NEWS
author bulwahn
Thu, 29 Mar 2012 17:40:44 +0200
changeset 48068 ed681ca1188a
parent 48056 300fa46fd081
child 48073 69cee87927f0
permissions -rw-r--r--
announcing NEWS (cf. 446cfc760ccf)
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Prover IDE (PIDE) improvements:
    10 
    11   - markup for bound variables
    12   - markup for types of term variables (e.g. displayed as tooltips)
    13   - support for user-defined Isar commands within the running session
    14   - improved support for Unicode outside original 16bit range
    15     e.g. glyph for \<A> (thanks to jEdit 4.5.1)
    16 
    17 * Updated and extended reference manuals ("isar-ref" and
    18 "implementation"); reduced remaining material in old "ref" manual.
    19 
    20 * Rule attributes in local theory declarations (e.g. locale or class)
    21 are now statically evaluated: the resulting theorem is stored instead
    22 of the original expression.  INCOMPATIBILITY in rare situations, where
    23 the historic accident of dynamic re-evaluation in interpretations
    24 etc. was exploited.
    25 
    26 * Commands 'lemmas' and 'theorems' allow local variables using 'for'
    27 declaration, and results are standardized before being stored.  Thus
    28 old-style "standard" after instantiation or composition of facts
    29 becomes obsolete.  Minor INCOMPATIBILITY, due to potential change of
    30 indices of schematic variables.
    31 
    32 * Renamed some inner syntax categories:
    33 
    34     num ~> num_token
    35     xnum ~> xnum_token
    36     xstr ~> str_token
    37 
    38 Minor INCOMPATIBILITY.  Note that in practice "num_const" or
    39 "num_position" etc. are mainly used instead (which also include
    40 position information via constraints).
    41 
    42 * Simplified configuration options for syntax ambiguity: see
    43 "syntax_ambiguity_warning" and "syntax_ambiguity_limit" in isar-ref
    44 manual.  Minor INCOMPATIBILITY.
    45 
    46 * Forward declaration of outer syntax keywords within the theory
    47 header -- minor INCOMPATIBILITY for user-defined commands.  Allow new
    48 commands to be used in the same theory where defined.
    49 
    50 * ISABELLE_JDK_HOME settings variable points to JDK with javac and jar
    51 (not just JRE).
    52 
    53 
    54 *** Pure ***
    55 
    56 * Command 'definition' no longer exports the foundational "raw_def"
    57 into the user context.  Minor INCOMPATIBILITY, may use the regular
    58 "def" result with attribute "abs_def" to imitate the old version.
    59 
    60 * Attribute "abs_def" turns an equation of the form "f x y == t" into
    61 "f == %x y. t", which ensures that "simp" or "unfold" steps always
    62 expand it.  This also works for object-logic equality.  (Formerly
    63 undocumented feature.)
    64 
    65 * Discontinued old "prems" fact, which used to refer to the accidental
    66 collection of foundational premises in the context (marked as legacy
    67 since Isabelle2011).
    68 
    69 * Obsolete command 'types' has been discontinued.  Use 'type_synonym'
    70 instead.  INCOMPATIBILITY.
    71 
    72 * Ancient code generator for SML and its commands 'code_module',
    73 'code_library', 'consts_code', 'types_code' have been discontinued.
    74 Use commands of the generic code generator instead.  INCOMPATIBILITY.
    75 
    76 * Redundant attribute 'code_inline' has been discontinued. Use
    77 'code_unfold' instead.  INCOMPATIBILITY.
    78 
    79 * Dropped attribute 'code_unfold_post' in favor of the its dual
    80 'code_abbrev', which yields a common pattern in definitions like
    81 
    82   definition [code_abbrev]: "f = t"
    83 
    84 INCOMPATIBILITY.
    85 
    86 * Sort constraints are now propagated in simultaneous statements, just
    87 like type constraints.  INCOMPATIBILITY in rare situations, where
    88 distinct sorts used to be assigned accidentally.  For example:
    89 
    90   lemma "P (x::'a::foo)" and "Q (y::'a::bar)"  -- "now illegal"
    91 
    92   lemma "P (x::'a)" and "Q (y::'a::bar)"
    93     -- "now uniform 'a::bar instead of default sort for first occurence (!)"
    94 
    95 
    96 *** HOL ***
    97 
    98 * The representation of numerals has changed. We now have a datatype
    99 "num" representing strictly positive binary numerals, along with
   100 functions "numeral :: num => 'a" and "neg_numeral :: num => 'a" to
   101 represent positive and negated numeric literals, respectively. (See
   102 definitions in Num.thy.) Potential INCOMPATIBILITY; some user theories
   103 may require adaptations:
   104 
   105   - Theorems with number_ring or number_semiring constraints: These
   106     classes are gone; use comm_ring_1 or comm_semiring_1 instead.
   107 
   108   - Theories defining numeric types: Remove number, number_semiring,
   109     and number_ring instances. Defer all theorems about numerals until
   110     after classes one and semigroup_add have been instantiated.
   111 
   112   - Numeral-only simp rules: Replace each rule having a "number_of v"
   113     pattern with two copies, one for numeral and one for neg_numeral.
   114 
   115   - Theorems about subclasses of semiring_1 or ring_1: These classes
   116     automatically support numerals now, so more simp rules and
   117     simprocs may now apply within the proof.
   118 
   119   - Definitions and theorems using old constructors Pls/Min/Bit0/Bit1:
   120     Redefine using other integer operations.
   121 
   122 * Type 'a set is now a proper type constructor (just as before
   123 Isabelle2008).  Definitions mem_def and Collect_def have disappeared.
   124 Non-trivial INCOMPATIBILITY.  For developments keeping predicates and
   125 sets separate, it is often sufficient to rephrase sets S accidentally
   126 used as predicates by "%x. x : S" and predicates P accidentally used
   127 as sets by "{x. P x}".  Corresponding proofs in a first step should be
   128 pruned from any tinkering with former theorems mem_def and
   129 Collect_def as far as possible.
   130 For developments which deliberately mixed predicates and
   131 sets, a planning step is necessary to determine what should become a
   132 predicate and what a set.  It can be helpful to carry out that step in
   133 Isabelle2011-1 before jumping right into the current release.
   134 
   135 * Code generation by default implements sets as container type rather
   136 than predicates.  INCOMPATIBILITY.
   137 
   138 * New type synonym 'a rel = ('a * 'a) set
   139 
   140 * Theory Divides: Discontinued redundant theorems about div and mod.
   141 INCOMPATIBILITY, use the corresponding generic theorems instead.
   142 
   143   DIVISION_BY_ZERO ~> div_by_0, mod_by_0
   144   zdiv_self ~> div_self
   145   zmod_self ~> mod_self
   146   zdiv_zero ~> div_0
   147   zmod_zero ~> mod_0
   148   zdiv_zmod_equality ~> div_mod_equality2
   149   zdiv_zmod_equality2 ~> div_mod_equality
   150   zmod_zdiv_trivial ~> mod_div_trivial
   151   zdiv_zminus_zminus ~> div_minus_minus
   152   zmod_zminus_zminus ~> mod_minus_minus
   153   zdiv_zminus2 ~> div_minus_right
   154   zmod_zminus2 ~> mod_minus_right
   155   zdiv_minus1_right ~> div_minus1_right
   156   zmod_minus1_right ~> mod_minus1_right
   157   zdvd_mult_div_cancel ~> dvd_mult_div_cancel
   158   zmod_zmult1_eq ~> mod_mult_right_eq
   159   zpower_zmod ~> power_mod
   160   zdvd_zmod ~> dvd_mod
   161   zdvd_zmod_imp_zdvd ~> dvd_mod_imp_dvd
   162   mod_mult_distrib ~> mult_mod_left
   163   mod_mult_distrib2 ~> mult_mod_right
   164 
   165 * More default pred/set conversions on a couple of relation operations
   166 and predicates.  Consolidation of some relation theorems:
   167 
   168   converse_def ~> converse_unfold
   169   rel_comp_def ~> rel_comp_unfold
   170   symp_def ~> (dropped, use symp_def and sym_def instead)
   171   transp_def ~> transp_trans
   172   Domain_def ~> Domain_unfold
   173   Range_def ~> Domain_converse [symmetric]
   174 
   175 Generalized theorems INF_INT_eq, INF_INT_eq2, SUP_UN_eq, SUP_UN_eq2.
   176 
   177 See theory "Relation" for examples for making use of pred/set conversions
   178 by means of attributes "to_set" and "to_pred".
   179 
   180 INCOMPATIBILITY.
   181 
   182 * Consolidated various theorem names relating to Finite_Set.fold
   183 combinator:
   184 
   185   inf_INFI_fold_inf ~> inf_INF_fold_inf
   186   sup_SUPR_fold_sup ~> sup_SUP_fold_sup
   187   INFI_fold_inf ~> INF_fold_inf
   188   SUPR_fold_sup ~> SUP_fold_sup
   189   union_set ~> union_set_fold
   190   minus_set ~> minus_set_fold
   191 
   192 INCOMPATIBILITY.
   193 
   194 * Consolidated theorem names concerning fold combinators:
   195 
   196   INFI_set_fold ~> INF_set_fold
   197   SUPR_set_fold ~> SUP_set_fold
   198   INF_code ~> INF_set_foldr
   199   SUP_code ~> SUP_set_foldr
   200   foldr.simps ~> foldr_Nil foldr_Cons (in point-free formulation)
   201   foldl.simps ~> foldl_Nil foldl_Cons
   202   foldr_fold_rev ~> foldr_def
   203   foldl_fold ~> foldl_def
   204 
   205 INCOMPATIBILITY.
   206 
   207 * Dropped rarely useful theorems concerning fold combinators:
   208 foldl_apply, foldl_fun_comm, foldl_rev, fold_weak_invariant,
   209 rev_foldl_cons, fold_set_remdups, fold_set, fold_set1,
   210 concat_conv_foldl, foldl_weak_invariant, foldl_invariant,
   211 foldr_invariant, foldl_absorb0, foldl_foldr1_lemma, foldl_foldr1,
   212 listsum_conv_fold, listsum_foldl, sort_foldl_insort.  INCOMPATIBILITY.
   213 Prefer "List.fold" with canonical argument order, or boil down
   214 "List.foldr" and "List.foldl" to "List.fold" by unfolding "foldr_def"
   215 and "foldl_def".  For the common phrases "%xs. List.foldr plus xs 0"
   216 and "List.foldl plus 0", prefer "List.listsum".
   217 
   218 * Congruence rules Option.map_cong and Option.bind_cong for recursion
   219 through option types.
   220 
   221 * Concrete syntax for case expressions includes constraints for source
   222 positions, and thus produces Prover IDE markup for its bindings.
   223 INCOMPATIBILITY for old-style syntax translations that augment the
   224 pattern notation; e.g. see src/HOL/HOLCF/One.thy for translations of
   225 one_case.
   226 
   227 * Discontinued configuration option "syntax_positions": atomic terms
   228 in parse trees are always annotated by position constraints.
   229 
   230 * Finite_Set.fold now qualified.  INCOMPATIBILITY.
   231 
   232 * Renamed some facts on canonical fold on lists, in order to avoid
   233 problems with interpretation involving corresponding facts on foldl
   234 with the same base names:
   235 
   236   fold_set_remdups ~> fold_set_fold_remdups
   237   fold_set ~> fold_set_fold
   238   fold1_set ~> fold1_set_fold
   239 
   240 INCOMPATIBILITY.
   241 
   242 * Renamed facts about the power operation on relations, i.e., relpow
   243   to match the constant's name:
   244   
   245   rel_pow_1 ~> relpow_1
   246   rel_pow_0_I ~> relpow_0_I
   247   rel_pow_Suc_I ~> relpow_Suc_I
   248   rel_pow_Suc_I2 ~> relpow_Suc_I2
   249   rel_pow_0_E ~> relpow_0_E
   250   rel_pow_Suc_E ~> relpow_Suc_E
   251   rel_pow_E ~> relpow_E
   252   rel_pow_Suc_D2 ~> relpow_Suc_D2
   253   rel_pow_Suc_E2 ~> relpow_Suc_E2 
   254   rel_pow_Suc_D2' ~> relpow_Suc_D2'
   255   rel_pow_E2 ~> relpow_E2
   256   rel_pow_add ~> relpow_add
   257   rel_pow_commute ~> relpow
   258   rel_pow_empty ~> relpow_empty:
   259   rtrancl_imp_UN_rel_pow ~> rtrancl_imp_UN_relpow
   260   rel_pow_imp_rtrancl ~> relpow_imp_rtrancl
   261   rtrancl_is_UN_rel_pow ~> rtrancl_is_UN_relpow
   262   rtrancl_imp_rel_pow ~> rtrancl_imp_relpow
   263   rel_pow_fun_conv ~> relpow_fun_conv
   264   rel_pow_finite_bounded1 ~> relpow_finite_bounded1
   265   rel_pow_finite_bounded ~> relpow_finite_bounded
   266   rtrancl_finite_eq_rel_pow ~> rtrancl_finite_eq_relpow
   267   trancl_finite_eq_rel_pow ~> trancl_finite_eq_relpow
   268   single_valued_rel_pow ~> single_valued_relpow
   269  
   270 INCOMPATIBILITY.
   271 
   272 * New theory HOL/Library/DAList provides an abstract type for association
   273   lists with distinct keys.
   274 
   275 * 'datatype' specifications allow explicit sort constraints.
   276 
   277 * Theory HOL/Library/Diagonalize has been removed. INCOMPATIBILITY,
   278 use theory HOL/Library/Nat_Bijection instead.
   279 
   280 * Session HOL-Word: Discontinued many redundant theorems specific to
   281 type 'a word. INCOMPATIBILITY, use the corresponding generic theorems
   282 instead.
   283 
   284   word_sub_alt ~> word_sub_wi
   285   word_add_alt ~> word_add_def
   286   word_mult_alt ~> word_mult_def
   287   word_minus_alt ~> word_minus_def
   288   word_0_alt ~> word_0_wi
   289   word_1_alt ~> word_1_wi
   290   word_add_0 ~> add_0_left
   291   word_add_0_right ~> add_0_right
   292   word_mult_1 ~> mult_1_left
   293   word_mult_1_right ~> mult_1_right
   294   word_add_commute ~> add_commute
   295   word_add_assoc ~> add_assoc
   296   word_add_left_commute ~> add_left_commute
   297   word_mult_commute ~> mult_commute
   298   word_mult_assoc ~> mult_assoc
   299   word_mult_left_commute ~> mult_left_commute
   300   word_left_distrib ~> left_distrib
   301   word_right_distrib ~> right_distrib
   302   word_left_minus ~> left_minus
   303   word_diff_0_right ~> diff_0_right
   304   word_diff_self ~> diff_self
   305   word_sub_def ~> diff_minus
   306   word_diff_minus ~> diff_minus
   307   word_add_ac ~> add_ac
   308   word_mult_ac ~> mult_ac
   309   word_plus_ac0 ~> add_0_left add_0_right add_ac
   310   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
   311   word_order_trans ~> order_trans
   312   word_order_refl ~> order_refl
   313   word_order_antisym ~> order_antisym
   314   word_order_linear ~> linorder_linear
   315   lenw1_zero_neq_one ~> zero_neq_one
   316   word_number_of_eq ~> number_of_eq
   317   word_of_int_add_hom ~> wi_hom_add
   318   word_of_int_sub_hom ~> wi_hom_sub
   319   word_of_int_mult_hom ~> wi_hom_mult
   320   word_of_int_minus_hom ~> wi_hom_neg
   321   word_of_int_succ_hom ~> wi_hom_succ
   322   word_of_int_pred_hom ~> wi_hom_pred
   323   word_of_int_0_hom ~> word_0_wi
   324   word_of_int_1_hom ~> word_1_wi
   325 
   326 * Clarified attribute "mono_set": pure declaration without modifying
   327 the result of the fact expression.
   328 
   329 * "Transitive_Closure.ntrancl": bounded transitive closure on
   330 relations.
   331 
   332 * Constant "Set.not_member" now qualified.  INCOMPATIBILITY.
   333 
   334 * "sublists" moved to theory More_List.  INCOMPATIBILITY.
   335 
   336 * Theory Int: Discontinued many legacy theorems specific to type int.
   337 INCOMPATIBILITY, use the corresponding generic theorems instead.
   338 
   339   zminus_zminus ~> minus_minus
   340   zminus_0 ~> minus_zero
   341   zminus_zadd_distrib ~> minus_add_distrib
   342   zadd_commute ~> add_commute
   343   zadd_assoc ~> add_assoc
   344   zadd_left_commute ~> add_left_commute
   345   zadd_ac ~> add_ac
   346   zmult_ac ~> mult_ac
   347   zadd_0 ~> add_0_left
   348   zadd_0_right ~> add_0_right
   349   zadd_zminus_inverse2 ~> left_minus
   350   zmult_zminus ~> mult_minus_left
   351   zmult_commute ~> mult_commute
   352   zmult_assoc ~> mult_assoc
   353   zadd_zmult_distrib ~> left_distrib
   354   zadd_zmult_distrib2 ~> right_distrib
   355   zdiff_zmult_distrib ~> left_diff_distrib
   356   zdiff_zmult_distrib2 ~> right_diff_distrib
   357   zmult_1 ~> mult_1_left
   358   zmult_1_right ~> mult_1_right
   359   zle_refl ~> order_refl
   360   zle_trans ~> order_trans
   361   zle_antisym ~> order_antisym
   362   zle_linear ~> linorder_linear
   363   zless_linear ~> linorder_less_linear
   364   zadd_left_mono ~> add_left_mono
   365   zadd_strict_right_mono ~> add_strict_right_mono
   366   zadd_zless_mono ~> add_less_le_mono
   367   int_0_less_1 ~> zero_less_one
   368   int_0_neq_1 ~> zero_neq_one
   369   zless_le ~> less_le
   370   zpower_zadd_distrib ~> power_add
   371   zero_less_zpower_abs_iff ~> zero_less_power_abs_iff
   372   zero_le_zpower_abs ~> zero_le_power_abs
   373 
   374 * Theory Deriv: Renamed
   375 
   376   DERIV_nonneg_imp_nonincreasing ~> DERIV_nonneg_imp_nondecreasing
   377 
   378 * New "case_product" attribute to generate a case rule doing multiple
   379 case distinctions at the same time.  E.g.
   380 
   381   list.exhaust [case_product nat.exhaust]
   382 
   383 produces a rule which can be used to perform case distinction on both
   384 a list and a nat.
   385 
   386 * Improved code generation of multisets.
   387 
   388 * New diagnostic command find_unused_assms to find potentially superfluous
   389   assumptions in theorems using Quickcheck.
   390 
   391 * Quickcheck:
   392   - Quickcheck returns variable assignments as counterexamples, which
   393     allows to reveal the underspecification of functions under test.
   394     For example, refuting "hd xs = x", it presents the variable
   395     assignment xs = [] and x = a1 as a counterexample, assuming that
   396     any property is false whenever "hd []" occurs in it.
   397     These counterexample are marked as potentially spurious, as
   398     Quickcheck also returns "xs = []" as a counterexample to the
   399     obvious theorem "hd xs = hd xs".
   400     After finding a potentially spurious counterexample, Quickcheck
   401     continues searching for genuine ones.
   402     By default, Quickcheck shows potentially spurious and genuine
   403     counterexamples. The option "genuine_only" sets quickcheck to
   404     only show genuine counterexamples.
   405 
   406   - The command 'quickcheck_generator' creates random and exhaustive
   407     value generators for a given type and operations.
   408     It generates values by using the operations as if they were
   409     constructors of that type. 
   410 
   411   - Support for multisets.
   412 
   413   - Added "use_subtype" options.
   414  
   415 * Nitpick:
   416   - Fixed infinite loop caused by the 'peephole_optim' option and
   417     affecting 'rat' and 'real'.
   418 
   419 * Sledgehammer:
   420   - Added "lam_trans", "uncurry_aliases", and "minimize" options.
   421   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   422   - Renamed "sound" option to "strict".
   423 
   424 * Metis:
   425   - Added possibility to specify lambda translations scheme as a
   426     parenthesized argument (e.g., "by (metis (lifting) ...)").
   427 
   428 * SMT:
   429   - renamed "smt_fixed" option to "smt_read_only_certificates".
   430  
   431 * Command 'try0':
   432   - Renamed from 'try_methods'. INCOMPATIBILITY.
   433 
   434 * New "eventually_elim" method as a generalized variant of the
   435   eventually_elim* rules. Supports structured proofs.
   436 
   437 
   438 *** FOL ***
   439 
   440 * New "case_product" attribute (see HOL).
   441 
   442 
   443 *** ML ***
   444 
   445 * Antiquotation @{keyword "name"} produces a parser for outer syntax
   446 from a minor keyword introduced via theory header declaration.
   447 
   448 * Antiquotation @{command_spec "name"} produces the
   449 Outer_Syntax.command_spec from a major keyword introduced via theory
   450 header declaration; it can be passed to Outer_Syntax.command etc.
   451 
   452 * Local_Theory.define no longer hard-wires default theorem name
   453 "foo_def", but retains the binding as given.  If that is Binding.empty
   454 / Attrib.empty_binding, the result is not registered as user-level
   455 fact.  The Local_Theory.define_internal variant allows to specify a
   456 non-empty name (used for the foundation in the background theory),
   457 while omitting the fact binding in the user-context.  Potential
   458 INCOMPATIBILITY for derived definitional packages: need to specify
   459 naming policy for primitive definitions more explicitly.
   460 
   461 * Renamed Thm.capply to Thm.apply, and Thm.cabs to Thm.lambda in
   462 conformance with similar operations in structure Term and Logic.
   463 
   464 * Antiquotation @{attributes [...]} embeds attribute source
   465 representation into the ML text, which is particularly useful with
   466 declarations like Local_Theory.note.
   467 
   468 * Structure Proof_Context follows standard naming scheme.  Old
   469 ProofContext has been discontinued.  INCOMPATIBILITY.
   470 
   471 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
   472 change of semantics: update is applied to auxiliary local theory
   473 context as well.
   474 
   475 * Modernized some old-style infix operations:
   476 
   477   addeqcongs    ~> Simplifier.add_eqcong
   478   deleqcongs    ~> Simplifier.del_eqcong
   479   addcongs      ~> Simplifier.add_cong
   480   delcongs      ~> Simplifier.del_cong
   481   setmksimps    ~> Simplifier.set_mksimps
   482   setmkcong     ~> Simplifier.set_mkcong
   483   setmksym      ~> Simplifier.set_mksym
   484   setmkeqTrue   ~> Simplifier.set_mkeqTrue
   485   settermless   ~> Simplifier.set_termless
   486   setsubgoaler  ~> Simplifier.set_subgoaler
   487   addsplits     ~> Splitter.add_split
   488   delsplits     ~> Splitter.del_split
   489 
   490 
   491 
   492 New in Isabelle2011-1 (October 2011)
   493 ------------------------------------
   494 
   495 *** General ***
   496 
   497 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
   498 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
   499 
   500   - Management of multiple theory files directly from the editor
   501     buffer store -- bypassing the file-system (no requirement to save
   502     files for checking).
   503 
   504   - Markup of formal entities within the text buffer, with semantic
   505     highlighting, tooltips and hyperlinks to jump to defining source
   506     positions.
   507 
   508   - Improved text rendering, with sub/superscripts in the source
   509     buffer (including support for copy/paste wrt. output panel, HTML
   510     theory output and other non-Isabelle text boxes).
   511 
   512   - Refined scheduling of proof checking and printing of results,
   513     based on interactive editor view.  (Note: jEdit folding and
   514     narrowing allows to restrict buffer perspectives explicitly.)
   515 
   516   - Reduced CPU performance requirements, usable on machines with few
   517     cores.
   518 
   519   - Reduced memory requirements due to pruning of unused document
   520     versions (garbage collection).
   521 
   522 See also ~~/src/Tools/jEdit/README.html for further information,
   523 including some remaining limitations.
   524 
   525 * Theory loader: source files are exclusively located via the master
   526 directory of each theory node (where the .thy file itself resides).
   527 The global load path (such as src/HOL/Library) has been discontinued.
   528 Note that the path element ~~ may be used to reference theories in the
   529 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
   530 INCOMPATIBILITY.
   531 
   532 * Theory loader: source files are identified by content via SHA1
   533 digests.  Discontinued former path/modtime identification and optional
   534 ISABELLE_FILE_IDENT plugin scripts.
   535 
   536 * Parallelization of nested Isar proofs is subject to
   537 Goal.parallel_proofs_threshold (default 100).  See also isabelle
   538 usedir option -Q.
   539 
   540 * Name space: former unsynchronized references are now proper
   541 configuration options, with more conventional names:
   542 
   543   long_names   ~> names_long
   544   short_names  ~> names_short
   545   unique_names ~> names_unique
   546 
   547 Minor INCOMPATIBILITY, need to declare options in context like this:
   548 
   549   declare [[names_unique = false]]
   550 
   551 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
   552 that the result needs to be unique, which means fact specifications
   553 may have to be refined after enriching a proof context.
   554 
   555 * Attribute "case_names" has been refined: the assumptions in each case
   556 can be named now by following the case name with [name1 name2 ...].
   557 
   558 * Isabelle/Isar reference manual has been updated and extended:
   559   - "Synopsis" provides a catalog of main Isar language concepts.
   560   - Formal references in syntax diagrams, via @{rail} antiquotation.
   561   - Updated material from classic "ref" manual, notably about
   562     "Classical Reasoner".
   563 
   564 
   565 *** HOL ***
   566 
   567 * Class bot and top require underlying partial order rather than
   568 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
   569 
   570 * Class complete_lattice: generalized a couple of lemmas from sets;
   571 generalized theorems INF_cong and SUP_cong.  New type classes for
   572 complete boolean algebras and complete linear orders.  Lemmas
   573 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
   574 class complete_linorder.
   575 
   576 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
   577 Sup_fun_def, Inf_apply, Sup_apply.
   578 
   579 Removed redundant lemmas (the right hand side gives hints how to
   580 replace them for (metis ...), or (simp only: ...) proofs):
   581 
   582   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
   583   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
   584   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
   585   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
   586   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
   587   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
   588   Inter_def ~> INF_def, image_def
   589   Union_def ~> SUP_def, image_def
   590   INT_eq ~> INF_def, and image_def
   591   UN_eq ~> SUP_def, and image_def
   592   INF_subset ~> INF_superset_mono [OF _ order_refl]
   593 
   594 More consistent and comprehensive names:
   595 
   596   INTER_eq_Inter_image ~> INF_def
   597   UNION_eq_Union_image ~> SUP_def
   598   INFI_def ~> INF_def
   599   SUPR_def ~> SUP_def
   600   INF_leI ~> INF_lower
   601   INF_leI2 ~> INF_lower2
   602   le_INFI ~> INF_greatest
   603   le_SUPI ~> SUP_upper
   604   le_SUPI2 ~> SUP_upper2
   605   SUP_leI ~> SUP_least
   606   INFI_bool_eq ~> INF_bool_eq
   607   SUPR_bool_eq ~> SUP_bool_eq
   608   INFI_apply ~> INF_apply
   609   SUPR_apply ~> SUP_apply
   610   INTER_def ~> INTER_eq
   611   UNION_def ~> UNION_eq
   612 
   613 INCOMPATIBILITY.
   614 
   615 * Renamed theory Complete_Lattice to Complete_Lattices.
   616 INCOMPATIBILITY.
   617 
   618 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
   619 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
   620 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
   621 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
   622 
   623 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
   624 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
   625 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
   626 INCOMPATIBILITY.
   627 
   628 * Added syntactic classes "inf" and "sup" for the respective
   629 constants.  INCOMPATIBILITY: Changes in the argument order of the
   630 (mostly internal) locale predicates for some derived classes.
   631 
   632 * Theorem collections ball_simps and bex_simps do not contain theorems
   633 referring to UNION any longer; these have been moved to collection
   634 UN_ball_bex_simps.  INCOMPATIBILITY.
   635 
   636 * Theory Archimedean_Field: floor now is defined as parameter of a
   637 separate type class floor_ceiling.
   638 
   639 * Theory Finite_Set: more coherent development of fold_set locales:
   640 
   641     locale fun_left_comm ~> locale comp_fun_commute
   642     locale fun_left_comm_idem ~> locale comp_fun_idem
   643 
   644 Both use point-free characterization; interpretation proofs may need
   645 adjustment.  INCOMPATIBILITY.
   646 
   647 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
   648 accordance with standard mathematical terminology. INCOMPATIBILITY.
   649 
   650 * Theory Complex_Main: The locale interpretations for the
   651 bounded_linear and bounded_bilinear locales have been removed, in
   652 order to reduce the number of duplicate lemmas. Users must use the
   653 original names for distributivity theorems, potential INCOMPATIBILITY.
   654 
   655   divide.add ~> add_divide_distrib
   656   divide.diff ~> diff_divide_distrib
   657   divide.setsum ~> setsum_divide_distrib
   658   mult.add_right ~> right_distrib
   659   mult.diff_right ~> right_diff_distrib
   660   mult_right.setsum ~> setsum_right_distrib
   661   mult_left.diff ~> left_diff_distrib
   662 
   663 * Theory Complex_Main: Several redundant theorems have been removed or
   664 replaced by more general versions. INCOMPATIBILITY.
   665 
   666   real_diff_def ~> minus_real_def
   667   real_divide_def ~> divide_real_def
   668   real_less_def ~> less_le
   669   real_abs_def ~> abs_real_def
   670   real_sgn_def ~> sgn_real_def
   671   real_mult_commute ~> mult_commute
   672   real_mult_assoc ~> mult_assoc
   673   real_mult_1 ~> mult_1_left
   674   real_add_mult_distrib ~> left_distrib
   675   real_zero_not_eq_one ~> zero_neq_one
   676   real_mult_inverse_left ~> left_inverse
   677   INVERSE_ZERO ~> inverse_zero
   678   real_le_refl ~> order_refl
   679   real_le_antisym ~> order_antisym
   680   real_le_trans ~> order_trans
   681   real_le_linear ~> linear
   682   real_le_eq_diff ~> le_iff_diff_le_0
   683   real_add_left_mono ~> add_left_mono
   684   real_mult_order ~> mult_pos_pos
   685   real_mult_less_mono2 ~> mult_strict_left_mono
   686   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
   687   real_0_le_divide_iff ~> zero_le_divide_iff
   688   realpow_two_disj ~> power2_eq_iff
   689   real_squared_diff_one_factored ~> square_diff_one_factored
   690   realpow_two_diff ~> square_diff_square_factored
   691   reals_complete2 ~> complete_real
   692   real_sum_squared_expand ~> power2_sum
   693   exp_ln_eq ~> ln_unique
   694   expi_add ~> exp_add
   695   expi_zero ~> exp_zero
   696   lemma_DERIV_subst ~> DERIV_cong
   697   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
   698   LIMSEQ_const ~> tendsto_const
   699   LIMSEQ_norm ~> tendsto_norm
   700   LIMSEQ_add ~> tendsto_add
   701   LIMSEQ_minus ~> tendsto_minus
   702   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
   703   LIMSEQ_diff ~> tendsto_diff
   704   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
   705   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
   706   LIMSEQ_mult ~> tendsto_mult
   707   LIMSEQ_inverse ~> tendsto_inverse
   708   LIMSEQ_divide ~> tendsto_divide
   709   LIMSEQ_pow ~> tendsto_power
   710   LIMSEQ_setsum ~> tendsto_setsum
   711   LIMSEQ_setprod ~> tendsto_setprod
   712   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
   713   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
   714   LIMSEQ_imp_rabs ~> tendsto_rabs
   715   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
   716   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
   717   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
   718   LIMSEQ_Complex ~> tendsto_Complex
   719   LIM_ident ~> tendsto_ident_at
   720   LIM_const ~> tendsto_const
   721   LIM_add ~> tendsto_add
   722   LIM_add_zero ~> tendsto_add_zero
   723   LIM_minus ~> tendsto_minus
   724   LIM_diff ~> tendsto_diff
   725   LIM_norm ~> tendsto_norm
   726   LIM_norm_zero ~> tendsto_norm_zero
   727   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
   728   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
   729   LIM_rabs ~> tendsto_rabs
   730   LIM_rabs_zero ~> tendsto_rabs_zero
   731   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
   732   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
   733   LIM_compose ~> tendsto_compose
   734   LIM_mult ~> tendsto_mult
   735   LIM_scaleR ~> tendsto_scaleR
   736   LIM_of_real ~> tendsto_of_real
   737   LIM_power ~> tendsto_power
   738   LIM_inverse ~> tendsto_inverse
   739   LIM_sgn ~> tendsto_sgn
   740   isCont_LIM_compose ~> isCont_tendsto_compose
   741   bounded_linear.LIM ~> bounded_linear.tendsto
   742   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
   743   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
   744   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
   745   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
   746   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
   747   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
   748 
   749 * Theory Complex_Main: The definition of infinite series was
   750 generalized.  Now it is defined on the type class {topological_space,
   751 comm_monoid_add}.  Hence it is useable also for extended real numbers.
   752 
   753 * Theory Complex_Main: The complex exponential function "expi" is now
   754 a type-constrained abbreviation for "exp :: complex => complex"; thus
   755 several polymorphic lemmas about "exp" are now applicable to "expi".
   756 
   757 * Code generation:
   758 
   759   - Theory Library/Code_Char_ord provides native ordering of
   760     characters in the target language.
   761 
   762   - Commands code_module and code_library are legacy, use export_code
   763     instead.
   764 
   765   - Method "evaluation" is legacy, use method "eval" instead.
   766 
   767   - Legacy evaluator "SML" is deactivated by default.  May be
   768     reactivated by the following theory command:
   769 
   770       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   771 
   772 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   773 
   774 * New proof method "induction" that gives induction hypotheses the
   775 name "IH", thus distinguishing them from further hypotheses that come
   776 from rule induction.  The latter are still called "hyps".  Method
   777 "induction" is a thin wrapper around "induct" and follows the same
   778 syntax.
   779 
   780 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
   781 still available as a legacy feature for some time.
   782 
   783 * Nitpick:
   784   - Added "need" and "total_consts" options.
   785   - Reintroduced "show_skolems" option by popular demand.
   786   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   787     INCOMPATIBILITY.
   788 
   789 * Sledgehammer:
   790   - Use quasi-sound (and efficient) translations by default.
   791   - Added support for the following provers: E-ToFoF, LEO-II,
   792     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
   793   - Automatically preplay and minimize proofs before showing them if
   794     this can be done within reasonable time.
   795   - sledgehammer available_provers ~> sledgehammer supported_provers.
   796     INCOMPATIBILITY.
   797   - Added "preplay_timeout", "slicing", "type_enc", "sound",
   798     "max_mono_iters", and "max_new_mono_instances" options.
   799   - Removed "explicit_apply" and "full_types" options as well as "Full
   800     Types" Proof General menu item. INCOMPATIBILITY.
   801 
   802 * Metis:
   803   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   804   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
   805     INCOMPATIBILITY.
   806 
   807 * Command 'try':
   808   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
   809     "elim:" options. INCOMPATIBILITY.
   810   - Introduced 'try' that not only runs 'try_methods' but also
   811     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
   812 
   813 * Quickcheck:
   814   - Added "eval" option to evaluate terms for the found counterexample
   815     (currently only supported by the default (exhaustive) tester).
   816   - Added post-processing of terms to obtain readable counterexamples
   817     (currently only supported by the default (exhaustive) tester).
   818   - New counterexample generator quickcheck[narrowing] enables
   819     narrowing-based testing.  Requires the Glasgow Haskell compiler
   820     with its installation location defined in the Isabelle settings
   821     environment as ISABELLE_GHC.
   822   - Removed quickcheck tester "SML" based on the SML code generator
   823     (formly in HOL/Library).
   824 
   825 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
   826 use 'partial_function' instead.
   827 
   828 * Theory Library/Extended_Reals replaces now the positive extended
   829 reals found in probability theory. This file is extended by
   830 Multivariate_Analysis/Extended_Real_Limits.
   831 
   832 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
   833 from where it must be imported explicitly if it is really required.
   834 INCOMPATIBILITY.
   835 
   836 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
   837 been moved here.  INCOMPATIBILITY.
   838 
   839 * Theory Library/Saturated provides type of numbers with saturated
   840 arithmetic.
   841 
   842 * Theory Library/Product_Lattice defines a pointwise ordering for the
   843 product type 'a * 'b, and provides instance proofs for various order
   844 and lattice type classes.
   845 
   846 * Theory Library/Countable now provides the "countable_datatype" proof
   847 method for proving "countable" class instances for datatypes.
   848 
   849 * Theory Library/Cset_Monad allows do notation for computable sets
   850 (cset) via the generic monad ad-hoc overloading facility.
   851 
   852 * Library: Theories of common data structures are split into theories
   853 for implementation, an invariant-ensuring type, and connection to an
   854 abstract type. INCOMPATIBILITY.
   855 
   856   - RBT is split into RBT and RBT_Mapping.
   857   - AssocList is split and renamed into AList and AList_Mapping.
   858   - DList is split into DList_Impl, DList, and DList_Cset.
   859   - Cset is split into Cset and List_Cset.
   860 
   861 * Theory Library/Nat_Infinity has been renamed to
   862 Library/Extended_Nat, with name changes of the following types and
   863 constants:
   864 
   865   type inat   ~> type enat
   866   Fin         ~> enat
   867   Infty       ~> infinity (overloaded)
   868   iSuc        ~> eSuc
   869   the_Fin     ~> the_enat
   870 
   871 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   872 been renamed accordingly. INCOMPATIBILITY.
   873 
   874 * Session Multivariate_Analysis: The euclidean_space type class now
   875 fixes a constant "Basis :: 'a set" consisting of the standard
   876 orthonormal basis for the type. Users now have the option of
   877 quantifying over this set instead of using the "basis" function, e.g.
   878 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
   879 
   880 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   881 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   882 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   883 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   884 changed to match. Definition theorems for overloaded constants now use
   885 the standard "foo_vec_def" naming scheme. A few other theorems have
   886 been renamed as follows (INCOMPATIBILITY):
   887 
   888   Cart_eq          ~> vec_eq_iff
   889   dist_nth_le_cart ~> dist_vec_nth_le
   890   tendsto_vector   ~> vec_tendstoI
   891   Cauchy_vector    ~> vec_CauchyI
   892 
   893 * Session Multivariate_Analysis: Several duplicate theorems have been
   894 removed, and other theorems have been renamed or replaced with more
   895 general versions. INCOMPATIBILITY.
   896 
   897   finite_choice ~> finite_set_choice
   898   eventually_conjI ~> eventually_conj
   899   eventually_and ~> eventually_conj_iff
   900   eventually_false ~> eventually_False
   901   setsum_norm ~> norm_setsum
   902   Lim_sequentially ~> LIMSEQ_def
   903   Lim_ident_at ~> LIM_ident
   904   Lim_const ~> tendsto_const
   905   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
   906   Lim_neg ~> tendsto_minus
   907   Lim_add ~> tendsto_add
   908   Lim_sub ~> tendsto_diff
   909   Lim_mul ~> tendsto_scaleR
   910   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
   911   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
   912   Lim_linear ~> bounded_linear.tendsto
   913   Lim_component ~> tendsto_euclidean_component
   914   Lim_component_cart ~> tendsto_vec_nth
   915   Lim_inner ~> tendsto_inner [OF tendsto_const]
   916   dot_lsum ~> inner_setsum_left
   917   dot_rsum ~> inner_setsum_right
   918   continuous_cmul ~> continuous_scaleR [OF continuous_const]
   919   continuous_neg ~> continuous_minus
   920   continuous_sub ~> continuous_diff
   921   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
   922   continuous_mul ~> continuous_scaleR
   923   continuous_inv ~> continuous_inverse
   924   continuous_at_within_inv ~> continuous_at_within_inverse
   925   continuous_at_inv ~> continuous_at_inverse
   926   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
   927   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
   928   continuous_at_component ~> continuous_component [OF continuous_at_id]
   929   continuous_on_neg ~> continuous_on_minus
   930   continuous_on_sub ~> continuous_on_diff
   931   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
   932   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
   933   continuous_on_mul ~> continuous_on_scaleR
   934   continuous_on_mul_real ~> continuous_on_mult
   935   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
   936   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
   937   continuous_on_inverse ~> continuous_on_inv
   938   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
   939   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
   940   subset_interior ~> interior_mono
   941   subset_closure ~> closure_mono
   942   closure_univ ~> closure_UNIV
   943   real_arch_lt ~> reals_Archimedean2
   944   real_arch ~> reals_Archimedean3
   945   real_abs_norm ~> abs_norm_cancel
   946   real_abs_sub_norm ~> norm_triangle_ineq3
   947   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
   948 
   949 * Session HOL-Probability:
   950   - Caratheodory's extension lemma is now proved for ring_of_sets.
   951   - Infinite products of probability measures are now available.
   952   - Sigma closure is independent, if the generator is independent
   953   - Use extended reals instead of positive extended
   954     reals. INCOMPATIBILITY.
   955 
   956 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
   957 
   958   expand_fun_below ~> fun_below_iff
   959   below_fun_ext ~> fun_belowI
   960   expand_cfun_eq ~> cfun_eq_iff
   961   ext_cfun ~> cfun_eqI
   962   expand_cfun_below ~> cfun_below_iff
   963   below_cfun_ext ~> cfun_belowI
   964   monofun_fun_fun ~> fun_belowD
   965   monofun_fun_arg ~> monofunE
   966   monofun_lub_fun ~> adm_monofun [THEN admD]
   967   cont_lub_fun ~> adm_cont [THEN admD]
   968   cont2cont_Rep_CFun ~> cont2cont_APP
   969   cont_Rep_CFun_app ~> cont_APP_app
   970   cont_Rep_CFun_app_app ~> cont_APP_app_app
   971   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
   972   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
   973   contlub_cfun ~> lub_APP [symmetric]
   974   contlub_LAM ~> lub_LAM [symmetric]
   975   thelubI ~> lub_eqI
   976   UU_I ~> bottomI
   977   lift_distinct1 ~> lift.distinct(1)
   978   lift_distinct2 ~> lift.distinct(2)
   979   Def_not_UU ~> lift.distinct(2)
   980   Def_inject ~> lift.inject
   981   below_UU_iff ~> below_bottom_iff
   982   eq_UU_iff ~> eq_bottom_iff
   983 
   984 
   985 *** Document preparation ***
   986 
   987 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   988 isar-ref manual, both for description and actual application of the
   989 same.
   990 
   991 * Antiquotation @{value} evaluates the given term and presents its
   992 result.
   993 
   994 * Antiquotations: term style "isub" provides ad-hoc conversion of
   995 variables x1, y23 into subscripted form x\<^isub>1,
   996 y\<^isub>2\<^isub>3.
   997 
   998 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   999 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
  1000 
  1001 * Localized \isabellestyle switch can be used within blocks or groups
  1002 like this:
  1003 
  1004   \isabellestyle{it}  %preferred default
  1005   {\isabellestylett @{text "typewriter stuff"}}
  1006 
  1007 * Discontinued special treatment of hard tabulators.  Implicit
  1008 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
  1009 layouts.
  1010 
  1011 
  1012 *** ML ***
  1013 
  1014 * The inner syntax of sort/type/term/prop supports inlined YXML
  1015 representations within quoted string tokens.  By encoding logical
  1016 entities via Term_XML (in ML or Scala) concrete syntax can be
  1017 bypassed, which is particularly useful for producing bits of text
  1018 under external program control.
  1019 
  1020 * Antiquotations for ML and document preparation are managed as theory
  1021 data, which requires explicit setup.
  1022 
  1023 * Isabelle_Process.is_active allows tools to check if the official
  1024 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
  1025 (better known as Proof General).
  1026 
  1027 * Structure Proof_Context follows standard naming scheme.  Old
  1028 ProofContext is still available for some time as legacy alias.
  1029 
  1030 * Structure Timing provides various operations for timing; supersedes
  1031 former start_timing/end_timing etc.
  1032 
  1033 * Path.print is the official way to show file-system paths to users
  1034 (including quotes etc.).
  1035 
  1036 * Inner syntax: identifiers in parse trees of generic categories
  1037 "logic", "aprop", "idt" etc. carry position information (disguised as
  1038 type constraints).  Occasional INCOMPATIBILITY with non-compliant
  1039 translations that choke on unexpected type constraints.  Positions can
  1040 be stripped in ML translations via Syntax.strip_positions /
  1041 Syntax.strip_positions_ast, or via the syntax constant
  1042 "_strip_positions" within parse trees.  As last resort, positions can
  1043 be disabled via the configuration option Syntax.positions, which is
  1044 called "syntax_positions" in Isar attribute syntax.
  1045 
  1046 * Discontinued special status of various ML structures that contribute
  1047 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
  1048 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
  1049 refer directly to Ast.Constant, Lexicon.is_identifier,
  1050 Syntax_Trans.mk_binder_tr etc.
  1051 
  1052 * Typed print translation: discontinued show_sorts argument, which is
  1053 already available via context of "advanced" translation.
  1054 
  1055 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
  1056 goal states; body tactic needs to address all subgoals uniformly.
  1057 
  1058 * Slightly more special eq_list/eq_set, with shortcut involving
  1059 pointer equality (assumes that eq relation is reflexive).
  1060 
  1061 * Classical tactics use proper Proof.context instead of historic types
  1062 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
  1063 operate directly on Proof.context.  Raw type claset retains its use as
  1064 snapshot of the classical context, which can be recovered via
  1065 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
  1066 INCOMPATIBILITY, classical tactics and derived proof methods require
  1067 proper Proof.context.
  1068 
  1069 
  1070 *** System ***
  1071 
  1072 * Discontinued support for Poly/ML 5.2, which was the last version
  1073 without proper multithreading and TimeLimit implementation.
  1074 
  1075 * Discontinued old lib/scripts/polyml-platform, which has been
  1076 obsolete since Isabelle2009-2.
  1077 
  1078 * Various optional external tools are referenced more robustly and
  1079 uniformly by explicit Isabelle settings as follows:
  1080 
  1081   ISABELLE_CSDP   (formerly CSDP_EXE)
  1082   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  1083   ISABELLE_OCAML  (formerly EXEC_OCAML)
  1084   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  1085   ISABELLE_YAP    (formerly EXEC_YAP)
  1086 
  1087 Note that automated detection from the file-system or search path has
  1088 been discontinued.  INCOMPATIBILITY.
  1089 
  1090 * Scala layer provides JVM method invocation service for static
  1091 methods of type (String)String, see Invoke_Scala.method in ML.  For
  1092 example:
  1093 
  1094   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
  1095 
  1096 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
  1097 this allows to pass structured values between ML and Scala.
  1098 
  1099 * The IsabelleText fonts includes some further glyphs to support the
  1100 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
  1101 installed a local copy (which is normally *not* required) need to
  1102 delete or update it from ~~/lib/fonts/.
  1103 
  1104 
  1105 
  1106 New in Isabelle2011 (January 2011)
  1107 ----------------------------------
  1108 
  1109 *** General ***
  1110 
  1111 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
  1112 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
  1113 useful tooltips and hyperlinks produced from its static analysis.  The
  1114 bundled component provides an executable Isabelle tool that can be run
  1115 like this:
  1116 
  1117   Isabelle2011/bin/isabelle jedit
  1118 
  1119 * Significantly improved Isabelle/Isar implementation manual.
  1120 
  1121 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
  1122 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
  1123 while the default heap location within that directory lacks that extra
  1124 suffix.  This isolates multiple Isabelle installations from each
  1125 other, avoiding problems with old settings in new versions.
  1126 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
  1127 
  1128 * Source files are always encoded as UTF-8, instead of old-fashioned
  1129 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
  1130 the following package declarations:
  1131 
  1132   \usepackage[utf8]{inputenc}
  1133   \usepackage{textcomp}
  1134 
  1135 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
  1136 a Unicode character is treated as a single symbol, not a sequence of
  1137 non-ASCII bytes as before.  Since Isabelle/ML string literals may
  1138 contain symbols without further backslash escapes, Unicode can now be
  1139 used here as well.  Recall that Symbol.explode in ML provides a
  1140 consistent view on symbols, while raw explode (or String.explode)
  1141 merely give a byte-oriented representation.
  1142 
  1143 * Theory loader: source files are primarily located via the master
  1144 directory of each theory node (where the .thy file itself resides).
  1145 The global load path is still partially available as legacy feature.
  1146 Minor INCOMPATIBILITY due to subtle change in file lookup: use
  1147 explicit paths, relatively to the theory.
  1148 
  1149 * Special treatment of ML file names has been discontinued.
  1150 Historically, optional extensions .ML or .sml were added on demand --
  1151 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
  1152 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
  1153 
  1154 * Various options that affect pretty printing etc. are now properly
  1155 handled within the context via configuration options, instead of
  1156 unsynchronized references or print modes.  There are both ML Config.T
  1157 entities and Isar declaration attributes to access these.
  1158 
  1159   ML (Config.T)                 Isar (attribute)
  1160 
  1161   eta_contract                  eta_contract
  1162   show_brackets                 show_brackets
  1163   show_sorts                    show_sorts
  1164   show_types                    show_types
  1165   show_question_marks           show_question_marks
  1166   show_consts                   show_consts
  1167   show_abbrevs                  show_abbrevs
  1168 
  1169   Syntax.ast_trace              syntax_ast_trace
  1170   Syntax.ast_stat               syntax_ast_stat
  1171   Syntax.ambiguity_level        syntax_ambiguity_level
  1172 
  1173   Goal_Display.goals_limit      goals_limit
  1174   Goal_Display.show_main_goal   show_main_goal
  1175 
  1176   Method.rule_trace             rule_trace
  1177 
  1178   Thy_Output.display            thy_output_display
  1179   Thy_Output.quotes             thy_output_quotes
  1180   Thy_Output.indent             thy_output_indent
  1181   Thy_Output.source             thy_output_source
  1182   Thy_Output.break              thy_output_break
  1183 
  1184 Note that corresponding "..._default" references in ML may only be
  1185 changed globally at the ROOT session setup, but *not* within a theory.
  1186 The option "show_abbrevs" supersedes the former print mode
  1187 "no_abbrevs" with inverted meaning.
  1188 
  1189 * More systematic naming of some configuration options.
  1190 INCOMPATIBILITY.
  1191 
  1192   trace_simp  ~>  simp_trace
  1193   debug_simp  ~>  simp_debug
  1194 
  1195 * Support for real valued configuration options, using simplistic
  1196 floating-point notation that coincides with the inner syntax for
  1197 float_token.
  1198 
  1199 * Support for real valued preferences (with approximative PGIP type):
  1200 front-ends need to accept "pgint" values in float notation.
  1201 INCOMPATIBILITY.
  1202 
  1203 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
  1204 DejaVu Sans.
  1205 
  1206 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
  1207 
  1208 
  1209 *** Pure ***
  1210 
  1211 * Command 'type_synonym' (with single argument) replaces somewhat
  1212 outdated 'types', which is still available as legacy feature for some
  1213 time.
  1214 
  1215 * Command 'nonterminal' (with 'and' separated list of arguments)
  1216 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
  1217 
  1218 * Command 'notepad' replaces former 'example_proof' for
  1219 experimentation in Isar without any result.  INCOMPATIBILITY.
  1220 
  1221 * Locale interpretation commands 'interpret' and 'sublocale' accept
  1222 lists of equations to map definitions in a locale to appropriate
  1223 entities in the context of the interpretation.  The 'interpretation'
  1224 command already provided this functionality.
  1225 
  1226 * Diagnostic command 'print_dependencies' prints the locale instances
  1227 that would be activated if the specified expression was interpreted in
  1228 the current context.  Variant "print_dependencies!" assumes a context
  1229 without interpretations.
  1230 
  1231 * Diagnostic command 'print_interps' prints interpretations in proofs
  1232 in addition to interpretations in theories.
  1233 
  1234 * Discontinued obsolete 'global' and 'local' commands to manipulate
  1235 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
  1236 Sign.root_path and Sign.local_path may be applied directly where this
  1237 feature is still required for historical reasons.
  1238 
  1239 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
  1240 'definition' instead.
  1241 
  1242 * The "prems" fact, which refers to the accidental collection of
  1243 foundational premises in the context, is now explicitly marked as
  1244 legacy feature and will be discontinued soon.  Consider using "assms"
  1245 of the head statement or reference facts by explicit names.
  1246 
  1247 * Document antiquotations @{class} and @{type} print classes and type
  1248 constructors.
  1249 
  1250 * Document antiquotation @{file} checks file/directory entries within
  1251 the local file system.
  1252 
  1253 
  1254 *** HOL ***
  1255 
  1256 * Coercive subtyping: functions can be declared as coercions and type
  1257 inference will add them as necessary upon input of a term.  Theory
  1258 Complex_Main declares real :: nat => real and real :: int => real as
  1259 coercions. A coercion function f is declared like this:
  1260 
  1261   declare [[coercion f]]
  1262 
  1263 To lift coercions through type constructors (e.g. from nat => real to
  1264 nat list => real list), map functions can be declared, e.g.
  1265 
  1266   declare [[coercion_map map]]
  1267 
  1268 Currently coercion inference is activated only in theories including
  1269 real numbers, i.e. descendants of Complex_Main.  This is controlled by
  1270 the configuration option "coercion_enabled", e.g. it can be enabled in
  1271 other theories like this:
  1272 
  1273   declare [[coercion_enabled]]
  1274 
  1275 * Command 'partial_function' provides basic support for recursive
  1276 function definitions over complete partial orders.  Concrete instances
  1277 are provided for i) the option type, ii) tail recursion on arbitrary
  1278 types, and iii) the heap monad of Imperative_HOL.  See
  1279 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1280 for examples.
  1281 
  1282 * Function package: f.psimps rules are no longer implicitly declared
  1283 as [simp].  INCOMPATIBILITY.
  1284 
  1285 * Datatype package: theorems generated for executable equality (class
  1286 "eq") carry proper names and are treated as default code equations.
  1287 
  1288 * Inductive package: now offers command 'inductive_simps' to
  1289 automatically derive instantiated and simplified equations for
  1290 inductive predicates, similar to 'inductive_cases'.
  1291 
  1292 * Command 'enriched_type' allows to register properties of the
  1293 functorial structure of types.
  1294 
  1295 * Improved infrastructure for term evaluation using code generator
  1296 techniques, in particular static evaluation conversions.
  1297 
  1298 * Code generator: Scala (2.8 or higher) has been added to the target
  1299 languages.
  1300 
  1301 * Code generator: globbing constant expressions "*" and "Theory.*"
  1302 have been replaced by the more idiomatic "_" and "Theory._".
  1303 INCOMPATIBILITY.
  1304 
  1305 * Code generator: export_code without explicit file declaration prints
  1306 to standard output.  INCOMPATIBILITY.
  1307 
  1308 * Code generator: do not print function definitions for case
  1309 combinators any longer.
  1310 
  1311 * Code generator: simplification with rules determined with
  1312 src/Tools/Code/code_simp.ML and method "code_simp".
  1313 
  1314 * Code generator for records: more idiomatic representation of record
  1315 types.  Warning: records are not covered by ancient SML code
  1316 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1317 rep_datatype declaration helps to succeed then:
  1318 
  1319   record 'a foo = ...
  1320   ...
  1321   rep_datatype foo_ext ...
  1322 
  1323 * Records: logical foundation type for records does not carry a
  1324 '_type' suffix any longer (obsolete due to authentic syntax).
  1325 INCOMPATIBILITY.
  1326 
  1327 * Quickcheck now by default uses exhaustive testing instead of random
  1328 testing.  Random testing can be invoked by "quickcheck [random]",
  1329 exhaustive testing by "quickcheck [exhaustive]".
  1330 
  1331 * Quickcheck instantiates polymorphic types with small finite
  1332 datatypes by default. This enables a simple execution mechanism to
  1333 handle quantifiers and function equality over the finite datatypes.
  1334 
  1335 * Quickcheck random generator has been renamed from "code" to
  1336 "random".  INCOMPATIBILITY.
  1337 
  1338 * Quickcheck now has a configurable time limit which is set to 30
  1339 seconds by default. This can be changed by adding [timeout = n] to the
  1340 quickcheck command. The time limit for Auto Quickcheck is still set
  1341 independently.
  1342 
  1343 * Quickcheck in locales considers interpretations of that locale for
  1344 counter example search.
  1345 
  1346 * Sledgehammer:
  1347   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1348     method. See the Sledgehammer manual for details ("isabelle doc
  1349     sledgehammer").
  1350   - Renamed commands:
  1351     sledgehammer atp_info ~> sledgehammer running_provers
  1352     sledgehammer atp_kill ~> sledgehammer kill_provers
  1353     sledgehammer available_atps ~> sledgehammer available_provers
  1354     INCOMPATIBILITY.
  1355   - Renamed options:
  1356     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1357     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1358     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1359     (and "ms" and "min" are no longer supported)
  1360     INCOMPATIBILITY.
  1361 
  1362 * Nitpick:
  1363   - Renamed options:
  1364     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1365     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1366     INCOMPATIBILITY.
  1367   - Added support for partial quotient types.
  1368   - Added local versions of the "Nitpick.register_xxx" functions.
  1369   - Added "whack" option.
  1370   - Allow registration of quotient types as codatatypes.
  1371   - Improved "merge_type_vars" option to merge more types.
  1372   - Removed unsound "fast_descrs" option.
  1373   - Added custom symmetry breaking for datatypes, making it possible to reach
  1374     higher cardinalities.
  1375   - Prevent the expansion of too large definitions.
  1376 
  1377 * Proof methods "metis" and "meson" now have configuration options
  1378 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1379 to diagnose these tools. E.g.
  1380 
  1381     using [[metis_trace = true]]
  1382 
  1383 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1384 manually as command 'solve_direct'.
  1385 
  1386 * The default SMT solver Z3 must be enabled explicitly (due to
  1387 licensing issues) by setting the environment variable
  1388 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1389 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1390 changing the SMT solver is done via the configuration option
  1391 "smt_solver".
  1392 
  1393 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1394 i.e. "remote_cvc3" and "remote_z3".
  1395 
  1396 * Added basic SMT support for datatypes, records, and typedefs using
  1397 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1398 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1399 support for a similar behavior).  Minor INCOMPATIBILITY.
  1400 
  1401 * Changed SMT configuration options:
  1402   - Renamed:
  1403     z3_proofs ~> smt_oracle (with inverted meaning)
  1404     z3_trace_assms ~> smt_trace_used_facts
  1405     INCOMPATIBILITY.
  1406   - Added:
  1407     smt_verbose
  1408     smt_random_seed
  1409     smt_datatypes
  1410     smt_infer_triggers
  1411     smt_monomorph_limit
  1412     cvc3_options
  1413     remote_cvc3_options
  1414     remote_z3_options
  1415     yices_options
  1416 
  1417 * Boogie output files (.b2i files) need to be declared in the theory
  1418 header.
  1419 
  1420 * Simplification procedure "list_to_set_comprehension" rewrites list
  1421 comprehensions applied to List.set to set comprehensions.  Occasional
  1422 INCOMPATIBILITY, may be deactivated like this:
  1423 
  1424   declare [[simproc del: list_to_set_comprehension]]
  1425 
  1426 * Removed old version of primrec package.  INCOMPATIBILITY.
  1427 
  1428 * Removed simplifier congruence rule of "prod_case", as has for long
  1429 been the case with "split".  INCOMPATIBILITY.
  1430 
  1431 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  1432 
  1433 * Removed [split_format ... and ... and ...] version of
  1434 [split_format].  Potential INCOMPATIBILITY.
  1435 
  1436 * Predicate "sorted" now defined inductively, with nice induction
  1437 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  1438 
  1439 * Constant "contents" renamed to "the_elem", to free the generic name
  1440 contents for other uses.  INCOMPATIBILITY.
  1441 
  1442 * Renamed class eq and constant eq (for code generation) to class
  1443 equal and constant equal, plus renaming of related facts and various
  1444 tuning.  INCOMPATIBILITY.
  1445 
  1446 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  1447 
  1448 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  1449 INCOMPATIBILITY.
  1450 
  1451 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  1452 avoid confusion with finite sets.  INCOMPATIBILITY.
  1453 
  1454 * Abandoned locales equiv, congruent and congruent2 for equivalence
  1455 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  1456 for congruent(2)).
  1457 
  1458 * Some previously unqualified names have been qualified:
  1459 
  1460   types
  1461     bool ~> HOL.bool
  1462     nat ~> Nat.nat
  1463 
  1464   constants
  1465     Trueprop ~> HOL.Trueprop
  1466     True ~> HOL.True
  1467     False ~> HOL.False
  1468     op & ~> HOL.conj
  1469     op | ~> HOL.disj
  1470     op --> ~> HOL.implies
  1471     op = ~> HOL.eq
  1472     Not ~> HOL.Not
  1473     The ~> HOL.The
  1474     All ~> HOL.All
  1475     Ex ~> HOL.Ex
  1476     Ex1 ~> HOL.Ex1
  1477     Let ~> HOL.Let
  1478     If ~> HOL.If
  1479     Ball ~> Set.Ball
  1480     Bex ~> Set.Bex
  1481     Suc ~> Nat.Suc
  1482     Pair ~> Product_Type.Pair
  1483     fst ~> Product_Type.fst
  1484     snd ~> Product_Type.snd
  1485     curry ~> Product_Type.curry
  1486     op : ~> Set.member
  1487     Collect ~> Set.Collect
  1488 
  1489 INCOMPATIBILITY.
  1490 
  1491 * More canonical naming convention for some fundamental definitions:
  1492 
  1493     bot_bool_eq ~> bot_bool_def
  1494     top_bool_eq ~> top_bool_def
  1495     inf_bool_eq ~> inf_bool_def
  1496     sup_bool_eq ~> sup_bool_def
  1497     bot_fun_eq  ~> bot_fun_def
  1498     top_fun_eq  ~> top_fun_def
  1499     inf_fun_eq  ~> inf_fun_def
  1500     sup_fun_eq  ~> sup_fun_def
  1501 
  1502 INCOMPATIBILITY.
  1503 
  1504 * More stylized fact names:
  1505 
  1506   expand_fun_eq ~> fun_eq_iff
  1507   expand_set_eq ~> set_eq_iff
  1508   set_ext       ~> set_eqI
  1509   nat_number    ~> eval_nat_numeral
  1510 
  1511 INCOMPATIBILITY.
  1512 
  1513 * Refactoring of code-generation specific operations in theory List:
  1514 
  1515   constants
  1516     null ~> List.null
  1517 
  1518   facts
  1519     mem_iff ~> member_def
  1520     null_empty ~> null_def
  1521 
  1522 INCOMPATIBILITY.  Note that these were not supposed to be used
  1523 regularly unless for striking reasons; their main purpose was code
  1524 generation.
  1525 
  1526 Various operations from the Haskell prelude are used for generating
  1527 Haskell code.
  1528 
  1529 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  1530 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  1531 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  1532 
  1533 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  1534 "*" and "+" respectively.  INCOMPATIBILITY.
  1535 
  1536 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  1537 "Sum_Type.Plus" instead.
  1538 
  1539 * Constant "split" has been merged with constant "prod_case"; names of
  1540 ML functions, facts etc. involving split have been retained so far,
  1541 though.  INCOMPATIBILITY.
  1542 
  1543 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  1544 instead.  INCOMPATIBILITY.
  1545 
  1546 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  1547 INCOMPATIBILITY.
  1548 
  1549 * Former theory Library/Enum is now part of the HOL-Main image.
  1550 INCOMPATIBILITY: all constants of the Enum theory now have to be
  1551 referred to by its qualified name.
  1552 
  1553   enum    ~>  Enum.enum
  1554   nlists  ~>  Enum.nlists
  1555   product ~>  Enum.product
  1556 
  1557 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  1558 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  1559 INCOMPATIBILITY.
  1560 
  1561 * Theory Library/SetsAndFunctions has been split into
  1562 Library/Function_Algebras and Library/Set_Algebras; canonical names
  1563 for instance definitions for functions; various improvements.
  1564 INCOMPATIBILITY.
  1565 
  1566 * Theory Library/Multiset provides stable quicksort implementation of
  1567 sort_key.
  1568 
  1569 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  1570 INCOMPATIBILITY.
  1571 
  1572 * Session Multivariate_Analysis: introduced a type class for euclidean
  1573 space.  Most theorems are now stated in terms of euclidean spaces
  1574 instead of finite cartesian products.
  1575 
  1576   types
  1577     real ^ 'n ~>  'a::real_vector
  1578               ~>  'a::euclidean_space
  1579               ~>  'a::ordered_euclidean_space
  1580         (depends on your needs)
  1581 
  1582   constants
  1583      _ $ _        ~> _ $$ _
  1584      \<chi> x. _  ~> \<chi>\<chi> x. _
  1585      CARD('n)     ~> DIM('a)
  1586 
  1587 Also note that the indices are now natural numbers and not from some
  1588 finite type. Finite cartesian products of euclidean spaces, products
  1589 of euclidean spaces the real and complex numbers are instantiated to
  1590 be euclidean_spaces.  INCOMPATIBILITY.
  1591 
  1592 * Session Probability: introduced pextreal as positive extended real
  1593 numbers.  Use pextreal as value for measures.  Introduce the
  1594 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  1595 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  1596 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  1597 
  1598 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  1599 INCOMPATIBILITY.
  1600 
  1601 * Session SPARK (with image HOL-SPARK) provides commands to load and
  1602 prove verification conditions generated by the SPARK Ada program
  1603 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  1604 
  1605 
  1606 *** HOL-Algebra ***
  1607 
  1608 * Theorems for additive ring operations (locale abelian_monoid and
  1609 descendants) are generated by interpretation from their multiplicative
  1610 counterparts.  Names (in particular theorem names) have the mandatory
  1611 qualifier 'add'.  Previous theorem names are redeclared for
  1612 compatibility.
  1613 
  1614 * Structure "int_ring" is now an abbreviation (previously a
  1615 definition).  This fits more natural with advanced interpretations.
  1616 
  1617 
  1618 *** HOLCF ***
  1619 
  1620 * The domain package now runs in definitional mode by default: The
  1621 former command 'new_domain' is now called 'domain'.  To use the domain
  1622 package in its original axiomatic mode, use 'domain (unsafe)'.
  1623 INCOMPATIBILITY.
  1624 
  1625 * The new class "domain" is now the default sort.  Class "predomain"
  1626 is an unpointed version of "domain". Theories can be updated by
  1627 replacing sort annotations as shown below.  INCOMPATIBILITY.
  1628 
  1629   'a::type ~> 'a::countable
  1630   'a::cpo  ~> 'a::predomain
  1631   'a::pcpo ~> 'a::domain
  1632 
  1633 * The old type class "rep" has been superseded by class "domain".
  1634 Accordingly, users of the definitional package must remove any
  1635 "default_sort rep" declarations.  INCOMPATIBILITY.
  1636 
  1637 * The domain package (definitional mode) now supports unpointed
  1638 predomain argument types, as long as they are marked 'lazy'. (Strict
  1639 arguments must be in class "domain".) For example, the following
  1640 domain definition now works:
  1641 
  1642   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  1643 
  1644 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  1645 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  1646 'a option, and 'a list.  Additionally, it configures fixrec and the
  1647 domain package to work with these types.  For example:
  1648 
  1649   fixrec isInl :: "('a + 'b) u -> tr"
  1650     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  1651 
  1652   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  1653 
  1654 * The "(permissive)" option of fixrec has been replaced with a
  1655 per-equation "(unchecked)" option. See
  1656 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  1657 
  1658 * The "bifinite" class no longer fixes a constant "approx"; the class
  1659 now just asserts that such a function exists.  INCOMPATIBILITY.
  1660 
  1661 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  1662 defines an embedding of type 'a defl into udom by default; instances
  1663 of "bifinite" and "domain" classes are available in
  1664 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  1665 
  1666 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  1667 
  1668 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  1669 
  1670 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  1671 
  1672 * The function "cprod_map" has been renamed to "prod_map".
  1673 INCOMPATIBILITY.
  1674 
  1675 * The monadic bind operator on each powerdomain has new binder syntax
  1676 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  1677 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  1678 
  1679 * The infix syntax for binary union on each powerdomain has changed
  1680 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  1681 syntax.  INCOMPATIBILITY.
  1682 
  1683 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  1684 still supported as an input translation.
  1685 
  1686 * Renamed some theorems (the original names are also still available).
  1687 
  1688   expand_fun_below   ~> fun_below_iff
  1689   below_fun_ext      ~> fun_belowI
  1690   expand_cfun_eq     ~> cfun_eq_iff
  1691   ext_cfun           ~> cfun_eqI
  1692   expand_cfun_below  ~> cfun_below_iff
  1693   below_cfun_ext     ~> cfun_belowI
  1694   cont2cont_Rep_CFun ~> cont2cont_APP
  1695 
  1696 * The Abs and Rep functions for various types have changed names.
  1697 Related theorem names have also changed to match. INCOMPATIBILITY.
  1698 
  1699   Rep_CFun  ~> Rep_cfun
  1700   Abs_CFun  ~> Abs_cfun
  1701   Rep_Sprod ~> Rep_sprod
  1702   Abs_Sprod ~> Abs_sprod
  1703   Rep_Ssum  ~> Rep_ssum
  1704   Abs_Ssum  ~> Abs_ssum
  1705 
  1706 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  1707 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  1708 
  1709 * Various changes to bisimulation/coinduction with domain package:
  1710 
  1711   - Definitions of "bisim" constants no longer mention definedness.
  1712   - With mutual recursion, "bisim" predicate is now curried.
  1713   - With mutual recursion, each type gets a separate coind theorem.
  1714   - Variable names in bisim_def and coinduct rules have changed.
  1715 
  1716 INCOMPATIBILITY.
  1717 
  1718 * Case combinators generated by the domain package for type "foo" are
  1719 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  1720 
  1721 * Several theorems have been renamed to more accurately reflect the
  1722 names of constants and types involved.  INCOMPATIBILITY.
  1723 
  1724   thelub_const    ~> lub_const
  1725   lub_const       ~> is_lub_const
  1726   thelubI         ~> lub_eqI
  1727   is_lub_lub      ~> is_lubD2
  1728   lubI            ~> is_lub_lub
  1729   unique_lub      ~> is_lub_unique
  1730   is_ub_lub       ~> is_lub_rangeD1
  1731   lub_bin_chain   ~> is_lub_bin_chain
  1732   lub_fun         ~> is_lub_fun
  1733   thelub_fun      ~> lub_fun
  1734   thelub_cfun     ~> lub_cfun
  1735   thelub_Pair     ~> lub_Pair
  1736   lub_cprod       ~> is_lub_prod
  1737   thelub_cprod    ~> lub_prod
  1738   minimal_cprod   ~> minimal_prod
  1739   inst_cprod_pcpo ~> inst_prod_pcpo
  1740   UU_I            ~> bottomI
  1741   compact_UU      ~> compact_bottom
  1742   deflation_UU    ~> deflation_bottom
  1743   finite_deflation_UU ~> finite_deflation_bottom
  1744 
  1745 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  1746 
  1747   sq_ord_less_eq_trans ~> below_eq_trans
  1748   sq_ord_eq_less_trans ~> eq_below_trans
  1749   refl_less            ~> below_refl
  1750   trans_less           ~> below_trans
  1751   antisym_less         ~> below_antisym
  1752   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  1753   box_less             ~> box_below
  1754   rev_trans_less       ~> rev_below_trans
  1755   not_less2not_eq      ~> not_below2not_eq
  1756   less_UU_iff          ~> below_UU_iff
  1757   flat_less_iff        ~> flat_below_iff
  1758   adm_less             ~> adm_below
  1759   adm_not_less         ~> adm_not_below
  1760   adm_compact_not_less ~> adm_compact_not_below
  1761   less_fun_def         ~> below_fun_def
  1762   expand_fun_less      ~> fun_below_iff
  1763   less_fun_ext         ~> fun_belowI
  1764   less_discr_def       ~> below_discr_def
  1765   discr_less_eq        ~> discr_below_eq
  1766   less_unit_def        ~> below_unit_def
  1767   less_cprod_def       ~> below_prod_def
  1768   prod_lessI           ~> prod_belowI
  1769   Pair_less_iff        ~> Pair_below_iff
  1770   fst_less_iff         ~> fst_below_iff
  1771   snd_less_iff         ~> snd_below_iff
  1772   expand_cfun_less     ~> cfun_below_iff
  1773   less_cfun_ext        ~> cfun_belowI
  1774   injection_less       ~> injection_below
  1775   less_up_def          ~> below_up_def
  1776   not_Iup_less         ~> not_Iup_below
  1777   Iup_less             ~> Iup_below
  1778   up_less              ~> up_below
  1779   Def_inject_less_eq   ~> Def_below_Def
  1780   Def_less_is_eq       ~> Def_below_iff
  1781   spair_less_iff       ~> spair_below_iff
  1782   less_sprod           ~> below_sprod
  1783   spair_less           ~> spair_below
  1784   sfst_less_iff        ~> sfst_below_iff
  1785   ssnd_less_iff        ~> ssnd_below_iff
  1786   fix_least_less       ~> fix_least_below
  1787   dist_less_one        ~> dist_below_one
  1788   less_ONE             ~> below_ONE
  1789   ONE_less_iff         ~> ONE_below_iff
  1790   less_sinlD           ~> below_sinlD
  1791   less_sinrD           ~> below_sinrD
  1792 
  1793 
  1794 *** FOL and ZF ***
  1795 
  1796 * All constant names are now qualified internally and use proper
  1797 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  1798 
  1799 *** ZF ***
  1800 
  1801 * Greater support for structured proofs involving induction or case analysis.
  1802 
  1803 * Much greater use of special symbols.
  1804 
  1805 * Removal of many ML theorem bindings. INCOMPATIBILITY.
  1806 
  1807 *** ML ***
  1808 
  1809 * Antiquotation @{assert} inlines a function bool -> unit that raises
  1810 Fail if the argument is false.  Due to inlining the source position of
  1811 failed assertions is included in the error output.
  1812 
  1813 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  1814 text is in practice always evaluated with a stable theory checkpoint.
  1815 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  1816 
  1817 * Antiquotation @{theory A} refers to theory A from the ancestry of
  1818 the current context, not any accidental theory loader state as before.
  1819 Potential INCOMPATIBILITY, subtle change in semantics.
  1820 
  1821 * Syntax.pretty_priority (default 0) configures the required priority
  1822 of pretty-printed output and thus affects insertion of parentheses.
  1823 
  1824 * Syntax.default_root (default "any") configures the inner syntax
  1825 category (nonterminal symbol) for parsing of terms.
  1826 
  1827 * Former exception Library.UnequalLengths now coincides with
  1828 ListPair.UnequalLengths.
  1829 
  1830 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1831 main functionality is provided by structure Simplifier.
  1832 
  1833 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1834 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1835 almost all situations.
  1836 
  1837 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1838 See implementation manual for further details on exceptions in
  1839 Isabelle/ML.
  1840 
  1841 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1842 meaning.
  1843 
  1844 * Renamed structure PureThy to Pure_Thy and moved most of its
  1845 operations to structure Global_Theory, to emphasize that this is
  1846 rarely-used global-only stuff.
  1847 
  1848 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1849 instead (or tracing for high-volume output).
  1850 
  1851 * Configuration option show_question_marks only affects regular pretty
  1852 printing of types and terms, not raw Term.string_of_vname.
  1853 
  1854 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1855 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1856 @{thms} for most purposes.
  1857 
  1858 * ML structure Unsynchronized is never opened, not even in Isar
  1859 interaction mode as before.  Old Unsynchronized.set etc. have been
  1860 discontinued -- use plain := instead.  This should be *rare* anyway,
  1861 since modern tools always work via official context data, notably
  1862 configuration options.
  1863 
  1864 * Parallel and asynchronous execution requires special care concerning
  1865 interrupts.  Structure Exn provides some convenience functions that
  1866 avoid working directly with raw Interrupt.  User code must not absorb
  1867 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1868 followed by re-raising of the original exception.  Another common
  1869 source of mistakes are "handle _" patterns, which make the meaning of
  1870 the program subject to physical effects of the environment.
  1871 
  1872 
  1873 
  1874 New in Isabelle2009-2 (June 2010)
  1875 ---------------------------------
  1876 
  1877 *** General ***
  1878 
  1879 * Authentic syntax for *all* logical entities (type classes, type
  1880 constructors, term constants): provides simple and robust
  1881 correspondence between formal entities and concrete syntax.  Within
  1882 the parse tree / AST representations, "constants" are decorated by
  1883 their category (class, type, const) and spelled out explicitly with
  1884 their full internal name.
  1885 
  1886 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1887 and translations (translation rules and translation functions in ML).
  1888 Some hints on upgrading:
  1889 
  1890   - Many existing uses of 'syntax' and 'translations' can be replaced
  1891     by more modern 'type_notation', 'notation' and 'abbreviation',
  1892     which are independent of this issue.
  1893 
  1894   - 'translations' require markup within the AST; the term syntax
  1895     provides the following special forms:
  1896 
  1897       CONST c   -- produces syntax version of constant c from context
  1898       XCONST c  -- literally c, checked as constant from context
  1899       c         -- literally c, if declared by 'syntax'
  1900 
  1901     Plain identifiers are treated as AST variables -- occasionally the
  1902     system indicates accidental variables via the error "rhs contains
  1903     extra variables".
  1904 
  1905     Type classes and type constructors are marked according to their
  1906     concrete syntax.  Some old translations rules need to be written
  1907     for the "type" category, using type constructor application
  1908     instead of pseudo-term application of the default category
  1909     "logic".
  1910 
  1911   - 'parse_translation' etc. in ML may use the following
  1912     antiquotations:
  1913 
  1914       @{class_syntax c}   -- type class c within parse tree / AST
  1915       @{term_syntax c}    -- type constructor c within parse tree / AST
  1916       @{const_syntax c}   -- ML version of "CONST c" above
  1917       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1918 
  1919   - Literal types within 'typed_print_translations', i.e. those *not*
  1920     represented as pseudo-terms are represented verbatim.  Use @{class
  1921     c} or @{type_name c} here instead of the above syntax
  1922     antiquotations.
  1923 
  1924 Note that old non-authentic syntax was based on unqualified base
  1925 names, so all of the above "constant" names would coincide.  Recall
  1926 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1927 diagnose syntax problems.
  1928 
  1929 * Type constructors admit general mixfix syntax, not just infix.
  1930 
  1931 * Concrete syntax may be attached to local entities without a proof
  1932 body, too.  This works via regular mixfix annotations for 'fix',
  1933 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1934 similar to the 'notation' command in theory specifications.
  1935 
  1936 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1937 need to specify constant name and syntax separately.  Internal ML
  1938 datatype constructors have been renamed from InfixName to Infix etc.
  1939 Minor INCOMPATIBILITY.
  1940 
  1941 * Schematic theorem statements need to be explicitly markup as such,
  1942 via commands 'schematic_lemma', 'schematic_theorem',
  1943 'schematic_corollary'.  Thus the relevance of the proof is made
  1944 syntactically clear, which impacts performance in a parallel or
  1945 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1946 
  1947 * Use of cumulative prems via "!" in some proof methods has been
  1948 discontinued (old legacy feature).
  1949 
  1950 * References 'trace_simp' and 'debug_simp' have been replaced by
  1951 configuration options stored in the context. Enabling tracing (the
  1952 case of debugging is similar) in proofs works via
  1953 
  1954   using [[trace_simp = true]]
  1955 
  1956 Tracing is then active for all invocations of the simplifier in
  1957 subsequent goal refinement steps. Tracing may also still be enabled or
  1958 disabled via the ProofGeneral settings menu.
  1959 
  1960 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1961 'hide_fact' replace the former 'hide' KIND command.  Minor
  1962 INCOMPATIBILITY.
  1963 
  1964 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1965 more efficient than combinations with -q1 or -q2.
  1966 
  1967 
  1968 *** Pure ***
  1969 
  1970 * Proofterms record type-class reasoning explicitly, using the
  1971 "unconstrain" operation internally.  This eliminates all sort
  1972 constraints from a theorem and proof, introducing explicit
  1973 OFCLASS-premises.  On the proof term level, this operation is
  1974 automatically applied at theorem boundaries, such that closed proofs
  1975 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1976 inspect proof terms.
  1977 
  1978 * Local theory specifications may depend on extra type variables that
  1979 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1980 are added internally.  For example:
  1981 
  1982   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1983 
  1984 * Predicates of locales introduced by classes carry a mandatory
  1985 "class" prefix.  INCOMPATIBILITY.
  1986 
  1987 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1988 
  1989 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1990 'class' instead.
  1991 
  1992 * Command 'code_reflect' allows to incorporate generated ML code into
  1993 runtime environment; replaces immature code_datatype antiquotation.
  1994 INCOMPATIBILITY.
  1995 
  1996 * Code generator: simple concept for abstract datatypes obeying
  1997 invariants.
  1998 
  1999 * Code generator: details of internal data cache have no impact on the
  2000 user space functionality any longer.
  2001 
  2002 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  2003 subgoals.  This is more appropriate for interpretations with 'where'.
  2004 INCOMPATIBILITY.
  2005 
  2006 * Command 'example_proof' opens an empty proof body.  This allows to
  2007 experiment with Isar, without producing any persistent result.
  2008 
  2009 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  2010 within a local theory context, with explicit checking of the
  2011 constructors involved (in contrast to the raw 'syntax' versions).
  2012 
  2013 * Commands 'types' and 'typedecl' now work within a local theory
  2014 context -- without introducing dependencies on parameters or
  2015 assumptions, which is not possible in Isabelle/Pure.
  2016 
  2017 * Command 'defaultsort' has been renamed to 'default_sort', it works
  2018 within a local theory context.  Minor INCOMPATIBILITY.
  2019 
  2020 
  2021 *** HOL ***
  2022 
  2023 * Command 'typedef' now works within a local theory context -- without
  2024 introducing dependencies on parameters or assumptions, which is not
  2025 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  2026 contain multiple interpretations of local typedefs (with different
  2027 non-emptiness proofs), even in a global theory context.
  2028 
  2029 * New package for quotient types.  Commands 'quotient_type' and
  2030 'quotient_definition' may be used for defining types and constants by
  2031 quotient constructions.  An example is the type of integers created by
  2032 quotienting pairs of natural numbers:
  2033 
  2034   fun
  2035     intrel :: "(nat * nat) => (nat * nat) => bool"
  2036   where
  2037     "intrel (x, y) (u, v) = (x + v = u + y)"
  2038 
  2039   quotient_type int = "nat * nat" / intrel
  2040     by (auto simp add: equivp_def expand_fun_eq)
  2041 
  2042   quotient_definition
  2043     "0::int" is "(0::nat, 0::nat)"
  2044 
  2045 The method "lifting" can be used to lift of theorems from the
  2046 underlying "raw" type to the quotient type.  The example
  2047 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  2048 construction and provides a reasoning infrastructure for finite sets.
  2049 
  2050 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  2051 clash with new theory Quotient in Main HOL.
  2052 
  2053 * Moved the SMT binding into the main HOL session, eliminating
  2054 separate HOL-SMT session.
  2055 
  2056 * List membership infix mem operation is only an input abbreviation.
  2057 INCOMPATIBILITY.
  2058 
  2059 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  2060 for future developements; former Library/Word.thy is still present in
  2061 the AFP entry RSAPPS.
  2062 
  2063 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  2064 longer shadowed.  INCOMPATIBILITY.
  2065 
  2066 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  2067 INCOMPATIBILITY.
  2068 
  2069 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  2070 INCOMPATIBILITY.
  2071 
  2072 * Dropped normalizing_semiring etc; use the facts in semiring classes
  2073 instead.  INCOMPATIBILITY.
  2074 
  2075 * Dropped several real-specific versions of lemmas about floor and
  2076 ceiling; use the generic lemmas from theory "Archimedean_Field"
  2077 instead.  INCOMPATIBILITY.
  2078 
  2079   floor_number_of_eq         ~> floor_number_of
  2080   le_floor_eq_number_of      ~> number_of_le_floor
  2081   le_floor_eq_zero           ~> zero_le_floor
  2082   le_floor_eq_one            ~> one_le_floor
  2083   floor_less_eq_number_of    ~> floor_less_number_of
  2084   floor_less_eq_zero         ~> floor_less_zero
  2085   floor_less_eq_one          ~> floor_less_one
  2086   less_floor_eq_number_of    ~> number_of_less_floor
  2087   less_floor_eq_zero         ~> zero_less_floor
  2088   less_floor_eq_one          ~> one_less_floor
  2089   floor_le_eq_number_of      ~> floor_le_number_of
  2090   floor_le_eq_zero           ~> floor_le_zero
  2091   floor_le_eq_one            ~> floor_le_one
  2092   floor_subtract_number_of   ~> floor_diff_number_of
  2093   floor_subtract_one         ~> floor_diff_one
  2094   ceiling_number_of_eq       ~> ceiling_number_of
  2095   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  2096   ceiling_le_zero_eq         ~> ceiling_le_zero
  2097   ceiling_le_eq_one          ~> ceiling_le_one
  2098   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  2099   less_ceiling_eq_zero       ~> zero_less_ceiling
  2100   less_ceiling_eq_one        ~> one_less_ceiling
  2101   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  2102   ceiling_less_eq_zero       ~> ceiling_less_zero
  2103   ceiling_less_eq_one        ~> ceiling_less_one
  2104   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  2105   le_ceiling_eq_zero         ~> zero_le_ceiling
  2106   le_ceiling_eq_one          ~> one_le_ceiling
  2107   ceiling_subtract_number_of ~> ceiling_diff_number_of
  2108   ceiling_subtract_one       ~> ceiling_diff_one
  2109 
  2110 * Theory "Finite_Set": various folding_XXX locales facilitate the
  2111 application of the various fold combinators on finite sets.
  2112 
  2113 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  2114 provides abstract red-black tree type which is backed by "RBT_Impl" as
  2115 implementation.  INCOMPATIBILTY.
  2116 
  2117 * Theory Library/Coinductive_List has been removed -- superseded by
  2118 AFP/thys/Coinductive.
  2119 
  2120 * Theory PReal, including the type "preal" and related operations, has
  2121 been removed.  INCOMPATIBILITY.
  2122 
  2123 * Real: new development using Cauchy Sequences.
  2124 
  2125 * Split off theory "Big_Operators" containing setsum, setprod,
  2126 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  2127 
  2128 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  2129 "Int" etc.  INCOMPATIBILITY.
  2130 
  2131 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  2132 
  2133 * New set of rules "ac_simps" provides combined assoc / commute
  2134 rewrites for all interpretations of the appropriate generic locales.
  2135 
  2136 * Renamed theory "OrderedGroup" to "Groups" and split theory
  2137 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  2138 appropriate and more consistent names suitable for name prefixes
  2139 within the HOL theories.  INCOMPATIBILITY.
  2140 
  2141 * Some generic constants have been put to appropriate theories:
  2142   - less_eq, less: Orderings
  2143   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  2144   - inverse, divide: Rings
  2145 INCOMPATIBILITY.
  2146 
  2147 * More consistent naming of type classes involving orderings (and
  2148 lattices):
  2149 
  2150     lower_semilattice                   ~> semilattice_inf
  2151     upper_semilattice                   ~> semilattice_sup
  2152 
  2153     dense_linear_order                  ~> dense_linorder
  2154 
  2155     pordered_ab_group_add               ~> ordered_ab_group_add
  2156     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  2157     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  2158     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  2159     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  2160     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  2161     pordered_cancel_semiring            ~> ordered_cancel_semiring
  2162     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  2163     pordered_comm_ring                  ~> ordered_comm_ring
  2164     pordered_comm_semiring              ~> ordered_comm_semiring
  2165     pordered_ring                       ~> ordered_ring
  2166     pordered_ring_abs                   ~> ordered_ring_abs
  2167     pordered_semiring                   ~> ordered_semiring
  2168 
  2169     ordered_ab_group_add                ~> linordered_ab_group_add
  2170     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  2171     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  2172     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  2173     ordered_field                       ~> linordered_field
  2174     ordered_field_no_lb                 ~> linordered_field_no_lb
  2175     ordered_field_no_ub                 ~> linordered_field_no_ub
  2176     ordered_field_dense_linear_order    ~> dense_linordered_field
  2177     ordered_idom                        ~> linordered_idom
  2178     ordered_ring                        ~> linordered_ring
  2179     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  2180     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  2181     ordered_ring_strict                 ~> linordered_ring_strict
  2182     ordered_semidom                     ~> linordered_semidom
  2183     ordered_semiring                    ~> linordered_semiring
  2184     ordered_semiring_1                  ~> linordered_semiring_1
  2185     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  2186     ordered_semiring_strict             ~> linordered_semiring_strict
  2187 
  2188   The following slightly odd type classes have been moved to a
  2189   separate theory Library/Lattice_Algebras:
  2190 
  2191     lordered_ab_group_add               ~> lattice_ab_group_add
  2192     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  2193     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  2194     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  2195     lordered_ring                       ~> lattice_ring
  2196 
  2197 INCOMPATIBILITY.
  2198 
  2199 * Refined field classes:
  2200   - classes division_ring_inverse_zero, field_inverse_zero,
  2201     linordered_field_inverse_zero include rule inverse 0 = 0 --
  2202     subsumes former division_by_zero class;
  2203   - numerous lemmas have been ported from field to division_ring.
  2204 INCOMPATIBILITY.
  2205 
  2206 * Refined algebra theorem collections:
  2207   - dropped theorem group group_simps, use algebra_simps instead;
  2208   - dropped theorem group ring_simps, use field_simps instead;
  2209   - proper theorem collection field_simps subsumes former theorem
  2210     groups field_eq_simps and field_simps;
  2211   - dropped lemma eq_minus_self_iff which is a duplicate for
  2212     equal_neg_zero.
  2213 INCOMPATIBILITY.
  2214 
  2215 * Theory Finite_Set and List: some lemmas have been generalized from
  2216 sets to lattices:
  2217 
  2218   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  2219   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  2220   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  2221   union_Union_fold_union        ~> sup_Sup_fold_sup
  2222   Inter_fold_inter              ~> Inf_fold_inf
  2223   Union_fold_union              ~> Sup_fold_sup
  2224   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  2225   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  2226   INTER_fold_inter              ~> INFI_fold_inf
  2227   UNION_fold_union              ~> SUPR_fold_sup
  2228 
  2229 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  2230 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  2231 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  2232 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  2233 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  2234 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  2235 
  2236 * Reorganized theory Multiset: swapped notation of pointwise and
  2237 multiset order:
  2238 
  2239   - pointwise ordering is instance of class order with standard syntax
  2240     <= and <;
  2241   - multiset ordering has syntax <=# and <#; partial order properties
  2242     are provided by means of interpretation with prefix
  2243     multiset_order;
  2244   - less duplication, less historical organization of sections,
  2245     conversion from associations lists to multisets, rudimentary code
  2246     generation;
  2247   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  2248     if needed.
  2249 
  2250 Renamed:
  2251 
  2252   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  2253   multi_count_ext  ~>  multiset_ext
  2254   diff_union_inverse2  ~>  diff_union_cancelR
  2255 
  2256 INCOMPATIBILITY.
  2257 
  2258 * Theory Permutation: replaced local "remove" by List.remove1.
  2259 
  2260 * Code generation: ML and OCaml code is decorated with signatures.
  2261 
  2262 * Theory List: added transpose.
  2263 
  2264 * Library/Nat_Bijection.thy is a collection of bijective functions
  2265 between nat and other types, which supersedes the older libraries
  2266 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  2267 
  2268   Constants:
  2269   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  2270   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  2271   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  2272   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  2273   Countable.pair_encode           ~> prod_encode
  2274   NatIso.prod2nat                 ~> prod_encode
  2275   NatIso.nat2prod                 ~> prod_decode
  2276   NatIso.sum2nat                  ~> sum_encode
  2277   NatIso.nat2sum                  ~> sum_decode
  2278   NatIso.list2nat                 ~> list_encode
  2279   NatIso.nat2list                 ~> list_decode
  2280   NatIso.set2nat                  ~> set_encode
  2281   NatIso.nat2set                  ~> set_decode
  2282 
  2283   Lemmas:
  2284   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2285   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2286   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2287   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2288   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2289   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2290   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2291   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2292   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2293   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2294   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2295   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2296   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2297 
  2298 * Sledgehammer:
  2299   - Renamed ATP commands:
  2300     atp_info     ~> sledgehammer running_atps
  2301     atp_kill     ~> sledgehammer kill_atps
  2302     atp_messages ~> sledgehammer messages
  2303     atp_minimize ~> sledgehammer minimize
  2304     print_atps   ~> sledgehammer available_atps
  2305     INCOMPATIBILITY.
  2306   - Added user's manual ("isabelle doc sledgehammer").
  2307   - Added option syntax and "sledgehammer_params" to customize
  2308     Sledgehammer's behavior.  See the manual for details.
  2309   - Modified the Isar proof reconstruction code so that it produces
  2310     direct proofs rather than proofs by contradiction.  (This feature
  2311     is still experimental.)
  2312   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2313     full-typed mode.
  2314   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2315 
  2316 * Nitpick:
  2317   - Added and implemented "binary_ints" and "bits" options.
  2318   - Added "std" option and implemented support for nonstandard models.
  2319   - Added and implemented "finitize" option to improve the precision
  2320     of infinite datatypes based on a monotonicity analysis.
  2321   - Added support for quotient types.
  2322   - Added support for "specification" and "ax_specification"
  2323     constructs.
  2324   - Added support for local definitions (for "function" and
  2325     "termination" proofs).
  2326   - Added support for term postprocessors.
  2327   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2328   - Improved efficiency of "destroy_constrs" optimization.
  2329   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2330     record getters.
  2331   - Fixed soundness bug related to higher-order constructors.
  2332   - Fixed soundness bug when "full_descrs" is enabled.
  2333   - Improved precision of set constructs.
  2334   - Added "atoms" option.
  2335   - Added cache to speed up repeated Kodkod invocations on the same
  2336     problems.
  2337   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2338     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2339     "SAT4J_Light".  INCOMPATIBILITY.
  2340   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2341     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2342   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2343 
  2344 * Method "induct" now takes instantiations of the form t, where t is not
  2345   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2346   If this is not intended, t has to be enclosed in parentheses.
  2347   By default, the equalities generated by definitional instantiations
  2348   are pre-simplified, which may cause parameters of inductive cases
  2349   to disappear, or may even delete some of the inductive cases.
  2350   Use "induct (no_simp)" instead of "induct" to restore the old
  2351   behaviour. The (no_simp) option is also understood by the "cases"
  2352   and "nominal_induct" methods, which now perform pre-simplification, too.
  2353   INCOMPATIBILITY.
  2354 
  2355 
  2356 *** HOLCF ***
  2357 
  2358 * Variable names in lemmas generated by the domain package have
  2359 changed; the naming scheme is now consistent with the HOL datatype
  2360 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2361 
  2362 * The domain package no longer defines the function "foo_copy" for
  2363 recursive domain "foo".  The reach lemma is now stated directly in
  2364 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2365 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2366 
  2367 * Most definedness lemmas generated by the domain package (previously
  2368 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2369 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2370 Proofs that used definedness lemmas as intro rules may break,
  2371 potential INCOMPATIBILITY.
  2372 
  2373 * Induction and casedist rules generated by the domain package now
  2374 declare proper case_names (one called "bottom", and one named for each
  2375 constructor).  INCOMPATIBILITY.
  2376 
  2377 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2378 rules are generated for each domain, INCOMPATIBILITY.
  2379 
  2380   foo_bar.reach       ~> foo.reach  bar.reach
  2381   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2382 
  2383 * Some lemmas generated by the domain package have been renamed for
  2384 consistency with the datatype package, INCOMPATIBILITY.
  2385 
  2386   foo.ind        ~> foo.induct
  2387   foo.finite_ind ~> foo.finite_induct
  2388   foo.coind      ~> foo.coinduct
  2389   foo.casedist   ~> foo.exhaust
  2390   foo.exhaust    ~> foo.nchotomy
  2391 
  2392 * For consistency with other definition packages, the fixrec package
  2393 now generates qualified theorem names, INCOMPATIBILITY.
  2394 
  2395   foo_simps  ~> foo.simps
  2396   foo_unfold ~> foo.unfold
  2397   foo_induct ~> foo.induct
  2398 
  2399 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2400 method and internal fixrec proofs now use the default simpset instead.
  2401 INCOMPATIBILITY.
  2402 
  2403 * The "contlub" predicate has been removed.  Proof scripts should use
  2404 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2405 
  2406 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2407 
  2408 * The constants cpair, cfst, and csnd have been removed in favor of
  2409 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2410 
  2411 
  2412 *** ML ***
  2413 
  2414 * Antiquotations for basic formal entities:
  2415 
  2416     @{class NAME}         -- type class
  2417     @{class_syntax NAME}  -- syntax representation of the above
  2418 
  2419     @{type_name NAME}     -- logical type
  2420     @{type_abbrev NAME}   -- type abbreviation
  2421     @{nonterminal NAME}   -- type of concrete syntactic category
  2422     @{type_syntax NAME}   -- syntax representation of any of the above
  2423 
  2424     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2425     @{const_abbrev NAME}  -- abbreviated constant
  2426     @{const_syntax NAME}  -- syntax representation of any of the above
  2427 
  2428 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  2429 syntax constant (cf. 'syntax' command).
  2430 
  2431 * Antiquotation @{make_string} inlines a function to print arbitrary
  2432 values similar to the ML toplevel.  The result is compiler dependent
  2433 and may fall back on "?" in certain situations.
  2434 
  2435 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  2436 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  2437 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  2438 not work with the asynchronous Isar document model.
  2439 
  2440 * Configuration options now admit dynamic default values, depending on
  2441 the context or even global references.
  2442 
  2443 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  2444 uses an efficient external library if available (for Poly/ML).
  2445 
  2446 * Renamed some important ML structures, while keeping the old names
  2447 for some time as aliases within the structure Legacy:
  2448 
  2449   OuterKeyword  ~>  Keyword
  2450   OuterLex      ~>  Token
  2451   OuterParse    ~>  Parse
  2452   OuterSyntax   ~>  Outer_Syntax
  2453   PrintMode     ~>  Print_Mode
  2454   SpecParse     ~>  Parse_Spec
  2455   ThyInfo       ~>  Thy_Info
  2456   ThyLoad       ~>  Thy_Load
  2457   ThyOutput     ~>  Thy_Output
  2458   TypeInfer     ~>  Type_Infer
  2459 
  2460 Note that "open Legacy" simplifies porting of sources, but forgetting
  2461 to remove it again will complicate porting again in the future.
  2462 
  2463 * Most operations that refer to a global context are named
  2464 accordingly, e.g. Simplifier.global_context or
  2465 ProofContext.init_global.  There are some situations where a global
  2466 context actually works, but under normal circumstances one needs to
  2467 pass the proper local context through the code!
  2468 
  2469 * Discontinued old TheoryDataFun with its copy/init operation -- data
  2470 needs to be pure.  Functor Theory_Data_PP retains the traditional
  2471 Pretty.pp argument to merge, which is absent in the standard
  2472 Theory_Data version.
  2473 
  2474 * Sorts.certify_sort and derived "cert" operations for types and terms
  2475 no longer minimize sorts.  Thus certification at the boundary of the
  2476 inference kernel becomes invariant under addition of class relations,
  2477 which is an important monotonicity principle.  Sorts are now minimized
  2478 in the syntax layer only, at the boundary between the end-user and the
  2479 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  2480 explicitly in rare situations.
  2481 
  2482 * Renamed old-style Drule.standard to Drule.export_without_context, to
  2483 emphasize that this is in no way a standard operation.
  2484 INCOMPATIBILITY.
  2485 
  2486 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  2487 usual for resolution.  Rare INCOMPATIBILITY.
  2488 
  2489 * Renamed varify/unvarify operations to varify_global/unvarify_global
  2490 to emphasize that these only work in a global situation (which is
  2491 quite rare).
  2492 
  2493 * Curried take and drop in library.ML; negative length is interpreted
  2494 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  2495 
  2496 * Proof terms: type substitutions on proof constants now use canonical
  2497 order of type variables.  INCOMPATIBILITY for tools working with proof
  2498 terms.
  2499 
  2500 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  2501 may no longer carry premises.  User-level specifications are
  2502 transformed accordingly by Thm.add_axiom/add_def.
  2503 
  2504 
  2505 *** System ***
  2506 
  2507 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  2508 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  2509 proof terms are enabled unconditionally in the new HOL-Proofs image.
  2510 
  2511 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  2512 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  2513 respectively.
  2514 
  2515 * Old lib/scripts/polyml-platform is superseded by the
  2516 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  2517 variant, even on a 64 bit machine.  The following example setting
  2518 prefers 64 bit if available:
  2519 
  2520   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  2521 
  2522 * The preliminary Isabelle/jEdit application demonstrates the emerging
  2523 Isabelle/Scala layer for advanced prover interaction and integration.
  2524 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  2525 component.
  2526 
  2527 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  2528 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  2529 similar to the default assignment of the document preparation system
  2530 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  2531 provides some operations for direct access to the font without asking
  2532 the user for manual installation.
  2533 
  2534 
  2535 
  2536 New in Isabelle2009-1 (December 2009)
  2537 -------------------------------------
  2538 
  2539 *** General ***
  2540 
  2541 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  2542 one backslash should be used, even in ML sources.
  2543 
  2544 
  2545 *** Pure ***
  2546 
  2547 * Locale interpretation propagates mixins along the locale hierarchy.
  2548 The currently only available mixins are the equations used to map
  2549 local definitions to terms of the target domain of an interpretation.
  2550 
  2551 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  2552 loc" to print all interpretations of locale "loc" in the theory.
  2553 Interpretations in proofs are not shown.
  2554 
  2555 * Thoroughly revised locales tutorial.  New section on conditional
  2556 interpretation.
  2557 
  2558 * On instantiation of classes, remaining undefined class parameters
  2559 are formally declared.  INCOMPATIBILITY.
  2560 
  2561 
  2562 *** Document preparation ***
  2563 
  2564 * New generalized style concept for printing terms: @{foo (style) ...}
  2565 instead of @{foo_style style ...}  (old form is still retained for
  2566 backward compatibility).  Styles can be also applied for
  2567 antiquotations prop, term_type and typeof.
  2568 
  2569 
  2570 *** HOL ***
  2571 
  2572 * New proof method "smt" for a combination of first-order logic with
  2573 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  2574 fixed-size bitvectors; there is also basic support for higher-order
  2575 features (esp. lambda abstractions).  It is an incomplete decision
  2576 procedure based on external SMT solvers using the oracle mechanism;
  2577 for the SMT solver Z3, this method is proof-producing.  Certificates
  2578 are provided to avoid calling the external solvers solely for
  2579 re-checking proofs.  Due to a remote SMT service there is no need for
  2580 installing SMT solvers locally.  See src/HOL/SMT.
  2581 
  2582 * New commands to load and prove verification conditions generated by
  2583 the Boogie program verifier or derived systems (e.g. the Verifying C
  2584 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  2585 
  2586 * New counterexample generator tool 'nitpick' based on the Kodkod
  2587 relational model finder.  See src/HOL/Tools/Nitpick and
  2588 src/HOL/Nitpick_Examples.
  2589 
  2590 * New commands 'code_pred' and 'values' to invoke the predicate
  2591 compiler and to enumerate values of inductive predicates.
  2592 
  2593 * A tabled implementation of the reflexive transitive closure.
  2594 
  2595 * New implementation of quickcheck uses generic code generator;
  2596 default generators are provided for all suitable HOL types, records
  2597 and datatypes.  Old quickcheck can be re-activated importing theory
  2598 Library/SML_Quickcheck.
  2599 
  2600 * New testing tool Mirabelle for automated proof tools.  Applies
  2601 several tools and tactics like sledgehammer, metis, or quickcheck, to
  2602 every proof step in a theory.  To be used in batch mode via the
  2603 "mirabelle" utility.
  2604 
  2605 * New proof method "sos" (sum of squares) for nonlinear real
  2606 arithmetic (originally due to John Harison). It requires theory
  2607 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  2608 works well in practice on quantifier-free real arithmetic with +, -,
  2609 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  2610 inequalities between polynomials.  It makes use of external
  2611 semidefinite programming solvers.  Method "sos" generates a
  2612 certificate that can be pasted into the proof thus avoiding the need
  2613 to call an external tool every time the proof is checked.  See
  2614 src/HOL/Library/Sum_Of_Squares.
  2615 
  2616 * New method "linarith" invokes existing linear arithmetic decision
  2617 procedure only.
  2618 
  2619 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  2620 
  2621 * New Sledgehammer option "Full Types" in Proof General settings menu.
  2622 Causes full type information to be output to the ATPs.  This slows
  2623 ATPs down considerably but eliminates a source of unsound "proofs"
  2624 that fail later.
  2625 
  2626 * New method "metisFT": A version of metis that uses full type
  2627 information in order to avoid failures of proof reconstruction.
  2628 
  2629 * New evaluator "approximate" approximates an real valued term using
  2630 the same method as the approximation method.
  2631 
  2632 * Method "approximate" now supports arithmetic expressions as
  2633 boundaries of intervals and implements interval splitting and Taylor
  2634 series expansion.
  2635 
  2636 * ML antiquotation @{code_datatype} inserts definition of a datatype
  2637 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  2638 
  2639 * New theory SupInf of the supremum and infimum operators for sets of
  2640 reals.
  2641 
  2642 * New theory Probability, which contains a development of measure
  2643 theory, eventually leading to Lebesgue integration and probability.
  2644 
  2645 * Extended Multivariate Analysis to include derivation and Brouwer's
  2646 fixpoint theorem.
  2647 
  2648 * Reorganization of number theory, INCOMPATIBILITY:
  2649   - new number theory development for nat and int, in theories Divides
  2650     and GCD as well as in new session Number_Theory
  2651   - some constants and facts now suffixed with _nat and _int
  2652     accordingly
  2653   - former session NumberTheory now named Old_Number_Theory, including
  2654     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  2655   - moved theory Pocklington from src/HOL/Library to
  2656     src/HOL/Old_Number_Theory
  2657 
  2658 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  2659 lcm of finite and infinite sets. It is shown that they form a complete
  2660 lattice.
  2661 
  2662 * Class semiring_div requires superclass no_zero_divisors and proof of
  2663 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  2664 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  2665 generalized to class semiring_div, subsuming former theorems
  2666 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  2667 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  2668 INCOMPATIBILITY.
  2669 
  2670 * Refinements to lattice classes and sets:
  2671   - less default intro/elim rules in locale variant, more default
  2672     intro/elim rules in class variant: more uniformity
  2673   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  2674     le_inf_iff
  2675   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  2676     sup_aci)
  2677   - renamed ACI to inf_sup_aci
  2678   - new class "boolean_algebra"
  2679   - class "complete_lattice" moved to separate theory
  2680     "Complete_Lattice"; corresponding constants (and abbreviations)
  2681     renamed and with authentic syntax:
  2682     Set.Inf ~>    Complete_Lattice.Inf
  2683     Set.Sup ~>    Complete_Lattice.Sup
  2684     Set.INFI ~>   Complete_Lattice.INFI
  2685     Set.SUPR ~>   Complete_Lattice.SUPR
  2686     Set.Inter ~>  Complete_Lattice.Inter
  2687     Set.Union ~>  Complete_Lattice.Union
  2688     Set.INTER ~>  Complete_Lattice.INTER
  2689     Set.UNION ~>  Complete_Lattice.UNION
  2690   - authentic syntax for
  2691     Set.Pow
  2692     Set.image
  2693   - mere abbreviations:
  2694     Set.empty               (for bot)
  2695     Set.UNIV                (for top)
  2696     Set.inter               (for inf, formerly Set.Int)
  2697     Set.union               (for sup, formerly Set.Un)
  2698     Complete_Lattice.Inter  (for Inf)
  2699     Complete_Lattice.Union  (for Sup)
  2700     Complete_Lattice.INTER  (for INFI)
  2701     Complete_Lattice.UNION  (for SUPR)
  2702   - object-logic definitions as far as appropriate
  2703 
  2704 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  2705 Un_subset_iff are explicitly deleted as default simp rules; then also
  2706 their lattice counterparts le_inf_iff and le_sup_iff have to be
  2707 deleted to achieve the desired effect.
  2708 
  2709 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  2710 rules by default any longer; the same applies to min_max.inf_absorb1
  2711 etc.  INCOMPATIBILITY.
  2712 
  2713 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  2714 pred_set_conv by default.  INCOMPATIBILITY.
  2715 
  2716 * Power operations on relations and functions are now one dedicated
  2717 constant "compow" with infix syntax "^^".  Power operation on
  2718 multiplicative monoids retains syntax "^" and is now defined generic
  2719 in class power.  INCOMPATIBILITY.
  2720 
  2721 * Relation composition "R O S" now has a more standard argument order:
  2722 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  2723 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  2724 break, since the O_assoc rule was not rewritten like this.  Fix using
  2725 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  2726 
  2727 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  2728 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  2729 INCOMPATIBILITY.
  2730 
  2731 * Most rules produced by inductive and datatype package have mandatory
  2732 prefixes.  INCOMPATIBILITY.
  2733 
  2734 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  2735 the attribute of the same name.  Each of the theorems in the list
  2736 DERIV_intros assumes composition with an additional function and
  2737 matches a variable to the derivative, which has to be solved by the
  2738 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  2739 of most elementary terms.  Former Maclauren.DERIV_tac and
  2740 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  2741 INCOMPATIBILITY.
  2742 
  2743 * Code generator attributes follow the usual underscore convention:
  2744     code_unfold     replaces    code unfold
  2745     code_post       replaces    code post
  2746     etc.
  2747   INCOMPATIBILITY.
  2748 
  2749 * Renamed methods:
  2750     sizechange -> size_change
  2751     induct_scheme -> induction_schema
  2752   INCOMPATIBILITY.
  2753 
  2754 * Discontinued abbreviation "arbitrary" of constant "undefined".
  2755 INCOMPATIBILITY, use "undefined" directly.
  2756 
  2757 * Renamed theorems:
  2758     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  2759     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  2760     Suc_plus1 -> Suc_eq_plus1
  2761     *anti_sym -> *antisym*
  2762     vector_less_eq_def -> vector_le_def
  2763   INCOMPATIBILITY.
  2764 
  2765 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  2766 INCOMPATIBILITY.
  2767 
  2768 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  2769 INCOMPATIBILITY.
  2770 
  2771 
  2772 *** HOLCF ***
  2773 
  2774 * Theory Representable defines a class "rep" of domains that are
  2775 representable (via an ep-pair) in the universal domain type "udom".
  2776 Instances are provided for all type constructors defined in HOLCF.
  2777 
  2778 * The 'new_domain' command is a purely definitional version of the
  2779 domain package, for representable domains.  Syntax is identical to the
  2780 old domain package.  The 'new_domain' package also supports indirect
  2781 recursion using previously-defined type constructors.  See
  2782 src/HOLCF/ex/New_Domain.thy for examples.
  2783 
  2784 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  2785 on the left-hand side of an equation, and then performs
  2786 simplification.  Rewriting is done using rules declared with the
  2787 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  2788 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  2789 
  2790 * The pattern-match compiler in 'fixrec' can now handle constructors
  2791 with HOL function types.  Pattern-match combinators for the Pair
  2792 constructor are pre-configured.
  2793 
  2794 * The 'fixrec' package now produces better fixed-point induction rules
  2795 for mutually-recursive definitions:  Induction rules have conclusions
  2796 of the form "P foo bar" instead of "P <foo, bar>".
  2797 
  2798 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  2799 been renamed to "below".  The name "below" now replaces "less" in many
  2800 theorem names.  (Legacy theorem names using "less" are still supported
  2801 as well.)
  2802 
  2803 * The 'fixrec' package now supports "bottom patterns".  Bottom
  2804 patterns can be used to generate strictness rules, or to make
  2805 functions more strict (much like the bang-patterns supported by the
  2806 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  2807 examples.
  2808 
  2809 
  2810 *** ML ***
  2811 
  2812 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  2813 errors and run-time exceptions, including detailed source positions.
  2814 
  2815 * Structure Name_Space (formerly NameSpace) now manages uniquely
  2816 identified entries, with some additional information such as source
  2817 position, logical grouping etc.
  2818 
  2819 * Theory and context data is now introduced by the simplified and
  2820 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  2821 to be pure, but the old TheoryDataFun for mutable data (with explicit
  2822 copy operation) is still available for some time.
  2823 
  2824 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2825 provides a high-level programming interface to synchronized state
  2826 variables with atomic update.  This works via pure function
  2827 application within a critical section -- its runtime should be as
  2828 short as possible; beware of deadlocks if critical code is nested,
  2829 either directly or indirectly via other synchronized variables!
  2830 
  2831 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2832 wraps raw ML references, explicitly indicating their non-thread-safe
  2833 behaviour.  The Isar toplevel keeps this structure open, to
  2834 accommodate Proof General as well as quick and dirty interactive
  2835 experiments with references.
  2836 
  2837 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2838 parallel tactical reasoning.
  2839 
  2840 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2841 are similar to SUBPROOF, but are slightly more flexible: only the
  2842 specified parts of the subgoal are imported into the context, and the
  2843 body tactic may introduce new subgoals and schematic variables.
  2844 
  2845 * Old tactical METAHYPS, which does not observe the proof context, has
  2846 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2847 or Subgoal.FOCUS etc.
  2848 
  2849 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2850 functors have their own ML name space there is no point to mark them
  2851 separately.)  Minor INCOMPATIBILITY.
  2852 
  2853 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2854 
  2855 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2856 INCOMPATIBILITY.
  2857 
  2858 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2859 mode, which avoids critical setmp.
  2860 
  2861 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2862 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2863 Attrib/Method.setup introduced in Isabelle2009.
  2864 
  2865 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2866 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2867 last resort.  INCOMPATIBILITY.
  2868 
  2869 * Display.pretty_thm now requires a proper context (cf. former
  2870 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2871 or even Display.pretty_thm_without_context as last resort.
  2872 INCOMPATIBILITY.
  2873 
  2874 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2875 Syntax.pretty_typ/term directly, preferably with proper context
  2876 instead of global theory.
  2877 
  2878 
  2879 *** System ***
  2880 
  2881 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2882 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2883 usedir option -q.
  2884 
  2885 * Support for additional "Isabelle components" via etc/components, see
  2886 also the system manual.
  2887 
  2888 * The isabelle makeall tool now operates on all components with
  2889 IsaMakefile, not just hardwired "logics".
  2890 
  2891 * Removed "compress" option from isabelle-process and isabelle usedir;
  2892 this is always enabled.
  2893 
  2894 * Discontinued support for Poly/ML 4.x versions.
  2895 
  2896 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2897 on a given logic image.  This requires the lighttpd webserver and is
  2898 currently supported on Linux only.
  2899 
  2900 
  2901 
  2902 New in Isabelle2009 (April 2009)
  2903 --------------------------------
  2904 
  2905 *** General ***
  2906 
  2907 * Simplified main Isabelle executables, with less surprises on
  2908 case-insensitive file-systems (such as Mac OS).
  2909 
  2910   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2911     "isatool."
  2912 
  2913   - The former "isabelle" alias for "isabelle-process" has been
  2914     removed (should rarely occur to regular users).
  2915 
  2916   - The former "isabelle-interface" and its alias "Isabelle" have been
  2917     removed (interfaces are now regular Isabelle tools).
  2918 
  2919 Within scripts and make files, the Isabelle environment variables
  2920 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2921 respectively.  (The latter are still available as legacy feature.)
  2922 
  2923 The old isabelle-interface wrapper could react in confusing ways if
  2924 the interface was uninstalled or changed otherwise.  Individual
  2925 interface tool configuration is now more explicit, see also the
  2926 Isabelle system manual.  In particular, Proof General is now available
  2927 via "isabelle emacs".
  2928 
  2929 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2930 purge installed copies of Isabelle executables and re-run "isabelle
  2931 install -p ...", or use symlinks.
  2932 
  2933 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2934 old ~/isabelle, which was slightly non-standard and apt to cause
  2935 surprises on case-insensitive file-systems (such as Mac OS).
  2936 
  2937 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2938 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2939 care is required when using older releases of Isabelle.  Note that
  2940 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2941 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2942 
  2943 * Proofs of fully specified statements are run in parallel on
  2944 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2945 a regular 4-core machine, if the initial heap space is made reasonably
  2946 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2947 
  2948 * The main reference manuals ("isar-ref", "implementation", and
  2949 "system") have been updated and extended.  Formally checked references
  2950 as hyperlinks are now available uniformly.
  2951 
  2952 
  2953 *** Pure ***
  2954 
  2955 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2956 respects.  The most important changes are listed below.  See the
  2957 Tutorial on Locales ("locales" manual) for details.
  2958 
  2959 - In locale expressions, instantiation replaces renaming.  Parameters
  2960 must be declared in a for clause.  To aid compatibility with previous
  2961 parameter inheritance, in locale declarations, parameters that are not
  2962 'touched' (instantiation position "_" or omitted) are implicitly added
  2963 with their syntax at the beginning of the for clause.
  2964 
  2965 - Syntax from abbreviations and definitions in locales is available in
  2966 locale expressions and context elements.  The latter is particularly
  2967 useful in locale declarations.
  2968 
  2969 - More flexible mechanisms to qualify names generated by locale
  2970 expressions.  Qualifiers (prefixes) may be specified in locale
  2971 expressions, and can be marked as mandatory (syntax: "name!:") or
  2972 optional (syntax "name?:").  The default depends for plain "name:"
  2973 depends on the situation where a locale expression is used: in
  2974 commands 'locale' and 'sublocale' prefixes are optional, in
  2975 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2976 implicit qualifiers derived from the parameter names of a locale are
  2977 no longer generated.
  2978 
  2979 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2980 instantiation clause in "interpretation" and "interpret" (square
  2981 brackets) is no longer available.  Use locale expressions.
  2982 
  2983 - When converting proof scripts, mandatory qualifiers in
  2984 'interpretation' and 'interpret' should be retained by default, even
  2985 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2986 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2987 in locale expressions range over a single locale instance only.
  2988 
  2989 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2990 In existing theorem specifications replace the includes element by the
  2991 respective context elements of the included locale, omitting those
  2992 that are already present in the theorem specification.  Multiple
  2993 assume elements of a locale should be replaced by a single one
  2994 involving the locale predicate.  In the proof body, declarations (most
  2995 notably theorems) may be regained by interpreting the respective
  2996 locales in the proof context as required (command "interpret").
  2997 
  2998 If using "includes" in replacement of a target solely because the
  2999 parameter types in the theorem are not as general as in the target,
  3000 consider declaring a new locale with additional type constraints on
  3001 the parameters (context element "constrains").
  3002 
  3003 - Discontinued "locale (open)".  INCOMPATIBILITY.
  3004 
  3005 - Locale interpretation commands no longer attempt to simplify goal.
  3006 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  3007 methods intro_locales and unfold_locales to clarify.
  3008 
  3009 - Locale interpretation commands no longer accept interpretation
  3010 attributes.  INCOMPATIBILITY.
  3011 
  3012 * Class declaration: so-called "base sort" must not be given in import
  3013 list any longer, but is inferred from the specification.  Particularly
  3014 in HOL, write
  3015 
  3016     class foo = ...
  3017 
  3018 instead of
  3019 
  3020     class foo = type + ...
  3021 
  3022 * Class target: global versions of theorems stemming do not carry a
  3023 parameter prefix any longer.  INCOMPATIBILITY.
  3024 
  3025 * Class 'instance' command no longer accepts attached definitions.
  3026 INCOMPATIBILITY, use proper 'instantiation' target instead.
  3027 
  3028 * Recovered hiding of consts, which was accidentally broken in
  3029 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  3030 makes c inaccessible; consider using ``hide (open) const c'' instead.
  3031 
  3032 * Slightly more coherent Pure syntax, with updated documentation in
  3033 isar-ref manual.  Removed locales meta_term_syntax and
  3034 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  3035 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  3036 directly in regular applications.
  3037 
  3038 * There is a new syntactic category "float_const" for signed decimal
  3039 fractions (e.g. 123.45 or -123.45).
  3040 
  3041 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  3042 interface with 'setup' command instead.
  3043 
  3044 * Command 'local_setup' is similar to 'setup', but operates on a local
  3045 theory context.
  3046 
  3047 * The 'axiomatization' command now only works within a global theory
  3048 context.  INCOMPATIBILITY.
  3049 
  3050 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  3051 hypotheses.  Sorts required in the course of reasoning need to be
  3052 covered by the constraints in the initial statement, completed by the
  3053 type instance information of the background theory.  Non-trivial sort
  3054 hypotheses, which rarely occur in practice, may be specified via
  3055 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  3056 
  3057   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  3058 
  3059 The result contains an implicit sort hypotheses as before --
  3060 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  3061 normalization.
  3062 
  3063 * Generalized Isar history, with support for linear undo, direct state
  3064 addressing etc.
  3065 
  3066 * Changed defaults for unify configuration options:
  3067 
  3068   unify_trace_bound = 50 (formerly 25)
  3069   unify_search_bound = 60 (formerly 30)
  3070 
  3071 * Different bookkeeping for code equations (INCOMPATIBILITY):
  3072 
  3073   a) On theory merge, the last set of code equations for a particular
  3074      constant is taken (in accordance with the policy applied by other
  3075      parts of the code generator framework).
  3076 
  3077   b) Code equations stemming from explicit declarations (e.g. code
  3078      attribute) gain priority over default code equations stemming
  3079      from definition, primrec, fun etc.
  3080 
  3081 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  3082 
  3083 * Unified theorem tables for both code generators.  Thus [code
  3084 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  3085 
  3086 * Command 'find_consts' searches for constants based on type and name
  3087 patterns, e.g.
  3088 
  3089     find_consts "_ => bool"
  3090 
  3091 By default, matching is against subtypes, but it may be restricted to
  3092 the whole type.  Searching by name is possible.  Multiple queries are
  3093 conjunctive and queries may be negated by prefixing them with a
  3094 hyphen:
  3095 
  3096     find_consts strict: "_ => bool" name: "Int" -"int => int"
  3097 
  3098 * New 'find_theorems' criterion "solves" matches theorems that
  3099 directly solve the current goal (modulo higher-order unification).
  3100 
  3101 * Auto solve feature for main theorem statements: whenever a new goal
  3102 is stated, "find_theorems solves" is called; any theorems that could
  3103 solve the lemma directly are listed as part of the goal state.
  3104 Cf. associated options in Proof General Isabelle settings menu,
  3105 enabled by default, with reasonable timeout for pathological cases of
  3106 higher-order unification.
  3107 
  3108 
  3109 *** Document preparation ***
  3110 
  3111 * Antiquotation @{lemma} now imitates a regular terminal proof,
  3112 demanding keyword 'by' and supporting the full method expression
  3113 syntax just like the Isar command 'by'.
  3114 
  3115 
  3116 *** HOL ***
  3117 
  3118 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  3119 points Main and Complex_Main remain as before.
  3120 
  3121 * Logic image HOL-Plain provides a minimal HOL with the most important
  3122 tools available (inductive, datatype, primrec, ...).  This facilitates
  3123 experimentation and tool development.  Note that user applications
  3124 (and library theories) should never refer to anything below theory
  3125 Main, as before.
  3126 
  3127 * Logic image HOL-Main stops at theory Main, and thus facilitates
  3128 experimentation due to shorter build times.
  3129 
  3130 * Logic image HOL-NSA contains theories of nonstandard analysis which
  3131 were previously part of former HOL-Complex.  Entry point Hyperreal
  3132 remains valid, but theories formerly using Complex_Main should now use
  3133 new entry point Hypercomplex.
  3134 
  3135 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  3136 Posix processes.  Avoids potentially expensive forking of the ML
  3137 process.  New thread-based implementation also works on non-Unix
  3138 platforms (Cygwin).  Provers are no longer hardwired, but defined
  3139 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  3140 commands are covered in the isar-ref manual.
  3141 
  3142 * Wrapper scripts for remote SystemOnTPTP service allows to use
  3143 sledgehammer without local ATP installation (Vampire etc.). Other
  3144 provers may be included via suitable ML wrappers, see also
  3145 src/HOL/ATP_Linkup.thy.
  3146 
  3147 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  3148 menu.
  3149 
  3150 * The metis method no longer fails because the theorem is too trivial
  3151 (contains the empty clause).
  3152 
  3153 * The metis method now fails in the usual manner, rather than raising
  3154 an exception, if it determines that it cannot prove the theorem.
  3155 
  3156 * Method "coherent" implements a prover for coherent logic (see also
  3157 src/Tools/coherent.ML).
  3158 
  3159 * Constants "undefined" and "default" replace "arbitrary".  Usually
  3160 "undefined" is the right choice to replace "arbitrary", though
  3161 logically there is no difference.  INCOMPATIBILITY.
  3162 
  3163 * Command "value" now integrates different evaluation mechanisms.  The
  3164 result of the first successful evaluation mechanism is printed.  In
  3165 square brackets a particular named evaluation mechanisms may be
  3166 specified (currently, [SML], [code] or [nbe]).  See further
  3167 src/HOL/ex/Eval_Examples.thy.
  3168 
  3169 * Normalization by evaluation now allows non-leftlinear equations.
  3170 Declare with attribute [code nbe].
  3171 
  3172 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  3173 as the structured Isar versions "cases" and "induct", cf. the
  3174 corresponding "cases" and "induct" attributes.  Mutual induction rules
  3175 are now presented as a list of individual projections
  3176 (e.g. foo_bar.inducts for types foo and bar); the old format with
  3177 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  3178 rare situations a different rule is selected --- notably nested tuple
  3179 elimination instead of former prod.exhaust: use explicit (case_tac t
  3180 rule: prod.exhaust) here.
  3181 
  3182 * Attributes "cases", "induct", "coinduct" support "del" option.
  3183 
  3184 * Removed fact "case_split_thm", which duplicates "case_split".
  3185 
  3186 * The option datatype has been moved to a new theory Option.  Renamed
  3187 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  3188 
  3189 * New predicate "strict_mono" classifies strict functions on partial
  3190 orders.  With strict functions on linear orders, reasoning about
  3191 (in)equalities is facilitated by theorems "strict_mono_eq",
  3192 "strict_mono_less_eq" and "strict_mono_less".
  3193 
  3194 * Some set operations are now proper qualified constants with
  3195 authentic syntax.  INCOMPATIBILITY:
  3196 
  3197     op Int ~>   Set.Int
  3198     op Un ~>    Set.Un
  3199     INTER ~>    Set.INTER
  3200     UNION ~>    Set.UNION
  3201     Inter ~>    Set.Inter
  3202     Union ~>    Set.Union
  3203     {} ~>       Set.empty
  3204     UNIV ~>     Set.UNIV
  3205 
  3206 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  3207 theory Set.
  3208 
  3209 * Auxiliary class "itself" has disappeared -- classes without any
  3210 parameter are treated as expected by the 'class' command.
  3211 
  3212 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  3213 
  3214 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  3215 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  3216 
  3217 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  3218 method "approximation".  It proves formulas on real values by using
  3219 interval arithmetic.  In the formulas are also the transcendental
  3220 functions sin, cos, tan, atan, ln, exp and the constant pi are
  3221 allowed. For examples see
  3222 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  3223 
  3224 * Theory "Reflection" now resides in HOL/Library.
  3225 
  3226 * Entry point to Word library now simply named "Word".
  3227 INCOMPATIBILITY.
  3228 
  3229 * Made source layout more coherent with logical distribution
  3230 structure:
  3231 
  3232     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  3233     src/HOL/Library/Code_Message.thy ~> src/HOL/
  3234     src/HOL/Library/GCD.thy ~> src/HOL/
  3235     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  3236     src/HOL/Library/Parity.thy ~> src/HOL/
  3237     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  3238     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  3239     src/HOL/Real/Lubs.thy ~> src/HOL/
  3240     src/HOL/Real/PReal.thy ~> src/HOL/
  3241     src/HOL/Real/Rational.thy ~> src/HOL/
  3242     src/HOL/Real/RComplete.thy ~> src/HOL/
  3243     src/HOL/Real/RealDef.thy ~> src/HOL/
  3244     src/HOL/Real/RealPow.thy ~> src/HOL/
  3245     src/HOL/Real/Real.thy ~> src/HOL/
  3246     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  3247     src/HOL/Complex/Complex.thy ~> src/HOL/
  3248     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  3249     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  3250     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  3251     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  3252     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  3253     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  3254     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  3255     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  3256     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  3257     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  3258     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  3259     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  3260     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  3261     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  3262     src/HOL/Real/Float ~> src/HOL/Library/
  3263     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  3264     src/HOL/Real/RealVector.thy ~> src/HOL/
  3265 
  3266     src/HOL/arith_data.ML ~> src/HOL/Tools
  3267     src/HOL/hologic.ML ~> src/HOL/Tools
  3268     src/HOL/simpdata.ML ~> src/HOL/Tools
  3269     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  3270     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  3271     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  3272     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  3273     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  3274     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  3275     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  3276 
  3277     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  3278     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3279     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3280     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3281     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3282     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3283 
  3284 * If methods "eval" and "evaluation" encounter a structured proof
  3285 state with !!/==>, only the conclusion is evaluated to True (if
  3286 possible), avoiding strange error messages.
  3287 
  3288 * Method "sizechange" automates termination proofs using (a
  3289 modification of) the size-change principle.  Requires SAT solver.  See
  3290 src/HOL/ex/Termination.thy for examples.
  3291 
  3292 * Simplifier: simproc for let expressions now unfolds if bound
  3293 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3294 
  3295 * Method "arith": Linear arithmetic now ignores all inequalities when
  3296 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3297 
  3298 * New attribute "arith" for facts that should always be used
  3299 automatically by arithmetic. It is intended to be used locally in
  3300 proofs, e.g.
  3301 
  3302   assumes [arith]: "x > 0"
  3303 
  3304 Global usage is discouraged because of possible performance impact.
  3305 
  3306 * New classes "top" and "bot" with corresponding operations "top" and
  3307 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3308 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3309 
  3310 * Changed definition lemma "less_fun_def" in order to provide an
  3311 instance for preorders on functions; use lemma "less_le" instead.
  3312 INCOMPATIBILITY.
  3313 
  3314 * Theory Orderings: class "wellorder" moved here, with explicit
  3315 induction rule "less_induct" as assumption.  For instantiation of
  3316 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3317 INCOMPATIBILITY.
  3318 
  3319 * Theory Orderings: added class "preorder" as superclass of "order".
  3320 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3321 etc. slightly changed.  Some theorems named order_class.* now named
  3322 preorder_class.*.
  3323 
  3324 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3325 "diag" to "Id_on".
  3326 
  3327 * Theory Finite_Set: added a new fold combinator of type
  3328 
  3329   ('a => 'b => 'b) => 'b => 'a set => 'b
  3330 
  3331 Occasionally this is more convenient than the old fold combinator
  3332 which is now defined in terms of the new one and renamed to
  3333 fold_image.
  3334 
  3335 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3336 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3337 extended with further lemmas!).  At the moment both still exist but
  3338 the former will disappear at some point.
  3339 
  3340 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3341 class recpower.  Type-specific simp rules for various recpower types
  3342 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3343 
  3344 rat_power_0    -> power_0
  3345 rat_power_Suc  -> power_Suc
  3346 realpow_0      -> power_0
  3347 realpow_Suc    -> power_Suc
  3348 complexpow_0   -> power_0
  3349 complexpow_Suc -> power_Suc
  3350 power_poly_0   -> power_0
  3351 power_poly_Suc -> power_Suc
  3352 
  3353 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3354 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3355 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3356 of lemmas from Divides has been generalized from nat to class
  3357 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3358 renames resulting from duplicate elimination:
  3359 
  3360     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3361     zero_dvd_iff ~>         dvd_0_left_iff
  3362     dvd_0 ~>                dvd_0_right
  3363     DIVISION_BY_ZERO_DIV ~> div_by_0
  3364     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3365     mult_div ~>             div_mult_self2_is_id
  3366     mult_mod ~>             mod_mult_self2_is_0
  3367 
  3368 * Theory IntDiv: removed many lemmas that are instances of class-based
  3369 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3370 rename old lemmas as follows:
  3371 
  3372 dvd_diff               -> nat_dvd_diff
  3373 dvd_zminus_iff         -> dvd_minus_iff
  3374 mod_add1_eq            -> mod_add_eq
  3375 mod_mult1_eq           -> mod_mult_right_eq
  3376 mod_mult1_eq'          -> mod_mult_left_eq
  3377 mod_mult_distrib_mod   -> mod_mult_eq
  3378 nat_mod_add_left_eq    -> mod_add_left_eq
  3379 nat_mod_add_right_eq   -> mod_add_right_eq
  3380 nat_mod_div_trivial    -> mod_div_trivial
  3381 nat_mod_mod_trivial    -> mod_mod_trivial
  3382 zdiv_zadd_self1        -> div_add_self1
  3383 zdiv_zadd_self2        -> div_add_self2
  3384 zdiv_zmult_self1       -> div_mult_self2_is_id
  3385 zdiv_zmult_self2       -> div_mult_self1_is_id
  3386 zdvd_triv_left         -> dvd_triv_left
  3387 zdvd_triv_right        -> dvd_triv_right
  3388 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3389 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3390 zmod_zadd_left_eq      -> mod_add_left_eq
  3391 zmod_zadd_right_eq     -> mod_add_right_eq
  3392 zmod_zadd_self1        -> mod_add_self1
  3393 zmod_zadd_self2        -> mod_add_self2
  3394 zmod_zadd1_eq          -> mod_add_eq
  3395 zmod_zdiff1_eq         -> mod_diff_eq
  3396 zmod_zdvd_zmod         -> mod_mod_cancel
  3397 zmod_zmod_cancel       -> mod_mod_cancel
  3398 zmod_zmult_self1       -> mod_mult_self2_is_0
  3399 zmod_zmult_self2       -> mod_mult_self1_is_0
  3400 zmod_1                 -> mod_by_1
  3401 zdiv_1                 -> div_by_1
  3402 zdvd_abs1              -> abs_dvd_iff
  3403 zdvd_abs2              -> dvd_abs_iff
  3404 zdvd_refl              -> dvd_refl
  3405 zdvd_trans             -> dvd_trans
  3406 zdvd_zadd              -> dvd_add
  3407 zdvd_zdiff             -> dvd_diff
  3408 zdvd_zminus_iff        -> dvd_minus_iff
  3409 zdvd_zminus2_iff       -> minus_dvd_iff
  3410 zdvd_zmultD            -> dvd_mult_right
  3411 zdvd_zmultD2           -> dvd_mult_left
  3412 zdvd_zmult_mono        -> mult_dvd_mono
  3413 zdvd_0_right           -> dvd_0_right
  3414 zdvd_0_left            -> dvd_0_left_iff
  3415 zdvd_1_left            -> one_dvd
  3416 zminus_dvd_iff         -> minus_dvd_iff
  3417 
  3418 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3419 
  3420 * The real numbers offer decimal input syntax: 12.34 is translated
  3421 into 1234/10^2. This translation is not reversed upon output.
  3422 
  3423 * Theory Library/Polynomial defines an abstract type 'a poly of
  3424 univariate polynomials with coefficients of type 'a.  In addition to
  3425 the standard ring operations, it also supports div and mod.  Code
  3426 generation is also supported, using list-style constructors.
  3427 
  3428 * Theory Library/Inner_Product defines a class of real_inner for real
  3429 inner product spaces, with an overloaded operation inner :: 'a => 'a
  3430 => real.  Class real_inner is a subclass of real_normed_vector from
  3431 theory RealVector.
  3432 
  3433 * Theory Library/Product_Vector provides instances for the product
  3434 type 'a * 'b of several classes from RealVector and Inner_Product.
  3435 Definitions of addition, subtraction, scalar multiplication, norms,
  3436 and inner products are included.
  3437 
  3438 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  3439 addition to the field operations, numerals and case syntax are also
  3440 supported.
  3441 
  3442 * Theory Library/Diagonalize provides constructive version of Cantor's
  3443 first diagonalization argument.
  3444 
  3445 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  3446 zlcm (for int); carried together from various gcd/lcm developements in
  3447 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  3448 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  3449 may recover tupled syntax as follows:
  3450 
  3451     hide (open) const gcd
  3452     abbreviation gcd where
  3453       "gcd == (%(a, b). GCD.gcd a b)"
  3454     notation (output)
  3455       GCD.gcd ("gcd '(_, _')")
  3456 
  3457 The same works for lcm, zgcd, zlcm.
  3458 
  3459 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  3460 instantiations for algebraic structures.  Removed some duplicate
  3461 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  3462 
  3463 * ML antiquotation @{code} takes a constant as argument and generates
  3464 corresponding code in background and inserts name of the corresponding
  3465 resulting ML value/function/datatype constructor binding in place.
  3466 All occurrences of @{code} with a single ML block are generated
  3467 simultaneously.  Provides a generic and safe interface for
  3468 instrumentalizing code generation.  See
  3469 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  3470 In future you ought to refrain from ad-hoc compiling generated SML
  3471 code on the ML toplevel.  Note that (for technical reasons) @{code}
  3472 cannot refer to constants for which user-defined serializations are
  3473 set.  Refer to the corresponding ML counterpart directly in that
  3474 cases.
  3475 
  3476 * Command 'rep_datatype': instead of theorem names the command now
  3477 takes a list of terms denoting the constructors of the type to be
  3478 represented as datatype.  The characteristic theorems have to be
  3479 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  3480 have disappeared in favour of existing ones:
  3481 
  3482     unit_induct                 ~> unit.induct
  3483     prod_induct                 ~> prod.induct
  3484     sum_induct                  ~> sum.induct
  3485     Suc_Suc_eq                  ~> nat.inject
  3486     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  3487 
  3488 
  3489 *** HOL-Algebra ***
  3490 
  3491 * New locales for orders and lattices where the equivalence relation
  3492 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  3493 locales use a record structure with field eq for the equivalence.
  3494 
  3495 * New theory of factorial domains.
  3496 
  3497 * Units_l_inv and Units_r_inv are now simp rules by default.
  3498 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  3499 and/or r_inv will now also require deletion of these lemmas.
  3500 
  3501 * Renamed the following theorems, INCOMPATIBILITY:
  3502 
  3503 UpperD ~> Upper_memD
  3504 LowerD ~> Lower_memD
  3505 least_carrier ~> least_closed
  3506 greatest_carrier ~> greatest_closed
  3507 greatest_Lower_above ~> greatest_Lower_below
  3508 one_zero ~> carrier_one_zero
  3509 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  3510 
  3511 
  3512 *** HOL-Nominal ***
  3513 
  3514 * Nominal datatypes can now contain type-variables.
  3515 
  3516 * Commands 'nominal_inductive' and 'equivariance' work with local
  3517 theory targets.
  3518 
  3519 * Nominal primrec can now works with local theory targets and its
  3520 specification syntax now conforms to the general format as seen in
  3521 'inductive' etc.
  3522 
  3523 * Method "perm_simp" honours the standard simplifier attributes
  3524 (no_asm), (no_asm_use) etc.
  3525 
  3526 * The new predicate #* is defined like freshness, except that on the
  3527 left hand side can be a set or list of atoms.
  3528 
  3529 * Experimental command 'nominal_inductive2' derives strong induction
  3530 principles for inductive definitions.  In contrast to
  3531 'nominal_inductive', which can only deal with a fixed number of
  3532 binders, it can deal with arbitrary expressions standing for sets of
  3533 atoms to be avoided.  The only inductive definition we have at the
  3534 moment that needs this generalisation is the typing rule for Lets in
  3535 the algorithm W:
  3536 
  3537  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  3538  -----------------------------------------------------------------
  3539          Gamma |- Let x be t1 in t2 : T2
  3540 
  3541 In this rule one wants to avoid all the binders that are introduced by
  3542 "close Gamma T1".  We are looking for other examples where this
  3543 feature might be useful.  Please let us know.
  3544 
  3545 
  3546 *** HOLCF ***
  3547 
  3548 * Reimplemented the simplification procedure for proving continuity
  3549 subgoals.  The new simproc is extensible; users can declare additional
  3550 continuity introduction rules with the attribute [cont2cont].
  3551 
  3552 * The continuity simproc now uses a different introduction rule for
  3553 solving continuity subgoals on terms with lambda abstractions.  In
  3554 some rare cases the new simproc may fail to solve subgoals that the
  3555 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  3556 Potential INCOMPATIBILITY.
  3557 
  3558 * Command 'fixrec': specification syntax now conforms to the general
  3559 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  3560 examples.  INCOMPATIBILITY.
  3561 
  3562 
  3563 *** ZF ***
  3564 
  3565 * Proof of Zorn's Lemma for partial orders.
  3566 
  3567 
  3568 *** ML ***
  3569 
  3570 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  3571 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  3572 depends on multithreading, so timouts will not work before Poly/ML
  3573 5.2.1!
  3574 
  3575 * High-level support for concurrent ML programming, see
  3576 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  3577 particularly convenient to organize independent functional
  3578 computations.  The concept of "synchronized variables" provides a
  3579 higher-order interface for components with shared state, avoiding the
  3580 delicate details of mutexes and condition variables.  (Requires
  3581 Poly/ML 5.2.1 or later.)
  3582 
  3583 * ML bindings produced via Isar commands are stored within the Isar
  3584 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  3585 become thread-safe and work with undo as expected (concerning
  3586 top-level bindings, not side-effects on global references).
  3587 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  3588 compiler at runtime; really global bindings need to be given outside a
  3589 theory.  (Requires Poly/ML 5.2 or later.)
  3590 
  3591 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  3592 context.  Top-level ML bindings are stored within the proof context in
  3593 a purely sequential fashion, disregarding the nested proof structure.
  3594 ML bindings introduced by 'ML_prf' are discarded at the end of the
  3595 proof.  (Requires Poly/ML 5.2 or later.)
  3596 
  3597 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  3598 and Method.setup, as well as Isar commands 'attribute_setup' and
  3599 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  3600 existing code accordingly, or use plain 'setup' together with old
  3601 Method.add_method.
  3602 
  3603 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  3604 to 'a -> thm, while results are always tagged with an authentic oracle
  3605 name.  The Isar command 'oracle' is now polymorphic, no argument type
  3606 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  3607 accordingly.  Note that extra performance may be gained by producing
  3608 the cterm carefully, avoiding slow Thm.cterm_of.
  3609 
  3610 * Simplified interface for defining document antiquotations via
  3611 ThyOutput.antiquotation, ThyOutput.output, and optionally
  3612 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  3613 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  3614 examples.
  3615 
  3616 * More systematic treatment of long names, abstract name bindings, and
  3617 name space operations.  Basic operations on qualified names have been
  3618 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  3619 Long_Name.append.  Old type bstring has been mostly replaced by
  3620 abstract type binding (see structure Binding), which supports precise
  3621 qualification by packages and local theory targets, as well as proper
  3622 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  3623 bstring values into Binding.name, or better pass through abstract
  3624 bindings everywhere.  See further src/Pure/General/long_name.ML,
  3625 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  3626 
  3627 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  3628 LocalTheory.note etc.) now refer to the *full* internal name, not the
  3629 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  3630 
  3631 * Disposed old type and term read functions (Sign.read_def_typ,
  3632 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  3633 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  3634 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  3635 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  3636 resort for legacy applications.
  3637 
  3638 * Disposed old declarations, tactics, tactic combinators that refer to
  3639 the simpset or claset of an implicit theory (such as Addsimps,
  3640 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  3641 embedded ML text, or local_simpset_of with a proper context passed as
  3642 explicit runtime argument.
  3643 
  3644 * Rules and tactics that read instantiations (read_instantiate,
  3645 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  3646 context, which is required for parsing and type-checking.  Moreover,
  3647 the variables are specified as plain indexnames, not string encodings
  3648 thereof.  INCOMPATIBILITY.
  3649 
  3650 * Generic Toplevel.add_hook interface allows to analyze the result of
  3651 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  3652 for theorem dependency output of transactions resulting in a new
  3653 theory state.
  3654 
  3655 * ML antiquotations: block-structured compilation context indicated by
  3656 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  3657 
  3658   @{binding name}                         - basic name binding
  3659   @{let ?pat = term}                      - term abbreviation (HO matching)
  3660   @{note name = fact}                     - fact abbreviation
  3661   @{thm fact}                             - singleton fact (with attributes)
  3662   @{thms fact}                            - general fact (with attributes)
  3663   @{lemma prop by method}                 - singleton goal
  3664   @{lemma prop by meth1 meth2}            - singleton goal
  3665   @{lemma prop1 ... propN by method}      - general goal
  3666   @{lemma prop1 ... propN by meth1 meth2} - general goal
  3667   @{lemma (open) ...}                     - open derivation
  3668 
  3669 
  3670 *** System ***
  3671 
  3672 * The Isabelle "emacs" tool provides a specific interface to invoke
  3673 Proof General / Emacs, with more explicit failure if that is not
  3674 installed (the old isabelle-interface script silently falls back on
  3675 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  3676 installation location of the Proof General distribution.
  3677 
  3678 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  3679 the Isabelle process into a JVM/Scala application.  See
  3680 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  3681 process wrapper has been discontinued.)
  3682 
  3683 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  3684 
  3685 * Various status messages (with exact source position information) are
  3686 emitted, if proper markup print mode is enabled.  This allows
  3687 user-interface components to provide detailed feedback on internal
  3688 prover operations.
  3689 
  3690 
  3691 
  3692 New in Isabelle2008 (June 2008)
  3693 -------------------------------
  3694 
  3695 *** General ***
  3696 
  3697 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  3698 and updated, with formally checked references as hyperlinks.
  3699 
  3700 * Theory loader: use_thy (and similar operations) no longer set the
  3701 implicit ML context, which was occasionally hard to predict and in
  3702 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  3703 provides a proper context already.
  3704 
  3705 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3706 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  3707 'use' within a theory file will do the job.
  3708 
  3709 * Name space merge now observes canonical order, i.e. the second space
  3710 is inserted into the first one, while existing entries in the first
  3711 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  3712 swap theory imports.
  3713 
  3714 * Syntax: symbol \<chi> is now considered a letter.  Potential
  3715 INCOMPATIBILITY in identifier syntax etc.
  3716 
  3717 * Outer syntax: string tokens no longer admit escaped white space,
  3718 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  3719 white space without escapes.
  3720 
  3721 * Outer syntax: string tokens may contain arbitrary character codes
  3722 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  3723 "foo_bar".
  3724 
  3725 
  3726 *** Pure ***
  3727 
  3728 * Context-dependent token translations.  Default setup reverts locally
  3729 fixed variables, and adds hilite markup for undeclared frees.
  3730 
  3731 * Unused theorems can be found using the new command 'unused_thms'.
  3732 There are three ways of invoking it:
  3733 
  3734 (1) unused_thms
  3735      Only finds unused theorems in the current theory.
  3736 
  3737 (2) unused_thms thy_1 ... thy_n -
  3738      Finds unused theorems in the current theory and all of its ancestors,
  3739      excluding the theories thy_1 ... thy_n and all of their ancestors.
  3740 
  3741 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  3742      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  3743      their ancestors, excluding the theories thy_1 ... thy_n and all of
  3744      their ancestors.
  3745 
  3746 In order to increase the readability of the list produced by
  3747 unused_thms, theorems that have been created by a particular instance
  3748 of a theory command such as 'inductive' or 'function' are considered
  3749 to belong to the same "group", meaning that if at least one theorem in
  3750 this group is used, the other theorems in the same group are no longer
  3751 reported as unused.  Moreover, if all theorems in the group are
  3752 unused, only one theorem in the group is displayed.
  3753 
  3754 Note that proof objects have to be switched on in order for
  3755 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  3756 usually the case when using Proof General with the default settings).
  3757 
  3758 * Authentic naming of facts disallows ad-hoc overwriting of previous
  3759 theorems within the same name space.  INCOMPATIBILITY, need to remove
  3760 duplicate fact bindings, or even accidental fact duplications.  Note
  3761 that tools may maintain dynamically scoped facts systematically, using
  3762 PureThy.add_thms_dynamic.
  3763 
  3764 * Command 'hide' now allows to hide from "fact" name space as well.
  3765 
  3766 * Eliminated destructive theorem database, simpset, claset, and
  3767 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  3768 update of theories within ML code.
  3769 
  3770 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  3771 INCOMPATIBILITY, object-logics depending on former Pure require
  3772 additional setup PureThy.old_appl_syntax_setup; object-logics
  3773 depending on former CPure need to refer to Pure.
  3774 
  3775 * Commands 'use' and 'ML' are now purely functional, operating on
  3776 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  3777 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  3778 INCOMPATIBILITY.
  3779 
  3780 * Command 'setup': discontinued implicit version with ML reference.
  3781 
  3782 * Instantiation target allows for simultaneous specification of class
  3783 instance operations together with an instantiation proof.
  3784 Type-checking phase allows to refer to class operations uniformly.
  3785 See src/HOL/Complex/Complex.thy for an Isar example and
  3786 src/HOL/Library/Eval.thy for an ML example.
  3787 
  3788 * Indexing of literal facts: be more serious about including only
  3789 facts from the visible specification/proof context, but not the
  3790 background context (locale etc.).  Affects `prop` notation and method
  3791 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  3792 situations.
  3793 
  3794 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  3795 "(open)" option, which used to expose internal bound variables to the
  3796 proof text.
  3797 
  3798 * Isar statements: removed obsolete case "rule_context".
  3799 INCOMPATIBILITY, better use explicit fixes/assumes.
  3800 
  3801 * Locale proofs: default proof step now includes 'unfold_locales';
  3802 hence 'proof' without argument may be used to unfold locale
  3803 predicates.
  3804 
  3805 
  3806 *** Document preparation ***
  3807 
  3808 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  3809 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  3810 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  3811 spot); renamed link color from "darkblue" to "linkcolor" (default
  3812 value unchanged, can be redefined via \definecolor); no longer sets
  3813 "a4paper" option (unnecessary or even intrusive).
  3814 
  3815 * Antiquotation @{lemma A method} proves proposition A by the given
  3816 method (either a method name or a method name plus (optional) method
  3817 arguments in parentheses) and prints A just like @{prop A}.
  3818 
  3819 
  3820 *** HOL ***
  3821 
  3822 * New primrec package.  Specification syntax conforms in style to
  3823 definition/function/....  No separate induction rule is provided.  The
  3824 "primrec" command distinguishes old-style and new-style specifications
  3825 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3826 When adjusting theories, beware: constants stemming from new-style
  3827 primrec specifications have authentic syntax.
  3828 
  3829 * Metis prover is now an order of magnitude faster, and also works
  3830 with multithreading.
  3831 
  3832 * Metis: the maximum number of clauses that can be produced from a
  3833 theorem is now given by the attribute max_clauses.  Theorems that
  3834 exceed this number are ignored, with a warning printed.
  3835 
  3836 * Sledgehammer no longer produces structured proofs by default. To
  3837 enable, declare [[sledgehammer_full = true]].  Attributes
  3838 reconstruction_modulus, reconstruction_sorts renamed
  3839 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3840 
  3841 * Method "induct_scheme" derives user-specified induction rules
  3842 from well-founded induction and completeness of patterns. This factors
  3843 out some operations that are done internally by the function package
  3844 and makes them available separately.  See
  3845 src/HOL/ex/Induction_Scheme.thy for examples.
  3846 
  3847 * More flexible generation of measure functions for termination
  3848 proofs: Measure functions can be declared by proving a rule of the
  3849 form "is_measure f" and giving it the [measure_function] attribute.
  3850 The "is_measure" predicate is logically meaningless (always true), and
  3851 just guides the heuristic.  To find suitable measure functions, the
  3852 termination prover sets up the goal "is_measure ?f" of the appropriate
  3853 type and generates all solutions by prolog-style backwards proof using
  3854 the declared rules.
  3855 
  3856 This setup also deals with rules like 
  3857 
  3858   "is_measure f ==> is_measure (list_size f)"
  3859 
  3860 which accommodates nested datatypes that recurse through lists.
  3861 Similar rules are predeclared for products and option types.
  3862 
  3863 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3864 
  3865   INCOMPATIBILITIES:
  3866 
  3867   - Definitions of overloaded constants on sets have to be replaced by
  3868     definitions on => and bool.
  3869 
  3870   - Some definitions of overloaded operators on sets can now be proved
  3871     using the definitions of the operators on => and bool.  Therefore,
  3872     the following theorems have been renamed:
  3873 
  3874       subset_def   -> subset_eq
  3875       psubset_def  -> psubset_eq
  3876       set_diff_def -> set_diff_eq
  3877       Compl_def    -> Compl_eq
  3878       Sup_set_def  -> Sup_set_eq
  3879       Inf_set_def  -> Inf_set_eq
  3880       sup_set_def  -> sup_set_eq
  3881       inf_set_def  -> inf_set_eq
  3882 
  3883   - Due to the incompleteness of the HO unification algorithm, some
  3884     rules such as subst may require manual instantiation, if some of
  3885     the unknowns in the rule is a set.
  3886 
  3887   - Higher order unification and forward proofs:
  3888     The proof pattern
  3889 
  3890       have "P (S::'a set)" <...>
  3891       then have "EX S. P S" ..
  3892 
  3893     no longer works (due to the incompleteness of the HO unification
  3894     algorithm) and must be replaced by the pattern
  3895 
  3896       have "EX S. P S"
  3897       proof
  3898         show "P S" <...>
  3899       qed
  3900 
  3901   - Calculational reasoning with subst (or similar rules):
  3902     The proof pattern
  3903 
  3904       have "P (S::'a set)" <...>
  3905       also have "S = T" <...>
  3906       finally have "P T" .
  3907 
  3908     no longer works (for similar reasons as the previous example) and
  3909     must be replaced by something like
  3910 
  3911       have "P (S::'a set)" <...>
  3912       moreover have "S = T" <...>
  3913       ultimately have "P T" by simp
  3914 
  3915   - Tactics or packages written in ML code:
  3916     Code performing pattern matching on types via
  3917 
  3918       Type ("set", [T]) => ...
  3919 
  3920     must be rewritten. Moreover, functions like strip_type or
  3921     binder_types no longer return the right value when applied to a
  3922     type of the form
  3923 
  3924       T1 => ... => Tn => U => bool
  3925 
  3926     rather than
  3927 
  3928       T1 => ... => Tn => U set
  3929 
  3930 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3931 Wellfounded_Relations to theory Wellfounded.
  3932 
  3933 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3934 
  3935 * Class finite no longer treats UNIV as class parameter.  Use class
  3936 enum from theory Library/Enum instead to achieve a similar effect.
  3937 INCOMPATIBILITY.
  3938 
  3939 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3940 and "Cons".  INCOMPATIBILITY.
  3941 
  3942 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3943 Potential INCOMPATIBILITY.
  3944 
  3945 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3946 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3947 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3948 
  3949 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3950 the same name in theory Orderings:
  3951 
  3952   less_trans
  3953   less_linear
  3954   le_imp_less_or_eq
  3955   le_less_trans
  3956   less_le_trans
  3957   less_not_sym
  3958   less_asym
  3959 
  3960 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3961 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3962 and different variable names.
  3963 
  3964 * Library/Option_ord.thy: Canonical order on option type.
  3965 
  3966 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3967 finite maps.
  3968 
  3969 * Library/Countable.thy: Type class for countable types.
  3970 
  3971 * Theory Int: The representation of numerals has changed.  The infix
  3972 operator BIT and the bit datatype with constructors B0 and B1 have
  3973 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3974 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3975 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3976 accordingly.
  3977 
  3978 * Theory Nat: definition of <= and < on natural numbers no longer
  3979 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3980 le_def and less_def have disappeared.  Consider lemmas not_less
  3981 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3982 
  3983 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3984 (whose purpose mainly is for various fold_set functionals) have been
  3985 abandoned in favor of the existing algebraic classes
  3986 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3987 lower_semilattice (resp. upper_semilattice) and linorder.
  3988 INCOMPATIBILITY.
  3989 
  3990 * Theory Transitive_Closure: induct and cases rules now declare proper
  3991 case_names ("base" and "step").  INCOMPATIBILITY.
  3992 
  3993 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3994 lattices.  The form set-specific version is available as
  3995 Inductive.lfp_ordinal_induct_set.
  3996 
  3997 * Renamed theorems "power.simps" to "power_int.simps".
  3998 INCOMPATIBILITY.
  3999 
  4000 * Class semiring_div provides basic abstract properties of semirings
  4001 with division and modulo operations.  Subsumes former class dvd_mod.
  4002 
  4003 * Merged theories IntDef, Numeral and IntArith into unified theory
  4004 Int.  INCOMPATIBILITY.
  4005 
  4006 * Theory Library/Code_Index: type "index" now represents natural
  4007 numbers rather than integers.  INCOMPATIBILITY.
  4008 
  4009 * New class "uminus" with operation "uminus" (split of from class
  4010 "minus" which now only has operation "minus", binary).
  4011 INCOMPATIBILITY.
  4012 
  4013 * Constants "card", "internal_split", "option_map" now with authentic
  4014 syntax.  INCOMPATIBILITY.
  4015 
  4016 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  4017 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  4018 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  4019 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  4020 Sup_set_def, le_def, less_def, option_map_def now with object
  4021 equality.  INCOMPATIBILITY.
  4022 
  4023 * Records. Removed K_record, and replaced it by pure lambda term
  4024 %x. c. The simplifier setup is now more robust against eta expansion.
  4025 INCOMPATIBILITY: in cases explicitly referring to K_record.
  4026 
  4027 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  4028 
  4029 * Library/ListVector: new theory of arithmetic vector operations.
  4030 
  4031 * Library/Order_Relation: new theory of various orderings as sets of
  4032 pairs.  Defines preorders, partial orders, linear orders and
  4033 well-orders on sets and on types.
  4034 
  4035 
  4036 *** ZF ***
  4037 
  4038 * Renamed some theories to allow to loading both ZF and HOL in the
  4039 same session:
  4040 
  4041   Datatype  -> Datatype_ZF
  4042   Inductive -> Inductive_ZF
  4043   Int       -> Int_ZF
  4044   IntDiv    -> IntDiv_ZF
  4045   Nat       -> Nat_ZF
  4046   List      -> List_ZF
  4047   Main      -> Main_ZF
  4048 
  4049 INCOMPATIBILITY: ZF theories that import individual theories below
  4050 Main might need to be adapted.  Regular theory Main is still
  4051 available, as trivial extension of Main_ZF.
  4052 
  4053 
  4054 *** ML ***
  4055 
  4056 * ML within Isar: antiquotation @{const name} or @{const
  4057 name(typargs)} produces statically-checked Const term.
  4058 
  4059 * Functor NamedThmsFun: data is available to the user as dynamic fact
  4060 (of the same name).  Removed obsolete print command.
  4061 
  4062 * Removed obsolete "use_legacy_bindings" function.
  4063 
  4064 * The ``print mode'' is now a thread-local value derived from a global
  4065 template (the former print_mode reference), thus access becomes
  4066 non-critical.  The global print_mode reference is for session
  4067 management only; user-code should use print_mode_value,
  4068 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  4069 
  4070 * Functions system/system_out provide a robust way to invoke external
  4071 shell commands, with propagation of interrupts (requires Poly/ML
  4072 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  4073 
  4074 
  4075 *** System ***
  4076 
  4077 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  4078 in accordance with Proof General 3.7, which prefers GNU emacs.
  4079 
  4080 * isatool tty runs Isabelle process with plain tty interaction;
  4081 optional line editor may be specified via ISABELLE_LINE_EDITOR
  4082 setting, the default settings attempt to locate "ledit" and "rlwrap".
  4083 
  4084 * isatool browser now works with Cygwin as well, using general
  4085 "javapath" function defined in Isabelle process environment.
  4086 
  4087 * YXML notation provides a simple and efficient alternative to
  4088 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  4089 isatool yxml as described in the Isabelle system manual.
  4090 
  4091 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  4092 provides general wrapper for managing an Isabelle process in a robust
  4093 fashion, with ``cooked'' output from stdin/stderr.
  4094 
  4095 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  4096 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  4097 
  4098 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  4099 way of changing the user's settings is via
  4100 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  4101 script.
  4102 
  4103 * Multithreading.max_threads := 0 refers to the number of actual CPU
  4104 cores of the underlying machine, which is a good starting point for
  4105 optimal performance tuning.  The corresponding usedir option -M allows
  4106 "max" as an alias for "0".  WARNING: does not work on certain versions
  4107 of Mac OS (with Poly/ML 5.1).
  4108 
  4109 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  4110 adverse effect of Isabelle flooding interactive front-ends (notably
  4111 ProofGeneral / XEmacs).
  4112 
  4113 
  4114 
  4115 New in Isabelle2007 (November 2007)
  4116 -----------------------------------
  4117 
  4118 *** General ***
  4119 
  4120 * More uniform information about legacy features, notably a
  4121 warning/error of "Legacy feature: ...", depending on the state of the
  4122 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  4123 legacy features will disappear eventually.
  4124 
  4125 * Theory syntax: the header format ``theory A = B + C:'' has been
  4126 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  4127 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  4128 
  4129 * Theory syntax: the old non-Isar theory file format has been
  4130 discontinued altogether.  Note that ML proof scripts may still be used
  4131 with Isar theories; migration is usually quite simple with the ML
  4132 function use_legacy_bindings.  INCOMPATIBILITY.
  4133 
  4134 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  4135 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  4136 quotes.
  4137 
  4138 * Theory loader: be more serious about observing the static theory
  4139 header specifications (including optional directories), but not the
  4140 accidental file locations of previously successful loads.  The strict
  4141 update policy of former update_thy is now already performed by
  4142 use_thy, so the former has been removed; use_thys updates several
  4143 theories simultaneously, just as 'imports' within a theory header
  4144 specification, but without merging the results.  Potential
  4145 INCOMPATIBILITY: may need to refine theory headers and commands
  4146 ROOT.ML which depend on load order.
  4147 
  4148 * Theory loader: optional support for content-based file
  4149 identification, instead of the traditional scheme of full physical
  4150 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  4151 (cf. the system manual).  The new scheme allows to work with
  4152 non-finished theories in persistent session images, such that source
  4153 files may be moved later on without requiring reloads.
  4154 
  4155 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4156 file (with the same base name as the theory) are considered a legacy
  4157 feature, which will disappear eventually. Even now, the theory loader
  4158 no longer maintains dependencies on such files.
  4159 
  4160 * Syntax: the scope for resolving ambiguities via type-inference is
  4161 now limited to individual terms, instead of whole simultaneous
  4162 specifications as before. This greatly reduces the complexity of the
  4163 syntax module and improves flexibility by separating parsing and
  4164 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  4165 'fixes' etc.) are required in rare situations.
  4166 
  4167 * Syntax: constants introduced by new-style packages ('definition',
  4168 'abbreviation' etc.) are passed through the syntax module in
  4169 ``authentic mode''. This means that associated mixfix annotations
  4170 really stick to such constants, independently of potential name space
  4171 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  4172 trees are represented slightly differently, may need to adapt syntax
  4173 translations accordingly. Use CONST marker in 'translations' and
  4174 @{const_syntax} antiquotation in 'parse_translation' etc.
  4175 
  4176 * Legacy goal package: reduced interface to the bare minimum required
  4177 to keep existing proof scripts running.  Most other user-level
  4178 functions are now part of the OldGoals structure, which is *not* open
  4179 by default (consider isatool expandshort before open OldGoals).
  4180 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  4181 these tend to cause confusion about the actual goal (!) context being
  4182 used here, which is not necessarily the same as the_context().
  4183 
  4184 * Command 'find_theorems': supports "*" wild-card in "name:"
  4185 criterion; "with_dups" option.  Certain ProofGeneral versions might
  4186 support a specific search form (see ProofGeneral/CHANGES).
  4187 
  4188 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  4189 by default, which means that "prems" (and also "fixed variables") are
  4190 suppressed from proof state output.  Note that the ProofGeneral
  4191 settings mechanism allows to change and save options persistently, but
  4192 older versions of Isabelle will fail to start up if a negative prems
  4193 limit is imposed.
  4194 
  4195 * Local theory targets may be specified by non-nested blocks of
  4196 ``context/locale/class ... begin'' followed by ``end''.  The body may
  4197 contain definitions, theorems etc., including any derived mechanism
  4198 that has been implemented on top of these primitives.  This concept
  4199 generalizes the existing ``theorem (in ...)'' towards more versatility
  4200 and scalability.
  4201 
  4202 * Proof General interface: proper undo of final 'end' command;
  4203 discontinued Isabelle/classic mode (ML proof scripts).
  4204 
  4205 
  4206 *** Document preparation ***
  4207 
  4208 * Added antiquotation @{theory name} which prints the given name,
  4209 after checking that it refers to a valid ancestor theory in the
  4210 current context.
  4211 
  4212 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  4213 check the given source text as ML type/structure, printing verbatim.
  4214 
  4215 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  4216 "c args == rhs" given in the current context.  (Any number of
  4217 arguments may be given on the LHS.)
  4218 
  4219 
  4220 *** Pure ***
  4221 
  4222 * The 'class' package offers a combination of axclass and locale to
  4223 achieve Haskell-like type classes in Isabelle.  Definitions and
  4224 theorems within a class context produce both relative results (with
  4225 implicit parameters according to the locale context), and polymorphic
  4226 constants with qualified polymorphism (according to the class
  4227 context).  Within the body context of a 'class' target, a separate
  4228 syntax layer ("user space type system") takes care of converting
  4229 between global polymorphic consts and internal locale representation.
  4230 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  4231 "isatool doc classes" provides a tutorial.
  4232 
  4233 * Generic code generator framework allows to generate executable
  4234 code for ML and Haskell (including Isabelle classes).  A short usage
  4235 sketch:
  4236 
  4237     internal compilation:
  4238         export_code <list of constants (term syntax)> in SML
  4239     writing SML code to a file:
  4240         export_code <list of constants (term syntax)> in SML <filename>
  4241     writing OCaml code to a file:
  4242         export_code <list of constants (term syntax)> in OCaml <filename>
  4243     writing Haskell code to a bunch of files:
  4244         export_code <list of constants (term syntax)> in Haskell <filename>
  4245 
  4246     evaluating closed propositions to True/False using code generation:
  4247         method ``eval''
  4248 
  4249 Reasonable default setup of framework in HOL.
  4250 
  4251 Theorem attributs for selecting and transforming function equations theorems:
  4252 
  4253     [code fun]:        select a theorem as function equation for a specific constant
  4254     [code fun del]:    deselect a theorem as function equation for a specific constant
  4255     [code inline]:     select an equation theorem for unfolding (inlining) in place
  4256     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  4257 
  4258 User-defined serializations (target in {SML, OCaml, Haskell}):
  4259 
  4260     code_const <and-list of constants (term syntax)>
  4261       {(target) <and-list of const target syntax>}+
  4262 
  4263     code_type <and-list of type constructors>
  4264       {(target) <and-list of type target syntax>}+
  4265 
  4266     code_instance <and-list of instances>
  4267       {(target)}+
  4268         where instance ::= <type constructor> :: <class>
  4269 
  4270     code_class <and_list of classes>
  4271       {(target) <and-list of class target syntax>}+
  4272         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  4273 
  4274 code_instance and code_class only are effective to target Haskell.
  4275 
  4276 For example usage see src/HOL/ex/Codegenerator.thy and
  4277 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  4278 generation from Isabelle/HOL theories is available via "isatool doc
  4279 codegen".
  4280 
  4281 * Code generator: consts in 'consts_code' Isar commands are now
  4282 referred to by usual term syntax (including optional type
  4283 annotations).
  4284 
  4285 * Command 'no_translations' removes translation rules from theory
  4286 syntax.
  4287 
  4288 * Overloaded definitions are now actually checked for acyclic
  4289 dependencies.  The overloading scheme is slightly more general than
  4290 that of Haskell98, although Isabelle does not demand an exact
  4291 correspondence to type class and instance declarations.
  4292 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4293 exotic versions of overloading -- at the discretion of the user!
  4294 
  4295 Polymorphic constants are represented via type arguments, i.e. the
  4296 instantiation that matches an instance against the most general
  4297 declaration given in the signature.  For example, with the declaration
  4298 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4299 as c(nat).  Overloading is essentially simultaneous structural
  4300 recursion over such type arguments.  Incomplete specification patterns
  4301 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4302 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4303 Command 'print_theory' outputs the normalized system of recursive
  4304 equations, see section "definitions".
  4305 
  4306 * Configuration options are maintained within the theory or proof
  4307 context (with name and type bool/int/string), providing a very simple
  4308 interface to a poor-man's version of general context data.  Tools may
  4309 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4310 these values using Config.get etc.  Users may change options via an
  4311 associated attribute of the same name.  This form of context
  4312 declaration works particularly well with commands 'declare' or
  4313 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4314 very easy to avoid global references, which would not observe Isar
  4315 toplevel undo/redo and fail to work with multithreading.
  4316 
  4317 Various global ML references of Pure and HOL have been turned into
  4318 configuration options:
  4319 
  4320   Unify.search_bound		unify_search_bound
  4321   Unify.trace_bound		unify_trace_bound
  4322   Unify.trace_simp		unify_trace_simp
  4323   Unify.trace_types		unify_trace_types
  4324   Simplifier.simp_depth_limit	simp_depth_limit
  4325   Blast.depth_limit		blast_depth_limit
  4326   DatatypeProp.dtK		datatype_distinctness_limit
  4327   fast_arith_neq_limit  	fast_arith_neq_limit
  4328   fast_arith_split_limit	fast_arith_split_limit
  4329 
  4330 * Named collections of theorems may be easily installed as context
  4331 data using the functor NamedThmsFun (see also
  4332 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4333 attributes; there is also a toplevel print command.  This facility is
  4334 just a common case of general context data, which is the preferred way
  4335 for anything more complex than just a list of facts in canonical
  4336 order.
  4337 
  4338 * Isar: command 'declaration' augments a local theory by generic
  4339 declaration functions written in ML.  This enables arbitrary content
  4340 being added to the context, depending on a morphism that tells the
  4341 difference of the original declaration context wrt. the application
  4342 context encountered later on.
  4343 
  4344 * Isar: proper interfaces for simplification procedures.  Command
  4345 'simproc_setup' declares named simprocs (with match patterns, and body
  4346 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4347 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4348 
  4349 * Isar: an extra pair of brackets around attribute declarations
  4350 abbreviates a theorem reference involving an internal dummy fact,
  4351 which will be ignored later --- only the effect of the attribute on
  4352 the background context will persist.  This form of in-place
  4353 declarations is particularly useful with commands like 'declare' and
  4354 'using', for example ``have A using [[simproc a]] by simp''.
  4355 
  4356 * Isar: method "assumption" (and implicit closing of subproofs) now
  4357 takes simple non-atomic goal assumptions into account: after applying
  4358 an assumption as a rule the resulting subgoals are solved by atomic
  4359 assumption steps.  This is particularly useful to finish 'obtain'
  4360 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4361 without referring to the original premise "!!x. P x ==> thesis" in the
  4362 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4363 more permissive.
  4364 
  4365 * Isar: implicit use of prems from the Isar proof context is
  4366 considered a legacy feature.  Common applications like ``have A .''
  4367 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4368 referencing facts explicitly here improves readability and
  4369 maintainability of proof texts.
  4370 
  4371 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4372 the obtained context from the course of reasoning!  For example:
  4373 
  4374   assume "EX x y. A x & B y"   -- "any previous fact"
  4375   then guess x and y by clarify
  4376 
  4377 This technique is potentially adventurous, depending on the facts and
  4378 proof tools being involved here.
  4379 
  4380 * Isar: known facts from the proof context may be specified as literal
  4381 propositions, using ASCII back-quote syntax.  This works wherever
  4382 named facts used to be allowed so far, in proof commands, proof
  4383 methods, attributes etc.  Literal facts are retrieved from the context
  4384 according to unification of type and term parameters.  For example,
  4385 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4386 theorems in the current context, then these are valid literal facts:
  4387 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4388 
  4389 There is also a proof method "fact" which does the same composition
  4390 for explicit goal states, e.g. the following proof texts coincide with
  4391 certain special cases of literal facts:
  4392 
  4393   have "A" by fact                 ==  note `A`
  4394   have "A ==> B" by fact           ==  note `A ==> B`
  4395   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4396   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4397 
  4398 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4399 outer syntax.  Thus symbolic identifiers may be used without
  4400 additional white space in declarations like this: ``assume *: A''.
  4401 
  4402 * Isar: 'print_facts' prints all local facts of the current context,
  4403 both named and unnamed ones.
  4404 
  4405 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4406 
  4407   def x == "t" and y == "u"
  4408 
  4409 * Isar: added command 'unfolding', which is structurally similar to
  4410 'using', but affects both the goal state and facts by unfolding given
  4411 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4412 'unfolded' attribute may be replaced by first-class proof text.
  4413 
  4414 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4415 and command 'unfolding' now all support object-level equalities
  4416 (potentially conditional).  The underlying notion of rewrite rule is
  4417 analogous to the 'rule_format' attribute, but *not* that of the
  4418 Simplifier (which is usually more generous).
  4419 
  4420 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4421 premises of a theorem by n. Useful in conjunction with drule.
  4422 
  4423 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4424 method expression within a sandbox consisting of the first N
  4425 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4426 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4427 simplifies all new goals that emerge from applying rule foo to the
  4428 originally first one.
  4429 
  4430 * Isar: schematic goals are no longer restricted to higher-order
  4431 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  4432 expected.
  4433 
  4434 * Isar: the conclusion of a long theorem statement is now either
  4435 'shows' (a simultaneous conjunction, as before), or 'obtains'
  4436 (essentially a disjunction of cases with local parameters and
  4437 assumptions).  The latter allows to express general elimination rules
  4438 adequately; in this notation common elimination rules look like this:
  4439 
  4440   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  4441     assumes "EX x. P x"
  4442     obtains x where "P x"
  4443 
  4444   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  4445     assumes "A & B"
  4446     obtains A and B
  4447 
  4448   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  4449     assumes "A | B"
  4450     obtains
  4451       A
  4452     | B
  4453 
  4454 The subsequent classical rules even refer to the formal "thesis"
  4455 explicitly:
  4456 
  4457   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  4458     obtains "~ thesis"
  4459 
  4460   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  4461     obtains "thesis ==> something"
  4462 
  4463 The actual proof of an 'obtains' statement is analogous to that of the
  4464 Isar proof element 'obtain', only that there may be several cases.
  4465 Optional case names may be specified in parentheses; these will be
  4466 available both in the present proof and as annotations in the
  4467 resulting rule, for later use with the 'cases' method (cf. attribute
  4468 case_names).
  4469 
  4470 * Isar: the assumptions of a long theorem statement are available as
  4471 "assms" fact in the proof context.  This is more appropriate than the
  4472 (historical) "prems", which refers to all assumptions of the current
  4473 context, including those from the target locale, proof body etc.
  4474 
  4475 * Isar: 'print_statement' prints theorems from the current theory or
  4476 proof context in long statement form, according to the syntax of a
  4477 top-level lemma.
  4478 
  4479 * Isar: 'obtain' takes an optional case name for the local context
  4480 introduction rule (default "that").
  4481 
  4482 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  4483 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  4484 to occur.
  4485 
  4486 * Pure: syntax "CONST name" produces a fully internalized constant
  4487 according to the current context.  This is particularly useful for
  4488 syntax translations that should refer to internal constant
  4489 representations independently of name spaces.
  4490 
  4491 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  4492 instead of "FOO ". This allows multiple binder declarations to coexist
  4493 in the same context.  INCOMPATIBILITY.
  4494 
  4495 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  4496 primitive that also works in a locale context (both for constants and
  4497 fixed variables). Type declaration and internal syntactic representation
  4498 of given constants retrieved from the context. Likewise, the
  4499 'no_notation' command allows to remove given syntax annotations from the
  4500 current context.
  4501 
  4502 * Isar/locales: new derived specification elements 'axiomatization',
  4503 'definition', 'abbreviation', which support type-inference, admit
  4504 object-level specifications (equality, equivalence).  See also the
  4505 isar-ref manual.  Examples:
  4506 
  4507   axiomatization
  4508     eq  (infix "===" 50) where
  4509     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  4510 
  4511   definition "f x y = x + y + 1"
  4512   definition g where "g x = f x x"
  4513 
  4514   abbreviation
  4515     neq  (infix "=!=" 50) where
  4516     "x =!= y == ~ (x === y)"
  4517 
  4518 These specifications may be also used in a locale context.  Then the
  4519 constants being introduced depend on certain fixed parameters, and the
  4520 constant name is qualified by the locale base name.  An internal
  4521 abbreviation takes care for convenient input and output, making the
  4522 parameters implicit and using the original short name.  See also
  4523 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  4524 entities from a monomorphic theory.
  4525 
  4526 Presently, abbreviations are only available 'in' a target locale, but
  4527 not inherited by general import expressions.  Also note that
  4528 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  4529 'translations' in common applications.  The "no_abbrevs" print mode
  4530 prevents folding of abbreviations in term output.
  4531 
  4532 Concrete syntax is attached to specified constants in internal form,
  4533 independently of name spaces.  The parse tree representation is
  4534 slightly different -- use 'notation' instead of raw 'syntax', and
  4535 'translations' with explicit "CONST" markup to accommodate this.
  4536 
  4537 * Pure/Isar: unified syntax for new-style specification mechanisms
  4538 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  4539 full type inference and dummy patterns ("_").  For example:
  4540 
  4541   definition "K x _ = x"
  4542 
  4543   inductive conj for A B
  4544   where "A ==> B ==> conj A B"
  4545 
  4546 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  4547 the current context.  Print mode "no_abbrevs" prevents inversion of
  4548 abbreviations on output.
  4549 
  4550 * Isar/locales: improved parameter handling: use of locales "var" and
  4551 "struct" no longer necessary; - parameter renamings are no longer
  4552 required to be injective.  For example, this allows to define
  4553 endomorphisms as locale endom = homom mult mult h.
  4554 
  4555 * Isar/locales: changed the way locales with predicates are defined.
  4556 Instead of accumulating the specification, the imported expression is
  4557 now an interpretation.  INCOMPATIBILITY: different normal form of
  4558 locale expressions.  In particular, in interpretations of locales with
  4559 predicates, goals repesenting already interpreted fragments are not
  4560 removed automatically.  Use methods `intro_locales' and
  4561 `unfold_locales'; see below.
  4562 
  4563 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  4564 provide backward reasoning on locales predicates.  The methods are
  4565 aware of interpretations and discharge corresponding goals.
  4566 `intro_locales' is less aggressive then `unfold_locales' and does not
  4567 unfold predicates to assumptions.
  4568 
  4569 * Isar/locales: the order in which locale fragments are accumulated
  4570 has changed.  This enables to override declarations from fragments due
  4571 to interpretations -- for example, unwanted simp rules.
  4572 
  4573 * Isar/locales: interpretation in theories and proof contexts has been
  4574 extended.  One may now specify (and prove) equations, which are
  4575 unfolded in interpreted theorems.  This is useful for replacing
  4576 defined concepts (constants depending on locale parameters) by
  4577 concepts already existing in the target context.  Example:
  4578 
  4579   interpretation partial_order ["op <= :: [int, int] => bool"]
  4580     where "partial_order.less (op <=) (x::int) y = (x < y)"
  4581 
  4582 Typically, the constant `partial_order.less' is created by a
  4583 definition specification element in the context of locale
  4584 partial_order.
  4585 
  4586 * Method "induct": improved internal context management to support
  4587 local fixes and defines on-the-fly. Thus explicit meta-level
  4588 connectives !!  and ==> are rarely required anymore in inductive goals
  4589 (using object-logic connectives for this purpose has been long
  4590 obsolete anyway). Common proof patterns are explained in
  4591 src/HOL/Induct/Common_Patterns.thy, see also
  4592 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  4593 examples.
  4594 
  4595 * Method "induct": improved handling of simultaneous goals. Instead of
  4596 introducing object-level conjunction, the statement is now split into
  4597 several conclusions, while the corresponding symbolic cases are nested
  4598 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  4599 see src/HOL/Induct/Common_Patterns.thy, for example.
  4600 
  4601 * Method "induct": mutual induction rules are now specified as a list
  4602 of rule sharing the same induction cases. HOL packages usually provide
  4603 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  4604 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  4605 mutual induction rules differently, i.e. like this:
  4606 
  4607   (induct rule: foo_bar.inducts)
  4608   (induct set: foo bar)
  4609   (induct pred: foo bar)
  4610   (induct type: foo bar)
  4611 
  4612 The ML function ProjectRule.projections turns old-style rules into the
  4613 new format.
  4614 
  4615 * Method "coinduct": dual of induction, see
  4616 src/HOL/Library/Coinductive_List.thy for various examples.
  4617 
  4618 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  4619 considered a legacy feature.
  4620 
  4621 * Attribute "symmetric" produces result with standardized schematic
  4622 variables (index 0).  Potential INCOMPATIBILITY.
  4623 
  4624 * Simplifier: by default the simplifier trace only shows top level
  4625 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  4626 default. Thus there is less danger of being flooded by the trace. The
  4627 trace indicates where parts have been suppressed.
  4628   
  4629 * Provers/classical: removed obsolete classical version of elim_format
  4630 attribute; classical elim/dest rules are now treated uniformly when
  4631 manipulating the claset.
  4632 
  4633 * Provers/classical: stricter checks to ensure that supplied intro,
  4634 dest and elim rules are well-formed; dest and elim rules must have at
  4635 least one premise.
  4636 
  4637 * Provers/classical: attributes dest/elim/intro take an optional
  4638 weight argument for the rule (just as the Pure versions).  Weights are
  4639 ignored by automated tools, but determine the search order of single
  4640 rule steps.
  4641 
  4642 * Syntax: input syntax now supports dummy variable binding "%_. b",
  4643 where the body does not mention the bound variable.  Note that dummy
  4644 patterns implicitly depend on their context of bounds, which makes
  4645 "{_. _}" match any set comprehension as expected.  Potential
  4646 INCOMPATIBILITY -- parse translations need to cope with syntactic
  4647 constant "_idtdummy" in the binding position.
  4648 
  4649 * Syntax: removed obsolete syntactic constant "_K" and its associated
  4650 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  4651 for example "A -> B" => "Pi A (%_. B)".
  4652 
  4653 * Pure: 'class_deps' command visualizes the subclass relation, using
  4654 the graph browser tool.
  4655 
  4656 * Pure: 'print_theory' now suppresses certain internal declarations by
  4657 default; use '!' option for full details.
  4658 
  4659 
  4660 *** HOL ***
  4661 
  4662 * Method "metis" proves goals by applying the Metis general-purpose
  4663 resolution prover (see also http://gilith.com/software/metis/).
  4664 Examples are in the directory MetisExamples.  WARNING: the
  4665 Isabelle/HOL-Metis integration does not yet work properly with
  4666 multi-threading.
  4667   
  4668 * Command 'sledgehammer' invokes external automatic theorem provers as
  4669 background processes.  It generates calls to the "metis" method if
  4670 successful. These can be pasted into the proof.  Users do not have to
  4671 wait for the automatic provers to return.  WARNING: does not really
  4672 work with multi-threading.
  4673 
  4674 * New "auto_quickcheck" feature tests outermost goal statements for
  4675 potential counter-examples.  Controlled by ML references
  4676 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  4677 5000 milliseconds).  Fails silently if statements is outside of
  4678 executable fragment, or any other codgenerator problem occurs.
  4679 
  4680 * New constant "undefined" with axiom "undefined x = undefined".
  4681 
  4682 * Added class "HOL.eq", allowing for code generation with polymorphic
  4683 equality.
  4684 
  4685 * Some renaming of class constants due to canonical name prefixing in
  4686 the new 'class' package:
  4687 
  4688     HOL.abs ~> HOL.abs_class.abs
  4689     HOL.divide ~> HOL.divide_class.divide
  4690     0 ~> HOL.zero_class.zero
  4691     1 ~> HOL.one_class.one
  4692     op + ~> HOL.plus_class.plus
  4693     op - ~> HOL.minus_class.minus
  4694     uminus ~> HOL.minus_class.uminus
  4695     op * ~> HOL.times_class.times
  4696     op < ~> HOL.ord_class.less
  4697     op <= > HOL.ord_class.less_eq
  4698     Nat.power ~> Power.power_class.power
  4699     Nat.size ~> Nat.size_class.size
  4700     Numeral.number_of ~> Numeral.number_class.number_of
  4701     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  4702     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  4703     Orderings.min ~> Orderings.ord_class.min
  4704     Orderings.max ~> Orderings.ord_class.max
  4705     Divides.op div ~> Divides.div_class.div
  4706     Divides.op mod ~> Divides.div_class.mod
  4707     Divides.op dvd ~> Divides.div_class.dvd
  4708 
  4709 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  4710 
  4711 a) User-defined constants using any of the names "plus", "minus",
  4712 "times", "less" or "less_eq". The standard syntax translations for
  4713 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  4714 names.
  4715 
  4716 b) Variables named "plus", "minus", "times", "less", "less_eq"
  4717 INCOMPATIBILITY: use more specific names.
  4718 
  4719 c) Permutative equations (e.g. "a + b = b + a")
  4720 Since the change of names also changes the order of terms, permutative
  4721 rewrite rules may get applied in a different order. Experience shows
  4722 that this is rarely the case (only two adaptions in the whole Isabelle
  4723 distribution).  INCOMPATIBILITY: rewrite proofs
  4724 
  4725 d) ML code directly refering to constant names
  4726 This in general only affects hand-written proof tactics, simprocs and
  4727 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  4728 Consider using @{const_name} antiquotation.
  4729 
  4730 * New class "default" with associated constant "default".
  4731 
  4732 * Function "sgn" is now overloaded and available on int, real, complex
  4733 (and other numeric types), using class "sgn".  Two possible defs of
  4734 sgn are given as equational assumptions in the classes sgn_if and
  4735 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  4736 INCOMPATIBILITY.
  4737 
  4738 * Locale "partial_order" now unified with class "order" (cf. theory
  4739 Orderings), added parameter "less".  INCOMPATIBILITY.
  4740 
  4741 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  4742 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  4743 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  4744 
  4745 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  4746 changed order of proof goals in instance proofs.
  4747 
  4748 * The transitivity reasoner for partial and linear orders is set up
  4749 for classes "order" and "linorder".  Instances of the reasoner are available
  4750 in all contexts importing or interpreting the corresponding locales.
  4751 Method "order" invokes the reasoner separately; the reasoner
  4752 is also integrated with the Simplifier as a solver.  Diagnostic
  4753 command 'print_orders' shows the available instances of the reasoner
  4754 in the current context.
  4755 
  4756 * Localized monotonicity predicate in theory "Orderings"; integrated
  4757 lemmas max_of_mono and min_of_mono with this predicate.
  4758 INCOMPATIBILITY.
  4759 
  4760 * Formulation of theorem "dense" changed slightly due to integration
  4761 with new class dense_linear_order.
  4762 
  4763 * Uniform lattice theory development in HOL.
  4764 
  4765     constants "meet" and "join" now named "inf" and "sup"
  4766     constant "Meet" now named "Inf"
  4767 
  4768     classes "meet_semilorder" and "join_semilorder" now named
  4769       "lower_semilattice" and "upper_semilattice"
  4770     class "lorder" now named "lattice"
  4771     class "comp_lat" now named "complete_lattice"
  4772 
  4773     Instantiation of lattice classes allows explicit definitions
  4774     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  4775 
  4776   INCOMPATIBILITY.  Theorem renames:
  4777 
  4778     meet_left_le            ~> inf_le1
  4779     meet_right_le           ~> inf_le2
  4780     join_left_le            ~> sup_ge1
  4781     join_right_le           ~> sup_ge2
  4782     meet_join_le            ~> inf_sup_ord
  4783     le_meetI                ~> le_infI
  4784     join_leI                ~> le_supI
  4785     le_meet                 ~> le_inf_iff
  4786     le_join                 ~> ge_sup_conv
  4787     meet_idempotent         ~> inf_idem
  4788     join_idempotent         ~> sup_idem
  4789     meet_comm               ~> inf_commute
  4790     join_comm               ~> sup_commute
  4791     meet_leI1               ~> le_infI1
  4792     meet_leI2               ~> le_infI2
  4793     le_joinI1               ~> le_supI1
  4794     le_joinI2               ~> le_supI2
  4795     meet_assoc              ~> inf_assoc
  4796     join_assoc              ~> sup_assoc
  4797     meet_left_comm          ~> inf_left_commute
  4798     meet_left_idempotent    ~> inf_left_idem
  4799     join_left_comm          ~> sup_left_commute
  4800     join_left_idempotent    ~> sup_left_idem
  4801     meet_aci                ~> inf_aci
  4802     join_aci                ~> sup_aci
  4803     le_def_meet             ~> le_iff_inf
  4804     le_def_join             ~> le_iff_sup
  4805     join_absorp2            ~> sup_absorb2
  4806     join_absorp1            ~> sup_absorb1
  4807     meet_absorp1            ~> inf_absorb1
  4808     meet_absorp2            ~> inf_absorb2
  4809     meet_join_absorp        ~> inf_sup_absorb
  4810     join_meet_absorp        ~> sup_inf_absorb
  4811     distrib_join_le         ~> distrib_sup_le
  4812     distrib_meet_le         ~> distrib_inf_le
  4813 
  4814     add_meet_distrib_left   ~> add_inf_distrib_left
  4815     add_join_distrib_left   ~> add_sup_distrib_left
  4816     is_join_neg_meet        ~> is_join_neg_inf
  4817     is_meet_neg_join        ~> is_meet_neg_sup
  4818     add_meet_distrib_right  ~> add_inf_distrib_right
  4819     add_join_distrib_right  ~> add_sup_distrib_right
  4820     add_meet_join_distribs  ~> add_sup_inf_distribs
  4821     join_eq_neg_meet        ~> sup_eq_neg_inf
  4822     meet_eq_neg_join        ~> inf_eq_neg_sup
  4823     add_eq_meet_join        ~> add_eq_inf_sup
  4824     meet_0_imp_0            ~> inf_0_imp_0
  4825     join_0_imp_0            ~> sup_0_imp_0
  4826     meet_0_eq_0             ~> inf_0_eq_0
  4827     join_0_eq_0             ~> sup_0_eq_0
  4828     neg_meet_eq_join        ~> neg_inf_eq_sup
  4829     neg_join_eq_meet        ~> neg_sup_eq_inf
  4830     join_eq_if              ~> sup_eq_if
  4831 
  4832     mono_meet               ~> mono_inf
  4833     mono_join               ~> mono_sup
  4834     meet_bool_eq            ~> inf_bool_eq
  4835     join_bool_eq            ~> sup_bool_eq
  4836     meet_fun_eq             ~> inf_fun_eq
  4837     join_fun_eq             ~> sup_fun_eq
  4838     meet_set_eq             ~> inf_set_eq
  4839     join_set_eq             ~> sup_set_eq
  4840     meet1_iff               ~> inf1_iff
  4841     meet2_iff               ~> inf2_iff
  4842     meet1I                  ~> inf1I
  4843     meet2I                  ~> inf2I
  4844     meet1D1                 ~> inf1D1
  4845     meet2D1                 ~> inf2D1
  4846     meet1D2                 ~> inf1D2
  4847     meet2D2                 ~> inf2D2
  4848     meet1E                  ~> inf1E
  4849     meet2E                  ~> inf2E
  4850     join1_iff               ~> sup1_iff
  4851     join2_iff               ~> sup2_iff
  4852     join1I1                 ~> sup1I1
  4853     join2I1                 ~> sup2I1
  4854     join1I1                 ~> sup1I1
  4855     join2I2                 ~> sup1I2
  4856     join1CI                 ~> sup1CI
  4857     join2CI                 ~> sup2CI
  4858     join1E                  ~> sup1E
  4859     join2E                  ~> sup2E
  4860 
  4861     is_meet_Meet            ~> is_meet_Inf
  4862     Meet_bool_def           ~> Inf_bool_def
  4863     Meet_fun_def            ~> Inf_fun_def
  4864     Meet_greatest           ~> Inf_greatest
  4865     Meet_lower              ~> Inf_lower
  4866     Meet_set_def            ~> Inf_set_def
  4867 
  4868     Sup_def                 ~> Sup_Inf
  4869     Sup_bool_eq             ~> Sup_bool_def
  4870     Sup_fun_eq              ~> Sup_fun_def
  4871     Sup_set_eq              ~> Sup_set_def
  4872 
  4873     listsp_meetI            ~> listsp_infI
  4874     listsp_meet_eq          ~> listsp_inf_eq
  4875 
  4876     meet_min                ~> inf_min
  4877     join_max                ~> sup_max
  4878 
  4879 * Added syntactic class "size"; overloaded constant "size" now has
  4880 type "'a::size ==> bool"
  4881 
  4882 * Internal reorganisation of `size' of datatypes: size theorems
  4883 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4884 simplification rules by default!); theorems "prod.size" now named
  4885 "*.size".
  4886 
  4887 * Class "div" now inherits from class "times" rather than "type".
  4888 INCOMPATIBILITY.
  4889 
  4890 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4891 Linorder etc.  have disappeared; operations defined in terms of
  4892 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4893 
  4894 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4895 
  4896 * HOL-Word: New extensive library and type for generic, fixed size
  4897 machine words, with arithmetic, bit-wise, shifting and rotating
  4898 operations, reflection into int, nat, and bool lists, automation for
  4899 linear arithmetic (by automatic reflection into nat or int), including
  4900 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4901 arithmetic type classes, supporting automatic simplification of
  4902 numerals on all operations.
  4903 
  4904 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4905 
  4906 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4907 
  4908 * Code generator library theories:
  4909   - Code_Integer represents HOL integers by big integer literals in target
  4910     languages.
  4911   - Code_Char represents HOL characters by character literals in target
  4912     languages.
  4913   - Code_Char_chr like Code_Char, but also offers treatment of character
  4914     codes; includes Code_Integer.
  4915   - Executable_Set allows to generate code for finite sets using lists.
  4916   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4917     denominator).
  4918   - Executable_Real implements a subset of real numbers, namly those
  4919     representable by rational numbers.
  4920   - Efficient_Nat implements natural numbers by integers, which in general will
  4921     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4922     includes Code_Integer.
  4923   - Code_Index provides an additional datatype index which is mapped to
  4924     target-language built-in integers.
  4925   - Code_Message provides an additional datatype message_string which is isomorphic to
  4926     strings; messages are mapped to target-language strings.
  4927 
  4928 * New package for inductive predicates
  4929 
  4930   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4931 
  4932     inductive
  4933       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4934       for z_1 :: U_1 and ... and z_n :: U_m
  4935     where
  4936       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4937     | ...
  4938 
  4939   with full support for type-inference, rather than
  4940 
  4941     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4942 
  4943     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4944     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4945 
  4946     inductive "s z_1 ... z_m"
  4947     intros
  4948       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4949       ...
  4950 
  4951   For backward compatibility, there is a wrapper allowing inductive
  4952   sets to be defined with the new package via
  4953 
  4954     inductive_set
  4955       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4956       for z_1 :: U_1 and ... and z_n :: U_m
  4957     where
  4958       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4959     | ...
  4960 
  4961   or
  4962 
  4963     inductive_set
  4964       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4965       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4966       for z_1 :: U_1 and ... and z_n :: U_m
  4967     where
  4968       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4969     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4970     | ...
  4971 
  4972   if the additional syntax "p ..." is required.
  4973 
  4974   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4975   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4976 
  4977   INCOMPATIBILITIES:
  4978 
  4979   - Since declaration and definition of inductive sets or predicates
  4980     is no longer separated, abbreviations involving the newly
  4981     introduced sets or predicates must be specified together with the
  4982     introduction rules after the 'where' keyword (see above), rather
  4983     than before the actual inductive definition.
  4984 
  4985   - The variables in induction and elimination rules are now
  4986     quantified in the order of their occurrence in the introduction
  4987     rules, rather than in alphabetical order. Since this may break
  4988     some proofs, these proofs either have to be repaired, e.g. by
  4989     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4990     statements of the form
  4991 
  4992       case (rule_i a_i_1 ... a_i_{k_i})
  4993 
  4994     or the old order of quantification has to be restored by explicitly adding
  4995     meta-level quantifiers in the introduction rules, i.e.
  4996 
  4997       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4998 
  4999   - The format of the elimination rules is now
  5000 
  5001       p z_1 ... z_m x_1 ... x_n ==>
  5002         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5003         ==> ... ==> P
  5004 
  5005     for predicates and
  5006 
  5007       (x_1, ..., x_n) : s z_1 ... z_m ==>
  5008         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5009         ==> ... ==> P
  5010 
  5011     for sets rather than
  5012 
  5013       x : s z_1 ... z_m ==>
  5014         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  5015         ==> ... ==> P
  5016 
  5017     This may require terms in goals to be expanded to n-tuples
  5018     (e.g. using case_tac or simplification with the split_paired_all
  5019     rule) before the above elimination rule is applicable.
  5020 
  5021   - The elimination or case analysis rules for (mutually) inductive
  5022     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  5023     list of rules "p_1_..._p_k.elims" is no longer available.
  5024 
  5025 * New package "function"/"fun" for general recursive functions,
  5026 supporting mutual and nested recursion, definitions in local contexts,
  5027 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  5028 for small examples, and the separate tutorial on the function
  5029 package. The old recdef "package" is still available as before, but
  5030 users are encouraged to use the new package.
  5031 
  5032 * Method "lexicographic_order" automatically synthesizes termination
  5033 relations as lexicographic combinations of size measures. 
  5034 
  5035 * Case-expressions allow arbitrary constructor-patterns (including
  5036 "_") and take their order into account, like in functional
  5037 programming.  Internally, this is translated into nested
  5038 case-expressions; missing cases are added and mapped to the predefined
  5039 constant "undefined". In complicated cases printing may no longer show
  5040 the original input but the internal form. Lambda-abstractions allow
  5041 the same form of pattern matching: "% pat1 => e1 | ..." is an
  5042 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  5043 variable.
  5044 
  5045 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  5046 is an abbreviation for "of_nat :: nat => int". The simplification
  5047 rules for "of_nat" have been changed to work like "int" did
  5048 previously.  Potential INCOMPATIBILITY:
  5049   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  5050   - of_nat_diff and of_nat_mult are no longer default simp rules
  5051 
  5052 * Method "algebra" solves polynomial equations over (semi)rings using
  5053 Groebner bases. The (semi)ring structure is defined by locales and the
  5054 tool setup depends on that generic context. Installing the method for
  5055 a specific type involves instantiating the locale and possibly adding
  5056 declarations for computation on the coefficients.  The method is
  5057 already instantiated for natural numbers and for the axiomatic class
  5058 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  5059 CALCULEMUS 2007 for the general principles underlying this
  5060 architecture of context-aware proof-tools.
  5061 
  5062 * Method "ferrack" implements quantifier elimination over
  5063 special-purpose dense linear orders using locales (analogous to
  5064 "algebra"). The method is already installed for class
  5065 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  5066 rat, etc.
  5067 
  5068 * Former constant "List.op @" now named "List.append".  Use ML
  5069 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  5070 circumvent possible incompatibilities when working on ML level.
  5071 
  5072 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  5073 
  5074 * New function listsum :: 'a list => 'a for arbitrary monoids.
  5075 Special syntax: "SUM x <- xs. f x" (and latex variants)
  5076 
  5077 * New syntax for Haskell-like list comprehension (input only), eg.
  5078 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  5079 
  5080 * The special syntax for function "filter" has changed from [x :
  5081 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  5082 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  5083 
  5084 * [a..b] is now defined for arbitrary linear orders.  It used to be
  5085 defined on nat only, as an abbreviation for [a..<Suc b]
  5086 INCOMPATIBILITY.
  5087 
  5088 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  5089 
  5090 * New functions "sorted" and "sort" in src/HOL/List.thy.
  5091 
  5092 * New lemma collection field_simps (an extension of ring_simps) for
  5093 manipulating (in)equations involving division. Multiplies with all
  5094 denominators that can be proved to be non-zero (in equations) or
  5095 positive/negative (in inequations).
  5096 
  5097 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  5098 have been improved and renamed to ring_simps, group_simps and
  5099 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  5100 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  5101 
  5102 * Theory Library/Commutative_Ring: switched from recdef to function
  5103 package; constants add, mul, pow now curried.  Infix syntax for
  5104 algebraic operations.
  5105 
  5106 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  5107 INCOMPATIBILITY.
  5108 
  5109 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  5110 INCOMPATIBILITY.
  5111 
  5112 * HOL/records: generalised field-update to take a function on the
  5113 field rather than the new value: r(|A := x|) is translated to A_update
  5114 (K x) r The K-combinator that is internally used is called K_record.
  5115 INCOMPATIBILITY: Usage of the plain update functions has to be
  5116 adapted.
  5117  
  5118 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  5119 * x = 0, which are required for a semiring.  Richer structures do not
  5120 inherit from semiring_0 anymore, because this property is a theorem
  5121 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  5122 there is more to prove, but this is mostly trivial.
  5123 
  5124 * Class "recpower" is generalized to arbitrary monoids, not just
  5125 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  5126 commutativity or semiring properties additionally.
  5127 
  5128 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  5129 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  5130 better use 'abbreviation'.
  5131 
  5132 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  5133 
  5134 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  5135 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  5136 significant changes for setting up numeral syntax for types:
  5137   - New constants Numeral.pred and Numeral.succ instead
  5138       of former Numeral.bin_pred and Numeral.bin_succ.
  5139   - Use integer operations instead of bin_add, bin_mult and so on.
  5140   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  5141   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  5142 
  5143 See src/HOL/Integ/IntArith.thy for an example setup.
  5144 
  5145 * Command 'normal_form' computes the normal form of a term that may
  5146 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  5147 produces ``[b, c, a]'' (without proof).  This command is suitable for
  5148 heavy-duty computations because the functions are compiled to ML
  5149 first.  Correspondingly, a method "normalization" is provided.  See
  5150 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  5151 
  5152 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  5153 25 like -->); output depends on the "iff" print_mode, the default is
  5154 "A = B" (with priority 50).
  5155 
  5156 * Relations less (<) and less_eq (<=) are also available on type bool.
  5157 Modified syntax to disallow nesting without explicit parentheses,
  5158 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  5159 INCOMPATIBILITY.
  5160 
  5161 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  5162 
  5163 * Relation composition operator "op O" now has precedence 75 and binds
  5164 stronger than union and intersection. INCOMPATIBILITY.
  5165 
  5166 * The old set interval syntax "{m..n(}" (and relatives) has been
  5167 removed.  Use "{m..<n}" (and relatives) instead.
  5168 
  5169 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  5170 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  5171 ``declare [[simproc del: neq]]''.
  5172 
  5173 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  5174 True/False.
  5175 
  5176 * Theorem Cons_eq_map_conv no longer declared as "simp".
  5177 
  5178 * Theorem setsum_mult renamed to setsum_right_distrib.
  5179 
  5180 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  5181 ``rule'' method.
  5182 
  5183 * Reimplemented methods "sat" and "satx", with several improvements:
  5184 goals no longer need to be stated as "<prems> ==> False", equivalences
  5185 (i.e. "=" on type bool) are handled, variable names of the form
  5186 "lit_<n>" are no longer reserved, significant speedup.
  5187 
  5188 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  5189 zChaff is still supported as well.
  5190 
  5191 * 'inductive' and 'datatype': provide projections of mutual rules,
  5192 bundled as foo_bar.inducts;
  5193 
  5194 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  5195 Library.
  5196 
  5197 * Library: moved theory Accessible_Part to main HOL.
  5198 
  5199 * Library: added theory Coinductive_List of potentially infinite lists
  5200 as greatest fixed-point.
  5201 
  5202 * Library: added theory AssocList which implements (finite) maps as
  5203 association lists.
  5204 
  5205 * Method "evaluation" solves goals (i.e. a boolean expression)
  5206 efficiently by compiling it to ML.  The goal is "proved" (via an
  5207 oracle) if it evaluates to True.
  5208 
  5209 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  5210 also when invoked by the simplifier.  This results in the Simplifier
  5211 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  5212 Configuration option fast_arith_split_limit=0 recovers the old
  5213 behavior.
  5214 
  5215 * Support for hex (0x20) and binary (0b1001) numerals.
  5216 
  5217 * New method: reify eqs (t), where eqs are equations for an
  5218 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  5219 parameter, computes a term s::'b and a list xs::'a list and proves the
  5220 theorem I xs s = t. This is also known as reification or quoting. The
  5221 resulting theorem is applied to the subgoal to substitute t with I xs
  5222 s.  If t is omitted, the subgoal itself is reified.
  5223 
  5224 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  5225 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  5226 where f is supposed to be a computable function (in the sense of code
  5227 generattion). The method uses reify to compute s and xs as above then
  5228 applies corr_thm and uses normalization by evaluation to "prove" f s =
  5229 r and finally gets the theorem t = r, which is again applied to the
  5230 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  5231 
  5232 * Reflection: Automatic reification now handels binding, an example is
  5233 available in src/HOL/ex/ReflectionEx.thy
  5234 
  5235 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  5236 command 'statespace' that is similar to 'record', but introduces an
  5237 abstract specification based on the locale infrastructure instead of
  5238 HOL types.  This leads to extra flexibility in composing state spaces,
  5239 in particular multiple inheritance and renaming of components.
  5240 
  5241 
  5242 *** HOL-Complex ***
  5243 
  5244 * Hyperreal: Functions root and sqrt are now defined on negative real
  5245 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  5246 Nonnegativity side conditions have been removed from many lemmas, so
  5247 that more subgoals may now be solved by simplification; potential
  5248 INCOMPATIBILITY.
  5249 
  5250 * Real: new type classes formalize real normed vector spaces and
  5251 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  5252 and norm :: 'a => real.
  5253 
  5254 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  5255 reals into other types. The overloaded constant Reals :: 'a set is now
  5256 defined as range of_real; potential INCOMPATIBILITY.
  5257 
  5258 * Real: proper support for ML code generation, including 'quickcheck'.
  5259 Reals are implemented as arbitrary precision rationals.
  5260 
  5261 * Hyperreal: Several constants that previously worked only for the
  5262 reals have been generalized, so they now work over arbitrary vector
  5263 spaces. Type annotations may need to be added in some cases; potential
  5264 INCOMPATIBILITY.
  5265 
  5266   Infinitesimal  :: ('a::real_normed_vector) star set
  5267   HFinite        :: ('a::real_normed_vector) star set
  5268   HInfinite      :: ('a::real_normed_vector) star set
  5269   approx         :: ('a::real_normed_vector) star => 'a star => bool
  5270   monad          :: ('a::real_normed_vector) star => 'a star set
  5271   galaxy         :: ('a::real_normed_vector) star => 'a star set
  5272   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  5273   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  5274   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  5275   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  5276   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  5277   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  5278   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5279   sgn            :: 'a::real_normed_vector => 'a
  5280   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5281 
  5282 * Complex: Some complex-specific constants are now abbreviations for
  5283 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5284 hnorm.  Other constants have been entirely removed in favor of the
  5285 polymorphic versions (INCOMPATIBILITY):
  5286 
  5287   approx        <-- capprox
  5288   HFinite       <-- CFinite
  5289   HInfinite     <-- CInfinite
  5290   Infinitesimal <-- CInfinitesimal
  5291   monad         <-- cmonad
  5292   galaxy        <-- cgalaxy
  5293   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5294   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5295   (ns)deriv     <-- (ns)cderiv
  5296 
  5297 
  5298 *** HOL-Algebra ***
  5299 
  5300 * Formalisation of ideals and the quotient construction over rings.
  5301 
  5302 * Order and lattice theory no longer based on records.
  5303 INCOMPATIBILITY.
  5304 
  5305 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5306 greatest_closed.  INCOMPATIBILITY.
  5307 
  5308 * Method algebra is now set up via an attribute.  For examples see
  5309 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5310 of algebraic structures.
  5311 
  5312 * Renamed theory CRing to Ring.
  5313 
  5314 
  5315 *** HOL-Nominal ***
  5316 
  5317 * Substantial, yet incomplete support for nominal datatypes (binding
  5318 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5319 src/HOL/Nominal/Examples.  Prospective users should consult
  5320 http://isabelle.in.tum.de/nominal/
  5321 
  5322 
  5323 *** ML ***
  5324 
  5325 * ML basics: just one true type int, which coincides with IntInf.int
  5326 (even on SML/NJ).
  5327 
  5328 * ML within Isar: antiquotations allow to embed statically-checked
  5329 formal entities in the source, referring to the context available at
  5330 compile-time.  For example:
  5331 
  5332 ML {* @{sort "{zero,one}"} *}
  5333 ML {* @{typ "'a => 'b"} *}
  5334 ML {* @{term "%x. x"} *}
  5335 ML {* @{prop "x == y"} *}
  5336 ML {* @{ctyp "'a => 'b"} *}
  5337 ML {* @{cterm "%x. x"} *}
  5338 ML {* @{cprop "x == y"} *}
  5339 ML {* @{thm asm_rl} *}
  5340 ML {* @{thms asm_rl} *}
  5341 ML {* @{type_name c} *}
  5342 ML {* @{type_syntax c} *}
  5343 ML {* @{const_name c} *}
  5344 ML {* @{const_syntax c} *}
  5345 ML {* @{context} *}
  5346 ML {* @{theory} *}
  5347 ML {* @{theory Pure} *}
  5348 ML {* @{theory_ref} *}
  5349 ML {* @{theory_ref Pure} *}
  5350 ML {* @{simpset} *}
  5351 ML {* @{claset} *}
  5352 ML {* @{clasimpset} *}
  5353 
  5354 The same works for sources being ``used'' within an Isar context.
  5355 
  5356 * ML in Isar: improved error reporting; extra verbosity with
  5357 ML_Context.trace enabled.
  5358 
  5359 * Pure/General/table.ML: the join operations now works via exceptions
  5360 DUP/SAME instead of type option. This is simpler in simple cases, and
  5361 admits slightly more efficient complex applications.
  5362 
  5363 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5364 use Context.generic instead of just theory.
  5365 
  5366 * Pure: datatype Context.generic joins theory/Proof.context and
  5367 provides some facilities for code that works in either kind of
  5368 context, notably GenericDataFun for uniform theory and proof data.
  5369 
  5370 * Pure: simplified internal attribute type, which is now always
  5371 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5372 local (Proof.context) attributes have been discontinued, while
  5373 minimizing code duplication. Thm.rule_attribute and
  5374 Thm.declaration_attribute build canonical attributes; see also structure
  5375 Context for further operations on Context.generic, notably
  5376 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5377 declarations and definitions.
  5378 
  5379 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5380 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5381 init only required for impure data. INCOMPATIBILITY: empty really need
  5382 to be empty (no dependencies on theory content!)
  5383 
  5384 * Pure/kernel: consts certification ignores sort constraints given in
  5385 signature declarations. (This information is not relevant to the
  5386 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5387 potential INCOMPATIBILITY.
  5388 
  5389 * Pure: axiomatic type classes are now purely definitional, with
  5390 explicit proofs of class axioms and super class relations performed
  5391 internally. See Pure/axclass.ML for the main internal interfaces --
  5392 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5393 AxClass.axiomatize_class/classrel/arity supersede
  5394 Sign.add_classes/classrel/arities.
  5395 
  5396 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5397 global/local versions on theory vs. Proof.context have been
  5398 discontinued; Attrib.syntax and Method.syntax have been adapted
  5399 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5400 attributes, methods, etc.
  5401 
  5402 * Pure: several functions of signature "... -> theory -> theory * ..."
  5403 have been reoriented to "... -> theory -> ... * theory" in order to
  5404 allow natural usage in combination with the ||>, ||>>, |-> and
  5405 fold_map combinators.
  5406 
  5407 * Pure: official theorem names (closed derivations) and additional
  5408 comments (tags) are now strictly separate.  Name hints -- which are
  5409 maintained as tags -- may be attached any time without affecting the
  5410 derivation.
  5411 
  5412 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5413 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5414 achieve the old behaviour.
  5415 
  5416 * Pure: the "Goal" constant is now called "prop", supporting a
  5417 slightly more general idea of ``protecting'' meta-level rule
  5418 statements.
  5419 
  5420 * Pure: Logic.(un)varify only works in a global context, which is now
  5421 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5422 Logic.legacy_(un)varify as temporary workaround.
  5423 
  5424 * Pure: structure Name provides scalable operations for generating
  5425 internal variable names, notably Name.variants etc.  This replaces
  5426 some popular functions from term.ML:
  5427 
  5428   Term.variant		->  Name.variant
  5429   Term.variantlist	->  Name.variant_list
  5430   Term.invent_names	->  Name.invent_list
  5431 
  5432 Note that low-level renaming rarely occurs in new code -- operations
  5433 from structure Variable are used instead (see below).
  5434 
  5435 * Pure: structure Variable provides fundamental operations for proper
  5436 treatment of fixed/schematic variables in a context.  For example,
  5437 Variable.import introduces fixes for schematics of given facts and
  5438 Variable.export reverses the effect (up to renaming) -- this replaces
  5439 various freeze_thaw operations.
  5440 
  5441 * Pure: structure Goal provides simple interfaces for
  5442 init/conclude/finish and tactical prove operations (replacing former
  5443 Tactic.prove).  Goal.prove is the canonical way to prove results
  5444 within a given context; Goal.prove_global is a degraded version for
  5445 theory level goals, including a global Drule.standard.  Note that
  5446 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  5447 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  5448 in a locale context).
  5449 
  5450 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  5451 and type checking (Syntax.check_term etc.), with common combinations
  5452 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  5453 which are considered legacy and await removal.
  5454 
  5455 * Pure/Syntax: generic interfaces for type unchecking
  5456 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  5457 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  5458 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  5459 available for convenience, but refer to the very same operations using
  5460 a mere theory instead of a full context.
  5461 
  5462 * Isar: simplified treatment of user-level errors, using exception
  5463 ERROR of string uniformly.  Function error now merely raises ERROR,
  5464 without any side effect on output channels.  The Isar toplevel takes
  5465 care of proper display of ERROR exceptions.  ML code may use plain
  5466 handle/can/try; cat_error may be used to concatenate errors like this:
  5467 
  5468   ... handle ERROR msg => cat_error msg "..."
  5469 
  5470 Toplevel ML code (run directly or through the Isar toplevel) may be
  5471 embedded into the Isar toplevel with exception display/debug like
  5472 this:
  5473 
  5474   Isar.toplevel (fn () => ...)
  5475 
  5476 INCOMPATIBILITY, removed special transform_error facilities, removed
  5477 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  5478 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  5479 -- use plain ERROR instead.
  5480 
  5481 * Isar: theory setup now has type (theory -> theory), instead of a
  5482 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  5483 
  5484 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  5485 ProofContext.debug/verbose flags.
  5486 
  5487 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  5488 theory before entering a proof state.  Transactions now always see a
  5489 quasi-functional intermediate checkpoint, both in interactive and
  5490 batch mode.
  5491 
  5492 * Isar: simplified interfaces for outer syntax.  Renamed
  5493 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  5494 OuterSyntax.add_parsers -- this functionality is now included in
  5495 OuterSyntax.command etc.  INCOMPATIBILITY.
  5496 
  5497 * Simplifier: the simpset of a running simplification process now
  5498 contains a proof context (cf. Simplifier.the_context), which is the
  5499 very context that the initial simpset has been retrieved from (by
  5500 simpset_of/local_simpset_of).  Consequently, all plug-in components
  5501 (solver, looper etc.) may depend on arbitrary proof data.
  5502 
  5503 * Simplifier.inherit_context inherits the proof context (plus the
  5504 local bounds) of the current simplification process; any simproc
  5505 etc. that calls the Simplifier recursively should do this!  Removed
  5506 former Simplifier.inherit_bounds, which is already included here --
  5507 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  5508 specify an explicit context using Simplifier.context/theory_context.
  5509 
  5510 * Simplifier/Classical Reasoner: more abstract interfaces
  5511 change_simpset/claset for modifying the simpset/claset reference of a
  5512 theory; raw versions simpset/claset_ref etc. have been discontinued --
  5513 INCOMPATIBILITY.
  5514 
  5515 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  5516 "Trueprop" etc.
  5517 
  5518 
  5519 *** System ***
  5520 
  5521 * settings: the default heap location within ISABELLE_HOME_USER now
  5522 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  5523 Isabelle installations.
  5524 
  5525 * isabelle-process: option -S (secure mode) disables some critical
  5526 operations, notably runtime compilation and evaluation of ML source
  5527 code.
  5528 
  5529 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  5530 
  5531 * Support for parallel execution, using native multicore support of
  5532 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  5533 independent theories, according to the given theory header
  5534 specifications. The maximum number of worker threads is specified via
  5535 usedir option -M or the "max-threads" setting in Proof General. A
  5536 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  5537 to 6 on a 8-core machine.  User-code needs to observe certain
  5538 guidelines for thread-safe programming, see appendix A in the Isar
  5539 Implementation manual.
  5540 
  5541 
  5542 
  5543 New in Isabelle2005 (October 2005)
  5544 ----------------------------------
  5545 
  5546 *** General ***
  5547 
  5548 * Theory headers: the new header syntax for Isar theories is
  5549 
  5550   theory <name>
  5551   imports <theory1> ... <theoryN>
  5552   uses <file1> ... <fileM>
  5553   begin
  5554 
  5555 where the 'uses' part is optional.  The previous syntax
  5556 
  5557   theory <name> = <theory1> + ... + <theoryN>:
  5558 
  5559 will disappear in the next release.  Use isatool fixheaders to convert
  5560 existing theory files.  Note that there is no change in ancient
  5561 non-Isar theories now, but these will disappear soon.
  5562 
  5563 * Theory loader: parent theories can now also be referred to via
  5564 relative and absolute paths.
  5565 
  5566 * Command 'find_theorems' searches for a list of criteria instead of a
  5567 list of constants. Known criteria are: intro, elim, dest, name:string,
  5568 simp:term, and any term. Criteria can be preceded by '-' to select
  5569 theorems that do not match. Intro, elim, dest select theorems that
  5570 match the current goal, name:s selects theorems whose fully qualified
  5571 name contain s, and simp:term selects all simplification rules whose
  5572 lhs match term.  Any other term is interpreted as pattern and selects
  5573 all theorems matching the pattern. Available in ProofGeneral under
  5574 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  5575 
  5576   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  5577 
  5578 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  5579 matching the current goal as introduction rule and not having "HOL."
  5580 in their name (i.e. not being defined in theory HOL).
  5581 
  5582 * Command 'thms_containing' has been discontinued in favour of
  5583 'find_theorems'; INCOMPATIBILITY.
  5584 
  5585 * Communication with Proof General is now 8bit clean, which means that
  5586 Unicode text in UTF-8 encoding may be used within theory texts (both
  5587 formal and informal parts).  Cf. option -U of the Isabelle Proof
  5588 General interface.  Here are some simple examples (cf. src/HOL/ex):
  5589 
  5590   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  5591   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  5592 
  5593 * Improved efficiency of the Simplifier and, to a lesser degree, the
  5594 Classical Reasoner.  Typical big applications run around 2 times
  5595 faster.
  5596 
  5597 
  5598 *** Document preparation ***
  5599 
  5600 * Commands 'display_drafts' and 'print_drafts' perform simple output
  5601 of raw sources.  Only those symbols that do not require additional
  5602 LaTeX packages (depending on comments in isabellesym.sty) are
  5603 displayed properly, everything else is left verbatim.  isatool display
  5604 and isatool print are used as front ends (these are subject to the
  5605 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  5606 
  5607 * Command tags control specific markup of certain regions of text,
  5608 notably folding and hiding.  Predefined tags include "theory" (for
  5609 theory begin and end), "proof" for proof commands, and "ML" for
  5610 commands involving ML code; the additional tags "visible" and
  5611 "invisible" are unused by default.  Users may give explicit tag
  5612 specifications in the text, e.g. ''by %invisible (auto)''.  The
  5613 interpretation of tags is determined by the LaTeX job during document
  5614 preparation: see option -V of isatool usedir, or options -n and -t of
  5615 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  5616 \isadroptag.
  5617 
  5618 Several document versions may be produced at the same time via isatool
  5619 usedir (the generated index.html will link all of them).  Typical
  5620 specifications include ''-V document=theory,proof,ML'' to present
  5621 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  5622 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  5623 these parts without any formal replacement text.  The Isabelle site
  5624 default settings produce ''document'' and ''outline'' versions as
  5625 specified above.
  5626 
  5627 * Several new antiquotations:
  5628 
  5629   @{term_type term} prints a term with its type annotated;
  5630 
  5631   @{typeof term} prints the type of a term;
  5632 
  5633   @{const const} is the same as @{term const}, but checks that the
  5634   argument is a known logical constant;
  5635 
  5636   @{term_style style term} and @{thm_style style thm} print a term or
  5637   theorem applying a "style" to it
  5638 
  5639   @{ML text}
  5640 
  5641 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  5642 definitions, equations, inequations etc., 'concl' printing only the
  5643 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  5644 to print the specified premise.  TermStyle.add_style provides an ML
  5645 interface for introducing further styles.  See also the "LaTeX Sugar"
  5646 document practical applications.  The ML antiquotation prints
  5647 type-checked ML expressions verbatim.
  5648 
  5649 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  5650 and 'text' support optional locale specification '(in loc)', which
  5651 specifies the default context for interpreting antiquotations.  For
  5652 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  5653 
  5654 * Option 'locale=NAME' of antiquotations specifies an alternative
  5655 context interpreting the subsequent argument.  For example: @{thm
  5656 [locale=lattice] inf_assoc}.
  5657 
  5658 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  5659 a proof context.
  5660 
  5661 * Proper output of antiquotations for theory commands involving a
  5662 proof context (such as 'locale' or 'theorem (in loc) ...').
  5663 
  5664 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  5665 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  5666 
  5667 * isatool usedir: new option -C (default true) controls whether option
  5668 -D should include a copy of the original document directory; -C false
  5669 prevents unwanted effects such as copying of administrative CVS data.
  5670 
  5671 
  5672 *** Pure ***
  5673 
  5674 * Considerably improved version of 'constdefs' command.  Now performs
  5675 automatic type-inference of declared constants; additional support for
  5676 local structure declarations (cf. locales and HOL records), see also
  5677 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  5678 sequential dependencies of definitions within a single 'constdefs'
  5679 section; moreover, the declared name needs to be an identifier.  If
  5680 all fails, consider to fall back on 'consts' and 'defs' separately.
  5681 
  5682 * Improved indexed syntax and implicit structures.  First of all,
  5683 indexed syntax provides a notational device for subscripted
  5684 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  5685 expressions.  Secondly, in a local context with structure
  5686 declarations, number indexes \<^sub>n or the empty index (default
  5687 number 1) refer to a certain fixed variable implicitly; option
  5688 show_structs controls printing of implicit structures.  Typical
  5689 applications of these concepts involve record types and locales.
  5690 
  5691 * New command 'no_syntax' removes grammar declarations (and
  5692 translations) resulting from the given syntax specification, which is
  5693 interpreted in the same manner as for the 'syntax' command.
  5694 
  5695 * 'Advanced' translation functions (parse_translation etc.) may depend
  5696 on the signature of the theory context being presently used for
  5697 parsing/printing, see also isar-ref manual.
  5698 
  5699 * Improved 'oracle' command provides a type-safe interface to turn an
  5700 ML expression of type theory -> T -> term into a primitive rule of
  5701 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  5702 is already included here); see also FOL/ex/IffExample.thy;
  5703 INCOMPATIBILITY.
  5704 
  5705 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  5706 before); "cI" is no longer bound, use "c.intro" instead.
  5707 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  5708 axclasses vs. locales.
  5709 
  5710 * Improved internal renaming of symbolic identifiers -- attach primes
  5711 instead of base 26 numbers.
  5712 
  5713 * New flag show_question_marks controls printing of leading question
  5714 marks in schematic variable names.
  5715 
  5716 * In schematic variable names, *any* symbol following \<^isub> or
  5717 \<^isup> is now treated as part of the base name.  For example, the
  5718 following works without printing of awkward ".0" indexes:
  5719 
  5720   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  5721     by simp
  5722 
  5723 * Inner syntax includes (*(*nested*) comments*).
  5724 
  5725 * Pretty printer now supports unbreakable blocks, specified in mixfix
  5726 annotations as "(00...)".
  5727 
  5728 * Clear separation of logical types and nonterminals, where the latter
  5729 may only occur in 'syntax' specifications or type abbreviations.
  5730 Before that distinction was only partially implemented via type class
  5731 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  5732 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  5733 exotic syntax specifications may require further adaption
  5734 (e.g. Cube/Cube.thy).
  5735 
  5736 * Removed obsolete type class "logic", use the top sort {} instead.
  5737 Note that non-logical types should be declared as 'nonterminals'
  5738 rather than 'types'.  INCOMPATIBILITY for new object-logic
  5739 specifications.
  5740 
  5741 * Attributes 'induct' and 'cases': type or set names may now be
  5742 locally fixed variables as well.
  5743 
  5744 * Simplifier: can now control the depth to which conditional rewriting
  5745 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  5746 Limit.
  5747 
  5748 * Simplifier: simplification procedures may now take the current
  5749 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  5750 interface), which is very useful for calling the Simplifier
  5751 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  5752 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  5753 low-level mk_simproc no longer applies Logic.varify internally, to
  5754 allow for use in a context of fixed variables.
  5755 
  5756 * thin_tac now works even if the assumption being deleted contains !!
  5757 or ==>.  More generally, erule now works even if the major premise of
  5758 the elimination rule contains !! or ==>.
  5759 
  5760 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  5761 
  5762 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  5763 from Pure, which contains all common declarations already.  Both
  5764 theories are defined via plain Isabelle/Isar .thy files.
  5765 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  5766 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  5767 use isatool fixcpure to adapt your theory and ML sources.
  5768 
  5769 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  5770 selections of theorems in named facts via index ranges.
  5771 
  5772 * 'print_theorems': in theory mode, really print the difference
  5773 wrt. the last state (works for interactive theory development only),
  5774 in proof mode print all local facts (cf. 'print_facts');
  5775 
  5776 * 'hide': option '(open)' hides only base names.
  5777 
  5778 * More efficient treatment of intermediate checkpoints in interactive
  5779 theory development.
  5780 
  5781 * Code generator is now invoked via code_module (incremental code
  5782 generation) and code_library (modular code generation, ML structures
  5783 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  5784 must be quoted when used as identifiers.
  5785 
  5786 * New 'value' command for reading, evaluating and printing terms using
  5787 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  5788 quoted when used as identifier.
  5789 
  5790 
  5791 *** Locales ***
  5792 
  5793 * New commands for the interpretation of locale expressions in
  5794 theories (1), locales (2) and proof contexts (3).  These generate
  5795 proof obligations from the expression specification.  After the
  5796 obligations have been discharged, theorems of the expression are added
  5797 to the theory, target locale or proof context.  The synopsis of the
  5798 commands is a follows:
  5799 
  5800   (1) interpretation expr inst
  5801   (2) interpretation target < expr
  5802   (3) interpret expr inst
  5803 
  5804 Interpretation in theories and proof contexts require a parameter
  5805 instantiation of terms from the current context.  This is applied to
  5806 specifications and theorems of the interpreted expression.
  5807 Interpretation in locales only permits parameter renaming through the
  5808 locale expression.  Interpretation is smart in that interpretations
  5809 that are active already do not occur in proof obligations, neither are
  5810 instantiated theorems stored in duplicate.  Use 'print_interps' to
  5811 inspect active interpretations of a particular locale.  For details,
  5812 see the Isar Reference manual.  Examples can be found in
  5813 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  5814 
  5815 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  5816 'interpret' instead.
  5817 
  5818 * New context element 'constrains' for adding type constraints to
  5819 parameters.
  5820 
  5821 * Context expressions: renaming of parameters with syntax
  5822 redeclaration.
  5823 
  5824 * Locale declaration: 'includes' disallowed.
  5825 
  5826 * Proper static binding of attribute syntax -- i.e. types / terms /
  5827 facts mentioned as arguments are always those of the locale definition
  5828 context, independently of the context of later invocations.  Moreover,
  5829 locale operations (renaming and type / term instantiation) are applied
  5830 to attribute arguments as expected.
  5831 
  5832 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5833 actual attributes; rare situations may require Attrib.attribute to
  5834 embed those attributes into Attrib.src that lack concrete syntax.
  5835 Attribute implementations need to cooperate properly with the static
  5836 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5837 Attrib.XXX_thm etc. already do the right thing without further
  5838 intervention.  Only unusual applications -- such as "where" or "of"
  5839 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5840 on the context and the facts involved -- may have to assign parsed
  5841 values to argument tokens explicitly.
  5842 
  5843 * Changed parameter management in theorem generation for long goal
  5844 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5845 theorem statement in rare situations.
  5846 
  5847 * Locale inspection command 'print_locale' omits notes elements.  Use
  5848 'print_locale!' to have them included in the output.
  5849 
  5850 
  5851 *** Provers ***
  5852 
  5853 * Provers/hypsubst.ML: improved version of the subst method, for
  5854 single-step rewriting: it now works in bound variable contexts. New is
  5855 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5856 rewrite a different subterm than the original subst method, which is
  5857 still available as 'simplesubst'.
  5858 
  5859 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5860 and quasi orders.
  5861 
  5862 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5863 reflexive-transitive closure of relations.
  5864 
  5865 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5866 limit (previously hard-coded with a value of 20) user-definable.
  5867 
  5868 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5869 is peformed already.  Object-logics merely need to finish their
  5870 initial simpset configuration as before.  INCOMPATIBILITY.
  5871 
  5872 
  5873 *** HOL ***
  5874 
  5875 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5876 
  5877   syntax (epsilon)
  5878     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5879 
  5880 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5881 and x-symbol; use option '-m epsilon' to get it actually printed.
  5882 Moreover, the mathematically important symbolic identifier \<epsilon>
  5883 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5884 
  5885 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5886 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5887 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5888 support corresponding Isar calculations.
  5889 
  5890 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5891 instead of ":".
  5892 
  5893 * theory SetInterval: changed the syntax for open intervals:
  5894 
  5895   Old       New
  5896   {..n(}    {..<n}
  5897   {)n..}    {n<..}
  5898   {m..n(}   {m..<n}
  5899   {)m..n}   {m<..n}
  5900   {)m..n(}  {m<..<n}
  5901 
  5902 The old syntax is still supported but will disappear in the next
  5903 release.  For conversion use the following Emacs search and replace
  5904 patterns (these are not perfect but work quite well):
  5905 
  5906   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5907   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5908 
  5909 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5910 equalities in commutative rings; method 'algebra' provides a generic
  5911 interface.
  5912 
  5913 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5914 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5915 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5916 be a tuple pattern.
  5917 
  5918 Some new syntax forms are available:
  5919 
  5920   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5921   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5922   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5923   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5924 
  5925 The latter form "\<Sum>x < k. e" used to be based on a separate
  5926 function "Summation", which has been discontinued.
  5927 
  5928 * theory Finite_Set: in structured induction proofs, the insert case
  5929 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5930 (insert F x)'.
  5931 
  5932 * The 'refute' command has been extended to support a much larger
  5933 fragment of HOL, including axiomatic type classes, constdefs and
  5934 typedefs, inductive datatypes and recursion.
  5935 
  5936 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5937 Requires zChaff with proof generation to be installed.  See
  5938 HOL/ex/SAT_Examples.thy for examples.
  5939 
  5940 * Datatype induction via method 'induct' now preserves the name of the
  5941 induction variable. For example, when proving P(xs::'a list) by
  5942 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5943 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5944 in unstructured proof scripts.
  5945 
  5946 * Reworked implementation of records.  Improved scalability for
  5947 records with many fields, avoiding performance problems for type
  5948 inference. Records are no longer composed of nested field types, but
  5949 of nested extension types. Therefore the record type only grows linear
  5950 in the number of extensions and not in the number of fields.  The
  5951 top-level (users) view on records is preserved.  Potential
  5952 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5953 old record representation. The type generated for a record is called
  5954 <record_name>_ext_type.
  5955 
  5956 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5957 proofs triggered by a record definition or a simproc (if
  5958 quick_and_dirty is enabled).  Definitions of large records can take
  5959 quite long.
  5960 
  5961 New simproc record_upd_simproc for simplification of multiple record
  5962 updates enabled by default.  Moreover, trivial updates are also
  5963 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5964 occasionally, since simplification is more powerful by default.
  5965 
  5966 * typedef: proper support for polymorphic sets, which contain extra
  5967 type-variables in the term.
  5968 
  5969 * Simplifier: automatically reasons about transitivity chains
  5970 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5971 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5972 old proofs break occasionally as simplification may now solve more
  5973 goals than previously.
  5974 
  5975 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5976 present.  Works for all partial orders (class "order"), in particular
  5977 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5978 just like y <= x.
  5979 
  5980 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5981 bound variable or a constant then the let is unfolded.  Otherwise
  5982 first a is simplified to b, and then f b is simplified to g. If
  5983 possible we abstract b from g arriving at "let x = b in h x",
  5984 otherwise we unfold the let and arrive at g.  The simproc can be
  5985 enabled/disabled by the reference use_let_simproc.  Potential
  5986 INCOMPATIBILITY since simplification is more powerful by default.
  5987 
  5988 * Classical reasoning: the meson method now accepts theorems as arguments.
  5989 
  5990 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5991 jobs to provide advice on the provability of subgoals.
  5992 
  5993 * Theory OrderedGroup and Ring_and_Field: various additions and
  5994 improvements to faciliate calculations involving equalities and
  5995 inequalities.
  5996 
  5997 The following theorems have been eliminated or modified
  5998 (INCOMPATIBILITY):
  5999 
  6000   abs_eq             now named abs_of_nonneg
  6001   abs_of_ge_0        now named abs_of_nonneg
  6002   abs_minus_eq       now named abs_of_nonpos
  6003   imp_abs_id         now named abs_of_nonneg
  6004   imp_abs_neg_id     now named abs_of_nonpos
  6005   mult_pos           now named mult_pos_pos
  6006   mult_pos_le        now named mult_nonneg_nonneg
  6007   mult_pos_neg_le    now named mult_nonneg_nonpos
  6008   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  6009   mult_neg           now named mult_neg_neg
  6010   mult_neg_le        now named mult_nonpos_nonpos
  6011 
  6012 * The following lemmas in Ring_and_Field have been added to the simplifier:
  6013      
  6014      zero_le_square
  6015      not_square_less_zero 
  6016 
  6017   The following lemmas have been deleted from Real/RealPow:
  6018   
  6019      realpow_zero_zero
  6020      realpow_two
  6021      realpow_less
  6022      zero_le_power
  6023      realpow_two_le
  6024      abs_realpow_two
  6025      realpow_two_abs     
  6026 
  6027 * Theory Parity: added rules for simplifying exponents.
  6028 
  6029 * Theory List:
  6030 
  6031 The following theorems have been eliminated or modified
  6032 (INCOMPATIBILITY):
  6033 
  6034   list_all_Nil       now named list_all.simps(1)
  6035   list_all_Cons      now named list_all.simps(2)
  6036   list_all_conv      now named list_all_iff
  6037   set_mem_eq         now named mem_iff
  6038 
  6039 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  6040 asymptotic "big O" calculations.  See the notes in BigO.thy.
  6041 
  6042 
  6043 *** HOL-Complex ***
  6044 
  6045 * Theory RealDef: better support for embedding natural numbers and
  6046 integers in the reals.
  6047 
  6048 The following theorems have been eliminated or modified
  6049 (INCOMPATIBILITY):
  6050 
  6051   exp_ge_add_one_self  now requires no hypotheses
  6052   real_of_int_add      reversed direction of equality (use [symmetric])
  6053   real_of_int_minus    reversed direction of equality (use [symmetric])
  6054   real_of_int_diff     reversed direction of equality (use [symmetric])
  6055   real_of_int_mult     reversed direction of equality (use [symmetric])
  6056 
  6057 * Theory RComplete: expanded support for floor and ceiling functions.
  6058 
  6059 * Theory Ln is new, with properties of the natural logarithm
  6060 
  6061 * Hyperreal: There is a new type constructor "star" for making
  6062 nonstandard types.  The old type names are now type synonyms:
  6063 
  6064   hypreal = real star
  6065   hypnat = nat star
  6066   hcomplex = complex star
  6067 
  6068 * Hyperreal: Many groups of similarly-defined constants have been
  6069 replaced by polymorphic versions (INCOMPATIBILITY):
  6070 
  6071   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  6072 
  6073   starset      <-- starsetNat, starsetC
  6074   *s*          <-- *sNat*, *sc*
  6075   starset_n    <-- starsetNat_n, starsetC_n
  6076   *sn*         <-- *sNatn*, *scn*
  6077   InternalSets <-- InternalNatSets, InternalCSets
  6078 
  6079   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  6080   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  6081   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  6082   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  6083   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  6084 
  6085 * Hyperreal: Many type-specific theorems have been removed in favor of
  6086 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  6087 
  6088   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  6089   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  6090   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  6091   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  6092   right_minus <-- hypreal_add_minus
  6093   left_minus <-- {hypreal,hcomplex}_add_minus_left
  6094   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  6095   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  6096   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  6097   mult_1_right <-- hcomplex_mult_one_right
  6098   mult_zero_left <-- hcomplex_mult_zero_left
  6099   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  6100   right_distrib <-- hypnat_add_mult_distrib2
  6101   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  6102   right_inverse <-- hypreal_mult_inverse
  6103   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  6104   order_refl <-- {hypreal,hypnat}_le_refl
  6105   order_trans <-- {hypreal,hypnat}_le_trans
  6106   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  6107   order_less_le <-- {hypreal,hypnat}_less_le
  6108   linorder_linear <-- {hypreal,hypnat}_le_linear
  6109   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  6110   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  6111   add_nonneg_nonneg <-- hypreal_le_add_order
  6112 
  6113 * Hyperreal: Separate theorems having to do with type-specific
  6114 versions of constants have been merged into theorems that apply to the
  6115 new polymorphic constants (INCOMPATIBILITY):
  6116 
  6117   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  6118   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  6119   STAR_Un <-- {STAR,NatStar,STARC}_Un
  6120   STAR_Int <-- {STAR,NatStar,STARC}_Int
  6121   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  6122   STAR_subset <-- {STAR,NatStar,STARC}_subset
  6123   STAR_mem <-- {STAR,NatStar,STARC}_mem
  6124   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  6125   STAR_diff <-- {STAR,STARC}_diff
  6126   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  6127     STARC_hcomplex_of_complex}_image_subset
  6128   starset_n_Un <-- starset{Nat,C}_n_Un
  6129   starset_n_Int <-- starset{Nat,C}_n_Int
  6130   starset_n_Compl <-- starset{Nat,C}_n_Compl
  6131   starset_n_diff <-- starset{Nat,C}_n_diff
  6132   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  6133   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  6134   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  6135   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  6136   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  6137   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  6138   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  6139   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  6140   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  6141   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  6142   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  6143   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  6144   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  6145   starfun_diff <-- starfun{C,RC,CR}_diff
  6146   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  6147   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  6148   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  6149   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  6150   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  6151   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  6152   starfun_Id <-- starfunC_Id
  6153   starfun_approx <-- starfun{Nat,CR}_approx
  6154   starfun_capprox <-- starfun{C,RC}_capprox
  6155   starfun_abs <-- starfunNat_rabs
  6156   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  6157   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  6158   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  6159   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  6160   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  6161   starfun_add_approx <-- starfunCR_add_approx
  6162   starfun_inverse_inverse <-- starfunC_inverse_inverse
  6163   starfun_divide <-- starfun{C,CR,RC}_divide
  6164   starfun_n <-- starfun{Nat,C}_n
  6165   starfun_n_mult <-- starfun{Nat,C}_n_mult
  6166   starfun_n_add <-- starfun{Nat,C}_n_add
  6167   starfun_n_add_minus <-- starfunNat_n_add_minus
  6168   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  6169   starfun_n_minus <-- starfun{Nat,C}_n_minus
  6170   starfun_n_eq <-- starfun{Nat,C}_n_eq
  6171 
  6172   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  6173   star_n_minus <-- {hypreal,hcomplex}_minus
  6174   star_n_diff <-- {hypreal,hcomplex}_diff
  6175   star_n_mult <-- {hypreal,hcomplex}_mult
  6176   star_n_inverse <-- {hypreal,hcomplex}_inverse
  6177   star_n_le <-- {hypreal,hypnat}_le
  6178   star_n_less <-- {hypreal,hypnat}_less
  6179   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  6180   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  6181   star_n_abs <-- hypreal_hrabs
  6182   star_n_divide <-- hcomplex_divide
  6183 
  6184   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  6185   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  6186   star_of_diff <-- hypreal_of_real_diff
  6187   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  6188   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  6189   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  6190   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  6191   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  6192   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  6193   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  6194   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  6195   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  6196   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  6197   star_of_number_of <-- {hypreal,hcomplex}_number_of
  6198   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  6199   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  6200   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  6201   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  6202   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  6203   star_of_power <-- hypreal_of_real_power
  6204   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  6205 
  6206 * Hyperreal: new method "transfer" that implements the transfer
  6207 principle of nonstandard analysis. With a subgoal that mentions
  6208 nonstandard types like "'a star", the command "apply transfer"
  6209 replaces it with an equivalent one that mentions only standard types.
  6210 To be successful, all free variables must have standard types; non-
  6211 standard variables must have explicit universal quantifiers.
  6212 
  6213 * Hyperreal: A theory of Taylor series.
  6214 
  6215 
  6216 *** HOLCF ***
  6217 
  6218 * Discontinued special version of 'constdefs' (which used to support
  6219 continuous functions) in favor of the general Pure one with full
  6220 type-inference.
  6221 
  6222 * New simplification procedure for solving continuity conditions; it
  6223 is much faster on terms with many nested lambda abstractions (cubic
  6224 instead of exponential time).
  6225 
  6226 * New syntax for domain package: selector names are now optional.
  6227 Parentheses should be omitted unless argument is lazy, for example:
  6228 
  6229   domain 'a stream = cons "'a" (lazy "'a stream")
  6230 
  6231 * New command 'fixrec' for defining recursive functions with pattern
  6232 matching; defining multiple functions with mutual recursion is also
  6233 supported.  Patterns may include the constants cpair, spair, up, sinl,
  6234 sinr, or any data constructor defined by the domain package. The given
  6235 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  6236 syntax and examples.
  6237 
  6238 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  6239 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  6240 but the proof obligation additionally includes an admissibility
  6241 requirement. The packages generate instances of class cpo or pcpo,
  6242 with continuity and strictness theorems for Rep and Abs.
  6243 
  6244 * HOLCF: Many theorems have been renamed according to a more standard naming
  6245 scheme (INCOMPATIBILITY):
  6246 
  6247   foo_inject:  "foo$x = foo$y ==> x = y"
  6248   foo_eq:      "(foo$x = foo$y) = (x = y)"
  6249   foo_less:    "(foo$x << foo$y) = (x << y)"
  6250   foo_strict:  "foo$UU = UU"
  6251   foo_defined: "... ==> foo$x ~= UU"
  6252   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  6253 
  6254 
  6255 *** ZF ***
  6256 
  6257 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  6258 including the First Isomorphism Theorem (on quotienting by the kernel
  6259 of a homomorphism).
  6260 
  6261 * ZF/Simplifier: install second copy of type solver that actually
  6262 makes use of TC rules declared to Isar proof contexts (or locales);
  6263 the old version is still required for ML proof scripts.
  6264 
  6265 
  6266 *** Cube ***
  6267 
  6268 * Converted to Isar theory format; use locales instead of axiomatic
  6269 theories.
  6270 
  6271 
  6272 *** ML ***
  6273 
  6274 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  6275 for ||>, ||>>, |>>,
  6276 
  6277 * Pure/library.ML no longer defines its own option datatype, but uses
  6278 that of the SML basis, which has constructors NONE and SOME instead of
  6279 None and Some, as well as exception Option.Option instead of OPTION.
  6280 The functions the, if_none, is_some, is_none have been adapted
  6281 accordingly, while Option.map replaces apsome.
  6282 
  6283 * Pure/library.ML: the exception LIST has been given up in favour of
  6284 the standard exceptions Empty and Subscript, as well as
  6285 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6286 superceded by the standard hd and tl functions etc.
  6287 
  6288 A number of basic list functions are no longer exported to the ML
  6289 toplevel, as they are variants of predefined functions.  The following
  6290 suggests how one can translate existing code:
  6291 
  6292     rev_append xs ys = List.revAppend (xs, ys)
  6293     nth_elem (i, xs) = List.nth (xs, i)
  6294     last_elem xs = List.last xs
  6295     flat xss = List.concat xss
  6296     seq fs = List.app fs
  6297     partition P xs = List.partition P xs
  6298     mapfilter f xs = List.mapPartial f xs
  6299 
  6300 * Pure/library.ML: several combinators for linear functional
  6301 transformations, notably reverse application and composition:
  6302 
  6303   x |> f                f #> g
  6304   (x, y) |-> f          f #-> g
  6305 
  6306 * Pure/library.ML: introduced/changed precedence of infix operators:
  6307 
  6308   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6309   infix 2 ?;
  6310   infix 3 o oo ooo oooo;
  6311   infix 4 ~~ upto downto;
  6312 
  6313 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6314 infix operators.
  6315 
  6316 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6317 fold_map support linear functional transformations and nesting.  For
  6318 example:
  6319 
  6320   fold f [x1, ..., xN] y =
  6321     y |> f x1 |> ... |> f xN
  6322 
  6323   (fold o fold) f [xs1, ..., xsN] y =
  6324     y |> fold f xs1 |> ... |> fold f xsN
  6325 
  6326   fold f [x1, ..., xN] =
  6327     f x1 #> ... #> f xN
  6328 
  6329   (fold o fold) f [xs1, ..., xsN] =
  6330     fold f xs1 #> ... #> fold f xsN
  6331 
  6332 * Pure/library.ML: the following selectors on type 'a option are
  6333 available:
  6334 
  6335   the:               'a option -> 'a  (*partial*)
  6336   these:             'a option -> 'a  where 'a = 'b list
  6337   the_default: 'a -> 'a option -> 'a
  6338   the_list:          'a option -> 'a list
  6339 
  6340 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6341 basic operations for association lists, following natural argument
  6342 order; moreover the explicit equality predicate passed here avoids
  6343 potentially expensive polymorphic runtime equality checks.
  6344 The old functions may be expressed as follows:
  6345 
  6346   assoc = uncurry (AList.lookup (op =))
  6347   assocs = these oo AList.lookup (op =)
  6348   overwrite = uncurry (AList.update (op =)) o swap
  6349 
  6350 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6351 
  6352   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6353   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6354 
  6355 replacing make_keylist and keyfilter (occassionally used)
  6356 Naive rewrites:
  6357 
  6358   make_keylist = AList.make
  6359   keyfilter = AList.find (op =)
  6360 
  6361 * eq_fst and eq_snd now take explicit equality parameter, thus
  6362   avoiding eqtypes. Naive rewrites:
  6363 
  6364     eq_fst = eq_fst (op =)
  6365     eq_snd = eq_snd (op =)
  6366 
  6367 * Removed deprecated apl and apr (rarely used).
  6368   Naive rewrites:
  6369 
  6370     apl (n, op) =>>= curry op n
  6371     apr (op, m) =>>= fn n => op (n, m)
  6372 
  6373 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6374 provides a reasonably efficient light-weight implementation of sets as
  6375 lists.
  6376 
  6377 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6378 few new operations; existing lookup and update are now curried to
  6379 follow natural argument order (for use with fold etc.);
  6380 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6381 
  6382 * Pure/General: output via the Isabelle channels of
  6383 writeln/warning/error etc. is now passed through Output.output, with a
  6384 hook for arbitrary transformations depending on the print_mode
  6385 (cf. Output.add_mode -- the first active mode that provides a output
  6386 function wins).  Already formatted output may be embedded into further
  6387 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6388 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6389 accommodate easy composition of diagnostic messages etc.  Programmers
  6390 rarely need to care about Output.output or Output.raw at all, with
  6391 some notable exceptions: Output.output is required when bypassing the
  6392 standard channels (writeln etc.), or in token translations to produce
  6393 properly formatted results; Output.raw is required when capturing
  6394 already output material that will eventually be presented to the user
  6395 a second time.  For the default print mode, both Output.output and
  6396 Output.raw have no effect.
  6397 
  6398 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6399 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6400 cumulative results are displayed at the end of a batch session.
  6401 
  6402 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6403 replaced by File.platform_path and File.shell_path (with appropriate
  6404 hooks).  This provides a clean interface for unusual systems where the
  6405 internal and external process view of file names are different.
  6406 
  6407 * Pure: more efficient orders for basic syntactic entities: added
  6408 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6409 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6410 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6411 orders now -- potential INCOMPATIBILITY for code that depends on a
  6412 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6413 Library.sort_strings on result).
  6414 
  6415 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6416 fold_types traverse types/terms from left to right, observing natural
  6417 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6418 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6419 
  6420 * Pure: name spaces have been refined, with significant changes of the
  6421 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6422 to extern(_table).  The plain name entry path is superceded by a
  6423 general 'naming' context, which also includes the 'policy' to produce
  6424 a fully qualified name and external accesses of a fully qualified
  6425 name; NameSpace.extend is superceded by context dependent
  6426 Sign.declare_name.  Several theory and proof context operations modify
  6427 the naming context.  Especially note Theory.restore_naming and
  6428 ProofContext.restore_naming to get back to a sane state; note that
  6429 Theory.add_path is no longer sufficient to recover from
  6430 Theory.absolute_path in particular.
  6431 
  6432 * Pure: new flags short_names (default false) and unique_names
  6433 (default true) for controlling output of qualified names.  If
  6434 short_names is set, names are printed unqualified.  If unique_names is
  6435 reset, the name prefix is reduced to the minimum required to achieve
  6436 the original result when interning again, even if there is an overlap
  6437 with earlier declarations.
  6438 
  6439 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  6440 now 'extend', and 'merge' gets an additional Pretty.pp argument
  6441 (useful for printing error messages).  INCOMPATIBILITY.
  6442 
  6443 * Pure: major reorganization of the theory context.  Type Sign.sg and
  6444 Theory.theory are now identified, referring to the universal
  6445 Context.theory (see Pure/context.ML).  Actual signature and theory
  6446 content is managed as theory data.  The old code and interfaces were
  6447 spread over many files and structures; the new arrangement introduces
  6448 considerable INCOMPATIBILITY to gain more clarity:
  6449 
  6450   Context -- theory management operations (name, identity, inclusion,
  6451     parents, ancestors, merge, etc.), plus generic theory data;
  6452 
  6453   Sign -- logical signature and syntax operations (declaring consts,
  6454     types, etc.), plus certify/read for common entities;
  6455 
  6456   Theory -- logical theory operations (stating axioms, definitions,
  6457     oracles), plus a copy of logical signature operations (consts,
  6458     types, etc.); also a few basic management operations (Theory.copy,
  6459     Theory.merge, etc.)
  6460 
  6461 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  6462 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  6463 for convenience -- they merely return the theory.
  6464 
  6465 * Pure: type Type.tsig is superceded by theory in most interfaces.
  6466 
  6467 * Pure: the Isar proof context type is already defined early in Pure
  6468 as Context.proof (note that ProofContext.context and Proof.context are
  6469 aliases, where the latter is the preferred name).  This enables other
  6470 Isabelle components to refer to that type even before Isar is present.
  6471 
  6472 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  6473 typeK, constK, axiomK, oracleK), but provide explicit operations for
  6474 any of these kinds.  For example, Sign.intern typeK is now
  6475 Sign.intern_type, Theory.hide_space Sign.typeK is now
  6476 Theory.hide_types.  Also note that former
  6477 Theory.hide_classes/types/consts are now
  6478 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  6479 internalize their arguments!  INCOMPATIBILITY.
  6480 
  6481 * Pure: get_thm interface (of PureThy and ProofContext) expects
  6482 datatype thmref (with constructors Name and NameSelection) instead of
  6483 plain string -- INCOMPATIBILITY;
  6484 
  6485 * Pure: cases produced by proof methods specify options, where NONE
  6486 means to remove case bindings -- INCOMPATIBILITY in
  6487 (RAW_)METHOD_CASES.
  6488 
  6489 * Pure: the following operations retrieve axioms or theorems from a
  6490 theory node or theory hierarchy, respectively:
  6491 
  6492   Theory.axioms_of: theory -> (string * term) list
  6493   Theory.all_axioms_of: theory -> (string * term) list
  6494   PureThy.thms_of: theory -> (string * thm) list
  6495   PureThy.all_thms_of: theory -> (string * thm) list
  6496 
  6497 * Pure: print_tac now outputs the goal through the trace channel.
  6498 
  6499 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  6500 Reference Toplevel.debug (default false) controls detailed printing
  6501 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  6502 controls execution profiling -- set to 1 for time and 2 for space
  6503 (both increase the runtime).
  6504 
  6505 * Isar session: The initial use of ROOT.ML is now always timed,
  6506 i.e. the log will show the actual process times, in contrast to the
  6507 elapsed wall-clock time that the outer shell wrapper produces.
  6508 
  6509 * Simplifier: improved handling of bound variables (nameless
  6510 representation, avoid allocating new strings).  Simprocs that invoke
  6511 the Simplifier recursively should use Simplifier.inherit_bounds to
  6512 avoid local name clashes.  Failure to do so produces warnings
  6513 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  6514 for further details.
  6515 
  6516 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  6517 bindings for all theorems stored within a given theory; this may help
  6518 in porting non-Isar theories to Isar ones, while keeping ML proof
  6519 scripts for the time being.
  6520 
  6521 * ML operator HTML.with_charset specifies the charset begin used for
  6522 generated HTML files.  For example:
  6523 
  6524   HTML.with_charset "utf-8" use_thy "Hebrew";
  6525   HTML.with_charset "utf-8" use_thy "Chinese";
  6526 
  6527 
  6528 *** System ***
  6529 
  6530 * Allow symlinks to all proper Isabelle executables (Isabelle,
  6531 isabelle, isatool etc.).
  6532 
  6533 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  6534 isatool doc, isatool mkdir, display_drafts etc.).
  6535 
  6536 * isatool usedir: option -f allows specification of the ML file to be
  6537 used by Isabelle; default is ROOT.ML.
  6538 
  6539 * New isatool version outputs the version identifier of the Isabelle
  6540 distribution being used.
  6541 
  6542 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  6543 (containing Boolean satisfiability problems) into Isabelle/HOL
  6544 theories.
  6545 
  6546 
  6547 
  6548 New in Isabelle2004 (April 2004)
  6549 --------------------------------
  6550 
  6551 *** General ***
  6552 
  6553 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  6554   Replaces linorder.ML.
  6555 
  6556 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  6557   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  6558   (\<a>...\<z>), are now considered normal letters, and can therefore
  6559   be used anywhere where an ASCII letter (a...zA...Z) has until
  6560   now. COMPATIBILITY: This obviously changes the parsing of some
  6561   terms, especially where a symbol has been used as a binder, say
  6562   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  6563   as an identifier.  Fix it by inserting a space around former
  6564   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  6565   existing theory and ML files.
  6566 
  6567 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  6568 
  6569 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  6570   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  6571   a normal (but invisible) letter. For multiple letter subscripts repeat
  6572   \<^isub> like this: x\<^isub>1\<^isub>2.
  6573 
  6574 * Pure: There are now sub-/superscripts that can span more than one
  6575   character. Text between \<^bsub> and \<^esub> is set in subscript in
  6576   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  6577   superscript. The new control characters are not identifier parts.
  6578 
  6579 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  6580   content of "..." to the latex file instead of \isacntrl... . The "..."
  6581   may consist of any printable characters excluding the end bracket >.
  6582 
  6583 * Pure: Using new Isar command "finalconsts" (or the ML functions
  6584   Theory.add_finals or Theory.add_finals_i) it is now possible to
  6585   declare constants "final", which prevents their being given a definition
  6586   later.  It is useful for constants whose behaviour is fixed axiomatically
  6587   rather than definitionally, such as the meta-logic connectives.
  6588 
  6589 * Pure: 'instance' now handles general arities with general sorts
  6590   (i.e. intersections of classes),
  6591 
  6592 * Presentation: generated HTML now uses a CSS style sheet to make layout
  6593   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  6594   It can be changed to alter the colors/layout of generated pages.
  6595 
  6596 
  6597 *** Isar ***
  6598 
  6599 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  6600   cut_tac, subgoal_tac and thin_tac:
  6601   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  6602     locales are no longer forced to write Isar proof scripts.
  6603     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  6604     emulations.
  6605   - INCOMPATIBILITY: names of variables to be instantiated may no
  6606     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  6607     This is consistent with the instantiation attribute "where".
  6608 
  6609 * Attributes "where" and "of":
  6610   - Now take type variables of instantiated theorem into account when reading
  6611     the instantiation string.  This fixes a bug that caused instantiated
  6612     theorems to have too special types in some circumstances.
  6613   - "where" permits explicit instantiations of type variables.
  6614 
  6615 * Calculation commands "moreover" and "also" no longer interfere with
  6616   current facts ("this"), admitting arbitrary combinations with "then"
  6617   and derived forms.
  6618 
  6619 * Locales:
  6620   - Goal statements involving the context element "includes" no longer
  6621     generate theorems with internal delta predicates (those ending on
  6622     "_axioms") in the premise.
  6623     Resolve particular premise with <locale>.intro to obtain old form.
  6624   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  6625     specification and "includes" elements in goal statement.
  6626   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  6627     [intro?] and [elim?] (respectively) by default.
  6628   - Experimental command for instantiation of locales in proof contexts:
  6629         instantiate <label>[<attrs>]: <loc>
  6630     Instantiates locale <loc> and adds all its theorems to the current context
  6631     taking into account their attributes.  Label and attrs are optional
  6632     modifiers, like in theorem declarations.  If present, names of
  6633     instantiated theorems are qualified with <label>, and the attributes
  6634     <attrs> are applied after any attributes these theorems might have already.
  6635       If the locale has assumptions, a chained fact of the form
  6636     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  6637     are derived.  The command does not support old-style locales declared
  6638     with "locale (open)".
  6639       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  6640 
  6641 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  6642   (Isar) contexts.
  6643 
  6644 
  6645 *** HOL ***
  6646 
  6647 * Proof import: new image HOL4 contains the imported library from
  6648   the HOL4 system with about 2500 theorems. It is imported by
  6649   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  6650   can be used like any other Isabelle image.  See
  6651   HOL/Import/HOL/README for more information.
  6652 
  6653 * Simplifier:
  6654   - Much improved handling of linear and partial orders.
  6655     Reasoners for linear and partial orders are set up for type classes
  6656     "linorder" and "order" respectively, and are added to the default simpset
  6657     as solvers.  This means that the simplifier can build transitivity chains
  6658     to solve goals from the assumptions.
  6659   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  6660     of blast or auto after simplification become unnecessary because the goal
  6661     is solved by simplification already.
  6662 
  6663 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  6664     all proved in axiomatic type classes for semirings, rings and fields.
  6665 
  6666 * Numerics:
  6667   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  6668     now formalized using the Ring_and_Field theory mentioned above.
  6669   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  6670     than before, because now they are set up once in a generic manner.
  6671   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  6672     Look for the general versions in Ring_and_Field (and Power if they concern
  6673     exponentiation).
  6674 
  6675 * Type "rat" of the rational numbers is now available in HOL-Complex.
  6676 
  6677 * Records:
  6678   - Record types are now by default printed with their type abbreviation
  6679     instead of the list of all field types. This can be configured via
  6680     the reference "print_record_type_abbr".
  6681   - Simproc "record_upd_simproc" for simplification of multiple updates added
  6682     (not enabled by default).
  6683   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  6684     EX x. x = sel r to True (not enabled by default).
  6685   - Tactic "record_split_simp_tac" to split and simplify records added.
  6686 
  6687 * 'specification' command added, allowing for definition by
  6688   specification.  There is also an 'ax_specification' command that
  6689   introduces the new constants axiomatically.
  6690 
  6691 * arith(_tac) is now able to generate counterexamples for reals as well.
  6692 
  6693 * HOL-Algebra: new locale "ring" for non-commutative rings.
  6694 
  6695 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  6696   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  6697 
  6698 * HOL-Matrix: a first theory for matrices in HOL with an application of
  6699   matrix theory to linear programming.
  6700 
  6701 * Unions and Intersections:
  6702   The latex output syntax of UN and INT has been changed
  6703   from "\Union x \in A. B" to "\Union_{x \in A} B"
  6704   i.e. the index formulae has become a subscript.
  6705   Similarly for "\Union x. B", and for \Inter instead of \Union.
  6706 
  6707 * Unions and Intersections over Intervals:
  6708   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  6709   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  6710   like in normal math, and corresponding versions for < and for intersection.
  6711 
  6712 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  6713   lexicographic dictonary ordering has been added as "lexord".
  6714 
  6715 * ML: the legacy theory structures Int and List have been removed. They had
  6716   conflicted with ML Basis Library structures having the same names.
  6717 
  6718 * 'refute' command added to search for (finite) countermodels.  Only works
  6719   for a fragment of HOL.  The installation of an external SAT solver is
  6720   highly recommended.  See "HOL/Refute.thy" for details.
  6721 
  6722 * 'quickcheck' command: Allows to find counterexamples by evaluating
  6723   formulae under an assignment of free variables to random values.
  6724   In contrast to 'refute', it can deal with inductive datatypes,
  6725   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  6726   for examples.
  6727 
  6728 
  6729 *** HOLCF ***
  6730 
  6731 * Streams now come with concatenation and are part of the HOLCF image
  6732 
  6733 
  6734 
  6735 New in Isabelle2003 (May 2003)
  6736 ------------------------------
  6737 
  6738 *** General ***
  6739 
  6740 * Provers/simplifier:
  6741 
  6742   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  6743     Assumptions are now subject to complete mutual simplification,
  6744     not just from left to right. The simplifier now preserves
  6745     the order of assumptions.
  6746 
  6747     Potential INCOMPATIBILITY:
  6748 
  6749     -- simp sometimes diverges where the old version did
  6750        not, e.g. invoking simp on the goal
  6751 
  6752         [| P (f x); y = x; f x = f y |] ==> Q
  6753 
  6754        now gives rise to the infinite reduction sequence
  6755 
  6756         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  6757 
  6758        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  6759        kind of problem.
  6760 
  6761     -- Tactics combining classical reasoner and simplification (such as auto)
  6762        are also affected by this change, because many of them rely on
  6763        simp. They may sometimes diverge as well or yield a different numbers
  6764        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  6765        in case of problems. Sometimes subsequent calls to the classical
  6766        reasoner will fail because a preceeding call to the simplifier too
  6767        eagerly simplified the goal, e.g. deleted redundant premises.
  6768 
  6769   - The simplifier trace now shows the names of the applied rewrite rules
  6770 
  6771   - You can limit the number of recursive invocations of the simplifier
  6772     during conditional rewriting (where the simplifie tries to solve the
  6773     conditions before applying the rewrite rule):
  6774     ML "simp_depth_limit := n"
  6775     where n is an integer. Thus you can force termination where previously
  6776     the simplifier would diverge.
  6777 
  6778   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  6779 
  6780   - No longer aborts on failed congruence proof.  Instead, the
  6781     congruence is ignored.
  6782 
  6783 * Pure: New generic framework for extracting programs from constructive
  6784   proofs. See HOL/Extraction.thy for an example instantiation, as well
  6785   as HOL/Extraction for some case studies.
  6786 
  6787 * Pure: The main goal of the proof state is no longer shown by default, only
  6788 the subgoals. This behaviour is controlled by a new flag.
  6789    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  6790 (ML: Proof.show_main_goal).
  6791 
  6792 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  6793 rules whose conclusion matches subgoal 1:
  6794       PG menu: Isabelle/Isar -> Show me -> matching rules
  6795 The rules are ordered by how closely they match the subgoal.
  6796 In particular, rules that solve a subgoal outright are displayed first
  6797 (or rather last, the way they are printed).
  6798 (ML: ProofGeneral.print_intros())
  6799 
  6800 * Pure: New flag trace_unify_fail causes unification to print
  6801 diagnostic information (PG: in trace buffer) when it fails. This is
  6802 useful for figuring out why single step proofs like rule, erule or
  6803 assumption failed.
  6804 
  6805 * Pure: Locale specifications now produce predicate definitions
  6806 according to the body of text (covering assumptions modulo local
  6807 definitions); predicate "loc_axioms" covers newly introduced text,
  6808 while "loc" is cumulative wrt. all included locale expressions; the
  6809 latter view is presented only on export into the global theory
  6810 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  6811 on the old view without predicates;
  6812 
  6813 * Pure: predefined locales "var" and "struct" are useful for sharing
  6814 parameters (as in CASL, for example); just specify something like
  6815 ``var x + var y + struct M'' as import;
  6816 
  6817 * Pure: improved thms_containing: proper indexing of facts instead of
  6818 raw theorems; check validity of results wrt. current name space;
  6819 include local facts of proof configuration (also covers active
  6820 locales), cover fixed variables in index; may use "_" in term
  6821 specification; an optional limit for the number of printed facts may
  6822 be given (the default is 40);
  6823 
  6824 * Pure: disallow duplicate fact bindings within new-style theory files
  6825 (batch-mode only);
  6826 
  6827 * Provers: improved induct method: assumptions introduced by case
  6828 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6829 the goal statement); "foo" still refers to all facts collectively;
  6830 
  6831 * Provers: the function blast.overloaded has been removed: all constants
  6832 are regarded as potentially overloaded, which improves robustness in exchange
  6833 for slight decrease in efficiency;
  6834 
  6835 * Provers/linorder: New generic prover for transitivity reasoning over
  6836 linear orders.  Note: this prover is not efficient!
  6837 
  6838 * Isar: preview of problems to finish 'show' now produce an error
  6839 rather than just a warning (in interactive mode);
  6840 
  6841 
  6842 *** HOL ***
  6843 
  6844 * arith(_tac)
  6845 
  6846  - Produces a counter example if it cannot prove a goal.
  6847    Note that the counter example may be spurious if the goal is not a formula
  6848    of quantifier-free linear arithmetic.
  6849    In ProofGeneral the counter example appears in the trace buffer.
  6850 
  6851  - Knows about div k and mod k where k is a numeral of type nat or int.
  6852 
  6853  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6854    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6855    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6856 
  6857 * simp's arithmetic capabilities have been enhanced a bit: it now
  6858 takes ~= in premises into account (by performing a case split);
  6859 
  6860 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6861 are distributed over a sum of terms;
  6862 
  6863 * New tactic "trans_tac" and method "trans" instantiate
  6864 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6865 "<=", "<" and "=").
  6866 
  6867 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6868 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6869 
  6870 * 'typedef' command has new option "open" to suppress the set
  6871 definition;
  6872 
  6873 * functions Min and Max on finite sets have been introduced (theory
  6874 Finite_Set);
  6875 
  6876 * attribute [symmetric] now works for relations as well; it turns
  6877 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6878 
  6879 * induct over a !!-quantified statement (say !!x1..xn):
  6880   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6881 
  6882 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6883 %x. None. Warning: empty_def now refers to the previously hidden definition
  6884 of the empty set.
  6885 
  6886 * Algebra: formalization of classical algebra.  Intended as base for
  6887 any algebraic development in Isabelle.  Currently covers group theory
  6888 (up to Sylow's theorem) and ring theory (Universal Property of
  6889 Univariate Polynomials).  Contributions welcome;
  6890 
  6891 * GroupTheory: deleted, since its material has been moved to Algebra;
  6892 
  6893 * Complex: new directory of the complex numbers with numeric constants,
  6894 nonstandard complex numbers, and some complex analysis, standard and
  6895 nonstandard (Jacques Fleuriot);
  6896 
  6897 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6898 
  6899 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6900 Fleuriot);
  6901 
  6902 * Real/HahnBanach: updated and adapted to locales;
  6903 
  6904 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6905 Gray and Kramer);
  6906 
  6907 * UNITY: added the Meier-Sanders theory of progress sets;
  6908 
  6909 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6910 as abstract algorithms, instantiated to the JVM;
  6911 
  6912 * Bali: Java source language formalization. Type system, operational
  6913 semantics, axiomatic semantics. Supported language features:
  6914 classes, interfaces, objects,virtual methods, static methods,
  6915 static/instance fields, arrays, access modifiers, definite
  6916 assignment, exceptions.
  6917 
  6918 
  6919 *** ZF ***
  6920 
  6921 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6922 universe, etc.);
  6923 
  6924 * Main ZF: virtually all theories converted to new-style format;
  6925 
  6926 
  6927 *** ML ***
  6928 
  6929 * Pure: Tactic.prove provides sane interface for internal proofs;
  6930 omits the infamous "standard" operation, so this is more appropriate
  6931 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6932 
  6933 * Pure: improved error reporting of simprocs;
  6934 
  6935 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6936 up simprocs;
  6937 
  6938 
  6939 *** Document preparation ***
  6940 
  6941 * uses \par instead of \\ for line breaks in theory text. This may
  6942 shift some page breaks in large documents. To get the old behaviour
  6943 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6944 
  6945 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6946 other packages
  6947 
  6948 * \<euro> now needs package babel/greek instead of marvosym (which
  6949 broke \Rightarrow)
  6950 
  6951 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6952 textcomp package)
  6953 
  6954 
  6955 
  6956 New in Isabelle2002 (March 2002)
  6957 --------------------------------
  6958 
  6959 *** Document preparation ***
  6960 
  6961 * greatly simplified document preparation setup, including more
  6962 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6963 instructive isatool mkdir; users should basically be able to get
  6964 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6965 users may run a separate document processing stage manually like this:
  6966 "isatool usedir -D output HOL Test && isatool document Test/output";
  6967 
  6968 * theory dependency graph may now be incorporated into documents;
  6969 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6970 with \includegraphics of LaTeX;
  6971 
  6972 * proper spacing of consecutive markup elements, especially text
  6973 blocks after section headings;
  6974 
  6975 * support bold style (for single symbols only), input syntax is like
  6976 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6977 
  6978 * \<bullet> is now output as bold \cdot by default, which looks much
  6979 better in printed text;
  6980 
  6981 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6982 note that these symbols are currently unavailable in Proof General /
  6983 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6984 
  6985 * isatool latex no longer depends on changed TEXINPUTS, instead
  6986 isatool document copies the Isabelle style files to the target
  6987 location;
  6988 
  6989 
  6990 *** Isar ***
  6991 
  6992 * Pure/Provers: improved proof by cases and induction;
  6993   - 'case' command admits impromptu naming of parameters (such as
  6994     "case (Suc n)");
  6995   - 'induct' method divinates rule instantiation from the inductive
  6996     claim; no longer requires excessive ?P bindings for proper
  6997     instantiation of cases;
  6998   - 'induct' method properly enumerates all possibilities of set/type
  6999     rules; as a consequence facts may be also passed through *type*
  7000     rules without further ado;
  7001   - 'induct' method now derives symbolic cases from the *rulified*
  7002     rule (before it used to rulify cases stemming from the internal
  7003     atomized version); this means that the context of a non-atomic
  7004     statement becomes is included in the hypothesis, avoiding the
  7005     slightly cumbersome show "PROP ?case" form;
  7006   - 'induct' may now use elim-style induction rules without chaining
  7007     facts, using ``missing'' premises from the goal state; this allows
  7008     rules stemming from inductive sets to be applied in unstructured
  7009     scripts, while still benefitting from proper handling of non-atomic
  7010     statements; NB: major inductive premises need to be put first, all
  7011     the rest of the goal is passed through the induction;
  7012   - 'induct' proper support for mutual induction involving non-atomic
  7013     rule statements (uses the new concept of simultaneous goals, see
  7014     below);
  7015   - append all possible rule selections, but only use the first
  7016     success (no backtracking);
  7017   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  7018   - undeclared rule case names default to numbers 1, 2, 3, ...;
  7019   - added 'print_induct_rules' (covered by help item in recent Proof
  7020     General versions);
  7021   - moved induct/cases attributes to Pure, methods to Provers;
  7022   - generic method setup instantiated for FOL and HOL;
  7023 
  7024 * Pure: support multiple simultaneous goal statements, for example
  7025 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  7026 meta-level mechanism, this acts as if several individual goals had
  7027 been stated separately; in particular common proof methods need to be
  7028 repeated in order to cover all claims; note that a single elimination
  7029 step is *not* sufficient to establish the two conjunctions, so this
  7030 fails:
  7031 
  7032   assume "A & B" then have A and B ..   (*".." fails*)
  7033 
  7034 better use "obtain" in situations as above; alternative refer to
  7035 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  7036 
  7037 * Pure: proper integration with ``locales''; unlike the original
  7038 version by Florian Kammller, Isar locales package high-level proof
  7039 contexts rather than raw logical ones (e.g. we admit to include
  7040 attributes everywhere); operations on locales include merge and
  7041 rename; support for implicit arguments (``structures''); simultaneous
  7042 type-inference over imports and text; see also HOL/ex/Locales.thy for
  7043 some examples;
  7044 
  7045 * Pure: the following commands have been ``localized'', supporting a
  7046 target locale specification "(in name)": 'lemma', 'theorem',
  7047 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  7048 stored both within the locale and at the theory level (exported and
  7049 qualified by the locale name);
  7050 
  7051 * Pure: theory goals may now be specified in ``long'' form, with
  7052 ad-hoc contexts consisting of arbitrary locale elements. for example
  7053 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  7054 definitions may be given, too); the result is a meta-level rule with
  7055 the context elements being discharged in the obvious way;
  7056 
  7057 * Pure: new proof command 'using' allows to augment currently used
  7058 facts after a goal statement ('using' is syntactically analogous to
  7059 'apply', but acts on the goal's facts only); this allows chained facts
  7060 to be separated into parts given before and after a claim, as in
  7061 ``from a and b have C using d and e <proof>'';
  7062 
  7063 * Pure: renamed "antecedent" case to "rule_context";
  7064 
  7065 * Pure: new 'judgment' command records explicit information about the
  7066 object-logic embedding (used by several tools internally); no longer
  7067 use hard-wired "Trueprop";
  7068 
  7069 * Pure: added 'corollary' command;
  7070 
  7071 * Pure: fixed 'token_translation' command;
  7072 
  7073 * Pure: removed obsolete 'exported' attribute;
  7074 
  7075 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  7076 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  7077 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  7078 
  7079 * Pure: method 'atomize' presents local goal premises as object-level
  7080 statements (atomic meta-level propositions); setup controlled via
  7081 rewrite rules declarations of 'atomize' attribute; example
  7082 application: 'induct' method with proper rule statements in improper
  7083 proof *scripts*;
  7084 
  7085 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  7086 now consider the syntactic context of assumptions, giving a better
  7087 chance to get type-inference of the arguments right (this is
  7088 especially important for locales);
  7089 
  7090 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  7091 mode;
  7092 
  7093 * Pure/obtain: the formal conclusion "thesis", being marked as
  7094 ``internal'', may no longer be reference directly in the text;
  7095 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  7096 situations;
  7097 
  7098 * Pure: generic 'sym' attribute which declares a rule both as pure
  7099 'elim?' and for the 'symmetric' operation;
  7100 
  7101 * Pure: marginal comments ``--'' may now occur just anywhere in the
  7102 text; the fixed correlation with particular command syntax has been
  7103 discontinued;
  7104 
  7105 * Pure: new method 'rules' is particularly well-suited for proof
  7106 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  7107 but often produces more compact proof terms with less detours;
  7108 
  7109 * Pure/Provers/classical: simplified integration with pure rule
  7110 attributes and methods; the classical "intro?/elim?/dest?"
  7111 declarations coincide with the pure ones; the "rule" method no longer
  7112 includes classically swapped intros; "intro" and "elim" methods no
  7113 longer pick rules from the context; also got rid of ML declarations
  7114 AddXIs/AddXEs/AddXDs; all of this has some potential for
  7115 INCOMPATIBILITY;
  7116 
  7117 * Provers/classical: attribute 'swapped' produces classical inversions
  7118 of introduction rules;
  7119 
  7120 * Provers/simplifier: 'simplified' attribute may refer to explicit
  7121 rules instead of full simplifier context; 'iff' attribute handles
  7122 conditional rules;
  7123 
  7124 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  7125 
  7126 * HOL: 'recdef' now fails on unfinished automated proofs, use
  7127 "(permissive)" option to recover old behavior;
  7128 
  7129 * HOL: 'inductive' no longer features separate (collective) attributes
  7130 for 'intros' (was found too confusing);
  7131 
  7132 * HOL: properly declared induction rules less_induct and
  7133 wf_induct_rule;
  7134 
  7135 
  7136 *** HOL ***
  7137 
  7138 * HOL: moved over to sane numeral syntax; the new policy is as
  7139 follows:
  7140 
  7141   - 0 and 1 are polymorphic constants, which are defined on any
  7142   numeric type (nat, int, real etc.);
  7143 
  7144   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  7145   binary representation internally;
  7146 
  7147   - type nat has special constructor Suc, and generally prefers Suc 0
  7148   over 1::nat and Suc (Suc 0) over 2::nat;
  7149 
  7150 This change may cause significant problems of INCOMPATIBILITY; here
  7151 are some hints on converting existing sources:
  7152 
  7153   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  7154   entities, so expressions involving "-" (unary or binary minus) need
  7155   to be spaced properly;
  7156 
  7157   - existing occurrences of "1" may need to be constraint "1::nat" or
  7158   even replaced by Suc 0; similar for old "2";
  7159 
  7160   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  7161 
  7162   - remove all special provisions on numerals in proofs;
  7163 
  7164 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  7165 representation (depends on bin_arith_simps in the default context);
  7166 
  7167 * HOL: symbolic syntax for x^2 (numeral 2);
  7168 
  7169 * HOL: the class of all HOL types is now called "type" rather than
  7170 "term"; INCOMPATIBILITY, need to adapt references to this type class
  7171 in axclass/classes, instance/arities, and (usually rare) occurrences
  7172 in typings (of consts etc.); internally the class is called
  7173 "HOL.type", ML programs should refer to HOLogic.typeS;
  7174 
  7175 * HOL/record package improvements:
  7176   - new derived operations "fields" to build a partial record section,
  7177     "extend" to promote a fixed record to a record scheme, and
  7178     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  7179     declared as simp by default;
  7180   - shared operations ("more", "fields", etc.) now need to be always
  7181     qualified) --- potential INCOMPATIBILITY;
  7182   - removed "make_scheme" operations (use "make" with "extend") --
  7183     INCOMPATIBILITY;
  7184   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  7185   - provides cases/induct rules for use with corresponding Isar
  7186     methods (for concrete records, record schemes, concrete more
  7187     parts, and schematic more parts -- in that order);
  7188   - internal definitions directly based on a light-weight abstract
  7189     theory of product types over typedef rather than datatype;
  7190 
  7191 * HOL: generic code generator for generating executable ML code from
  7192 specifications; specific support for HOL constructs such as inductive
  7193 datatypes and sets, as well as recursive functions; can be invoked
  7194 via 'generate_code' theory section;
  7195 
  7196 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  7197 
  7198 * HOL: consolidated and renamed several theories.  In particular:
  7199         Ord.thy has been absorbed into HOL.thy
  7200         String.thy has been absorbed into List.thy
  7201 
  7202 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  7203 (beware of argument permutation!);
  7204 
  7205 * HOL: linorder_less_split superseded by linorder_cases;
  7206 
  7207 * HOL/List: "nodups" renamed to "distinct";
  7208 
  7209 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  7210 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  7211   - Ex_def has changed, now need to use some_eq_ex
  7212 
  7213 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  7214 in this (rare) case use:
  7215 
  7216   delSWrapper "split_all_tac"
  7217   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  7218 
  7219 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  7220 MAY FAIL;
  7221 
  7222 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  7223 Isabelle's type classes, ^ on functions and relations has too general
  7224 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  7225 necessary to attach explicit type constraints;
  7226 
  7227 * HOL/Relation: the prefix name of the infix "O" has been changed from
  7228 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  7229 renamed accordingly (eg "compI" -> "rel_compI").
  7230 
  7231 * HOL: syntax translations now work properly with numerals and records
  7232 expressions;
  7233 
  7234 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  7235 of "lam" -- INCOMPATIBILITY;
  7236 
  7237 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  7238 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  7239 renamed "Product_Type.unit";
  7240 
  7241 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  7242 
  7243 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  7244 the "cases" method);
  7245 
  7246 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  7247 Florian Kammller);
  7248 
  7249 * HOL/IMP: updated and converted to new-style theory format; several
  7250 parts turned into readable document, with proper Isar proof texts and
  7251 some explanations (by Gerwin Klein);
  7252 
  7253 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  7254 
  7255 * HOL-Hyperreal is now a logic image;
  7256 
  7257 
  7258 *** HOLCF ***
  7259 
  7260 * Isar: consts/constdefs supports mixfix syntax for continuous
  7261 operations;
  7262 
  7263 * Isar: domain package adapted to new-style theory format, e.g. see
  7264 HOLCF/ex/Dnat.thy;
  7265 
  7266 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  7267 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  7268 lift.induct_tac, always use UU instead of Undef;
  7269 
  7270 * HOLCF/IMP: updated and converted to new-style theory;
  7271 
  7272 
  7273 *** ZF ***
  7274 
  7275 * Isar: proper integration of logic-specific tools and packages,
  7276 including theory commands '(co)inductive', '(co)datatype',
  7277 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  7278 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7279 
  7280 * theory Main no longer includes AC; for the Axiom of Choice, base
  7281 your theory on Main_ZFC;
  7282 
  7283 * the integer library now covers quotients and remainders, with many
  7284 laws relating division to addition, multiplication, etc.;
  7285 
  7286 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7287 typeless version of the formalism;
  7288 
  7289 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7290 format;
  7291 
  7292 * ZF/Induct: new directory for examples of inductive definitions,
  7293 including theory Multiset for multiset orderings; converted to
  7294 new-style theory format;
  7295 
  7296 * ZF: many new theorems about lists, ordinals, etc.;
  7297 
  7298 
  7299 *** General ***
  7300 
  7301 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7302 variable proof controls level of detail: 0 = no proofs (only oracle
  7303 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7304 also ref manual for further ML interfaces;
  7305 
  7306 * Pure/axclass: removed obsolete ML interface
  7307 goal_subclass/goal_arity;
  7308 
  7309 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7310 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7311 separate tokens, so expressions involving minus need to be spaced
  7312 properly;
  7313 
  7314 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7315 rather than "infixl" or "infixr";
  7316 
  7317 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7318 sort constraint specifications in type inference; e.g. "x::_::foo"
  7319 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7320 type variable);
  7321 
  7322 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7323 control output of nested => (types); the default behavior is
  7324 "type_brackets";
  7325 
  7326 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7327 tokens into AST constants;
  7328 
  7329 * Pure/syntax: prefer later declarations of translations and print
  7330 translation functions; potential INCOMPATIBILITY: need to reverse
  7331 multiple declarations for same syntax element constant;
  7332 
  7333 * Pure/show_hyps reset by default (in accordance to existing Isar
  7334 practice);
  7335 
  7336 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7337 addSafter;
  7338 
  7339 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7340 as well;
  7341 
  7342 * system: tested support for MacOS X; should be able to get Isabelle +
  7343 Proof General to work in a plain Terminal after installing Poly/ML
  7344 (e.g. from the Isabelle distribution area) and GNU bash alone
  7345 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7346 support requires further installations, e.g. from
  7347 http://fink.sourceforge.net/);
  7348 
  7349 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7350 
  7351 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7352 of 40 MB), cf. ML_OPTIONS;
  7353 
  7354 * system: Proof General keywords specification is now part of the
  7355 Isabelle distribution (see etc/isar-keywords.el);
  7356 
  7357 * system: support for persistent Proof General sessions (refrain from
  7358 outdating all loaded theories on startup); user may create writable
  7359 logic images like this: ``isabelle -q HOL Test'';
  7360 
  7361 * system: smart selection of Isabelle process versus Isabelle
  7362 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7363 run both "isabelle" and "Isabelle" even if file names are badly
  7364 damaged (executable inspects the case of the first letter of its own
  7365 name); added separate "isabelle-process" and "isabelle-interface";
  7366 
  7367 * system: refrain from any attempt at filtering input streams; no
  7368 longer support ``8bit'' encoding of old isabelle font, instead proper
  7369 iso-latin characters may now be used; the related isatools
  7370 "symbolinput" and "nonascii" have disappeared as well;
  7371 
  7372 * system: removed old "xterm" interface (the print modes "xterm" and
  7373 "xterm_color" are still available for direct use in a suitable
  7374 terminal);
  7375 
  7376 
  7377 
  7378 New in Isabelle99-2 (February 2001)
  7379 -----------------------------------
  7380 
  7381 *** Overview of INCOMPATIBILITIES ***
  7382 
  7383 * HOL: please note that theories in the Library and elsewhere often use the
  7384 new-style (Isar) format; to refer to their theorems in an ML script you must
  7385 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7386 
  7387 * HOL: inductive package no longer splits induction rule aggressively,
  7388 but only as far as specified by the introductions given; the old
  7389 format may be recovered via ML function complete_split_rule or attribute
  7390 'split_rule (complete)';
  7391 
  7392 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7393 gfp_Tarski to gfp_unfold;
  7394 
  7395 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7396 
  7397 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7398 relation); infix "^^" has been renamed "``"; infix "``" has been
  7399 renamed "`"; "univalent" has been renamed "single_valued";
  7400 
  7401 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7402 operation;
  7403 
  7404 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7405 
  7406 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7407 
  7408 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7409 consequence, it is no longer monotonic wrt. the local goal context
  7410 (which is now passed through the inductive cases);
  7411 
  7412 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7413 \<gg> to \<ggreater>;
  7414 
  7415 
  7416 *** Document preparation ***
  7417 
  7418 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7419 available: are "it" for near math-mode best-style output, "sl" for
  7420 slanted text style, and "tt" for plain type-writer; if no
  7421 \isabellestyle command is given, output is according to slanted
  7422 type-writer);
  7423 
  7424 * support sub/super scripts (for single symbols only), input syntax is
  7425 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7426 
  7427 * some more standard symbols; see Appendix A of the system manual for
  7428 the complete list of symbols defined in isabellesym.sty;
  7429 
  7430 * improved isabelle style files; more abstract symbol implementation
  7431 (should now use \isamath{...} and \isatext{...} in custom symbol
  7432 definitions);
  7433 
  7434 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  7435 state; Note that presentation of goal states does not conform to
  7436 actual human-readable proof documents.  Please do not include goal
  7437 states into document output unless you really know what you are doing!
  7438 
  7439 * proper indentation of antiquoted output with proportional LaTeX
  7440 fonts;
  7441 
  7442 * no_document ML operator temporarily disables LaTeX document
  7443 generation;
  7444 
  7445 * isatool unsymbolize tunes sources for plain ASCII communication;
  7446 
  7447 
  7448 *** Isar ***
  7449 
  7450 * Pure: Isar now suffers initial goal statements to contain unbound
  7451 schematic variables (this does not conform to actual readable proof
  7452 documents, due to unpredictable outcome and non-compositional proof
  7453 checking); users who know what they are doing may use schematic goals
  7454 for Prolog-style synthesis of proven results;
  7455 
  7456 * Pure: assumption method (an implicit finishing) now handles actual
  7457 rules as well;
  7458 
  7459 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  7460 initial goal, declare "that" only as Pure intro (only for single
  7461 steps); the "that" rule assumption may now be involved in implicit
  7462 finishing, thus ".." becomes a feasible for trivial obtains;
  7463 
  7464 * Pure: default proof step now includes 'intro_classes'; thus trivial
  7465 instance proofs may be performed by "..";
  7466 
  7467 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  7468 statements as well;
  7469 
  7470 * Pure: more robust selection of calculational rules;
  7471 
  7472 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  7473 rule (as well as the assumption rule);
  7474 
  7475 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  7476 lemmas, using the graph browser tool;
  7477 
  7478 * Pure: predict failure of "show" in interactive mode;
  7479 
  7480 * Pure: 'thms_containing' now takes actual terms as arguments;
  7481 
  7482 * HOL: improved method 'induct' --- now handles non-atomic goals
  7483 (potential INCOMPATIBILITY); tuned error handling;
  7484 
  7485 * HOL: cases and induct rules now provide explicit hints about the
  7486 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  7487 any remaining facts are inserted into the goal verbatim;
  7488 
  7489 * HOL: local contexts (aka cases) may now contain term bindings as
  7490 well; the 'cases' and 'induct' methods new provide a ?case binding for
  7491 the result to be shown in each case;
  7492 
  7493 * HOL: added 'recdef_tc' command;
  7494 
  7495 * isatool convert assists in eliminating legacy ML scripts;
  7496 
  7497 
  7498 *** HOL ***
  7499 
  7500 * HOL/Library: a collection of generic theories to be used together
  7501 with main HOL; the theory loader path already includes this directory
  7502 by default; the following existing theories have been moved here:
  7503 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  7504 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  7505 
  7506 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  7507 modelling and verification task performed in Isabelle/HOL +
  7508 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  7509 
  7510 * HOL/Algebra: special summation operator SUM no longer exists, it has
  7511 been replaced by setsum; infix 'assoc' now has priority 50 (like
  7512 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  7513 'domain', this makes the theory consistent with mathematical
  7514 literature;
  7515 
  7516 * HOL basics: added overloaded operations "inverse" and "divide"
  7517 (infix "/"), syntax for generic "abs" operation, generic summation
  7518 operator \<Sum>;
  7519 
  7520 * HOL/typedef: simplified package, provide more useful rules (see also
  7521 HOL/subset.thy);
  7522 
  7523 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  7524 now expressed as a proper nested rule (old-style tactic scripts may
  7525 require atomize_strip_tac to cope with non-atomic premises);
  7526 
  7527 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  7528 to "split_conv" (old name still available for compatibility);
  7529 
  7530 * HOL: improved concrete syntax for strings (e.g. allows translation
  7531 rules with string literals);
  7532 
  7533 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  7534  and Fleuriot's mechanization of analysis, including the transcendental
  7535  functions for the reals;
  7536 
  7537 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  7538 
  7539 
  7540 *** CTT ***
  7541 
  7542 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  7543 "lam" is displayed as TWO lambda-symbols
  7544 
  7545 * CTT: theory Main now available, containing everything (that is, Bool
  7546 and Arith);
  7547 
  7548 
  7549 *** General ***
  7550 
  7551 * Pure: the Simplifier has been implemented properly as a derived rule
  7552 outside of the actual kernel (at last!); the overall performance
  7553 penalty in practical applications is about 50%, while reliability of
  7554 the Isabelle inference kernel has been greatly improved;
  7555 
  7556 * print modes "brackets" and "no_brackets" control output of nested =>
  7557 (types) and ==> (props); the default behaviour is "brackets";
  7558 
  7559 * Provers: fast_tac (and friends) now handle actual object-logic rules
  7560 as assumptions as well;
  7561 
  7562 * system: support Poly/ML 4.0;
  7563 
  7564 * system: isatool install handles KDE version 1 or 2;
  7565 
  7566 
  7567 
  7568 New in Isabelle99-1 (October 2000)
  7569 ----------------------------------
  7570 
  7571 *** Overview of INCOMPATIBILITIES ***
  7572 
  7573 * HOL: simplification of natural numbers is much changed; to partly
  7574 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  7575 issue the following ML commands:
  7576 
  7577   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  7578   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  7579 
  7580 * HOL: simplification no longer dives into case-expressions; this is
  7581 controlled by "t.weak_case_cong" for each datatype t;
  7582 
  7583 * HOL: nat_less_induct renamed to less_induct;
  7584 
  7585 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  7586 fixsome to patch .thy and .ML sources automatically;
  7587 
  7588   select_equality  -> some_equality
  7589   select_eq_Ex     -> some_eq_ex
  7590   selectI2EX       -> someI2_ex
  7591   selectI2         -> someI2
  7592   selectI          -> someI
  7593   select1_equality -> some1_equality
  7594   Eps_sym_eq       -> some_sym_eq_trivial
  7595   Eps_eq           -> some_eq_trivial
  7596 
  7597 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  7598 
  7599 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  7600 instead);
  7601 
  7602 * HOL: the recursion equations generated by 'recdef' are now called
  7603 f.simps instead of f.rules;
  7604 
  7605 * HOL: qed_spec_mp now also handles bounded ALL as well;
  7606 
  7607 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  7608 sometimes be needed;
  7609 
  7610 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  7611 
  7612 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  7613 
  7614 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  7615 product is now "<*>" instead of "Times"; the lexicographic product is
  7616 now "<*lex*>" instead of "**";
  7617 
  7618 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  7619 of main HOL, but was unused); better use HOL's datatype package;
  7620 
  7621 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  7622 the old syntax may be recovered as follows:
  7623 
  7624   syntax (symbols)
  7625     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  7626       (infixl "\\<oplus>" 100)
  7627 
  7628 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7629 
  7630 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  7631 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  7632 internally;
  7633 
  7634 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  7635 changed from A/r to A//r;
  7636 
  7637 * ZF: new treatment of arithmetic (nat & int) may break some old
  7638 proofs;
  7639 
  7640 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  7641 rulify -> rule_format, elimify -> elim_format, ...);
  7642 
  7643 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7644 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  7645 should have to change intro!! to intro? only); replaced "delrule" by
  7646 "rule del";
  7647 
  7648 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  7649 
  7650 * Provers: strengthened force_tac by using new first_best_tac;
  7651 
  7652 * LaTeX document preparation: several changes of isabelle.sty (see
  7653 lib/texinputs);
  7654 
  7655 
  7656 *** Document preparation ***
  7657 
  7658 * formal comments (text blocks etc.) in new-style theories may now
  7659 contain antiquotations of thm/prop/term/typ/text to be presented
  7660 according to latex print mode; concrete syntax is like this:
  7661 @{term[show_types] "f(x) = a + x"};
  7662 
  7663 * isatool mkdir provides easy setup of Isabelle session directories,
  7664 including proper document sources;
  7665 
  7666 * generated LaTeX sources are now deleted after successful run
  7667 (isatool document -c); may retain a copy somewhere else via -D option
  7668 of isatool usedir;
  7669 
  7670 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  7671 style files, achieving self-contained LaTeX sources and simplifying
  7672 LaTeX debugging;
  7673 
  7674 * old-style theories now produce (crude) LaTeX output as well;
  7675 
  7676 * browser info session directories are now self-contained (may be put
  7677 on WWW server seperately); improved graphs of nested sessions; removed
  7678 graph for 'all sessions';
  7679 
  7680 * several improvements in isabelle style files; \isabellestyle{it}
  7681 produces fake math mode output; \isamarkupheader is now \section by
  7682 default; see lib/texinputs/isabelle.sty etc.;
  7683 
  7684 
  7685 *** Isar ***
  7686 
  7687 * Isar/Pure: local results and corresponding term bindings are now
  7688 subject to Hindley-Milner polymorphism (similar to ML); this
  7689 accommodates incremental type-inference very nicely;
  7690 
  7691 * Isar/Pure: new derived language element 'obtain' supports
  7692 generalized existence reasoning;
  7693 
  7694 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  7695 support accumulation of results, without applying any rules yet;
  7696 useful to collect intermediate results without explicit name
  7697 references, and for use with transitivity rules with more than 2
  7698 premises;
  7699 
  7700 * Isar/Pure: scalable support for case-analysis type proofs: new
  7701 'case' language element refers to local contexts symbolically, as
  7702 produced by certain proof methods; internally, case names are attached
  7703 to theorems as "tags";
  7704 
  7705 * Isar/Pure: theory command 'hide' removes declarations from
  7706 class/type/const name spaces;
  7707 
  7708 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  7709 indicate potential overloading;
  7710 
  7711 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  7712 
  7713 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  7714 "{a,b,c}" instead of {a,b,c};
  7715 
  7716 * Isar/Pure now provides its own version of intro/elim/dest
  7717 attributes; useful for building new logics, but beware of confusion
  7718 with the version in Provers/classical;
  7719 
  7720 * Isar/Pure: the local context of (non-atomic) goals is provided via
  7721 case name 'antecedent';
  7722 
  7723 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  7724 to the current context is now done automatically);
  7725 
  7726 * Isar/Pure: theory command 'method_setup' provides a simple interface
  7727 for definining proof methods in ML;
  7728 
  7729 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7730 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  7731 most cases, one should have to change intro!! to intro? only);
  7732 replaced "delrule" by "rule del";
  7733 
  7734 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  7735 'symmetric' attribute (the latter supercedes [RS sym]);
  7736 
  7737 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  7738 method modifier); 'simp' method: 'only:' modifier removes loopers as
  7739 well (including splits);
  7740 
  7741 * Isar/Provers: Simplifier and Classical methods now support all kind
  7742 of modifiers used in the past, including 'cong', 'iff', etc.
  7743 
  7744 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  7745 of Simplifier and Classical reasoner);
  7746 
  7747 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  7748 now support named cases; major packages (inductive, datatype, primrec,
  7749 recdef) support case names and properly name parameters;
  7750 
  7751 * Isar/HOL: new transitivity rules for substitution in inequalities --
  7752 monotonicity conditions are extracted to be proven at end of
  7753 calculations;
  7754 
  7755 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  7756 method anyway;
  7757 
  7758 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  7759 split_if split_if_asm; datatype package provides theorems foo.splits =
  7760 foo.split foo.split_asm for each datatype;
  7761 
  7762 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  7763 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  7764 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  7765 use "(cases (simplified))" method in proper proof texts);
  7766 
  7767 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  7768 
  7769 * Isar: names of theorems etc. may be natural numbers as well;
  7770 
  7771 * Isar: 'pr' command: optional arguments for goals_limit and
  7772 ProofContext.prems_limit; no longer prints theory contexts, but only
  7773 proof states;
  7774 
  7775 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  7776 additional print modes to be specified; e.g. "pr(latex)" will print
  7777 proof state according to the Isabelle LaTeX style;
  7778 
  7779 * Isar: improved support for emulating tactic scripts, including proof
  7780 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  7781 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  7782 (for HOL datatypes);
  7783 
  7784 * Isar: simplified (more robust) goal selection of proof methods: 1st
  7785 goal, all goals, or explicit goal specifier (tactic emulation); thus
  7786 'proof method scripts' have to be in depth-first order;
  7787 
  7788 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  7789 
  7790 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  7791 should instead use individual commands for printing items
  7792 (print_commands, print_methods etc.);
  7793 
  7794 * Isar: added 'nothing' --- the empty list of theorems;
  7795 
  7796 
  7797 *** HOL ***
  7798 
  7799 * HOL/MicroJava: formalization of a fragment of Java, together with a
  7800 corresponding virtual machine and a specification of its bytecode
  7801 verifier and a lightweight bytecode verifier, including proofs of
  7802 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  7803 Cornelia Pusch (see also the homepage of project Bali at
  7804 http://isabelle.in.tum.de/Bali/);
  7805 
  7806 * HOL/Algebra: new theory of rings and univariate polynomials, by
  7807 Clemens Ballarin;
  7808 
  7809 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  7810 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  7811 Rasmussen;
  7812 
  7813 * HOL/Lattice: fundamental concepts of lattice theory and order
  7814 structures, including duals, properties of bounds versus algebraic
  7815 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  7816 Theorem for complete lattices etc.; may also serve as a demonstration
  7817 for abstract algebraic reasoning using axiomatic type classes, and
  7818 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  7819 
  7820 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  7821 von Oheimb;
  7822 
  7823 * HOL/IMPP: extension of IMP with local variables and mutually
  7824 recursive procedures, by David von Oheimb;
  7825 
  7826 * HOL/Lambda: converted into new-style theory and document;
  7827 
  7828 * HOL/ex/Multiquote: example of multiple nested quotations and
  7829 anti-quotations -- basically a generalized version of de-Bruijn
  7830 representation; very useful in avoiding lifting of operations;
  7831 
  7832 * HOL/record: added general record equality rule to simpset; fixed
  7833 select-update simplification procedure to handle extended records as
  7834 well; admit "r" as field name;
  7835 
  7836 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  7837 other numeric types and also as the identity of groups, rings, etc.;
  7838 
  7839 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  7840 Types nat and int belong to this axclass;
  7841 
  7842 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  7843    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  7844    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  7845   two terms #m*u and #n*u are replaced by #(m+n)*u
  7846     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  7847   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  7848     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  7849 
  7850 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  7851 powerful prover for predicate logic but knows nothing of clasets; see
  7852 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  7853 
  7854 * HOL: new version of "case_tac" subsumes both boolean case split and
  7855 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  7856 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  7857 
  7858 * HOL: simplification no longer dives into case-expressions: only the
  7859 selector expression is simplified, but not the remaining arms; to
  7860 enable full simplification of case-expressions for datatype t, you may
  7861 remove t.weak_case_cong from the simpset, either globally (Delcongs
  7862 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  7863 
  7864 * HOL/recdef: the recursion equations generated by 'recdef' for
  7865 function 'f' are now called f.simps instead of f.rules; if all
  7866 termination conditions are proved automatically, these simplification
  7867 rules are added to the simpset, as in primrec; rules may be named
  7868 individually as well, resulting in a separate list of theorems for
  7869 each equation;
  7870 
  7871 * HOL/While is a new theory that provides a while-combinator. It
  7872 permits the definition of tail-recursive functions without the
  7873 provision of a termination measure. The latter is necessary once the
  7874 invariant proof rule for while is applied.
  7875 
  7876 * HOL: new (overloaded) notation for the set of elements below/above
  7877 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7878 
  7879 * HOL: theorems impI, allI, ballI bound as "strip";
  7880 
  7881 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7882 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7883 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7884 
  7885 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7886 
  7887 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7888 main HOL, but was unused);
  7889 
  7890 * HOL: fewer consts declared as global (e.g. have to refer to
  7891 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7892 
  7893 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7894 in case of overlap with user translations (e.g. judgements over
  7895 tuples); (note that the underlying logical represenation is still
  7896 bogus);
  7897 
  7898 
  7899 *** ZF ***
  7900 
  7901 * ZF: simplification automatically cancels common terms in arithmetic
  7902 expressions over nat and int;
  7903 
  7904 * ZF: new treatment of nat to minimize type-checking: all operators
  7905 coerce their operands to a natural number using the function natify,
  7906 making the algebraic laws unconditional;
  7907 
  7908 * ZF: as above, for int: operators coerce their operands to an integer
  7909 using the function intify;
  7910 
  7911 * ZF: the integer library now contains many of the usual laws for the
  7912 orderings, including $<=, and monotonicity laws for $+ and $*;
  7913 
  7914 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7915 simplification;
  7916 
  7917 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7918 to the simplifier and classical reasoner simultaneously;
  7919 
  7920 
  7921 *** General ***
  7922 
  7923 * Provers: blast_tac now handles actual object-logic rules as
  7924 assumptions; note that auto_tac uses blast_tac internally as well;
  7925 
  7926 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7927 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7928 
  7929 * Provers: delrules now handles destruct rules as well (no longer need
  7930 explicit make_elim);
  7931 
  7932 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7933   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7934 use instead the strong form,
  7935   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7936 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7937 from destruct-rules;
  7938 
  7939 * Provers: Simplifier.easy_setup provides a fast path to basic
  7940 Simplifier setup for new object-logics;
  7941 
  7942 * Pure: AST translation rules no longer require constant head on LHS;
  7943 
  7944 * Pure: improved name spaces: ambiguous output is qualified; support
  7945 for hiding of names;
  7946 
  7947 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7948 XSYMBOL_HOME; no longer need to do manual configuration in most
  7949 situations;
  7950 
  7951 * system: compression of ML heaps images may now be controlled via -c
  7952 option of isabelle and isatool usedir (currently only observed by
  7953 Poly/ML);
  7954 
  7955 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7956 useful for remote X11);
  7957 
  7958 * system: provide TAGS file for Isabelle sources;
  7959 
  7960 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7961 order;
  7962 
  7963 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7964 timing flag supersedes proof_timing and Toplevel.trace;
  7965 
  7966 * ML: new combinators |>> and |>>> for incremental transformations
  7967 with secondary results (e.g. certain theory extensions):
  7968 
  7969 * ML: PureThy.add_defs gets additional argument to indicate potential
  7970 overloading (usually false);
  7971 
  7972 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7973 results;
  7974 
  7975 
  7976 
  7977 New in Isabelle99 (October 1999)
  7978 --------------------------------
  7979 
  7980 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7981 
  7982 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7983 are no longer simplified.  (This allows the simplifier to unfold recursive
  7984 functional programs.)  To restore the old behaviour, declare
  7985 
  7986     Delcongs [if_weak_cong];
  7987 
  7988 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7989 complement;
  7990 
  7991 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7992 
  7993 * HOL/datatype: mutual_induct_tac no longer exists --
  7994   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7995 
  7996 * HOL/typedef: fixed type inference for representing set; type
  7997 arguments now have to occur explicitly on the rhs as type constraints;
  7998 
  7999 * ZF: The con_defs part of an inductive definition may no longer refer
  8000 to constants declared in the same theory;
  8001 
  8002 * HOL, ZF: the function mk_cases, generated by the inductive
  8003 definition package, has lost an argument.  To simplify its result, it
  8004 uses the default simpset instead of a supplied list of theorems.
  8005 
  8006 * HOL/List: the constructors of type list are now Nil and Cons;
  8007 
  8008 * Simplifier: the type of the infix ML functions
  8009         setSSolver addSSolver setSolver addSolver
  8010 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  8011 for packaging solvers. A solver is created via
  8012         mk_solver: string -> (thm list -> int -> tactic) -> solver
  8013 where the string argument is only a comment.
  8014 
  8015 
  8016 *** Proof tools ***
  8017 
  8018 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  8019 decision procedure for linear arithmetic. Currently it is used for
  8020 types `nat', `int', and `real' in HOL (see below); it can, should and
  8021 will be instantiated for other types and logics as well.
  8022 
  8023 * The simplifier now accepts rewrite rules with flexible heads, eg
  8024      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  8025   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  8026   matching.
  8027 
  8028 
  8029 *** General ***
  8030 
  8031 * New Isabelle/Isar subsystem provides an alternative to traditional
  8032 tactical theorem proving; together with the ProofGeneral/isar user
  8033 interface it offers an interactive environment for developing human
  8034 readable proof documents (Isar == Intelligible semi-automated
  8035 reasoning); for further information see isatool doc isar-ref,
  8036 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  8037 
  8038 * improved and simplified presentation of theories: better HTML markup
  8039 (including colors), graph views in several sizes; isatool usedir now
  8040 provides a proper interface for user theories (via -P option); actual
  8041 document preparation based on (PDF)LaTeX is available as well (for
  8042 new-style theories only); see isatool doc system for more information;
  8043 
  8044 * native support for Proof General, both for classic Isabelle and
  8045 Isabelle/Isar;
  8046 
  8047 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  8048 using the graph browser tool;
  8049 
  8050 * Isabelle manuals now also available as PDF;
  8051 
  8052 * theory loader rewritten from scratch (may not be fully
  8053 bug-compatible); old loadpath variable has been replaced by show_path,
  8054 add_path, del_path, reset_path functions; new operations such as
  8055 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  8056 isatool doc ref);
  8057 
  8058 * improved isatool install: option -k creates KDE application icon,
  8059 option -p DIR installs standalone binaries;
  8060 
  8061 * added ML_PLATFORM setting (useful for cross-platform installations);
  8062 more robust handling of platform specific ML images for SML/NJ;
  8063 
  8064 * the settings environment is now statically scoped, i.e. it is never
  8065 created again in sub-processes invoked from isabelle, isatool, or
  8066 Isabelle;
  8067 
  8068 * path element specification '~~' refers to '$ISABELLE_HOME';
  8069 
  8070 * in locales, the "assumes" and "defines" parts may be omitted if
  8071 empty;
  8072 
  8073 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  8074 long arrows);
  8075 
  8076 * new print_mode "HTML";
  8077 
  8078 * new flag show_tags controls display of tags of theorems (which are
  8079 basically just comments that may be attached by some tools);
  8080 
  8081 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  8082 mode and goal output format:
  8083 
  8084 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  8085 244c244
  8086 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  8087 ---
  8088 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  8089 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  8090 181c181
  8091 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  8092 ---
  8093 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  8094 
  8095 * function bind_thms stores lists of theorems (cf. bind_thm);
  8096 
  8097 * new shorthand tactics ftac, eatac, datac, fatac;
  8098 
  8099 * qed (and friends) now accept "" as result name; in that case the
  8100 theorem is not stored, but proper checks and presentation of the
  8101 result still apply;
  8102 
  8103 * theorem database now also indexes constants "Trueprop", "all",
  8104 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  8105 
  8106 
  8107 *** HOL ***
  8108 
  8109 ** HOL arithmetic **
  8110 
  8111 * There are now decision procedures for linear arithmetic over nat and
  8112 int:
  8113 
  8114 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  8115 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  8116 are treated as atomic; subformulae not involving type `nat' or `int'
  8117 are ignored; quantified subformulae are ignored unless they are
  8118 positive universal or negative existential. The tactic has to be
  8119 invoked by hand and can be a little bit slow. In particular, the
  8120 running time is exponential in the number of occurrences of `min' and
  8121 `max', and `-' on `nat'.
  8122 
  8123 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  8124 (negated) (in)equalities among the premises and the conclusion into
  8125 account (i.e. no compound formulae) and does not know about `min' and
  8126 `max', and `-' on `nat'. It is fast and is used automatically by the
  8127 simplifier.
  8128 
  8129 NB: At the moment, these decision procedures do not cope with mixed
  8130 nat/int formulae where the two parts interact, such as `m < n ==>
  8131 int(m) < int(n)'.
  8132 
  8133 * HOL/Numeral provides a generic theory of numerals (encoded
  8134 efficiently as bit strings); setup for types nat/int/real is in place;
  8135 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  8136 int, existing theories and proof scripts may require a few additional
  8137 type constraints;
  8138 
  8139 * integer division and remainder can now be performed on constant
  8140 arguments;
  8141 
  8142 * many properties of integer multiplication, division and remainder
  8143 are now available;
  8144 
  8145 * An interface to the Stanford Validity Checker (SVC) is available through the
  8146 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  8147 are proved automatically.  SVC must be installed separately, and its results
  8148 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  8149 invocation of the underlying oracle).  For SVC see
  8150   http://verify.stanford.edu/SVC
  8151 
  8152 * IsaMakefile: the HOL-Real target now builds an actual image;
  8153 
  8154 
  8155 ** HOL misc **
  8156 
  8157 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  8158 (in Isabelle/Isar) -- by Gertrud Bauer;
  8159 
  8160 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  8161 analysis for assembly languages with subtypes;
  8162 
  8163 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  8164 -- avoids syntactic ambiguities and treats state, transition, and
  8165 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  8166 changed syntax and (many) tactics;
  8167 
  8168 * HOL/inductive: Now also handles more general introduction rules such
  8169   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  8170   theorems are now maintained within the theory (maintained via the
  8171   "mono" attribute);
  8172 
  8173 * HOL/datatype: Now also handles arbitrarily branching datatypes
  8174   (using function types) such as
  8175 
  8176   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  8177 
  8178 * HOL/record: record_simproc (part of the default simpset) takes care
  8179 of selectors applied to updated records; record_split_tac is no longer
  8180 part of the default claset; update_defs may now be removed from the
  8181 simpset in many cases; COMPATIBILITY: old behavior achieved by
  8182 
  8183   claset_ref () := claset() addSWrapper record_split_wrapper;
  8184   Delsimprocs [record_simproc]
  8185 
  8186 * HOL/typedef: fixed type inference for representing set; type
  8187 arguments now have to occur explicitly on the rhs as type constraints;
  8188 
  8189 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  8190 names rather than an ML expression;
  8191 
  8192 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  8193 supplied later.  Program schemes can be defined, such as
  8194     "While B C s = (if B s then While B C (C s) else s)"
  8195 where the well-founded relation can be chosen after B and C have been given.
  8196 
  8197 * HOL/List: the constructors of type list are now Nil and Cons;
  8198 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  8199 course, ML tools referring to List.list.op # etc. have to be adapted;
  8200 
  8201 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  8202 disabled by default; run isabelle with option -m HOL to get back to
  8203 the original Gordon/HOL-style output;
  8204 
  8205 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  8206 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  8207 
  8208 * HOL basic syntax simplified (more orthogonal): all variants of
  8209 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  8210 Eps operator is provided as well: "SOME x. P[x]";
  8211 
  8212 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  8213 
  8214 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  8215 thus available for user theories;
  8216 
  8217 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  8218 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  8219 time;
  8220 
  8221 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  8222 several times and then mp;
  8223 
  8224 
  8225 *** LK ***
  8226 
  8227 * the notation <<...>> is now available as a notation for sequences of
  8228 formulas;
  8229 
  8230 * the simplifier is now installed
  8231 
  8232 * the axiom system has been generalized (thanks to Soren Heilmann)
  8233 
  8234 * the classical reasoner now has a default rule database
  8235 
  8236 
  8237 *** ZF ***
  8238 
  8239 * new primrec section allows primitive recursive functions to be given
  8240 directly (as in HOL) over datatypes and the natural numbers;
  8241 
  8242 * new tactics induct_tac and exhaust_tac for induction (or case
  8243 analysis) over datatypes and the natural numbers;
  8244 
  8245 * the datatype declaration of type T now defines the recursor T_rec;
  8246 
  8247 * simplification automatically does freeness reasoning for datatype
  8248 constructors;
  8249 
  8250 * automatic type-inference, with AddTCs command to insert new
  8251 type-checking rules;
  8252 
  8253 * datatype introduction rules are now added as Safe Introduction rules
  8254 to the claset;
  8255 
  8256 * the syntax "if P then x else y" is now available in addition to
  8257 if(P,x,y);
  8258 
  8259 
  8260 *** Internal programming interfaces ***
  8261 
  8262 * tuned simplifier trace output; new flag debug_simp;
  8263 
  8264 * structures Vartab / Termtab (instances of TableFun) offer efficient
  8265 tables indexed by indexname_ord / term_ord (compatible with aconv);
  8266 
  8267 * AxClass.axclass_tac lost the theory argument;
  8268 
  8269 * tuned current_goals_markers semantics: begin / end goal avoids
  8270 printing empty lines;
  8271 
  8272 * removed prs and prs_fn hook, which was broken because it did not
  8273 include \n in its semantics, forcing writeln to add one
  8274 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  8275 string -> unit if you really want to output text without newline;
  8276 
  8277 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  8278 plain output, interface builders may have to enable 'isabelle_font'
  8279 mode to get Isabelle font glyphs as before;
  8280 
  8281 * refined token_translation interface; INCOMPATIBILITY: output length
  8282 now of type real instead of int;
  8283 
  8284 * theory loader actions may be traced via new ThyInfo.add_hook
  8285 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8286 your own database of information attached to *whole* theories -- as
  8287 opposed to intra-theory data slots offered via TheoryDataFun;
  8288 
  8289 * proper handling of dangling sort hypotheses (at last!);
  8290 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8291 extra sort hypotheses that can be witnessed from the type signature;
  8292 the force_strip_shyps flag is gone, any remaining shyps are simply
  8293 left in the theorem (with a warning issued by strip_shyps_warning);
  8294 
  8295 
  8296 
  8297 New in Isabelle98-1 (October 1998)
  8298 ----------------------------------
  8299 
  8300 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8301 
  8302 * several changes of automated proof tools;
  8303 
  8304 * HOL: major changes to the inductive and datatype packages, including
  8305 some minor incompatibilities of theory syntax;
  8306 
  8307 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8308 called `inj_on';
  8309 
  8310 * HOL: removed duplicate thms in Arith:
  8311   less_imp_add_less  should be replaced by  trans_less_add1
  8312   le_imp_add_le      should be replaced by  trans_le_add1
  8313 
  8314 * HOL: unary minus is now overloaded (new type constraints may be
  8315 required);
  8316 
  8317 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8318 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8319 now taken as an integer constant.
  8320 
  8321 * Pure: ML function 'theory_of' renamed to 'theory';
  8322 
  8323 
  8324 *** Proof tools ***
  8325 
  8326 * Simplifier:
  8327   1. Asm_full_simp_tac is now more aggressive.
  8328      1. It will sometimes reorient premises if that increases their power to
  8329         simplify.
  8330      2. It does no longer proceed strictly from left to right but may also
  8331         rotate premises to achieve further simplification.
  8332      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8333      old Asm_full_simp_tac in that it does not rotate premises.
  8334   2. The simplifier now knows a little bit about nat-arithmetic.
  8335 
  8336 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8337 allows for selected deletion of wrappers, by introduction of names for
  8338 wrapper functionals.  This implies that addbefore, addSbefore,
  8339 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8340 and that adding two tactics with the same name overwrites the first
  8341 one (emitting a warning).
  8342   type wrapper = (int -> tactic) -> (int -> tactic)
  8343   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8344   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8345   delWrapper, delSWrapper: claset *  string            -> claset
  8346   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8347 
  8348 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8349 semantics; addbefore now affects only the unsafe part of step_tac
  8350 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8351 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8352 by Force_tac;
  8353 
  8354 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8355 compWrapper; added safe wrapper (and access functions for it);
  8356 
  8357 * HOL/split_all_tac is now much faster and fails if there is nothing
  8358 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8359 and the names of the automatically generated variables have changed.
  8360 split_all_tac has moved within claset() from unsafe wrappers to safe
  8361 wrappers, which means that !!-bound variables are split much more
  8362 aggressively, and safe_tac and clarify_tac now split such variables.
  8363 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8364 Note: the same holds for record_split_tac, which does the job of
  8365 split_all_tac for record fields.
  8366 
  8367 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8368 permanently to the default simpset using Addsplits just like
  8369 Addsimps. They can be removed via Delsplits just like
  8370 Delsimps. Lower-case versions are also available.
  8371 
  8372 * HOL/Simplifier: The rule split_if is now part of the default
  8373 simpset. This means that the simplifier will eliminate all occurrences
  8374 of if-then-else in the conclusion of a goal. To prevent this, you can
  8375 either remove split_if completely from the default simpset by
  8376 `Delsplits [split_if]' or remove it in a specific call of the
  8377 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8378 other case splitting rules to/from the default simpset: every datatype
  8379 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8380 t is the name of the datatype).
  8381 
  8382 * Classical reasoner / Simplifier combination: new force_tac (and
  8383 derivatives Force_tac, force) combines rewriting and classical
  8384 reasoning (and whatever other tools) similarly to auto_tac, but is
  8385 aimed to solve the given subgoal completely.
  8386 
  8387 
  8388 *** General ***
  8389 
  8390 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8391 and `goalw': the theory is no longer needed as an explicit argument -
  8392 the current theory context is used; assumptions are no longer returned
  8393 at the ML-level unless one of them starts with ==> or !!; it is
  8394 recommended to convert to these new commands using isatool fixgoal
  8395 (backup your sources first!);
  8396 
  8397 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8398 the current theory context, and 'theory' to lookup stored theories;
  8399 
  8400 * new theory section 'locale' for declaring constants, assumptions and
  8401 definitions that have local scope;
  8402 
  8403 * new theory section 'nonterminals' for purely syntactic types;
  8404 
  8405 * new theory section 'setup' for generic ML setup functions
  8406 (e.g. package initialization);
  8407 
  8408 * the distribution now includes Isabelle icons: see
  8409 lib/logo/isabelle-{small,tiny}.xpm;
  8410 
  8411 * isatool install - install binaries with absolute references to
  8412 ISABELLE_HOME/bin;
  8413 
  8414 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8415 
  8416 * print mode 'emacs' reserved for Isamode;
  8417 
  8418 * support multiple print (ast) translations per constant name;
  8419 
  8420 * theorems involving oracles are now printed with a suffixed [!];
  8421 
  8422 
  8423 *** HOL ***
  8424 
  8425 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8426 
  8427 * HOL/inductive package reorganized and improved: now supports mutual
  8428 definitions such as
  8429 
  8430   inductive EVEN ODD
  8431     intrs
  8432       null "0 : EVEN"
  8433       oddI "n : EVEN ==> Suc n : ODD"
  8434       evenI "n : ODD ==> Suc n : EVEN"
  8435 
  8436 new theorem list "elims" contains an elimination rule for each of the
  8437 recursive sets; inductive definitions now handle disjunctive premises
  8438 correctly (also ZF);
  8439 
  8440 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  8441 "mutual_induct" no longer exists - the induction rule is always
  8442 contained in "induct";
  8443 
  8444 
  8445 * HOL/datatype package re-implemented and greatly improved: now
  8446 supports mutually recursive datatypes such as
  8447 
  8448   datatype
  8449     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  8450             | SUM ('a aexp) ('a aexp)
  8451             | DIFF ('a aexp) ('a aexp)
  8452             | NUM 'a
  8453   and
  8454     'a bexp = LESS ('a aexp) ('a aexp)
  8455             | AND ('a bexp) ('a bexp)
  8456             | OR ('a bexp) ('a bexp)
  8457 
  8458 as well as indirectly recursive datatypes such as
  8459 
  8460   datatype
  8461     ('a, 'b) term = Var 'a
  8462                   | App 'b ((('a, 'b) term) list)
  8463 
  8464 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  8465 induction on mutually / indirectly recursive datatypes.
  8466 
  8467 Primrec equations are now stored in theory and can be accessed via
  8468 <function_name>.simps.
  8469 
  8470 INCOMPATIBILITIES:
  8471 
  8472   - Theories using datatypes must now have theory Datatype as an
  8473     ancestor.
  8474   - The specific <typename>.induct_tac no longer exists - use the
  8475     generic induct_tac instead.
  8476   - natE has been renamed to nat.exhaust - use exhaust_tac
  8477     instead of res_inst_tac ... natE. Note that the variable
  8478     names in nat.exhaust differ from the names in natE, this
  8479     may cause some "fragile" proofs to fail.
  8480   - The theorems split_<typename>_case and split_<typename>_case_asm
  8481     have been renamed to <typename>.split and <typename>.split_asm.
  8482   - Since default sorts of type variables are now handled correctly,
  8483     some datatype definitions may have to be annotated with explicit
  8484     sort constraints.
  8485   - Primrec definitions no longer require function name and type
  8486     of recursive argument.
  8487 
  8488 Consider using isatool fixdatatype to adapt your theories and proof
  8489 scripts to the new package (backup your sources first!).
  8490 
  8491 
  8492 * HOL/record package: considerably improved implementation; now
  8493 includes concrete syntax for record types, terms, updates; theorems
  8494 for surjective pairing and splitting !!-bound record variables; proof
  8495 support is as follows:
  8496 
  8497   1) standard conversions (selectors or updates applied to record
  8498 constructor terms) are part of the standard simpset;
  8499 
  8500   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  8501 made part of standard simpset and claset via addIffs;
  8502 
  8503   3) a tactic for record field splitting (record_split_tac) is part of
  8504 the standard claset (addSWrapper);
  8505 
  8506 To get a better idea about these rules you may retrieve them via
  8507 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  8508 the name of your record type.
  8509 
  8510 The split tactic 3) conceptually simplifies by the following rule:
  8511 
  8512   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  8513 
  8514 Thus any record variable that is bound by meta-all will automatically
  8515 blow up into some record constructor term, consequently the
  8516 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  8517 solve record problems automatically.
  8518 
  8519 
  8520 * reorganized the main HOL image: HOL/Integ and String loaded by
  8521 default; theory Main includes everything;
  8522 
  8523 * automatic simplification of integer sums and comparisons, using cancellation;
  8524 
  8525 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  8526 
  8527 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  8528 
  8529 * many new identities for unions, intersections, set difference, etc.;
  8530 
  8531 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  8532 called split_if, split_split, split_sum_case and split_nat_case (to go
  8533 with add/delsplits);
  8534 
  8535 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  8536 (?x::unit) = (); this is made part of the default simpset, which COULD
  8537 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  8538 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  8539 unit_abs_eta_conv is added in order to counter the effect of
  8540 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  8541 %u.f();
  8542 
  8543 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  8544 makes more sense);
  8545 
  8546 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8547   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8548   disjointness reasoning but breaking a few old proofs.
  8549 
  8550 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  8551 to 'converse' from 'inverse' (for compatibility with ZF and some
  8552 literature);
  8553 
  8554 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  8555 the well-founded relation;
  8556 
  8557 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  8558     Compl A.  The "Compl" syntax remains available as input syntax for this
  8559     release ONLY.
  8560 
  8561 * HOL/Update: new theory of function updates:
  8562     f(a:=b) == %x. if x=a then b else f x
  8563 may also be iterated as in f(a:=b,c:=d,...);
  8564 
  8565 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  8566 
  8567 * HOL/List:
  8568   - new function list_update written xs[i:=v] that updates the i-th
  8569     list position. May also be iterated as in xs[i:=a,j:=b,...].
  8570   - new function `upt' written [i..j(] which generates the list
  8571     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  8572     bound write [i..j], which is a shorthand for [i..j+1(].
  8573   - new lexicographic orderings and corresponding wellfoundedness theorems.
  8574 
  8575 * HOL/Arith:
  8576   - removed 'pred' (predecessor) function;
  8577   - generalized some theorems about n-1;
  8578   - many new laws about "div" and "mod";
  8579   - new laws about greatest common divisors (see theory ex/Primes);
  8580 
  8581 * HOL/Relation: renamed the relational operator r^-1 "converse"
  8582 instead of "inverse";
  8583 
  8584 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  8585   of the multiset ordering;
  8586 
  8587 * directory HOL/Real: a construction of the reals using Dedekind cuts
  8588   (not included by default);
  8589 
  8590 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  8591 
  8592 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  8593   programs, i.e. different program variables may have different types.
  8594 
  8595 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8596   [previously, this check worked only if the rewrite rule was unconditional]
  8597   Now rew can involve either definitions or equalities (either == or =).
  8598 
  8599 
  8600 *** ZF ***
  8601 
  8602 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  8603   only the theorems proved on ZF.ML;
  8604 
  8605 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8606   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8607   disjointness reasoning but breaking a few old proofs.
  8608 
  8609 * ZF/Update: new theory of function updates
  8610     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  8611   may also be iterated as in f(a:=b,c:=d,...);
  8612 
  8613 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  8614 
  8615 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8616   [previously, this check worked only if the rewrite rule was unconditional]
  8617   Now rew can involve either definitions or equalities (either == or =).
  8618 
  8619 * case_tac provided for compatibility with HOL
  8620     (like the old excluded_middle_tac, but with subgoals swapped)
  8621 
  8622 
  8623 *** Internal programming interfaces ***
  8624 
  8625 * Pure: several new basic modules made available for general use, see
  8626 also src/Pure/README;
  8627 
  8628 * improved the theory data mechanism to support encapsulation (data
  8629 kind name replaced by private Object.kind, acting as authorization
  8630 key); new type-safe user interface via functor TheoryDataFun; generic
  8631 print_data function becomes basically useless;
  8632 
  8633 * removed global_names compatibility flag -- all theory declarations
  8634 are qualified by default;
  8635 
  8636 * module Pure/Syntax now offers quote / antiquote translation
  8637 functions (useful for Hoare logic etc. with implicit dependencies);
  8638 see HOL/ex/Antiquote for an example use;
  8639 
  8640 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  8641 cterm -> thm;
  8642 
  8643 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  8644 subgoal;
  8645 
  8646 * Display.print_goals function moved to Locale.print_goals;
  8647 
  8648 * standard print function for goals supports current_goals_markers
  8649 variable for marking begin of proof, end of proof, start of goal; the
  8650 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  8651 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  8652 for example;
  8653 
  8654 
  8655 
  8656 New in Isabelle98 (January 1998)
  8657 --------------------------------
  8658 
  8659 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8660 
  8661 * changed lexical syntax of terms / types: dots made part of long
  8662 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  8663 
  8664 * simpset (and claset) reference variable replaced by functions
  8665 simpset / simpset_ref;
  8666 
  8667 * no longer supports theory aliases (via merge) and non-trivial
  8668 implicit merge of thms' signatures;
  8669 
  8670 * most internal names of constants changed due to qualified names;
  8671 
  8672 * changed Pure/Sequence interface (see Pure/seq.ML);
  8673 
  8674 
  8675 *** General Changes ***
  8676 
  8677 * hierachically structured name spaces (for consts, types, axms, thms
  8678 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  8679 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  8680 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  8681 long_names for fully qualified output names; NOTE: ML programs
  8682 (special tactics, packages etc.) referring to internal names may have
  8683 to be adapted to cope with fully qualified names; in case of severe
  8684 backward campatibility problems try setting 'global_names' at compile
  8685 time to have enrything declared within a flat name space; one may also
  8686 fine tune name declarations in theories via the 'global' and 'local'
  8687 section;
  8688 
  8689 * reimplemented the implicit simpset and claset using the new anytype
  8690 data filed in signatures; references simpset:simpset ref etc. are
  8691 replaced by functions simpset:unit->simpset and
  8692 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  8693 to patch your ML files accordingly;
  8694 
  8695 * HTML output now includes theory graph data for display with Java
  8696 applet or isatool browser; data generated automatically via isatool
  8697 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  8698 
  8699 * defs may now be conditional; improved rewrite_goals_tac to handle
  8700 conditional equations;
  8701 
  8702 * defs now admits additional type arguments, using TYPE('a) syntax;
  8703 
  8704 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  8705 creates a new theory node; implicit merge of thms' signatures is
  8706 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  8707 transfer:theory->thm->thm in (rare) cases;
  8708 
  8709 * improved handling of draft signatures / theories; draft thms (and
  8710 ctyps, cterms) are automatically promoted to real ones;
  8711 
  8712 * slightly changed interfaces for oracles: admit many per theory, named
  8713 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  8714 
  8715 * print_goals: optional output of const types (set show_consts and
  8716 show_types);
  8717 
  8718 * improved output of warnings (###) and errors (***);
  8719 
  8720 * subgoal_tac displays a warning if the new subgoal has type variables;
  8721 
  8722 * removed old README and Makefiles;
  8723 
  8724 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  8725 
  8726 * removed obsolete init_pps and init_database;
  8727 
  8728 * deleted the obsolete tactical STATE, which was declared by
  8729     fun STATE tacfun st = tacfun st st;
  8730 
  8731 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  8732 (which abbreviates $HOME);
  8733 
  8734 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  8735 use isatool fixseq to adapt your ML programs (this works for fully
  8736 qualified references to the Sequence structure only!);
  8737 
  8738 * use_thy no longer requires writable current directory; it always
  8739 reloads .ML *and* .thy file, if either one is out of date;
  8740 
  8741 
  8742 *** Classical Reasoner ***
  8743 
  8744 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  8745 tactics that use classical reasoning to simplify a subgoal without
  8746 splitting it into several subgoals;
  8747 
  8748 * Safe_tac: like safe_tac but uses the default claset;
  8749 
  8750 
  8751 *** Simplifier ***
  8752 
  8753 * added simplification meta rules:
  8754     (asm_)(full_)simplify: simpset -> thm -> thm;
  8755 
  8756 * simplifier.ML no longer part of Pure -- has to be loaded by object
  8757 logics (again);
  8758 
  8759 * added prems argument to simplification procedures;
  8760 
  8761 * HOL, FOL, ZF: added infix function `addsplits':
  8762   instead of `<simpset> setloop (split_tac <thms>)'
  8763   you can simply write `<simpset> addsplits <thms>'
  8764 
  8765 
  8766 *** Syntax ***
  8767 
  8768 * TYPE('a) syntax for type reflection terms;
  8769 
  8770 * no longer handles consts with name "" -- declare as 'syntax' instead;
  8771 
  8772 * pretty printer: changed order of mixfix annotation preference (again!);
  8773 
  8774 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  8775 
  8776 
  8777 *** HOL ***
  8778 
  8779 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8780   with `addloop' of the simplifier to faciliate case splitting in premises.
  8781 
  8782 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  8783 
  8784 * HOL/Auth: new protocol proofs including some for the Internet
  8785   protocol TLS;
  8786 
  8787 * HOL/Map: new theory of `maps' a la VDM;
  8788 
  8789 * HOL/simplifier: simplification procedures nat_cancel_sums for
  8790 cancelling out common nat summands from =, <, <= (in)equalities, or
  8791 differences; simplification procedures nat_cancel_factor for
  8792 cancelling common factor from =, <, <= (in)equalities over natural
  8793 sums; nat_cancel contains both kinds of procedures, it is installed by
  8794 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  8795 
  8796 * HOL/simplifier: terms of the form
  8797   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  8798   are rewritten to
  8799   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  8800   and those of the form
  8801   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  8802   are rewritten to
  8803   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  8804 
  8805 * HOL/datatype
  8806   Each datatype `t' now comes with a theorem `split_t_case' of the form
  8807 
  8808   P(t_case f1 ... fn x) =
  8809      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  8810         ...
  8811        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  8812      )
  8813 
  8814   and a theorem `split_t_case_asm' of the form
  8815 
  8816   P(t_case f1 ... fn x) =
  8817     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  8818         ...
  8819        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  8820      )
  8821   which can be added to a simpset via `addsplits'. The existing theorems
  8822   expand_list_case and expand_option_case have been renamed to
  8823   split_list_case and split_option_case.
  8824 
  8825 * HOL/Arithmetic:
  8826   - `pred n' is automatically converted to `n-1'.
  8827     Users are strongly encouraged not to use `pred' any longer,
  8828     because it will disappear altogether at some point.
  8829   - Users are strongly encouraged to write "0 < n" rather than
  8830     "n ~= 0". Theorems and proof tools have been modified towards this
  8831     `standard'.
  8832 
  8833 * HOL/Lists:
  8834   the function "set_of_list" has been renamed "set" (and its theorems too);
  8835   the function "nth" now takes its arguments in the reverse order and
  8836   has acquired the infix notation "!" as in "xs!n".
  8837 
  8838 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  8839 
  8840 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  8841   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  8842 
  8843 * HOL/record: extensible records with schematic structural subtyping
  8844 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  8845 still lacks various theorems and concrete record syntax;
  8846 
  8847 
  8848 *** HOLCF ***
  8849 
  8850 * removed "axioms" and "generated by" sections;
  8851 
  8852 * replaced "ops" section by extended "consts" section, which is capable of
  8853   handling the continuous function space "->" directly;
  8854 
  8855 * domain package:
  8856   . proves theorems immediately and stores them in the theory,
  8857   . creates hierachical name space,
  8858   . now uses normal mixfix annotations (instead of cinfix...),
  8859   . minor changes to some names and values (for consistency),
  8860   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  8861   . separator between mutual domain defs: changed "," to "and",
  8862   . improved handling of sort constraints;  now they have to
  8863     appear on the left-hand side of the equations only;
  8864 
  8865 * fixed LAM <x,y,zs>.b syntax;
  8866 
  8867 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  8868 adm (%x. P (t x)), where P is chainfinite and t continuous;
  8869 
  8870 
  8871 *** FOL and ZF ***
  8872 
  8873 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8874   with `addloop' of the simplifier to faciliate case splitting in premises.
  8875 
  8876 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8877 in HOL, they strip ALL and --> from proved theorems;
  8878 
  8879 
  8880 
  8881 New in Isabelle94-8 (May 1997)
  8882 ------------------------------
  8883 
  8884 *** General Changes ***
  8885 
  8886 * new utilities to build / run / maintain Isabelle etc. (in parts
  8887 still somewhat experimental); old Makefiles etc. still functional;
  8888 
  8889 * new 'Isabelle System Manual';
  8890 
  8891 * INSTALL text, together with ./configure and ./build scripts;
  8892 
  8893 * reimplemented type inference for greater efficiency, better error
  8894 messages and clean internal interface;
  8895 
  8896 * prlim command for dealing with lots of subgoals (an easier way of
  8897 setting goals_limit);
  8898 
  8899 
  8900 *** Syntax ***
  8901 
  8902 * supports alternative (named) syntax tables (parser and pretty
  8903 printer); internal interface is provided by add_modesyntax(_i);
  8904 
  8905 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8906 be used in conjunction with the Isabelle symbol font; uses the
  8907 "symbols" syntax table;
  8908 
  8909 * added token_translation interface (may translate name tokens in
  8910 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8911 the current print_mode); IMPORTANT: user print translation functions
  8912 are responsible for marking newly introduced bounds
  8913 (Syntax.mark_boundT);
  8914 
  8915 * token translations for modes "xterm" and "xterm_color" that display
  8916 names in bold, underline etc. or colors (which requires a color
  8917 version of xterm);
  8918 
  8919 * infixes may now be declared with names independent of their syntax;
  8920 
  8921 * added typed_print_translation (like print_translation, but may
  8922 access type of constant);
  8923 
  8924 
  8925 *** Classical Reasoner ***
  8926 
  8927 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8928 some limitations.  Blast_tac...
  8929   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8930   + ignores elimination rules that don't have the correct format
  8931         (the conclusion MUST be a formula variable)
  8932   + ignores types, which can make HOL proofs fail
  8933   + rules must not require higher-order unification, e.g. apply_type in ZF
  8934     [message "Function Var's argument not a bound variable" relates to this]
  8935   + its proof strategy is more general but can actually be slower
  8936 
  8937 * substitution with equality assumptions no longer permutes other
  8938 assumptions;
  8939 
  8940 * minor changes in semantics of addafter (now called addaltern); renamed
  8941 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8942 (and access functions for it);
  8943 
  8944 * improved combination of classical reasoner and simplifier:
  8945   + functions for handling clasimpsets
  8946   + improvement of addss: now the simplifier is called _after_ the
  8947     safe steps.
  8948   + safe variant of addss called addSss: uses safe simplifications
  8949     _during_ the safe steps. It is more complete as it allows multiple
  8950     instantiations of unknowns (e.g. with slow_tac).
  8951 
  8952 *** Simplifier ***
  8953 
  8954 * added interface for simplification procedures (functions that
  8955 produce *proven* rewrite rules on the fly, depending on current
  8956 redex);
  8957 
  8958 * ordering on terms as parameter (used for ordered rewriting);
  8959 
  8960 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8961 
  8962 * the solver is now split into a safe and an unsafe part.
  8963 This should be invisible for the normal user, except that the
  8964 functions setsolver and addsolver have been renamed to setSolver and
  8965 addSolver; added safe_asm_full_simp_tac;
  8966 
  8967 
  8968 *** HOL ***
  8969 
  8970 * a generic induction tactic `induct_tac' which works for all datatypes and
  8971 also for type `nat';
  8972 
  8973 * a generic case distinction tactic `exhaust_tac' which works for all
  8974 datatypes and also for type `nat';
  8975 
  8976 * each datatype comes with a function `size';
  8977 
  8978 * patterns in case expressions allow tuple patterns as arguments to
  8979 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8980 
  8981 * primrec now also works with type nat;
  8982 
  8983 * recdef: a new declaration form, allows general recursive functions to be
  8984 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8985 
  8986 * the constant for negation has been renamed from "not" to "Not" to
  8987 harmonize with FOL, ZF, LK, etc.;
  8988 
  8989 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8990 infinite lists;
  8991 
  8992 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8993 
  8994 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8995 problems in commutative rings, using axiomatic type classes for + and *;
  8996 
  8997 * more examples in HOL/MiniML and HOL/Auth;
  8998 
  8999 * more default rewrite rules for quantifiers, union/intersection;
  9000 
  9001 * a new constant `arbitrary == @x.False';
  9002 
  9003 * HOLCF/IOA replaces old HOL/IOA;
  9004 
  9005 * HOLCF changes: derived all rules and arities
  9006   + axiomatic type classes instead of classes
  9007   + typedef instead of faking type definitions
  9008   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  9009   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  9010   + eliminated the types void, one, tr
  9011   + use unit lift and bool lift (with translations) instead of one and tr
  9012   + eliminated blift from Lift3.thy (use Def instead of blift)
  9013   all eliminated rules are derived as theorems --> no visible changes ;
  9014 
  9015 
  9016 *** ZF ***
  9017 
  9018 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  9019 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  9020 as ZF_cs addSIs [equalityI];
  9021 
  9022 
  9023 
  9024 New in Isabelle94-7 (November 96)
  9025 ---------------------------------
  9026 
  9027 * allowing negative levels (as offsets) in prlev and choplev;
  9028 
  9029 * super-linear speedup for large simplifications;
  9030 
  9031 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  9032 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  9033 FAIL); can suppress it using the command Delsimps (ex_simps @
  9034 all_simps); De Morgan laws are also now included, by default;
  9035 
  9036 * improved printing of ==>  :  ~:
  9037 
  9038 * new object-logic "Sequents" adds linear logic, while replacing LK
  9039 and Modal (thanks to Sara Kalvala);
  9040 
  9041 * HOL/Auth: correctness proofs for authentication protocols;
  9042 
  9043 * HOL: new auto_tac combines rewriting and classical reasoning (many
  9044 examples on HOL/Auth);
  9045 
  9046 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  9047 the rewriter and classical reasoner simultaneously;
  9048 
  9049 * function uresult no longer returns theorems in "standard" format;
  9050 regain previous version by: val uresult = standard o uresult;
  9051 
  9052 
  9053 
  9054 New in Isabelle94-6
  9055 -------------------
  9056 
  9057 * oracles -- these establish an interface between Isabelle and trusted
  9058 external reasoners, which may deliver results as theorems;
  9059 
  9060 * proof objects (in particular record all uses of oracles);
  9061 
  9062 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  9063 
  9064 * "constdefs" section in theory files;
  9065 
  9066 * "primrec" section (HOL) no longer requires names;
  9067 
  9068 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  9069 
  9070 
  9071 
  9072 New in Isabelle94-5
  9073 -------------------
  9074 
  9075 * reduced space requirements;
  9076 
  9077 * automatic HTML generation from theories;
  9078 
  9079 * theory files no longer require "..." (quotes) around most types;
  9080 
  9081 * new examples, including two proofs of the Church-Rosser theorem;
  9082 
  9083 * non-curried (1994) version of HOL is no longer distributed;
  9084 
  9085 
  9086 
  9087 New in Isabelle94-4
  9088 -------------------
  9089 
  9090 * greatly reduced space requirements;
  9091 
  9092 * theory files (.thy) no longer require \...\ escapes at line breaks;
  9093 
  9094 * searchable theorem database (see the section "Retrieving theorems" on
  9095 page 8 of the Reference Manual);
  9096 
  9097 * new examples, including Grabczewski's monumental case study of the
  9098 Axiom of Choice;
  9099 
  9100 * The previous version of HOL renamed to Old_HOL;
  9101 
  9102 * The new version of HOL (previously called CHOL) uses a curried syntax
  9103 for functions.  Application looks like f a b instead of f(a,b);
  9104 
  9105 * Mutually recursive inductive definitions finally work in HOL;
  9106 
  9107 * In ZF, pattern-matching on tuples is now available in all abstractions and
  9108 translates to the operator "split";
  9109 
  9110 
  9111 
  9112 New in Isabelle94-3
  9113 -------------------
  9114 
  9115 * new infix operator, addss, allowing the classical reasoner to
  9116 perform simplification at each step of its search.  Example:
  9117         fast_tac (cs addss ss)
  9118 
  9119 * a new logic, CHOL, the same as HOL, but with a curried syntax
  9120 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  9121 look like (a,b) instead of <a,b>;
  9122 
  9123 * PLEASE NOTE: CHOL will eventually replace HOL!
  9124 
  9125 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  9126 It translates to the operator "split".  A new theory of integers is available;
  9127 
  9128 * In ZF, integer numerals now denote two's-complement binary integers.
  9129 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  9130 
  9131 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  9132 of the Axiom of Choice;
  9133 
  9134 
  9135 
  9136 New in Isabelle94-2
  9137 -------------------
  9138 
  9139 * Significantly faster resolution;
  9140 
  9141 * the different sections in a .thy file can now be mixed and repeated
  9142 freely;
  9143 
  9144 * Database of theorems for FOL, HOL and ZF.  New
  9145 commands including qed, qed_goal and bind_thm store theorems in the database.
  9146 
  9147 * Simple database queries: return a named theorem (get_thm) or all theorems of
  9148 a given theory (thms_of), or find out what theory a theorem was proved in
  9149 (theory_of_thm);
  9150 
  9151 * Bugs fixed in the inductive definition and datatype packages;
  9152 
  9153 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  9154 and HOL_dup_cs obsolete;
  9155 
  9156 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  9157 have been removed;
  9158 
  9159 * Simpler definition of function space in ZF;
  9160 
  9161 * new results about cardinal and ordinal arithmetic in ZF;
  9162 
  9163 * 'subtype' facility in HOL for introducing new types as subsets of existing
  9164 types;
  9165 
  9166 :mode=text:wrap=hard:maxLineLen=72: