction rules after the 'where' keyword (see above), rather
  5554     than before the actual inductive definition.
  5555 
  5556   - The variables in induction and elimination rules are now
  5557     quantified in the order of their occurrence in the introduction
  5558     rules, rather than in alphabetical order. Since this may break
  5559     some proofs, these proofs either have to be repaired, e.g. by
  5560     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  5561     statements of the form
  5562 
  5563       case (rule_i a_i_1 ... a_i_{k_i})
  5564 
  5565     or the old order of quantification has to be restored by explicitly adding
  5566     meta-level quantifiers in the introduction rules, i.e.
  5567 
  5568       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  5569 
  5570   - The format of the elimination rules is now
  5571 
  5572       p z_1 ... z_m x_1 ... x_n ==>
  5573         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5574         ==> ... ==> P
  5575 
  5576     for predicates and
  5577 
  5578       (x_1, ..., x_n) : s z_1 ... z_m ==>
  5579         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5580         ==> ... ==> P
  5581 
  5582     for sets rather than
  5583 
  5584       x : s z_1 ... z_m ==>
  5585         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  5586         ==> ... ==> P
  5587 
  5588     This may require terms in goals to be expanded to n-tuples
  5589     (e.g. using case_tac or simplification with the split_paired_all
  5590     rule) before the above elimination rule is applicable.
  5591 
  5592   - The elimination or case analysis rules for (mutually) inductive
  5593     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  5594     list of rules "p_1_..._p_k.elims" is no longer available.
  5595 
  5596 * New package "function"/"fun" for general recursive functions,
  5597 supporting mutual and nested recursion, definitions in local contexts,
  5598 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  5599 for small examples, and the separate tutorial on the function
  5600 package. The old recdef "package" is still available as before, but
  5601 users are encouraged to use the new package.
  5602 
  5603 * Method "lexicographic_order" automatically synthesizes termination
  5604 relations as lexicographic combinations of size measures. 
  5605 
  5606 * Case-expressions allow arbitrary constructor-patterns (including
  5607 "_") and take their order into account, like in functional
  5608 programming.  Internally, this is translated into nested
  5609 case-expressions; missing cases are added and mapped to the predefined
  5610 constant "undefined". In complicated cases printing may no longer show
  5611 the original input but the internal form. Lambda-abstractions allow
  5612 the same form of pattern matching: "% pat1 => e1 | ..." is an
  5613 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  5614 variable.
  5615 
  5616 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  5617 is an abbreviation for "of_nat :: nat => int". The simplification
  5618 rules for "of_nat" have been changed to work like "int" did
  5619 previously.  Potential INCOMPATIBILITY:
  5620   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  5621   - of_nat_diff and of_nat_mult are no longer default simp rules
  5622 
  5623 * Method "algebra" solves polynomial equations over (semi)rings using
  5624 Groebner bases. The (semi)ring structure is defined by locales and the
  5625 tool setup depends on that generic context. Installing the method for
  5626 a specific type involves instantiating the locale and possibly adding
  5627 declarations for computation on the coefficients.  The method is
  5628 already instantiated for natural numbers and for the axiomatic class
  5629 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  5630 CALCULEMUS 2007 for the general principles underlying this
  5631 architecture of context-aware proof-tools.
  5632 
  5633 * Method "ferrack" implements quantifier elimination over
  5634 special-purpose dense linear orders using locales (analogous to
  5635 "algebra"). The method is already installed for class
  5636 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  5637 rat, etc.
  5638 
  5639 * Former constant "List.op @" now named "List.append".  Use ML
  5640 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  5641 circumvent possible incompatibilities when working on ML level.
  5642 
  5643 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  5644 
  5645 * New function listsum :: 'a list => 'a for arbitrary monoids.
  5646 Special syntax: "SUM x <- xs. f x" (and latex variants)
  5647 
  5648 * New syntax for Haskell-like list comprehension (input only), eg.
  5649 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  5650 
  5651 * The special syntax for function "filter" has changed from [x :
  5652 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  5653 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  5654 
  5655 * [a..b] is now defined for arbitrary linear orders.  It used to be
  5656 defined on nat only, as an abbreviation for [a..<Suc b]
  5657 INCOMPATIBILITY.
  5658 
  5659 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  5660 
  5661 * New functions "sorted" and "sort" in src/HOL/List.thy.
  5662 
  5663 * New lemma collection field_simps (an extension of ring_simps) for
  5664 manipulating (in)equations involving division. Multiplies with all
  5665 denominators that can be proved to be non-zero (in equations) or
  5666 positive/negative (in inequations).
  5667 
  5668 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  5669 have been improved and renamed to ring_simps, group_simps and
  5670 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  5671 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  5672 
  5673 * Theory Library/Commutative_Ring: switched from recdef to function
  5674 package; constants add, mul, pow now curried.  Infix syntax for
  5675 algebraic operations.
  5676 
  5677 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  5678 INCOMPATIBILITY.
  5679 
  5680 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  5681 INCOMPATIBILITY.
  5682 
  5683 * HOL/records: generalised field-update to take a function on the
  5684 field rather than the new value: r(|A := x|) is translated to A_update
  5685 (K x) r The K-combinator that is internally used is called K_record.
  5686 INCOMPATIBILITY: Usage of the plain update functions has to be
  5687 adapted.
  5688  
  5689 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  5690 * x = 0, which are required for a semiring.  Richer structures do not
  5691 inherit from semiring_0 anymore, because this property is a theorem
  5692 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  5693 there is more to prove, but this is mostly trivial.
  5694 
  5695 * Class "recpower" is generalized to arbitrary monoids, not just
  5696 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  5697 commutativity or semiring properties additionally.
  5698 
  5699 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  5700 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  5701 better use 'abbreviation'.
  5702 
  5703 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  5704 
  5705 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  5706 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  5707 significant changes for setting up numeral syntax for types:
  5708   - New constants Numeral.pred and Numeral.succ instead
  5709       of former Numeral.bin_pred and Numeral.bin_succ.
  5710   - Use integer operations instead of bin_add, bin_mult and so on.
  5711   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  5712   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  5713 
  5714 See src/HOL/Integ/IntArith.thy for an example setup.
  5715 
  5716 * Command 'normal_form' computes the normal form of a term that may
  5717 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  5718 produces ``[b, c, a]'' (without proof).  This command is suitable for
  5719 heavy-duty computations because the functions are compiled to ML
  5720 first.  Correspondingly, a method "normalization" is provided.  See
  5721 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  5722 
  5723 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  5724 25 like -->); output depends on the "iff" print_mode, the default is
  5725 "A = B" (with priority 50).
  5726 
  5727 * Relations less (<) and less_eq (<=) are also available on type bool.
  5728 Modified syntax to disallow nesting without explicit parentheses,
  5729 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  5730 INCOMPATIBILITY.
  5731 
  5732 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  5733 
  5734 * Relation composition operator "op O" now has precedence 75 and binds
  5735 stronger than union and intersection. INCOMPATIBILITY.
  5736 
  5737 * The old set interval syntax "{m..n(}" (and relatives) has been
  5738 removed.  Use "{m..<n}" (and relatives) instead.
  5739 
  5740 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  5741 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  5742 ``declare [[simproc del: neq]]''.
  5743 
  5744 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  5745 True/False.
  5746 
  5747 * Theorem Cons_eq_map_conv no longer declared as "simp".
  5748 
  5749 * Theorem setsum_mult renamed to setsum_right_distrib.
  5750 
  5751 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  5752 ``rule'' method.
  5753 
  5754 * Reimplemented methods "sat" and "satx", with several improvements:
  5755 goals no longer need to be stated as "<prems> ==> False", equivalences
  5756 (i.e. "=" on type bool) are handled, variable names of the form
  5757 "lit_<n>" are no longer reserved, significant speedup.
  5758 
  5759 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  5760 zChaff is still supported as well.
  5761 
  5762 * 'inductive' and 'datatype': provide projections of mutual rules,
  5763 bundled as foo_bar.inducts;
  5764 
  5765 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  5766 Library.
  5767 
  5768 * Library: moved theory Accessible_Part to main HOL.
  5769 
  5770 * Library: added theory Coinductive_List of potentially infinite lists
  5771 as greatest fixed-point.
  5772 
  5773 * Library: added theory AssocList which implements (finite) maps as
  5774 association lists.
  5775 
  5776 * Method "evaluation" solves goals (i.e. a boolean expression)
  5777 efficiently by compiling it to ML.  The goal is "proved" (via an
  5778 oracle) if it evaluates to True.
  5779 
  5780 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  5781 also when invoked by the simplifier.  This results in the Simplifier
  5782 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  5783 Configuration option fast_arith_split_limit=0 recovers the old
  5784 behavior.
  5785 
  5786 * Support for hex (0x20) and binary (0b1001) numerals.
  5787 
  5788 * New method: reify eqs (t), where eqs are equations for an
  5789 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  5790 parameter, computes a term s::'b and a list xs::'a list and proves the
  5791 theorem I xs s = t. This is also known as reification or quoting. The
  5792 resulting theorem is applied to the subgoal to substitute t with I xs
  5793 s.  If t is omitted, the subgoal itself is reified.
  5794 
  5795 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  5796 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  5797 where f is supposed to be a computable function (in the sense of code
  5798 generattion). The method uses reify to compute s and xs as above then
  5799 applies corr_thm and uses normalization by evaluation to "prove" f s =
  5800 r and finally gets the theorem t = r, which is again applied to the
  5801 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  5802 
  5803 * Reflection: Automatic reification now handels binding, an example is
  5804 available in src/HOL/ex/ReflectionEx.thy
  5805 
  5806 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  5807 command 'statespace' that is similar to 'record', but introduces an
  5808 abstract specification based on the locale infrastructure instead of
  5809 HOL types.  This leads to extra flexibility in composing state spaces,
  5810 in particular multiple inheritance and renaming of components.
  5811 
  5812 
  5813 *** HOL-Complex ***
  5814 
  5815 * Hyperreal: Functions root and sqrt are now defined on negative real
  5816 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  5817 Nonnegativity side conditions have been removed from many lemmas, so
  5818 that more subgoals may now be solved by simplification; potential
  5819 INCOMPATIBILITY.
  5820 
  5821 * Real: new type classes formalize real normed vector spaces and
  5822 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  5823 and norm :: 'a => real.
  5824 
  5825 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  5826 reals into other types. The overloaded constant Reals :: 'a set is now
  5827 defined as range of_real; potential INCOMPATIBILITY.
  5828 
  5829 * Real: proper support for ML code generation, including 'quickcheck'.
  5830 Reals are implemented as arbitrary precision rationals.
  5831 
  5832 * Hyperreal: Several constants that previously worked only for the
  5833 reals have been generalized, so they now work over arbitrary vector
  5834 spaces. Type annotations may need to be added in some cases; potential
  5835 INCOMPATIBILITY.
  5836 
  5837   Infinitesimal  :: ('a::real_normed_vector) star set
  5838   HFinite        :: ('a::real_normed_vector) star set
  5839   HInfinite      :: ('a::real_normed_vector) star set
  5840   approx         :: ('a::real_normed_vector) star => 'a star => bool
  5841   monad          :: ('a::real_normed_vector) star => 'a star set
  5842   galaxy         :: ('a::real_normed_vector) star => 'a star set
  5843   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  5844   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  5845   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  5846   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  5847   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  5848   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  5849   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5850   sgn            :: 'a::real_normed_vector => 'a
  5851   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5852 
  5853 * Complex: Some complex-specific constants are now abbreviations for
  5854 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5855 hnorm.  Other constants have been entirely removed in favor of the
  5856 polymorphic versions (INCOMPATIBILITY):
  5857 
  5858   approx        <-- capprox
  5859   HFinite       <-- CFinite
  5860   HInfinite     <-- CInfinite
  5861   Infinitesimal <-- CInfinitesimal
  5862   monad         <-- cmonad
  5863   galaxy        <-- cgalaxy
  5864   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5865   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5866   (ns)deriv     <-- (ns)cderiv
  5867 
  5868 
  5869 *** HOL-Algebra ***
  5870 
  5871 * Formalisation of ideals and the quotient construction over rings.
  5872 
  5873 * Order and lattice theory no longer based on records.
  5874 INCOMPATIBILITY.
  5875 
  5876 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5877 greatest_closed.  INCOMPATIBILITY.
  5878 
  5879 * Method algebra is now set up via an attribute.  For examples see
  5880 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5881 of algebraic structures.
  5882 
  5883 * Renamed theory CRing to Ring.
  5884 
  5885 
  5886 *** HOL-Nominal ***
  5887 
  5888 * Substantial, yet incomplete support for nominal datatypes (binding
  5889 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5890 src/HOL/Nominal/Examples.  Prospective users should consult
  5891 http://isabelle.in.tum.de/nominal/
  5892 
  5893 
  5894 *** ML ***
  5895 
  5896 * ML basics: just one true type int, which coincides with IntInf.int
  5897 (even on SML/NJ).
  5898 
  5899 * ML within Isar: antiquotations allow to embed statically-checked
  5900 formal entities in the source, referring to the context available at
  5901 compile-time.  For example:
  5902 
  5903 ML {* @{sort "{zero,one}"} *}
  5904 ML {* @{typ "'a => 'b"} *}
  5905 ML {* @{term "%x. x"} *}
  5906 ML {* @{prop "x == y"} *}
  5907 ML {* @{ctyp "'a => 'b"} *}
  5908 ML {* @{cterm "%x. x"} *}
  5909 ML {* @{cprop "x == y"} *}
  5910 ML {* @{thm asm_rl} *}
  5911 ML {* @{thms asm_rl} *}
  5912 ML {* @{type_name c} *}
  5913 ML {* @{type_syntax c} *}
  5914 ML {* @{const_name c} *}
  5915 ML {* @{const_syntax c} *}
  5916 ML {* @{context} *}
  5917 ML {* @{theory} *}
  5918 ML {* @{theory Pure} *}
  5919 ML {* @{theory_ref} *}
  5920 ML {* @{theory_ref Pure} *}
  5921 ML {* @{simpset} *}
  5922 ML {* @{claset} *}
  5923 ML {* @{clasimpset} *}
  5924 
  5925 The same works for sources being ``used'' within an Isar context.
  5926 
  5927 * ML in Isar: improved error reporting; extra verbosity with
  5928 ML_Context.trace enabled.
  5929 
  5930 * Pure/General/table.ML: the join operations now works via exceptions
  5931 DUP/SAME instead of type option. This is simpler in simple cases, and
  5932 admits slightly more efficient complex applications.
  5933 
  5934 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5935 use Context.generic instead of just theory.
  5936 
  5937 * Pure: datatype Context.generic joins theory/Proof.context and
  5938 provides some facilities for code that works in either kind of
  5939 context, notably GenericDataFun for uniform theory and proof data.
  5940 
  5941 * Pure: simplified internal attribute type, which is now always
  5942 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5943 local (Proof.context) attributes have been discontinued, while
  5944 minimizing code duplication. Thm.rule_attribute and
  5945 Thm.declaration_attribute build canonical attributes; see also structure
  5946 Context for further operations on Context.generic, notably
  5947 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5948 declarations and definitions.
  5949 
  5950 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5951 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5952 init only required for impure data. INCOMPATIBILITY: empty really need
  5953 to be empty (no dependencies on theory content!)
  5954 
  5955 * Pure/kernel: consts certification ignores sort constraints given in
  5956 signature declarations. (This information is not relevant to the
  5957 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5958 potential INCOMPATIBILITY.
  5959 
  5960 * Pure: axiomatic type classes are now purely definitional, with
  5961 explicit proofs of class axioms and super class relations performed
  5962 internally. See Pure/axclass.ML for the main internal interfaces --
  5963 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5964 AxClass.axiomatize_class/classrel/arity supersede
  5965 Sign.add_classes/classrel/arities.
  5966 
  5967 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5968 global/local versions on theory vs. Proof.context have been
  5969 discontinued; Attrib.syntax and Method.syntax have been adapted
  5970 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5971 attributes, methods, etc.
  5972 
  5973 * Pure: several functions of signature "... -> theory -> theory * ..."
  5974 have been reoriented to "... -> theory -> ... * theory" in order to
  5975 allow natural usage in combination with the ||>, ||>>, |-> and
  5976 fold_map combinators.
  5977 
  5978 * Pure: official theorem names (closed derivations) and additional
  5979 comments (tags) are now strictly separate.  Name hints -- which are
  5980 maintained as tags -- may be attached any time without affecting the
  5981 derivation.
  5982 
  5983 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5984 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5985 achieve the old behaviour.
  5986 
  5987 * Pure: the "Goal" constant is now called "prop", supporting a
  5988 slightly more general idea of ``protecting'' meta-level rule
  5989 statements.
  5990 
  5991 * Pure: Logic.(un)varify only works in a global context, which is now
  5992 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5993 Logic.legacy_(un)varify as temporary workaround.
  5994 
  5995 * Pure: structure Name provides scalable operations for generating
  5996 internal variable names, notably Name.variants etc.  This replaces
  5997 some popular functions from term.ML:
  5998 
  5999   Term.variant		->  Name.variant
  6000   Term.variantlist	->  Name.variant_list
  6001   Term.invent_names	->  Name.invent_list
  6002 
  6003 Note that low-level renaming rarely occurs in new code -- operations
  6004 from structure Variable are used instead (see below).
  6005 
  6006 * Pure: structure Variable provides fundamental operations for proper
  6007 treatment of fixed/schematic variables in a context.  For example,
  6008 Variable.import introduces fixes for schematics of given facts and
  6009 Variable.export reverses the effect (up to renaming) -- this replaces
  6010 various freeze_thaw operations.
  6011 
  6012 * Pure: structure Goal provides simple interfaces for
  6013 init/conclude/finish and tactical prove operations (replacing former
  6014 Tactic.prove).  Goal.prove is the canonical way to prove results
  6015 within a given context; Goal.prove_global is a degraded version for
  6016 theory level goals, including a global Drule.standard.  Note that
  6017 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  6018 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  6019 in a locale context).
  6020 
  6021 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  6022 and type checking (Syntax.check_term etc.), with common combinations
  6023 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  6024 which are considered legacy and await removal.
  6025 
  6026 * Pure/Syntax: generic interfaces for type unchecking
  6027 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  6028 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  6029 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  6030 available for convenience, but refer to the very same operations using
  6031 a mere theory instead of a full context.
  6032 
  6033 * Isar: simplified treatment of user-level errors, using exception
  6034 ERROR of string uniformly.  Function error now merely raises ERROR,
  6035 without any side effect on output channels.  The Isar toplevel takes
  6036 care of proper display of ERROR exceptions.  ML code may use plain
  6037 handle/can/try; cat_error may be used to concatenate errors like this:
  6038 
  6039   ... handle ERROR msg => cat_error msg "..."
  6040 
  6041 Toplevel ML code (run directly or through the Isar toplevel) may be
  6042 embedded into the Isar toplevel with exception display/debug like
  6043 this:
  6044 
  6045   Isar.toplevel (fn () => ...)
  6046 
  6047 INCOMPATIBILITY, removed special transform_error facilities, removed
  6048 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  6049 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  6050 -- use plain ERROR instead.
  6051 
  6052 * Isar: theory setup now has type (theory -> theory), instead of a
  6053 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  6054 
  6055 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  6056 ProofContext.debug/verbose flags.
  6057 
  6058 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  6059 theory before entering a proof state.  Transactions now always see a
  6060 quasi-functional intermediate checkpoint, both in interactive and
  6061 batch mode.
  6062 
  6063 * Isar: simplified interfaces for outer syntax.  Renamed
  6064 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  6065 OuterSyntax.add_parsers -- this functionality is now included in
  6066 OuterSyntax.command etc.  INCOMPATIBILITY.
  6067 
  6068 * Simplifier: the simpset of a running simplification process now
  6069 contains a proof context (cf. Simplifier.the_context), which is the
  6070 very context that the initial simpset has been retrieved from (by
  6071 simpset_of/local_simpset_of).  Consequently, all plug-in components
  6072 (solver, looper etc.) may depend on arbitrary proof data.
  6073 
  6074 * Simplifier.inherit_context inherits the proof context (plus the
  6075 local bounds) of the current simplification process; any simproc
  6076 etc. that calls the Simplifier recursively should do this!  Removed
  6077 former Simplifier.inherit_bounds, which is already included here --
  6078 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  6079 specify an explicit context using Simplifier.context/theory_context.
  6080 
  6081 * Simplifier/Classical Reasoner: more abstract interfaces
  6082 change_simpset/claset for modifying the simpset/claset reference of a
  6083 theory; raw versions simpset/claset_ref etc. have been discontinued --
  6084 INCOMPATIBILITY.
  6085 
  6086 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  6087 "Trueprop" etc.
  6088 
  6089 
  6090 *** System ***
  6091 
  6092 * settings: the default heap location within ISABELLE_HOME_USER now
  6093 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  6094 Isabelle installations.
  6095 
  6096 * isabelle-process: option -S (secure mode) disables some critical
  6097 operations, notably runtime compilation and evaluation of ML source
  6098 code.
  6099 
  6100 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  6101 
  6102 * Support for parallel execution, using native multicore support of
  6103 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  6104 independent theories, according to the given theory header
  6105 specifications. The maximum number of worker threads is specified via
  6106 usedir option -M or the "max-threads" setting in Proof General. A
  6107 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  6108 to 6 on a 8-core machine.  User-code needs to observe certain
  6109 guidelines for thread-safe programming, see appendix A in the Isar
  6110 Implementation manual.
  6111 
  6112 
  6113 
  6114 New in Isabelle2005 (October 2005)
  6115 ----------------------------------
  6116 
  6117 *** General ***
  6118 
  6119 * Theory headers: the new header syntax for Isar theories is
  6120 
  6121   theory <name>
  6122   imports <theory1> ... <theoryN>
  6123   uses <file1> ... <fileM>
  6124   begin
  6125 
  6126 where the 'uses' part is optional.  The previous syntax
  6127 
  6128   theory <name> = <theory1> + ... + <theoryN>:
  6129 
  6130 will disappear in the next release.  Use isatool fixheaders to convert
  6131 existing theory files.  Note that there is no change in ancient
  6132 non-Isar theories now, but these will disappear soon.
  6133 
  6134 * Theory loader: parent theories can now also be referred to via
  6135 relative and absolute paths.
  6136 
  6137 * Command 'find_theorems' searches for a list of criteria instead of a
  6138 list of constants. Known criteria are: intro, elim, dest, name:string,
  6139 simp:term, and any term. Criteria can be preceded by '-' to select
  6140 theorems that do not match. Intro, elim, dest select theorems that
  6141 match the current goal, name:s selects theorems whose fully qualified
  6142 name contain s, and simp:term selects all simplification rules whose
  6143 lhs match term.  Any other term is interpreted as pattern and selects
  6144 all theorems matching the pattern. Available in ProofGeneral under
  6145 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  6146 
  6147   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  6148 
  6149 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  6150 matching the current goal as introduction rule and not having "HOL."
  6151 in their name (i.e. not being defined in theory HOL).
  6152 
  6153 * Command 'thms_containing' has been discontinued in favour of
  6154 'find_theorems'; INCOMPATIBILITY.
  6155 
  6156 * Communication with Proof General is now 8bit clean, which means that
  6157 Unicode text in UTF-8 encoding may be used within theory texts (both
  6158 formal and informal parts).  Cf. option -U of the Isabelle Proof
  6159 General interface.  Here are some simple examples (cf. src/HOL/ex):
  6160 
  6161   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  6162   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  6163 
  6164 * Improved efficiency of the Simplifier and, to a lesser degree, the
  6165 Classical Reasoner.  Typical big applications run around 2 times
  6166 faster.
  6167 
  6168 
  6169 *** Document preparation ***
  6170 
  6171 * Commands 'display_drafts' and 'print_drafts' perform simple output
  6172 of raw sources.  Only those symbols that do not require additional
  6173 LaTeX packages (depending on comments in isabellesym.sty) are
  6174 displayed properly, everything else is left verbatim.  isatool display
  6175 and isatool print are used as front ends (these are subject to the
  6176 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  6177 
  6178 * Command tags control specific markup of certain regions of text,
  6179 notably folding and hiding.  Predefined tags include "theory" (for
  6180 theory begin and end), "proof" for proof commands, and "ML" for
  6181 commands involving ML code; the additional tags "visible" and
  6182 "invisible" are unused by default.  Users may give explicit tag
  6183 specifications in the text, e.g. ''by %invisible (auto)''.  The
  6184 interpretation of tags is determined by the LaTeX job during document
  6185 preparation: see option -V of isatool usedir, or options -n and -t of
  6186 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  6187 \isadroptag.
  6188 
  6189 Several document versions may be produced at the same time via isatool
  6190 usedir (the generated index.html will link all of them).  Typical
  6191 specifications include ''-V document=theory,proof,ML'' to present
  6192 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  6193 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  6194 these parts without any formal replacement text.  The Isabelle site
  6195 default settings produce ''document'' and ''outline'' versions as
  6196 specified above.
  6197 
  6198 * Several new antiquotations:
  6199 
  6200   @{term_type term} prints a term with its type annotated;
  6201 
  6202   @{typeof term} prints the type of a term;
  6203 
  6204   @{const const} is the same as @{term const}, but checks that the
  6205   argument is a known logical constant;
  6206 
  6207   @{term_style style term} and @{thm_style style thm} print a term or
  6208   theorem applying a "style" to it
  6209 
  6210   @{ML text}
  6211 
  6212 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  6213 definitions, equations, inequations etc., 'concl' printing only the
  6214 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  6215 to print the specified premise.  TermStyle.add_style provides an ML
  6216 interface for introducing further styles.  See also the "LaTeX Sugar"
  6217 document practical applications.  The ML antiquotation prints
  6218 type-checked ML expressions verbatim.
  6219 
  6220 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  6221 and 'text' support optional locale specification '(in loc)', which
  6222 specifies the default context for interpreting antiquotations.  For
  6223 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  6224 
  6225 * Option 'locale=NAME' of antiquotations specifies an alternative
  6226 context interpreting the subsequent argument.  For example: @{thm
  6227 [locale=lattice] inf_assoc}.
  6228 
  6229 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  6230 a proof context.
  6231 
  6232 * Proper output of antiquotations for theory commands involving a
  6233 proof context (such as 'locale' or 'theorem (in loc) ...').
  6234 
  6235 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  6236 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  6237 
  6238 * isatool usedir: new option -C (default true) controls whether option
  6239 -D should include a copy of the original document directory; -C false
  6240 prevents unwanted effects such as copying of administrative CVS data.
  6241 
  6242 
  6243 *** Pure ***
  6244 
  6245 * Considerably improved version of 'constdefs' command.  Now performs
  6246 automatic type-inference of declared constants; additional support for
  6247 local structure declarations (cf. locales and HOL records), see also
  6248 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  6249 sequential dependencies of definitions within a single 'constdefs'
  6250 section; moreover, the declared name needs to be an identifier.  If
  6251 all fails, consider to fall back on 'consts' and 'defs' separately.
  6252 
  6253 * Improved indexed syntax and implicit structures.  First of all,
  6254 indexed syntax provides a notational device for subscripted
  6255 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  6256 expressions.  Secondly, in a local context with structure
  6257 declarations, number indexes \<^sub>n or the empty index (default
  6258 number 1) refer to a certain fixed variable implicitly; option
  6259 show_structs controls printing of implicit structures.  Typical
  6260 applications of these concepts involve record types and locales.
  6261 
  6262 * New command 'no_syntax' removes grammar declarations (and
  6263 translations) resulting from the given syntax specification, which is
  6264 interpreted in the same manner as for the 'syntax' command.
  6265 
  6266 * 'Advanced' translation functions (parse_translation etc.) may depend
  6267 on the signature of the theory context being presently used for
  6268 parsing/printing, see also isar-ref manual.
  6269 
  6270 * Improved 'oracle' command provides a type-safe interface to turn an
  6271 ML expression of type theory -> T -> term into a primitive rule of
  6272 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  6273 is already included here); see also FOL/ex/IffExample.thy;
  6274 INCOMPATIBILITY.
  6275 
  6276 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  6277 before); "cI" is no longer bound, use "c.intro" instead.
  6278 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  6279 axclasses vs. locales.
  6280 
  6281 * Improved internal renaming of symbolic identifiers -- attach primes
  6282 instead of base 26 numbers.
  6283 
  6284 * New flag show_question_marks controls printing of leading question
  6285 marks in schematic variable names.
  6286 
  6287 * In schematic variable names, *any* symbol following \<^isub> or
  6288 \<^isup> is now treated as part of the base name.  For example, the
  6289 following works without printing of awkward ".0" indexes:
  6290 
  6291   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  6292     by simp
  6293 
  6294 * Inner syntax includes (*(*nested*) comments*).
  6295 
  6296 * Pretty printer now supports unbreakable blocks, specified in mixfix
  6297 annotations as "(00...)".
  6298 
  6299 * Clear separation of logical types and nonterminals, where the latter
  6300 may only occur in 'syntax' specifications or type abbreviations.
  6301 Before that distinction was only partially implemented via type class
  6302 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  6303 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  6304 exotic syntax specifications may require further adaption
  6305 (e.g. Cube/Cube.thy).
  6306 
  6307 * Removed obsolete type class "logic", use the top sort {} instead.
  6308 Note that non-logical types should be declared as 'nonterminals'
  6309 rather than 'types'.  INCOMPATIBILITY for new object-logic
  6310 specifications.
  6311 
  6312 * Attributes 'induct' and 'cases': type or set names may now be
  6313 locally fixed variables as well.
  6314 
  6315 * Simplifier: can now control the depth to which conditional rewriting
  6316 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  6317 Limit.
  6318 
  6319 * Simplifier: simplification procedures may now take the current
  6320 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  6321 interface), which is very useful for calling the Simplifier
  6322 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  6323 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  6324 low-level mk_simproc no longer applies Logic.varify internally, to
  6325 allow for use in a context of fixed variables.
  6326 
  6327 * thin_tac now works even if the assumption being deleted contains !!
  6328 or ==>.  More generally, erule now works even if the major premise of
  6329 the elimination rule contains !! or ==>.
  6330 
  6331 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  6332 
  6333 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  6334 from Pure, which contains all common declarations already.  Both
  6335 theories are defined via plain Isabelle/Isar .thy files.
  6336 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  6337 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  6338 use isatool fixcpure to adapt your theory and ML sources.
  6339 
  6340 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  6341 selections of theorems in named facts via index ranges.
  6342 
  6343 * 'print_theorems': in theory mode, really print the difference
  6344 wrt. the last state (works for interactive theory development only),
  6345 in proof mode print all local facts (cf. 'print_facts');
  6346 
  6347 * 'hide': option '(open)' hides only base names.
  6348 
  6349 * More efficient treatment of intermediate checkpoints in interactive
  6350 theory development.
  6351 
  6352 * Code generator is now invoked via code_module (incremental code
  6353 generation) and code_library (modular code generation, ML structures
  6354 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  6355 must be quoted when used as identifiers.
  6356 
  6357 * New 'value' command for reading, evaluating and printing terms using
  6358 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  6359 quoted when used as identifier.
  6360 
  6361 
  6362 *** Locales ***
  6363 
  6364 * New commands for the interpretation of locale expressions in
  6365 theories (1), locales (2) and proof contexts (3).  These generate
  6366 proof obligations from the expression specification.  After the
  6367 obligations have been discharged, theorems of the expression are added
  6368 to the theory, target locale or proof context.  The synopsis of the
  6369 commands is a follows:
  6370 
  6371   (1) interpretation expr inst
  6372   (2) interpretation target < expr
  6373   (3) interpret expr inst
  6374 
  6375 Interpretation in theories and proof contexts require a parameter
  6376 instantiation of terms from the current context.  This is applied to
  6377 specifications and theorems of the interpreted expression.
  6378 Interpretation in locales only permits parameter renaming through the
  6379 locale expression.  Interpretation is smart in that interpretations
  6380 that are active already do not occur in proof obligations, neither are
  6381 instantiated theorems stored in duplicate.  Use 'print_interps' to
  6382 inspect active interpretations of a particular locale.  For details,
  6383 see the Isar Reference manual.  Examples can be found in
  6384 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  6385 
  6386 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  6387 'interpret' instead.
  6388 
  6389 * New context element 'constrains' for adding type constraints to
  6390 parameters.
  6391 
  6392 * Context expressions: renaming of parameters with syntax
  6393 redeclaration.
  6394 
  6395 * Locale declaration: 'includes' disallowed.
  6396 
  6397 * Proper static binding of attribute syntax -- i.e. types / terms /
  6398 facts mentioned as arguments are always those of the locale definition
  6399 context, independently of the context of later invocations.  Moreover,
  6400 locale operations (renaming and type / term instantiation) are applied
  6401 to attribute arguments as expected.
  6402 
  6403 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  6404 actual attributes; rare situations may require Attrib.attribute to
  6405 embed those attributes into Attrib.src that lack concrete syntax.
  6406 Attribute implementations need to cooperate properly with the static
  6407 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  6408 Attrib.XXX_thm etc. already do the right thing without further
  6409 intervention.  Only unusual applications -- such as "where" or "of"
  6410 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  6411 on the context and the facts involved -- may have to assign parsed
  6412 values to argument tokens explicitly.
  6413 
  6414 * Changed parameter management in theorem generation for long goal
  6415 statements with 'includes'.  INCOMPATIBILITY: produces a different
  6416 theorem statement in rare situations.
  6417 
  6418 * Locale inspection command 'print_locale' omits notes elements.  Use
  6419 'print_locale!' to have them included in the output.
  6420 
  6421 
  6422 *** Provers ***
  6423 
  6424 * Provers/hypsubst.ML: improved version of the subst method, for
  6425 single-step rewriting: it now works in bound variable contexts. New is
  6426 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  6427 rewrite a different subterm than the original subst method, which is
  6428 still available as 'simplesubst'.
  6429 
  6430 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  6431 and quasi orders.
  6432 
  6433 * Provers/trancl.ML: new transitivity reasoner for transitive and
  6434 reflexive-transitive closure of relations.
  6435 
  6436 * Provers/blast.ML: new reference depth_limit to make blast's depth
  6437 limit (previously hard-coded with a value of 20) user-definable.
  6438 
  6439 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  6440 is peformed already.  Object-logics merely need to finish their
  6441 initial simpset configuration as before.  INCOMPATIBILITY.
  6442 
  6443 
  6444 *** HOL ***
  6445 
  6446 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  6447 
  6448   syntax (epsilon)
  6449     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  6450 
  6451 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  6452 and x-symbol; use option '-m epsilon' to get it actually printed.
  6453 Moreover, the mathematically important symbolic identifier \<epsilon>
  6454 becomes available as variable, constant etc.  INCOMPATIBILITY,
  6455 
  6456 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  6457 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  6458 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  6459 support corresponding Isar calculations.
  6460 
  6461 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  6462 instead of ":".
  6463 
  6464 * theory SetInterval: changed the syntax for open intervals:
  6465 
  6466   Old       New
  6467   {..n(}    {..<n}
  6468   {)n..}    {n<..}
  6469   {m..n(}   {m..<n}
  6470   {)m..n}   {m<..n}
  6471   {)m..n(}  {m<..<n}
  6472 
  6473 The old syntax is still supported but will disappear in the next
  6474 release.  For conversion use the following Emacs search and replace
  6475 patterns (these are not perfect but work quite well):
  6476 
  6477   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  6478   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  6479 
  6480 * Theory Commutative_Ring (in Library): method comm_ring for proving
  6481 equalities in commutative rings; method 'algebra' provides a generic
  6482 interface.
  6483 
  6484 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  6485 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  6486 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  6487 be a tuple pattern.
  6488 
  6489 Some new syntax forms are available:
  6490 
  6491   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  6492   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  6493   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  6494   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  6495 
  6496 The latter form "\<Sum>x < k. e" used to be based on a separate
  6497 function "Summation", which has been discontinued.
  6498 
  6499 * theory Finite_Set: in structured induction proofs, the insert case
  6500 is now 'case (insert x F)' instead of the old counterintuitive 'case
  6501 (insert F x)'.
  6502 
  6503 * The 'refute' command has been extended to support a much larger
  6504 fragment of HOL, including axiomatic type classes, constdefs and
  6505 typedefs, inductive datatypes and recursion.
  6506 
  6507 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  6508 Requires zChaff with proof generation to be installed.  See
  6509 HOL/ex/SAT_Examples.thy for examples.
  6510 
  6511 * Datatype induction via method 'induct' now preserves the name of the
  6512 induction variable. For example, when proving P(xs::'a list) by
  6513 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  6514 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  6515 in unstructured proof scripts.
  6516 
  6517 * Reworked implementation of records.  Improved scalability for
  6518 records with many fields, avoiding performance problems for type
  6519 inference. Records are no longer composed of nested field types, but
  6520 of nested extension types. Therefore the record type only grows linear
  6521 in the number of extensions and not in the number of fields.  The
  6522 top-level (users) view on records is preserved.  Potential
  6523 INCOMPATIBILITY only in strange cases, where the theory depends on the
  6524 old record representation. The type generated for a record is called
  6525 <record_name>_ext_type.
  6526 
  6527 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  6528 proofs triggered by a record definition or a simproc (if
  6529 quick_and_dirty is enabled).  Definitions of large records can take
  6530 quite long.
  6531 
  6532 New simproc record_upd_simproc for simplification of multiple record
  6533 updates enabled by default.  Moreover, trivial updates are also
  6534 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  6535 occasionally, since simplification is more powerful by default.
  6536 
  6537 * typedef: proper support for polymorphic sets, which contain extra
  6538 type-variables in the term.
  6539 
  6540 * Simplifier: automatically reasons about transitivity chains
  6541 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  6542 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  6543 old proofs break occasionally as simplification may now solve more
  6544 goals than previously.
  6545 
  6546 * Simplifier: converts x <= y into x = y if assumption y <= x is
  6547 present.  Works for all partial orders (class "order"), in particular
  6548 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  6549 just like y <= x.
  6550 
  6551 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  6552 bound variable or a constant then the let is unfolded.  Otherwise
  6553 first a is simplified to b, and then f b is simplified to g. If
  6554 possible we abstract b from g arriving at "let x = b in h x",
  6555 otherwise we unfold the let and arrive at g.  The simproc can be
  6556 enabled/disabled by the reference use_let_simproc.  Potential
  6557 INCOMPATIBILITY since simplification is more powerful by default.
  6558 
  6559 * Classical reasoning: the meson method now accepts theorems as arguments.
  6560 
  6561 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  6562 jobs to provide advice on the provability of subgoals.
  6563 
  6564 * Theory OrderedGroup and Ring_and_Field: various additions and
  6565 improvements to faciliate calculations involving equalities and
  6566 inequalities.
  6567 
  6568 The following theorems have been eliminated or modified
  6569 (INCOMPATIBILITY):
  6570 
  6571   abs_eq             now named abs_of_nonneg
  6572   abs_of_ge_0        now named abs_of_nonneg
  6573   abs_minus_eq       now named abs_of_nonpos
  6574   imp_abs_id         now named abs_of_nonneg
  6575   imp_abs_neg_id     now named abs_of_nonpos
  6576   mult_pos           now named mult_pos_pos
  6577   mult_pos_le        now named mult_nonneg_nonneg
  6578   mult_pos_neg_le    now named mult_nonneg_nonpos
  6579   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  6580   mult_neg           now named mult_neg_neg
  6581   mult_neg_le        now named mult_nonpos_nonpos
  6582 
  6583 * The following lemmas in Ring_and_Field have been added to the simplifier:
  6584      
  6585      zero_le_square
  6586      not_square_less_zero 
  6587 
  6588   The following lemmas have been deleted from Real/RealPow:
  6589   
  6590      realpow_zero_zero
  6591      realpow_two
  6592      realpow_less
  6593      zero_le_power
  6594      realpow_two_le
  6595      abs_realpow_two
  6596      realpow_two_abs     
  6597 
  6598 * Theory Parity: added rules for simplifying exponents.
  6599 
  6600 * Theory List:
  6601 
  6602 The following theorems have been eliminated or modified
  6603 (INCOMPATIBILITY):
  6604 
  6605   list_all_Nil       now named list_all.simps(1)
  6606   list_all_Cons      now named list_all.simps(2)
  6607   list_all_conv      now named list_all_iff
  6608   set_mem_eq         now named mem_iff
  6609 
  6610 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  6611 asymptotic "big O" calculations.  See the notes in BigO.thy.
  6612 
  6613 
  6614 *** HOL-Complex ***
  6615 
  6616 * Theory RealDef: better support for embedding natural numbers and
  6617 integers in the reals.
  6618 
  6619 The following theorems have been eliminated or modified
  6620 (INCOMPATIBILITY):
  6621 
  6622   exp_ge_add_one_self  now requires no hypotheses
  6623   real_of_int_add      reversed direction of equality (use [symmetric])
  6624   real_of_int_minus    reversed direction of equality (use [symmetric])
  6625   real_of_int_diff     reversed direction of equality (use [symmetric])
  6626   real_of_int_mult     reversed direction of equality (use [symmetric])
  6627 
  6628 * Theory RComplete: expanded support for floor and ceiling functions.
  6629 
  6630 * Theory Ln is new, with properties of the natural logarithm
  6631 
  6632 * Hyperreal: There is a new type constructor "star" for making
  6633 nonstandard types.  The old type names are now type synonyms:
  6634 
  6635   hypreal = real star
  6636   hypnat = nat star
  6637   hcomplex = complex star
  6638 
  6639 * Hyperreal: Many groups of similarly-defined constants have been
  6640 replaced by polymorphic versions (INCOMPATIBILITY):
  6641 
  6642   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  6643 
  6644   starset      <-- starsetNat, starsetC
  6645   *s*          <-- *sNat*, *sc*
  6646   starset_n    <-- starsetNat_n, starsetC_n
  6647   *sn*         <-- *sNatn*, *scn*
  6648   InternalSets <-- InternalNatSets, InternalCSets
  6649 
  6650   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  6651   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  6652   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  6653   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  6654   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  6655 
  6656 * Hyperreal: Many type-specific theorems have been removed in favor of
  6657 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  6658 
  6659   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  6660   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  6661   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  6662   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  6663   right_minus <-- hypreal_add_minus
  6664   left_minus <-- {hypreal,hcomplex}_add_minus_left
  6665   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  6666   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  6667   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  6668   mult_1_right <-- hcomplex_mult_one_right
  6669   mult_zero_left <-- hcomplex_mult_zero_left
  6670   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  6671   right_distrib <-- hypnat_add_mult_distrib2
  6672   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  6673   right_inverse <-- hypreal_mult_inverse
  6674   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  6675   order_refl <-- {hypreal,hypnat}_le_refl
  6676   order_trans <-- {hypreal,hypnat}_le_trans
  6677   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  6678   order_less_le <-- {hypreal,hypnat}_less_le
  6679   linorder_linear <-- {hypreal,hypnat}_le_linear
  6680   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  6681   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  6682   add_nonneg_nonneg <-- hypreal_le_add_order
  6683 
  6684 * Hyperreal: Separate theorems having to do with type-specific
  6685 versions of constants have been merged into theorems that apply to the
  6686 new polymorphic constants (INCOMPATIBILITY):
  6687 
  6688   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  6689   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  6690   STAR_Un <-- {STAR,NatStar,STARC}_Un
  6691   STAR_Int <-- {STAR,NatStar,STARC}_Int
  6692   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  6693   STAR_subset <-- {STAR,NatStar,STARC}_subset
  6694   STAR_mem <-- {STAR,NatStar,STARC}_mem
  6695   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  6696   STAR_diff <-- {STAR,STARC}_diff
  6697   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  6698     STARC_hcomplex_of_complex}_image_subset
  6699   starset_n_Un <-- starset{Nat,C}_n_Un
  6700   starset_n_Int <-- starset{Nat,C}_n_Int
  6701   starset_n_Compl <-- starset{Nat,C}_n_Compl
  6702   starset_n_diff <-- starset{Nat,C}_n_diff
  6703   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  6704   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  6705   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  6706   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  6707   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  6708   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  6709   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  6710   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  6711   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  6712   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  6713   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  6714   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  6715   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  6716   starfun_diff <-- starfun{C,RC,CR}_diff
  6717   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  6718   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  6719   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  6720   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  6721   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  6722   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  6723   starfun_Id <-- starfunC_Id
  6724   starfun_approx <-- starfun{Nat,CR}_approx
  6725   starfun_capprox <-- starfun{C,RC}_capprox
  6726   starfun_abs <-- starfunNat_rabs
  6727   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  6728   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  6729   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  6730   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  6731   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  6732   starfun_add_approx <-- starfunCR_add_approx
  6733   starfun_inverse_inverse <-- starfunC_inverse_inverse
  6734   starfun_divide <-- starfun{C,CR,RC}_divide
  6735   starfun_n <-- starfun{Nat,C}_n
  6736   starfun_n_mult <-- starfun{Nat,C}_n_mult
  6737   starfun_n_add <-- starfun{Nat,C}_n_add
  6738   starfun_n_add_minus <-- starfunNat_n_add_minus
  6739   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  6740   starfun_n_minus <-- starfun{Nat,C}_n_minus
  6741   starfun_n_eq <-- starfun{Nat,C}_n_eq
  6742 
  6743   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  6744   star_n_minus <-- {hypreal,hcomplex}_minus
  6745   star_n_diff <-- {hypreal,hcomplex}_diff
  6746   star_n_mult <-- {hypreal,hcomplex}_mult
  6747   star_n_inverse <-- {hypreal,hcomplex}_inverse
  6748   star_n_le <-- {hypreal,hypnat}_le
  6749   star_n_less <-- {hypreal,hypnat}_less
  6750   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  6751   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  6752   star_n_abs <-- hypreal_hrabs
  6753   star_n_divide <-- hcomplex_divide
  6754 
  6755   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  6756   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  6757   star_of_diff <-- hypreal_of_real_diff
  6758   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  6759   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  6760   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  6761   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  6762   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  6763   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  6764   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  6765   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  6766   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  6767   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  6768   star_of_number_of <-- {hypreal,hcomplex}_number_of
  6769   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  6770   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  6771   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  6772   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  6773   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  6774   star_of_power <-- hypreal_of_real_power
  6775   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  6776 
  6777 * Hyperreal: new method "transfer" that implements the transfer
  6778 principle of nonstandard analysis. With a subgoal that mentions
  6779 nonstandard types like "'a star", the command "apply transfer"
  6780 replaces it with an equivalent one that mentions only standard types.
  6781 To be successful, all free variables must have standard types; non-
  6782 standard variables must have explicit universal quantifiers.
  6783 
  6784 * Hyperreal: A theory of Taylor series.
  6785 
  6786 
  6787 *** HOLCF ***
  6788 
  6789 * Discontinued special version of 'constdefs' (which used to support
  6790 continuous functions) in favor of the general Pure one with full
  6791 type-inference.
  6792 
  6793 * New simplification procedure for solving continuity conditions; it
  6794 is much faster on terms with many nested lambda abstractions (cubic
  6795 instead of exponential time).
  6796 
  6797 * New syntax for domain package: selector names are now optional.
  6798 Parentheses should be omitted unless argument is lazy, for example:
  6799 
  6800   domain 'a stream = cons "'a" (lazy "'a stream")
  6801 
  6802 * New command 'fixrec' for defining recursive functions with pattern
  6803 matching; defining multiple functions with mutual recursion is also
  6804 supported.  Patterns may include the constants cpair, spair, up, sinl,
  6805 sinr, or any data constructor defined by the domain package. The given
  6806 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  6807 syntax and examples.
  6808 
  6809 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  6810 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  6811 but the proof obligation additionally includes an admissibility
  6812 requirement. The packages generate instances of class cpo or pcpo,
  6813 with continuity and strictness theorems for Rep and Abs.
  6814 
  6815 * HOLCF: Many theorems have been renamed according to a more standard naming
  6816 scheme (INCOMPATIBILITY):
  6817 
  6818   foo_inject:  "foo$x = foo$y ==> x = y"
  6819   foo_eq:      "(foo$x = foo$y) = (x = y)"
  6820   foo_less:    "(foo$x << foo$y) = (x << y)"
  6821   foo_strict:  "foo$UU = UU"
  6822   foo_defined: "... ==> foo$x ~= UU"
  6823   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  6824 
  6825 
  6826 *** ZF ***
  6827 
  6828 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  6829 including the First Isomorphism Theorem (on quotienting by the kernel
  6830 of a homomorphism).
  6831 
  6832 * ZF/Simplifier: install second copy of type solver that actually
  6833 makes use of TC rules declared to Isar proof contexts (or locales);
  6834 the old version is still required for ML proof scripts.
  6835 
  6836 
  6837 *** Cube ***
  6838 
  6839 * Converted to Isar theory format; use locales instead of axiomatic
  6840 theories.
  6841 
  6842 
  6843 *** ML ***
  6844 
  6845 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  6846 for ||>, ||>>, |>>,
  6847 
  6848 * Pure/library.ML no longer defines its own option datatype, but uses
  6849 that of the SML basis, which has constructors NONE and SOME instead of
  6850 None and Some, as well as exception Option.Option instead of OPTION.
  6851 The functions the, if_none, is_some, is_none have been adapted
  6852 accordingly, while Option.map replaces apsome.
  6853 
  6854 * Pure/library.ML: the exception LIST has been given up in favour of
  6855 the standard exceptions Empty and Subscript, as well as
  6856 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6857 superceded by the standard hd and tl functions etc.
  6858 
  6859 A number of basic list functions are no longer exported to the ML
  6860 toplevel, as they are variants of predefined functions.  The following
  6861 suggests how one can translate existing code:
  6862 
  6863     rev_append xs ys = List.revAppend (xs, ys)
  6864     nth_elem (i, xs) = List.nth (xs, i)
  6865     last_elem xs = List.last xs
  6866     flat xss = List.concat xss
  6867     seq fs = List.app fs
  6868     partition P xs = List.partition P xs
  6869     mapfilter f xs = List.mapPartial f xs
  6870 
  6871 * Pure/library.ML: several combinators for linear functional
  6872 transformations, notably reverse application and composition:
  6873 
  6874   x |> f                f #> g
  6875   (x, y) |-> f          f #-> g
  6876 
  6877 * Pure/library.ML: introduced/changed precedence of infix operators:
  6878 
  6879   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6880   infix 2 ?;
  6881   infix 3 o oo ooo oooo;
  6882   infix 4 ~~ upto downto;
  6883 
  6884 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6885 infix operators.
  6886 
  6887 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6888 fold_map support linear functional transformations and nesting.  For
  6889 example:
  6890 
  6891   fold f [x1, ..., xN] y =
  6892     y |> f x1 |> ... |> f xN
  6893 
  6894   (fold o fold) f [xs1, ..., xsN] y =
  6895     y |> fold f xs1 |> ... |> fold f xsN
  6896 
  6897   fold f [x1, ..., xN] =
  6898     f x1 #> ... #> f xN
  6899 
  6900   (fold o fold) f [xs1, ..., xsN] =
  6901     fold f xs1 #> ... #> fold f xsN
  6902 
  6903 * Pure/library.ML: the following selectors on type 'a option are
  6904 available:
  6905 
  6906   the:               'a option -> 'a  (*partial*)
  6907   these:             'a option -> 'a  where 'a = 'b list
  6908   the_default: 'a -> 'a option -> 'a
  6909   the_list:          'a option -> 'a list
  6910 
  6911 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6912 basic operations for association lists, following natural argument
  6913 order; moreover the explicit equality predicate passed here avoids
  6914 potentially expensive polymorphic runtime equality checks.
  6915 The old functions may be expressed as follows:
  6916 
  6917   assoc = uncurry (AList.lookup (op =))
  6918   assocs = these oo AList.lookup (op =)
  6919   overwrite = uncurry (AList.update (op =)) o swap
  6920 
  6921 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6922 
  6923   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6924   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6925 
  6926 replacing make_keylist and keyfilter (occassionally used)
  6927 Naive rewrites:
  6928 
  6929   make_keylist = AList.make
  6930   keyfilter = AList.find (op =)
  6931 
  6932 * eq_fst and eq_snd now take explicit equality parameter, thus
  6933   avoiding eqtypes. Naive rewrites:
  6934 
  6935     eq_fst = eq_fst (op =)
  6936     eq_snd = eq_snd (op =)
  6937 
  6938 * Removed deprecated apl and apr (rarely used).
  6939   Naive rewrites:
  6940 
  6941     apl (n, op) =>>= curry op n
  6942     apr (op, m) =>>= fn n => op (n, m)
  6943 
  6944 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6945 provides a reasonably efficient light-weight implementation of sets as
  6946 lists.
  6947 
  6948 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6949 few new operations; existing lookup and update are now curried to
  6950 follow natural argument order (for use with fold etc.);
  6951 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6952 
  6953 * Pure/General: output via the Isabelle channels of
  6954 writeln/warning/error etc. is now passed through Output.output, with a
  6955 hook for arbitrary transformations depending on the print_mode
  6956 (cf. Output.add_mode -- the first active mode that provides a output
  6957 function wins).  Already formatted output may be embedded into further
  6958 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6959 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6960 accommodate easy composition of diagnostic messages etc.  Programmers
  6961 rarely need to care about Output.output or Output.raw at all, with
  6962 some notable exceptions: Output.output is required when bypassing the
  6963 standard channels (writeln etc.), or in token translations to produce
  6964 properly formatted results; Output.raw is required when capturing
  6965 already output material that will eventually be presented to the user
  6966 a second time.  For the default print mode, both Output.output and
  6967 Output.raw have no effect.
  6968 
  6969 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6970 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6971 cumulative results are displayed at the end of a batch session.
  6972 
  6973 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6974 replaced by File.platform_path and File.shell_path (with appropriate
  6975 hooks).  This provides a clean interface for unusual systems where the
  6976 internal and external process view of file names are different.
  6977 
  6978 * Pure: more efficient orders for basic syntactic entities: added
  6979 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6980 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6981 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6982 orders now -- potential INCOMPATIBILITY for code that depends on a
  6983 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6984 Library.sort_strings on result).
  6985 
  6986 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6987 fold_types traverse types/terms from left to right, observing natural
  6988 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6989 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6990 
  6991 * Pure: name spaces have been refined, with significant changes of the
  6992 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6993 to extern(_table).  The plain name entry path is superceded by a
  6994 general 'naming' context, which also includes the 'policy' to produce
  6995 a fully qualified name and external accesses of a fully qualified
  6996 name; NameSpace.extend is superceded by context dependent
  6997 Sign.declare_name.  Several theory and proof context operations modify
  6998 the naming context.  Especially note Theory.restore_naming and
  6999 ProofContext.restore_naming to get back to a sane state; note that
  7000 Theory.add_path is no longer sufficient to recover from
  7001 Theory.absolute_path in particular.
  7002 
  7003 * Pure: new flags short_names (default false) and unique_names
  7004 (default true) for controlling output of qualified names.  If
  7005 short_names is set, names are printed unqualified.  If unique_names is
  7006 reset, the name prefix is reduced to the minimum required to achieve
  7007 the original result when interning again, even if there is an overlap
  7008 with earlier declarations.
  7009 
  7010 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  7011 now 'extend', and 'merge' gets an additional Pretty.pp argument
  7012 (useful for printing error messages).  INCOMPATIBILITY.
  7013 
  7014 * Pure: major reorganization of the theory context.  Type Sign.sg and
  7015 Theory.theory are now identified, referring to the universal
  7016 Context.theory (see Pure/context.ML).  Actual signature and theory
  7017 content is managed as theory data.  The old code and interfaces were
  7018 spread over many files and structures; the new arrangement introduces
  7019 considerable INCOMPATIBILITY to gain more clarity:
  7020 
  7021   Context -- theory management operations (name, identity, inclusion,
  7022     parents, ancestors, merge, etc.), plus generic theory data;
  7023 
  7024   Sign -- logical signature and syntax operations (declaring consts,
  7025     types, etc.), plus certify/read for common entities;
  7026 
  7027   Theory -- logical theory operations (stating axioms, definitions,
  7028     oracles), plus a copy of logical signature operations (consts,
  7029     types, etc.); also a few basic management operations (Theory.copy,
  7030     Theory.merge, etc.)
  7031 
  7032 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  7033 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  7034 for convenience -- they merely return the theory.
  7035 
  7036 * Pure: type Type.tsig is superceded by theory in most interfaces.
  7037 
  7038 * Pure: the Isar proof context type is already defined early in Pure
  7039 as Context.proof (note that ProofContext.context and Proof.context are
  7040 aliases, where the latter is the preferred name).  This enables other
  7041 Isabelle components to refer to that type even before Isar is present.
  7042 
  7043 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  7044 typeK, constK, axiomK, oracleK), but provide explicit operations for
  7045 any of these kinds.  For example, Sign.intern typeK is now
  7046 Sign.intern_type, Theory.hide_space Sign.typeK is now
  7047 Theory.hide_types.  Also note that former
  7048 Theory.hide_classes/types/consts are now
  7049 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  7050 internalize their arguments!  INCOMPATIBILITY.
  7051 
  7052 * Pure: get_thm interface (of PureThy and ProofContext) expects
  7053 datatype thmref (with constructors Name and NameSelection) instead of
  7054 plain string -- INCOMPATIBILITY;
  7055 
  7056 * Pure: cases produced by proof methods specify options, where NONE
  7057 means to remove case bindings -- INCOMPATIBILITY in
  7058 (RAW_)METHOD_CASES.
  7059 
  7060 * Pure: the following operations retrieve axioms or theorems from a
  7061 theory node or theory hierarchy, respectively:
  7062 
  7063   Theory.axioms_of: theory -> (string * term) list
  7064   Theory.all_axioms_of: theory -> (string * term) list
  7065   PureThy.thms_of: theory -> (string * thm) list
  7066   PureThy.all_thms_of: theory -> (string * thm) list
  7067 
  7068 * Pure: print_tac now outputs the goal through the trace channel.
  7069 
  7070 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  7071 Reference Toplevel.debug (default false) controls detailed printing
  7072 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  7073 controls execution profiling -- set to 1 for time and 2 for space
  7074 (both increase the runtime).
  7075 
  7076 * Isar session: The initial use of ROOT.ML is now always timed,
  7077 i.e. the log will show the actual process times, in contrast to the
  7078 elapsed wall-clock time that the outer shell wrapper produces.
  7079 
  7080 * Simplifier: improved handling of bound variables (nameless
  7081 representation, avoid allocating new strings).  Simprocs that invoke
  7082 the Simplifier recursively should use Simplifier.inherit_bounds to
  7083 avoid local name clashes.  Failure to do so produces warnings
  7084 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  7085 for further details.
  7086 
  7087 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  7088 bindings for all theorems stored within a given theory; this may help
  7089 in porting non-Isar theories to Isar ones, while keeping ML proof
  7090 scripts for the time being.
  7091 
  7092 * ML operator HTML.with_charset specifies the charset begin used for
  7093 generated HTML files.  For example:
  7094 
  7095   HTML.with_charset "utf-8" use_thy "Hebrew";
  7096   HTML.with_charset "utf-8" use_thy "Chinese";
  7097 
  7098 
  7099 *** System ***
  7100 
  7101 * Allow symlinks to all proper Isabelle executables (Isabelle,
  7102 isabelle, isatool etc.).
  7103 
  7104 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  7105 isatool doc, isatool mkdir, display_drafts etc.).
  7106 
  7107 * isatool usedir: option -f allows specification of the ML file to be
  7108 used by Isabelle; default is ROOT.ML.
  7109 
  7110 * New isatool version outputs the version identifier of the Isabelle
  7111 distribution being used.
  7112 
  7113 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  7114 (containing Boolean satisfiability problems) into Isabelle/HOL
  7115 theories.
  7116 
  7117 
  7118 
  7119 New in Isabelle2004 (April 2004)
  7120 --------------------------------
  7121 
  7122 *** General ***
  7123 
  7124 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  7125   Replaces linorder.ML.
  7126 
  7127 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  7128   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  7129   (\<a>...\<z>), are now considered normal letters, and can therefore
  7130   be used anywhere where an ASCII letter (a...zA...Z) has until
  7131   now. COMPATIBILITY: This obviously changes the parsing of some
  7132   terms, especially where a symbol has been used as a binder, say
  7133   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  7134   as an identifier.  Fix it by inserting a space around former
  7135   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  7136   existing theory and ML files.
  7137 
  7138 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  7139 
  7140 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  7141   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  7142   a normal (but invisible) letter. For multiple letter subscripts repeat
  7143   \<^isub> like this: x\<^isub>1\<^isub>2.
  7144 
  7145 * Pure: There are now sub-/superscripts that can span more than one
  7146   character. Text between \<^bsub> and \<^esub> is set in subscript in
  7147   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  7148   superscript. The new control characters are not identifier parts.
  7149 
  7150 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  7151   content of "..." to the latex file instead of \isacntrl... . The "..."
  7152   may consist of any printable characters excluding the end bracket >.
  7153 
  7154 * Pure: Using new Isar command "finalconsts" (or the ML functions
  7155   Theory.add_finals or Theory.add_finals_i) it is now possible to
  7156   declare constants "final", which prevents their being given a definition
  7157   later.  It is useful for constants whose behaviour is fixed axiomatically
  7158   rather than definitionally, such as the meta-logic connectives.
  7159 
  7160 * Pure: 'instance' now handles general arities with general sorts
  7161   (i.e. intersections of classes),
  7162 
  7163 * Presentation: generated HTML now uses a CSS style sheet to make layout
  7164   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  7165   It can be changed to alter the colors/layout of generated pages.
  7166 
  7167 
  7168 *** Isar ***
  7169 
  7170 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  7171   cut_tac, subgoal_tac and thin_tac:
  7172   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  7173     locales are no longer forced to write Isar proof scripts.
  7174     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  7175     emulations.
  7176   - INCOMPATIBILITY: names of variables to be instantiated may no
  7177     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  7178     This is consistent with the instantiation attribute "where".
  7179 
  7180 * Attributes "where" and "of":
  7181   - Now take type variables of instantiated theorem into account when reading
  7182     the instantiation string.  This fixes a bug that caused instantiated
  7183     theorems to have too special types in some circumstances.
  7184   - "where" permits explicit instantiations of type variables.
  7185 
  7186 * Calculation commands "moreover" and "also" no longer interfere with
  7187   current facts ("this"), admitting arbitrary combinations with "then"
  7188   and derived forms.
  7189 
  7190 * Locales:
  7191   - Goal statements involving the context element "includes" no longer
  7192     generate theorems with internal delta predicates (those ending on
  7193     "_axioms") in the premise.
  7194     Resolve particular premise with <locale>.intro to obtain old form.
  7195   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  7196     specification and "includes" elements in goal statement.
  7197   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  7198     [intro?] and [elim?] (respectively) by default.
  7199   - Experimental command for instantiation of locales in proof contexts:
  7200         instantiate <label>[<attrs>]: <loc>
  7201     Instantiates locale <loc> and adds all its theorems to the current context
  7202     taking into account their attributes.  Label and attrs are optional
  7203     modifiers, like in theorem declarations.  If present, names of
  7204     instantiated theorems are qualified with <label>, and the attributes
  7205     <attrs> are applied after any attributes these theorems might have already.
  7206       If the locale has assumptions, a chained fact of the form
  7207     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  7208     are derived.  The command does not support old-style locales declared
  7209     with "locale (open)".
  7210       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  7211 
  7212 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  7213   (Isar) contexts.
  7214 
  7215 
  7216 *** HOL ***
  7217 
  7218 * Proof import: new image HOL4 contains the imported library from
  7219   the HOL4 system with about 2500 theorems. It is imported by
  7220   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  7221   can be used like any other Isabelle image.  See
  7222   HOL/Import/HOL/README for more information.
  7223 
  7224 * Simplifier:
  7225   - Much improved handling of linear and partial orders.
  7226     Reasoners for linear and partial orders are set up for type classes
  7227     "linorder" and "order" respectively, and are added to the default simpset
  7228     as solvers.  This means that the simplifier can build transitivity chains
  7229     to solve goals from the assumptions.
  7230   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  7231     of blast or auto after simplification become unnecessary because the goal
  7232     is solved by simplification already.
  7233 
  7234 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  7235     all proved in axiomatic type classes for semirings, rings and fields.
  7236 
  7237 * Numerics:
  7238   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  7239     now formalized using the Ring_and_Field theory mentioned above.
  7240   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  7241     than before, because now they are set up once in a generic manner.
  7242   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  7243     Look for the general versions in Ring_and_Field (and Power if they concern
  7244     exponentiation).
  7245 
  7246 * Type "rat" of the rational numbers is now available in HOL-Complex.
  7247 
  7248 * Records:
  7249   - Record types are now by default printed with their type abbreviation
  7250     instead of the list of all field types. This can be configured via
  7251     the reference "print_record_type_abbr".
  7252   - Simproc "record_upd_simproc" for simplification of multiple updates added
  7253     (not enabled by default).
  7254   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  7255     EX x. x = sel r to True (not enabled by default).
  7256   - Tactic "record_split_simp_tac" to split and simplify records added.
  7257 
  7258 * 'specification' command added, allowing for definition by
  7259   specification.  There is also an 'ax_specification' command that
  7260   introduces the new constants axiomatically.
  7261 
  7262 * arith(_tac) is now able to generate counterexamples for reals as well.
  7263 
  7264 * HOL-Algebra: new locale "ring" for non-commutative rings.
  7265 
  7266 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  7267   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  7268 
  7269 * HOL-Matrix: a first theory for matrices in HOL with an application of
  7270   matrix theory to linear programming.
  7271 
  7272 * Unions and Intersections:
  7273   The latex output syntax of UN and INT has been changed
  7274   from "\Union x \in A. B" to "\Union_{x \in A} B"
  7275   i.e. the index formulae has become a subscript.
  7276   Similarly for "\Union x. B", and for \Inter instead of \Union.
  7277 
  7278 * Unions and Intersections over Intervals:
  7279   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  7280   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  7281   like in normal math, and corresponding versions for < and for intersection.
  7282 
  7283 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  7284   lexicographic dictonary ordering has been added as "lexord".
  7285 
  7286 * ML: the legacy theory structures Int and List have been removed. They had
  7287   conflicted with ML Basis Library structures having the same names.
  7288 
  7289 * 'refute' command added to search for (finite) countermodels.  Only works
  7290   for a fragment of HOL.  The installation of an external SAT solver is
  7291   highly recommended.  See "HOL/Refute.thy" for details.
  7292 
  7293 * 'quickcheck' command: Allows to find counterexamples by evaluating
  7294   formulae under an assignment of free variables to random values.
  7295   In contrast to 'refute', it can deal with inductive datatypes,
  7296   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  7297   for examples.
  7298 
  7299 
  7300 *** HOLCF ***
  7301 
  7302 * Streams now come with concatenation and are part of the HOLCF image
  7303 
  7304 
  7305 
  7306 New in Isabelle2003 (May 2003)
  7307 ------------------------------
  7308 
  7309 *** General ***
  7310 
  7311 * Provers/simplifier:
  7312 
  7313   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  7314     Assumptions are now subject to complete mutual simplification,
  7315     not just from left to right. The simplifier now preserves
  7316     the order of assumptions.
  7317 
  7318     Potential INCOMPATIBILITY:
  7319 
  7320     -- simp sometimes diverges where the old version did
  7321        not, e.g. invoking simp on the goal
  7322 
  7323         [| P (f x); y = x; f x = f y |] ==> Q
  7324 
  7325        now gives rise to the infinite reduction sequence
  7326 
  7327         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  7328 
  7329        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  7330        kind of problem.
  7331 
  7332     -- Tactics combining classical reasoner and simplification (such as auto)
  7333        are also affected by this change, because many of them rely on
  7334        simp. They may sometimes diverge as well or yield a different numbers
  7335        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  7336        in case of problems. Sometimes subsequent calls to the classical
  7337        reasoner will fail because a preceeding call to the simplifier too
  7338        eagerly simplified the goal, e.g. deleted redundant premises.
  7339 
  7340   - The simplifier trace now shows the names of the applied rewrite rules
  7341 
  7342   - You can limit the number of recursive invocations of the simplifier
  7343     during conditional rewriting (where the simplifie tries to solve the
  7344     conditions before applying the rewrite rule):
  7345     ML "simp_depth_limit := n"
  7346     where n is an integer. Thus you can force termination where previously
  7347     the simplifier would diverge.
  7348 
  7349   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  7350 
  7351   - No longer aborts on failed congruence proof.  Instead, the
  7352     congruence is ignored.
  7353 
  7354 * Pure: New generic framework for extracting programs from constructive
  7355   proofs. See HOL/Extraction.thy for an example instantiation, as well
  7356   as HOL/Extraction for some case studies.
  7357 
  7358 * Pure: The main goal of the proof state is no longer shown by default, only
  7359 the subgoals. This behaviour is controlled by a new flag.
  7360    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  7361 (ML: Proof.show_main_goal).
  7362 
  7363 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  7364 rules whose conclusion matches subgoal 1:
  7365       PG menu: Isabelle/Isar -> Show me -> matching rules
  7366 The rules are ordered by how closely they match the subgoal.
  7367 In particular, rules that solve a subgoal outright are displayed first
  7368 (or rather last, the way they are printed).
  7369 (ML: ProofGeneral.print_intros())
  7370 
  7371 * Pure: New flag trace_unify_fail causes unification to print
  7372 diagnostic information (PG: in trace buffer) when it fails. This is
  7373 useful for figuring out why single step proofs like rule, erule or
  7374 assumption failed.
  7375 
  7376 * Pure: Locale specifications now produce predicate definitions
  7377 according to the body of text (covering assumptions modulo local
  7378 definitions); predicate "loc_axioms" covers newly introduced text,
  7379 while "loc" is cumulative wrt. all included locale expressions; the
  7380 latter view is presented only on export into the global theory
  7381 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  7382 on the old view without predicates;
  7383 
  7384 * Pure: predefined locales "var" and "struct" are useful for sharing
  7385 parameters (as in CASL, for example); just specify something like
  7386 ``var x + var y + struct M'' as import;
  7387 
  7388 * Pure: improved thms_containing: proper indexing of facts instead of
  7389 raw theorems; check validity of results wrt. current name space;
  7390 include local facts of proof configuration (also covers active
  7391 locales), cover fixed variables in index; may use "_" in term
  7392 specification; an optional limit for the number of printed facts may
  7393 be given (the default is 40);
  7394 
  7395 * Pure: disallow duplicate fact bindings within new-style theory files
  7396 (batch-mode only);
  7397 
  7398 * Provers: improved induct method: assumptions introduced by case
  7399 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  7400 the goal statement); "foo" still refers to all facts collectively;
  7401 
  7402 * Provers: the function blast.overloaded has been removed: all constants
  7403 are regarded as potentially overloaded, which improves robustness in exchange
  7404 for slight decrease in efficiency;
  7405 
  7406 * Provers/linorder: New generic prover for transitivity reasoning over
  7407 linear orders.  Note: this prover is not efficient!
  7408 
  7409 * Isar: preview of problems to finish 'show' now produce an error
  7410 rather than just a warning (in interactive mode);
  7411 
  7412 
  7413 *** HOL ***
  7414 
  7415 * arith(_tac)
  7416 
  7417  - Produces a counter example if it cannot prove a goal.
  7418    Note that the counter example may be spurious if the goal is not a formula
  7419    of quantifier-free linear arithmetic.
  7420    In ProofGeneral the counter example appears in the trace buffer.
  7421 
  7422  - Knows about div k and mod k where k is a numeral of type nat or int.
  7423 
  7424  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  7425    linear arithmetic fails. This takes account of quantifiers and divisibility.
  7426    Presburger arithmetic can also be called explicitly via presburger(_tac).
  7427 
  7428 * simp's arithmetic capabilities have been enhanced a bit: it now
  7429 takes ~= in premises into account (by performing a case split);
  7430 
  7431 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  7432 are distributed over a sum of terms;
  7433 
  7434 * New tactic "trans_tac" and method "trans" instantiate
  7435 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  7436 "<=", "<" and "=").
  7437 
  7438 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  7439 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  7440 
  7441 * 'typedef' command has new option "open" to suppress the set
  7442 definition;
  7443 
  7444 * functions Min and Max on finite sets have been introduced (theory
  7445 Finite_Set);
  7446 
  7447 * attribute [symmetric] now works for relations as well; it turns
  7448 (x,y) : R^-1 into (y,x) : R, and vice versa;
  7449 
  7450 * induct over a !!-quantified statement (say !!x1..xn):
  7451   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  7452 
  7453 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  7454 %x. None. Warning: empty_def now refers to the previously hidden definition
  7455 of the empty set.
  7456 
  7457 * Algebra: formalization of classical algebra.  Intended as base for
  7458 any algebraic development in Isabelle.  Currently covers group theory
  7459 (up to Sylow's theorem) and ring theory (Universal Property of
  7460 Univariate Polynomials).  Contributions welcome;
  7461 
  7462 * GroupTheory: deleted, since its material has been moved to Algebra;
  7463 
  7464 * Complex: new directory of the complex numbers with numeric constants,
  7465 nonstandard complex numbers, and some complex analysis, standard and
  7466 nonstandard (Jacques Fleuriot);
  7467 
  7468 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  7469 
  7470 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  7471 Fleuriot);
  7472 
  7473 * Real/HahnBanach: updated and adapted to locales;
  7474 
  7475 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  7476 Gray and Kramer);
  7477 
  7478 * UNITY: added the Meier-Sanders theory of progress sets;
  7479 
  7480 * MicroJava: bytecode verifier and lightweight bytecode verifier
  7481 as abstract algorithms, instantiated to the JVM;
  7482 
  7483 * Bali: Java source language formalization. Type system, operational
  7484 semantics, axiomatic semantics. Supported language features:
  7485 classes, interfaces, objects,virtual methods, static methods,
  7486 static/instance fields, arrays, access modifiers, definite
  7487 assignment, exceptions.
  7488 
  7489 
  7490 *** ZF ***
  7491 
  7492 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  7493 universe, etc.);
  7494 
  7495 * Main ZF: virtually all theories converted to new-style format;
  7496 
  7497 
  7498 *** ML ***
  7499 
  7500 * Pure: Tactic.prove provides sane interface for internal proofs;
  7501 omits the infamous "standard" operation, so this is more appropriate
  7502 than prove_goalw_cterm in many situations (e.g. in simprocs);
  7503 
  7504 * Pure: improved error reporting of simprocs;
  7505 
  7506 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  7507 up simprocs;
  7508 
  7509 
  7510 *** Document preparation ***
  7511 
  7512 * uses \par instead of \\ for line breaks in theory text. This may
  7513 shift some page breaks in large documents. To get the old behaviour
  7514 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  7515 
  7516 * minimized dependencies of isabelle.sty and isabellesym.sty on
  7517 other packages
  7518 
  7519 * \<euro> now needs package babel/greek instead of marvosym (which
  7520 broke \Rightarrow)
  7521 
  7522 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  7523 textcomp package)
  7524 
  7525 
  7526 
  7527 New in Isabelle2002 (March 2002)
  7528 --------------------------------
  7529 
  7530 *** Document preparation ***
  7531 
  7532 * greatly simplified document preparation setup, including more
  7533 graceful interpretation of isatool usedir -i/-d/-D options, and more
  7534 instructive isatool mkdir; users should basically be able to get
  7535 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  7536 users may run a separate document processing stage manually like this:
  7537 "isatool usedir -D output HOL Test && isatool document Test/output";
  7538 
  7539 * theory dependency graph may now be incorporated into documents;
  7540 isatool usedir -g true will produce session_graph.eps/.pdf for use
  7541 with \includegraphics of LaTeX;
  7542 
  7543 * proper spacing of consecutive markup elements, especially text
  7544 blocks after section headings;
  7545 
  7546 * support bold style (for single symbols only), input syntax is like
  7547 this: "\<^bold>\<alpha>" or "\<^bold>A";
  7548 
  7549 * \<bullet> is now output as bold \cdot by default, which looks much
  7550 better in printed text;
  7551 
  7552 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  7553 note that these symbols are currently unavailable in Proof General /
  7554 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  7555 
  7556 * isatool latex no longer depends on changed TEXINPUTS, instead
  7557 isatool document copies the Isabelle style files to the target
  7558 location;
  7559 
  7560 
  7561 *** Isar ***
  7562 
  7563 * Pure/Provers: improved proof by cases and induction;
  7564   - 'case' command admits impromptu naming of parameters (such as
  7565     "case (Suc n)");
  7566   - 'induct' method divinates rule instantiation from the inductive
  7567     claim; no longer requires excessive ?P bindings for proper
  7568     instantiation of cases;
  7569   - 'induct' method properly enumerates all possibilities of set/type
  7570     rules; as a consequence facts may be also passed through *type*
  7571     rules without further ado;
  7572   - 'induct' method now derives symbolic cases from the *rulified*
  7573     rule (before it used to rulify cases stemming from the internal
  7574     atomized version); this means that the context of a non-atomic
  7575     statement becomes is included in the hypothesis, avoiding the
  7576     slightly cumbersome show "PROP ?case" form;
  7577   - 'induct' may now use elim-style induction rules without chaining
  7578     facts, using ``missing'' premises from the goal state; this allows
  7579     rules stemming from inductive sets to be applied in unstructured
  7580     scripts, while still benefitting from proper handling of non-atomic
  7581     statements; NB: major inductive premises need to be put first, all
  7582     the rest of the goal is passed through the induction;
  7583   - 'induct' proper support for mutual induction involving non-atomic
  7584     rule statements (uses the new concept of simultaneous goals, see
  7585     below);
  7586   - append all possible rule selections, but only use the first
  7587     success (no backtracking);
  7588   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  7589   - undeclared rule case names default to numbers 1, 2, 3, ...;
  7590   - added 'print_induct_rules' (covered by help item in recent Proof
  7591     General versions);
  7592   - moved induct/cases attributes to Pure, methods to Provers;
  7593   - generic method setup instantiated for FOL and HOL;
  7594 
  7595 * Pure: support multiple simultaneous goal statements, for example
  7596 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  7597 meta-level mechanism, this acts as if several individual goals had
  7598 been stated separately; in particular common proof methods need to be
  7599 repeated in order to cover all claims; note that a single elimination
  7600 step is *not* sufficient to establish the two conjunctions, so this
  7601 fails:
  7602 
  7603   assume "A & B" then have A and B ..   (*".." fails*)
  7604 
  7605 better use "obtain" in situations as above; alternative refer to
  7606 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  7607 
  7608 * Pure: proper integration with ``locales''; unlike the original
  7609 version by Florian Kammller, Isar locales package high-level proof
  7610 contexts rather than raw logical ones (e.g. we admit to include
  7611 attributes everywhere); operations on locales include merge and
  7612 rename; support for implicit arguments (``structures''); simultaneous
  7613 type-inference over imports and text; see also HOL/ex/Locales.thy for
  7614 some examples;
  7615 
  7616 * Pure: the following commands have been ``localized'', supporting a
  7617 target locale specification "(in name)": 'lemma', 'theorem',
  7618 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  7619 stored both within the locale and at the theory level (exported and
  7620 qualified by the locale name);
  7621 
  7622 * Pure: theory goals may now be specified in ``long'' form, with
  7623 ad-hoc contexts consisting of arbitrary locale elements. for example
  7624 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  7625 definitions may be given, too); the result is a meta-level rule with
  7626 the context elements being discharged in the obvious way;
  7627 
  7628 * Pure: new proof command 'using' allows to augment currently used
  7629 facts after a goal statement ('using' is syntactically analogous to
  7630 'apply', but acts on the goal's facts only); this allows chained facts
  7631 to be separated into parts given before and after a claim, as in
  7632 ``from a and b have C using d and e <proof>'';
  7633 
  7634 * Pure: renamed "antecedent" case to "rule_context";
  7635 
  7636 * Pure: new 'judgment' command records explicit information about the
  7637 object-logic embedding (used by several tools internally); no longer
  7638 use hard-wired "Trueprop";
  7639 
  7640 * Pure: added 'corollary' command;
  7641 
  7642 * Pure: fixed 'token_translation' command;
  7643 
  7644 * Pure: removed obsolete 'exported' attribute;
  7645 
  7646 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  7647 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  7648 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  7649 
  7650 * Pure: method 'atomize' presents local goal premises as object-level
  7651 statements (atomic meta-level propositions); setup controlled via
  7652 rewrite rules declarations of 'atomize' attribute; example
  7653 application: 'induct' method with proper rule statements in improper
  7654 proof *scripts*;
  7655 
  7656 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  7657 now consider the syntactic context of assumptions, giving a better
  7658 chance to get type-inference of the arguments right (this is
  7659 especially important for locales);
  7660 
  7661 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  7662 mode;
  7663 
  7664 * Pure/obtain: the formal conclusion "thesis", being marked as
  7665 ``internal'', may no longer be reference directly in the text;
  7666 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  7667 situations;
  7668 
  7669 * Pure: generic 'sym' attribute which declares a rule both as pure
  7670 'elim?' and for the 'symmetric' operation;
  7671 
  7672 * Pure: marginal comments ``--'' may now occur just anywhere in the
  7673 text; the fixed correlation with particular command syntax has been
  7674 discontinued;
  7675 
  7676 * Pure: new method 'rules' is particularly well-suited for proof
  7677 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  7678 but often produces more compact proof terms with less detours;
  7679 
  7680 * Pure/Provers/classical: simplified integration with pure rule
  7681 attributes and methods; the classical "intro?/elim?/dest?"
  7682 declarations coincide with the pure ones; the "rule" method no longer
  7683 includes classically swapped intros; "intro" and "elim" methods no
  7684 longer pick rules from the context; also got rid of ML declarations
  7685 AddXIs/AddXEs/AddXDs; all of this has some potential for
  7686 INCOMPATIBILITY;
  7687 
  7688 * Provers/classical: attribute 'swapped' produces classical inversions
  7689 of introduction rules;
  7690 
  7691 * Provers/simplifier: 'simplified' attribute may refer to explicit
  7692 rules instead of full simplifier context; 'iff' attribute handles
  7693 conditional rules;
  7694 
  7695 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  7696 
  7697 * HOL: 'recdef' now fails on unfinished automated proofs, use
  7698 "(permissive)" option to recover old behavior;
  7699 
  7700 * HOL: 'inductive' no longer features separate (collective) attributes
  7701 for 'intros' (was found too confusing);
  7702 
  7703 * HOL: properly declared induction rules less_induct and
  7704 wf_induct_rule;
  7705 
  7706 
  7707 *** HOL ***
  7708 
  7709 * HOL: moved over to sane numeral syntax; the new policy is as
  7710 follows:
  7711 
  7712   - 0 and 1 are polymorphic constants, which are defined on any
  7713   numeric type (nat, int, real etc.);
  7714 
  7715   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  7716   binary representation internally;
  7717 
  7718   - type nat has special constructor Suc, and generally prefers Suc 0
  7719   over 1::nat and Suc (Suc 0) over 2::nat;
  7720 
  7721 This change may cause significant problems of INCOMPATIBILITY; here
  7722 are some hints on converting existing sources:
  7723 
  7724   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  7725   entities, so expressions involving "-" (unary or binary minus) need
  7726   to be spaced properly;
  7727 
  7728   - existing occurrences of "1" may need to be constraint "1::nat" or
  7729   even replaced by Suc 0; similar for old "2";
  7730 
  7731   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  7732 
  7733   - remove all special provisions on numerals in proofs;
  7734 
  7735 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  7736 representation (depends on bin_arith_simps in the default context);
  7737 
  7738 * HOL: symbolic syntax for x^2 (numeral 2);
  7739 
  7740 * HOL: the class of all HOL types is now called "type" rather than
  7741 "term"; INCOMPATIBILITY, need to adapt references to this type class
  7742 in axclass/classes, instance/arities, and (usually rare) occurrences
  7743 in typings (of consts etc.); internally the class is called
  7744 "HOL.type", ML programs should refer to HOLogic.typeS;
  7745 
  7746 * HOL/record package improvements:
  7747   - new derived operations "fields" to build a partial record section,
  7748     "extend" to promote a fixed record to a record scheme, and
  7749     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  7750     declared as simp by default;
  7751   - shared operations ("more", "fields", etc.) now need to be always
  7752     qualified) --- potential INCOMPATIBILITY;
  7753   - removed "make_scheme" operations (use "make" with "extend") --
  7754     INCOMPATIBILITY;
  7755   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  7756   - provides cases/induct rules for use with corresponding Isar
  7757     methods (for concrete records, record schemes, concrete more
  7758     parts, and schematic more parts -- in that order);
  7759   - internal definitions directly based on a light-weight abstract
  7760     theory of product types over typedef rather than datatype;
  7761 
  7762 * HOL: generic code generator for generating executable ML code from
  7763 specifications; specific support for HOL constructs such as inductive
  7764 datatypes and sets, as well as recursive functions; can be invoked
  7765 via 'generate_code' theory section;
  7766 
  7767 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  7768 
  7769 * HOL: consolidated and renamed several theories.  In particular:
  7770         Ord.thy has been absorbed into HOL.thy
  7771         String.thy has been absorbed into List.thy
  7772 
  7773 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  7774 (beware of argument permutation!);
  7775 
  7776 * HOL: linorder_less_split superseded by linorder_cases;
  7777 
  7778 * HOL/List: "nodups" renamed to "distinct";
  7779 
  7780 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  7781 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  7782   - Ex_def has changed, now need to use some_eq_ex
  7783 
  7784 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  7785 in this (rare) case use:
  7786 
  7787   delSWrapper "split_all_tac"
  7788   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  7789 
  7790 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  7791 MAY FAIL;
  7792 
  7793 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  7794 Isabelle's type classes, ^ on functions and relations has too general
  7795 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  7796 necessary to attach explicit type constraints;
  7797 
  7798 * HOL/Relation: the prefix name of the infix "O" has been changed from
  7799 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  7800 renamed accordingly (eg "compI" -> "rel_compI").
  7801 
  7802 * HOL: syntax translations now work properly with numerals and records
  7803 expressions;
  7804 
  7805 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  7806 of "lam" -- INCOMPATIBILITY;
  7807 
  7808 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  7809 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  7810 renamed "Product_Type.unit";
  7811 
  7812 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  7813 
  7814 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  7815 the "cases" method);
  7816 
  7817 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  7818 Florian Kammller);
  7819 
  7820 * HOL/IMP: updated and converted to new-style theory format; several
  7821 parts turned into readable document, with proper Isar proof texts and
  7822 some explanations (by Gerwin Klein);
  7823 
  7824 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  7825 
  7826 * HOL-Hyperreal is now a logic image;
  7827 
  7828 
  7829 *** HOLCF ***
  7830 
  7831 * Isar: consts/constdefs supports mixfix syntax for continuous
  7832 operations;
  7833 
  7834 * Isar: domain package adapted to new-style theory format, e.g. see
  7835 HOLCF/ex/Dnat.thy;
  7836 
  7837 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  7838 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  7839 lift.induct_tac, always use UU instead of Undef;
  7840 
  7841 * HOLCF/IMP: updated and converted to new-style theory;
  7842 
  7843 
  7844 *** ZF ***
  7845 
  7846 * Isar: proper integration of logic-specific tools and packages,
  7847 including theory commands '(co)inductive', '(co)datatype',
  7848 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  7849 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7850 
  7851 * theory Main no longer includes AC; for the Axiom of Choice, base
  7852 your theory on Main_ZFC;
  7853 
  7854 * the integer library now covers quotients and remainders, with many
  7855 laws relating division to addition, multiplication, etc.;
  7856 
  7857 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7858 typeless version of the formalism;
  7859 
  7860 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7861 format;
  7862 
  7863 * ZF/Induct: new directory for examples of inductive definitions,
  7864 including theory Multiset for multiset orderings; converted to
  7865 new-style theory format;
  7866 
  7867 * ZF: many new theorems about lists, ordinals, etc.;
  7868 
  7869 
  7870 *** General ***
  7871 
  7872 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7873 variable proof controls level of detail: 0 = no proofs (only oracle
  7874 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7875 also ref manual for further ML interfaces;
  7876 
  7877 * Pure/axclass: removed obsolete ML interface
  7878 goal_subclass/goal_arity;
  7879 
  7880 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7881 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7882 separate tokens, so expressions involving minus need to be spaced
  7883 properly;
  7884 
  7885 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7886 rather than "infixl" or "infixr";
  7887 
  7888 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7889 sort constraint specifications in type inference; e.g. "x::_::foo"
  7890 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7891 type variable);
  7892 
  7893 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7894 control output of nested => (types); the default behavior is
  7895 "type_brackets";
  7896 
  7897 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7898 tokens into AST constants;
  7899 
  7900 * Pure/syntax: prefer later declarations of translations and print
  7901 translation functions; potential INCOMPATIBILITY: need to reverse
  7902 multiple declarations for same syntax element constant;
  7903 
  7904 * Pure/show_hyps reset by default (in accordance to existing Isar
  7905 practice);
  7906 
  7907 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7908 addSafter;
  7909 
  7910 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7911 as well;
  7912 
  7913 * system: tested support for MacOS X; should be able to get Isabelle +
  7914 Proof General to work in a plain Terminal after installing Poly/ML
  7915 (e.g. from the Isabelle distribution area) and GNU bash alone
  7916 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7917 support requires further installations, e.g. from
  7918 http://fink.sourceforge.net/);
  7919 
  7920 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7921 
  7922 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7923 of 40 MB), cf. ML_OPTIONS;
  7924 
  7925 * system: Proof General keywords specification is now part of the
  7926 Isabelle distribution (see etc/isar-keywords.el);
  7927 
  7928 * system: support for persistent Proof General sessions (refrain from
  7929 outdating all loaded theories on startup); user may create writable
  7930 logic images like this: ``isabelle -q HOL Test'';
  7931 
  7932 * system: smart selection of Isabelle process versus Isabelle
  7933 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7934 run both "isabelle" and "Isabelle" even if file names are badly
  7935 damaged (executable inspects the case of the first letter of its own
  7936 name); added separate "isabelle-process" and "isabelle-interface";
  7937 
  7938 * system: refrain from any attempt at filtering input streams; no
  7939 longer support ``8bit'' encoding of old isabelle font, instead proper
  7940 iso-latin characters may now be used; the related isatools
  7941 "symbolinput" and "nonascii" have disappeared as well;
  7942 
  7943 * system: removed old "xterm" interface (the print modes "xterm" and
  7944 "xterm_color" are still available for direct use in a suitable
  7945 terminal);
  7946 
  7947 
  7948 
  7949 New in Isabelle99-2 (February 2001)
  7950 -----------------------------------
  7951 
  7952 *** Overview of INCOMPATIBILITIES ***
  7953 
  7954 * HOL: please note that theories in the Library and elsewhere often use the
  7955 new-style (Isar) format; to refer to their theorems in an ML script you must
  7956 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7957 
  7958 * HOL: inductive package no longer splits induction rule aggressively,
  7959 but only as far as specified by the introductions given; the old
  7960 format may be recovered via ML function complete_split_rule or attribute
  7961 'split_rule (complete)';
  7962 
  7963 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7964 gfp_Tarski to gfp_unfold;
  7965 
  7966 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7967 
  7968 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7969 relation); infix "^^" has been renamed "``"; infix "``" has been
  7970 renamed "`"; "univalent" has been renamed "single_valued";
  7971 
  7972 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7973 operation;
  7974 
  7975 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7976 
  7977 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7978 
  7979 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7980 consequence, it is no longer monotonic wrt. the local goal context
  7981 (which is now passed through the inductive cases);
  7982 
  7983 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7984 \<gg> to \<ggreater>;
  7985 
  7986 
  7987 *** Document preparation ***
  7988 
  7989 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7990 available: are "it" for near math-mode best-style output, "sl" for
  7991 slanted text style, and "tt" for plain type-writer; if no
  7992 \isabellestyle command is given, output is according to slanted
  7993 type-writer);
  7994 
  7995 * support sub/super scripts (for single symbols only), input syntax is
  7996 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7997 
  7998 * some more standard symbols; see Appendix A of the system manual for
  7999 the complete list of symbols defined in isabellesym.sty;
  8000 
  8001 * improved isabelle style files; more abstract symbol implementation
  8002 (should now use \isamath{...} and \isatext{...} in custom symbol
  8003 definitions);
  8004 
  8005 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  8006 state; Note that presentation of goal states does not conform to
  8007 actual human-readable proof documents.  Please do not include goal
  8008 states into document output unless you really know what you are doing!
  8009 
  8010 * proper indentation of antiquoted output with proportional LaTeX
  8011 fonts;
  8012 
  8013 * no_document ML operator temporarily disables LaTeX document
  8014 generation;
  8015 
  8016 * isatool unsymbolize tunes sources for plain ASCII communication;
  8017 
  8018 
  8019 *** Isar ***
  8020 
  8021 * Pure: Isar now suffers initial goal statements to contain unbound
  8022 schematic variables (this does not conform to actual readable proof
  8023 documents, due to unpredictable outcome and non-compositional proof
  8024 checking); users who know what they are doing may use schematic goals
  8025 for Prolog-style synthesis of proven results;
  8026 
  8027 * Pure: assumption method (an implicit finishing) now handles actual
  8028 rules as well;
  8029 
  8030 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  8031 initial goal, declare "that" only as Pure intro (only for single
  8032 steps); the "that" rule assumption may now be involved in implicit
  8033 finishing, thus ".." becomes a feasible for trivial obtains;
  8034 
  8035 * Pure: default proof step now includes 'intro_classes'; thus trivial
  8036 instance proofs may be performed by "..";
  8037 
  8038 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  8039 statements as well;
  8040 
  8041 * Pure: more robust selection of calculational rules;
  8042 
  8043 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  8044 rule (as well as the assumption rule);
  8045 
  8046 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  8047 lemmas, using the graph browser tool;
  8048 
  8049 * Pure: predict failure of "show" in interactive mode;
  8050 
  8051 * Pure: 'thms_containing' now takes actual terms as arguments;
  8052 
  8053 * HOL: improved method 'induct' --- now handles non-atomic goals
  8054 (potential INCOMPATIBILITY); tuned error handling;
  8055 
  8056 * HOL: cases and induct rules now provide explicit hints about the
  8057 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  8058 any remaining facts are inserted into the goal verbatim;
  8059 
  8060 * HOL: local contexts (aka cases) may now contain term bindings as
  8061 well; the 'cases' and 'induct' methods new provide a ?case binding for
  8062 the result to be shown in each case;
  8063 
  8064 * HOL: added 'recdef_tc' command;
  8065 
  8066 * isatool convert assists in eliminating legacy ML scripts;
  8067 
  8068 
  8069 *** HOL ***
  8070 
  8071 * HOL/Library: a collection of generic theories to be used together
  8072 with main HOL; the theory loader path already includes this directory
  8073 by default; the following existing theories have been moved here:
  8074 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  8075 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  8076 
  8077 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  8078 modelling and verification task performed in Isabelle/HOL +
  8079 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  8080 
  8081 * HOL/Algebra: special summation operator SUM no longer exists, it has
  8082 been replaced by setsum; infix 'assoc' now has priority 50 (like
  8083 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  8084 'domain', this makes the theory consistent with mathematical
  8085 literature;
  8086 
  8087 * HOL basics: added overloaded operations "inverse" and "divide"
  8088 (infix "/"), syntax for generic "abs" operation, generic summation
  8089 operator \<Sum>;
  8090 
  8091 * HOL/typedef: simplified package, provide more useful rules (see also
  8092 HOL/subset.thy);
  8093 
  8094 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  8095 now expressed as a proper nested rule (old-style tactic scripts may
  8096 require atomize_strip_tac to cope with non-atomic premises);
  8097 
  8098 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  8099 to "split_conv" (old name still available for compatibility);
  8100 
  8101 * HOL: improved concrete syntax for strings (e.g. allows translation
  8102 rules with string literals);
  8103 
  8104 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  8105  and Fleuriot's mechanization of analysis, including the transcendental
  8106  functions for the reals;
  8107 
  8108 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  8109 
  8110 
  8111 *** CTT ***
  8112 
  8113 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  8114 "lam" is displayed as TWO lambda-symbols
  8115 
  8116 * CTT: theory Main now available, containing everything (that is, Bool
  8117 and Arith);
  8118 
  8119 
  8120 *** General ***
  8121 
  8122 * Pure: the Simplifier has been implemented properly as a derived rule
  8123 outside of the actual kernel (at last!); the overall performance
  8124 penalty in practical applications is about 50%, while reliability of
  8125 the Isabelle inference kernel has been greatly improved;
  8126 
  8127 * print modes "brackets" and "no_brackets" control output of nested =>
  8128 (types) and ==> (props); the default behaviour is "brackets";
  8129 
  8130 * Provers: fast_tac (and friends) now handle actual object-logic rules
  8131 as assumptions as well;
  8132 
  8133 * system: support Poly/ML 4.0;
  8134 
  8135 * system: isatool install handles KDE version 1 or 2;
  8136 
  8137 
  8138 
  8139 New in Isabelle99-1 (October 2000)
  8140 ----------------------------------
  8141 
  8142 *** Overview of INCOMPATIBILITIES ***
  8143 
  8144 * HOL: simplification of natural numbers is much changed; to partly
  8145 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  8146 issue the following ML commands:
  8147 
  8148   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  8149   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  8150 
  8151 * HOL: simplification no longer dives into case-expressions; this is
  8152 controlled by "t.weak_case_cong" for each datatype t;
  8153 
  8154 * HOL: nat_less_induct renamed to less_induct;
  8155 
  8156 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  8157 fixsome to patch .thy and .ML sources automatically;
  8158 
  8159   select_equality  -> some_equality
  8160   select_eq_Ex     -> some_eq_ex
  8161   selectI2EX       -> someI2_ex
  8162   selectI2         -> someI2
  8163   selectI          -> someI
  8164   select1_equality -> some1_equality
  8165   Eps_sym_eq       -> some_sym_eq_trivial
  8166   Eps_eq           -> some_eq_trivial
  8167 
  8168 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  8169 
  8170 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  8171 instead);
  8172 
  8173 * HOL: the recursion equations generated by 'recdef' are now called
  8174 f.simps instead of f.rules;
  8175 
  8176 * HOL: qed_spec_mp now also handles bounded ALL as well;
  8177 
  8178 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  8179 sometimes be needed;
  8180 
  8181 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  8182 
  8183 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  8184 
  8185 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  8186 product is now "<*>" instead of "Times"; the lexicographic product is
  8187 now "<*lex*>" instead of "**";
  8188 
  8189 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  8190 of main HOL, but was unused); better use HOL's datatype package;
  8191 
  8192 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  8193 the old syntax may be recovered as follows:
  8194 
  8195   syntax (symbols)
  8196     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  8197       (infixl "\\<oplus>" 100)
  8198 
  8199 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  8200 
  8201 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  8202 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  8203 internally;
  8204 
  8205 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  8206 changed from A/r to A//r;
  8207 
  8208 * ZF: new treatment of arithmetic (nat & int) may break some old
  8209 proofs;
  8210 
  8211 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  8212 rulify -> rule_format, elimify -> elim_format, ...);
  8213 
  8214 * Isar/Provers: intro/elim/dest attributes changed; renamed
  8215 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  8216 should have to change intro!! to intro? only); replaced "delrule" by
  8217 "rule del";
  8218 
  8219 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  8220 
  8221 * Provers: strengthened force_tac by using new first_best_tac;
  8222 
  8223 * LaTeX document preparation: several changes of isabelle.sty (see
  8224 lib/texinputs);
  8225 
  8226 
  8227 *** Document preparation ***
  8228 
  8229 * formal comments (text blocks etc.) in new-style theories may now
  8230 contain antiquotations of thm/prop/term/typ/text to be presented
  8231 according to latex print mode; concrete syntax is like this:
  8232 @{term[show_types] "f(x) = a + x"};
  8233 
  8234 * isatool mkdir provides easy setup of Isabelle session directories,
  8235 including proper document sources;
  8236 
  8237 * generated LaTeX sources are now deleted after successful run
  8238 (isatool document -c); may retain a copy somewhere else via -D option
  8239 of isatool usedir;
  8240 
  8241 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  8242 style files, achieving self-contained LaTeX sources and simplifying
  8243 LaTeX debugging;
  8244 
  8245 * old-style theories now produce (crude) LaTeX output as well;
  8246 
  8247 * browser info session directories are now self-contained (may be put
  8248 on WWW server seperately); improved graphs of nested sessions; removed
  8249 graph for 'all sessions';
  8250 
  8251 * several improvements in isabelle style files; \isabellestyle{it}
  8252 produces fake math mode output; \isamarkupheader is now \section by
  8253 default; see lib/texinputs/isabelle.sty etc.;
  8254 
  8255 
  8256 *** Isar ***
  8257 
  8258 * Isar/Pure: local results and corresponding term bindings are now
  8259 subject to Hindley-Milner polymorphism (similar to ML); this
  8260 accommodates incremental type-inference very nicely;
  8261 
  8262 * Isar/Pure: new derived language element 'obtain' supports
  8263 generalized existence reasoning;
  8264 
  8265 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  8266 support accumulation of results, without applying any rules yet;
  8267 useful to collect intermediate results without explicit name
  8268 references, and for use with transitivity rules with more than 2
  8269 premises;
  8270 
  8271 * Isar/Pure: scalable support for case-analysis type proofs: new
  8272 'case' language element refers to local contexts symbolically, as
  8273 produced by certain proof methods; internally, case names are attached
  8274 to theorems as "tags";
  8275 
  8276 * Isar/Pure: theory command 'hide' removes declarations from
  8277 class/type/const name spaces;
  8278 
  8279 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  8280 indicate potential overloading;
  8281 
  8282 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  8283 
  8284 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  8285 "{a,b,c}" instead of {a,b,c};
  8286 
  8287 * Isar/Pure now provides its own version of intro/elim/dest
  8288 attributes; useful for building new logics, but beware of confusion
  8289 with the version in Provers/classical;
  8290 
  8291 * Isar/Pure: the local context of (non-atomic) goals is provided via
  8292 case name 'antecedent';
  8293 
  8294 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  8295 to the current context is now done automatically);
  8296 
  8297 * Isar/Pure: theory command 'method_setup' provides a simple interface
  8298 for definining proof methods in ML;
  8299 
  8300 * Isar/Provers: intro/elim/dest attributes changed; renamed
  8301 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  8302 most cases, one should have to change intro!! to intro? only);
  8303 replaced "delrule" by "rule del";
  8304 
  8305 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  8306 'symmetric' attribute (the latter supercedes [RS sym]);
  8307 
  8308 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  8309 method modifier); 'simp' method: 'only:' modifier removes loopers as
  8310 well (including splits);
  8311 
  8312 * Isar/Provers: Simplifier and Classical methods now support all kind
  8313 of modifiers used in the past, including 'cong', 'iff', etc.
  8314 
  8315 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  8316 of Simplifier and Classical reasoner);
  8317 
  8318 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  8319 now support named cases; major packages (inductive, datatype, primrec,
  8320 recdef) support case names and properly name parameters;
  8321 
  8322 * Isar/HOL: new transitivity rules for substitution in inequalities --
  8323 monotonicity conditions are extracted to be proven at end of
  8324 calculations;
  8325 
  8326 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  8327 method anyway;
  8328 
  8329 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  8330 split_if split_if_asm; datatype package provides theorems foo.splits =
  8331 foo.split foo.split_asm for each datatype;
  8332 
  8333 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  8334 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  8335 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  8336 use "(cases (simplified))" method in proper proof texts);
  8337 
  8338 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  8339 
  8340 * Isar: names of theorems etc. may be natural numbers as well;
  8341 
  8342 * Isar: 'pr' command: optional arguments for goals_limit and
  8343 ProofContext.prems_limit; no longer prints theory contexts, but only
  8344 proof states;
  8345 
  8346 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  8347 additional print modes to be specified; e.g. "pr(latex)" will print
  8348 proof state according to the Isabelle LaTeX style;
  8349 
  8350 * Isar: improved support for emulating tactic scripts, including proof
  8351 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  8352 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  8353 (for HOL datatypes);
  8354 
  8355 * Isar: simplified (more robust) goal selection of proof methods: 1st
  8356 goal, all goals, or explicit goal specifier (tactic emulation); thus
  8357 'proof method scripts' have to be in depth-first order;
  8358 
  8359 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  8360 
  8361 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  8362 should instead use individual commands for printing items
  8363 (print_commands, print_methods etc.);
  8364 
  8365 * Isar: added 'nothing' --- the empty list of theorems;
  8366 
  8367 
  8368 *** HOL ***
  8369 
  8370 * HOL/MicroJava: formalization of a fragment of Java, together with a
  8371 corresponding virtual machine and a specification of its bytecode
  8372 verifier and a lightweight bytecode verifier, including proofs of
  8373 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  8374 Cornelia Pusch (see also the homepage of project Bali at
  8375 http://isabelle.in.tum.de/Bali/);
  8376 
  8377 * HOL/Algebra: new theory of rings and univariate polynomials, by
  8378 Clemens Ballarin;
  8379 
  8380 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  8381 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  8382 Rasmussen;
  8383 
  8384 * HOL/Lattice: fundamental concepts of lattice theory and order
  8385 structures, including duals, properties of bounds versus algebraic
  8386 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  8387 Theorem for complete lattices etc.; may also serve as a demonstration
  8388 for abstract algebraic reasoning using axiomatic type classes, and
  8389 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  8390 
  8391 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  8392 von Oheimb;
  8393 
  8394 * HOL/IMPP: extension of IMP with local variables and mutually
  8395 recursive procedures, by David von Oheimb;
  8396 
  8397 * HOL/Lambda: converted into new-style theory and document;
  8398 
  8399 * HOL/ex/Multiquote: example of multiple nested quotations and
  8400 anti-quotations -- basically a generalized version of de-Bruijn
  8401 representation; very useful in avoiding lifting of operations;
  8402 
  8403 * HOL/record: added general record equality rule to simpset; fixed
  8404 select-update simplification procedure to handle extended records as
  8405 well; admit "r" as field name;
  8406 
  8407 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  8408 other numeric types and also as the identity of groups, rings, etc.;
  8409 
  8410 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  8411 Types nat and int belong to this axclass;
  8412 
  8413 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  8414    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  8415    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  8416   two terms #m*u and #n*u are replaced by #(m+n)*u
  8417     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  8418   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  8419     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  8420 
  8421 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  8422 powerful prover for predicate logic but knows nothing of clasets; see
  8423 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  8424 
  8425 * HOL: new version of "case_tac" subsumes both boolean case split and
  8426 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  8427 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  8428 
  8429 * HOL: simplification no longer dives into case-expressions: only the
  8430 selector expression is simplified, but not the remaining arms; to
  8431 enable full simplification of case-expressions for datatype t, you may
  8432 remove t.weak_case_cong from the simpset, either globally (Delcongs
  8433 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  8434 
  8435 * HOL/recdef: the recursion equations generated by 'recdef' for
  8436 function 'f' are now called f.simps instead of f.rules; if all
  8437 termination conditions are proved automatically, these simplification
  8438 rules are added to the simpset, as in primrec; rules may be named
  8439 individually as well, resulting in a separate list of theorems for
  8440 each equation;
  8441 
  8442 * HOL/While is a new theory that provides a while-combinator. It
  8443 permits the definition of tail-recursive functions without the
  8444 provision of a termination measure. The latter is necessary once the
  8445 invariant proof rule for while is applied.
  8446 
  8447 * HOL: new (overloaded) notation for the set of elements below/above
  8448 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  8449 
  8450 * HOL: theorems impI, allI, ballI bound as "strip";
  8451 
  8452 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  8453 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  8454 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  8455 
  8456 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  8457 
  8458 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  8459 main HOL, but was unused);
  8460 
  8461 * HOL: fewer consts declared as global (e.g. have to refer to
  8462 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  8463 
  8464 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  8465 in case of overlap with user translations (e.g. judgements over
  8466 tuples); (note that the underlying logical represenation is still
  8467 bogus);
  8468 
  8469 
  8470 *** ZF ***
  8471 
  8472 * ZF: simplification automatically cancels common terms in arithmetic
  8473 expressions over nat and int;
  8474 
  8475 * ZF: new treatment of nat to minimize type-checking: all operators
  8476 coerce their operands to a natural number using the function natify,
  8477 making the algebraic laws unconditional;
  8478 
  8479 * ZF: as above, for int: operators coerce their operands to an integer
  8480 using the function intify;
  8481 
  8482 * ZF: the integer library now contains many of the usual laws for the
  8483 orderings, including $<=, and monotonicity laws for $+ and $*;
  8484 
  8485 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  8486 simplification;
  8487 
  8488 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  8489 to the simplifier and classical reasoner simultaneously;
  8490 
  8491 
  8492 *** General ***
  8493 
  8494 * Provers: blast_tac now handles actual object-logic rules as
  8495 assumptions; note that auto_tac uses blast_tac internally as well;
  8496 
  8497 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  8498 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  8499 
  8500 * Provers: delrules now handles destruct rules as well (no longer need
  8501 explicit make_elim);
  8502 
  8503 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  8504   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  8505 use instead the strong form,
  8506   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  8507 in HOL, FOL and ZF the function cla_make_elim will create such rules
  8508 from destruct-rules;
  8509 
  8510 * Provers: Simplifier.easy_setup provides a fast path to basic
  8511 Simplifier setup for new object-logics;
  8512 
  8513 * Pure: AST translation rules no longer require constant head on LHS;
  8514 
  8515 * Pure: improved name spaces: ambiguous output is qualified; support
  8516 for hiding of names;
  8517 
  8518 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  8519 XSYMBOL_HOME; no longer need to do manual configuration in most
  8520 situations;
  8521 
  8522 * system: compression of ML heaps images may now be controlled via -c
  8523 option of isabelle and isatool usedir (currently only observed by
  8524 Poly/ML);
  8525 
  8526 * system: isatool installfonts may handle X-Symbol fonts as well (very
  8527 useful for remote X11);
  8528 
  8529 * system: provide TAGS file for Isabelle sources;
  8530 
  8531 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  8532 order;
  8533 
  8534 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  8535 timing flag supersedes proof_timing and Toplevel.trace;
  8536 
  8537 * ML: new combinators |>> and |>>> for incremental transformations
  8538 with secondary results (e.g. certain theory extensions):
  8539 
  8540 * ML: PureThy.add_defs gets additional argument to indicate potential
  8541 overloading (usually false);
  8542 
  8543 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  8544 results;
  8545 
  8546 
  8547 
  8548 New in Isabelle99 (October 1999)
  8549 --------------------------------
  8550 
  8551 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8552 
  8553 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  8554 are no longer simplified.  (This allows the simplifier to unfold recursive
  8555 functional programs.)  To restore the old behaviour, declare
  8556 
  8557     Delcongs [if_weak_cong];
  8558 
  8559 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  8560 complement;
  8561 
  8562 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  8563 
  8564 * HOL/datatype: mutual_induct_tac no longer exists --
  8565   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  8566 
  8567 * HOL/typedef: fixed type inference for representing set; type
  8568 arguments now have to occur explicitly on the rhs as type constraints;
  8569 
  8570 * ZF: The con_defs part of an inductive definition may no longer refer
  8571 to constants declared in the same theory;
  8572 
  8573 * HOL, ZF: the function mk_cases, generated by the inductive
  8574 definition package, has lost an argument.  To simplify its result, it
  8575 uses the default simpset instead of a supplied list of theorems.
  8576 
  8577 * HOL/List: the constructors of type list are now Nil and Cons;
  8578 
  8579 * Simplifier: the type of the infix ML functions
  8580         setSSolver addSSolver setSolver addSolver
  8581 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  8582 for packaging solvers. A solver is created via
  8583         mk_solver: string -> (thm list -> int -> tactic) -> solver
  8584 where the string argument is only a comment.
  8585 
  8586 
  8587 *** Proof tools ***
  8588 
  8589 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  8590 decision procedure for linear arithmetic. Currently it is used for
  8591 types `nat', `int', and `real' in HOL (see below); it can, should and
  8592 will be instantiated for other types and logics as well.
  8593 
  8594 * The simplifier now accepts rewrite rules with flexible heads, eg
  8595      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  8596   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  8597   matching.
  8598 
  8599 
  8600 *** General ***
  8601 
  8602 * New Isabelle/Isar subsystem provides an alternative to traditional
  8603 tactical theorem proving; together with the ProofGeneral/isar user
  8604 interface it offers an interactive environment for developing human
  8605 readable proof documents (Isar == Intelligible semi-automated
  8606 reasoning); for further information see isatool doc isar-ref,
  8607 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  8608 
  8609 * improved and simplified presentation of theories: better HTML markup
  8610 (including colors), graph views in several sizes; isatool usedir now
  8611 provides a proper interface for user theories (via -P option); actual
  8612 document preparation based on (PDF)LaTeX is available as well (for
  8613 new-style theories only); see isatool doc system for more information;
  8614 
  8615 * native support for Proof General, both for classic Isabelle and
  8616 Isabelle/Isar;
  8617 
  8618 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  8619 using the graph browser tool;
  8620 
  8621 * Isabelle manuals now also available as PDF;
  8622 
  8623 * theory loader rewritten from scratch (may not be fully
  8624 bug-compatible); old loadpath variable has been replaced by show_path,
  8625 add_path, del_path, reset_path functions; new operations such as
  8626 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  8627 isatool doc ref);
  8628 
  8629 * improved isatool install: option -k creates KDE application icon,
  8630 option -p DIR installs standalone binaries;
  8631 
  8632 * added ML_PLATFORM setting (useful for cross-platform installations);
  8633 more robust handling of platform specific ML images for SML/NJ;
  8634 
  8635 * the settings environment is now statically scoped, i.e. it is never
  8636 created again in sub-processes invoked from isabelle, isatool, or
  8637 Isabelle;
  8638 
  8639 * path element specification '~~' refers to '$ISABELLE_HOME';
  8640 
  8641 * in locales, the "assumes" and "defines" parts may be omitted if
  8642 empty;
  8643 
  8644 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  8645 long arrows);
  8646 
  8647 * new print_mode "HTML";
  8648 
  8649 * new flag show_tags controls display of tags of theorems (which are
  8650 basically just comments that may be attached by some tools);
  8651 
  8652 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  8653 mode and goal output format:
  8654 
  8655 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  8656 244c244
  8657 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  8658 ---
  8659 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  8660 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  8661 181c181
  8662 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  8663 ---
  8664 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  8665 
  8666 * function bind_thms stores lists of theorems (cf. bind_thm);
  8667 
  8668 * new shorthand tactics ftac, eatac, datac, fatac;
  8669 
  8670 * qed (and friends) now accept "" as result name; in that case the
  8671 theorem is not stored, but proper checks and presentation of the
  8672 result still apply;
  8673 
  8674 * theorem database now also indexes constants "Trueprop", "all",
  8675 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  8676 
  8677 
  8678 *** HOL ***
  8679 
  8680 ** HOL arithmetic **
  8681 
  8682 * There are now decision procedures for linear arithmetic over nat and
  8683 int:
  8684 
  8685 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  8686 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  8687 are treated as atomic; subformulae not involving type `nat' or `int'
  8688 are ignored; quantified subformulae are ignored unless they are
  8689 positive universal or negative existential. The tactic has to be
  8690 invoked by hand and can be a little bit slow. In particular, the
  8691 running time is exponential in the number of occurrences of `min' and
  8692 `max', and `-' on `nat'.
  8693 
  8694 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  8695 (negated) (in)equalities among the premises and the conclusion into
  8696 account (i.e. no compound formulae) and does not know about `min' and
  8697 `max', and `-' on `nat'. It is fast and is used automatically by the
  8698 simplifier.
  8699 
  8700 NB: At the moment, these decision procedures do not cope with mixed
  8701 nat/int formulae where the two parts interact, such as `m < n ==>
  8702 int(m) < int(n)'.
  8703 
  8704 * HOL/Numeral provides a generic theory of numerals (encoded
  8705 efficiently as bit strings); setup for types nat/int/real is in place;
  8706 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  8707 int, existing theories and proof scripts may require a few additional
  8708 type constraints;
  8709 
  8710 * integer division and remainder can now be performed on constant
  8711 arguments;
  8712 
  8713 * many properties of integer multiplication, division and remainder
  8714 are now available;
  8715 
  8716 * An interface to the Stanford Validity Checker (SVC) is available through the
  8717 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  8718 are proved automatically.  SVC must be installed separately, and its results
  8719 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  8720 invocation of the underlying oracle).  For SVC see
  8721   http://verify.stanford.edu/SVC
  8722 
  8723 * IsaMakefile: the HOL-Real target now builds an actual image;
  8724 
  8725 
  8726 ** HOL misc **
  8727 
  8728 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  8729 (in Isabelle/Isar) -- by Gertrud Bauer;
  8730 
  8731 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  8732 analysis for assembly languages with subtypes;
  8733 
  8734 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  8735 -- avoids syntactic ambiguities and treats state, transition, and
  8736 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  8737 changed syntax and (many) tactics;
  8738 
  8739 * HOL/inductive: Now also handles more general introduction rules such
  8740   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  8741   theorems are now maintained within the theory (maintained via the
  8742   "mono" attribute);
  8743 
  8744 * HOL/datatype: Now also handles arbitrarily branching datatypes
  8745   (using function types) such as
  8746 
  8747   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  8748 
  8749 * HOL/record: record_simproc (part of the default simpset) takes care
  8750 of selectors applied to updated records; record_split_tac is no longer
  8751 part of the default claset; update_defs may now be removed from the
  8752 simpset in many cases; COMPATIBILITY: old behavior achieved by
  8753 
  8754   claset_ref () := claset() addSWrapper record_split_wrapper;
  8755   Delsimprocs [record_simproc]
  8756 
  8757 * HOL/typedef: fixed type inference for representing set; type
  8758 arguments now have to occur explicitly on the rhs as type constraints;
  8759 
  8760 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  8761 names rather than an ML expression;
  8762 
  8763 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  8764 supplied later.  Program schemes can be defined, such as
  8765     "While B C s = (if B s then While B C (C s) else s)"
  8766 where the well-founded relation can be chosen after B and C have been given.
  8767 
  8768 * HOL/List: the constructors of type list are now Nil and Cons;
  8769 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  8770 course, ML tools referring to List.list.op # etc. have to be adapted;
  8771 
  8772 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  8773 disabled by default; run isabelle with option -m HOL to get back to
  8774 the original Gordon/HOL-style output;
  8775 
  8776 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  8777 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  8778 
  8779 * HOL basic syntax simplified (more orthogonal): all variants of
  8780 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  8781 Eps operator is provided as well: "SOME x. P[x]";
  8782 
  8783 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  8784 
  8785 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  8786 thus available for user theories;
  8787 
  8788 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  8789 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  8790 time;
  8791 
  8792 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  8793 several times and then mp;
  8794 
  8795 
  8796 *** LK ***
  8797 
  8798 * the notation <<...>> is now available as a notation for sequences of
  8799 formulas;
  8800 
  8801 * the simplifier is now installed
  8802 
  8803 * the axiom system has been generalized (thanks to Soren Heilmann)
  8804 
  8805 * the classical reasoner now has a default rule database
  8806 
  8807 
  8808 *** ZF ***
  8809 
  8810 * new primrec section allows primitive recursive functions to be given
  8811 directly (as in HOL) over datatypes and the natural numbers;
  8812 
  8813 * new tactics induct_tac and exhaust_tac for induction (or case
  8814 analysis) over datatypes and the natural numbers;
  8815 
  8816 * the datatype declaration of type T now defines the recursor T_rec;
  8817 
  8818 * simplification automatically does freeness reasoning for datatype
  8819 constructors;
  8820 
  8821 * automatic type-inference, with AddTCs command to insert new
  8822 type-checking rules;
  8823 
  8824 * datatype introduction rules are now added as Safe Introduction rules
  8825 to the claset;
  8826 
  8827 * the syntax "if P then x else y" is now available in addition to
  8828 if(P,x,y);
  8829 
  8830 
  8831 *** Internal programming interfaces ***
  8832 
  8833 * tuned simplifier trace output; new flag debug_simp;
  8834 
  8835 * structures Vartab / Termtab (instances of TableFun) offer efficient
  8836 tables indexed by indexname_ord / term_ord (compatible with aconv);
  8837 
  8838 * AxClass.axclass_tac lost the theory argument;
  8839 
  8840 * tuned current_goals_markers semantics: begin / end goal avoids
  8841 printing empty lines;
  8842 
  8843 * removed prs and prs_fn hook, which was broken because it did not
  8844 include \n in its semantics, forcing writeln to add one
  8845 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  8846 string -> unit if you really want to output text without newline;
  8847 
  8848 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  8849 plain output, interface builders may have to enable 'isabelle_font'
  8850 mode to get Isabelle font glyphs as before;
  8851 
  8852 * refined token_translation interface; INCOMPATIBILITY: output length
  8853 now of type real instead of int;
  8854 
  8855 * theory loader actions may be traced via new ThyInfo.add_hook
  8856 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8857 your own database of information attached to *whole* theories -- as
  8858 opposed to intra-theory data slots offered via TheoryDataFun;
  8859 
  8860 * proper handling of dangling sort hypotheses (at last!);
  8861 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8862 extra sort hypotheses that can be witnessed from the type signature;
  8863 the force_strip_shyps flag is gone, any remaining shyps are simply
  8864 left in the theorem (with a warning issued by strip_shyps_warning);
  8865 
  8866 
  8867 
  8868 New in Isabelle98-1 (October 1998)
  8869 ----------------------------------
  8870 
  8871 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8872 
  8873 * several changes of automated proof tools;
  8874 
  8875 * HOL: major changes to the inductive and datatype packages, including
  8876 some minor incompatibilities of theory syntax;
  8877 
  8878 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8879 called `inj_on';
  8880 
  8881 * HOL: removed duplicate thms in Arith:
  8882   less_imp_add_less  should be replaced by  trans_less_add1
  8883   le_imp_add_le      should be replaced by  trans_le_add1
  8884 
  8885 * HOL: unary minus is now overloaded (new type constraints may be
  8886 required);
  8887 
  8888 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8889 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8890 now taken as an integer constant.
  8891 
  8892 * Pure: ML function 'theory_of' renamed to 'theory';
  8893 
  8894 
  8895 *** Proof tools ***
  8896 
  8897 * Simplifier:
  8898   1. Asm_full_simp_tac is now more aggressive.
  8899      1. It will sometimes reorient premises if that increases their power to
  8900         simplify.
  8901      2. It does no longer proceed strictly from left to right but may also
  8902         rotate premises to achieve further simplification.
  8903      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8904      old Asm_full_simp_tac in that it does not rotate premises.
  8905   2. The simplifier now knows a little bit about nat-arithmetic.
  8906 
  8907 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8908 allows for selected deletion of wrappers, by introduction of names for
  8909 wrapper functionals.  This implies that addbefore, addSbefore,
  8910 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8911 and that adding two tactics with the same name overwrites the first
  8912 one (emitting a warning).
  8913   type wrapper = (int -> tactic) -> (int -> tactic)
  8914   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8915   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8916   delWrapper, delSWrapper: claset *  string            -> claset
  8917   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8918 
  8919 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8920 semantics; addbefore now affects only the unsafe part of step_tac
  8921 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8922 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8923 by Force_tac;
  8924 
  8925 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8926 compWrapper; added safe wrapper (and access functions for it);
  8927 
  8928 * HOL/split_all_tac is now much faster and fails if there is nothing
  8929 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8930 and the names of the automatically generated variables have changed.
  8931 split_all_tac has moved within claset() from unsafe wrappers to safe
  8932 wrappers, which means that !!-bound variables are split much more
  8933 aggressively, and safe_tac and clarify_tac now split such variables.
  8934 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8935 Note: the same holds for record_split_tac, which does the job of
  8936 split_all_tac for record fields.
  8937 
  8938 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8939 permanently to the default simpset using Addsplits just like
  8940 Addsimps. They can be removed via Delsplits just like
  8941 Delsimps. Lower-case versions are also available.
  8942 
  8943 * HOL/Simplifier: The rule split_if is now part of the default
  8944 simpset. This means that the simplifier will eliminate all occurrences
  8945 of if-then-else in the conclusion of a goal. To prevent this, you can
  8946 either remove split_if completely from the default simpset by
  8947 `Delsplits [split_if]' or remove it in a specific call of the
  8948 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8949 other case splitting rules to/from the default simpset: every datatype
  8950 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8951 t is the name of the datatype).
  8952 
  8953 * Classical reasoner / Simplifier combination: new force_tac (and
  8954 derivatives Force_tac, force) combines rewriting and classical
  8955 reasoning (and whatever other tools) similarly to auto_tac, but is
  8956 aimed to solve the given subgoal completely.
  8957 
  8958 
  8959 *** General ***
  8960 
  8961 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8962 and `goalw': the theory is no longer needed as an explicit argument -
  8963 the current theory context is used; assumptions are no longer returned
  8964 at the ML-level unless one of them starts with ==> or !!; it is
  8965 recommended to convert to these new commands using isatool fixgoal
  8966 (backup your sources first!);
  8967 
  8968 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8969 the current theory context, and 'theory' to lookup stored theories;
  8970 
  8971 * new theory section 'locale' for declaring constants, assumptions and
  8972 definitions that have local scope;
  8973 
  8974 * new theory section 'nonterminals' for purely syntactic types;
  8975 
  8976 * new theory section 'setup' for generic ML setup functions
  8977 (e.g. package initialization);
  8978 
  8979 * the distribution now includes Isabelle icons: see
  8980 lib/logo/isabelle-{small,tiny}.xpm;
  8981 
  8982 * isatool install - install binaries with absolute references to
  8983 ISABELLE_HOME/bin;
  8984 
  8985 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8986 
  8987 * print mode 'emacs' reserved for Isamode;
  8988 
  8989 * support multiple print (ast) translations per constant name;
  8990 
  8991 * theorems involving oracles are now printed with a suffixed [!];
  8992 
  8993 
  8994 *** HOL ***
  8995 
  8996 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8997 
  8998 * HOL/inductive package reorganized and improved: now supports mutual
  8999 definitions such as
  9000 
  9001   inductive EVEN ODD
  9002     intrs
  9003       null "0 : EVEN"
  9004       oddI "n : EVEN ==> Suc n : ODD"
  9005       evenI "n : ODD ==> Suc n : EVEN"
  9006 
  9007 new theorem list "elims" contains an elimination rule for each of the
  9008 recursive sets; inductive definitions now handle disjunctive premises
  9009 correctly (also ZF);
  9010 
  9011 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  9012 "mutual_induct" no longer exists - the induction rule is always
  9013 contained in "induct";
  9014 
  9015 
  9016 * HOL/datatype package re-implemented and greatly improved: now
  9017 supports mutually recursive datatypes such as
  9018 
  9019   datatype
  9020     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  9021             | SUM ('a aexp) ('a aexp)
  9022             | DIFF ('a aexp) ('a aexp)
  9023             | NUM 'a
  9024   and
  9025     'a bexp = LESS ('a aexp) ('a aexp)
  9026             | AND ('a bexp) ('a bexp)
  9027             | OR ('a bexp) ('a bexp)
  9028 
  9029 as well as indirectly recursive datatypes such as
  9030 
  9031   datatype
  9032     ('a, 'b) term = Var 'a
  9033                   | App 'b ((('a, 'b) term) list)
  9034 
  9035 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  9036 induction on mutually / indirectly recursive datatypes.
  9037 
  9038 Primrec equations are now stored in theory and can be accessed via
  9039 <function_name>.simps.
  9040 
  9041 INCOMPATIBILITIES:
  9042 
  9043   - Theories using datatypes must now have theory Datatype as an
  9044     ancestor.
  9045   - The specific <typename>.induct_tac no longer exists - use the
  9046     generic induct_tac instead.
  9047   - natE has been renamed to nat.exhaust - use exhaust_tac
  9048     instead of res_inst_tac ... natE. Note that the variable
  9049     names in nat.exhaust differ from the names in natE, this
  9050     may cause some "fragile" proofs to fail.
  9051   - The theorems split_<typename>_case and split_<typename>_case_asm
  9052     have been renamed to <typename>.split and <typename>.split_asm.
  9053   - Since default sorts of type variables are now handled correctly,
  9054     some datatype definitions may have to be annotated with explicit
  9055     sort constraints.
  9056   - Primrec definitions no longer require function name and type
  9057     of recursive argument.
  9058 
  9059 Consider using isatool fixdatatype to adapt your theories and proof
  9060 scripts to the new package (backup your sources first!).
  9061 
  9062 
  9063 * HOL/record package: considerably improved implementation; now
  9064 includes concrete syntax for record types, terms, updates; theorems
  9065 for surjective pairing and splitting !!-bound record variables; proof
  9066 support is as follows:
  9067 
  9068   1) standard conversions (selectors or updates applied to record
  9069 constructor terms) are part of the standard simpset;
  9070 
  9071   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  9072 made part of standard simpset and claset via addIffs;
  9073 
  9074   3) a tactic for record field splitting (record_split_tac) is part of
  9075 the standard claset (addSWrapper);
  9076 
  9077 To get a better idea about these rules you may retrieve them via
  9078 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  9079 the name of your record type.
  9080 
  9081 The split tactic 3) conceptually simplifies by the following rule:
  9082 
  9083   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  9084 
  9085 Thus any record variable that is bound by meta-all will automatically
  9086 blow up into some record constructor term, consequently the
  9087 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  9088 solve record problems automatically.
  9089 
  9090 
  9091 * reorganized the main HOL image: HOL/Integ and String loaded by
  9092 default; theory Main includes everything;
  9093 
  9094 * automatic simplification of integer sums and comparisons, using cancellation;
  9095 
  9096 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  9097 
  9098 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  9099 
  9100 * many new identities for unions, intersections, set difference, etc.;
  9101 
  9102 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  9103 called split_if, split_split, split_sum_case and split_nat_case (to go
  9104 with add/delsplits);
  9105 
  9106 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  9107 (?x::unit) = (); this is made part of the default simpset, which COULD
  9108 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  9109 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  9110 unit_abs_eta_conv is added in order to counter the effect of
  9111 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  9112 %u.f();
  9113 
  9114 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  9115 makes more sense);
  9116 
  9117 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  9118   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  9119   disjointness reasoning but breaking a few old proofs.
  9120 
  9121 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  9122 to 'converse' from 'inverse' (for compatibility with ZF and some
  9123 literature);
  9124 
  9125 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  9126 the well-founded relation;
  9127 
  9128 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  9129     Compl A.  The "Compl" syntax remains available as input syntax for this
  9130     release ONLY.
  9131 
  9132 * HOL/Update: new theory of function updates:
  9133     f(a:=b) == %x. if x=a then b else f x
  9134 may also be iterated as in f(a:=b,c:=d,...);
  9135 
  9136 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  9137 
  9138 * HOL/List:
  9139   - new function list_update written xs[i:=v] that updates the i-th
  9140     list position. May also be iterated as in xs[i:=a,j:=b,...].
  9141   - new function `upt' written [i..j(] which generates the list
  9142     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  9143     bound write [i..j], which is a shorthand for [i..j+1(].
  9144   - new lexicographic orderings and corresponding wellfoundedness theorems.
  9145 
  9146 * HOL/Arith:
  9147   - removed 'pred' (predecessor) function;
  9148   - generalized some theorems about n-1;
  9149   - many new laws about "div" and "mod";
  9150   - new laws about greatest common divisors (see theory ex/Primes);
  9151 
  9152 * HOL/Relation: renamed the relational operator r^-1 "converse"
  9153 instead of "inverse";
  9154 
  9155 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  9156   of the multiset ordering;
  9157 
  9158 * directory HOL/Real: a construction of the reals using Dedekind cuts
  9159   (not included by default);
  9160 
  9161 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  9162 
  9163 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  9164   programs, i.e. different program variables may have different types.
  9165 
  9166 * calling (stac rew i) now fails if "rew" has no effect on the goal
  9167   [previously, this check worked only if the rewrite rule was unconditional]
  9168   Now rew can involve either definitions or equalities (either == or =).
  9169 
  9170 
  9171 *** ZF ***
  9172 
  9173 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  9174   only the theorems proved on ZF.ML;
  9175 
  9176 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  9177   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  9178   disjointness reasoning but breaking a few old proofs.
  9179 
  9180 * ZF/Update: new theory of function updates
  9181     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  9182   may also be iterated as in f(a:=b,c:=d,...);
  9183 
  9184 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  9185 
  9186 * calling (stac rew i) now fails if "rew" has no effect on the goal
  9187   [previously, this check worked only if the rewrite rule was unconditional]
  9188   Now rew can involve either definitions or equalities (either == or =).
  9189 
  9190 * case_tac provided for compatibility with HOL
  9191     (like the old excluded_middle_tac, but with subgoals swapped)
  9192 
  9193 
  9194 *** Internal programming interfaces ***
  9195 
  9196 * Pure: several new basic modules made available for general use, see
  9197 also src/Pure/README;
  9198 
  9199 * improved the theory data mechanism to support encapsulation (data
  9200 kind name replaced by private Object.kind, acting as authorization
  9201 key); new type-safe user interface via functor TheoryDataFun; generic
  9202 print_data function becomes basically useless;
  9203 
  9204 * removed global_names compatibility flag -- all theory declarations
  9205 are qualified by default;
  9206 
  9207 * module Pure/Syntax now offers quote / antiquote translation
  9208 functions (useful for Hoare logic etc. with implicit dependencies);
  9209 see HOL/ex/Antiquote for an example use;
  9210 
  9211 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  9212 cterm -> thm;
  9213 
  9214 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  9215 subgoal;
  9216 
  9217 * Display.print_goals function moved to Locale.print_goals;
  9218 
  9219 * standard print function for goals supports current_goals_markers
  9220 variable for marking begin of proof, end of proof, start of goal; the
  9221 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  9222 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  9223 for example;
  9224 
  9225 
  9226 
  9227 New in Isabelle98 (January 1998)
  9228 --------------------------------
  9229 
  9230 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  9231 
  9232 * changed lexical syntax of terms / types: dots made part of long
  9233 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  9234 
  9235 * simpset (and claset) reference variable replaced by functions
  9236 simpset / simpset_ref;
  9237 
  9238 * no longer supports theory aliases (via merge) and non-trivial
  9239 implicit merge of thms' signatures;
  9240 
  9241 * most internal names of constants changed due to qualified names;
  9242 
  9243 * changed Pure/Sequence interface (see Pure/seq.ML);
  9244 
  9245 
  9246 *** General Changes ***
  9247 
  9248 * hierachically structured name spaces (for consts, types, axms, thms
  9249 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  9250 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  9251 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  9252 long_names for fully qualified output names; NOTE: ML programs
  9253 (special tactics, packages etc.) referring to internal names may have
  9254 to be adapted to cope with fully qualified names; in case of severe
  9255 backward campatibility problems try setting 'global_names' at compile
  9256 time to have enrything declared within a flat name space; one may also
  9257 fine tune name declarations in theories via the 'global' and 'local'
  9258 section;
  9259 
  9260 * reimplemented the implicit simpset and claset using the new anytype
  9261 data filed in signatures; references simpset:simpset ref etc. are
  9262 replaced by functions simpset:unit->simpset and
  9263 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  9264 to patch your ML files accordingly;
  9265 
  9266 * HTML output now includes theory graph data for display with Java
  9267 applet or isatool browser; data generated automatically via isatool
  9268 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  9269 
  9270 * defs may now be conditional; improved rewrite_goals_tac to handle
  9271 conditional equations;
  9272 
  9273 * defs now admits additional type arguments, using TYPE('a) syntax;
  9274 
  9275 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  9276 creates a new theory node; implicit merge of thms' signatures is
  9277 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  9278 transfer:theory->thm->thm in (rare) cases;
  9279 
  9280 * improved handling of draft signatures / theories; draft thms (and
  9281 ctyps, cterms) are automatically promoted to real ones;
  9282 
  9283 * slightly changed interfaces for oracles: admit many per theory, named
  9284 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  9285 
  9286 * print_goals: optional output of const types (set show_consts and
  9287 show_types);
  9288 
  9289 * improved output of warnings (###) and errors (***);
  9290 
  9291 * subgoal_tac displays a warning if the new subgoal has type variables;
  9292 
  9293 * removed old README and Makefiles;
  9294 
  9295 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  9296 
  9297 * removed obsolete init_pps and init_database;
  9298 
  9299 * deleted the obsolete tactical STATE, which was declared by
  9300     fun STATE tacfun st = tacfun st st;
  9301 
  9302 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  9303 (which abbreviates $HOME);
  9304 
  9305 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  9306 use isatool fixseq to adapt your ML programs (this works for fully
  9307 qualified references to the Sequence structure only!);
  9308 
  9309 * use_thy no longer requires writable current directory; it always
  9310 reloads .ML *and* .thy file, if either one is out of date;
  9311 
  9312 
  9313 *** Classical Reasoner ***
  9314 
  9315 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  9316 tactics that use classical reasoning to simplify a subgoal without
  9317 splitting it into several subgoals;
  9318 
  9319 * Safe_tac: like safe_tac but uses the default claset;
  9320 
  9321 
  9322 *** Simplifier ***
  9323 
  9324 * added simplification meta rules:
  9325     (asm_)(full_)simplify: simpset -> thm -> thm;
  9326 
  9327 * simplifier.ML no longer part of Pure -- has to be loaded by object
  9328 logics (again);
  9329 
  9330 * added prems argument to simplification procedures;
  9331 
  9332 * HOL, FOL, ZF: added infix function `addsplits':
  9333   instead of `<simpset> setloop (split_tac <thms>)'
  9334   you can simply write `<simpset> addsplits <thms>'
  9335 
  9336 
  9337 *** Syntax ***
  9338 
  9339 * TYPE('a) syntax for type reflection terms;
  9340 
  9341 * no longer handles consts with name "" -- declare as 'syntax' instead;
  9342 
  9343 * pretty printer: changed order of mixfix annotation preference (again!);
  9344 
  9345 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  9346 
  9347 
  9348 *** HOL ***
  9349 
  9350 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  9351   with `addloop' of the simplifier to faciliate case splitting in premises.
  9352 
  9353 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  9354 
  9355 * HOL/Auth: new protocol proofs including some for the Internet
  9356   protocol TLS;
  9357 
  9358 * HOL/Map: new theory of `maps' a la VDM;
  9359 
  9360 * HOL/simplifier: simplification procedures nat_cancel_sums for
  9361 cancelling out common nat summands from =, <, <= (in)equalities, or
  9362 differences; simplification procedures nat_cancel_factor for
  9363 cancelling common factor from =, <, <= (in)equalities over natural
  9364 sums; nat_cancel contains both kinds of procedures, it is installed by
  9365 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  9366 
  9367 * HOL/simplifier: terms of the form
  9368   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  9369   are rewritten to
  9370   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  9371   and those of the form
  9372   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  9373   are rewritten to
  9374   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  9375 
  9376 * HOL/datatype
  9377   Each datatype `t' now comes with a theorem `split_t_case' of the form
  9378 
  9379   P(t_case f1 ... fn x) =
  9380      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  9381         ...
  9382        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  9383      )
  9384 
  9385   and a theorem `split_t_case_asm' of the form
  9386 
  9387   P(t_case f1 ... fn x) =
  9388     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  9389         ...
  9390        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  9391      )
  9392   which can be added to a simpset via `addsplits'. The existing theorems
  9393   expand_list_case and expand_option_case have been renamed to
  9394   split_list_case and split_option_case.
  9395 
  9396 * HOL/Arithmetic:
  9397   - `pred n' is automatically converted to `n-1'.
  9398     Users are strongly encouraged not to use `pred' any longer,
  9399     because it will disappear altogether at some point.
  9400   - Users are strongly encouraged to write "0 < n" rather than
  9401     "n ~= 0". Theorems and proof tools have been modified towards this
  9402     `standard'.
  9403 
  9404 * HOL/Lists:
  9405   the function "set_of_list" has been renamed "set" (and its theorems too);
  9406   the function "nth" now takes its arguments in the reverse order and
  9407   has acquired the infix notation "!" as in "xs!n".
  9408 
  9409 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  9410 
  9411 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  9412   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  9413 
  9414 * HOL/record: extensible records with schematic structural subtyping
  9415 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  9416 still lacks various theorems and concrete record syntax;
  9417 
  9418 
  9419 *** HOLCF ***
  9420 
  9421 * removed "axioms" and "generated by" sections;
  9422 
  9423 * replaced "ops" section by extended "consts" section, which is capable of
  9424   handling the continuous function space "->" directly;
  9425 
  9426 * domain package:
  9427   . proves theorems immediately and stores them in the theory,
  9428   . creates hierachical name space,
  9429   . now uses normal mixfix annotations (instead of cinfix...),
  9430   . minor changes to some names and values (for consistency),
  9431   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  9432   . separator between mutual domain defs: changed "," to "and",
  9433   . improved handling of sort constraints;  now they have to
  9434     appear on the left-hand side of the equations only;
  9435 
  9436 * fixed LAM <x,y,zs>.b syntax;
  9437 
  9438 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  9439 adm (%x. P (t x)), where P is chainfinite and t continuous;
  9440 
  9441 
  9442 *** FOL and ZF ***
  9443 
  9444 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  9445   with `addloop' of the simplifier to faciliate case splitting in premises.
  9446 
  9447 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  9448 in HOL, they strip ALL and --> from proved theorems;
  9449 
  9450 
  9451 
  9452 New in Isabelle94-8 (May 1997)
  9453 ------------------------------
  9454 
  9455 *** General Changes ***
  9456 
  9457 * new utilities to build / run / maintain Isabelle etc. (in parts
  9458 still somewhat experimental); old Makefiles etc. still functional;
  9459 
  9460 * new 'Isabelle System Manual';
  9461 
  9462 * INSTALL text, together with ./configure and ./build scripts;
  9463 
  9464 * reimplemented type inference for greater efficiency, better error
  9465 messages and clean internal interface;
  9466 
  9467 * prlim command for dealing with lots of subgoals (an easier way of
  9468 setting goals_limit);
  9469 
  9470 
  9471 *** Syntax ***
  9472 
  9473 * supports alternative (named) syntax tables (parser and pretty
  9474 printer); internal interface is provided by add_modesyntax(_i);
  9475 
  9476 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  9477 be used in conjunction with the Isabelle symbol font; uses the
  9478 "symbols" syntax table;
  9479 
  9480 * added token_translation interface (may translate name tokens in
  9481 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  9482 the current print_mode); IMPORTANT: user print translation functions
  9483 are responsible for marking newly introduced bounds
  9484 (Syntax.mark_boundT);
  9485 
  9486 * token translations for modes "xterm" and "xterm_color" that display
  9487 names in bold, underline etc. or colors (which requires a color
  9488 version of xterm);
  9489 
  9490 * infixes may now be declared with names independent of their syntax;
  9491 
  9492 * added typed_print_translation (like print_translation, but may
  9493 access type of constant);
  9494 
  9495 
  9496 *** Classical Reasoner ***
  9497 
  9498 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  9499 some limitations.  Blast_tac...
  9500   + ignores addss, addbefore, addafter; this restriction is intrinsic
  9501   + ignores elimination rules that don't have the correct format
  9502         (the conclusion MUST be a formula variable)
  9503   + ignores types, which can make HOL proofs fail
  9504   + rules must not require higher-order unification, e.g. apply_type in ZF
  9505     [message "Function Var's argument not a bound variable" relates to this]
  9506   + its proof strategy is more general but can actually be slower
  9507 
  9508 * substitution with equality assumptions no longer permutes other
  9509 assumptions;
  9510 
  9511 * minor changes in semantics of addafter (now called addaltern); renamed
  9512 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  9513 (and access functions for it);
  9514 
  9515 * improved combination of classical reasoner and simplifier:
  9516   + functions for handling clasimpsets
  9517   + improvement of addss: now the simplifier is called _after_ the
  9518     safe steps.
  9519   + safe variant of addss called addSss: uses safe simplifications
  9520     _during_ the safe steps. It is more complete as it allows multiple
  9521     instantiations of unknowns (e.g. with slow_tac).
  9522 
  9523 *** Simplifier ***
  9524 
  9525 * added interface for simplification procedures (functions that
  9526 produce *proven* rewrite rules on the fly, depending on current
  9527 redex);
  9528 
  9529 * ordering on terms as parameter (used for ordered rewriting);
  9530 
  9531 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  9532 
  9533 * the solver is now split into a safe and an unsafe part.
  9534 This should be invisible for the normal user, except that the
  9535 functions setsolver and addsolver have been renamed to setSolver and
  9536 addSolver; added safe_asm_full_simp_tac;
  9537 
  9538 
  9539 *** HOL ***
  9540 
  9541 * a generic induction tactic `induct_tac' which works for all datatypes and
  9542 also for type `nat';
  9543 
  9544 * a generic case distinction tactic `exhaust_tac' which works for all
  9545 datatypes and also for type `nat';
  9546 
  9547 * each datatype comes with a function `size';
  9548 
  9549 * patterns in case expressions allow tuple patterns as arguments to
  9550 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  9551 
  9552 * primrec now also works with type nat;
  9553 
  9554 * recdef: a new declaration form, allows general recursive functions to be
  9555 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  9556 
  9557 * the constant for negation has been renamed from "not" to "Not" to
  9558 harmonize with FOL, ZF, LK, etc.;
  9559 
  9560 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  9561 infinite lists;
  9562 
  9563 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  9564 
  9565 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  9566 problems in commutative rings, using axiomatic type classes for + and *;
  9567 
  9568 * more examples in HOL/MiniML and HOL/Auth;
  9569 
  9570 * more default rewrite rules for quantifiers, union/intersection;
  9571 
  9572 * a new constant `arbitrary == @x.False';
  9573 
  9574 * HOLCF/IOA replaces old HOL/IOA;
  9575 
  9576 * HOLCF changes: derived all rules and arities
  9577   + axiomatic type classes instead of classes
  9578   + typedef instead of faking type definitions
  9579   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  9580   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  9581   + eliminated the types void, one, tr
  9582   + use unit lift and bool lift (with translations) instead of one and tr
  9583   + eliminated blift from Lift3.thy (use Def instead of blift)
  9584   all eliminated rules are derived as theorems --> no visible changes ;
  9585 
  9586 
  9587 *** ZF ***
  9588 
  9589 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  9590 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  9591 as ZF_cs addSIs [equalityI];
  9592 
  9593 
  9594 
  9595 New in Isabelle94-7 (November 96)
  9596 ---------------------------------
  9597 
  9598 * allowing negative levels (as offsets) in prlev and choplev;
  9599 
  9600 * super-linear speedup for large simplifications;
  9601 
  9602 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  9603 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  9604 FAIL); can suppress it using the command Delsimps (ex_simps @
  9605 all_simps); De Morgan laws are also now included, by default;
  9606 
  9607 * improved printing of ==>  :  ~:
  9608 
  9609 * new object-logic "Sequents" adds linear logic, while replacing LK
  9610 and Modal (thanks to Sara Kalvala);
  9611 
  9612 * HOL/Auth: correctness proofs for authentication protocols;
  9613 
  9614 * HOL: new auto_tac combines rewriting and classical reasoning (many
  9615 examples on HOL/Auth);
  9616 
  9617 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  9618 the rewriter and classical reasoner simultaneously;
  9619 
  9620 * function uresult no longer returns theorems in "standard" format;
  9621 regain previous version by: val uresult = standard o uresult;
  9622 
  9623 
  9624 
  9625 New in Isabelle94-6
  9626 -------------------
  9627 
  9628 * oracles -- these establish an interface between Isabelle and trusted
  9629 external reasoners, which may deliver results as theorems;
  9630 
  9631 * proof objects (in particular record all uses of oracles);
  9632 
  9633 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  9634 
  9635 * "constdefs" section in theory files;
  9636 
  9637 * "primrec" section (HOL) no longer requires names;
  9638 
  9639 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  9640 
  9641 
  9642 
  9643 New in Isabelle94-5
  9644 -------------------
  9645 
  9646 * reduced space requirements;
  9647 
  9648 * automatic HTML generation from theories;
  9649 
  9650 * theory files no longer require "..." (quotes) around most types;
  9651 
  9652 * new examples, including two proofs of the Church-Rosser theorem;
  9653 
  9654 * non-curried (1994) version of HOL is no longer distributed;
  9655 
  9656 
  9657 
  9658 New in Isabelle94-4
  9659 -------------------
  9660 
  9661 * greatly reduced space requirements;
  9662 
  9663 * theory files (.thy) no longer require \...\ escapes at line breaks;
  9664 
  9665 * searchable theorem database (see the section "Retrieving theorems" on
  9666 page 8 of the Reference Manual);
  9667 
  9668 * new examples, including Grabczewski's monumental case study of the
  9669 Axiom of Choice;
  9670 
  9671 * The previous version of HOL renamed to Old_HOL;
  9672 
  9673 * The new version of HOL (previously called CHOL) uses a curried syntax
  9674 for functions.  Application looks like f a b instead of f(a,b);
  9675 
  9676 * Mutually recursive inductive definitions finally work in HOL;
  9677 
  9678 * In ZF, pattern-matching on tuples is now available in all abstractions and
  9679 translates to the operator "split";
  9680 
  9681 
  9682 
  9683 New in Isabelle94-3
  9684 -------------------
  9685 
  9686 * new infix operator, addss, allowing the classical reasoner to
  9687 perform simplification at each step of its search.  Example:
  9688         fast_tac (cs addss ss)
  9689 
  9690 * a new logic, CHOL, the same as HOL, but with a curried syntax
  9691 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  9692 look like (a,b) instead of <a,b>;
  9693 
  9694 * PLEASE NOTE: CHOL will eventually replace HOL!
  9695 
  9696 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  9697 It translates to the operator "split".  A new theory of integers is available;
  9698 
  9699 * In ZF, integer numerals now denote two's-complement binary integers.
  9700 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  9701 
  9702 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  9703 of the Axiom of Choice;
  9704 
  9705 
  9706 
  9707 New in Isabelle94-2
  9708 -------------------
  9709 
  9710 * Significantly faster resolution;
  9711 
  9712 * the different sections in a .thy file can now be mixed and repeated
  9713 freely;
  9714 
  9715 * Database of theorems for FOL, HOL and ZF.  New
  9716 commands including qed, qed_goal and bind_thm store theorems in the database.
  9717 
  9718 * Simple database queries: return a named theorem (get_thm) or all theorems of
  9719 a given theory (thms_of), or find out what theory a theorem was proved in
  9720 (theory_of_thm);
  9721 
  9722 * Bugs fixed in the inductive definition and datatype packages;
  9723 
  9724 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  9725 and HOL_dup_cs obsolete;
  9726 
  9727 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  9728 have been removed;
  9729 
  9730 * Simpler definition of function space in ZF;
  9731 
  9732 * new results about cardinal and ordinal arithmetic in ZF;
  9733 
  9734 * 'subtype' facility in HOL for introducing new types as subsets of existing
  9735 types;
  9736 
  9737 :mode=text:wrap=hard:maxLineLen=72: