NEWS
author huffman
Wed, 28 Mar 2012 08:25:51 +0200
changeset 48043 9fc17f9ccd6c
parent 48038 099397de21e3
parent 48029 d317a71f24d5
child 48056 300fa46fd081
permissions -rw-r--r--
merged
     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), derived from JAVA_HOME from the shell environment or
    52 java.home of the running JVM.
    53 
    54 
    55 *** Pure ***
    56 
    57 * Command 'definition' no longer exports the foundational "raw_def"
    58 into the user context.  Minor INCOMPATIBILITY, may use the regular
    59 "def" result with attribute "abs_def" to imitate the old version.
    60 
    61 * Attribute "abs_def" turns an equation of the form "f x y == t" into
    62 "f == %x y. t", which ensures that "simp" or "unfold" steps always
    63 expand it.  This also works for object-logic equality.  (Formerly
    64 undocumented feature.)
    65 
    66 * Discontinued old "prems" fact, which used to refer to the accidental
    67 collection of foundational premises in the context (marked as legacy
    68 since Isabelle2011).
    69 
    70 * Obsolete command 'types' has been discontinued.  Use 'type_synonym'
    71 instead.  INCOMPATIBILITY.
    72 
    73 * Ancient code generator for SML and its commands 'code_module',
    74 'code_library', 'consts_code', 'types_code' have been discontinued.
    75 Use commands of the generic code generator instead.  INCOMPATIBILITY.
    76 
    77 * Redundant attribute 'code_inline' has been discontinued. Use
    78 'code_unfold' instead.  INCOMPATIBILITY.
    79 
    80 * Dropped attribute 'code_unfold_post' in favor of the its dual
    81 'code_abbrev', which yields a common pattern in definitions like
    82 
    83   definition [code_abbrev]: "f = t"
    84 
    85 INCOMPATIBILITY.
    86 
    87 * Sort constraints are now propagated in simultaneous statements, just
    88 like type constraints.  INCOMPATIBILITY in rare situations, where
    89 distinct sorts used to be assigned accidentally.  For example:
    90 
    91   lemma "P (x::'a::foo)" and "Q (y::'a::bar)"  -- "now illegal"
    92 
    93   lemma "P (x::'a)" and "Q (y::'a::bar)"
    94     -- "now uniform 'a::bar instead of default sort for first occurence (!)"
    95 
    96 
    97 *** HOL ***
    98 
    99 * The representation of numerals has changed. We now have a datatype
   100 "num" representing strictly positive binary numerals, along with
   101 functions "numeral :: num => 'a" and "neg_numeral :: num => 'a" to
   102 represent positive and negated numeric literals, respectively. (See
   103 definitions in Num.thy.) Potential INCOMPATIBILITY; some user theories
   104 may require adaptations:
   105 
   106   - Theorems with number_ring or number_semiring constraints: These
   107     classes are gone; use comm_ring_1 or comm_semiring_1 instead.
   108 
   109   - Theories defining numeric types: Remove number, number_semiring,
   110     and number_ring instances. Defer all theorems about numerals until
   111     after classes one and semigroup_add have been instantiated.
   112 
   113   - Numeral-only simp rules: Replace each rule having a "number_of v"
   114     pattern with two copies, one for numeral and one for neg_numeral.
   115 
   116   - Theorems about subclasses of semiring_1 or ring_1: These classes
   117     automatically support numerals now, so more simp rules and
   118     simprocs may now apply within the proof.
   119 
   120   - Definitions and theorems using old constructors Pls/Min/Bit0/Bit1:
   121     Redefine using other integer operations.
   122 
   123 * Type 'a set is now a proper type constructor (just as before
   124 Isabelle2008).  Definitions mem_def and Collect_def have disappeared.
   125 Non-trivial INCOMPATIBILITY.  For developments keeping predicates and
   126 sets separate, it is often sufficient to rephrase sets S accidentally
   127 used as predicates by "%x. x : S" and predicates P accidentally used
   128 as sets by "{x. P x}".  Corresponding proofs in a first step should be
   129 pruned from any tinkering with former theorems mem_def and
   130 Collect_def as far as possible.
   131 For developments which deliberately mixed predicates and
   132 sets, a planning step is necessary to determine what should become a
   133 predicate and what a set.  It can be helpful to carry out that step in
   134 Isabelle2011-1 before jumping right into the current release.
   135 
   136 * Code generation by default implements sets as container type rather
   137 than predicates.  INCOMPATIBILITY.
   138 
   139 * New type synonym 'a rel = ('a * 'a) set
   140 
   141 * Theory Divides: Discontinued redundant theorems about div and mod.
   142 INCOMPATIBILITY, use the corresponding generic theorems instead.
   143 
   144   DIVISION_BY_ZERO ~> div_by_0, mod_by_0
   145   zdiv_self ~> div_self
   146   zmod_self ~> mod_self
   147   zdiv_zero ~> div_0
   148   zmod_zero ~> mod_0
   149   zdiv_zmod_equality ~> div_mod_equality2
   150   zdiv_zmod_equality2 ~> div_mod_equality
   151   zmod_zdiv_trivial ~> mod_div_trivial
   152   zdiv_zminus_zminus ~> div_minus_minus
   153   zmod_zminus_zminus ~> mod_minus_minus
   154   zdiv_zminus2 ~> div_minus_right
   155   zmod_zminus2 ~> mod_minus_right
   156   zdiv_minus1_right ~> div_minus1_right
   157   zmod_minus1_right ~> mod_minus1_right
   158   zdvd_mult_div_cancel ~> dvd_mult_div_cancel
   159   zmod_zmult1_eq ~> mod_mult_right_eq
   160   zpower_zmod ~> power_mod
   161   zdvd_zmod ~> dvd_mod
   162   zdvd_zmod_imp_zdvd ~> dvd_mod_imp_dvd
   163   mod_mult_distrib ~> mult_mod_left
   164   mod_mult_distrib2 ~> mult_mod_right
   165 
   166 * More default pred/set conversions on a couple of relation operations
   167 and predicates.  Consolidation of some relation theorems:
   168 
   169   converse_def ~> converse_unfold
   170   rel_comp_def ~> rel_comp_unfold
   171   symp_def ~> (dropped, use symp_def and sym_def instead)
   172   transp_def ~> transp_trans
   173   Domain_def ~> Domain_unfold
   174   Range_def ~> Domain_converse [symmetric]
   175 
   176 Generalized theorems INF_INT_eq, INF_INT_eq2, SUP_UN_eq, SUP_UN_eq2.
   177 
   178 See theory "Relation" for examples for making use of pred/set conversions
   179 by means of attributes "to_set" and "to_pred".
   180 
   181 INCOMPATIBILITY.
   182 
   183 * Consolidated various theorem names relating to Finite_Set.fold
   184 combinator:
   185 
   186   inf_INFI_fold_inf ~> inf_INF_fold_inf
   187   sup_SUPR_fold_sup ~> sup_SUP_fold_sup
   188   INFI_fold_inf ~> INF_fold_inf
   189   SUPR_fold_sup ~> SUP_fold_sup
   190   union_set ~> union_set_fold
   191   minus_set ~> minus_set_fold
   192 
   193 INCOMPATIBILITY.
   194 
   195 * Consolidated theorem names concerning fold combinators:
   196 
   197   INFI_set_fold ~> INF_set_fold
   198   SUPR_set_fold ~> SUP_set_fold
   199   INF_code ~> INF_set_foldr
   200   SUP_code ~> SUP_set_foldr
   201   foldr.simps ~> foldr_Nil foldr_Cons (in point-free formulation)
   202   foldl.simps ~> foldl_Nil foldl_Cons
   203   foldr_fold_rev ~> foldr_def
   204   foldl_fold ~> foldl_def
   205 
   206 INCOMPATIBILITY.
   207 
   208 * Dropped rarely useful theorems concerning fold combinators:
   209 foldl_apply, foldl_fun_comm, foldl_rev, fold_weak_invariant,
   210 rev_foldl_cons, fold_set_remdups, fold_set, fold_set1,
   211 concat_conv_foldl, foldl_weak_invariant, foldl_invariant,
   212 foldr_invariant, foldl_absorb0, foldl_foldr1_lemma, foldl_foldr1,
   213 listsum_conv_fold, listsum_foldl, sort_foldl_insort.  INCOMPATIBILITY.
   214 Prefer "List.fold" with canonical argument order, or boil down
   215 "List.foldr" and "List.foldl" to "List.fold" by unfolding "foldr_def"
   216 and "foldl_def".  For the common phrases "%xs. List.foldr plus xs 0"
   217 and "List.foldl plus 0", prefer "List.listsum".
   218 
   219 * Congruence rules Option.map_cong and Option.bind_cong for recursion
   220 through option types.
   221 
   222 * Concrete syntax for case expressions includes constraints for source
   223 positions, and thus produces Prover IDE markup for its bindings.
   224 INCOMPATIBILITY for old-style syntax translations that augment the
   225 pattern notation; e.g. see src/HOL/HOLCF/One.thy for translations of
   226 one_case.
   227 
   228 * Discontinued configuration option "syntax_positions": atomic terms
   229 in parse trees are always annotated by position constraints.
   230 
   231 * Finite_Set.fold now qualified.  INCOMPATIBILITY.
   232 
   233 * Renamed some facts on canonical fold on lists, in order to avoid
   234 problems with interpretation involving corresponding facts on foldl
   235 with the same base names:
   236 
   237   fold_set_remdups ~> fold_set_fold_remdups
   238   fold_set ~> fold_set_fold
   239   fold1_set ~> fold1_set_fold
   240 
   241 INCOMPATIBILITY.
   242 
   243 * Renamed facts about the power operation on relations, i.e., relpow
   244   to match the constant's name:
   245   
   246   rel_pow_1 ~> relpow_1
   247   rel_pow_0_I ~> relpow_0_I
   248   rel_pow_Suc_I ~> relpow_Suc_I
   249   rel_pow_Suc_I2 ~> relpow_Suc_I2
   250   rel_pow_0_E ~> relpow_0_E
   251   rel_pow_Suc_E ~> relpow_Suc_E
   252   rel_pow_E ~> relpow_E
   253   rel_pow_Suc_D2 ~> relpow_Suc_D2
   254   rel_pow_Suc_E2 ~> relpow_Suc_E2 
   255   rel_pow_Suc_D2' ~> relpow_Suc_D2'
   256   rel_pow_E2 ~> relpow_E2
   257   rel_pow_add ~> relpow_add
   258   rel_pow_commute ~> relpow
   259   rel_pow_empty ~> relpow_empty:
   260   rtrancl_imp_UN_rel_pow ~> rtrancl_imp_UN_relpow
   261   rel_pow_imp_rtrancl ~> relpow_imp_rtrancl
   262   rtrancl_is_UN_rel_pow ~> rtrancl_is_UN_relpow
   263   rtrancl_imp_rel_pow ~> rtrancl_imp_relpow
   264   rel_pow_fun_conv ~> relpow_fun_conv
   265   rel_pow_finite_bounded1 ~> relpow_finite_bounded1
   266   rel_pow_finite_bounded ~> relpow_finite_bounded
   267   rtrancl_finite_eq_rel_pow ~> rtrancl_finite_eq_relpow
   268   trancl_finite_eq_rel_pow ~> trancl_finite_eq_relpow
   269   single_valued_rel_pow ~> single_valued_relpow
   270  
   271 INCOMPATIBILITY.
   272 
   273 * New theory HOL/Library/DAList provides an abstract type for association
   274   lists with distinct keys.
   275 
   276 * 'datatype' specifications allow explicit sort constraints.
   277 
   278 * Theory HOL/Library/Diagonalize has been removed. INCOMPATIBILITY,
   279 use theory HOL/Library/Nat_Bijection instead.
   280 
   281 * Session HOL-Word: Discontinued many redundant theorems specific to
   282 type 'a word. INCOMPATIBILITY, use the corresponding generic theorems
   283 instead.
   284 
   285   word_sub_alt ~> word_sub_wi
   286   word_add_alt ~> word_add_def
   287   word_mult_alt ~> word_mult_def
   288   word_minus_alt ~> word_minus_def
   289   word_0_alt ~> word_0_wi
   290   word_1_alt ~> word_1_wi
   291   word_add_0 ~> add_0_left
   292   word_add_0_right ~> add_0_right
   293   word_mult_1 ~> mult_1_left
   294   word_mult_1_right ~> mult_1_right
   295   word_add_commute ~> add_commute
   296   word_add_assoc ~> add_assoc
   297   word_add_left_commute ~> add_left_commute
   298   word_mult_commute ~> mult_commute
   299   word_mult_assoc ~> mult_assoc
   300   word_mult_left_commute ~> mult_left_commute
   301   word_left_distrib ~> left_distrib
   302   word_right_distrib ~> right_distrib
   303   word_left_minus ~> left_minus
   304   word_diff_0_right ~> diff_0_right
   305   word_diff_self ~> diff_self
   306   word_sub_def ~> diff_minus
   307   word_diff_minus ~> diff_minus
   308   word_add_ac ~> add_ac
   309   word_mult_ac ~> mult_ac
   310   word_plus_ac0 ~> add_0_left add_0_right add_ac
   311   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
   312   word_order_trans ~> order_trans
   313   word_order_refl ~> order_refl
   314   word_order_antisym ~> order_antisym
   315   word_order_linear ~> linorder_linear
   316   lenw1_zero_neq_one ~> zero_neq_one
   317   word_number_of_eq ~> number_of_eq
   318   word_of_int_add_hom ~> wi_hom_add
   319   word_of_int_sub_hom ~> wi_hom_sub
   320   word_of_int_mult_hom ~> wi_hom_mult
   321   word_of_int_minus_hom ~> wi_hom_neg
   322   word_of_int_succ_hom ~> wi_hom_succ
   323   word_of_int_pred_hom ~> wi_hom_pred
   324   word_of_int_0_hom ~> word_0_wi
   325   word_of_int_1_hom ~> word_1_wi
   326 
   327 * Clarified attribute "mono_set": pure declaration without modifying
   328 the result of the fact expression.
   329 
   330 * "Transitive_Closure.ntrancl": bounded transitive closure on
   331 relations.
   332 
   333 * Constant "Set.not_member" now qualified.  INCOMPATIBILITY.
   334 
   335 * "sublists" moved to theory More_List.  INCOMPATIBILITY.
   336 
   337 * Theory Int: Discontinued many legacy theorems specific to type int.
   338 INCOMPATIBILITY, use the corresponding generic theorems instead.
   339 
   340   zminus_zminus ~> minus_minus
   341   zminus_0 ~> minus_zero
   342   zminus_zadd_distrib ~> minus_add_distrib
   343   zadd_commute ~> add_commute
   344   zadd_assoc ~> add_assoc
   345   zadd_left_commute ~> add_left_commute
   346   zadd_ac ~> add_ac
   347   zmult_ac ~> mult_ac
   348   zadd_0 ~> add_0_left
   349   zadd_0_right ~> add_0_right
   350   zadd_zminus_inverse2 ~> left_minus
   351   zmult_zminus ~> mult_minus_left
   352   zmult_commute ~> mult_commute
   353   zmult_assoc ~> mult_assoc
   354   zadd_zmult_distrib ~> left_distrib
   355   zadd_zmult_distrib2 ~> right_distrib
   356   zdiff_zmult_distrib ~> left_diff_distrib
   357   zdiff_zmult_distrib2 ~> right_diff_distrib
   358   zmult_1 ~> mult_1_left
   359   zmult_1_right ~> mult_1_right
   360   zle_refl ~> order_refl
   361   zle_trans ~> order_trans
   362   zle_antisym ~> order_antisym
   363   zle_linear ~> linorder_linear
   364   zless_linear ~> linorder_less_linear
   365   zadd_left_mono ~> add_left_mono
   366   zadd_strict_right_mono ~> add_strict_right_mono
   367   zadd_zless_mono ~> add_less_le_mono
   368   int_0_less_1 ~> zero_less_one
   369   int_0_neq_1 ~> zero_neq_one
   370   zless_le ~> less_le
   371   zpower_zadd_distrib ~> power_add
   372   zero_less_zpower_abs_iff ~> zero_less_power_abs_iff
   373   zero_le_zpower_abs ~> zero_le_power_abs
   374 
   375 * Theory Deriv: Renamed
   376 
   377   DERIV_nonneg_imp_nonincreasing ~> DERIV_nonneg_imp_nondecreasing
   378 
   379 * New "case_product" attribute to generate a case rule doing multiple
   380 case distinctions at the same time.  E.g.
   381 
   382   list.exhaust [case_product nat.exhaust]
   383 
   384 produces a rule which can be used to perform case distinction on both
   385 a list and a nat.
   386 
   387 * Improved code generation of multisets.
   388 
   389 * New diagnostic command find_unused_assms to find potentially superfluous
   390   assumptions in theorems using Quickcheck.
   391 
   392 * Quickcheck:
   393   - Quickcheck returns variable assignments as counterexamples, which
   394     allows to reveal the underspecification of functions under test.
   395     For example, refuting "hd xs = x", it presents the variable
   396     assignment xs = [] and x = a1 as a counterexample, assuming that
   397     any property is false whenever "hd []" occurs in it.
   398     These counterexample are marked as potentially spurious, as
   399     Quickcheck also returns "xs = []" as a counterexample to the
   400     obvious theorem "hd xs = hd xs".
   401     After finding a potentially spurious counterexample, Quickcheck
   402     continues searching for genuine ones.
   403     By default, Quickcheck shows potentially spurious and genuine
   404     counterexamples. The option "genuine_only" sets quickcheck to
   405     only show genuine counterexamples.
   406 
   407   - The command 'quickcheck_generator' creates random and exhaustive
   408     value generators for a given type and operations.
   409     It generates values by using the operations as if they were
   410     constructors of that type. 
   411 
   412   - Support for multisets.
   413 
   414   - Added "use_subtype" options.
   415  
   416 * Nitpick:
   417   - Fixed infinite loop caused by the 'peephole_optim' option and
   418     affecting 'rat' and 'real'.
   419 
   420 * Sledgehammer:
   421   - Added "lam_trans", "uncurry_aliases", and "minimize" options.
   422   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   423   - Renamed "sound" option to "strict".
   424 
   425 * Metis:
   426   - Added possibility to specify lambda translations scheme as a
   427     parenthesized argument (e.g., "by (metis (lifting) ...)").
   428 
   429 * Command 'try0':
   430   - Renamed from 'try_methods'. INCOMPATIBILITY.
   431 
   432 * New "eventually_elim" method as a generalized variant of the
   433   eventually_elim* rules. Supports structured proofs.
   434 
   435 
   436 *** FOL ***
   437 
   438 * New "case_product" attribute (see HOL).
   439 
   440 
   441 *** ML ***
   442 
   443 * Antiquotation @{keyword "name"} produces a parser for outer syntax
   444 from a minor keyword introduced via theory header declaration.
   445 
   446 * Antiquotation @{command_spec "name"} produces the
   447 Outer_Syntax.command_spec from a major keyword introduced via theory
   448 header declaration; it can be passed to Outer_Syntax.command etc.
   449 
   450 * Local_Theory.define no longer hard-wires default theorem name
   451 "foo_def", but retains the binding as given.  If that is Binding.empty
   452 / Attrib.empty_binding, the result is not registered as user-level
   453 fact.  The Local_Theory.define_internal variant allows to specify a
   454 non-empty name (used for the foundation in the background theory),
   455 while omitting the fact binding in the user-context.  Potential
   456 INCOMPATIBILITY for derived definitional packages: need to specify
   457 naming policy for primitive definitions more explicitly.
   458 
   459 * Renamed Thm.capply to Thm.apply, and Thm.cabs to Thm.lambda in
   460 conformance with similar operations in structure Term and Logic.
   461 
   462 * Antiquotation @{attributes [...]} embeds attribute source
   463 representation into the ML text, which is particularly useful with
   464 declarations like Local_Theory.note.
   465 
   466 * Structure Proof_Context follows standard naming scheme.  Old
   467 ProofContext has been discontinued.  INCOMPATIBILITY.
   468 
   469 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
   470 change of semantics: update is applied to auxiliary local theory
   471 context as well.
   472 
   473 * Modernized some old-style infix operations:
   474 
   475   addeqcongs    ~> Simplifier.add_eqcong
   476   deleqcongs    ~> Simplifier.del_eqcong
   477   addcongs      ~> Simplifier.add_cong
   478   delcongs      ~> Simplifier.del_cong
   479   setmksimps    ~> Simplifier.set_mksimps
   480   setmkcong     ~> Simplifier.set_mkcong
   481   setmksym      ~> Simplifier.set_mksym
   482   setmkeqTrue   ~> Simplifier.set_mkeqTrue
   483   settermless   ~> Simplifier.set_termless
   484   setsubgoaler  ~> Simplifier.set_subgoaler
   485   addsplits     ~> Splitter.add_split
   486   delsplits     ~> Splitter.del_split
   487 
   488 
   489 
   490 New in Isabelle2011-1 (October 2011)
   491 ------------------------------------
   492 
   493 *** General ***
   494 
   495 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
   496 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
   497 
   498   - Management of multiple theory files directly from the editor
   499     buffer store -- bypassing the file-system (no requirement to save
   500     files for checking).
   501 
   502   - Markup of formal entities within the text buffer, with semantic
   503     highlighting, tooltips and hyperlinks to jump to defining source
   504     positions.
   505 
   506   - Improved text rendering, with sub/superscripts in the source
   507     buffer (including support for copy/paste wrt. output panel, HTML
   508     theory output and other non-Isabelle text boxes).
   509 
   510   - Refined scheduling of proof checking and printing of results,
   511     based on interactive editor view.  (Note: jEdit folding and
   512     narrowing allows to restrict buffer perspectives explicitly.)
   513 
   514   - Reduced CPU performance requirements, usable on machines with few
   515     cores.
   516 
   517   - Reduced memory requirements due to pruning of unused document
   518     versions (garbage collection).
   519 
   520 See also ~~/src/Tools/jEdit/README.html for further information,
   521 including some remaining limitations.
   522 
   523 * Theory loader: source files are exclusively located via the master
   524 directory of each theory node (where the .thy file itself resides).
   525 The global load path (such as src/HOL/Library) has been discontinued.
   526 Note that the path element ~~ may be used to reference theories in the
   527 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
   528 INCOMPATIBILITY.
   529 
   530 * Theory loader: source files are identified by content via SHA1
   531 digests.  Discontinued former path/modtime identification and optional
   532 ISABELLE_FILE_IDENT plugin scripts.
   533 
   534 * Parallelization of nested Isar proofs is subject to
   535 Goal.parallel_proofs_threshold (default 100).  See also isabelle
   536 usedir option -Q.
   537 
   538 * Name space: former unsynchronized references are now proper
   539 configuration options, with more conventional names:
   540 
   541   long_names   ~> names_long
   542   short_names  ~> names_short
   543   unique_names ~> names_unique
   544 
   545 Minor INCOMPATIBILITY, need to declare options in context like this:
   546 
   547   declare [[names_unique = false]]
   548 
   549 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
   550 that the result needs to be unique, which means fact specifications
   551 may have to be refined after enriching a proof context.
   552 
   553 * Attribute "case_names" has been refined: the assumptions in each case
   554 can be named now by following the case name with [name1 name2 ...].
   555 
   556 * Isabelle/Isar reference manual has been updated and extended:
   557   - "Synopsis" provides a catalog of main Isar language concepts.
   558   - Formal references in syntax diagrams, via @{rail} antiquotation.
   559   - Updated material from classic "ref" manual, notably about
   560     "Classical Reasoner".
   561 
   562 
   563 *** HOL ***
   564 
   565 * Class bot and top require underlying partial order rather than
   566 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
   567 
   568 * Class complete_lattice: generalized a couple of lemmas from sets;
   569 generalized theorems INF_cong and SUP_cong.  New type classes for
   570 complete boolean algebras and complete linear orders.  Lemmas
   571 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
   572 class complete_linorder.
   573 
   574 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
   575 Sup_fun_def, Inf_apply, Sup_apply.
   576 
   577 Removed redundant lemmas (the right hand side gives hints how to
   578 replace them for (metis ...), or (simp only: ...) proofs):
   579 
   580   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
   581   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
   582   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
   583   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
   584   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
   585   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
   586   Inter_def ~> INF_def, image_def
   587   Union_def ~> SUP_def, image_def
   588   INT_eq ~> INF_def, and image_def
   589   UN_eq ~> SUP_def, and image_def
   590   INF_subset ~> INF_superset_mono [OF _ order_refl]
   591 
   592 More consistent and comprehensive names:
   593 
   594   INTER_eq_Inter_image ~> INF_def
   595   UNION_eq_Union_image ~> SUP_def
   596   INFI_def ~> INF_def
   597   SUPR_def ~> SUP_def
   598   INF_leI ~> INF_lower
   599   INF_leI2 ~> INF_lower2
   600   le_INFI ~> INF_greatest
   601   le_SUPI ~> SUP_upper
   602   le_SUPI2 ~> SUP_upper2
   603   SUP_leI ~> SUP_least
   604   INFI_bool_eq ~> INF_bool_eq
   605   SUPR_bool_eq ~> SUP_bool_eq
   606   INFI_apply ~> INF_apply
   607   SUPR_apply ~> SUP_apply
   608   INTER_def ~> INTER_eq
   609   UNION_def ~> UNION_eq
   610 
   611 INCOMPATIBILITY.
   612 
   613 * Renamed theory Complete_Lattice to Complete_Lattices.
   614 INCOMPATIBILITY.
   615 
   616 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
   617 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
   618 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
   619 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
   620 
   621 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
   622 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
   623 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
   624 INCOMPATIBILITY.
   625 
   626 * Added syntactic classes "inf" and "sup" for the respective
   627 constants.  INCOMPATIBILITY: Changes in the argument order of the
   628 (mostly internal) locale predicates for some derived classes.
   629 
   630 * Theorem collections ball_simps and bex_simps do not contain theorems
   631 referring to UNION any longer; these have been moved to collection
   632 UN_ball_bex_simps.  INCOMPATIBILITY.
   633 
   634 * Theory Archimedean_Field: floor now is defined as parameter of a
   635 separate type class floor_ceiling.
   636 
   637 * Theory Finite_Set: more coherent development of fold_set locales:
   638 
   639     locale fun_left_comm ~> locale comp_fun_commute
   640     locale fun_left_comm_idem ~> locale comp_fun_idem
   641 
   642 Both use point-free characterization; interpretation proofs may need
   643 adjustment.  INCOMPATIBILITY.
   644 
   645 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
   646 accordance with standard mathematical terminology. INCOMPATIBILITY.
   647 
   648 * Theory Complex_Main: The locale interpretations for the
   649 bounded_linear and bounded_bilinear locales have been removed, in
   650 order to reduce the number of duplicate lemmas. Users must use the
   651 original names for distributivity theorems, potential INCOMPATIBILITY.
   652 
   653   divide.add ~> add_divide_distrib
   654   divide.diff ~> diff_divide_distrib
   655   divide.setsum ~> setsum_divide_distrib
   656   mult.add_right ~> right_distrib
   657   mult.diff_right ~> right_diff_distrib
   658   mult_right.setsum ~> setsum_right_distrib
   659   mult_left.diff ~> left_diff_distrib
   660 
   661 * Theory Complex_Main: Several redundant theorems have been removed or
   662 replaced by more general versions. INCOMPATIBILITY.
   663 
   664   real_diff_def ~> minus_real_def
   665   real_divide_def ~> divide_real_def
   666   real_less_def ~> less_le
   667   real_abs_def ~> abs_real_def
   668   real_sgn_def ~> sgn_real_def
   669   real_mult_commute ~> mult_commute
   670   real_mult_assoc ~> mult_assoc
   671   real_mult_1 ~> mult_1_left
   672   real_add_mult_distrib ~> left_distrib
   673   real_zero_not_eq_one ~> zero_neq_one
   674   real_mult_inverse_left ~> left_inverse
   675   INVERSE_ZERO ~> inverse_zero
   676   real_le_refl ~> order_refl
   677   real_le_antisym ~> order_antisym
   678   real_le_trans ~> order_trans
   679   real_le_linear ~> linear
   680   real_le_eq_diff ~> le_iff_diff_le_0
   681   real_add_left_mono ~> add_left_mono
   682   real_mult_order ~> mult_pos_pos
   683   real_mult_less_mono2 ~> mult_strict_left_mono
   684   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
   685   real_0_le_divide_iff ~> zero_le_divide_iff
   686   realpow_two_disj ~> power2_eq_iff
   687   real_squared_diff_one_factored ~> square_diff_one_factored
   688   realpow_two_diff ~> square_diff_square_factored
   689   reals_complete2 ~> complete_real
   690   real_sum_squared_expand ~> power2_sum
   691   exp_ln_eq ~> ln_unique
   692   expi_add ~> exp_add
   693   expi_zero ~> exp_zero
   694   lemma_DERIV_subst ~> DERIV_cong
   695   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
   696   LIMSEQ_const ~> tendsto_const
   697   LIMSEQ_norm ~> tendsto_norm
   698   LIMSEQ_add ~> tendsto_add
   699   LIMSEQ_minus ~> tendsto_minus
   700   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
   701   LIMSEQ_diff ~> tendsto_diff
   702   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
   703   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
   704   LIMSEQ_mult ~> tendsto_mult
   705   LIMSEQ_inverse ~> tendsto_inverse
   706   LIMSEQ_divide ~> tendsto_divide
   707   LIMSEQ_pow ~> tendsto_power
   708   LIMSEQ_setsum ~> tendsto_setsum
   709   LIMSEQ_setprod ~> tendsto_setprod
   710   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
   711   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
   712   LIMSEQ_imp_rabs ~> tendsto_rabs
   713   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
   714   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
   715   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
   716   LIMSEQ_Complex ~> tendsto_Complex
   717   LIM_ident ~> tendsto_ident_at
   718   LIM_const ~> tendsto_const
   719   LIM_add ~> tendsto_add
   720   LIM_add_zero ~> tendsto_add_zero
   721   LIM_minus ~> tendsto_minus
   722   LIM_diff ~> tendsto_diff
   723   LIM_norm ~> tendsto_norm
   724   LIM_norm_zero ~> tendsto_norm_zero
   725   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
   726   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
   727   LIM_rabs ~> tendsto_rabs
   728   LIM_rabs_zero ~> tendsto_rabs_zero
   729   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
   730   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
   731   LIM_compose ~> tendsto_compose
   732   LIM_mult ~> tendsto_mult
   733   LIM_scaleR ~> tendsto_scaleR
   734   LIM_of_real ~> tendsto_of_real
   735   LIM_power ~> tendsto_power
   736   LIM_inverse ~> tendsto_inverse
   737   LIM_sgn ~> tendsto_sgn
   738   isCont_LIM_compose ~> isCont_tendsto_compose
   739   bounded_linear.LIM ~> bounded_linear.tendsto
   740   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
   741   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
   742   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
   743   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
   744   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
   745   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
   746 
   747 * Theory Complex_Main: The definition of infinite series was
   748 generalized.  Now it is defined on the type class {topological_space,
   749 comm_monoid_add}.  Hence it is useable also for extended real numbers.
   750 
   751 * Theory Complex_Main: The complex exponential function "expi" is now
   752 a type-constrained abbreviation for "exp :: complex => complex"; thus
   753 several polymorphic lemmas about "exp" are now applicable to "expi".
   754 
   755 * Code generation:
   756 
   757   - Theory Library/Code_Char_ord provides native ordering of
   758     characters in the target language.
   759 
   760   - Commands code_module and code_library are legacy, use export_code
   761     instead.
   762 
   763   - Method "evaluation" is legacy, use method "eval" instead.
   764 
   765   - Legacy evaluator "SML" is deactivated by default.  May be
   766     reactivated by the following theory command:
   767 
   768       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   769 
   770 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   771 
   772 * New proof method "induction" that gives induction hypotheses the
   773 name "IH", thus distinguishing them from further hypotheses that come
   774 from rule induction.  The latter are still called "hyps".  Method
   775 "induction" is a thin wrapper around "induct" and follows the same
   776 syntax.
   777 
   778 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
   779 still available as a legacy feature for some time.
   780 
   781 * Nitpick:
   782   - Added "need" and "total_consts" options.
   783   - Reintroduced "show_skolems" option by popular demand.
   784   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   785     INCOMPATIBILITY.
   786 
   787 * Sledgehammer:
   788   - Use quasi-sound (and efficient) translations by default.
   789   - Added support for the following provers: E-ToFoF, LEO-II,
   790     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
   791   - Automatically preplay and minimize proofs before showing them if
   792     this can be done within reasonable time.
   793   - sledgehammer available_provers ~> sledgehammer supported_provers.
   794     INCOMPATIBILITY.
   795   - Added "preplay_timeout", "slicing", "type_enc", "sound",
   796     "max_mono_iters", and "max_new_mono_instances" options.
   797   - Removed "explicit_apply" and "full_types" options as well as "Full
   798     Types" Proof General menu item. INCOMPATIBILITY.
   799 
   800 * Metis:
   801   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   802   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
   803     INCOMPATIBILITY.
   804 
   805 * Command 'try':
   806   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
   807     "elim:" options. INCOMPATIBILITY.
   808   - Introduced 'try' that not only runs 'try_methods' but also
   809     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
   810 
   811 * Quickcheck:
   812   - Added "eval" option to evaluate terms for the found counterexample
   813     (currently only supported by the default (exhaustive) tester).
   814   - Added post-processing of terms to obtain readable counterexamples
   815     (currently only supported by the default (exhaustive) tester).
   816   - New counterexample generator quickcheck[narrowing] enables
   817     narrowing-based testing.  Requires the Glasgow Haskell compiler
   818     with its installation location defined in the Isabelle settings
   819     environment as ISABELLE_GHC.
   820   - Removed quickcheck tester "SML" based on the SML code generator
   821     (formly in HOL/Library).
   822 
   823 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
   824 use 'partial_function' instead.
   825 
   826 * Theory Library/Extended_Reals replaces now the positive extended
   827 reals found in probability theory. This file is extended by
   828 Multivariate_Analysis/Extended_Real_Limits.
   829 
   830 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
   831 from where it must be imported explicitly if it is really required.
   832 INCOMPATIBILITY.
   833 
   834 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
   835 been moved here.  INCOMPATIBILITY.
   836 
   837 * Theory Library/Saturated provides type of numbers with saturated
   838 arithmetic.
   839 
   840 * Theory Library/Product_Lattice defines a pointwise ordering for the
   841 product type 'a * 'b, and provides instance proofs for various order
   842 and lattice type classes.
   843 
   844 * Theory Library/Countable now provides the "countable_datatype" proof
   845 method for proving "countable" class instances for datatypes.
   846 
   847 * Theory Library/Cset_Monad allows do notation for computable sets
   848 (cset) via the generic monad ad-hoc overloading facility.
   849 
   850 * Library: Theories of common data structures are split into theories
   851 for implementation, an invariant-ensuring type, and connection to an
   852 abstract type. INCOMPATIBILITY.
   853 
   854   - RBT is split into RBT and RBT_Mapping.
   855   - AssocList is split and renamed into AList and AList_Mapping.
   856   - DList is split into DList_Impl, DList, and DList_Cset.
   857   - Cset is split into Cset and List_Cset.
   858 
   859 * Theory Library/Nat_Infinity has been renamed to
   860 Library/Extended_Nat, with name changes of the following types and
   861 constants:
   862 
   863   type inat   ~> type enat
   864   Fin         ~> enat
   865   Infty       ~> infinity (overloaded)
   866   iSuc        ~> eSuc
   867   the_Fin     ~> the_enat
   868 
   869 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   870 been renamed accordingly. INCOMPATIBILITY.
   871 
   872 * Session Multivariate_Analysis: The euclidean_space type class now
   873 fixes a constant "Basis :: 'a set" consisting of the standard
   874 orthonormal basis for the type. Users now have the option of
   875 quantifying over this set instead of using the "basis" function, e.g.
   876 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
   877 
   878 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   879 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   880 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   881 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   882 changed to match. Definition theorems for overloaded constants now use
   883 the standard "foo_vec_def" naming scheme. A few other theorems have
   884 been renamed as follows (INCOMPATIBILITY):
   885 
   886   Cart_eq          ~> vec_eq_iff
   887   dist_nth_le_cart ~> dist_vec_nth_le
   888   tendsto_vector   ~> vec_tendstoI
   889   Cauchy_vector    ~> vec_CauchyI
   890 
   891 * Session Multivariate_Analysis: Several duplicate theorems have been
   892 removed, and other theorems have been renamed or replaced with more
   893 general versions. INCOMPATIBILITY.
   894 
   895   finite_choice ~> finite_set_choice
   896   eventually_conjI ~> eventually_conj
   897   eventually_and ~> eventually_conj_iff
   898   eventually_false ~> eventually_False
   899   setsum_norm ~> norm_setsum
   900   Lim_sequentially ~> LIMSEQ_def
   901   Lim_ident_at ~> LIM_ident
   902   Lim_const ~> tendsto_const
   903   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
   904   Lim_neg ~> tendsto_minus
   905   Lim_add ~> tendsto_add
   906   Lim_sub ~> tendsto_diff
   907   Lim_mul ~> tendsto_scaleR
   908   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
   909   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
   910   Lim_linear ~> bounded_linear.tendsto
   911   Lim_component ~> tendsto_euclidean_component
   912   Lim_component_cart ~> tendsto_vec_nth
   913   Lim_inner ~> tendsto_inner [OF tendsto_const]
   914   dot_lsum ~> inner_setsum_left
   915   dot_rsum ~> inner_setsum_right
   916   continuous_cmul ~> continuous_scaleR [OF continuous_const]
   917   continuous_neg ~> continuous_minus
   918   continuous_sub ~> continuous_diff
   919   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
   920   continuous_mul ~> continuous_scaleR
   921   continuous_inv ~> continuous_inverse
   922   continuous_at_within_inv ~> continuous_at_within_inverse
   923   continuous_at_inv ~> continuous_at_inverse
   924   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
   925   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
   926   continuous_at_component ~> continuous_component [OF continuous_at_id]
   927   continuous_on_neg ~> continuous_on_minus
   928   continuous_on_sub ~> continuous_on_diff
   929   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
   930   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
   931   continuous_on_mul ~> continuous_on_scaleR
   932   continuous_on_mul_real ~> continuous_on_mult
   933   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
   934   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
   935   continuous_on_inverse ~> continuous_on_inv
   936   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
   937   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
   938   subset_interior ~> interior_mono
   939   subset_closure ~> closure_mono
   940   closure_univ ~> closure_UNIV
   941   real_arch_lt ~> reals_Archimedean2
   942   real_arch ~> reals_Archimedean3
   943   real_abs_norm ~> abs_norm_cancel
   944   real_abs_sub_norm ~> norm_triangle_ineq3
   945   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
   946 
   947 * Session HOL-Probability:
   948   - Caratheodory's extension lemma is now proved for ring_of_sets.
   949   - Infinite products of probability measures are now available.
   950   - Sigma closure is independent, if the generator is independent
   951   - Use extended reals instead of positive extended
   952     reals. INCOMPATIBILITY.
   953 
   954 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
   955 
   956   expand_fun_below ~> fun_below_iff
   957   below_fun_ext ~> fun_belowI
   958   expand_cfun_eq ~> cfun_eq_iff
   959   ext_cfun ~> cfun_eqI
   960   expand_cfun_below ~> cfun_below_iff
   961   below_cfun_ext ~> cfun_belowI
   962   monofun_fun_fun ~> fun_belowD
   963   monofun_fun_arg ~> monofunE
   964   monofun_lub_fun ~> adm_monofun [THEN admD]
   965   cont_lub_fun ~> adm_cont [THEN admD]
   966   cont2cont_Rep_CFun ~> cont2cont_APP
   967   cont_Rep_CFun_app ~> cont_APP_app
   968   cont_Rep_CFun_app_app ~> cont_APP_app_app
   969   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
   970   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
   971   contlub_cfun ~> lub_APP [symmetric]
   972   contlub_LAM ~> lub_LAM [symmetric]
   973   thelubI ~> lub_eqI
   974   UU_I ~> bottomI
   975   lift_distinct1 ~> lift.distinct(1)
   976   lift_distinct2 ~> lift.distinct(2)
   977   Def_not_UU ~> lift.distinct(2)
   978   Def_inject ~> lift.inject
   979   below_UU_iff ~> below_bottom_iff
   980   eq_UU_iff ~> eq_bottom_iff
   981 
   982 
   983 *** Document preparation ***
   984 
   985 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   986 isar-ref manual, both for description and actual application of the
   987 same.
   988 
   989 * Antiquotation @{value} evaluates the given term and presents its
   990 result.
   991 
   992 * Antiquotations: term style "isub" provides ad-hoc conversion of
   993 variables x1, y23 into subscripted form x\<^isub>1,
   994 y\<^isub>2\<^isub>3.
   995 
   996 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   997 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   998 
   999 * Localized \isabellestyle switch can be used within blocks or groups
  1000 like this:
  1001 
  1002   \isabellestyle{it}  %preferred default
  1003   {\isabellestylett @{text "typewriter stuff"}}
  1004 
  1005 * Discontinued special treatment of hard tabulators.  Implicit
  1006 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
  1007 layouts.
  1008 
  1009 
  1010 *** ML ***
  1011 
  1012 * The inner syntax of sort/type/term/prop supports inlined YXML
  1013 representations within quoted string tokens.  By encoding logical
  1014 entities via Term_XML (in ML or Scala) concrete syntax can be
  1015 bypassed, which is particularly useful for producing bits of text
  1016 under external program control.
  1017 
  1018 * Antiquotations for ML and document preparation are managed as theory
  1019 data, which requires explicit setup.
  1020 
  1021 * Isabelle_Process.is_active allows tools to check if the official
  1022 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
  1023 (better known as Proof General).
  1024 
  1025 * Structure Proof_Context follows standard naming scheme.  Old
  1026 ProofContext is still available for some time as legacy alias.
  1027 
  1028 * Structure Timing provides various operations for timing; supersedes
  1029 former start_timing/end_timing etc.
  1030 
  1031 * Path.print is the official way to show file-system paths to users
  1032 (including quotes etc.).
  1033 
  1034 * Inner syntax: identifiers in parse trees of generic categories
  1035 "logic", "aprop", "idt" etc. carry position information (disguised as
  1036 type constraints).  Occasional INCOMPATIBILITY with non-compliant
  1037 translations that choke on unexpected type constraints.  Positions can
  1038 be stripped in ML translations via Syntax.strip_positions /
  1039 Syntax.strip_positions_ast, or via the syntax constant
  1040 "_strip_positions" within parse trees.  As last resort, positions can
  1041 be disabled via the configuration option Syntax.positions, which is
  1042 called "syntax_positions" in Isar attribute syntax.
  1043 
  1044 * Discontinued special status of various ML structures that contribute
  1045 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
  1046 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
  1047 refer directly to Ast.Constant, Lexicon.is_identifier,
  1048 Syntax_Trans.mk_binder_tr etc.
  1049 
  1050 * Typed print translation: discontinued show_sorts argument, which is
  1051 already available via context of "advanced" translation.
  1052 
  1053 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
  1054 goal states; body tactic needs to address all subgoals uniformly.
  1055 
  1056 * Slightly more special eq_list/eq_set, with shortcut involving
  1057 pointer equality (assumes that eq relation is reflexive).
  1058 
  1059 * Classical tactics use proper Proof.context instead of historic types
  1060 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
  1061 operate directly on Proof.context.  Raw type claset retains its use as
  1062 snapshot of the classical context, which can be recovered via
  1063 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
  1064 INCOMPATIBILITY, classical tactics and derived proof methods require
  1065 proper Proof.context.
  1066 
  1067 
  1068 *** System ***
  1069 
  1070 * Discontinued support for Poly/ML 5.2, which was the last version
  1071 without proper multithreading and TimeLimit implementation.
  1072 
  1073 * Discontinued old lib/scripts/polyml-platform, which has been
  1074 obsolete since Isabelle2009-2.
  1075 
  1076 * Various optional external tools are referenced more robustly and
  1077 uniformly by explicit Isabelle settings as follows:
  1078 
  1079   ISABELLE_CSDP   (formerly CSDP_EXE)
  1080   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  1081   ISABELLE_OCAML  (formerly EXEC_OCAML)
  1082   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  1083   ISABELLE_YAP    (formerly EXEC_YAP)
  1084 
  1085 Note that automated detection from the file-system or search path has
  1086 been discontinued.  INCOMPATIBILITY.
  1087 
  1088 * Scala layer provides JVM method invocation service for static
  1089 methods of type (String)String, see Invoke_Scala.method in ML.  For
  1090 example:
  1091 
  1092   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
  1093 
  1094 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
  1095 this allows to pass structured values between ML and Scala.
  1096 
  1097 * The IsabelleText fonts includes some further glyphs to support the
  1098 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
  1099 installed a local copy (which is normally *not* required) need to
  1100 delete or update it from ~~/lib/fonts/.
  1101 
  1102 
  1103 
  1104 New in Isabelle2011 (January 2011)
  1105 ----------------------------------
  1106 
  1107 *** General ***
  1108 
  1109 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
  1110 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
  1111 useful tooltips and hyperlinks produced from its static analysis.  The
  1112 bundled component provides an executable Isabelle tool that can be run
  1113 like this:
  1114 
  1115   Isabelle2011/bin/isabelle jedit
  1116 
  1117 * Significantly improved Isabelle/Isar implementation manual.
  1118 
  1119 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
  1120 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
  1121 while the default heap location within that directory lacks that extra
  1122 suffix.  This isolates multiple Isabelle installations from each
  1123 other, avoiding problems with old settings in new versions.
  1124 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
  1125 
  1126 * Source files are always encoded as UTF-8, instead of old-fashioned
  1127 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
  1128 the following package declarations:
  1129 
  1130   \usepackage[utf8]{inputenc}
  1131   \usepackage{textcomp}
  1132 
  1133 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
  1134 a Unicode character is treated as a single symbol, not a sequence of
  1135 non-ASCII bytes as before.  Since Isabelle/ML string literals may
  1136 contain symbols without further backslash escapes, Unicode can now be
  1137 used here as well.  Recall that Symbol.explode in ML provides a
  1138 consistent view on symbols, while raw explode (or String.explode)
  1139 merely give a byte-oriented representation.
  1140 
  1141 * Theory loader: source files are primarily located via the master
  1142 directory of each theory node (where the .thy file itself resides).
  1143 The global load path is still partially available as legacy feature.
  1144 Minor INCOMPATIBILITY due to subtle change in file lookup: use
  1145 explicit paths, relatively to the theory.
  1146 
  1147 * Special treatment of ML file names has been discontinued.
  1148 Historically, optional extensions .ML or .sml were added on demand --
  1149 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
  1150 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
  1151 
  1152 * Various options that affect pretty printing etc. are now properly
  1153 handled within the context via configuration options, instead of
  1154 unsynchronized references or print modes.  There are both ML Config.T
  1155 entities and Isar declaration attributes to access these.
  1156 
  1157   ML (Config.T)                 Isar (attribute)
  1158 
  1159   eta_contract                  eta_contract
  1160   show_brackets                 show_brackets
  1161   show_sorts                    show_sorts
  1162   show_types                    show_types
  1163   show_question_marks           show_question_marks
  1164   show_consts                   show_consts
  1165   show_abbrevs                  show_abbrevs
  1166 
  1167   Syntax.ast_trace              syntax_ast_trace
  1168   Syntax.ast_stat               syntax_ast_stat
  1169   Syntax.ambiguity_level        syntax_ambiguity_level
  1170 
  1171   Goal_Display.goals_limit      goals_limit
  1172   Goal_Display.show_main_goal   show_main_goal
  1173 
  1174   Method.rule_trace             rule_trace
  1175 
  1176   Thy_Output.display            thy_output_display
  1177   Thy_Output.quotes             thy_output_quotes
  1178   Thy_Output.indent             thy_output_indent
  1179   Thy_Output.source             thy_output_source
  1180   Thy_Output.break              thy_output_break
  1181 
  1182 Note that corresponding "..._default" references in ML may only be
  1183 changed globally at the ROOT session setup, but *not* within a theory.
  1184 The option "show_abbrevs" supersedes the former print mode
  1185 "no_abbrevs" with inverted meaning.
  1186 
  1187 * More systematic naming of some configuration options.
  1188 INCOMPATIBILITY.
  1189 
  1190   trace_simp  ~>  simp_trace
  1191   debug_simp  ~>  simp_debug
  1192 
  1193 * Support for real valued configuration options, using simplistic
  1194 floating-point notation that coincides with the inner syntax for
  1195 float_token.
  1196 
  1197 * Support for real valued preferences (with approximative PGIP type):
  1198 front-ends need to accept "pgint" values in float notation.
  1199 INCOMPATIBILITY.
  1200 
  1201 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
  1202 DejaVu Sans.
  1203 
  1204 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
  1205 
  1206 
  1207 *** Pure ***
  1208 
  1209 * Command 'type_synonym' (with single argument) replaces somewhat
  1210 outdated 'types', which is still available as legacy feature for some
  1211 time.
  1212 
  1213 * Command 'nonterminal' (with 'and' separated list of arguments)
  1214 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
  1215 
  1216 * Command 'notepad' replaces former 'example_proof' for
  1217 experimentation in Isar without any result.  INCOMPATIBILITY.
  1218 
  1219 * Locale interpretation commands 'interpret' and 'sublocale' accept
  1220 lists of equations to map definitions in a locale to appropriate
  1221 entities in the context of the interpretation.  The 'interpretation'
  1222 command already provided this functionality.
  1223 
  1224 * Diagnostic command 'print_dependencies' prints the locale instances
  1225 that would be activated if the specified expression was interpreted in
  1226 the current context.  Variant "print_dependencies!" assumes a context
  1227 without interpretations.
  1228 
  1229 * Diagnostic command 'print_interps' prints interpretations in proofs
  1230 in addition to interpretations in theories.
  1231 
  1232 * Discontinued obsolete 'global' and 'local' commands to manipulate
  1233 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
  1234 Sign.root_path and Sign.local_path may be applied directly where this
  1235 feature is still required for historical reasons.
  1236 
  1237 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
  1238 'definition' instead.
  1239 
  1240 * The "prems" fact, which refers to the accidental collection of
  1241 foundational premises in the context, is now explicitly marked as
  1242 legacy feature and will be discontinued soon.  Consider using "assms"
  1243 of the head statement or reference facts by explicit names.
  1244 
  1245 * Document antiquotations @{class} and @{type} print classes and type
  1246 constructors.
  1247 
  1248 * Document antiquotation @{file} checks file/directory entries within
  1249 the local file system.
  1250 
  1251 
  1252 *** HOL ***
  1253 
  1254 * Coercive subtyping: functions can be declared as coercions and type
  1255 inference will add them as necessary upon input of a term.  Theory
  1256 Complex_Main declares real :: nat => real and real :: int => real as
  1257 coercions. A coercion function f is declared like this:
  1258 
  1259   declare [[coercion f]]
  1260 
  1261 To lift coercions through type constructors (e.g. from nat => real to
  1262 nat list => real list), map functions can be declared, e.g.
  1263 
  1264   declare [[coercion_map map]]
  1265 
  1266 Currently coercion inference is activated only in theories including
  1267 real numbers, i.e. descendants of Complex_Main.  This is controlled by
  1268 the configuration option "coercion_enabled", e.g. it can be enabled in
  1269 other theories like this:
  1270 
  1271   declare [[coercion_enabled]]
  1272 
  1273 * Command 'partial_function' provides basic support for recursive
  1274 function definitions over complete partial orders.  Concrete instances
  1275 are provided for i) the option type, ii) tail recursion on arbitrary
  1276 types, and iii) the heap monad of Imperative_HOL.  See
  1277 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1278 for examples.
  1279 
  1280 * Function package: f.psimps rules are no longer implicitly declared
  1281 as [simp].  INCOMPATIBILITY.
  1282 
  1283 * Datatype package: theorems generated for executable equality (class
  1284 "eq") carry proper names and are treated as default code equations.
  1285 
  1286 * Inductive package: now offers command 'inductive_simps' to
  1287 automatically derive instantiated and simplified equations for
  1288 inductive predicates, similar to 'inductive_cases'.
  1289 
  1290 * Command 'enriched_type' allows to register properties of the
  1291 functorial structure of types.
  1292 
  1293 * Improved infrastructure for term evaluation using code generator
  1294 techniques, in particular static evaluation conversions.
  1295 
  1296 * Code generator: Scala (2.8 or higher) has been added to the target
  1297 languages.
  1298 
  1299 * Code generator: globbing constant expressions "*" and "Theory.*"
  1300 have been replaced by the more idiomatic "_" and "Theory._".
  1301 INCOMPATIBILITY.
  1302 
  1303 * Code generator: export_code without explicit file declaration prints
  1304 to standard output.  INCOMPATIBILITY.
  1305 
  1306 * Code generator: do not print function definitions for case
  1307 combinators any longer.
  1308 
  1309 * Code generator: simplification with rules determined with
  1310 src/Tools/Code/code_simp.ML and method "code_simp".
  1311 
  1312 * Code generator for records: more idiomatic representation of record
  1313 types.  Warning: records are not covered by ancient SML code
  1314 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1315 rep_datatype declaration helps to succeed then:
  1316 
  1317   record 'a foo = ...
  1318   ...
  1319   rep_datatype foo_ext ...
  1320 
  1321 * Records: logical foundation type for records does not carry a
  1322 '_type' suffix any longer (obsolete due to authentic syntax).
  1323 INCOMPATIBILITY.
  1324 
  1325 * Quickcheck now by default uses exhaustive testing instead of random
  1326 testing.  Random testing can be invoked by "quickcheck [random]",
  1327 exhaustive testing by "quickcheck [exhaustive]".
  1328 
  1329 * Quickcheck instantiates polymorphic types with small finite
  1330 datatypes by default. This enables a simple execution mechanism to
  1331 handle quantifiers and function equality over the finite datatypes.
  1332 
  1333 * Quickcheck random generator has been renamed from "code" to
  1334 "random".  INCOMPATIBILITY.
  1335 
  1336 * Quickcheck now has a configurable time limit which is set to 30
  1337 seconds by default. This can be changed by adding [timeout = n] to the
  1338 quickcheck command. The time limit for Auto Quickcheck is still set
  1339 independently.
  1340 
  1341 * Quickcheck in locales considers interpretations of that locale for
  1342 counter example search.
  1343 
  1344 * Sledgehammer:
  1345   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1346     method. See the Sledgehammer manual for details ("isabelle doc
  1347     sledgehammer").
  1348   - Renamed commands:
  1349     sledgehammer atp_info ~> sledgehammer running_provers
  1350     sledgehammer atp_kill ~> sledgehammer kill_provers
  1351     sledgehammer available_atps ~> sledgehammer available_provers
  1352     INCOMPATIBILITY.
  1353   - Renamed options:
  1354     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1355     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1356     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1357     (and "ms" and "min" are no longer supported)
  1358     INCOMPATIBILITY.
  1359 
  1360 * Nitpick:
  1361   - Renamed options:
  1362     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1363     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1364     INCOMPATIBILITY.
  1365   - Added support for partial quotient types.
  1366   - Added local versions of the "Nitpick.register_xxx" functions.
  1367   - Added "whack" option.
  1368   - Allow registration of quotient types as codatatypes.
  1369   - Improved "merge_type_vars" option to merge more types.
  1370   - Removed unsound "fast_descrs" option.
  1371   - Added custom symmetry breaking for datatypes, making it possible to reach
  1372     higher cardinalities.
  1373   - Prevent the expansion of too large definitions.
  1374 
  1375 * Proof methods "metis" and "meson" now have configuration options
  1376 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1377 to diagnose these tools. E.g.
  1378 
  1379     using [[metis_trace = true]]
  1380 
  1381 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1382 manually as command 'solve_direct'.
  1383 
  1384 * The default SMT solver Z3 must be enabled explicitly (due to
  1385 licensing issues) by setting the environment variable
  1386 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1387 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1388 changing the SMT solver is done via the configuration option
  1389 "smt_solver".
  1390 
  1391 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1392 i.e. "remote_cvc3" and "remote_z3".
  1393 
  1394 * Added basic SMT support for datatypes, records, and typedefs using
  1395 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1396 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1397 support for a similar behavior).  Minor INCOMPATIBILITY.
  1398 
  1399 * Changed SMT configuration options:
  1400   - Renamed:
  1401     z3_proofs ~> smt_oracle (with inverted meaning)
  1402     z3_trace_assms ~> smt_trace_used_facts
  1403     INCOMPATIBILITY.
  1404   - Added:
  1405     smt_verbose
  1406     smt_random_seed
  1407     smt_datatypes
  1408     smt_infer_triggers
  1409     smt_monomorph_limit
  1410     cvc3_options
  1411     remote_cvc3_options
  1412     remote_z3_options
  1413     yices_options
  1414 
  1415 * Boogie output files (.b2i files) need to be declared in the theory
  1416 header.
  1417 
  1418 * Simplification procedure "list_to_set_comprehension" rewrites list
  1419 comprehensions applied to List.set to set comprehensions.  Occasional
  1420 INCOMPATIBILITY, may be deactivated like this:
  1421 
  1422   declare [[simproc del: list_to_set_comprehension]]
  1423 
  1424 * Removed old version of primrec package.  INCOMPATIBILITY.
  1425 
  1426 * Removed simplifier congruence rule of "prod_case", as has for long
  1427 been the case with "split".  INCOMPATIBILITY.
  1428 
  1429 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  1430 
  1431 * Removed [split_format ... and ... and ...] version of
  1432 [split_format].  Potential INCOMPATIBILITY.
  1433 
  1434 * Predicate "sorted" now defined inductively, with nice induction
  1435 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  1436 
  1437 * Constant "contents" renamed to "the_elem", to free the generic name
  1438 contents for other uses.  INCOMPATIBILITY.
  1439 
  1440 * Renamed class eq and constant eq (for code generation) to class
  1441 equal and constant equal, plus renaming of related facts and various
  1442 tuning.  INCOMPATIBILITY.
  1443 
  1444 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  1445 
  1446 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  1447 INCOMPATIBILITY.
  1448 
  1449 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  1450 avoid confusion with finite sets.  INCOMPATIBILITY.
  1451 
  1452 * Abandoned locales equiv, congruent and congruent2 for equivalence
  1453 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  1454 for congruent(2)).
  1455 
  1456 * Some previously unqualified names have been qualified:
  1457 
  1458   types
  1459     bool ~> HOL.bool
  1460     nat ~> Nat.nat
  1461 
  1462   constants
  1463     Trueprop ~> HOL.Trueprop
  1464     True ~> HOL.True
  1465     False ~> HOL.False
  1466     op & ~> HOL.conj
  1467     op | ~> HOL.disj
  1468     op --> ~> HOL.implies
  1469     op = ~> HOL.eq
  1470     Not ~> HOL.Not
  1471     The ~> HOL.The
  1472     All ~> HOL.All
  1473     Ex ~> HOL.Ex
  1474     Ex1 ~> HOL.Ex1
  1475     Let ~> HOL.Let
  1476     If ~> HOL.If
  1477     Ball ~> Set.Ball
  1478     Bex ~> Set.Bex
  1479     Suc ~> Nat.Suc
  1480     Pair ~> Product_Type.Pair
  1481     fst ~> Product_Type.fst
  1482     snd ~> Product_Type.snd
  1483     curry ~> Product_Type.curry
  1484     op : ~> Set.member
  1485     Collect ~> Set.Collect
  1486 
  1487 INCOMPATIBILITY.
  1488 
  1489 * More canonical naming convention for some fundamental definitions:
  1490 
  1491     bot_bool_eq ~> bot_bool_def
  1492     top_bool_eq ~> top_bool_def
  1493     inf_bool_eq ~> inf_bool_def
  1494     sup_bool_eq ~> sup_bool_def
  1495     bot_fun_eq  ~> bot_fun_def
  1496     top_fun_eq  ~> top_fun_def
  1497     inf_fun_eq  ~> inf_fun_def
  1498     sup_fun_eq  ~> sup_fun_def
  1499 
  1500 INCOMPATIBILITY.
  1501 
  1502 * More stylized fact names:
  1503 
  1504   expand_fun_eq ~> fun_eq_iff
  1505   expand_set_eq ~> set_eq_iff
  1506   set_ext       ~> set_eqI
  1507   nat_number    ~> eval_nat_numeral
  1508 
  1509 INCOMPATIBILITY.
  1510 
  1511 * Refactoring of code-generation specific operations in theory List:
  1512 
  1513   constants
  1514     null ~> List.null
  1515 
  1516   facts
  1517     mem_iff ~> member_def
  1518     null_empty ~> null_def
  1519 
  1520 INCOMPATIBILITY.  Note that these were not supposed to be used
  1521 regularly unless for striking reasons; their main purpose was code
  1522 generation.
  1523 
  1524 Various operations from the Haskell prelude are used for generating
  1525 Haskell code.
  1526 
  1527 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  1528 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  1529 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  1530 
  1531 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  1532 "*" and "+" respectively.  INCOMPATIBILITY.
  1533 
  1534 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  1535 "Sum_Type.Plus" instead.
  1536 
  1537 * Constant "split" has been merged with constant "prod_case"; names of
  1538 ML functions, facts etc. involving split have been retained so far,
  1539 though.  INCOMPATIBILITY.
  1540 
  1541 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  1542 instead.  INCOMPATIBILITY.
  1543 
  1544 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  1545 INCOMPATIBILITY.
  1546 
  1547 * Former theory Library/Enum is now part of the HOL-Main image.
  1548 INCOMPATIBILITY: all constants of the Enum theory now have to be
  1549 referred to by its qualified name.
  1550 
  1551   enum    ~>  Enum.enum
  1552   nlists  ~>  Enum.nlists
  1553   product ~>  Enum.product
  1554 
  1555 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  1556 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  1557 INCOMPATIBILITY.
  1558 
  1559 * Theory Library/SetsAndFunctions has been split into
  1560 Library/Function_Algebras and Library/Set_Algebras; canonical names
  1561 for instance definitions for functions; various improvements.
  1562 INCOMPATIBILITY.
  1563 
  1564 * Theory Library/Multiset provides stable quicksort implementation of
  1565 sort_key.
  1566 
  1567 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  1568 INCOMPATIBILITY.
  1569 
  1570 * Session Multivariate_Analysis: introduced a type class for euclidean
  1571 space.  Most theorems are now stated in terms of euclidean spaces
  1572 instead of finite cartesian products.
  1573 
  1574   types
  1575     real ^ 'n ~>  'a::real_vector
  1576               ~>  'a::euclidean_space
  1577               ~>  'a::ordered_euclidean_space
  1578         (depends on your needs)
  1579 
  1580   constants
  1581      _ $ _        ~> _ $$ _
  1582      \<chi> x. _  ~> \<chi>\<chi> x. _
  1583      CARD('n)     ~> DIM('a)
  1584 
  1585 Also note that the indices are now natural numbers and not from some
  1586 finite type. Finite cartesian products of euclidean spaces, products
  1587 of euclidean spaces the real and complex numbers are instantiated to
  1588 be euclidean_spaces.  INCOMPATIBILITY.
  1589 
  1590 * Session Probability: introduced pextreal as positive extended real
  1591 numbers.  Use pextreal as value for measures.  Introduce the
  1592 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  1593 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  1594 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  1595 
  1596 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  1597 INCOMPATIBILITY.
  1598 
  1599 * Session SPARK (with image HOL-SPARK) provides commands to load and
  1600 prove verification conditions generated by the SPARK Ada program
  1601 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  1602 
  1603 
  1604 *** HOL-Algebra ***
  1605 
  1606 * Theorems for additive ring operations (locale abelian_monoid and
  1607 descendants) are generated by interpretation from their multiplicative
  1608 counterparts.  Names (in particular theorem names) have the mandatory
  1609 qualifier 'add'.  Previous theorem names are redeclared for
  1610 compatibility.
  1611 
  1612 * Structure "int_ring" is now an abbreviation (previously a
  1613 definition).  This fits more natural with advanced interpretations.
  1614 
  1615 
  1616 *** HOLCF ***
  1617 
  1618 * The domain package now runs in definitional mode by default: The
  1619 former command 'new_domain' is now called 'domain'.  To use the domain
  1620 package in its original axiomatic mode, use 'domain (unsafe)'.
  1621 INCOMPATIBILITY.
  1622 
  1623 * The new class "domain" is now the default sort.  Class "predomain"
  1624 is an unpointed version of "domain". Theories can be updated by
  1625 replacing sort annotations as shown below.  INCOMPATIBILITY.
  1626 
  1627   'a::type ~> 'a::countable
  1628   'a::cpo  ~> 'a::predomain
  1629   'a::pcpo ~> 'a::domain
  1630 
  1631 * The old type class "rep" has been superseded by class "domain".
  1632 Accordingly, users of the definitional package must remove any
  1633 "default_sort rep" declarations.  INCOMPATIBILITY.
  1634 
  1635 * The domain package (definitional mode) now supports unpointed
  1636 predomain argument types, as long as they are marked 'lazy'. (Strict
  1637 arguments must be in class "domain".) For example, the following
  1638 domain definition now works:
  1639 
  1640   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  1641 
  1642 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  1643 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  1644 'a option, and 'a list.  Additionally, it configures fixrec and the
  1645 domain package to work with these types.  For example:
  1646 
  1647   fixrec isInl :: "('a + 'b) u -> tr"
  1648     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  1649 
  1650   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  1651 
  1652 * The "(permissive)" option of fixrec has been replaced with a
  1653 per-equation "(unchecked)" option. See
  1654 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  1655 
  1656 * The "bifinite" class no longer fixes a constant "approx"; the class
  1657 now just asserts that such a function exists.  INCOMPATIBILITY.
  1658 
  1659 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  1660 defines an embedding of type 'a defl into udom by default; instances
  1661 of "bifinite" and "domain" classes are available in
  1662 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  1663 
  1664 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  1665 
  1666 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  1667 
  1668 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  1669 
  1670 * The function "cprod_map" has been renamed to "prod_map".
  1671 INCOMPATIBILITY.
  1672 
  1673 * The monadic bind operator on each powerdomain has new binder syntax
  1674 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  1675 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  1676 
  1677 * The infix syntax for binary union on each powerdomain has changed
  1678 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  1679 syntax.  INCOMPATIBILITY.
  1680 
  1681 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  1682 still supported as an input translation.
  1683 
  1684 * Renamed some theorems (the original names are also still available).
  1685 
  1686   expand_fun_below   ~> fun_below_iff
  1687   below_fun_ext      ~> fun_belowI
  1688   expand_cfun_eq     ~> cfun_eq_iff
  1689   ext_cfun           ~> cfun_eqI
  1690   expand_cfun_below  ~> cfun_below_iff
  1691   below_cfun_ext     ~> cfun_belowI
  1692   cont2cont_Rep_CFun ~> cont2cont_APP
  1693 
  1694 * The Abs and Rep functions for various types have changed names.
  1695 Related theorem names have also changed to match. INCOMPATIBILITY.
  1696 
  1697   Rep_CFun  ~> Rep_cfun
  1698   Abs_CFun  ~> Abs_cfun
  1699   Rep_Sprod ~> Rep_sprod
  1700   Abs_Sprod ~> Abs_sprod
  1701   Rep_Ssum  ~> Rep_ssum
  1702   Abs_Ssum  ~> Abs_ssum
  1703 
  1704 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  1705 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  1706 
  1707 * Various changes to bisimulation/coinduction with domain package:
  1708 
  1709   - Definitions of "bisim" constants no longer mention definedness.
  1710   - With mutual recursion, "bisim" predicate is now curried.
  1711   - With mutual recursion, each type gets a separate coind theorem.
  1712   - Variable names in bisim_def and coinduct rules have changed.
  1713 
  1714 INCOMPATIBILITY.
  1715 
  1716 * Case combinators generated by the domain package for type "foo" are
  1717 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  1718 
  1719 * Several theorems have been renamed to more accurately reflect the
  1720 names of constants and types involved.  INCOMPATIBILITY.
  1721 
  1722   thelub_const    ~> lub_const
  1723   lub_const       ~> is_lub_const
  1724   thelubI         ~> lub_eqI
  1725   is_lub_lub      ~> is_lubD2
  1726   lubI            ~> is_lub_lub
  1727   unique_lub      ~> is_lub_unique
  1728   is_ub_lub       ~> is_lub_rangeD1
  1729   lub_bin_chain   ~> is_lub_bin_chain
  1730   lub_fun         ~> is_lub_fun
  1731   thelub_fun      ~> lub_fun
  1732   thelub_cfun     ~> lub_cfun
  1733   thelub_Pair     ~> lub_Pair
  1734   lub_cprod       ~> is_lub_prod
  1735   thelub_cprod    ~> lub_prod
  1736   minimal_cprod   ~> minimal_prod
  1737   inst_cprod_pcpo ~> inst_prod_pcpo
  1738   UU_I            ~> bottomI
  1739   compact_UU      ~> compact_bottom
  1740   deflation_UU    ~> deflation_bottom
  1741   finite_deflation_UU ~> finite_deflation_bottom
  1742 
  1743 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  1744 
  1745   sq_ord_less_eq_trans ~> below_eq_trans
  1746   sq_ord_eq_less_trans ~> eq_below_trans
  1747   refl_less            ~> below_refl
  1748   trans_less           ~> below_trans
  1749   antisym_less         ~> below_antisym
  1750   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  1751   box_less             ~> box_below
  1752   rev_trans_less       ~> rev_below_trans
  1753   not_less2not_eq      ~> not_below2not_eq
  1754   less_UU_iff          ~> below_UU_iff
  1755   flat_less_iff        ~> flat_below_iff
  1756   adm_less             ~> adm_below
  1757   adm_not_less         ~> adm_not_below
  1758   adm_compact_not_less ~> adm_compact_not_below
  1759   less_fun_def         ~> below_fun_def
  1760   expand_fun_less      ~> fun_below_iff
  1761   less_fun_ext         ~> fun_belowI
  1762   less_discr_def       ~> below_discr_def
  1763   discr_less_eq        ~> discr_below_eq
  1764   less_unit_def        ~> below_unit_def
  1765   less_cprod_def       ~> below_prod_def
  1766   prod_lessI           ~> prod_belowI
  1767   Pair_less_iff        ~> Pair_below_iff
  1768   fst_less_iff         ~> fst_below_iff
  1769   snd_less_iff         ~> snd_below_iff
  1770   expand_cfun_less     ~> cfun_below_iff
  1771   less_cfun_ext        ~> cfun_belowI
  1772   injection_less       ~> injection_below
  1773   less_up_def          ~> below_up_def
  1774   not_Iup_less         ~> not_Iup_below
  1775   Iup_less             ~> Iup_below
  1776   up_less              ~> up_below
  1777   Def_inject_less_eq   ~> Def_below_Def
  1778   Def_less_is_eq       ~> Def_below_iff
  1779   spair_less_iff       ~> spair_below_iff
  1780   less_sprod           ~> below_sprod
  1781   spair_less           ~> spair_below
  1782   sfst_less_iff        ~> sfst_below_iff
  1783   ssnd_less_iff        ~> ssnd_below_iff
  1784   fix_least_less       ~> fix_least_below
  1785   dist_less_one        ~> dist_below_one
  1786   less_ONE             ~> below_ONE
  1787   ONE_less_iff         ~> ONE_below_iff
  1788   less_sinlD           ~> below_sinlD
  1789   less_sinrD           ~> below_sinrD
  1790 
  1791 
  1792 *** FOL and ZF ***
  1793 
  1794 * All constant names are now qualified internally and use proper
  1795 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  1796 
  1797 *** ZF ***
  1798 
  1799 * Greater support for structured proofs involving induction or case analysis.
  1800 
  1801 * Much greater use of special symbols.
  1802 
  1803 * Removal of many ML theorem bindings. INCOMPATIBILITY.
  1804 
  1805 *** ML ***
  1806 
  1807 * Antiquotation @{assert} inlines a function bool -> unit that raises
  1808 Fail if the argument is false.  Due to inlining the source position of
  1809 failed assertions is included in the error output.
  1810 
  1811 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  1812 text is in practice always evaluated with a stable theory checkpoint.
  1813 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  1814 
  1815 * Antiquotation @{theory A} refers to theory A from the ancestry of
  1816 the current context, not any accidental theory loader state as before.
  1817 Potential INCOMPATIBILITY, subtle change in semantics.
  1818 
  1819 * Syntax.pretty_priority (default 0) configures the required priority
  1820 of pretty-printed output and thus affects insertion of parentheses.
  1821 
  1822 * Syntax.default_root (default "any") configures the inner syntax
  1823 category (nonterminal symbol) for parsing of terms.
  1824 
  1825 * Former exception Library.UnequalLengths now coincides with
  1826 ListPair.UnequalLengths.
  1827 
  1828 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1829 main functionality is provided by structure Simplifier.
  1830 
  1831 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1832 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1833 almost all situations.
  1834 
  1835 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1836 See implementation manual for further details on exceptions in
  1837 Isabelle/ML.
  1838 
  1839 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1840 meaning.
  1841 
  1842 * Renamed structure PureThy to Pure_Thy and moved most of its
  1843 operations to structure Global_Theory, to emphasize that this is
  1844 rarely-used global-only stuff.
  1845 
  1846 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1847 instead (or tracing for high-volume output).
  1848 
  1849 * Configuration option show_question_marks only affects regular pretty
  1850 printing of types and terms, not raw Term.string_of_vname.
  1851 
  1852 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1853 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1854 @{thms} for most purposes.
  1855 
  1856 * ML structure Unsynchronized is never opened, not even in Isar
  1857 interaction mode as before.  Old Unsynchronized.set etc. have been
  1858 discontinued -- use plain := instead.  This should be *rare* anyway,
  1859 since modern tools always work via official context data, notably
  1860 configuration options.
  1861 
  1862 * Parallel and asynchronous execution requires special care concerning
  1863 interrupts.  Structure Exn provides some convenience functions that
  1864 avoid working directly with raw Interrupt.  User code must not absorb
  1865 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1866 followed by re-raising of the original exception.  Another common
  1867 source of mistakes are "handle _" patterns, which make the meaning of
  1868 the program subject to physical effects of the environment.
  1869 
  1870 
  1871 
  1872 New in Isabelle2009-2 (June 2010)
  1873 ---------------------------------
  1874 
  1875 *** General ***
  1876 
  1877 * Authentic syntax for *all* logical entities (type classes, type
  1878 constructors, term constants): provides simple and robust
  1879 correspondence between formal entities and concrete syntax.  Within
  1880 the parse tree / AST representations, "constants" are decorated by
  1881 their category (class, type, const) and spelled out explicitly with
  1882 their full internal name.
  1883 
  1884 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1885 and translations (translation rules and translation functions in ML).
  1886 Some hints on upgrading:
  1887 
  1888   - Many existing uses of 'syntax' and 'translations' can be replaced
  1889     by more modern 'type_notation', 'notation' and 'abbreviation',
  1890     which are independent of this issue.
  1891 
  1892   - 'translations' require markup within the AST; the term syntax
  1893     provides the following special forms:
  1894 
  1895       CONST c   -- produces syntax version of constant c from context
  1896       XCONST c  -- literally c, checked as constant from context
  1897       c         -- literally c, if declared by 'syntax'
  1898 
  1899     Plain identifiers are treated as AST variables -- occasionally the
  1900     system indicates accidental variables via the error "rhs contains
  1901     extra variables".
  1902 
  1903     Type classes and type constructors are marked according to their
  1904     concrete syntax.  Some old translations rules need to be written
  1905     for the "type" category, using type constructor application
  1906     instead of pseudo-term application of the default category
  1907     "logic".
  1908 
  1909   - 'parse_translation' etc. in ML may use the following
  1910     antiquotations:
  1911 
  1912       @{class_syntax c}   -- type class c within parse tree / AST
  1913       @{term_syntax c}    -- type constructor c within parse tree / AST
  1914       @{const_syntax c}   -- ML version of "CONST c" above
  1915       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1916 
  1917   - Literal types within 'typed_print_translations', i.e. those *not*
  1918     represented as pseudo-terms are represented verbatim.  Use @{class
  1919     c} or @{type_name c} here instead of the above syntax
  1920     antiquotations.
  1921 
  1922 Note that old non-authentic syntax was based on unqualified base
  1923 names, so all of the above "constant" names would coincide.  Recall
  1924 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1925 diagnose syntax problems.
  1926 
  1927 * Type constructors admit general mixfix syntax, not just infix.
  1928 
  1929 * Concrete syntax may be attached to local entities without a proof
  1930 body, too.  This works via regular mixfix annotations for 'fix',
  1931 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1932 similar to the 'notation' command in theory specifications.
  1933 
  1934 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1935 need to specify constant name and syntax separately.  Internal ML
  1936 datatype constructors have been renamed from InfixName to Infix etc.
  1937 Minor INCOMPATIBILITY.
  1938 
  1939 * Schematic theorem statements need to be explicitly markup as such,
  1940 via commands 'schematic_lemma', 'schematic_theorem',
  1941 'schematic_corollary'.  Thus the relevance of the proof is made
  1942 syntactically clear, which impacts performance in a parallel or
  1943 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1944 
  1945 * Use of cumulative prems via "!" in some proof methods has been
  1946 discontinued (old legacy feature).
  1947 
  1948 * References 'trace_simp' and 'debug_simp' have been replaced by
  1949 configuration options stored in the context. Enabling tracing (the
  1950 case of debugging is similar) in proofs works via
  1951 
  1952   using [[trace_simp = true]]
  1953 
  1954 Tracing is then active for all invocations of the simplifier in
  1955 subsequent goal refinement steps. Tracing may also still be enabled or
  1956 disabled via the ProofGeneral settings menu.
  1957 
  1958 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1959 'hide_fact' replace the former 'hide' KIND command.  Minor
  1960 INCOMPATIBILITY.
  1961 
  1962 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1963 more efficient than combinations with -q1 or -q2.
  1964 
  1965 
  1966 *** Pure ***
  1967 
  1968 * Proofterms record type-class reasoning explicitly, using the
  1969 "unconstrain" operation internally.  This eliminates all sort
  1970 constraints from a theorem and proof, introducing explicit
  1971 OFCLASS-premises.  On the proof term level, this operation is
  1972 automatically applied at theorem boundaries, such that closed proofs
  1973 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1974 inspect proof terms.
  1975 
  1976 * Local theory specifications may depend on extra type variables that
  1977 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1978 are added internally.  For example:
  1979 
  1980   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1981 
  1982 * Predicates of locales introduced by classes carry a mandatory
  1983 "class" prefix.  INCOMPATIBILITY.
  1984 
  1985 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1986 
  1987 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1988 'class' instead.
  1989 
  1990 * Command 'code_reflect' allows to incorporate generated ML code into
  1991 runtime environment; replaces immature code_datatype antiquotation.
  1992 INCOMPATIBILITY.
  1993 
  1994 * Code generator: simple concept for abstract datatypes obeying
  1995 invariants.
  1996 
  1997 * Code generator: details of internal data cache have no impact on the
  1998 user space functionality any longer.
  1999 
  2000 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  2001 subgoals.  This is more appropriate for interpretations with 'where'.
  2002 INCOMPATIBILITY.
  2003 
  2004 * Command 'example_proof' opens an empty proof body.  This allows to
  2005 experiment with Isar, without producing any persistent result.
  2006 
  2007 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  2008 within a local theory context, with explicit checking of the
  2009 constructors involved (in contrast to the raw 'syntax' versions).
  2010 
  2011 * Commands 'types' and 'typedecl' now work within a local theory
  2012 context -- without introducing dependencies on parameters or
  2013 assumptions, which is not possible in Isabelle/Pure.
  2014 
  2015 * Command 'defaultsort' has been renamed to 'default_sort', it works
  2016 within a local theory context.  Minor INCOMPATIBILITY.
  2017 
  2018 
  2019 *** HOL ***
  2020 
  2021 * Command 'typedef' now works within a local theory context -- without
  2022 introducing dependencies on parameters or assumptions, which is not
  2023 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  2024 contain multiple interpretations of local typedefs (with different
  2025 non-emptiness proofs), even in a global theory context.
  2026 
  2027 * New package for quotient types.  Commands 'quotient_type' and
  2028 'quotient_definition' may be used for defining types and constants by
  2029 quotient constructions.  An example is the type of integers created by
  2030 quotienting pairs of natural numbers:
  2031 
  2032   fun
  2033     intrel :: "(nat * nat) => (nat * nat) => bool"
  2034   where
  2035     "intrel (x, y) (u, v) = (x + v = u + y)"
  2036 
  2037   quotient_type int = "nat * nat" / intrel
  2038     by (auto simp add: equivp_def expand_fun_eq)
  2039 
  2040   quotient_definition
  2041     "0::int" is "(0::nat, 0::nat)"
  2042 
  2043 The method "lifting" can be used to lift of theorems from the
  2044 underlying "raw" type to the quotient type.  The example
  2045 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  2046 construction and provides a reasoning infrastructure for finite sets.
  2047 
  2048 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  2049 clash with new theory Quotient in Main HOL.
  2050 
  2051 * Moved the SMT binding into the main HOL session, eliminating
  2052 separate HOL-SMT session.
  2053 
  2054 * List membership infix mem operation is only an input abbreviation.
  2055 INCOMPATIBILITY.
  2056 
  2057 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  2058 for future developements; former Library/Word.thy is still present in
  2059 the AFP entry RSAPPS.
  2060 
  2061 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  2062 longer shadowed.  INCOMPATIBILITY.
  2063 
  2064 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  2065 INCOMPATIBILITY.
  2066 
  2067 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  2068 INCOMPATIBILITY.
  2069 
  2070 * Dropped normalizing_semiring etc; use the facts in semiring classes
  2071 instead.  INCOMPATIBILITY.
  2072 
  2073 * Dropped several real-specific versions of lemmas about floor and
  2074 ceiling; use the generic lemmas from theory "Archimedean_Field"
  2075 instead.  INCOMPATIBILITY.
  2076 
  2077   floor_number_of_eq         ~> floor_number_of
  2078   le_floor_eq_number_of      ~> number_of_le_floor
  2079   le_floor_eq_zero           ~> zero_le_floor
  2080   le_floor_eq_one            ~> one_le_floor
  2081   floor_less_eq_number_of    ~> floor_less_number_of
  2082   floor_less_eq_zero         ~> floor_less_zero
  2083   floor_less_eq_one          ~> floor_less_one
  2084   less_floor_eq_number_of    ~> number_of_less_floor
  2085   less_floor_eq_zero         ~> zero_less_floor
  2086   less_floor_eq_one          ~> one_less_floor
  2087   floor_le_eq_number_of      ~> floor_le_number_of
  2088   floor_le_eq_zero           ~> floor_le_zero
  2089   floor_le_eq_one            ~> floor_le_one
  2090   floor_subtract_number_of   ~> floor_diff_number_of
  2091   floor_subtract_one         ~> floor_diff_one
  2092   ceiling_number_of_eq       ~> ceiling_number_of
  2093   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  2094   ceiling_le_zero_eq         ~> ceiling_le_zero
  2095   ceiling_le_eq_one          ~> ceiling_le_one
  2096   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  2097   less_ceiling_eq_zero       ~> zero_less_ceiling
  2098   less_ceiling_eq_one        ~> one_less_ceiling
  2099   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  2100   ceiling_less_eq_zero       ~> ceiling_less_zero
  2101   ceiling_less_eq_one        ~> ceiling_less_one
  2102   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  2103   le_ceiling_eq_zero         ~> zero_le_ceiling
  2104   le_ceiling_eq_one          ~> one_le_ceiling
  2105   ceiling_subtract_number_of ~> ceiling_diff_number_of
  2106   ceiling_subtract_one       ~> ceiling_diff_one
  2107 
  2108 * Theory "Finite_Set": various folding_XXX locales facilitate the
  2109 application of the various fold combinators on finite sets.
  2110 
  2111 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  2112 provides abstract red-black tree type which is backed by "RBT_Impl" as
  2113 implementation.  INCOMPATIBILTY.
  2114 
  2115 * Theory Library/Coinductive_List has been removed -- superseded by
  2116 AFP/thys/Coinductive.
  2117 
  2118 * Theory PReal, including the type "preal" and related operations, has
  2119 been removed.  INCOMPATIBILITY.
  2120 
  2121 * Real: new development using Cauchy Sequences.
  2122 
  2123 * Split off theory "Big_Operators" containing setsum, setprod,
  2124 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  2125 
  2126 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  2127 "Int" etc.  INCOMPATIBILITY.
  2128 
  2129 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  2130 
  2131 * New set of rules "ac_simps" provides combined assoc / commute
  2132 rewrites for all interpretations of the appropriate generic locales.
  2133 
  2134 * Renamed theory "OrderedGroup" to "Groups" and split theory
  2135 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  2136 appropriate and more consistent names suitable for name prefixes
  2137 within the HOL theories.  INCOMPATIBILITY.
  2138 
  2139 * Some generic constants have been put to appropriate theories:
  2140   - less_eq, less: Orderings
  2141   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  2142   - inverse, divide: Rings
  2143 INCOMPATIBILITY.
  2144 
  2145 * More consistent naming of type classes involving orderings (and
  2146 lattices):
  2147 
  2148     lower_semilattice                   ~> semilattice_inf
  2149     upper_semilattice                   ~> semilattice_sup
  2150 
  2151     dense_linear_order                  ~> dense_linorder
  2152 
  2153     pordered_ab_group_add               ~> ordered_ab_group_add
  2154     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  2155     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  2156     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  2157     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  2158     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  2159     pordered_cancel_semiring            ~> ordered_cancel_semiring
  2160     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  2161     pordered_comm_ring                  ~> ordered_comm_ring
  2162     pordered_comm_semiring              ~> ordered_comm_semiring
  2163     pordered_ring                       ~> ordered_ring
  2164     pordered_ring_abs                   ~> ordered_ring_abs
  2165     pordered_semiring                   ~> ordered_semiring
  2166 
  2167     ordered_ab_group_add                ~> linordered_ab_group_add
  2168     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  2169     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  2170     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  2171     ordered_field                       ~> linordered_field
  2172     ordered_field_no_lb                 ~> linordered_field_no_lb
  2173     ordered_field_no_ub                 ~> linordered_field_no_ub
  2174     ordered_field_dense_linear_order    ~> dense_linordered_field
  2175     ordered_idom                        ~> linordered_idom
  2176     ordered_ring                        ~> linordered_ring
  2177     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  2178     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  2179     ordered_ring_strict                 ~> linordered_ring_strict
  2180     ordered_semidom                     ~> linordered_semidom
  2181     ordered_semiring                    ~> linordered_semiring
  2182     ordered_semiring_1                  ~> linordered_semiring_1
  2183     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  2184     ordered_semiring_strict             ~> linordered_semiring_strict
  2185 
  2186   The following slightly odd type classes have been moved to a
  2187   separate theory Library/Lattice_Algebras:
  2188 
  2189     lordered_ab_group_add               ~> lattice_ab_group_add
  2190     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  2191     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  2192     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  2193     lordered_ring                       ~> lattice_ring
  2194 
  2195 INCOMPATIBILITY.
  2196 
  2197 * Refined field classes:
  2198   - classes division_ring_inverse_zero, field_inverse_zero,
  2199     linordered_field_inverse_zero include rule inverse 0 = 0 --
  2200     subsumes former division_by_zero class;
  2201   - numerous lemmas have been ported from field to division_ring.
  2202 INCOMPATIBILITY.
  2203 
  2204 * Refined algebra theorem collections:
  2205   - dropped theorem group group_simps, use algebra_simps instead;
  2206   - dropped theorem group ring_simps, use field_simps instead;
  2207   - proper theorem collection field_simps subsumes former theorem
  2208     groups field_eq_simps and field_simps;
  2209   - dropped lemma eq_minus_self_iff which is a duplicate for
  2210     equal_neg_zero.
  2211 INCOMPATIBILITY.
  2212 
  2213 * Theory Finite_Set and List: some lemmas have been generalized from
  2214 sets to lattices:
  2215 
  2216   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  2217   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  2218   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  2219   union_Union_fold_union        ~> sup_Sup_fold_sup
  2220   Inter_fold_inter              ~> Inf_fold_inf
  2221   Union_fold_union              ~> Sup_fold_sup
  2222   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  2223   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  2224   INTER_fold_inter              ~> INFI_fold_inf
  2225   UNION_fold_union              ~> SUPR_fold_sup
  2226 
  2227 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  2228 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  2229 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  2230 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  2231 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  2232 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  2233 
  2234 * Reorganized theory Multiset: swapped notation of pointwise and
  2235 multiset order:
  2236 
  2237   - pointwise ordering is instance of class order with standard syntax
  2238     <= and <;
  2239   - multiset ordering has syntax <=# and <#; partial order properties
  2240     are provided by means of interpretation with prefix
  2241     multiset_order;
  2242   - less duplication, less historical organization of sections,
  2243     conversion from associations lists to multisets, rudimentary code
  2244     generation;
  2245   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  2246     if needed.
  2247 
  2248 Renamed:
  2249 
  2250   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  2251   multi_count_ext  ~>  multiset_ext
  2252   diff_union_inverse2  ~>  diff_union_cancelR
  2253 
  2254 INCOMPATIBILITY.
  2255 
  2256 * Theory Permutation: replaced local "remove" by List.remove1.
  2257 
  2258 * Code generation: ML and OCaml code is decorated with signatures.
  2259 
  2260 * Theory List: added transpose.
  2261 
  2262 * Library/Nat_Bijection.thy is a collection of bijective functions
  2263 between nat and other types, which supersedes the older libraries
  2264 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  2265 
  2266   Constants:
  2267   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  2268   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  2269   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  2270   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  2271   Countable.pair_encode           ~> prod_encode
  2272   NatIso.prod2nat                 ~> prod_encode
  2273   NatIso.nat2prod                 ~> prod_decode
  2274   NatIso.sum2nat                  ~> sum_encode
  2275   NatIso.nat2sum                  ~> sum_decode
  2276   NatIso.list2nat                 ~> list_encode
  2277   NatIso.nat2list                 ~> list_decode
  2278   NatIso.set2nat                  ~> set_encode
  2279   NatIso.nat2set                  ~> set_decode
  2280 
  2281   Lemmas:
  2282   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2283   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2284   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2285   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2286   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2287   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2288   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2289   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2290   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2291   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2292   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2293   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2294   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2295 
  2296 * Sledgehammer:
  2297   - Renamed ATP commands:
  2298     atp_info     ~> sledgehammer running_atps
  2299     atp_kill     ~> sledgehammer kill_atps
  2300     atp_messages ~> sledgehammer messages
  2301     atp_minimize ~> sledgehammer minimize
  2302     print_atps   ~> sledgehammer available_atps
  2303     INCOMPATIBILITY.
  2304   - Added user's manual ("isabelle doc sledgehammer").
  2305   - Added option syntax and "sledgehammer_params" to customize
  2306     Sledgehammer's behavior.  See the manual for details.
  2307   - Modified the Isar proof reconstruction code so that it produces
  2308     direct proofs rather than proofs by contradiction.  (This feature
  2309     is still experimental.)
  2310   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2311     full-typed mode.
  2312   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2313 
  2314 * Nitpick:
  2315   - Added and implemented "binary_ints" and "bits" options.
  2316   - Added "std" option and implemented support for nonstandard models.
  2317   - Added and implemented "finitize" option to improve the precision
  2318     of infinite datatypes based on a monotonicity analysis.
  2319   - Added support for quotient types.
  2320   - Added support for "specification" and "ax_specification"
  2321     constructs.
  2322   - Added support for local definitions (for "function" and
  2323     "termination" proofs).
  2324   - Added support for term postprocessors.
  2325   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2326   - Improved efficiency of "destroy_constrs" optimization.
  2327   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2328     record getters.
  2329   - Fixed soundness bug related to higher-order constructors.
  2330   - Fixed soundness bug when "full_descrs" is enabled.
  2331   - Improved precision of set constructs.
  2332   - Added "atoms" option.
  2333   - Added cache to speed up repeated Kodkod invocations on the same
  2334     problems.
  2335   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2336     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2337     "SAT4J_Light".  INCOMPATIBILITY.
  2338   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2339     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2340   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2341 
  2342 * Method "induct" now takes instantiations of the form t, where t is not
  2343   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2344   If this is not intended, t has to be enclosed in parentheses.
  2345   By default, the equalities generated by definitional instantiations
  2346   are pre-simplified, which may cause parameters of inductive cases
  2347   to disappear, or may even delete some of the inductive cases.
  2348   Use "induct (no_simp)" instead of "induct" to restore the old
  2349   behaviour. The (no_simp) option is also understood by the "cases"
  2350   and "nominal_induct" methods, which now perform pre-simplification, too.
  2351   INCOMPATIBILITY.
  2352 
  2353 
  2354 *** HOLCF ***
  2355 
  2356 * Variable names in lemmas generated by the domain package have
  2357 changed; the naming scheme is now consistent with the HOL datatype
  2358 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2359 
  2360 * The domain package no longer defines the function "foo_copy" for
  2361 recursive domain "foo".  The reach lemma is now stated directly in
  2362 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2363 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2364 
  2365 * Most definedness lemmas generated by the domain package (previously
  2366 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2367 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2368 Proofs that used definedness lemmas as intro rules may break,
  2369 potential INCOMPATIBILITY.
  2370 
  2371 * Induction and casedist rules generated by the domain package now
  2372 declare proper case_names (one called "bottom", and one named for each
  2373 constructor).  INCOMPATIBILITY.
  2374 
  2375 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2376 rules are generated for each domain, INCOMPATIBILITY.
  2377 
  2378   foo_bar.reach       ~> foo.reach  bar.reach
  2379   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2380 
  2381 * Some lemmas generated by the domain package have been renamed for
  2382 consistency with the datatype package, INCOMPATIBILITY.
  2383 
  2384   foo.ind        ~> foo.induct
  2385   foo.finite_ind ~> foo.finite_induct
  2386   foo.coind      ~> foo.coinduct
  2387   foo.casedist   ~> foo.exhaust
  2388   foo.exhaust    ~> foo.nchotomy
  2389 
  2390 * For consistency with other definition packages, the fixrec package
  2391 now generates qualified theorem names, INCOMPATIBILITY.
  2392 
  2393   foo_simps  ~> foo.simps
  2394   foo_unfold ~> foo.unfold
  2395   foo_induct ~> foo.induct
  2396 
  2397 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2398 method and internal fixrec proofs now use the default simpset instead.
  2399 INCOMPATIBILITY.
  2400 
  2401 * The "contlub" predicate has been removed.  Proof scripts should use
  2402 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2403 
  2404 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2405 
  2406 * The constants cpair, cfst, and csnd have been removed in favor of
  2407 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2408 
  2409 
  2410 *** ML ***
  2411 
  2412 * Antiquotations for basic formal entities:
  2413 
  2414     @{class NAME}         -- type class
  2415     @{class_syntax NAME}  -- syntax representation of the above
  2416 
  2417     @{type_name NAME}     -- logical type
  2418     @{type_abbrev NAME}   -- type abbreviation
  2419     @{nonterminal NAME}   -- type of concrete syntactic category
  2420     @{type_syntax NAME}   -- syntax representation of any of the above
  2421 
  2422     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2423     @{const_abbrev NAME}  -- abbreviated constant
  2424     @{const_syntax NAME}  -- syntax representation of any of the above
  2425 
  2426 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  2427 syntax constant (cf. 'syntax' command).
  2428 
  2429 * Antiquotation @{make_string} inlines a function to print arbitrary
  2430 values similar to the ML toplevel.  The result is compiler dependent
  2431 and may fall back on "?" in certain situations.
  2432 
  2433 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  2434 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  2435 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  2436 not work with the asynchronous Isar document model.
  2437 
  2438 * Configuration options now admit dynamic default values, depending on
  2439 the context or even global references.
  2440 
  2441 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  2442 uses an efficient external library if available (for Poly/ML).
  2443 
  2444 * Renamed some important ML structures, while keeping the old names
  2445 for some time as aliases within the structure Legacy:
  2446 
  2447   OuterKeyword  ~>  Keyword
  2448   OuterLex      ~>  Token
  2449   OuterParse    ~>  Parse
  2450   OuterSyntax   ~>  Outer_Syntax
  2451   PrintMode     ~>  Print_Mode
  2452   SpecParse     ~>  Parse_Spec
  2453   ThyInfo       ~>  Thy_Info
  2454   ThyLoad       ~>  Thy_Load
  2455   ThyOutput     ~>  Thy_Output
  2456   TypeInfer     ~>  Type_Infer
  2457 
  2458 Note that "open Legacy" simplifies porting of sources, but forgetting
  2459 to remove it again will complicate porting again in the future.
  2460 
  2461 * Most operations that refer to a global context are named
  2462 accordingly, e.g. Simplifier.global_context or
  2463 ProofContext.init_global.  There are some situations where a global
  2464 context actually works, but under normal circumstances one needs to
  2465 pass the proper local context through the code!
  2466 
  2467 * Discontinued old TheoryDataFun with its copy/init operation -- data
  2468 needs to be pure.  Functor Theory_Data_PP retains the traditional
  2469 Pretty.pp argument to merge, which is absent in the standard
  2470 Theory_Data version.
  2471 
  2472 * Sorts.certify_sort and derived "cert" operations for types and terms
  2473 no longer minimize sorts.  Thus certification at the boundary of the
  2474 inference kernel becomes invariant under addition of class relations,
  2475 which is an important monotonicity principle.  Sorts are now minimized
  2476 in the syntax layer only, at the boundary between the end-user and the
  2477 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  2478 explicitly in rare situations.
  2479 
  2480 * Renamed old-style Drule.standard to Drule.export_without_context, to
  2481 emphasize that this is in no way a standard operation.
  2482 INCOMPATIBILITY.
  2483 
  2484 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  2485 usual for resolution.  Rare INCOMPATIBILITY.
  2486 
  2487 * Renamed varify/unvarify operations to varify_global/unvarify_global
  2488 to emphasize that these only work in a global situation (which is
  2489 quite rare).
  2490 
  2491 * Curried take and drop in library.ML; negative length is interpreted
  2492 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  2493 
  2494 * Proof terms: type substitutions on proof constants now use canonical
  2495 order of type variables.  INCOMPATIBILITY for tools working with proof
  2496 terms.
  2497 
  2498 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  2499 may no longer carry premises.  User-level specifications are
  2500 transformed accordingly by Thm.add_axiom/add_def.
  2501 
  2502 
  2503 *** System ***
  2504 
  2505 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  2506 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  2507 proof terms are enabled unconditionally in the new HOL-Proofs image.
  2508 
  2509 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  2510 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  2511 respectively.
  2512 
  2513 * Old lib/scripts/polyml-platform is superseded by the
  2514 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  2515 variant, even on a 64 bit machine.  The following example setting
  2516 prefers 64 bit if available:
  2517 
  2518   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  2519 
  2520 * The preliminary Isabelle/jEdit application demonstrates the emerging
  2521 Isabelle/Scala layer for advanced prover interaction and integration.
  2522 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  2523 component.
  2524 
  2525 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  2526 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  2527 similar to the default assignment of the document preparation system
  2528 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  2529 provides some operations for direct access to the font without asking
  2530 the user for manual installation.
  2531 
  2532 
  2533 
  2534 New in Isabelle2009-1 (December 2009)
  2535 -------------------------------------
  2536 
  2537 *** General ***
  2538 
  2539 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  2540 one backslash should be used, even in ML sources.
  2541 
  2542 
  2543 *** Pure ***
  2544 
  2545 * Locale interpretation propagates mixins along the locale hierarchy.
  2546 The currently only available mixins are the equations used to map
  2547 local definitions to terms of the target domain of an interpretation.
  2548 
  2549 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  2550 loc" to print all interpretations of locale "loc" in the theory.
  2551 Interpretations in proofs are not shown.
  2552 
  2553 * Thoroughly revised locales tutorial.  New section on conditional
  2554 interpretation.
  2555 
  2556 * On instantiation of classes, remaining undefined class parameters
  2557 are formally declared.  INCOMPATIBILITY.
  2558 
  2559 
  2560 *** Document preparation ***
  2561 
  2562 * New generalized style concept for printing terms: @{foo (style) ...}
  2563 instead of @{foo_style style ...}  (old form is still retained for
  2564 backward compatibility).  Styles can be also applied for
  2565 antiquotations prop, term_type and typeof.
  2566 
  2567 
  2568 *** HOL ***
  2569 
  2570 * New proof method "smt" for a combination of first-order logic with
  2571 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  2572 fixed-size bitvectors; there is also basic support for higher-order
  2573 features (esp. lambda abstractions).  It is an incomplete decision
  2574 procedure based on external SMT solvers using the oracle mechanism;
  2575 for the SMT solver Z3, this method is proof-producing.  Certificates
  2576 are provided to avoid calling the external solvers solely for
  2577 re-checking proofs.  Due to a remote SMT service there is no need for
  2578 installing SMT solvers locally.  See src/HOL/SMT.
  2579 
  2580 * New commands to load and prove verification conditions generated by
  2581 the Boogie program verifier or derived systems (e.g. the Verifying C
  2582 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  2583 
  2584 * New counterexample generator tool 'nitpick' based on the Kodkod
  2585 relational model finder.  See src/HOL/Tools/Nitpick and
  2586 src/HOL/Nitpick_Examples.
  2587 
  2588 * New commands 'code_pred' and 'values' to invoke the predicate
  2589 compiler and to enumerate values of inductive predicates.
  2590 
  2591 * A tabled implementation of the reflexive transitive closure.
  2592 
  2593 * New implementation of quickcheck uses generic code generator;
  2594 default generators are provided for all suitable HOL types, records
  2595 and datatypes.  Old quickcheck can be re-activated importing theory
  2596 Library/SML_Quickcheck.
  2597 
  2598 * New testing tool Mirabelle for automated proof tools.  Applies
  2599 several tools and tactics like sledgehammer, metis, or quickcheck, to
  2600 every proof step in a theory.  To be used in batch mode via the
  2601 "mirabelle" utility.
  2602 
  2603 * New proof method "sos" (sum of squares) for nonlinear real
  2604 arithmetic (originally due to John Harison). It requires theory
  2605 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  2606 works well in practice on quantifier-free real arithmetic with +, -,
  2607 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  2608 inequalities between polynomials.  It makes use of external
  2609 semidefinite programming solvers.  Method "sos" generates a
  2610 certificate that can be pasted into the proof thus avoiding the need
  2611 to call an external tool every time the proof is checked.  See
  2612 src/HOL/Library/Sum_Of_Squares.
  2613 
  2614 * New method "linarith" invokes existing linear arithmetic decision
  2615 procedure only.
  2616 
  2617 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  2618 
  2619 * New Sledgehammer option "Full Types" in Proof General settings menu.
  2620 Causes full type information to be output to the ATPs.  This slows
  2621 ATPs down considerably but eliminates a source of unsound "proofs"
  2622 that fail later.
  2623 
  2624 * New method "metisFT": A version of metis that uses full type
  2625 information in order to avoid failures of proof reconstruction.
  2626 
  2627 * New evaluator "approximate" approximates an real valued term using
  2628 the same method as the approximation method.
  2629 
  2630 * Method "approximate" now supports arithmetic expressions as
  2631 boundaries of intervals and implements interval splitting and Taylor
  2632 series expansion.
  2633 
  2634 * ML antiquotation @{code_datatype} inserts definition of a datatype
  2635 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  2636 
  2637 * New theory SupInf of the supremum and infimum operators for sets of
  2638 reals.
  2639 
  2640 * New theory Probability, which contains a development of measure
  2641 theory, eventually leading to Lebesgue integration and probability.
  2642 
  2643 * Extended Multivariate Analysis to include derivation and Brouwer's
  2644 fixpoint theorem.
  2645 
  2646 * Reorganization of number theory, INCOMPATIBILITY:
  2647   - new number theory development for nat and int, in theories Divides
  2648     and GCD as well as in new session Number_Theory
  2649   - some constants and facts now suffixed with _nat and _int
  2650     accordingly
  2651   - former session NumberTheory now named Old_Number_Theory, including
  2652     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  2653   - moved theory Pocklington from src/HOL/Library to
  2654     src/HOL/Old_Number_Theory
  2655 
  2656 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  2657 lcm of finite and infinite sets. It is shown that they form a complete
  2658 lattice.
  2659 
  2660 * Class semiring_div requires superclass no_zero_divisors and proof of
  2661 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  2662 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  2663 generalized to class semiring_div, subsuming former theorems
  2664 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  2665 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  2666 INCOMPATIBILITY.
  2667 
  2668 * Refinements to lattice classes and sets:
  2669   - less default intro/elim rules in locale variant, more default
  2670     intro/elim rules in class variant: more uniformity
  2671   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  2672     le_inf_iff
  2673   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  2674     sup_aci)
  2675   - renamed ACI to inf_sup_aci
  2676   - new class "boolean_algebra"
  2677   - class "complete_lattice" moved to separate theory
  2678     "Complete_Lattice"; corresponding constants (and abbreviations)
  2679     renamed and with authentic syntax:
  2680     Set.Inf ~>    Complete_Lattice.Inf
  2681     Set.Sup ~>    Complete_Lattice.Sup
  2682     Set.INFI ~>   Complete_Lattice.INFI
  2683     Set.SUPR ~>   Complete_Lattice.SUPR
  2684     Set.Inter ~>  Complete_Lattice.Inter
  2685     Set.Union ~>  Complete_Lattice.Union
  2686     Set.INTER ~>  Complete_Lattice.INTER
  2687     Set.UNION ~>  Complete_Lattice.UNION
  2688   - authentic syntax for
  2689     Set.Pow
  2690     Set.image
  2691   - mere abbreviations:
  2692     Set.empty               (for bot)
  2693     Set.UNIV                (for top)
  2694     Set.inter               (for inf, formerly Set.Int)
  2695     Set.union               (for sup, formerly Set.Un)
  2696     Complete_Lattice.Inter  (for Inf)
  2697     Complete_Lattice.Union  (for Sup)
  2698     Complete_Lattice.INTER  (for INFI)
  2699     Complete_Lattice.UNION  (for SUPR)
  2700   - object-logic definitions as far as appropriate
  2701 
  2702 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  2703 Un_subset_iff are explicitly deleted as default simp rules; then also
  2704 their lattice counterparts le_inf_iff and le_sup_iff have to be
  2705 deleted to achieve the desired effect.
  2706 
  2707 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  2708 rules by default any longer; the same applies to min_max.inf_absorb1
  2709 etc.  INCOMPATIBILITY.
  2710 
  2711 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  2712 pred_set_conv by default.  INCOMPATIBILITY.
  2713 
  2714 * Power operations on relations and functions are now one dedicated
  2715 constant "compow" with infix syntax "^^".  Power operation on
  2716 multiplicative monoids retains syntax "^" and is now defined generic
  2717 in class power.  INCOMPATIBILITY.
  2718 
  2719 * Relation composition "R O S" now has a more standard argument order:
  2720 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  2721 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  2722 break, since the O_assoc rule was not rewritten like this.  Fix using
  2723 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  2724 
  2725 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  2726 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  2727 INCOMPATIBILITY.
  2728 
  2729 * Most rules produced by inductive and datatype package have mandatory
  2730 prefixes.  INCOMPATIBILITY.
  2731 
  2732 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  2733 the attribute of the same name.  Each of the theorems in the list
  2734 DERIV_intros assumes composition with an additional function and
  2735 matches a variable to the derivative, which has to be solved by the
  2736 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  2737 of most elementary terms.  Former Maclauren.DERIV_tac and
  2738 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  2739 INCOMPATIBILITY.
  2740 
  2741 * Code generator attributes follow the usual underscore convention:
  2742     code_unfold     replaces    code unfold
  2743     code_post       replaces    code post
  2744     etc.
  2745   INCOMPATIBILITY.
  2746 
  2747 * Renamed methods:
  2748     sizechange -> size_change
  2749     induct_scheme -> induction_schema
  2750   INCOMPATIBILITY.
  2751 
  2752 * Discontinued abbreviation "arbitrary" of constant "undefined".
  2753 INCOMPATIBILITY, use "undefined" directly.
  2754 
  2755 * Renamed theorems:
  2756     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  2757     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  2758     Suc_plus1 -> Suc_eq_plus1
  2759     *anti_sym -> *antisym*
  2760     vector_less_eq_def -> vector_le_def
  2761   INCOMPATIBILITY.
  2762 
  2763 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  2764 INCOMPATIBILITY.
  2765 
  2766 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  2767 INCOMPATIBILITY.
  2768 
  2769 
  2770 *** HOLCF ***
  2771 
  2772 * Theory Representable defines a class "rep" of domains that are
  2773 representable (via an ep-pair) in the universal domain type "udom".
  2774 Instances are provided for all type constructors defined in HOLCF.
  2775 
  2776 * The 'new_domain' command is a purely definitional version of the
  2777 domain package, for representable domains.  Syntax is identical to the
  2778 old domain package.  The 'new_domain' package also supports indirect
  2779 recursion using previously-defined type constructors.  See
  2780 src/HOLCF/ex/New_Domain.thy for examples.
  2781 
  2782 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  2783 on the left-hand side of an equation, and then performs
  2784 simplification.  Rewriting is done using rules declared with the
  2785 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  2786 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  2787 
  2788 * The pattern-match compiler in 'fixrec' can now handle constructors
  2789 with HOL function types.  Pattern-match combinators for the Pair
  2790 constructor are pre-configured.
  2791 
  2792 * The 'fixrec' package now produces better fixed-point induction rules
  2793 for mutually-recursive definitions:  Induction rules have conclusions
  2794 of the form "P foo bar" instead of "P <foo, bar>".
  2795 
  2796 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  2797 been renamed to "below".  The name "below" now replaces "less" in many
  2798 theorem names.  (Legacy theorem names using "less" are still supported
  2799 as well.)
  2800 
  2801 * The 'fixrec' package now supports "bottom patterns".  Bottom
  2802 patterns can be used to generate strictness rules, or to make
  2803 functions more strict (much like the bang-patterns supported by the
  2804 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  2805 examples.
  2806 
  2807 
  2808 *** ML ***
  2809 
  2810 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  2811 errors and run-time exceptions, including detailed source positions.
  2812 
  2813 * Structure Name_Space (formerly NameSpace) now manages uniquely
  2814 identified entries, with some additional information such as source
  2815 position, logical grouping etc.
  2816 
  2817 * Theory and context data is now introduced by the simplified and
  2818 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  2819 to be pure, but the old TheoryDataFun for mutable data (with explicit
  2820 copy operation) is still available for some time.
  2821 
  2822 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2823 provides a high-level programming interface to synchronized state
  2824 variables with atomic update.  This works via pure function
  2825 application within a critical section -- its runtime should be as
  2826 short as possible; beware of deadlocks if critical code is nested,
  2827 either directly or indirectly via other synchronized variables!
  2828 
  2829 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2830 wraps raw ML references, explicitly indicating their non-thread-safe
  2831 behaviour.  The Isar toplevel keeps this structure open, to
  2832 accommodate Proof General as well as quick and dirty interactive
  2833 experiments with references.
  2834 
  2835 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2836 parallel tactical reasoning.
  2837 
  2838 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2839 are similar to SUBPROOF, but are slightly more flexible: only the
  2840 specified parts of the subgoal are imported into the context, and the
  2841 body tactic may introduce new subgoals and schematic variables.
  2842 
  2843 * Old tactical METAHYPS, which does not observe the proof context, has
  2844 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2845 or Subgoal.FOCUS etc.
  2846 
  2847 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2848 functors have their own ML name space there is no point to mark them
  2849 separately.)  Minor INCOMPATIBILITY.
  2850 
  2851 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2852 
  2853 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2854 INCOMPATIBILITY.
  2855 
  2856 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2857 mode, which avoids critical setmp.
  2858 
  2859 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2860 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2861 Attrib/Method.setup introduced in Isabelle2009.
  2862 
  2863 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2864 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2865 last resort.  INCOMPATIBILITY.
  2866 
  2867 * Display.pretty_thm now requires a proper context (cf. former
  2868 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2869 or even Display.pretty_thm_without_context as last resort.
  2870 INCOMPATIBILITY.
  2871 
  2872 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2873 Syntax.pretty_typ/term directly, preferably with proper context
  2874 instead of global theory.
  2875 
  2876 
  2877 *** System ***
  2878 
  2879 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2880 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2881 usedir option -q.
  2882 
  2883 * Support for additional "Isabelle components" via etc/components, see
  2884 also the system manual.
  2885 
  2886 * The isabelle makeall tool now operates on all components with
  2887 IsaMakefile, not just hardwired "logics".
  2888 
  2889 * Removed "compress" option from isabelle-process and isabelle usedir;
  2890 this is always enabled.
  2891 
  2892 * Discontinued support for Poly/ML 4.x versions.
  2893 
  2894 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2895 on a given logic image.  This requires the lighttpd webserver and is
  2896 currently supported on Linux only.
  2897 
  2898 
  2899 
  2900 New in Isabelle2009 (April 2009)
  2901 --------------------------------
  2902 
  2903 *** General ***
  2904 
  2905 * Simplified main Isabelle executables, with less surprises on
  2906 case-insensitive file-systems (such as Mac OS).
  2907 
  2908   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2909     "isatool."
  2910 
  2911   - The former "isabelle" alias for "isabelle-process" has been
  2912     removed (should rarely occur to regular users).
  2913 
  2914   - The former "isabelle-interface" and its alias "Isabelle" have been
  2915     removed (interfaces are now regular Isabelle tools).
  2916 
  2917 Within scripts and make files, the Isabelle environment variables
  2918 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2919 respectively.  (The latter are still available as legacy feature.)
  2920 
  2921 The old isabelle-interface wrapper could react in confusing ways if
  2922 the interface was uninstalled or changed otherwise.  Individual
  2923 interface tool configuration is now more explicit, see also the
  2924 Isabelle system manual.  In particular, Proof General is now available
  2925 via "isabelle emacs".
  2926 
  2927 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2928 purge installed copies of Isabelle executables and re-run "isabelle
  2929 install -p ...", or use symlinks.
  2930 
  2931 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2932 old ~/isabelle, which was slightly non-standard and apt to cause
  2933 surprises on case-insensitive file-systems (such as Mac OS).
  2934 
  2935 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2936 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2937 care is required when using older releases of Isabelle.  Note that
  2938 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2939 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2940 
  2941 * Proofs of fully specified statements are run in parallel on
  2942 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2943 a regular 4-core machine, if the initial heap space is made reasonably
  2944 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2945 
  2946 * The main reference manuals ("isar-ref", "implementation", and
  2947 "system") have been updated and extended.  Formally checked references
  2948 as hyperlinks are now available uniformly.
  2949 
  2950 
  2951 *** Pure ***
  2952 
  2953 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2954 respects.  The most important changes are listed below.  See the
  2955 Tutorial on Locales ("locales" manual) for details.
  2956 
  2957 - In locale expressions, instantiation replaces renaming.  Parameters
  2958 must be declared in a for clause.  To aid compatibility with previous
  2959 parameter inheritance, in locale declarations, parameters that are not
  2960 'touched' (instantiation position "_" or omitted) are implicitly added
  2961 with their syntax at the beginning of the for clause.
  2962 
  2963 - Syntax from abbreviations and definitions in locales is available in
  2964 locale expressions and context elements.  The latter is particularly
  2965 useful in locale declarations.
  2966 
  2967 - More flexible mechanisms to qualify names generated by locale
  2968 expressions.  Qualifiers (prefixes) may be specified in locale
  2969 expressions, and can be marked as mandatory (syntax: "name!:") or
  2970 optional (syntax "name?:").  The default depends for plain "name:"
  2971 depends on the situation where a locale expression is used: in
  2972 commands 'locale' and 'sublocale' prefixes are optional, in
  2973 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2974 implicit qualifiers derived from the parameter names of a locale are
  2975 no longer generated.
  2976 
  2977 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2978 instantiation clause in "interpretation" and "interpret" (square
  2979 brackets) is no longer available.  Use locale expressions.
  2980 
  2981 - When converting proof scripts, mandatory qualifiers in
  2982 'interpretation' and 'interpret' should be retained by default, even
  2983 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2984 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2985 in locale expressions range over a single locale instance only.
  2986 
  2987 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2988 In existing theorem specifications replace the includes element by the
  2989 respective context elements of the included locale, omitting those
  2990 that are already present in the theorem specification.  Multiple
  2991 assume elements of a locale should be replaced by a single one
  2992 involving the locale predicate.  In the proof body, declarations (most
  2993 notably theorems) may be regained by interpreting the respective
  2994 locales in the proof context as required (command "interpret").
  2995 
  2996 If using "includes" in replacement of a target solely because the
  2997 parameter types in the theorem are not as general as in the target,
  2998 consider declaring a new locale with additional type constraints on
  2999 the parameters (context element "constrains").
  3000 
  3001 - Discontinued "locale (open)".  INCOMPATIBILITY.
  3002 
  3003 - Locale interpretation commands no longer attempt to simplify goal.
  3004 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  3005 methods intro_locales and unfold_locales to clarify.
  3006 
  3007 - Locale interpretation commands no longer accept interpretation
  3008 attributes.  INCOMPATIBILITY.
  3009 
  3010 * Class declaration: so-called "base sort" must not be given in import
  3011 list any longer, but is inferred from the specification.  Particularly
  3012 in HOL, write
  3013 
  3014     class foo = ...
  3015 
  3016 instead of
  3017 
  3018     class foo = type + ...
  3019 
  3020 * Class target: global versions of theorems stemming do not carry a
  3021 parameter prefix any longer.  INCOMPATIBILITY.
  3022 
  3023 * Class 'instance' command no longer accepts attached definitions.
  3024 INCOMPATIBILITY, use proper 'instantiation' target instead.
  3025 
  3026 * Recovered hiding of consts, which was accidentally broken in
  3027 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  3028 makes c inaccessible; consider using ``hide (open) const c'' instead.
  3029 
  3030 * Slightly more coherent Pure syntax, with updated documentation in
  3031 isar-ref manual.  Removed locales meta_term_syntax and
  3032 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  3033 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  3034 directly in regular applications.
  3035 
  3036 * There is a new syntactic category "float_const" for signed decimal
  3037 fractions (e.g. 123.45 or -123.45).
  3038 
  3039 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  3040 interface with 'setup' command instead.
  3041 
  3042 * Command 'local_setup' is similar to 'setup', but operates on a local
  3043 theory context.
  3044 
  3045 * The 'axiomatization' command now only works within a global theory
  3046 context.  INCOMPATIBILITY.
  3047 
  3048 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  3049 hypotheses.  Sorts required in the course of reasoning need to be
  3050 covered by the constraints in the initial statement, completed by the
  3051 type instance information of the background theory.  Non-trivial sort
  3052 hypotheses, which rarely occur in practice, may be specified via
  3053 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  3054 
  3055   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  3056 
  3057 The result contains an implicit sort hypotheses as before --
  3058 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  3059 normalization.
  3060 
  3061 * Generalized Isar history, with support for linear undo, direct state
  3062 addressing etc.
  3063 
  3064 * Changed defaults for unify configuration options:
  3065 
  3066   unify_trace_bound = 50 (formerly 25)
  3067   unify_search_bound = 60 (formerly 30)
  3068 
  3069 * Different bookkeeping for code equations (INCOMPATIBILITY):
  3070 
  3071   a) On theory merge, the last set of code equations for a particular
  3072      constant is taken (in accordance with the policy applied by other
  3073      parts of the code generator framework).
  3074 
  3075   b) Code equations stemming from explicit declarations (e.g. code
  3076      attribute) gain priority over default code equations stemming
  3077      from definition, primrec, fun etc.
  3078 
  3079 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  3080 
  3081 * Unified theorem tables for both code generators.  Thus [code
  3082 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  3083 
  3084 * Command 'find_consts' searches for constants based on type and name
  3085 patterns, e.g.
  3086 
  3087     find_consts "_ => bool"
  3088 
  3089 By default, matching is against subtypes, but it may be restricted to
  3090 the whole type.  Searching by name is possible.  Multiple queries are
  3091 conjunctive and queries may be negated by prefixing them with a
  3092 hyphen:
  3093 
  3094     find_consts strict: "_ => bool" name: "Int" -"int => int"
  3095 
  3096 * New 'find_theorems' criterion "solves" matches theorems that
  3097 directly solve the current goal (modulo higher-order unification).
  3098 
  3099 * Auto solve feature for main theorem statements: whenever a new goal
  3100 is stated, "find_theorems solves" is called; any theorems that could
  3101 solve the lemma directly are listed as part of the goal state.
  3102 Cf. associated options in Proof General Isabelle settings menu,
  3103 enabled by default, with reasonable timeout for pathological cases of
  3104 higher-order unification.
  3105 
  3106 
  3107 *** Document preparation ***
  3108 
  3109 * Antiquotation @{lemma} now imitates a regular terminal proof,
  3110 demanding keyword 'by' and supporting the full method expression
  3111 syntax just like the Isar command 'by'.
  3112 
  3113 
  3114 *** HOL ***
  3115 
  3116 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  3117 points Main and Complex_Main remain as before.
  3118 
  3119 * Logic image HOL-Plain provides a minimal HOL with the most important
  3120 tools available (inductive, datatype, primrec, ...).  This facilitates
  3121 experimentation and tool development.  Note that user applications
  3122 (and library theories) should never refer to anything below theory
  3123 Main, as before.
  3124 
  3125 * Logic image HOL-Main stops at theory Main, and thus facilitates
  3126 experimentation due to shorter build times.
  3127 
  3128 * Logic image HOL-NSA contains theories of nonstandard analysis which
  3129 were previously part of former HOL-Complex.  Entry point Hyperreal
  3130 remains valid, but theories formerly using Complex_Main should now use
  3131 new entry point Hypercomplex.
  3132 
  3133 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  3134 Posix processes.  Avoids potentially expensive forking of the ML
  3135 process.  New thread-based implementation also works on non-Unix
  3136 platforms (Cygwin).  Provers are no longer hardwired, but defined
  3137 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  3138 commands are covered in the isar-ref manual.
  3139 
  3140 * Wrapper scripts for remote SystemOnTPTP service allows to use
  3141 sledgehammer without local ATP installation (Vampire etc.). Other
  3142 provers may be included via suitable ML wrappers, see also
  3143 src/HOL/ATP_Linkup.thy.
  3144 
  3145 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  3146 menu.
  3147 
  3148 * The metis method no longer fails because the theorem is too trivial
  3149 (contains the empty clause).
  3150 
  3151 * The metis method now fails in the usual manner, rather than raising
  3152 an exception, if it determines that it cannot prove the theorem.
  3153 
  3154 * Method "coherent" implements a prover for coherent logic (see also
  3155 src/Tools/coherent.ML).
  3156 
  3157 * Constants "undefined" and "default" replace "arbitrary".  Usually
  3158 "undefined" is the right choice to replace "arbitrary", though
  3159 logically there is no difference.  INCOMPATIBILITY.
  3160 
  3161 * Command "value" now integrates different evaluation mechanisms.  The
  3162 result of the first successful evaluation mechanism is printed.  In
  3163 square brackets a particular named evaluation mechanisms may be
  3164 specified (currently, [SML], [code] or [nbe]).  See further
  3165 src/HOL/ex/Eval_Examples.thy.
  3166 
  3167 * Normalization by evaluation now allows non-leftlinear equations.
  3168 Declare with attribute [code nbe].
  3169 
  3170 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  3171 as the structured Isar versions "cases" and "induct", cf. the
  3172 corresponding "cases" and "induct" attributes.  Mutual induction rules
  3173 are now presented as a list of individual projections
  3174 (e.g. foo_bar.inducts for types foo and bar); the old format with
  3175 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  3176 rare situations a different rule is selected --- notably nested tuple
  3177 elimination instead of former prod.exhaust: use explicit (case_tac t
  3178 rule: prod.exhaust) here.
  3179 
  3180 * Attributes "cases", "induct", "coinduct" support "del" option.
  3181 
  3182 * Removed fact "case_split_thm", which duplicates "case_split".
  3183 
  3184 * The option datatype has been moved to a new theory Option.  Renamed
  3185 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  3186 
  3187 * New predicate "strict_mono" classifies strict functions on partial
  3188 orders.  With strict functions on linear orders, reasoning about
  3189 (in)equalities is facilitated by theorems "strict_mono_eq",
  3190 "strict_mono_less_eq" and "strict_mono_less".
  3191 
  3192 * Some set operations are now proper qualified constants with
  3193 authentic syntax.  INCOMPATIBILITY:
  3194 
  3195     op Int ~>   Set.Int
  3196     op Un ~>    Set.Un
  3197     INTER ~>    Set.INTER
  3198     UNION ~>    Set.UNION
  3199     Inter ~>    Set.Inter
  3200     Union ~>    Set.Union
  3201     {} ~>       Set.empty
  3202     UNIV ~>     Set.UNIV
  3203 
  3204 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  3205 theory Set.
  3206 
  3207 * Auxiliary class "itself" has disappeared -- classes without any
  3208 parameter are treated as expected by the 'class' command.
  3209 
  3210 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  3211 
  3212 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  3213 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  3214 
  3215 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  3216 method "approximation".  It proves formulas on real values by using
  3217 interval arithmetic.  In the formulas are also the transcendental
  3218 functions sin, cos, tan, atan, ln, exp and the constant pi are
  3219 allowed. For examples see
  3220 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  3221 
  3222 * Theory "Reflection" now resides in HOL/Library.
  3223 
  3224 * Entry point to Word library now simply named "Word".
  3225 INCOMPATIBILITY.
  3226 
  3227 * Made source layout more coherent with logical distribution
  3228 structure:
  3229 
  3230     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  3231     src/HOL/Library/Code_Message.thy ~> src/HOL/
  3232     src/HOL/Library/GCD.thy ~> src/HOL/
  3233     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  3234     src/HOL/Library/Parity.thy ~> src/HOL/
  3235     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  3236     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  3237     src/HOL/Real/Lubs.thy ~> src/HOL/
  3238     src/HOL/Real/PReal.thy ~> src/HOL/
  3239     src/HOL/Real/Rational.thy ~> src/HOL/
  3240     src/HOL/Real/RComplete.thy ~> src/HOL/
  3241     src/HOL/Real/RealDef.thy ~> src/HOL/
  3242     src/HOL/Real/RealPow.thy ~> src/HOL/
  3243     src/HOL/Real/Real.thy ~> src/HOL/
  3244     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  3245     src/HOL/Complex/Complex.thy ~> src/HOL/
  3246     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  3247     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  3248     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  3249     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  3250     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  3251     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  3252     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  3253     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  3254     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  3255     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  3256     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  3257     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  3258     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  3259     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  3260     src/HOL/Real/Float ~> src/HOL/Library/
  3261     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  3262     src/HOL/Real/RealVector.thy ~> src/HOL/
  3263 
  3264     src/HOL/arith_data.ML ~> src/HOL/Tools
  3265     src/HOL/hologic.ML ~> src/HOL/Tools
  3266     src/HOL/simpdata.ML ~> src/HOL/Tools
  3267     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  3268     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  3269     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  3270     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  3271     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  3272     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  3273     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  3274 
  3275     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  3276     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3277     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3278     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3279     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3280     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3281 
  3282 * If methods "eval" and "evaluation" encounter a structured proof
  3283 state with !!/==>, only the conclusion is evaluated to True (if
  3284 possible), avoiding strange error messages.
  3285 
  3286 * Method "sizechange" automates termination proofs using (a
  3287 modification of) the size-change principle.  Requires SAT solver.  See
  3288 src/HOL/ex/Termination.thy for examples.
  3289 
  3290 * Simplifier: simproc for let expressions now unfolds if bound
  3291 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3292 
  3293 * Method "arith": Linear arithmetic now ignores all inequalities when
  3294 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3295 
  3296 * New attribute "arith" for facts that should always be used
  3297 automatically by arithmetic. It is intended to be used locally in
  3298 proofs, e.g.
  3299 
  3300   assumes [arith]: "x > 0"
  3301 
  3302 Global usage is discouraged because of possible performance impact.
  3303 
  3304 * New classes "top" and "bot" with corresponding operations "top" and
  3305 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3306 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3307 
  3308 * Changed definition lemma "less_fun_def" in order to provide an
  3309 instance for preorders on functions; use lemma "less_le" instead.
  3310 INCOMPATIBILITY.
  3311 
  3312 * Theory Orderings: class "wellorder" moved here, with explicit
  3313 induction rule "less_induct" as assumption.  For instantiation of
  3314 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3315 INCOMPATIBILITY.
  3316 
  3317 * Theory Orderings: added class "preorder" as superclass of "order".
  3318 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3319 etc. slightly changed.  Some theorems named order_class.* now named
  3320 preorder_class.*.
  3321 
  3322 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3323 "diag" to "Id_on".
  3324 
  3325 * Theory Finite_Set: added a new fold combinator of type
  3326 
  3327   ('a => 'b => 'b) => 'b => 'a set => 'b
  3328 
  3329 Occasionally this is more convenient than the old fold combinator
  3330 which is now defined in terms of the new one and renamed to
  3331 fold_image.
  3332 
  3333 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3334 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3335 extended with further lemmas!).  At the moment both still exist but
  3336 the former will disappear at some point.
  3337 
  3338 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3339 class recpower.  Type-specific simp rules for various recpower types
  3340 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3341 
  3342 rat_power_0    -> power_0
  3343 rat_power_Suc  -> power_Suc
  3344 realpow_0      -> power_0
  3345 realpow_Suc    -> power_Suc
  3346 complexpow_0   -> power_0
  3347 complexpow_Suc -> power_Suc
  3348 power_poly_0   -> power_0
  3349 power_poly_Suc -> power_Suc
  3350 
  3351 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3352 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3353 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3354 of lemmas from Divides has been generalized from nat to class
  3355 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3356 renames resulting from duplicate elimination:
  3357 
  3358     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3359     zero_dvd_iff ~>         dvd_0_left_iff
  3360     dvd_0 ~>                dvd_0_right
  3361     DIVISION_BY_ZERO_DIV ~> div_by_0
  3362     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3363     mult_div ~>             div_mult_self2_is_id
  3364     mult_mod ~>             mod_mult_self2_is_0
  3365 
  3366 * Theory IntDiv: removed many lemmas that are instances of class-based
  3367 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3368 rename old lemmas as follows:
  3369 
  3370 dvd_diff               -> nat_dvd_diff
  3371 dvd_zminus_iff         -> dvd_minus_iff
  3372 mod_add1_eq            -> mod_add_eq
  3373 mod_mult1_eq           -> mod_mult_right_eq
  3374 mod_mult1_eq'          -> mod_mult_left_eq
  3375 mod_mult_distrib_mod   -> mod_mult_eq
  3376 nat_mod_add_left_eq    -> mod_add_left_eq
  3377 nat_mod_add_right_eq   -> mod_add_right_eq
  3378 nat_mod_div_trivial    -> mod_div_trivial
  3379 nat_mod_mod_trivial    -> mod_mod_trivial
  3380 zdiv_zadd_self1        -> div_add_self1
  3381 zdiv_zadd_self2        -> div_add_self2
  3382 zdiv_zmult_self1       -> div_mult_self2_is_id
  3383 zdiv_zmult_self2       -> div_mult_self1_is_id
  3384 zdvd_triv_left         -> dvd_triv_left
  3385 zdvd_triv_right        -> dvd_triv_right
  3386 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3387 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3388 zmod_zadd_left_eq      -> mod_add_left_eq
  3389 zmod_zadd_right_eq     -> mod_add_right_eq
  3390 zmod_zadd_self1        -> mod_add_self1
  3391 zmod_zadd_self2        -> mod_add_self2
  3392 zmod_zadd1_eq          -> mod_add_eq
  3393 zmod_zdiff1_eq         -> mod_diff_eq
  3394 zmod_zdvd_zmod         -> mod_mod_cancel
  3395 zmod_zmod_cancel       -> mod_mod_cancel
  3396 zmod_zmult_self1       -> mod_mult_self2_is_0
  3397 zmod_zmult_self2       -> mod_mult_self1_is_0
  3398 zmod_1                 -> mod_by_1
  3399 zdiv_1                 -> div_by_1
  3400 zdvd_abs1              -> abs_dvd_iff
  3401 zdvd_abs2              -> dvd_abs_iff
  3402 zdvd_refl              -> dvd_refl
  3403 zdvd_trans             -> dvd_trans
  3404 zdvd_zadd              -> dvd_add
  3405 zdvd_zdiff             -> dvd_diff
  3406 zdvd_zminus_iff        -> dvd_minus_iff
  3407 zdvd_zminus2_iff       -> minus_dvd_iff
  3408 zdvd_zmultD            -> dvd_mult_right
  3409 zdvd_zmultD2           -> dvd_mult_left
  3410 zdvd_zmult_mono        -> mult_dvd_mono
  3411 zdvd_0_right           -> dvd_0_right
  3412 zdvd_0_left            -> dvd_0_left_iff
  3413 zdvd_1_left            -> one_dvd
  3414 zminus_dvd_iff         -> minus_dvd_iff
  3415 
  3416 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3417 
  3418 * The real numbers offer decimal input syntax: 12.34 is translated
  3419 into 1234/10^2. This translation is not reversed upon output.
  3420 
  3421 * Theory Library/Polynomial defines an abstract type 'a poly of
  3422 univariate polynomials with coefficients of type 'a.  In addition to
  3423 the standard ring operations, it also supports div and mod.  Code
  3424 generation is also supported, using list-style constructors.
  3425 
  3426 * Theory Library/Inner_Product defines a class of real_inner for real
  3427 inner product spaces, with an overloaded operation inner :: 'a => 'a
  3428 => real.  Class real_inner is a subclass of real_normed_vector from
  3429 theory RealVector.
  3430 
  3431 * Theory Library/Product_Vector provides instances for the product
  3432 type 'a * 'b of several classes from RealVector and Inner_Product.
  3433 Definitions of addition, subtraction, scalar multiplication, norms,
  3434 and inner products are included.
  3435 
  3436 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  3437 addition to the field operations, numerals and case syntax are also
  3438 supported.
  3439 
  3440 * Theory Library/Diagonalize provides constructive version of Cantor's
  3441 first diagonalization argument.
  3442 
  3443 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  3444 zlcm (for int); carried together from various gcd/lcm developements in
  3445 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  3446 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  3447 may recover tupled syntax as follows:
  3448 
  3449     hide (open) const gcd
  3450     abbreviation gcd where
  3451       "gcd == (%(a, b). GCD.gcd a b)"
  3452     notation (output)
  3453       GCD.gcd ("gcd '(_, _')")
  3454 
  3455 The same works for lcm, zgcd, zlcm.
  3456 
  3457 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  3458 instantiations for algebraic structures.  Removed some duplicate
  3459 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  3460 
  3461 * ML antiquotation @{code} takes a constant as argument and generates
  3462 corresponding code in background and inserts name of the corresponding
  3463 resulting ML value/function/datatype constructor binding in place.
  3464 All occurrences of @{code} with a single ML block are generated
  3465 simultaneously.  Provides a generic and safe interface for
  3466 instrumentalizing code generation.  See
  3467 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  3468 In future you ought to refrain from ad-hoc compiling generated SML
  3469 code on the ML toplevel.  Note that (for technical reasons) @{code}
  3470 cannot refer to constants for which user-defined serializations are
  3471 set.  Refer to the corresponding ML counterpart directly in that
  3472 cases.
  3473 
  3474 * Command 'rep_datatype': instead of theorem names the command now
  3475 takes a list of terms denoting the constructors of the type to be
  3476 represented as datatype.  The characteristic theorems have to be
  3477 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  3478 have disappeared in favour of existing ones:
  3479 
  3480     unit_induct                 ~> unit.induct
  3481     prod_induct                 ~> prod.induct
  3482     sum_induct                  ~> sum.induct
  3483     Suc_Suc_eq                  ~> nat.inject
  3484     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  3485 
  3486 
  3487 *** HOL-Algebra ***
  3488 
  3489 * New locales for orders and lattices where the equivalence relation
  3490 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  3491 locales use a record structure with field eq for the equivalence.
  3492 
  3493 * New theory of factorial domains.
  3494 
  3495 * Units_l_inv and Units_r_inv are now simp rules by default.
  3496 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  3497 and/or r_inv will now also require deletion of these lemmas.
  3498 
  3499 * Renamed the following theorems, INCOMPATIBILITY:
  3500 
  3501 UpperD ~> Upper_memD
  3502 LowerD ~> Lower_memD
  3503 least_carrier ~> least_closed
  3504 greatest_carrier ~> greatest_closed
  3505 greatest_Lower_above ~> greatest_Lower_below
  3506 one_zero ~> carrier_one_zero
  3507 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  3508 
  3509 
  3510 *** HOL-Nominal ***
  3511 
  3512 * Nominal datatypes can now contain type-variables.
  3513 
  3514 * Commands 'nominal_inductive' and 'equivariance' work with local
  3515 theory targets.
  3516 
  3517 * Nominal primrec can now works with local theory targets and its
  3518 specification syntax now conforms to the general format as seen in
  3519 'inductive' etc.
  3520 
  3521 * Method "perm_simp" honours the standard simplifier attributes
  3522 (no_asm), (no_asm_use) etc.
  3523 
  3524 * The new predicate #* is defined like freshness, except that on the
  3525 left hand side can be a set or list of atoms.
  3526 
  3527 * Experimental command 'nominal_inductive2' derives strong induction
  3528 principles for inductive definitions.  In contrast to
  3529 'nominal_inductive', which can only deal with a fixed number of
  3530 binders, it can deal with arbitrary expressions standing for sets of
  3531 atoms to be avoided.  The only inductive definition we have at the
  3532 moment that needs this generalisation is the typing rule for Lets in
  3533 the algorithm W:
  3534 
  3535  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  3536  -----------------------------------------------------------------
  3537          Gamma |- Let x be t1 in t2 : T2
  3538 
  3539 In this rule one wants to avoid all the binders that are introduced by
  3540 "close Gamma T1".  We are looking for other examples where this
  3541 feature might be useful.  Please let us know.
  3542 
  3543 
  3544 *** HOLCF ***
  3545 
  3546 * Reimplemented the simplification procedure for proving continuity
  3547 subgoals.  The new simproc is extensible; users can declare additional
  3548 continuity introduction rules with the attribute [cont2cont].
  3549 
  3550 * The continuity simproc now uses a different introduction rule for
  3551 solving continuity subgoals on terms with lambda abstractions.  In
  3552 some rare cases the new simproc may fail to solve subgoals that the
  3553 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  3554 Potential INCOMPATIBILITY.
  3555 
  3556 * Command 'fixrec': specification syntax now conforms to the general
  3557 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  3558 examples.  INCOMPATIBILITY.
  3559 
  3560 
  3561 *** ZF ***
  3562 
  3563 * Proof of Zorn's Lemma for partial orders.
  3564 
  3565 
  3566 *** ML ***
  3567 
  3568 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  3569 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  3570 depends on multithreading, so timouts will not work before Poly/ML
  3571 5.2.1!
  3572 
  3573 * High-level support for concurrent ML programming, see
  3574 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  3575 particularly convenient to organize independent functional
  3576 computations.  The concept of "synchronized variables" provides a
  3577 higher-order interface for components with shared state, avoiding the
  3578 delicate details of mutexes and condition variables.  (Requires
  3579 Poly/ML 5.2.1 or later.)
  3580 
  3581 * ML bindings produced via Isar commands are stored within the Isar
  3582 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  3583 become thread-safe and work with undo as expected (concerning
  3584 top-level bindings, not side-effects on global references).
  3585 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  3586 compiler at runtime; really global bindings need to be given outside a
  3587 theory.  (Requires Poly/ML 5.2 or later.)
  3588 
  3589 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  3590 context.  Top-level ML bindings are stored within the proof context in
  3591 a purely sequential fashion, disregarding the nested proof structure.
  3592 ML bindings introduced by 'ML_prf' are discarded at the end of the
  3593 proof.  (Requires Poly/ML 5.2 or later.)
  3594 
  3595 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  3596 and Method.setup, as well as Isar commands 'attribute_setup' and
  3597 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  3598 existing code accordingly, or use plain 'setup' together with old
  3599 Method.add_method.
  3600 
  3601 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  3602 to 'a -> thm, while results are always tagged with an authentic oracle
  3603 name.  The Isar command 'oracle' is now polymorphic, no argument type
  3604 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  3605 accordingly.  Note that extra performance may be gained by producing
  3606 the cterm carefully, avoiding slow Thm.cterm_of.
  3607 
  3608 * Simplified interface for defining document antiquotations via
  3609 ThyOutput.antiquotation, ThyOutput.output, and optionally
  3610 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  3611 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  3612 examples.
  3613 
  3614 * More systematic treatment of long names, abstract name bindings, and
  3615 name space operations.  Basic operations on qualified names have been
  3616 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  3617 Long_Name.append.  Old type bstring has been mostly replaced by
  3618 abstract type binding (see structure Binding), which supports precise
  3619 qualification by packages and local theory targets, as well as proper
  3620 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  3621 bstring values into Binding.name, or better pass through abstract
  3622 bindings everywhere.  See further src/Pure/General/long_name.ML,
  3623 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  3624 
  3625 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  3626 LocalTheory.note etc.) now refer to the *full* internal name, not the
  3627 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  3628 
  3629 * Disposed old type and term read functions (Sign.read_def_typ,
  3630 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  3631 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  3632 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  3633 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  3634 resort for legacy applications.
  3635 
  3636 * Disposed old declarations, tactics, tactic combinators that refer to
  3637 the simpset or claset of an implicit theory (such as Addsimps,
  3638 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  3639 embedded ML text, or local_simpset_of with a proper context passed as
  3640 explicit runtime argument.
  3641 
  3642 * Rules and tactics that read instantiations (read_instantiate,
  3643 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  3644 context, which is required for parsing and type-checking.  Moreover,
  3645 the variables are specified as plain indexnames, not string encodings
  3646 thereof.  INCOMPATIBILITY.
  3647 
  3648 * Generic Toplevel.add_hook interface allows to analyze the result of
  3649 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  3650 for theorem dependency output of transactions resulting in a new
  3651 theory state.
  3652 
  3653 * ML antiquotations: block-structured compilation context indicated by
  3654 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  3655 
  3656   @{binding name}                         - basic name binding
  3657   @{let ?pat = term}                      - term abbreviation (HO matching)
  3658   @{note name = fact}                     - fact abbreviation
  3659   @{thm fact}                             - singleton fact (with attributes)
  3660   @{thms fact}                            - general fact (with attributes)
  3661   @{lemma prop by method}                 - singleton goal
  3662   @{lemma prop by meth1 meth2}            - singleton goal
  3663   @{lemma prop1 ... propN by method}      - general goal
  3664   @{lemma prop1 ... propN by meth1 meth2} - general goal
  3665   @{lemma (open) ...}                     - open derivation
  3666 
  3667 
  3668 *** System ***
  3669 
  3670 * The Isabelle "emacs" tool provides a specific interface to invoke
  3671 Proof General / Emacs, with more explicit failure if that is not
  3672 installed (the old isabelle-interface script silently falls back on
  3673 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  3674 installation location of the Proof General distribution.
  3675 
  3676 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  3677 the Isabelle process into a JVM/Scala application.  See
  3678 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  3679 process wrapper has been discontinued.)
  3680 
  3681 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  3682 
  3683 * Various status messages (with exact source position information) are
  3684 emitted, if proper markup print mode is enabled.  This allows
  3685 user-interface components to provide detailed feedback on internal
  3686 prover operations.
  3687 
  3688 
  3689 
  3690 New in Isabelle2008 (June 2008)
  3691 -------------------------------
  3692 
  3693 *** General ***
  3694 
  3695 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  3696 and updated, with formally checked references as hyperlinks.
  3697 
  3698 * Theory loader: use_thy (and similar operations) no longer set the
  3699 implicit ML context, which was occasionally hard to predict and in
  3700 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  3701 provides a proper context already.
  3702 
  3703 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3704 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  3705 'use' within a theory file will do the job.
  3706 
  3707 * Name space merge now observes canonical order, i.e. the second space
  3708 is inserted into the first one, while existing entries in the first
  3709 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  3710 swap theory imports.
  3711 
  3712 * Syntax: symbol \<chi> is now considered a letter.  Potential
  3713 INCOMPATIBILITY in identifier syntax etc.
  3714 
  3715 * Outer syntax: string tokens no longer admit escaped white space,
  3716 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  3717 white space without escapes.
  3718 
  3719 * Outer syntax: string tokens may contain arbitrary character codes
  3720 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  3721 "foo_bar".
  3722 
  3723 
  3724 *** Pure ***
  3725 
  3726 * Context-dependent token translations.  Default setup reverts locally
  3727 fixed variables, and adds hilite markup for undeclared frees.
  3728 
  3729 * Unused theorems can be found using the new command 'unused_thms'.
  3730 There are three ways of invoking it:
  3731 
  3732 (1) unused_thms
  3733      Only finds unused theorems in the current theory.
  3734 
  3735 (2) unused_thms thy_1 ... thy_n -
  3736      Finds unused theorems in the current theory and all of its ancestors,
  3737      excluding the theories thy_1 ... thy_n and all of their ancestors.
  3738 
  3739 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  3740      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  3741      their ancestors, excluding the theories thy_1 ... thy_n and all of
  3742      their ancestors.
  3743 
  3744 In order to increase the readability of the list produced by
  3745 unused_thms, theorems that have been created by a particular instance
  3746 of a theory command such as 'inductive' or 'function' are considered
  3747 to belong to the same "group", meaning that if at least one theorem in
  3748 this group is used, the other theorems in the same group are no longer
  3749 reported as unused.  Moreover, if all theorems in the group are
  3750 unused, only one theorem in the group is displayed.
  3751 
  3752 Note that proof objects have to be switched on in order for
  3753 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  3754 usually the case when using Proof General with the default settings).
  3755 
  3756 * Authentic naming of facts disallows ad-hoc overwriting of previous
  3757 theorems within the same name space.  INCOMPATIBILITY, need to remove
  3758 duplicate fact bindings, or even accidental fact duplications.  Note
  3759 that tools may maintain dynamically scoped facts systematically, using
  3760 PureThy.add_thms_dynamic.
  3761 
  3762 * Command 'hide' now allows to hide from "fact" name space as well.
  3763 
  3764 * Eliminated destructive theorem database, simpset, claset, and
  3765 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  3766 update of theories within ML code.
  3767 
  3768 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  3769 INCOMPATIBILITY, object-logics depending on former Pure require
  3770 additional setup PureThy.old_appl_syntax_setup; object-logics
  3771 depending on former CPure need to refer to Pure.
  3772 
  3773 * Commands 'use' and 'ML' are now purely functional, operating on
  3774 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  3775 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  3776 INCOMPATIBILITY.
  3777 
  3778 * Command 'setup': discontinued implicit version with ML reference.
  3779 
  3780 * Instantiation target allows for simultaneous specification of class
  3781 instance operations together with an instantiation proof.
  3782 Type-checking phase allows to refer to class operations uniformly.
  3783 See src/HOL/Complex/Complex.thy for an Isar example and
  3784 src/HOL/Library/Eval.thy for an ML example.
  3785 
  3786 * Indexing of literal facts: be more serious about including only
  3787 facts from the visible specification/proof context, but not the
  3788 background context (locale etc.).  Affects `prop` notation and method
  3789 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  3790 situations.
  3791 
  3792 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  3793 "(open)" option, which used to expose internal bound variables to the
  3794 proof text.
  3795 
  3796 * Isar statements: removed obsolete case "rule_context".
  3797 INCOMPATIBILITY, better use explicit fixes/assumes.
  3798 
  3799 * Locale proofs: default proof step now includes 'unfold_locales';
  3800 hence 'proof' without argument may be used to unfold locale
  3801 predicates.
  3802 
  3803 
  3804 *** Document preparation ***
  3805 
  3806 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  3807 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  3808 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  3809 spot); renamed link color from "darkblue" to "linkcolor" (default
  3810 value unchanged, can be redefined via \definecolor); no longer sets
  3811 "a4paper" option (unnecessary or even intrusive).
  3812 
  3813 * Antiquotation @{lemma A method} proves proposition A by the given
  3814 method (either a method name or a method name plus (optional) method
  3815 arguments in parentheses) and prints A just like @{prop A}.
  3816 
  3817 
  3818 *** HOL ***
  3819 
  3820 * New primrec package.  Specification syntax conforms in style to
  3821 definition/function/....  No separate induction rule is provided.  The
  3822 "primrec" command distinguishes old-style and new-style specifications
  3823 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3824 When adjusting theories, beware: constants stemming from new-style
  3825 primrec specifications have authentic syntax.
  3826 
  3827 * Metis prover is now an order of magnitude faster, and also works
  3828 with multithreading.
  3829 
  3830 * Metis: the maximum number of clauses that can be produced from a
  3831 theorem is now given by the attribute max_clauses.  Theorems that
  3832 exceed this number are ignored, with a warning printed.
  3833 
  3834 * Sledgehammer no longer produces structured proofs by default. To
  3835 enable, declare [[sledgehammer_full = true]].  Attributes
  3836 reconstruction_modulus, reconstruction_sorts renamed
  3837 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3838 
  3839 * Method "induct_scheme" derives user-specified induction rules
  3840 from well-founded induction and completeness of patterns. This factors
  3841 out some operations that are done internally by the function package
  3842 and makes them available separately.  See
  3843 src/HOL/ex/Induction_Scheme.thy for examples.
  3844 
  3845 * More flexible generation of measure functions for termination
  3846 proofs: Measure functions can be declared by proving a rule of the
  3847 form "is_measure f" and giving it the [measure_function] attribute.
  3848 The "is_measure" predicate is logically meaningless (always true), and
  3849 just guides the heuristic.  To find suitable measure functions, the
  3850 termination prover sets up the goal "is_measure ?f" of the appropriate
  3851 type and generates all solutions by prolog-style backwards proof using
  3852 the declared rules.
  3853 
  3854 This setup also deals with rules like 
  3855 
  3856   "is_measure f ==> is_measure (list_size f)"
  3857 
  3858 which accommodates nested datatypes that recurse through lists.
  3859 Similar rules are predeclared for products and option types.
  3860 
  3861 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3862 
  3863   INCOMPATIBILITIES:
  3864 
  3865   - Definitions of overloaded constants on sets have to be replaced by
  3866     definitions on => and bool.
  3867 
  3868   - Some definitions of overloaded operators on sets can now be proved
  3869     using the definitions of the operators on => and bool.  Therefore,
  3870     the following theorems have been renamed:
  3871 
  3872       subset_def   -> subset_eq
  3873       psubset_def  -> psubset_eq
  3874       set_diff_def -> set_diff_eq
  3875       Compl_def    -> Compl_eq
  3876       Sup_set_def  -> Sup_set_eq
  3877       Inf_set_def  -> Inf_set_eq
  3878       sup_set_def  -> sup_set_eq
  3879       inf_set_def  -> inf_set_eq
  3880 
  3881   - Due to the incompleteness of the HO unification algorithm, some
  3882     rules such as subst may require manual instantiation, if some of
  3883     the unknowns in the rule is a set.
  3884 
  3885   - Higher order unification and forward proofs:
  3886     The proof pattern
  3887 
  3888       have "P (S::'a set)" <...>
  3889       then have "EX S. P S" ..
  3890 
  3891     no longer works (due to the incompleteness of the HO unification
  3892     algorithm) and must be replaced by the pattern
  3893 
  3894       have "EX S. P S"
  3895       proof
  3896         show "P S" <...>
  3897       qed
  3898 
  3899   - Calculational reasoning with subst (or similar rules):
  3900     The proof pattern
  3901 
  3902       have "P (S::'a set)" <...>
  3903       also have "S = T" <...>
  3904       finally have "P T" .
  3905 
  3906     no longer works (for similar reasons as the previous example) and
  3907     must be replaced by something like
  3908 
  3909       have "P (S::'a set)" <...>
  3910       moreover have "S = T" <...>
  3911       ultimately have "P T" by simp
  3912 
  3913   - Tactics or packages written in ML code:
  3914     Code performing pattern matching on types via
  3915 
  3916       Type ("set", [T]) => ...
  3917 
  3918     must be rewritten. Moreover, functions like strip_type or
  3919     binder_types no longer return the right value when applied to a
  3920     type of the form
  3921 
  3922       T1 => ... => Tn => U => bool
  3923 
  3924     rather than
  3925 
  3926       T1 => ... => Tn => U set
  3927 
  3928 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3929 Wellfounded_Relations to theory Wellfounded.
  3930 
  3931 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3932 
  3933 * Class finite no longer treats UNIV as class parameter.  Use class
  3934 enum from theory Library/Enum instead to achieve a similar effect.
  3935 INCOMPATIBILITY.
  3936 
  3937 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3938 and "Cons".  INCOMPATIBILITY.
  3939 
  3940 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3941 Potential INCOMPATIBILITY.
  3942 
  3943 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3944 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3945 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3946 
  3947 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3948 the same name in theory Orderings:
  3949 
  3950   less_trans
  3951   less_linear
  3952   le_imp_less_or_eq
  3953   le_less_trans
  3954   less_le_trans
  3955   less_not_sym
  3956   less_asym
  3957 
  3958 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3959 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3960 and different variable names.
  3961 
  3962 * Library/Option_ord.thy: Canonical order on option type.
  3963 
  3964 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3965 finite maps.
  3966 
  3967 * Library/Countable.thy: Type class for countable types.
  3968 
  3969 * Theory Int: The representation of numerals has changed.  The infix
  3970 operator BIT and the bit datatype with constructors B0 and B1 have
  3971 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3972 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3973 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3974 accordingly.
  3975 
  3976 * Theory Nat: definition of <= and < on natural numbers no longer
  3977 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3978 le_def and less_def have disappeared.  Consider lemmas not_less
  3979 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3980 
  3981 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3982 (whose purpose mainly is for various fold_set functionals) have been
  3983 abandoned in favor of the existing algebraic classes
  3984 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3985 lower_semilattice (resp. upper_semilattice) and linorder.
  3986 INCOMPATIBILITY.
  3987 
  3988 * Theory Transitive_Closure: induct and cases rules now declare proper
  3989 case_names ("base" and "step").  INCOMPATIBILITY.
  3990 
  3991 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3992 lattices.  The form set-specific version is available as
  3993 Inductive.lfp_ordinal_induct_set.
  3994 
  3995 * Renamed theorems "power.simps" to "power_int.simps".
  3996 INCOMPATIBILITY.
  3997 
  3998 * Class semiring_div provides basic abstract properties of semirings
  3999 with division and modulo operations.  Subsumes former class dvd_mod.
  4000 
  4001 * Merged theories IntDef, Numeral and IntArith into unified theory
  4002 Int.  INCOMPATIBILITY.
  4003 
  4004 * Theory Library/Code_Index: type "index" now represents natural
  4005 numbers rather than integers.  INCOMPATIBILITY.
  4006 
  4007 * New class "uminus" with operation "uminus" (split of from class
  4008 "minus" which now only has operation "minus", binary).
  4009 INCOMPATIBILITY.
  4010 
  4011 * Constants "card", "internal_split", "option_map" now with authentic
  4012 syntax.  INCOMPATIBILITY.
  4013 
  4014 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  4015 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  4016 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  4017 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  4018 Sup_set_def, le_def, less_def, option_map_def now with object
  4019 equality.  INCOMPATIBILITY.
  4020 
  4021 * Records. Removed K_record, and replaced it by pure lambda term
  4022 %x. c. The simplifier setup is now more robust against eta expansion.
  4023 INCOMPATIBILITY: in cases explicitly referring to K_record.
  4024 
  4025 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  4026 
  4027 * Library/ListVector: new theory of arithmetic vector operations.
  4028 
  4029 * Library/Order_Relation: new theory of various orderings as sets of
  4030 pairs.  Defines preorders, partial orders, linear orders and
  4031 well-orders on sets and on types.
  4032 
  4033 
  4034 *** ZF ***
  4035 
  4036 * Renamed some theories to allow to loading both ZF and HOL in the
  4037 same session:
  4038 
  4039   Datatype  -> Datatype_ZF
  4040   Inductive -> Inductive_ZF
  4041   Int       -> Int_ZF
  4042   IntDiv    -> IntDiv_ZF
  4043   Nat       -> Nat_ZF
  4044   List      -> List_ZF
  4045   Main      -> Main_ZF
  4046 
  4047 INCOMPATIBILITY: ZF theories that import individual theories below
  4048 Main might need to be adapted.  Regular theory Main is still
  4049 available, as trivial extension of Main_ZF.
  4050 
  4051 
  4052 *** ML ***
  4053 
  4054 * ML within Isar: antiquotation @{const name} or @{const
  4055 name(typargs)} produces statically-checked Const term.
  4056 
  4057 * Functor NamedThmsFun: data is available to the user as dynamic fact
  4058 (of the same name).  Removed obsolete print command.
  4059 
  4060 * Removed obsolete "use_legacy_bindings" function.
  4061 
  4062 * The ``print mode'' is now a thread-local value derived from a global
  4063 template (the former print_mode reference), thus access becomes
  4064 non-critical.  The global print_mode reference is for session
  4065 management only; user-code should use print_mode_value,
  4066 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  4067 
  4068 * Functions system/system_out provide a robust way to invoke external
  4069 shell commands, with propagation of interrupts (requires Poly/ML
  4070 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  4071 
  4072 
  4073 *** System ***
  4074 
  4075 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  4076 in accordance with Proof General 3.7, which prefers GNU emacs.
  4077 
  4078 * isatool tty runs Isabelle process with plain tty interaction;
  4079 optional line editor may be specified via ISABELLE_LINE_EDITOR
  4080 setting, the default settings attempt to locate "ledit" and "rlwrap".
  4081 
  4082 * isatool browser now works with Cygwin as well, using general
  4083 "javapath" function defined in Isabelle process environment.
  4084 
  4085 * YXML notation provides a simple and efficient alternative to
  4086 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  4087 isatool yxml as described in the Isabelle system manual.
  4088 
  4089 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  4090 provides general wrapper for managing an Isabelle process in a robust
  4091 fashion, with ``cooked'' output from stdin/stderr.
  4092 
  4093 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  4094 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  4095 
  4096 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  4097 way of changing the user's settings is via
  4098 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  4099 script.
  4100 
  4101 * Multithreading.max_threads := 0 refers to the number of actual CPU
  4102 cores of the underlying machine, which is a good starting point for
  4103 optimal performance tuning.  The corresponding usedir option -M allows
  4104 "max" as an alias for "0".  WARNING: does not work on certain versions
  4105 of Mac OS (with Poly/ML 5.1).
  4106 
  4107 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  4108 adverse effect of Isabelle flooding interactive front-ends (notably
  4109 ProofGeneral / XEmacs).
  4110 
  4111 
  4112 
  4113 New in Isabelle2007 (November 2007)
  4114 -----------------------------------
  4115 
  4116 *** General ***
  4117 
  4118 * More uniform information about legacy features, notably a
  4119 warning/error of "Legacy feature: ...", depending on the state of the
  4120 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  4121 legacy features will disappear eventually.
  4122 
  4123 * Theory syntax: the header format ``theory A = B + C:'' has been
  4124 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  4125 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  4126 
  4127 * Theory syntax: the old non-Isar theory file format has been
  4128 discontinued altogether.  Note that ML proof scripts may still be used
  4129 with Isar theories; migration is usually quite simple with the ML
  4130 function use_legacy_bindings.  INCOMPATIBILITY.
  4131 
  4132 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  4133 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  4134 quotes.
  4135 
  4136 * Theory loader: be more serious about observing the static theory
  4137 header specifications (including optional directories), but not the
  4138 accidental file locations of previously successful loads.  The strict
  4139 update policy of former update_thy is now already performed by
  4140 use_thy, so the former has been removed; use_thys updates several
  4141 theories simultaneously, just as 'imports' within a theory header
  4142 specification, but without merging the results.  Potential
  4143 INCOMPATIBILITY: may need to refine theory headers and commands
  4144 ROOT.ML which depend on load order.
  4145 
  4146 * Theory loader: optional support for content-based file
  4147 identification, instead of the traditional scheme of full physical
  4148 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  4149 (cf. the system manual).  The new scheme allows to work with
  4150 non-finished theories in persistent session images, such that source
  4151 files may be moved later on without requiring reloads.
  4152 
  4153 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4154 file (with the same base name as the theory) are considered a legacy
  4155 feature, which will disappear eventually. Even now, the theory loader
  4156 no longer maintains dependencies on such files.
  4157 
  4158 * Syntax: the scope for resolving ambiguities via type-inference is
  4159 now limited to individual terms, instead of whole simultaneous
  4160 specifications as before. This greatly reduces the complexity of the
  4161 syntax module and improves flexibility by separating parsing and
  4162 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  4163 'fixes' etc.) are required in rare situations.
  4164 
  4165 * Syntax: constants introduced by new-style packages ('definition',
  4166 'abbreviation' etc.) are passed through the syntax module in
  4167 ``authentic mode''. This means that associated mixfix annotations
  4168 really stick to such constants, independently of potential name space
  4169 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  4170 trees are represented slightly differently, may need to adapt syntax
  4171 translations accordingly. Use CONST marker in 'translations' and
  4172 @{const_syntax} antiquotation in 'parse_translation' etc.
  4173 
  4174 * Legacy goal package: reduced interface to the bare minimum required
  4175 to keep existing proof scripts running.  Most other user-level
  4176 functions are now part of the OldGoals structure, which is *not* open
  4177 by default (consider isatool expandshort before open OldGoals).
  4178 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  4179 these tend to cause confusion about the actual goal (!) context being
  4180 used here, which is not necessarily the same as the_context().
  4181 
  4182 * Command 'find_theorems': supports "*" wild-card in "name:"
  4183 criterion; "with_dups" option.  Certain ProofGeneral versions might
  4184 support a specific search form (see ProofGeneral/CHANGES).
  4185 
  4186 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  4187 by default, which means that "prems" (and also "fixed variables") are
  4188 suppressed from proof state output.  Note that the ProofGeneral
  4189 settings mechanism allows to change and save options persistently, but
  4190 older versions of Isabelle will fail to start up if a negative prems
  4191 limit is imposed.
  4192 
  4193 * Local theory targets may be specified by non-nested blocks of
  4194 ``context/locale/class ... begin'' followed by ``end''.  The body may
  4195 contain definitions, theorems etc., including any derived mechanism
  4196 that has been implemented on top of these primitives.  This concept
  4197 generalizes the existing ``theorem (in ...)'' towards more versatility
  4198 and scalability.
  4199 
  4200 * Proof General interface: proper undo of final 'end' command;
  4201 discontinued Isabelle/classic mode (ML proof scripts).
  4202 
  4203 
  4204 *** Document preparation ***
  4205 
  4206 * Added antiquotation @{theory name} which prints the given name,
  4207 after checking that it refers to a valid ancestor theory in the
  4208 current context.
  4209 
  4210 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  4211 check the given source text as ML type/structure, printing verbatim.
  4212 
  4213 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  4214 "c args == rhs" given in the current context.  (Any number of
  4215 arguments may be given on the LHS.)
  4216 
  4217 
  4218 *** Pure ***
  4219 
  4220 * The 'class' package offers a combination of axclass and locale to
  4221 achieve Haskell-like type classes in Isabelle.  Definitions and
  4222 theorems within a class context produce both relative results (with
  4223 implicit parameters according to the locale context), and polymorphic
  4224 constants with qualified polymorphism (according to the class
  4225 context).  Within the body context of a 'class' target, a separate
  4226 syntax layer ("user space type system") takes care of converting
  4227 between global polymorphic consts and internal locale representation.
  4228 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  4229 "isatool doc classes" provides a tutorial.
  4230 
  4231 * Generic code generator framework allows to generate executable
  4232 code for ML and Haskell (including Isabelle classes).  A short usage
  4233 sketch:
  4234 
  4235     internal compilation:
  4236         export_code <list of constants (term syntax)> in SML
  4237     writing SML code to a file:
  4238         export_code <list of constants (term syntax)> in SML <filename>
  4239     writing OCaml code to a file:
  4240         export_code <list of constants (term syntax)> in OCaml <filename>
  4241     writing Haskell code to a bunch of files:
  4242         export_code <list of constants (term syntax)> in Haskell <filename>
  4243 
  4244     evaluating closed propositions to True/False using code generation:
  4245         method ``eval''
  4246 
  4247 Reasonable default setup of framework in HOL.
  4248 
  4249 Theorem attributs for selecting and transforming function equations theorems:
  4250 
  4251     [code fun]:        select a theorem as function equation for a specific constant
  4252     [code fun del]:    deselect a theorem as function equation for a specific constant
  4253     [code inline]:     select an equation theorem for unfolding (inlining) in place
  4254     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  4255 
  4256 User-defined serializations (target in {SML, OCaml, Haskell}):
  4257 
  4258     code_const <and-list of constants (term syntax)>
  4259       {(target) <and-list of const target syntax>}+
  4260 
  4261     code_type <and-list of type constructors>
  4262       {(target) <and-list of type target syntax>}+
  4263 
  4264     code_instance <and-list of instances>
  4265       {(target)}+
  4266         where instance ::= <type constructor> :: <class>
  4267 
  4268     code_class <and_list of classes>
  4269       {(target) <and-list of class target syntax>}+
  4270         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  4271 
  4272 code_instance and code_class only are effective to target Haskell.
  4273 
  4274 For example usage see src/HOL/ex/Codegenerator.thy and
  4275 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  4276 generation from Isabelle/HOL theories is available via "isatool doc
  4277 codegen".
  4278 
  4279 * Code generator: consts in 'consts_code' Isar commands are now
  4280 referred to by usual term syntax (including optional type
  4281 annotations).
  4282 
  4283 * Command 'no_translations' removes translation rules from theory
  4284 syntax.
  4285 
  4286 * Overloaded definitions are now actually checked for acyclic
  4287 dependencies.  The overloading scheme is slightly more general than
  4288 that of Haskell98, although Isabelle does not demand an exact
  4289 correspondence to type class and instance declarations.
  4290 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4291 exotic versions of overloading -- at the discretion of the user!
  4292 
  4293 Polymorphic constants are represented via type arguments, i.e. the
  4294 instantiation that matches an instance against the most general
  4295 declaration given in the signature.  For example, with the declaration
  4296 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4297 as c(nat).  Overloading is essentially simultaneous structural
  4298 recursion over such type arguments.  Incomplete specification patterns
  4299 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4300 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4301 Command 'print_theory' outputs the normalized system of recursive
  4302 equations, see section "definitions".
  4303 
  4304 * Configuration options are maintained within the theory or proof
  4305 context (with name and type bool/int/string), providing a very simple
  4306 interface to a poor-man's version of general context data.  Tools may
  4307 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4308 these values using Config.get etc.  Users may change options via an
  4309 associated attribute of the same name.  This form of context
  4310 declaration works particularly well with commands 'declare' or
  4311 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4312 very easy to avoid global references, which would not observe Isar
  4313 toplevel undo/redo and fail to work with multithreading.
  4314 
  4315 Various global ML references of Pure and HOL have been turned into
  4316 configuration options:
  4317 
  4318   Unify.search_bound		unify_search_bound
  4319   Unify.trace_bound		unify_trace_bound
  4320   Unify.trace_simp		unify_trace_simp
  4321   Unify.trace_types		unify_trace_types
  4322   Simplifier.simp_depth_limit	simp_depth_limit
  4323   Blast.depth_limit		blast_depth_limit
  4324   DatatypeProp.dtK		datatype_distinctness_limit
  4325   fast_arith_neq_limit  	fast_arith_neq_limit
  4326   fast_arith_split_limit	fast_arith_split_limit
  4327 
  4328 * Named collections of theorems may be easily installed as context
  4329 data using the functor NamedThmsFun (see also
  4330 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4331 attributes; there is also a toplevel print command.  This facility is
  4332 just a common case of general context data, which is the preferred way
  4333 for anything more complex than just a list of facts in canonical
  4334 order.
  4335 
  4336 * Isar: command 'declaration' augments a local theory by generic
  4337 declaration functions written in ML.  This enables arbitrary content
  4338 being added to the context, depending on a morphism that tells the
  4339 difference of the original declaration context wrt. the application
  4340 context encountered later on.
  4341 
  4342 * Isar: proper interfaces for simplification procedures.  Command
  4343 'simproc_setup' declares named simprocs (with match patterns, and body
  4344 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4345 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4346 
  4347 * Isar: an extra pair of brackets around attribute declarations
  4348 abbreviates a theorem reference involving an internal dummy fact,
  4349 which will be ignored later --- only the effect of the attribute on
  4350 the background context will persist.  This form of in-place
  4351 declarations is particularly useful with commands like 'declare' and
  4352 'using', for example ``have A using [[simproc a]] by simp''.
  4353 
  4354 * Isar: method "assumption" (and implicit closing of subproofs) now
  4355 takes simple non-atomic goal assumptions into account: after applying
  4356 an assumption as a rule the resulting subgoals are solved by atomic
  4357 assumption steps.  This is particularly useful to finish 'obtain'
  4358 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4359 without referring to the original premise "!!x. P x ==> thesis" in the
  4360 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4361 more permissive.
  4362 
  4363 * Isar: implicit use of prems from the Isar proof context is
  4364 considered a legacy feature.  Common applications like ``have A .''
  4365 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4366 referencing facts explicitly here improves readability and
  4367 maintainability of proof texts.
  4368 
  4369 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4370 the obtained context from the course of reasoning!  For example:
  4371 
  4372   assume "EX x y. A x & B y"   -- "any previous fact"
  4373   then guess x and y by clarify
  4374 
  4375 This technique is potentially adventurous, depending on the facts and
  4376 proof tools being involved here.
  4377 
  4378 * Isar: known facts from the proof context may be specified as literal
  4379 propositions, using ASCII back-quote syntax.  This works wherever
  4380 named facts used to be allowed so far, in proof commands, proof
  4381 methods, attributes etc.  Literal facts are retrieved from the context
  4382 according to unification of type and term parameters.  For example,
  4383 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4384 theorems in the current context, then these are valid literal facts:
  4385 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4386 
  4387 There is also a proof method "fact" which does the same composition
  4388 for explicit goal states, e.g. the following proof texts coincide with
  4389 certain special cases of literal facts:
  4390 
  4391   have "A" by fact                 ==  note `A`
  4392   have "A ==> B" by fact           ==  note `A ==> B`
  4393   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4394   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4395 
  4396 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4397 outer syntax.  Thus symbolic identifiers may be used without
  4398 additional white space in declarations like this: ``assume *: A''.
  4399 
  4400 * Isar: 'print_facts' prints all local facts of the current context,
  4401 both named and unnamed ones.
  4402 
  4403 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4404 
  4405   def x == "t" and y == "u"
  4406 
  4407 * Isar: added command 'unfolding', which is structurally similar to
  4408 'using', but affects both the goal state and facts by unfolding given
  4409 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4410 'unfolded' attribute may be replaced by first-class proof text.
  4411 
  4412 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4413 and command 'unfolding' now all support object-level equalities
  4414 (potentially conditional).  The underlying notion of rewrite rule is
  4415 analogous to the 'rule_format' attribute, but *not* that of the
  4416 Simplifier (which is usually more generous).
  4417 
  4418 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4419 premises of a theorem by n. Useful in conjunction with drule.
  4420 
  4421 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4422 method expression within a sandbox consisting of the first N
  4423 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4424 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4425 simplifies all new goals that emerge from applying rule foo to the
  4426 originally first one.
  4427 
  4428 * Isar: schematic goals are no longer restricted to higher-order
  4429 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  4430 expected.
  4431 
  4432 * Isar: the conclusion of a long theorem statement is now either
  4433 'shows' (a simultaneous conjunction, as before), or 'obtains'
  4434 (essentially a disjunction of cases with local parameters and
  4435 assumptions).  The latter allows to express general elimination rules
  4436 adequately; in this notation common elimination rules look like this:
  4437 
  4438   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  4439     assumes "EX x. P x"
  4440     obtains x where "P x"
  4441 
  4442   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  4443     assumes "A & B"
  4444     obtains A and B
  4445 
  4446   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  4447     assumes "A | B"
  4448     obtains
  4449       A
  4450     | B
  4451 
  4452 The subsequent classical rules even refer to the formal "thesis"
  4453 explicitly:
  4454 
  4455   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  4456     obtains "~ thesis"
  4457 
  4458   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  4459     obtains "thesis ==> something"
  4460 
  4461 The actual proof of an 'obtains' statement is analogous to that of the
  4462 Isar proof element 'obtain', only that there may be several cases.
  4463 Optional case names may be specified in parentheses; these will be
  4464 available both in the present proof and as annotations in the
  4465 resulting rule, for later use with the 'cases' method (cf. attribute
  4466 case_names).
  4467 
  4468 * Isar: the assumptions of a long theorem statement are available as
  4469 "assms" fact in the proof context.  This is more appropriate than the
  4470 (historical) "prems", which refers to all assumptions of the current
  4471 context, including those from the target locale, proof body etc.
  4472 
  4473 * Isar: 'print_statement' prints theorems from the current theory or
  4474 proof context in long statement form, according to the syntax of a
  4475 top-level lemma.
  4476 
  4477 * Isar: 'obtain' takes an optional case name for the local context
  4478 introduction rule (default "that").
  4479 
  4480 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  4481 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  4482 to occur.
  4483 
  4484 * Pure: syntax "CONST name" produces a fully internalized constant
  4485 according to the current context.  This is particularly useful for
  4486 syntax translations that should refer to internal constant
  4487 representations independently of name spaces.
  4488 
  4489 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  4490 instead of "FOO ". This allows multiple binder declarations to coexist
  4491 in the same context.  INCOMPATIBILITY.
  4492 
  4493 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  4494 primitive that also works in a locale context (both for constants and
  4495 fixed variables). Type declaration and internal syntactic representation
  4496 of given constants retrieved from the context. Likewise, the
  4497 'no_notation' command allows to remove given syntax annotations from the
  4498 current context.
  4499 
  4500 * Isar/locales: new derived specification elements 'axiomatization',
  4501 'definition', 'abbreviation', which support type-inference, admit
  4502 object-level specifications (equality, equivalence).  See also the
  4503 isar-ref manual.  Examples:
  4504 
  4505   axiomatization
  4506     eq  (infix "===" 50) where
  4507     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  4508 
  4509   definition "f x y = x + y + 1"
  4510   definition g where "g x = f x x"
  4511 
  4512   abbreviation
  4513     neq  (infix "=!=" 50) where
  4514     "x =!= y == ~ (x === y)"
  4515 
  4516 These specifications may be also used in a locale context.  Then the
  4517 constants being introduced depend on certain fixed parameters, and the
  4518 constant name is qualified by the locale base name.  An internal
  4519 abbreviation takes care for convenient input and output, making the
  4520 parameters implicit and using the original short name.  See also
  4521 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  4522 entities from a monomorphic theory.
  4523 
  4524 Presently, abbreviations are only available 'in' a target locale, but
  4525 not inherited by general import expressions.  Also note that
  4526 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  4527 'translations' in common applications.  The "no_abbrevs" print mode
  4528 prevents folding of abbreviations in term output.
  4529 
  4530 Concrete syntax is attached to specified constants in internal form,
  4531 independently of name spaces.  The parse tree representation is
  4532 slightly different -- use 'notation' instead of raw 'syntax', and
  4533 'translations' with explicit "CONST" markup to accommodate this.
  4534 
  4535 * Pure/Isar: unified syntax for new-style specification mechanisms
  4536 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  4537 full type inference and dummy patterns ("_").  For example:
  4538 
  4539   definition "K x _ = x"
  4540 
  4541   inductive conj for A B
  4542   where "A ==> B ==> conj A B"
  4543 
  4544 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  4545 the current context.  Print mode "no_abbrevs" prevents inversion of
  4546 abbreviations on output.
  4547 
  4548 * Isar/locales: improved parameter handling: use of locales "var" and
  4549 "struct" no longer necessary; - parameter renamings are no longer
  4550 required to be injective.  For example, this allows to define
  4551 endomorphisms as locale endom = homom mult mult h.
  4552 
  4553 * Isar/locales: changed the way locales with predicates are defined.
  4554 Instead of accumulating the specification, the imported expression is
  4555 now an interpretation.  INCOMPATIBILITY: different normal form of
  4556 locale expressions.  In particular, in interpretations of locales with
  4557 predicates, goals repesenting already interpreted fragments are not
  4558 removed automatically.  Use methods `intro_locales' and
  4559 `unfold_locales'; see below.
  4560 
  4561 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  4562 provide backward reasoning on locales predicates.  The methods are
  4563 aware of interpretations and discharge corresponding goals.
  4564 `intro_locales' is less aggressive then `unfold_locales' and does not
  4565 unfold predicates to assumptions.
  4566 
  4567 * Isar/locales: the order in which locale fragments are accumulated
  4568 has changed.  This enables to override declarations from fragments due
  4569 to interpretations -- for example, unwanted simp rules.
  4570 
  4571 * Isar/locales: interpretation in theories and proof contexts has been
  4572 extended.  One may now specify (and prove) equations, which are
  4573 unfolded in interpreted theorems.  This is useful for replacing
  4574 defined concepts (constants depending on locale parameters) by
  4575 concepts already existing in the target context.  Example:
  4576 
  4577   interpretation partial_order ["op <= :: [int, int] => bool"]
  4578     where "partial_order.less (op <=) (x::int) y = (x < y)"
  4579 
  4580 Typically, the constant `partial_order.less' is created by a
  4581 definition specification element in the context of locale
  4582 partial_order.
  4583 
  4584 * Method "induct": improved internal context management to support
  4585 local fixes and defines on-the-fly. Thus explicit meta-level
  4586 connectives !!  and ==> are rarely required anymore in inductive goals
  4587 (using object-logic connectives for this purpose has been long
  4588 obsolete anyway). Common proof patterns are explained in
  4589 src/HOL/Induct/Common_Patterns.thy, see also
  4590 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  4591 examples.
  4592 
  4593 * Method "induct": improved handling of simultaneous goals. Instead of
  4594 introducing object-level conjunction, the statement is now split into
  4595 several conclusions, while the corresponding symbolic cases are nested
  4596 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  4597 see src/HOL/Induct/Common_Patterns.thy, for example.
  4598 
  4599 * Method "induct": mutual induction rules are now specified as a list
  4600 of rule sharing the same induction cases. HOL packages usually provide
  4601 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  4602 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  4603 mutual induction rules differently, i.e. like this:
  4604 
  4605   (induct rule: foo_bar.inducts)
  4606   (induct set: foo bar)
  4607   (induct pred: foo bar)
  4608   (induct type: foo bar)
  4609 
  4610 The ML function ProjectRule.projections turns old-style rules into the
  4611 new format.
  4612 
  4613 * Method "coinduct": dual of induction, see
  4614 src/HOL/Library/Coinductive_List.thy for various examples.
  4615 
  4616 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  4617 considered a legacy feature.
  4618 
  4619 * Attribute "symmetric" produces result with standardized schematic
  4620 variables (index 0).  Potential INCOMPATIBILITY.
  4621 
  4622 * Simplifier: by default the simplifier trace only shows top level
  4623 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  4624 default. Thus there is less danger of being flooded by the trace. The
  4625 trace indicates where parts have been suppressed.
  4626   
  4627 * Provers/classical: removed obsolete classical version of elim_format
  4628 attribute; classical elim/dest rules are now treated uniformly when
  4629 manipulating the claset.
  4630 
  4631 * Provers/classical: stricter checks to ensure that supplied intro,
  4632 dest and elim rules are well-formed; dest and elim rules must have at
  4633 least one premise.
  4634 
  4635 * Provers/classical: attributes dest/elim/intro take an optional
  4636 weight argument for the rule (just as the Pure versions).  Weights are
  4637 ignored by automated tools, but determine the search order of single
  4638 rule steps.
  4639 
  4640 * Syntax: input syntax now supports dummy variable binding "%_. b",
  4641 where the body does not mention the bound variable.  Note that dummy
  4642 patterns implicitly depend on their context of bounds, which makes
  4643 "{_. _}" match any set comprehension as expected.  Potential
  4644 INCOMPATIBILITY -- parse translations need to cope with syntactic
  4645 constant "_idtdummy" in the binding position.
  4646 
  4647 * Syntax: removed obsolete syntactic constant "_K" and its associated
  4648 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  4649 for example "A -> B" => "Pi A (%_. B)".
  4650 
  4651 * Pure: 'class_deps' command visualizes the subclass relation, using
  4652 the graph browser tool.
  4653 
  4654 * Pure: 'print_theory' now suppresses certain internal declarations by
  4655 default; use '!' option for full details.
  4656 
  4657 
  4658 *** HOL ***
  4659 
  4660 * Method "metis" proves goals by applying the Metis general-purpose
  4661 resolution prover (see also http://gilith.com/software/metis/).
  4662 Examples are in the directory MetisExamples.  WARNING: the
  4663 Isabelle/HOL-Metis integration does not yet work properly with
  4664 multi-threading.
  4665   
  4666 * Command 'sledgehammer' invokes external automatic theorem provers as
  4667 background processes.  It generates calls to the "metis" method if
  4668 successful. These can be pasted into the proof.  Users do not have to
  4669 wait for the automatic provers to return.  WARNING: does not really
  4670 work with multi-threading.
  4671 
  4672 * New "auto_quickcheck" feature tests outermost goal statements for
  4673 potential counter-examples.  Controlled by ML references
  4674 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  4675 5000 milliseconds).  Fails silently if statements is outside of
  4676 executable fragment, or any other codgenerator problem occurs.
  4677 
  4678 * New constant "undefined" with axiom "undefined x = undefined".
  4679 
  4680 * Added class "HOL.eq", allowing for code generation with polymorphic
  4681 equality.
  4682 
  4683 * Some renaming of class constants due to canonical name prefixing in
  4684 the new 'class' package:
  4685 
  4686     HOL.abs ~> HOL.abs_class.abs
  4687     HOL.divide ~> HOL.divide_class.divide
  4688     0 ~> HOL.zero_class.zero
  4689     1 ~> HOL.one_class.one
  4690     op + ~> HOL.plus_class.plus
  4691     op - ~> HOL.minus_class.minus
  4692     uminus ~> HOL.minus_class.uminus
  4693     op * ~> HOL.times_class.times
  4694     op < ~> HOL.ord_class.less
  4695     op <= > HOL.ord_class.less_eq
  4696     Nat.power ~> Power.power_class.power
  4697     Nat.size ~> Nat.size_class.size
  4698     Numeral.number_of ~> Numeral.number_class.number_of
  4699     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  4700     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  4701     Orderings.min ~> Orderings.ord_class.min
  4702     Orderings.max ~> Orderings.ord_class.max
  4703     Divides.op div ~> Divides.div_class.div
  4704     Divides.op mod ~> Divides.div_class.mod
  4705     Divides.op dvd ~> Divides.div_class.dvd
  4706 
  4707 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  4708 
  4709 a) User-defined constants using any of the names "plus", "minus",
  4710 "times", "less" or "less_eq". The standard syntax translations for
  4711 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  4712 names.
  4713 
  4714 b) Variables named "plus", "minus", "times", "less", "less_eq"
  4715 INCOMPATIBILITY: use more specific names.
  4716 
  4717 c) Permutative equations (e.g. "a + b = b + a")
  4718 Since the change of names also changes the order of terms, permutative
  4719 rewrite rules may get applied in a different order. Experience shows
  4720 that this is rarely the case (only two adaptions in the whole Isabelle
  4721 distribution).  INCOMPATIBILITY: rewrite proofs
  4722 
  4723 d) ML code directly refering to constant names
  4724 This in general only affects hand-written proof tactics, simprocs and
  4725 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  4726 Consider using @{const_name} antiquotation.
  4727 
  4728 * New class "default" with associated constant "default".
  4729 
  4730 * Function "sgn" is now overloaded and available on int, real, complex
  4731 (and other numeric types), using class "sgn".  Two possible defs of
  4732 sgn are given as equational assumptions in the classes sgn_if and
  4733 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  4734 INCOMPATIBILITY.
  4735 
  4736 * Locale "partial_order" now unified with class "order" (cf. theory
  4737 Orderings), added parameter "less".  INCOMPATIBILITY.
  4738 
  4739 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  4740 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  4741 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  4742 
  4743 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  4744 changed order of proof goals in instance proofs.
  4745 
  4746 * The transitivity reasoner for partial and linear orders is set up
  4747 for classes "order" and "linorder".  Instances of the reasoner are available
  4748 in all contexts importing or interpreting the corresponding locales.
  4749 Method "order" invokes the reasoner separately; the reasoner
  4750 is also integrated with the Simplifier as a solver.  Diagnostic
  4751 command 'print_orders' shows the available instances of the reasoner
  4752 in the current context.
  4753 
  4754 * Localized monotonicity predicate in theory "Orderings"; integrated
  4755 lemmas max_of_mono and min_of_mono with this predicate.
  4756 INCOMPATIBILITY.
  4757 
  4758 * Formulation of theorem "dense" changed slightly due to integration
  4759 with new class dense_linear_order.
  4760 
  4761 * Uniform lattice theory development in HOL.
  4762 
  4763     constants "meet" and "join" now named "inf" and "sup"
  4764     constant "Meet" now named "Inf"
  4765 
  4766     classes "meet_semilorder" and "join_semilorder" now named
  4767       "lower_semilattice" and "upper_semilattice"
  4768     class "lorder" now named "lattice"
  4769     class "comp_lat" now named "complete_lattice"
  4770 
  4771     Instantiation of lattice classes allows explicit definitions
  4772     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  4773 
  4774   INCOMPATIBILITY.  Theorem renames:
  4775 
  4776     meet_left_le            ~> inf_le1
  4777     meet_right_le           ~> inf_le2
  4778     join_left_le            ~> sup_ge1
  4779     join_right_le           ~> sup_ge2
  4780     meet_join_le            ~> inf_sup_ord
  4781     le_meetI                ~> le_infI
  4782     join_leI                ~> le_supI
  4783     le_meet                 ~> le_inf_iff
  4784     le_join                 ~> ge_sup_conv
  4785     meet_idempotent         ~> inf_idem
  4786     join_idempotent         ~> sup_idem
  4787     meet_comm               ~> inf_commute
  4788     join_comm               ~> sup_commute
  4789     meet_leI1               ~> le_infI1
  4790     meet_leI2               ~> le_infI2
  4791     le_joinI1               ~> le_supI1
  4792     le_joinI2               ~> le_supI2
  4793     meet_assoc              ~> inf_assoc
  4794     join_assoc              ~> sup_assoc
  4795     meet_left_comm          ~> inf_left_commute
  4796     meet_left_idempotent    ~> inf_left_idem
  4797     join_left_comm          ~> sup_left_commute
  4798     join_left_idempotent    ~> sup_left_idem
  4799     meet_aci                ~> inf_aci
  4800     join_aci                ~> sup_aci
  4801     le_def_meet             ~> le_iff_inf
  4802     le_def_join             ~> le_iff_sup
  4803     join_absorp2            ~> sup_absorb2
  4804     join_absorp1            ~> sup_absorb1
  4805     meet_absorp1            ~> inf_absorb1
  4806     meet_absorp2            ~> inf_absorb2
  4807     meet_join_absorp        ~> inf_sup_absorb
  4808     join_meet_absorp        ~> sup_inf_absorb
  4809     distrib_join_le         ~> distrib_sup_le
  4810     distrib_meet_le         ~> distrib_inf_le
  4811 
  4812     add_meet_distrib_left   ~> add_inf_distrib_left
  4813     add_join_distrib_left   ~> add_sup_distrib_left
  4814     is_join_neg_meet        ~> is_join_neg_inf
  4815     is_meet_neg_join        ~> is_meet_neg_sup
  4816     add_meet_distrib_right  ~> add_inf_distrib_right
  4817     add_join_distrib_right  ~> add_sup_distrib_right
  4818     add_meet_join_distribs  ~> add_sup_inf_distribs
  4819     join_eq_neg_meet        ~> sup_eq_neg_inf
  4820     meet_eq_neg_join        ~> inf_eq_neg_sup
  4821     add_eq_meet_join        ~> add_eq_inf_sup
  4822     meet_0_imp_0            ~> inf_0_imp_0
  4823     join_0_imp_0            ~> sup_0_imp_0
  4824     meet_0_eq_0             ~> inf_0_eq_0
  4825     join_0_eq_0             ~> sup_0_eq_0
  4826     neg_meet_eq_join        ~> neg_inf_eq_sup
  4827     neg_join_eq_meet        ~> neg_sup_eq_inf
  4828     join_eq_if              ~> sup_eq_if
  4829 
  4830     mono_meet               ~> mono_inf
  4831     mono_join               ~> mono_sup
  4832     meet_bool_eq            ~> inf_bool_eq
  4833     join_bool_eq            ~> sup_bool_eq
  4834     meet_fun_eq             ~> inf_fun_eq
  4835     join_fun_eq             ~> sup_fun_eq
  4836     meet_set_eq             ~> inf_set_eq
  4837     join_set_eq             ~> sup_set_eq
  4838     meet1_iff               ~> inf1_iff
  4839     meet2_iff               ~> inf2_iff
  4840     meet1I                  ~> inf1I
  4841     meet2I                  ~> inf2I
  4842     meet1D1                 ~> inf1D1
  4843     meet2D1                 ~> inf2D1
  4844     meet1D2                 ~> inf1D2
  4845     meet2D2                 ~> inf2D2
  4846     meet1E                  ~> inf1E
  4847     meet2E                  ~> inf2E
  4848     join1_iff               ~> sup1_iff
  4849     join2_iff               ~> sup2_iff
  4850     join1I1                 ~> sup1I1
  4851     join2I1                 ~> sup2I1
  4852     join1I1                 ~> sup1I1
  4853     join2I2                 ~> sup1I2
  4854     join1CI                 ~> sup1CI
  4855     join2CI                 ~> sup2CI
  4856     join1E                  ~> sup1E
  4857     join2E                  ~> sup2E
  4858 
  4859     is_meet_Meet            ~> is_meet_Inf
  4860     Meet_bool_def           ~> Inf_bool_def
  4861     Meet_fun_def            ~> Inf_fun_def
  4862     Meet_greatest           ~> Inf_greatest
  4863     Meet_lower              ~> Inf_lower
  4864     Meet_set_def            ~> Inf_set_def
  4865 
  4866     Sup_def                 ~> Sup_Inf
  4867     Sup_bool_eq             ~> Sup_bool_def
  4868     Sup_fun_eq              ~> Sup_fun_def
  4869     Sup_set_eq              ~> Sup_set_def
  4870 
  4871     listsp_meetI            ~> listsp_infI
  4872     listsp_meet_eq          ~> listsp_inf_eq
  4873 
  4874     meet_min                ~> inf_min
  4875     join_max                ~> sup_max
  4876 
  4877 * Added syntactic class "size"; overloaded constant "size" now has
  4878 type "'a::size ==> bool"
  4879 
  4880 * Internal reorganisation of `size' of datatypes: size theorems
  4881 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4882 simplification rules by default!); theorems "prod.size" now named
  4883 "*.size".
  4884 
  4885 * Class "div" now inherits from class "times" rather than "type".
  4886 INCOMPATIBILITY.
  4887 
  4888 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4889 Linorder etc.  have disappeared; operations defined in terms of
  4890 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4891 
  4892 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4893 
  4894 * HOL-Word: New extensive library and type for generic, fixed size
  4895 machine words, with arithmetic, bit-wise, shifting and rotating
  4896 operations, reflection into int, nat, and bool lists, automation for
  4897 linear arithmetic (by automatic reflection into nat or int), including
  4898 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4899 arithmetic type classes, supporting automatic simplification of
  4900 numerals on all operations.
  4901 
  4902 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4903 
  4904 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4905 
  4906 * Code generator library theories:
  4907   - Code_Integer represents HOL integers by big integer literals in target
  4908     languages.
  4909   - Code_Char represents HOL characters by character literals in target
  4910     languages.
  4911   - Code_Char_chr like Code_Char, but also offers treatment of character
  4912     codes; includes Code_Integer.
  4913   - Executable_Set allows to generate code for finite sets using lists.
  4914   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4915     denominator).
  4916   - Executable_Real implements a subset of real numbers, namly those
  4917     representable by rational numbers.
  4918   - Efficient_Nat implements natural numbers by integers, which in general will
  4919     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4920     includes Code_Integer.
  4921   - Code_Index provides an additional datatype index which is mapped to
  4922     target-language built-in integers.
  4923   - Code_Message provides an additional datatype message_string which is isomorphic to
  4924     strings; messages are mapped to target-language strings.
  4925 
  4926 * New package for inductive predicates
  4927 
  4928   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4929 
  4930     inductive
  4931       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4932       for z_1 :: U_1 and ... and z_n :: U_m
  4933     where
  4934       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4935     | ...
  4936 
  4937   with full support for type-inference, rather than
  4938 
  4939     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4940 
  4941     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4942     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4943 
  4944     inductive "s z_1 ... z_m"
  4945     intros
  4946       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4947       ...
  4948 
  4949   For backward compatibility, there is a wrapper allowing inductive
  4950   sets to be defined with the new package via
  4951 
  4952     inductive_set
  4953       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4954       for z_1 :: U_1 and ... and z_n :: U_m
  4955     where
  4956       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4957     | ...
  4958 
  4959   or
  4960 
  4961     inductive_set
  4962       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4963       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4964       for z_1 :: U_1 and ... and z_n :: U_m
  4965     where
  4966       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4967     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4968     | ...
  4969 
  4970   if the additional syntax "p ..." is required.
  4971 
  4972   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4973   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4974 
  4975   INCOMPATIBILITIES:
  4976 
  4977   - Since declaration and definition of inductive sets or predicates
  4978     is no longer separated, abbreviations involving the newly
  4979     introduced sets or predicates must be specified together with the
  4980     introduction rules after the 'where' keyword (see above), rather
  4981     than before the actual inductive definition.
  4982 
  4983   - The variables in induction and elimination rules are now
  4984     quantified in the order of their occurrence in the introduction
  4985     rules, rather than in alphabetical order. Since this may break
  4986     some proofs, these proofs either have to be repaired, e.g. by
  4987     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4988     statements of the form
  4989 
  4990       case (rule_i a_i_1 ... a_i_{k_i})
  4991 
  4992     or the old order of quantification has to be restored by explicitly adding
  4993     meta-level quantifiers in the introduction rules, i.e.
  4994 
  4995       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4996 
  4997   - The format of the elimination rules is now
  4998 
  4999       p z_1 ... z_m x_1 ... x_n ==>
  5000         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5001         ==> ... ==> P
  5002 
  5003     for predicates and
  5004 
  5005       (x_1, ..., x_n) : s z_1 ... z_m ==>
  5006         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  5007         ==> ... ==> P
  5008 
  5009     for sets rather than
  5010 
  5011       x : s z_1 ... z_m ==>
  5012         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  5013         ==> ... ==> P
  5014 
  5015     This may require terms in goals to be expanded to n-tuples
  5016     (e.g. using case_tac or simplification with the split_paired_all
  5017     rule) before the above elimination rule is applicable.
  5018 
  5019   - The elimination or case analysis rules for (mutually) inductive
  5020     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  5021     list of rules "p_1_..._p_k.elims" is no longer available.
  5022 
  5023 * New package "function"/"fun" for general recursive functions,
  5024 supporting mutual and nested recursion, definitions in local contexts,
  5025 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  5026 for small examples, and the separate tutorial on the function
  5027 package. The old recdef "package" is still available as before, but
  5028 users are encouraged to use the new package.
  5029 
  5030 * Method "lexicographic_order" automatically synthesizes termination
  5031 relations as lexicographic combinations of size measures. 
  5032 
  5033 * Case-expressions allow arbitrary constructor-patterns (including
  5034 "_") and take their order into account, like in functional
  5035 programming.  Internally, this is translated into nested
  5036 case-expressions; missing cases are added and mapped to the predefined
  5037 constant "undefined". In complicated cases printing may no longer show
  5038 the original input but the internal form. Lambda-abstractions allow
  5039 the same form of pattern matching: "% pat1 => e1 | ..." is an
  5040 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  5041 variable.
  5042 
  5043 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  5044 is an abbreviation for "of_nat :: nat => int". The simplification
  5045 rules for "of_nat" have been changed to work like "int" did
  5046 previously.  Potential INCOMPATIBILITY:
  5047   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  5048   - of_nat_diff and of_nat_mult are no longer default simp rules
  5049 
  5050 * Method "algebra" solves polynomial equations over (semi)rings using
  5051 Groebner bases. The (semi)ring structure is defined by locales and the
  5052 tool setup depends on that generic context. Installing the method for
  5053 a specific type involves instantiating the locale and possibly adding
  5054 declarations for computation on the coefficients.  The method is
  5055 already instantiated for natural numbers and for the axiomatic class
  5056 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  5057 CALCULEMUS 2007 for the general principles underlying this
  5058 architecture of context-aware proof-tools.
  5059 
  5060 * Method "ferrack" implements quantifier elimination over
  5061 special-purpose dense linear orders using locales (analogous to
  5062 "algebra"). The method is already installed for class
  5063 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  5064 rat, etc.
  5065 
  5066 * Former constant "List.op @" now named "List.append".  Use ML
  5067 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  5068 circumvent possible incompatibilities when working on ML level.
  5069 
  5070 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  5071 
  5072 * New function listsum :: 'a list => 'a for arbitrary monoids.
  5073 Special syntax: "SUM x <- xs. f x" (and latex variants)
  5074 
  5075 * New syntax for Haskell-like list comprehension (input only), eg.
  5076 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  5077 
  5078 * The special syntax for function "filter" has changed from [x :
  5079 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  5080 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  5081 
  5082 * [a..b] is now defined for arbitrary linear orders.  It used to be
  5083 defined on nat only, as an abbreviation for [a..<Suc b]
  5084 INCOMPATIBILITY.
  5085 
  5086 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  5087 
  5088 * New functions "sorted" and "sort" in src/HOL/List.thy.
  5089 
  5090 * New lemma collection field_simps (an extension of ring_simps) for
  5091 manipulating (in)equations involving division. Multiplies with all
  5092 denominators that can be proved to be non-zero (in equations) or
  5093 positive/negative (in inequations).
  5094 
  5095 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  5096 have been improved and renamed to ring_simps, group_simps and
  5097 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  5098 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  5099 
  5100 * Theory Library/Commutative_Ring: switched from recdef to function
  5101 package; constants add, mul, pow now curried.  Infix syntax for
  5102 algebraic operations.
  5103 
  5104 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  5105 INCOMPATIBILITY.
  5106 
  5107 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  5108 INCOMPATIBILITY.
  5109 
  5110 * HOL/records: generalised field-update to take a function on the
  5111 field rather than the new value: r(|A := x|) is translated to A_update
  5112 (K x) r The K-combinator that is internally used is called K_record.
  5113 INCOMPATIBILITY: Usage of the plain update functions has to be
  5114 adapted.
  5115  
  5116 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  5117 * x = 0, which are required for a semiring.  Richer structures do not
  5118 inherit from semiring_0 anymore, because this property is a theorem
  5119 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  5120 there is more to prove, but this is mostly trivial.
  5121 
  5122 * Class "recpower" is generalized to arbitrary monoids, not just
  5123 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  5124 commutativity or semiring properties additionally.
  5125 
  5126 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  5127 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  5128 better use 'abbreviation'.
  5129 
  5130 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  5131 
  5132 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  5133 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  5134 significant changes for setting up numeral syntax for types:
  5135   - New constants Numeral.pred and Numeral.succ instead
  5136       of former Numeral.bin_pred and Numeral.bin_succ.
  5137   - Use integer operations instead of bin_add, bin_mult and so on.
  5138   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  5139   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  5140 
  5141 See src/HOL/Integ/IntArith.thy for an example setup.
  5142 
  5143 * Command 'normal_form' computes the normal form of a term that may
  5144 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  5145 produces ``[b, c, a]'' (without proof).  This command is suitable for
  5146 heavy-duty computations because the functions are compiled to ML
  5147 first.  Correspondingly, a method "normalization" is provided.  See
  5148 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  5149 
  5150 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  5151 25 like -->); output depends on the "iff" print_mode, the default is
  5152 "A = B" (with priority 50).
  5153 
  5154 * Relations less (<) and less_eq (<=) are also available on type bool.
  5155 Modified syntax to disallow nesting without explicit parentheses,
  5156 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  5157 INCOMPATIBILITY.
  5158 
  5159 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  5160 
  5161 * Relation composition operator "op O" now has precedence 75 and binds
  5162 stronger than union and intersection. INCOMPATIBILITY.
  5163 
  5164 * The old set interval syntax "{m..n(}" (and relatives) has been
  5165 removed.  Use "{m..<n}" (and relatives) instead.
  5166 
  5167 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  5168 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  5169 ``declare [[simproc del: neq]]''.
  5170 
  5171 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  5172 True/False.
  5173 
  5174 * Theorem Cons_eq_map_conv no longer declared as "simp".
  5175 
  5176 * Theorem setsum_mult renamed to setsum_right_distrib.
  5177 
  5178 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  5179 ``rule'' method.
  5180 
  5181 * Reimplemented methods "sat" and "satx", with several improvements:
  5182 goals no longer need to be stated as "<prems> ==> False", equivalences
  5183 (i.e. "=" on type bool) are handled, variable names of the form
  5184 "lit_<n>" are no longer reserved, significant speedup.
  5185 
  5186 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  5187 zChaff is still supported as well.
  5188 
  5189 * 'inductive' and 'datatype': provide projections of mutual rules,
  5190 bundled as foo_bar.inducts;
  5191 
  5192 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  5193 Library.
  5194 
  5195 * Library: moved theory Accessible_Part to main HOL.
  5196 
  5197 * Library: added theory Coinductive_List of potentially infinite lists
  5198 as greatest fixed-point.
  5199 
  5200 * Library: added theory AssocList which implements (finite) maps as
  5201 association lists.
  5202 
  5203 * Method "evaluation" solves goals (i.e. a boolean expression)
  5204 efficiently by compiling it to ML.  The goal is "proved" (via an
  5205 oracle) if it evaluates to True.
  5206 
  5207 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  5208 also when invoked by the simplifier.  This results in the Simplifier
  5209 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  5210 Configuration option fast_arith_split_limit=0 recovers the old
  5211 behavior.
  5212 
  5213 * Support for hex (0x20) and binary (0b1001) numerals.
  5214 
  5215 * New method: reify eqs (t), where eqs are equations for an
  5216 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  5217 parameter, computes a term s::'b and a list xs::'a list and proves the
  5218 theorem I xs s = t. This is also known as reification or quoting. The
  5219 resulting theorem is applied to the subgoal to substitute t with I xs
  5220 s.  If t is omitted, the subgoal itself is reified.
  5221 
  5222 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  5223 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  5224 where f is supposed to be a computable function (in the sense of code
  5225 generattion). The method uses reify to compute s and xs as above then
  5226 applies corr_thm and uses normalization by evaluation to "prove" f s =
  5227 r and finally gets the theorem t = r, which is again applied to the
  5228 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  5229 
  5230 * Reflection: Automatic reification now handels binding, an example is
  5231 available in src/HOL/ex/ReflectionEx.thy
  5232 
  5233 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  5234 command 'statespace' that is similar to 'record', but introduces an
  5235 abstract specification based on the locale infrastructure instead of
  5236 HOL types.  This leads to extra flexibility in composing state spaces,
  5237 in particular multiple inheritance and renaming of components.
  5238 
  5239 
  5240 *** HOL-Complex ***
  5241 
  5242 * Hyperreal: Functions root and sqrt are now defined on negative real
  5243 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  5244 Nonnegativity side conditions have been removed from many lemmas, so
  5245 that more subgoals may now be solved by simplification; potential
  5246 INCOMPATIBILITY.
  5247 
  5248 * Real: new type classes formalize real normed vector spaces and
  5249 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  5250 and norm :: 'a => real.
  5251 
  5252 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  5253 reals into other types. The overloaded constant Reals :: 'a set is now
  5254 defined as range of_real; potential INCOMPATIBILITY.
  5255 
  5256 * Real: proper support for ML code generation, including 'quickcheck'.
  5257 Reals are implemented as arbitrary precision rationals.
  5258 
  5259 * Hyperreal: Several constants that previously worked only for the
  5260 reals have been generalized, so they now work over arbitrary vector
  5261 spaces. Type annotations may need to be added in some cases; potential
  5262 INCOMPATIBILITY.
  5263 
  5264   Infinitesimal  :: ('a::real_normed_vector) star set
  5265   HFinite        :: ('a::real_normed_vector) star set
  5266   HInfinite      :: ('a::real_normed_vector) star set
  5267   approx         :: ('a::real_normed_vector) star => 'a star => bool
  5268   monad          :: ('a::real_normed_vector) star => 'a star set
  5269   galaxy         :: ('a::real_normed_vector) star => 'a star set
  5270   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  5271   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  5272   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  5273   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  5274   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  5275   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  5276   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5277   sgn            :: 'a::real_normed_vector => 'a
  5278   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5279 
  5280 * Complex: Some complex-specific constants are now abbreviations for
  5281 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5282 hnorm.  Other constants have been entirely removed in favor of the
  5283 polymorphic versions (INCOMPATIBILITY):
  5284 
  5285   approx        <-- capprox
  5286   HFinite       <-- CFinite
  5287   HInfinite     <-- CInfinite
  5288   Infinitesimal <-- CInfinitesimal
  5289   monad         <-- cmonad
  5290   galaxy        <-- cgalaxy
  5291   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5292   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5293   (ns)deriv     <-- (ns)cderiv
  5294 
  5295 
  5296 *** HOL-Algebra ***
  5297 
  5298 * Formalisation of ideals and the quotient construction over rings.
  5299 
  5300 * Order and lattice theory no longer based on records.
  5301 INCOMPATIBILITY.
  5302 
  5303 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5304 greatest_closed.  INCOMPATIBILITY.
  5305 
  5306 * Method algebra is now set up via an attribute.  For examples see
  5307 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5308 of algebraic structures.
  5309 
  5310 * Renamed theory CRing to Ring.
  5311 
  5312 
  5313 *** HOL-Nominal ***
  5314 
  5315 * Substantial, yet incomplete support for nominal datatypes (binding
  5316 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5317 src/HOL/Nominal/Examples.  Prospective users should consult
  5318 http://isabelle.in.tum.de/nominal/
  5319 
  5320 
  5321 *** ML ***
  5322 
  5323 * ML basics: just one true type int, which coincides with IntInf.int
  5324 (even on SML/NJ).
  5325 
  5326 * ML within Isar: antiquotations allow to embed statically-checked
  5327 formal entities in the source, referring to the context available at
  5328 compile-time.  For example:
  5329 
  5330 ML {* @{sort "{zero,one}"} *}
  5331 ML {* @{typ "'a => 'b"} *}
  5332 ML {* @{term "%x. x"} *}
  5333 ML {* @{prop "x == y"} *}
  5334 ML {* @{ctyp "'a => 'b"} *}
  5335 ML {* @{cterm "%x. x"} *}
  5336 ML {* @{cprop "x == y"} *}
  5337 ML {* @{thm asm_rl} *}
  5338 ML {* @{thms asm_rl} *}
  5339 ML {* @{type_name c} *}
  5340 ML {* @{type_syntax c} *}
  5341 ML {* @{const_name c} *}
  5342 ML {* @{const_syntax c} *}
  5343 ML {* @{context} *}
  5344 ML {* @{theory} *}
  5345 ML {* @{theory Pure} *}
  5346 ML {* @{theory_ref} *}
  5347 ML {* @{theory_ref Pure} *}
  5348 ML {* @{simpset} *}
  5349 ML {* @{claset} *}
  5350 ML {* @{clasimpset} *}
  5351 
  5352 The same works for sources being ``used'' within an Isar context.
  5353 
  5354 * ML in Isar: improved error reporting; extra verbosity with
  5355 ML_Context.trace enabled.
  5356 
  5357 * Pure/General/table.ML: the join operations now works via exceptions
  5358 DUP/SAME instead of type option. This is simpler in simple cases, and
  5359 admits slightly more efficient complex applications.
  5360 
  5361 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5362 use Context.generic instead of just theory.
  5363 
  5364 * Pure: datatype Context.generic joins theory/Proof.context and
  5365 provides some facilities for code that works in either kind of
  5366 context, notably GenericDataFun for uniform theory and proof data.
  5367 
  5368 * Pure: simplified internal attribute type, which is now always
  5369 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5370 local (Proof.context) attributes have been discontinued, while
  5371 minimizing code duplication. Thm.rule_attribute and
  5372 Thm.declaration_attribute build canonical attributes; see also structure
  5373 Context for further operations on Context.generic, notably
  5374 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5375 declarations and definitions.
  5376 
  5377 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5378 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5379 init only required for impure data. INCOMPATIBILITY: empty really need
  5380 to be empty (no dependencies on theory content!)
  5381 
  5382 * Pure/kernel: consts certification ignores sort constraints given in
  5383 signature declarations. (This information is not relevant to the
  5384 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5385 potential INCOMPATIBILITY.
  5386 
  5387 * Pure: axiomatic type classes are now purely definitional, with
  5388 explicit proofs of class axioms and super class relations performed
  5389 internally. See Pure/axclass.ML for the main internal interfaces --
  5390 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5391 AxClass.axiomatize_class/classrel/arity supersede
  5392 Sign.add_classes/classrel/arities.
  5393 
  5394 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5395 global/local versions on theory vs. Proof.context have been
  5396 discontinued; Attrib.syntax and Method.syntax have been adapted
  5397 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5398 attributes, methods, etc.
  5399 
  5400 * Pure: several functions of signature "... -> theory -> theory * ..."
  5401 have been reoriented to "... -> theory -> ... * theory" in order to
  5402 allow natural usage in combination with the ||>, ||>>, |-> and
  5403 fold_map combinators.
  5404 
  5405 * Pure: official theorem names (closed derivations) and additional
  5406 comments (tags) are now strictly separate.  Name hints -- which are
  5407 maintained as tags -- may be attached any time without affecting the
  5408 derivation.
  5409 
  5410 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5411 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5412 achieve the old behaviour.
  5413 
  5414 * Pure: the "Goal" constant is now called "prop", supporting a
  5415 slightly more general idea of ``protecting'' meta-level rule
  5416 statements.
  5417 
  5418 * Pure: Logic.(un)varify only works in a global context, which is now
  5419 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5420 Logic.legacy_(un)varify as temporary workaround.
  5421 
  5422 * Pure: structure Name provides scalable operations for generating
  5423 internal variable names, notably Name.variants etc.  This replaces
  5424 some popular functions from term.ML:
  5425 
  5426   Term.variant		->  Name.variant
  5427   Term.variantlist	->  Name.variant_list
  5428   Term.invent_names	->  Name.invent_list
  5429 
  5430 Note that low-level renaming rarely occurs in new code -- operations
  5431 from structure Variable are used instead (see below).
  5432 
  5433 * Pure: structure Variable provides fundamental operations for proper
  5434 treatment of fixed/schematic variables in a context.  For example,
  5435 Variable.import introduces fixes for schematics of given facts and
  5436 Variable.export reverses the effect (up to renaming) -- this replaces
  5437 various freeze_thaw operations.
  5438 
  5439 * Pure: structure Goal provides simple interfaces for
  5440 init/conclude/finish and tactical prove operations (replacing former
  5441 Tactic.prove).  Goal.prove is the canonical way to prove results
  5442 within a given context; Goal.prove_global is a degraded version for
  5443 theory level goals, including a global Drule.standard.  Note that
  5444 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  5445 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  5446 in a locale context).
  5447 
  5448 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  5449 and type checking (Syntax.check_term etc.), with common combinations
  5450 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  5451 which are considered legacy and await removal.
  5452 
  5453 * Pure/Syntax: generic interfaces for type unchecking
  5454 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  5455 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  5456 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  5457 available for convenience, but refer to the very same operations using
  5458 a mere theory instead of a full context.
  5459 
  5460 * Isar: simplified treatment of user-level errors, using exception
  5461 ERROR of string uniformly.  Function error now merely raises ERROR,
  5462 without any side effect on output channels.  The Isar toplevel takes
  5463 care of proper display of ERROR exceptions.  ML code may use plain
  5464 handle/can/try; cat_error may be used to concatenate errors like this:
  5465 
  5466   ... handle ERROR msg => cat_error msg "..."
  5467 
  5468 Toplevel ML code (run directly or through the Isar toplevel) may be
  5469 embedded into the Isar toplevel with exception display/debug like
  5470 this:
  5471 
  5472   Isar.toplevel (fn () => ...)
  5473 
  5474 INCOMPATIBILITY, removed special transform_error facilities, removed
  5475 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  5476 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  5477 -- use plain ERROR instead.
  5478 
  5479 * Isar: theory setup now has type (theory -> theory), instead of a
  5480 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  5481 
  5482 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  5483 ProofContext.debug/verbose flags.
  5484 
  5485 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  5486 theory before entering a proof state.  Transactions now always see a
  5487 quasi-functional intermediate checkpoint, both in interactive and
  5488 batch mode.
  5489 
  5490 * Isar: simplified interfaces for outer syntax.  Renamed
  5491 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  5492 OuterSyntax.add_parsers -- this functionality is now included in
  5493 OuterSyntax.command etc.  INCOMPATIBILITY.
  5494 
  5495 * Simplifier: the simpset of a running simplification process now
  5496 contains a proof context (cf. Simplifier.the_context), which is the
  5497 very context that the initial simpset has been retrieved from (by
  5498 simpset_of/local_simpset_of).  Consequently, all plug-in components
  5499 (solver, looper etc.) may depend on arbitrary proof data.
  5500 
  5501 * Simplifier.inherit_context inherits the proof context (plus the
  5502 local bounds) of the current simplification process; any simproc
  5503 etc. that calls the Simplifier recursively should do this!  Removed
  5504 former Simplifier.inherit_bounds, which is already included here --
  5505 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  5506 specify an explicit context using Simplifier.context/theory_context.
  5507 
  5508 * Simplifier/Classical Reasoner: more abstract interfaces
  5509 change_simpset/claset for modifying the simpset/claset reference of a
  5510 theory; raw versions simpset/claset_ref etc. have been discontinued --
  5511 INCOMPATIBILITY.
  5512 
  5513 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  5514 "Trueprop" etc.
  5515 
  5516 
  5517 *** System ***
  5518 
  5519 * settings: the default heap location within ISABELLE_HOME_USER now
  5520 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  5521 Isabelle installations.
  5522 
  5523 * isabelle-process: option -S (secure mode) disables some critical
  5524 operations, notably runtime compilation and evaluation of ML source
  5525 code.
  5526 
  5527 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  5528 
  5529 * Support for parallel execution, using native multicore support of
  5530 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  5531 independent theories, according to the given theory header
  5532 specifications. The maximum number of worker threads is specified via
  5533 usedir option -M or the "max-threads" setting in Proof General. A
  5534 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  5535 to 6 on a 8-core machine.  User-code needs to observe certain
  5536 guidelines for thread-safe programming, see appendix A in the Isar
  5537 Implementation manual.
  5538 
  5539 
  5540 
  5541 New in Isabelle2005 (October 2005)
  5542 ----------------------------------
  5543 
  5544 *** General ***
  5545 
  5546 * Theory headers: the new header syntax for Isar theories is
  5547 
  5548   theory <name>
  5549   imports <theory1> ... <theoryN>
  5550   uses <file1> ... <fileM>
  5551   begin
  5552 
  5553 where the 'uses' part is optional.  The previous syntax
  5554 
  5555   theory <name> = <theory1> + ... + <theoryN>:
  5556 
  5557 will disappear in the next release.  Use isatool fixheaders to convert
  5558 existing theory files.  Note that there is no change in ancient
  5559 non-Isar theories now, but these will disappear soon.
  5560 
  5561 * Theory loader: parent theories can now also be referred to via
  5562 relative and absolute paths.
  5563 
  5564 * Command 'find_theorems' searches for a list of criteria instead of a
  5565 list of constants. Known criteria are: intro, elim, dest, name:string,
  5566 simp:term, and any term. Criteria can be preceded by '-' to select
  5567 theorems that do not match. Intro, elim, dest select theorems that
  5568 match the current goal, name:s selects theorems whose fully qualified
  5569 name contain s, and simp:term selects all simplification rules whose
  5570 lhs match term.  Any other term is interpreted as pattern and selects
  5571 all theorems matching the pattern. Available in ProofGeneral under
  5572 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  5573 
  5574   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  5575 
  5576 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  5577 matching the current goal as introduction rule and not having "HOL."
  5578 in their name (i.e. not being defined in theory HOL).
  5579 
  5580 * Command 'thms_containing' has been discontinued in favour of
  5581 'find_theorems'; INCOMPATIBILITY.
  5582 
  5583 * Communication with Proof General is now 8bit clean, which means that
  5584 Unicode text in UTF-8 encoding may be used within theory texts (both
  5585 formal and informal parts).  Cf. option -U of the Isabelle Proof
  5586 General interface.  Here are some simple examples (cf. src/HOL/ex):
  5587 
  5588   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  5589   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  5590 
  5591 * Improved efficiency of the Simplifier and, to a lesser degree, the
  5592 Classical Reasoner.  Typical big applications run around 2 times
  5593 faster.
  5594 
  5595 
  5596 *** Document preparation ***
  5597 
  5598 * Commands 'display_drafts' and 'print_drafts' perform simple output
  5599 of raw sources.  Only those symbols that do not require additional
  5600 LaTeX packages (depending on comments in isabellesym.sty) are
  5601 displayed properly, everything else is left verbatim.  isatool display
  5602 and isatool print are used as front ends (these are subject to the
  5603 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  5604 
  5605 * Command tags control specific markup of certain regions of text,
  5606 notably folding and hiding.  Predefined tags include "theory" (for
  5607 theory begin and end), "proof" for proof commands, and "ML" for
  5608 commands involving ML code; the additional tags "visible" and
  5609 "invisible" are unused by default.  Users may give explicit tag
  5610 specifications in the text, e.g. ''by %invisible (auto)''.  The
  5611 interpretation of tags is determined by the LaTeX job during document
  5612 preparation: see option -V of isatool usedir, or options -n and -t of
  5613 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  5614 \isadroptag.
  5615 
  5616 Several document versions may be produced at the same time via isatool
  5617 usedir (the generated index.html will link all of them).  Typical
  5618 specifications include ''-V document=theory,proof,ML'' to present
  5619 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  5620 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  5621 these parts without any formal replacement text.  The Isabelle site
  5622 default settings produce ''document'' and ''outline'' versions as
  5623 specified above.
  5624 
  5625 * Several new antiquotations:
  5626 
  5627   @{term_type term} prints a term with its type annotated;
  5628 
  5629   @{typeof term} prints the type of a term;
  5630 
  5631   @{const const} is the same as @{term const}, but checks that the
  5632   argument is a known logical constant;
  5633 
  5634   @{term_style style term} and @{thm_style style thm} print a term or
  5635   theorem applying a "style" to it
  5636 
  5637   @{ML text}
  5638 
  5639 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  5640 definitions, equations, inequations etc., 'concl' printing only the
  5641 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  5642 to print the specified premise.  TermStyle.add_style provides an ML
  5643 interface for introducing further styles.  See also the "LaTeX Sugar"
  5644 document practical applications.  The ML antiquotation prints
  5645 type-checked ML expressions verbatim.
  5646 
  5647 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  5648 and 'text' support optional locale specification '(in loc)', which
  5649 specifies the default context for interpreting antiquotations.  For
  5650 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  5651 
  5652 * Option 'locale=NAME' of antiquotations specifies an alternative
  5653 context interpreting the subsequent argument.  For example: @{thm
  5654 [locale=lattice] inf_assoc}.
  5655 
  5656 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  5657 a proof context.
  5658 
  5659 * Proper output of antiquotations for theory commands involving a
  5660 proof context (such as 'locale' or 'theorem (in loc) ...').
  5661 
  5662 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  5663 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  5664 
  5665 * isatool usedir: new option -C (default true) controls whether option
  5666 -D should include a copy of the original document directory; -C false
  5667 prevents unwanted effects such as copying of administrative CVS data.
  5668 
  5669 
  5670 *** Pure ***
  5671 
  5672 * Considerably improved version of 'constdefs' command.  Now performs
  5673 automatic type-inference of declared constants; additional support for
  5674 local structure declarations (cf. locales and HOL records), see also
  5675 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  5676 sequential dependencies of definitions within a single 'constdefs'
  5677 section; moreover, the declared name needs to be an identifier.  If
  5678 all fails, consider to fall back on 'consts' and 'defs' separately.
  5679 
  5680 * Improved indexed syntax and implicit structures.  First of all,
  5681 indexed syntax provides a notational device for subscripted
  5682 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  5683 expressions.  Secondly, in a local context with structure
  5684 declarations, number indexes \<^sub>n or the empty index (default
  5685 number 1) refer to a certain fixed variable implicitly; option
  5686 show_structs controls printing of implicit structures.  Typical
  5687 applications of these concepts involve record types and locales.
  5688 
  5689 * New command 'no_syntax' removes grammar declarations (and
  5690 translations) resulting from the given syntax specification, which is
  5691 interpreted in the same manner as for the 'syntax' command.
  5692 
  5693 * 'Advanced' translation functions (parse_translation etc.) may depend
  5694 on the signature of the theory context being presently used for
  5695 parsing/printing, see also isar-ref manual.
  5696 
  5697 * Improved 'oracle' command provides a type-safe interface to turn an
  5698 ML expression of type theory -> T -> term into a primitive rule of
  5699 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  5700 is already included here); see also FOL/ex/IffExample.thy;
  5701 INCOMPATIBILITY.
  5702 
  5703 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  5704 before); "cI" is no longer bound, use "c.intro" instead.
  5705 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  5706 axclasses vs. locales.
  5707 
  5708 * Improved internal renaming of symbolic identifiers -- attach primes
  5709 instead of base 26 numbers.
  5710 
  5711 * New flag show_question_marks controls printing of leading question
  5712 marks in schematic variable names.
  5713 
  5714 * In schematic variable names, *any* symbol following \<^isub> or
  5715 \<^isup> is now treated as part of the base name.  For example, the
  5716 following works without printing of awkward ".0" indexes:
  5717 
  5718   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  5719     by simp
  5720 
  5721 * Inner syntax includes (*(*nested*) comments*).
  5722 
  5723 * Pretty printer now supports unbreakable blocks, specified in mixfix
  5724 annotations as "(00...)".
  5725 
  5726 * Clear separation of logical types and nonterminals, where the latter
  5727 may only occur in 'syntax' specifications or type abbreviations.
  5728 Before that distinction was only partially implemented via type class
  5729 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  5730 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  5731 exotic syntax specifications may require further adaption
  5732 (e.g. Cube/Cube.thy).
  5733 
  5734 * Removed obsolete type class "logic", use the top sort {} instead.
  5735 Note that non-logical types should be declared as 'nonterminals'
  5736 rather than 'types'.  INCOMPATIBILITY for new object-logic
  5737 specifications.
  5738 
  5739 * Attributes 'induct' and 'cases': type or set names may now be
  5740 locally fixed variables as well.
  5741 
  5742 * Simplifier: can now control the depth to which conditional rewriting
  5743 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  5744 Limit.
  5745 
  5746 * Simplifier: simplification procedures may now take the current
  5747 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  5748 interface), which is very useful for calling the Simplifier
  5749 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  5750 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  5751 low-level mk_simproc no longer applies Logic.varify internally, to
  5752 allow for use in a context of fixed variables.
  5753 
  5754 * thin_tac now works even if the assumption being deleted contains !!
  5755 or ==>.  More generally, erule now works even if the major premise of
  5756 the elimination rule contains !! or ==>.
  5757 
  5758 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  5759 
  5760 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  5761 from Pure, which contains all common declarations already.  Both
  5762 theories are defined via plain Isabelle/Isar .thy files.
  5763 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  5764 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  5765 use isatool fixcpure to adapt your theory and ML sources.
  5766 
  5767 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  5768 selections of theorems in named facts via index ranges.
  5769 
  5770 * 'print_theorems': in theory mode, really print the difference
  5771 wrt. the last state (works for interactive theory development only),
  5772 in proof mode print all local facts (cf. 'print_facts');
  5773 
  5774 * 'hide': option '(open)' hides only base names.
  5775 
  5776 * More efficient treatment of intermediate checkpoints in interactive
  5777 theory development.
  5778 
  5779 * Code generator is now invoked via code_module (incremental code
  5780 generation) and code_library (modular code generation, ML structures
  5781 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  5782 must be quoted when used as identifiers.
  5783 
  5784 * New 'value' command for reading, evaluating and printing terms using
  5785 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  5786 quoted when used as identifier.
  5787 
  5788 
  5789 *** Locales ***
  5790 
  5791 * New commands for the interpretation of locale expressions in
  5792 theories (1), locales (2) and proof contexts (3).  These generate
  5793 proof obligations from the expression specification.  After the
  5794 obligations have been discharged, theorems of the expression are added
  5795 to the theory, target locale or proof context.  The synopsis of the
  5796 commands is a follows:
  5797 
  5798   (1) interpretation expr inst
  5799   (2) interpretation target < expr
  5800   (3) interpret expr inst
  5801 
  5802 Interpretation in theories and proof contexts require a parameter
  5803 instantiation of terms from the current context.  This is applied to
  5804 specifications and theorems of the interpreted expression.
  5805 Interpretation in locales only permits parameter renaming through the
  5806 locale expression.  Interpretation is smart in that interpretations
  5807 that are active already do not occur in proof obligations, neither are
  5808 instantiated theorems stored in duplicate.  Use 'print_interps' to
  5809 inspect active interpretations of a particular locale.  For details,
  5810 see the Isar Reference manual.  Examples can be found in
  5811 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  5812 
  5813 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  5814 'interpret' instead.
  5815 
  5816 * New context element 'constrains' for adding type constraints to
  5817 parameters.
  5818 
  5819 * Context expressions: renaming of parameters with syntax
  5820 redeclaration.
  5821 
  5822 * Locale declaration: 'includes' disallowed.
  5823 
  5824 * Proper static binding of attribute syntax -- i.e. types / terms /
  5825 facts mentioned as arguments are always those of the locale definition
  5826 context, independently of the context of later invocations.  Moreover,
  5827 locale operations (renaming and type / term instantiation) are applied
  5828 to attribute arguments as expected.
  5829 
  5830 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5831 actual attributes; rare situations may require Attrib.attribute to
  5832 embed those attributes into Attrib.src that lack concrete syntax.
  5833 Attribute implementations need to cooperate properly with the static
  5834 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5835 Attrib.XXX_thm etc. already do the right thing without further
  5836 intervention.  Only unusual applications -- such as "where" or "of"
  5837 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5838 on the context and the facts involved -- may have to assign parsed
  5839 values to argument tokens explicitly.
  5840 
  5841 * Changed parameter management in theorem generation for long goal
  5842 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5843 theorem statement in rare situations.
  5844 
  5845 * Locale inspection command 'print_locale' omits notes elements.  Use
  5846 'print_locale!' to have them included in the output.
  5847 
  5848 
  5849 *** Provers ***
  5850 
  5851 * Provers/hypsubst.ML: improved version of the subst method, for
  5852 single-step rewriting: it now works in bound variable contexts. New is
  5853 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5854 rewrite a different subterm than the original subst method, which is
  5855 still available as 'simplesubst'.
  5856 
  5857 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5858 and quasi orders.
  5859 
  5860 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5861 reflexive-transitive closure of relations.
  5862 
  5863 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5864 limit (previously hard-coded with a value of 20) user-definable.
  5865 
  5866 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5867 is peformed already.  Object-logics merely need to finish their
  5868 initial simpset configuration as before.  INCOMPATIBILITY.
  5869 
  5870 
  5871 *** HOL ***
  5872 
  5873 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5874 
  5875   syntax (epsilon)
  5876     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5877 
  5878 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5879 and x-symbol; use option '-m epsilon' to get it actually printed.
  5880 Moreover, the mathematically important symbolic identifier \<epsilon>
  5881 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5882 
  5883 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5884 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5885 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5886 support corresponding Isar calculations.
  5887 
  5888 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5889 instead of ":".
  5890 
  5891 * theory SetInterval: changed the syntax for open intervals:
  5892 
  5893   Old       New
  5894   {..n(}    {..<n}
  5895   {)n..}    {n<..}
  5896   {m..n(}   {m..<n}
  5897   {)m..n}   {m<..n}
  5898   {)m..n(}  {m<..<n}
  5899 
  5900 The old syntax is still supported but will disappear in the next
  5901 release.  For conversion use the following Emacs search and replace
  5902 patterns (these are not perfect but work quite well):
  5903 
  5904   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5905   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5906 
  5907 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5908 equalities in commutative rings; method 'algebra' provides a generic
  5909 interface.
  5910 
  5911 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5912 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5913 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5914 be a tuple pattern.
  5915 
  5916 Some new syntax forms are available:
  5917 
  5918   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5919   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5920   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5921   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5922 
  5923 The latter form "\<Sum>x < k. e" used to be based on a separate
  5924 function "Summation", which has been discontinued.
  5925 
  5926 * theory Finite_Set: in structured induction proofs, the insert case
  5927 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5928 (insert F x)'.
  5929 
  5930 * The 'refute' command has been extended to support a much larger
  5931 fragment of HOL, including axiomatic type classes, constdefs and
  5932 typedefs, inductive datatypes and recursion.
  5933 
  5934 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5935 Requires zChaff with proof generation to be installed.  See
  5936 HOL/ex/SAT_Examples.thy for examples.
  5937 
  5938 * Datatype induction via method 'induct' now preserves the name of the
  5939 induction variable. For example, when proving P(xs::'a list) by
  5940 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5941 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5942 in unstructured proof scripts.
  5943 
  5944 * Reworked implementation of records.  Improved scalability for
  5945 records with many fields, avoiding performance problems for type
  5946 inference. Records are no longer composed of nested field types, but
  5947 of nested extension types. Therefore the record type only grows linear
  5948 in the number of extensions and not in the number of fields.  The
  5949 top-level (users) view on records is preserved.  Potential
  5950 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5951 old record representation. The type generated for a record is called
  5952 <record_name>_ext_type.
  5953 
  5954 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5955 proofs triggered by a record definition or a simproc (if
  5956 quick_and_dirty is enabled).  Definitions of large records can take
  5957 quite long.
  5958 
  5959 New simproc record_upd_simproc for simplification of multiple record
  5960 updates enabled by default.  Moreover, trivial updates are also
  5961 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5962 occasionally, since simplification is more powerful by default.
  5963 
  5964 * typedef: proper support for polymorphic sets, which contain extra
  5965 type-variables in the term.
  5966 
  5967 * Simplifier: automatically reasons about transitivity chains
  5968 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5969 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5970 old proofs break occasionally as simplification may now solve more
  5971 goals than previously.
  5972 
  5973 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5974 present.  Works for all partial orders (class "order"), in particular
  5975 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5976 just like y <= x.
  5977 
  5978 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5979 bound variable or a constant then the let is unfolded.  Otherwise
  5980 first a is simplified to b, and then f b is simplified to g. If
  5981 possible we abstract b from g arriving at "let x = b in h x",
  5982 otherwise we unfold the let and arrive at g.  The simproc can be
  5983 enabled/disabled by the reference use_let_simproc.  Potential
  5984 INCOMPATIBILITY since simplification is more powerful by default.
  5985 
  5986 * Classical reasoning: the meson method now accepts theorems as arguments.
  5987 
  5988 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5989 jobs to provide advice on the provability of subgoals.
  5990 
  5991 * Theory OrderedGroup and Ring_and_Field: various additions and
  5992 improvements to faciliate calculations involving equalities and
  5993 inequalities.
  5994 
  5995 The following theorems have been eliminated or modified
  5996 (INCOMPATIBILITY):
  5997 
  5998   abs_eq             now named abs_of_nonneg
  5999   abs_of_ge_0        now named abs_of_nonneg
  6000   abs_minus_eq       now named abs_of_nonpos
  6001   imp_abs_id         now named abs_of_nonneg
  6002   imp_abs_neg_id     now named abs_of_nonpos
  6003   mult_pos           now named mult_pos_pos
  6004   mult_pos_le        now named mult_nonneg_nonneg
  6005   mult_pos_neg_le    now named mult_nonneg_nonpos
  6006   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  6007   mult_neg           now named mult_neg_neg
  6008   mult_neg_le        now named mult_nonpos_nonpos
  6009 
  6010 * The following lemmas in Ring_and_Field have been added to the simplifier:
  6011      
  6012      zero_le_square
  6013      not_square_less_zero 
  6014 
  6015   The following lemmas have been deleted from Real/RealPow:
  6016   
  6017      realpow_zero_zero
  6018      realpow_two
  6019      realpow_less
  6020      zero_le_power
  6021      realpow_two_le
  6022      abs_realpow_two
  6023      realpow_two_abs     
  6024 
  6025 * Theory Parity: added rules for simplifying exponents.
  6026 
  6027 * Theory List:
  6028 
  6029 The following theorems have been eliminated or modified
  6030 (INCOMPATIBILITY):
  6031 
  6032   list_all_Nil       now named list_all.simps(1)
  6033   list_all_Cons      now named list_all.simps(2)
  6034   list_all_conv      now named list_all_iff
  6035   set_mem_eq         now named mem_iff
  6036 
  6037 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  6038 asymptotic "big O" calculations.  See the notes in BigO.thy.
  6039 
  6040 
  6041 *** HOL-Complex ***
  6042 
  6043 * Theory RealDef: better support for embedding natural numbers and
  6044 integers in the reals.
  6045 
  6046 The following theorems have been eliminated or modified
  6047 (INCOMPATIBILITY):
  6048 
  6049   exp_ge_add_one_self  now requires no hypotheses
  6050   real_of_int_add      reversed direction of equality (use [symmetric])
  6051   real_of_int_minus    reversed direction of equality (use [symmetric])
  6052   real_of_int_diff     reversed direction of equality (use [symmetric])
  6053   real_of_int_mult     reversed direction of equality (use [symmetric])
  6054 
  6055 * Theory RComplete: expanded support for floor and ceiling functions.
  6056 
  6057 * Theory Ln is new, with properties of the natural logarithm
  6058 
  6059 * Hyperreal: There is a new type constructor "star" for making
  6060 nonstandard types.  The old type names are now type synonyms:
  6061 
  6062   hypreal = real star
  6063   hypnat = nat star
  6064   hcomplex = complex star
  6065 
  6066 * Hyperreal: Many groups of similarly-defined constants have been
  6067 replaced by polymorphic versions (INCOMPATIBILITY):
  6068 
  6069   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  6070 
  6071   starset      <-- starsetNat, starsetC
  6072   *s*          <-- *sNat*, *sc*
  6073   starset_n    <-- starsetNat_n, starsetC_n
  6074   *sn*         <-- *sNatn*, *scn*
  6075   InternalSets <-- InternalNatSets, InternalCSets
  6076 
  6077   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  6078   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  6079   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  6080   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  6081   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  6082 
  6083 * Hyperreal: Many type-specific theorems have been removed in favor of
  6084 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  6085 
  6086   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  6087   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  6088   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  6089   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  6090   right_minus <-- hypreal_add_minus
  6091   left_minus <-- {hypreal,hcomplex}_add_minus_left
  6092   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  6093   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  6094   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  6095   mult_1_right <-- hcomplex_mult_one_right
  6096   mult_zero_left <-- hcomplex_mult_zero_left
  6097   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  6098   right_distrib <-- hypnat_add_mult_distrib2
  6099   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  6100   right_inverse <-- hypreal_mult_inverse
  6101   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  6102   order_refl <-- {hypreal,hypnat}_le_refl
  6103   order_trans <-- {hypreal,hypnat}_le_trans
  6104   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  6105   order_less_le <-- {hypreal,hypnat}_less_le
  6106   linorder_linear <-- {hypreal,hypnat}_le_linear
  6107   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  6108   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  6109   add_nonneg_nonneg <-- hypreal_le_add_order
  6110 
  6111 * Hyperreal: Separate theorems having to do with type-specific
  6112 versions of constants have been merged into theorems that apply to the
  6113 new polymorphic constants (INCOMPATIBILITY):
  6114 
  6115   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  6116   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  6117   STAR_Un <-- {STAR,NatStar,STARC}_Un
  6118   STAR_Int <-- {STAR,NatStar,STARC}_Int
  6119   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  6120   STAR_subset <-- {STAR,NatStar,STARC}_subset
  6121   STAR_mem <-- {STAR,NatStar,STARC}_mem
  6122   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  6123   STAR_diff <-- {STAR,STARC}_diff
  6124   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  6125     STARC_hcomplex_of_complex}_image_subset
  6126   starset_n_Un <-- starset{Nat,C}_n_Un
  6127   starset_n_Int <-- starset{Nat,C}_n_Int
  6128   starset_n_Compl <-- starset{Nat,C}_n_Compl
  6129   starset_n_diff <-- starset{Nat,C}_n_diff
  6130   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  6131   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  6132   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  6133   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  6134   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  6135   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  6136   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  6137   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  6138   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  6139   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  6140   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  6141   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  6142   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  6143   starfun_diff <-- starfun{C,RC,CR}_diff
  6144   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  6145   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  6146   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  6147   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  6148   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  6149   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  6150   starfun_Id <-- starfunC_Id
  6151   starfun_approx <-- starfun{Nat,CR}_approx
  6152   starfun_capprox <-- starfun{C,RC}_capprox
  6153   starfun_abs <-- starfunNat_rabs
  6154   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  6155   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  6156   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  6157   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  6158   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  6159   starfun_add_approx <-- starfunCR_add_approx
  6160   starfun_inverse_inverse <-- starfunC_inverse_inverse
  6161   starfun_divide <-- starfun{C,CR,RC}_divide
  6162   starfun_n <-- starfun{Nat,C}_n
  6163   starfun_n_mult <-- starfun{Nat,C}_n_mult
  6164   starfun_n_add <-- starfun{Nat,C}_n_add
  6165   starfun_n_add_minus <-- starfunNat_n_add_minus
  6166   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  6167   starfun_n_minus <-- starfun{Nat,C}_n_minus
  6168   starfun_n_eq <-- starfun{Nat,C}_n_eq
  6169 
  6170   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  6171   star_n_minus <-- {hypreal,hcomplex}_minus
  6172   star_n_diff <-- {hypreal,hcomplex}_diff
  6173   star_n_mult <-- {hypreal,hcomplex}_mult
  6174   star_n_inverse <-- {hypreal,hcomplex}_inverse
  6175   star_n_le <-- {hypreal,hypnat}_le
  6176   star_n_less <-- {hypreal,hypnat}_less
  6177   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  6178   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  6179   star_n_abs <-- hypreal_hrabs
  6180   star_n_divide <-- hcomplex_divide
  6181 
  6182   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  6183   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  6184   star_of_diff <-- hypreal_of_real_diff
  6185   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  6186   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  6187   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  6188   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  6189   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  6190   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  6191   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  6192   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  6193   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  6194   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  6195   star_of_number_of <-- {hypreal,hcomplex}_number_of
  6196   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  6197   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  6198   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  6199   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  6200   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  6201   star_of_power <-- hypreal_of_real_power
  6202   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  6203 
  6204 * Hyperreal: new method "transfer" that implements the transfer
  6205 principle of nonstandard analysis. With a subgoal that mentions
  6206 nonstandard types like "'a star", the command "apply transfer"
  6207 replaces it with an equivalent one that mentions only standard types.
  6208 To be successful, all free variables must have standard types; non-
  6209 standard variables must have explicit universal quantifiers.
  6210 
  6211 * Hyperreal: A theory of Taylor series.
  6212 
  6213 
  6214 *** HOLCF ***
  6215 
  6216 * Discontinued special version of 'constdefs' (which used to support
  6217 continuous functions) in favor of the general Pure one with full
  6218 type-inference.
  6219 
  6220 * New simplification procedure for solving continuity conditions; it
  6221 is much faster on terms with many nested lambda abstractions (cubic
  6222 instead of exponential time).
  6223 
  6224 * New syntax for domain package: selector names are now optional.
  6225 Parentheses should be omitted unless argument is lazy, for example:
  6226 
  6227   domain 'a stream = cons "'a" (lazy "'a stream")
  6228 
  6229 * New command 'fixrec' for defining recursive functions with pattern
  6230 matching; defining multiple functions with mutual recursion is also
  6231 supported.  Patterns may include the constants cpair, spair, up, sinl,
  6232 sinr, or any data constructor defined by the domain package. The given
  6233 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  6234 syntax and examples.
  6235 
  6236 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  6237 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  6238 but the proof obligation additionally includes an admissibility
  6239 requirement. The packages generate instances of class cpo or pcpo,
  6240 with continuity and strictness theorems for Rep and Abs.
  6241 
  6242 * HOLCF: Many theorems have been renamed according to a more standard naming
  6243 scheme (INCOMPATIBILITY):
  6244 
  6245   foo_inject:  "foo$x = foo$y ==> x = y"
  6246   foo_eq:      "(foo$x = foo$y) = (x = y)"
  6247   foo_less:    "(foo$x << foo$y) = (x << y)"
  6248   foo_strict:  "foo$UU = UU"
  6249   foo_defined: "... ==> foo$x ~= UU"
  6250   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  6251 
  6252 
  6253 *** ZF ***
  6254 
  6255 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  6256 including the First Isomorphism Theorem (on quotienting by the kernel
  6257 of a homomorphism).
  6258 
  6259 * ZF/Simplifier: install second copy of type solver that actually
  6260 makes use of TC rules declared to Isar proof contexts (or locales);
  6261 the old version is still required for ML proof scripts.
  6262 
  6263 
  6264 *** Cube ***
  6265 
  6266 * Converted to Isar theory format; use locales instead of axiomatic
  6267 theories.
  6268 
  6269 
  6270 *** ML ***
  6271 
  6272 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  6273 for ||>, ||>>, |>>,
  6274 
  6275 * Pure/library.ML no longer defines its own option datatype, but uses
  6276 that of the SML basis, which has constructors NONE and SOME instead of
  6277 None and Some, as well as exception Option.Option instead of OPTION.
  6278 The functions the, if_none, is_some, is_none have been adapted
  6279 accordingly, while Option.map replaces apsome.
  6280 
  6281 * Pure/library.ML: the exception LIST has been given up in favour of
  6282 the standard exceptions Empty and Subscript, as well as
  6283 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6284 superceded by the standard hd and tl functions etc.
  6285 
  6286 A number of basic list functions are no longer exported to the ML
  6287 toplevel, as they are variants of predefined functions.  The following
  6288 suggests how one can translate existing code:
  6289 
  6290     rev_append xs ys = List.revAppend (xs, ys)
  6291     nth_elem (i, xs) = List.nth (xs, i)
  6292     last_elem xs = List.last xs
  6293     flat xss = List.concat xss
  6294     seq fs = List.app fs
  6295     partition P xs = List.partition P xs
  6296     mapfilter f xs = List.mapPartial f xs
  6297 
  6298 * Pure/library.ML: several combinators for linear functional
  6299 transformations, notably reverse application and composition:
  6300 
  6301   x |> f                f #> g
  6302   (x, y) |-> f          f #-> g
  6303 
  6304 * Pure/library.ML: introduced/changed precedence of infix operators:
  6305 
  6306   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6307   infix 2 ?;
  6308   infix 3 o oo ooo oooo;
  6309   infix 4 ~~ upto downto;
  6310 
  6311 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6312 infix operators.
  6313 
  6314 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6315 fold_map support linear functional transformations and nesting.  For
  6316 example:
  6317 
  6318   fold f [x1, ..., xN] y =
  6319     y |> f x1 |> ... |> f xN
  6320 
  6321   (fold o fold) f [xs1, ..., xsN] y =
  6322     y |> fold f xs1 |> ... |> fold f xsN
  6323 
  6324   fold f [x1, ..., xN] =
  6325     f x1 #> ... #> f xN
  6326 
  6327   (fold o fold) f [xs1, ..., xsN] =
  6328     fold f xs1 #> ... #> fold f xsN
  6329 
  6330 * Pure/library.ML: the following selectors on type 'a option are
  6331 available:
  6332 
  6333   the:               'a option -> 'a  (*partial*)
  6334   these:             'a option -> 'a  where 'a = 'b list
  6335   the_default: 'a -> 'a option -> 'a
  6336   the_list:          'a option -> 'a list
  6337 
  6338 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6339 basic operations for association lists, following natural argument
  6340 order; moreover the explicit equality predicate passed here avoids
  6341 potentially expensive polymorphic runtime equality checks.
  6342 The old functions may be expressed as follows:
  6343 
  6344   assoc = uncurry (AList.lookup (op =))
  6345   assocs = these oo AList.lookup (op =)
  6346   overwrite = uncurry (AList.update (op =)) o swap
  6347 
  6348 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6349 
  6350   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6351   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6352 
  6353 replacing make_keylist and keyfilter (occassionally used)
  6354 Naive rewrites:
  6355 
  6356   make_keylist = AList.make
  6357   keyfilter = AList.find (op =)
  6358 
  6359 * eq_fst and eq_snd now take explicit equality parameter, thus
  6360   avoiding eqtypes. Naive rewrites:
  6361 
  6362     eq_fst = eq_fst (op =)
  6363     eq_snd = eq_snd (op =)
  6364 
  6365 * Removed deprecated apl and apr (rarely used).
  6366   Naive rewrites:
  6367 
  6368     apl (n, op) =>>= curry op n
  6369     apr (op, m) =>>= fn n => op (n, m)
  6370 
  6371 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6372 provides a reasonably efficient light-weight implementation of sets as
  6373 lists.
  6374 
  6375 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6376 few new operations; existing lookup and update are now curried to
  6377 follow natural argument order (for use with fold etc.);
  6378 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6379 
  6380 * Pure/General: output via the Isabelle channels of
  6381 writeln/warning/error etc. is now passed through Output.output, with a
  6382 hook for arbitrary transformations depending on the print_mode
  6383 (cf. Output.add_mode -- the first active mode that provides a output
  6384 function wins).  Already formatted output may be embedded into further
  6385 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6386 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6387 accommodate easy composition of diagnostic messages etc.  Programmers
  6388 rarely need to care about Output.output or Output.raw at all, with
  6389 some notable exceptions: Output.output is required when bypassing the
  6390 standard channels (writeln etc.), or in token translations to produce
  6391 properly formatted results; Output.raw is required when capturing
  6392 already output material that will eventually be presented to the user
  6393 a second time.  For the default print mode, both Output.output and
  6394 Output.raw have no effect.
  6395 
  6396 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6397 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6398 cumulative results are displayed at the end of a batch session.
  6399 
  6400 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6401 replaced by File.platform_path and File.shell_path (with appropriate
  6402 hooks).  This provides a clean interface for unusual systems where the
  6403 internal and external process view of file names are different.
  6404 
  6405 * Pure: more efficient orders for basic syntactic entities: added
  6406 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6407 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6408 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6409 orders now -- potential INCOMPATIBILITY for code that depends on a
  6410 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6411 Library.sort_strings on result).
  6412 
  6413 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6414 fold_types traverse types/terms from left to right, observing natural
  6415 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6416 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6417 
  6418 * Pure: name spaces have been refined, with significant changes of the
  6419 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6420 to extern(_table).  The plain name entry path is superceded by a
  6421 general 'naming' context, which also includes the 'policy' to produce
  6422 a fully qualified name and external accesses of a fully qualified
  6423 name; NameSpace.extend is superceded by context dependent
  6424 Sign.declare_name.  Several theory and proof context operations modify
  6425 the naming context.  Especially note Theory.restore_naming and
  6426 ProofContext.restore_naming to get back to a sane state; note that
  6427 Theory.add_path is no longer sufficient to recover from
  6428 Theory.absolute_path in particular.
  6429 
  6430 * Pure: new flags short_names (default false) and unique_names
  6431 (default true) for controlling output of qualified names.  If
  6432 short_names is set, names are printed unqualified.  If unique_names is
  6433 reset, the name prefix is reduced to the minimum required to achieve
  6434 the original result when interning again, even if there is an overlap
  6435 with earlier declarations.
  6436 
  6437 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  6438 now 'extend', and 'merge' gets an additional Pretty.pp argument
  6439 (useful for printing error messages).  INCOMPATIBILITY.
  6440 
  6441 * Pure: major reorganization of the theory context.  Type Sign.sg and
  6442 Theory.theory are now identified, referring to the universal
  6443 Context.theory (see Pure/context.ML).  Actual signature and theory
  6444 content is managed as theory data.  The old code and interfaces were
  6445 spread over many files and structures; the new arrangement introduces
  6446 considerable INCOMPATIBILITY to gain more clarity:
  6447 
  6448   Context -- theory management operations (name, identity, inclusion,
  6449     parents, ancestors, merge, etc.), plus generic theory data;
  6450 
  6451   Sign -- logical signature and syntax operations (declaring consts,
  6452     types, etc.), plus certify/read for common entities;
  6453 
  6454   Theory -- logical theory operations (stating axioms, definitions,
  6455     oracles), plus a copy of logical signature operations (consts,
  6456     types, etc.); also a few basic management operations (Theory.copy,
  6457     Theory.merge, etc.)
  6458 
  6459 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  6460 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  6461 for convenience -- they merely return the theory.
  6462 
  6463 * Pure: type Type.tsig is superceded by theory in most interfaces.
  6464 
  6465 * Pure: the Isar proof context type is already defined early in Pure
  6466 as Context.proof (note that ProofContext.context and Proof.context are
  6467 aliases, where the latter is the preferred name).  This enables other
  6468 Isabelle components to refer to that type even before Isar is present.
  6469 
  6470 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  6471 typeK, constK, axiomK, oracleK), but provide explicit operations for
  6472 any of these kinds.  For example, Sign.intern typeK is now
  6473 Sign.intern_type, Theory.hide_space Sign.typeK is now
  6474 Theory.hide_types.  Also note that former
  6475 Theory.hide_classes/types/consts are now
  6476 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  6477 internalize their arguments!  INCOMPATIBILITY.
  6478 
  6479 * Pure: get_thm interface (of PureThy and ProofContext) expects
  6480 datatype thmref (with constructors Name and NameSelection) instead of
  6481 plain string -- INCOMPATIBILITY;
  6482 
  6483 * Pure: cases produced by proof methods specify options, where NONE
  6484 means to remove case bindings -- INCOMPATIBILITY in
  6485 (RAW_)METHOD_CASES.
  6486 
  6487 * Pure: the following operations retrieve axioms or theorems from a
  6488 theory node or theory hierarchy, respectively:
  6489 
  6490   Theory.axioms_of: theory -> (string * term) list
  6491   Theory.all_axioms_of: theory -> (string * term) list
  6492   PureThy.thms_of: theory -> (string * thm) list
  6493   PureThy.all_thms_of: theory -> (string * thm) list
  6494 
  6495 * Pure: print_tac now outputs the goal through the trace channel.
  6496 
  6497 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  6498 Reference Toplevel.debug (default false) controls detailed printing
  6499 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  6500 controls execution profiling -- set to 1 for time and 2 for space
  6501 (both increase the runtime).
  6502 
  6503 * Isar session: The initial use of ROOT.ML is now always timed,
  6504 i.e. the log will show the actual process times, in contrast to the
  6505 elapsed wall-clock time that the outer shell wrapper produces.
  6506 
  6507 * Simplifier: improved handling of bound variables (nameless
  6508 representation, avoid allocating new strings).  Simprocs that invoke
  6509 the Simplifier recursively should use Simplifier.inherit_bounds to
  6510 avoid local name clashes.  Failure to do so produces warnings
  6511 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  6512 for further details.
  6513 
  6514 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  6515 bindings for all theorems stored within a given theory; this may help
  6516 in porting non-Isar theories to Isar ones, while keeping ML proof
  6517 scripts for the time being.
  6518 
  6519 * ML operator HTML.with_charset specifies the charset begin used for
  6520 generated HTML files.  For example:
  6521 
  6522   HTML.with_charset "utf-8" use_thy "Hebrew";
  6523   HTML.with_charset "utf-8" use_thy "Chinese";
  6524 
  6525 
  6526 *** System ***
  6527 
  6528 * Allow symlinks to all proper Isabelle executables (Isabelle,
  6529 isabelle, isatool etc.).
  6530 
  6531 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  6532 isatool doc, isatool mkdir, display_drafts etc.).
  6533 
  6534 * isatool usedir: option -f allows specification of the ML file to be
  6535 used by Isabelle; default is ROOT.ML.
  6536 
  6537 * New isatool version outputs the version identifier of the Isabelle
  6538 distribution being used.
  6539 
  6540 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  6541 (containing Boolean satisfiability problems) into Isabelle/HOL
  6542 theories.
  6543 
  6544 
  6545 
  6546 New in Isabelle2004 (April 2004)
  6547 --------------------------------
  6548 
  6549 *** General ***
  6550 
  6551 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  6552   Replaces linorder.ML.
  6553 
  6554 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  6555   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  6556   (\<a>...\<z>), are now considered normal letters, and can therefore
  6557   be used anywhere where an ASCII letter (a...zA...Z) has until
  6558   now. COMPATIBILITY: This obviously changes the parsing of some
  6559   terms, especially where a symbol has been used as a binder, say
  6560   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  6561   as an identifier.  Fix it by inserting a space around former
  6562   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  6563   existing theory and ML files.
  6564 
  6565 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  6566 
  6567 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  6568   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  6569   a normal (but invisible) letter. For multiple letter subscripts repeat
  6570   \<^isub> like this: x\<^isub>1\<^isub>2.
  6571 
  6572 * Pure: There are now sub-/superscripts that can span more than one
  6573   character. Text between \<^bsub> and \<^esub> is set in subscript in
  6574   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  6575   superscript. The new control characters are not identifier parts.
  6576 
  6577 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  6578   content of "..." to the latex file instead of \isacntrl... . The "..."
  6579   may consist of any printable characters excluding the end bracket >.
  6580 
  6581 * Pure: Using new Isar command "finalconsts" (or the ML functions
  6582   Theory.add_finals or Theory.add_finals_i) it is now possible to
  6583   declare constants "final", which prevents their being given a definition
  6584   later.  It is useful for constants whose behaviour is fixed axiomatically
  6585   rather than definitionally, such as the meta-logic connectives.
  6586 
  6587 * Pure: 'instance' now handles general arities with general sorts
  6588   (i.e. intersections of classes),
  6589 
  6590 * Presentation: generated HTML now uses a CSS style sheet to make layout
  6591   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  6592   It can be changed to alter the colors/layout of generated pages.
  6593 
  6594 
  6595 *** Isar ***
  6596 
  6597 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  6598   cut_tac, subgoal_tac and thin_tac:
  6599   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  6600     locales are no longer forced to write Isar proof scripts.
  6601     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  6602     emulations.
  6603   - INCOMPATIBILITY: names of variables to be instantiated may no
  6604     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  6605     This is consistent with the instantiation attribute "where".
  6606 
  6607 * Attributes "where" and "of":
  6608   - Now take type variables of instantiated theorem into account when reading
  6609     the instantiation string.  This fixes a bug that caused instantiated
  6610     theorems to have too special types in some circumstances.
  6611   - "where" permits explicit instantiations of type variables.
  6612 
  6613 * Calculation commands "moreover" and "also" no longer interfere with
  6614   current facts ("this"), admitting arbitrary combinations with "then"
  6615   and derived forms.
  6616 
  6617 * Locales:
  6618   - Goal statements involving the context element "includes" no longer
  6619     generate theorems with internal delta predicates (those ending on
  6620     "_axioms") in the premise.
  6621     Resolve particular premise with <locale>.intro to obtain old form.
  6622   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  6623     specification and "includes" elements in goal statement.
  6624   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  6625     [intro?] and [elim?] (respectively) by default.
  6626   - Experimental command for instantiation of locales in proof contexts:
  6627         instantiate <label>[<attrs>]: <loc>
  6628     Instantiates locale <loc> and adds all its theorems to the current context
  6629     taking into account their attributes.  Label and attrs are optional
  6630     modifiers, like in theorem declarations.  If present, names of
  6631     instantiated theorems are qualified with <label>, and the attributes
  6632     <attrs> are applied after any attributes these theorems might have already.
  6633       If the locale has assumptions, a chained fact of the form
  6634     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  6635     are derived.  The command does not support old-style locales declared
  6636     with "locale (open)".
  6637       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  6638 
  6639 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  6640   (Isar) contexts.
  6641 
  6642 
  6643 *** HOL ***
  6644 
  6645 * Proof import: new image HOL4 contains the imported library from
  6646   the HOL4 system with about 2500 theorems. It is imported by
  6647   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  6648   can be used like any other Isabelle image.  See
  6649   HOL/Import/HOL/README for more information.
  6650 
  6651 * Simplifier:
  6652   - Much improved handling of linear and partial orders.
  6653     Reasoners for linear and partial orders are set up for type classes
  6654     "linorder" and "order" respectively, and are added to the default simpset
  6655     as solvers.  This means that the simplifier can build transitivity chains
  6656     to solve goals from the assumptions.
  6657   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  6658     of blast or auto after simplification become unnecessary because the goal
  6659     is solved by simplification already.
  6660 
  6661 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  6662     all proved in axiomatic type classes for semirings, rings and fields.
  6663 
  6664 * Numerics:
  6665   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  6666     now formalized using the Ring_and_Field theory mentioned above.
  6667   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  6668     than before, because now they are set up once in a generic manner.
  6669   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  6670     Look for the general versions in Ring_and_Field (and Power if they concern
  6671     exponentiation).
  6672 
  6673 * Type "rat" of the rational numbers is now available in HOL-Complex.
  6674 
  6675 * Records:
  6676   - Record types are now by default printed with their type abbreviation
  6677     instead of the list of all field types. This can be configured via
  6678     the reference "print_record_type_abbr".
  6679   - Simproc "record_upd_simproc" for simplification of multiple updates added
  6680     (not enabled by default).
  6681   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  6682     EX x. x = sel r to True (not enabled by default).
  6683   - Tactic "record_split_simp_tac" to split and simplify records added.
  6684 
  6685 * 'specification' command added, allowing for definition by
  6686   specification.  There is also an 'ax_specification' command that
  6687   introduces the new constants axiomatically.
  6688 
  6689 * arith(_tac) is now able to generate counterexamples for reals as well.
  6690 
  6691 * HOL-Algebra: new locale "ring" for non-commutative rings.
  6692 
  6693 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  6694   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  6695 
  6696 * HOL-Matrix: a first theory for matrices in HOL with an application of
  6697   matrix theory to linear programming.
  6698 
  6699 * Unions and Intersections:
  6700   The latex output syntax of UN and INT has been changed
  6701   from "\Union x \in A. B" to "\Union_{x \in A} B"
  6702   i.e. the index formulae has become a subscript.
  6703   Similarly for "\Union x. B", and for \Inter instead of \Union.
  6704 
  6705 * Unions and Intersections over Intervals:
  6706   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  6707   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  6708   like in normal math, and corresponding versions for < and for intersection.
  6709 
  6710 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  6711   lexicographic dictonary ordering has been added as "lexord".
  6712 
  6713 * ML: the legacy theory structures Int and List have been removed. They had
  6714   conflicted with ML Basis Library structures having the same names.
  6715 
  6716 * 'refute' command added to search for (finite) countermodels.  Only works
  6717   for a fragment of HOL.  The installation of an external SAT solver is
  6718   highly recommended.  See "HOL/Refute.thy" for details.
  6719 
  6720 * 'quickcheck' command: Allows to find counterexamples by evaluating
  6721   formulae under an assignment of free variables to random values.
  6722   In contrast to 'refute', it can deal with inductive datatypes,
  6723   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  6724   for examples.
  6725 
  6726 
  6727 *** HOLCF ***
  6728 
  6729 * Streams now come with concatenation and are part of the HOLCF image
  6730 
  6731 
  6732 
  6733 New in Isabelle2003 (May 2003)
  6734 ------------------------------
  6735 
  6736 *** General ***
  6737 
  6738 * Provers/simplifier:
  6739 
  6740   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  6741     Assumptions are now subject to complete mutual simplification,
  6742     not just from left to right. The simplifier now preserves
  6743     the order of assumptions.
  6744 
  6745     Potential INCOMPATIBILITY:
  6746 
  6747     -- simp sometimes diverges where the old version did
  6748        not, e.g. invoking simp on the goal
  6749 
  6750         [| P (f x); y = x; f x = f y |] ==> Q
  6751 
  6752        now gives rise to the infinite reduction sequence
  6753 
  6754         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  6755 
  6756        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  6757        kind of problem.
  6758 
  6759     -- Tactics combining classical reasoner and simplification (such as auto)
  6760        are also affected by this change, because many of them rely on
  6761        simp. They may sometimes diverge as well or yield a different numbers
  6762        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  6763        in case of problems. Sometimes subsequent calls to the classical
  6764        reasoner will fail because a preceeding call to the simplifier too
  6765        eagerly simplified the goal, e.g. deleted redundant premises.
  6766 
  6767   - The simplifier trace now shows the names of the applied rewrite rules
  6768 
  6769   - You can limit the number of recursive invocations of the simplifier
  6770     during conditional rewriting (where the simplifie tries to solve the
  6771     conditions before applying the rewrite rule):
  6772     ML "simp_depth_limit := n"
  6773     where n is an integer. Thus you can force termination where previously
  6774     the simplifier would diverge.
  6775 
  6776   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  6777 
  6778   - No longer aborts on failed congruence proof.  Instead, the
  6779     congruence is ignored.
  6780 
  6781 * Pure: New generic framework for extracting programs from constructive
  6782   proofs. See HOL/Extraction.thy for an example instantiation, as well
  6783   as HOL/Extraction for some case studies.
  6784 
  6785 * Pure: The main goal of the proof state is no longer shown by default, only
  6786 the subgoals. This behaviour is controlled by a new flag.
  6787    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  6788 (ML: Proof.show_main_goal).
  6789 
  6790 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  6791 rules whose conclusion matches subgoal 1:
  6792       PG menu: Isabelle/Isar -> Show me -> matching rules
  6793 The rules are ordered by how closely they match the subgoal.
  6794 In particular, rules that solve a subgoal outright are displayed first
  6795 (or rather last, the way they are printed).
  6796 (ML: ProofGeneral.print_intros())
  6797 
  6798 * Pure: New flag trace_unify_fail causes unification to print
  6799 diagnostic information (PG: in trace buffer) when it fails. This is
  6800 useful for figuring out why single step proofs like rule, erule or
  6801 assumption failed.
  6802 
  6803 * Pure: Locale specifications now produce predicate definitions
  6804 according to the body of text (covering assumptions modulo local
  6805 definitions); predicate "loc_axioms" covers newly introduced text,
  6806 while "loc" is cumulative wrt. all included locale expressions; the
  6807 latter view is presented only on export into the global theory
  6808 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  6809 on the old view without predicates;
  6810 
  6811 * Pure: predefined locales "var" and "struct" are useful for sharing
  6812 parameters (as in CASL, for example); just specify something like
  6813 ``var x + var y + struct M'' as import;
  6814 
  6815 * Pure: improved thms_containing: proper indexing of facts instead of
  6816 raw theorems; check validity of results wrt. current name space;
  6817 include local facts of proof configuration (also covers active
  6818 locales), cover fixed variables in index; may use "_" in term
  6819 specification; an optional limit for the number of printed facts may
  6820 be given (the default is 40);
  6821 
  6822 * Pure: disallow duplicate fact bindings within new-style theory files
  6823 (batch-mode only);
  6824 
  6825 * Provers: improved induct method: assumptions introduced by case
  6826 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6827 the goal statement); "foo" still refers to all facts collectively;
  6828 
  6829 * Provers: the function blast.overloaded has been removed: all constants
  6830 are regarded as potentially overloaded, which improves robustness in exchange
  6831 for slight decrease in efficiency;
  6832 
  6833 * Provers/linorder: New generic prover for transitivity reasoning over
  6834 linear orders.  Note: this prover is not efficient!
  6835 
  6836 * Isar: preview of problems to finish 'show' now produce an error
  6837 rather than just a warning (in interactive mode);
  6838 
  6839 
  6840 *** HOL ***
  6841 
  6842 * arith(_tac)
  6843 
  6844  - Produces a counter example if it cannot prove a goal.
  6845    Note that the counter example may be spurious if the goal is not a formula
  6846    of quantifier-free linear arithmetic.
  6847    In ProofGeneral the counter example appears in the trace buffer.
  6848 
  6849  - Knows about div k and mod k where k is a numeral of type nat or int.
  6850 
  6851  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6852    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6853    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6854 
  6855 * simp's arithmetic capabilities have been enhanced a bit: it now
  6856 takes ~= in premises into account (by performing a case split);
  6857 
  6858 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6859 are distributed over a sum of terms;
  6860 
  6861 * New tactic "trans_tac" and method "trans" instantiate
  6862 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6863 "<=", "<" and "=").
  6864 
  6865 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6866 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6867 
  6868 * 'typedef' command has new option "open" to suppress the set
  6869 definition;
  6870 
  6871 * functions Min and Max on finite sets have been introduced (theory
  6872 Finite_Set);
  6873 
  6874 * attribute [symmetric] now works for relations as well; it turns
  6875 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6876 
  6877 * induct over a !!-quantified statement (say !!x1..xn):
  6878   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6879 
  6880 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6881 %x. None. Warning: empty_def now refers to the previously hidden definition
  6882 of the empty set.
  6883 
  6884 * Algebra: formalization of classical algebra.  Intended as base for
  6885 any algebraic development in Isabelle.  Currently covers group theory
  6886 (up to Sylow's theorem) and ring theory (Universal Property of
  6887 Univariate Polynomials).  Contributions welcome;
  6888 
  6889 * GroupTheory: deleted, since its material has been moved to Algebra;
  6890 
  6891 * Complex: new directory of the complex numbers with numeric constants,
  6892 nonstandard complex numbers, and some complex analysis, standard and
  6893 nonstandard (Jacques Fleuriot);
  6894 
  6895 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6896 
  6897 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6898 Fleuriot);
  6899 
  6900 * Real/HahnBanach: updated and adapted to locales;
  6901 
  6902 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6903 Gray and Kramer);
  6904 
  6905 * UNITY: added the Meier-Sanders theory of progress sets;
  6906 
  6907 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6908 as abstract algorithms, instantiated to the JVM;
  6909 
  6910 * Bali: Java source language formalization. Type system, operational
  6911 semantics, axiomatic semantics. Supported language features:
  6912 classes, interfaces, objects,virtual methods, static methods,
  6913 static/instance fields, arrays, access modifiers, definite
  6914 assignment, exceptions.
  6915 
  6916 
  6917 *** ZF ***
  6918 
  6919 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6920 universe, etc.);
  6921 
  6922 * Main ZF: virtually all theories converted to new-style format;
  6923 
  6924 
  6925 *** ML ***
  6926 
  6927 * Pure: Tactic.prove provides sane interface for internal proofs;
  6928 omits the infamous "standard" operation, so this is more appropriate
  6929 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6930 
  6931 * Pure: improved error reporting of simprocs;
  6932 
  6933 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6934 up simprocs;
  6935 
  6936 
  6937 *** Document preparation ***
  6938 
  6939 * uses \par instead of \\ for line breaks in theory text. This may
  6940 shift some page breaks in large documents. To get the old behaviour
  6941 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6942 
  6943 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6944 other packages
  6945 
  6946 * \<euro> now needs package babel/greek instead of marvosym (which
  6947 broke \Rightarrow)
  6948 
  6949 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6950 textcomp package)
  6951 
  6952 
  6953 
  6954 New in Isabelle2002 (March 2002)
  6955 --------------------------------
  6956 
  6957 *** Document preparation ***
  6958 
  6959 * greatly simplified document preparation setup, including more
  6960 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6961 instructive isatool mkdir; users should basically be able to get
  6962 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6963 users may run a separate document processing stage manually like this:
  6964 "isatool usedir -D output HOL Test && isatool document Test/output";
  6965 
  6966 * theory dependency graph may now be incorporated into documents;
  6967 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6968 with \includegraphics of LaTeX;
  6969 
  6970 * proper spacing of consecutive markup elements, especially text
  6971 blocks after section headings;
  6972 
  6973 * support bold style (for single symbols only), input syntax is like
  6974 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6975 
  6976 * \<bullet> is now output as bold \cdot by default, which looks much
  6977 better in printed text;
  6978 
  6979 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6980 note that these symbols are currently unavailable in Proof General /
  6981 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6982 
  6983 * isatool latex no longer depends on changed TEXINPUTS, instead
  6984 isatool document copies the Isabelle style files to the target
  6985 location;
  6986 
  6987 
  6988 *** Isar ***
  6989 
  6990 * Pure/Provers: improved proof by cases and induction;
  6991   - 'case' command admits impromptu naming of parameters (such as
  6992     "case (Suc n)");
  6993   - 'induct' method divinates rule instantiation from the inductive
  6994     claim; no longer requires excessive ?P bindings for proper
  6995     instantiation of cases;
  6996   - 'induct' method properly enumerates all possibilities of set/type
  6997     rules; as a consequence facts may be also passed through *type*
  6998     rules without further ado;
  6999   - 'induct' method now derives symbolic cases from the *rulified*
  7000     rule (before it used to rulify cases stemming from the internal
  7001     atomized version); this means that the context of a non-atomic
  7002     statement becomes is included in the hypothesis, avoiding the
  7003     slightly cumbersome show "PROP ?case" form;
  7004   - 'induct' may now use elim-style induction rules without chaining
  7005     facts, using ``missing'' premises from the goal state; this allows
  7006     rules stemming from inductive sets to be applied in unstructured
  7007     scripts, while still benefitting from proper handling of non-atomic
  7008     statements; NB: major inductive premises need to be put first, all
  7009     the rest of the goal is passed through the induction;
  7010   - 'induct' proper support for mutual induction involving non-atomic
  7011     rule statements (uses the new concept of simultaneous goals, see
  7012     below);
  7013   - append all possible rule selections, but only use the first
  7014     success (no backtracking);
  7015   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  7016   - undeclared rule case names default to numbers 1, 2, 3, ...;
  7017   - added 'print_induct_rules' (covered by help item in recent Proof
  7018     General versions);
  7019   - moved induct/cases attributes to Pure, methods to Provers;
  7020   - generic method setup instantiated for FOL and HOL;
  7021 
  7022 * Pure: support multiple simultaneous goal statements, for example
  7023 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  7024 meta-level mechanism, this acts as if several individual goals had
  7025 been stated separately; in particular common proof methods need to be
  7026 repeated in order to cover all claims; note that a single elimination
  7027 step is *not* sufficient to establish the two conjunctions, so this
  7028 fails:
  7029 
  7030   assume "A & B" then have A and B ..   (*".." fails*)
  7031 
  7032 better use "obtain" in situations as above; alternative refer to
  7033 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  7034 
  7035 * Pure: proper integration with ``locales''; unlike the original
  7036 version by Florian Kammller, Isar locales package high-level proof
  7037 contexts rather than raw logical ones (e.g. we admit to include
  7038 attributes everywhere); operations on locales include merge and
  7039 rename; support for implicit arguments (``structures''); simultaneous
  7040 type-inference over imports and text; see also HOL/ex/Locales.thy for
  7041 some examples;
  7042 
  7043 * Pure: the following commands have been ``localized'', supporting a
  7044 target locale specification "(in name)": 'lemma', 'theorem',
  7045 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  7046 stored both within the locale and at the theory level (exported and
  7047 qualified by the locale name);
  7048 
  7049 * Pure: theory goals may now be specified in ``long'' form, with
  7050 ad-hoc contexts consisting of arbitrary locale elements. for example
  7051 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  7052 definitions may be given, too); the result is a meta-level rule with
  7053 the context elements being discharged in the obvious way;
  7054 
  7055 * Pure: new proof command 'using' allows to augment currently used
  7056 facts after a goal statement ('using' is syntactically analogous to
  7057 'apply', but acts on the goal's facts only); this allows chained facts
  7058 to be separated into parts given before and after a claim, as in
  7059 ``from a and b have C using d and e <proof>'';
  7060 
  7061 * Pure: renamed "antecedent" case to "rule_context";
  7062 
  7063 * Pure: new 'judgment' command records explicit information about the
  7064 object-logic embedding (used by several tools internally); no longer
  7065 use hard-wired "Trueprop";
  7066 
  7067 * Pure: added 'corollary' command;
  7068 
  7069 * Pure: fixed 'token_translation' command;
  7070 
  7071 * Pure: removed obsolete 'exported' attribute;
  7072 
  7073 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  7074 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  7075 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  7076 
  7077 * Pure: method 'atomize' presents local goal premises as object-level
  7078 statements (atomic meta-level propositions); setup controlled via
  7079 rewrite rules declarations of 'atomize' attribute; example
  7080 application: 'induct' method with proper rule statements in improper
  7081 proof *scripts*;
  7082 
  7083 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  7084 now consider the syntactic context of assumptions, giving a better
  7085 chance to get type-inference of the arguments right (this is
  7086 especially important for locales);
  7087 
  7088 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  7089 mode;
  7090 
  7091 * Pure/obtain: the formal conclusion "thesis", being marked as
  7092 ``internal'', may no longer be reference directly in the text;
  7093 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  7094 situations;
  7095 
  7096 * Pure: generic 'sym' attribute which declares a rule both as pure
  7097 'elim?' and for the 'symmetric' operation;
  7098 
  7099 * Pure: marginal comments ``--'' may now occur just anywhere in the
  7100 text; the fixed correlation with particular command syntax has been
  7101 discontinued;
  7102 
  7103 * Pure: new method 'rules' is particularly well-suited for proof
  7104 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  7105 but often produces more compact proof terms with less detours;
  7106 
  7107 * Pure/Provers/classical: simplified integration with pure rule
  7108 attributes and methods; the classical "intro?/elim?/dest?"
  7109 declarations coincide with the pure ones; the "rule" method no longer
  7110 includes classically swapped intros; "intro" and "elim" methods no
  7111 longer pick rules from the context; also got rid of ML declarations
  7112 AddXIs/AddXEs/AddXDs; all of this has some potential for
  7113 INCOMPATIBILITY;
  7114 
  7115 * Provers/classical: attribute 'swapped' produces classical inversions
  7116 of introduction rules;
  7117 
  7118 * Provers/simplifier: 'simplified' attribute may refer to explicit
  7119 rules instead of full simplifier context; 'iff' attribute handles
  7120 conditional rules;
  7121 
  7122 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  7123 
  7124 * HOL: 'recdef' now fails on unfinished automated proofs, use
  7125 "(permissive)" option to recover old behavior;
  7126 
  7127 * HOL: 'inductive' no longer features separate (collective) attributes
  7128 for 'intros' (was found too confusing);
  7129 
  7130 * HOL: properly declared induction rules less_induct and
  7131 wf_induct_rule;
  7132 
  7133 
  7134 *** HOL ***
  7135 
  7136 * HOL: moved over to sane numeral syntax; the new policy is as
  7137 follows:
  7138 
  7139   - 0 and 1 are polymorphic constants, which are defined on any
  7140   numeric type (nat, int, real etc.);
  7141 
  7142   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  7143   binary representation internally;
  7144 
  7145   - type nat has special constructor Suc, and generally prefers Suc 0
  7146   over 1::nat and Suc (Suc 0) over 2::nat;
  7147 
  7148 This change may cause significant problems of INCOMPATIBILITY; here
  7149 are some hints on converting existing sources:
  7150 
  7151   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  7152   entities, so expressions involving "-" (unary or binary minus) need
  7153   to be spaced properly;
  7154 
  7155   - existing occurrences of "1" may need to be constraint "1::nat" or
  7156   even replaced by Suc 0; similar for old "2";
  7157 
  7158   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  7159 
  7160   - remove all special provisions on numerals in proofs;
  7161 
  7162 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  7163 representation (depends on bin_arith_simps in the default context);
  7164 
  7165 * HOL: symbolic syntax for x^2 (numeral 2);
  7166 
  7167 * HOL: the class of all HOL types is now called "type" rather than
  7168 "term"; INCOMPATIBILITY, need to adapt references to this type class
  7169 in axclass/classes, instance/arities, and (usually rare) occurrences
  7170 in typings (of consts etc.); internally the class is called
  7171 "HOL.type", ML programs should refer to HOLogic.typeS;
  7172 
  7173 * HOL/record package improvements:
  7174   - new derived operations "fields" to build a partial record section,
  7175     "extend" to promote a fixed record to a record scheme, and
  7176     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  7177     declared as simp by default;
  7178   - shared operations ("more", "fields", etc.) now need to be always
  7179     qualified) --- potential INCOMPATIBILITY;
  7180   - removed "make_scheme" operations (use "make" with "extend") --
  7181     INCOMPATIBILITY;
  7182   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  7183   - provides cases/induct rules for use with corresponding Isar
  7184     methods (for concrete records, record schemes, concrete more
  7185     parts, and schematic more parts -- in that order);
  7186   - internal definitions directly based on a light-weight abstract
  7187     theory of product types over typedef rather than datatype;
  7188 
  7189 * HOL: generic code generator for generating executable ML code from
  7190 specifications; specific support for HOL constructs such as inductive
  7191 datatypes and sets, as well as recursive functions; can be invoked
  7192 via 'generate_code' theory section;
  7193 
  7194 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  7195 
  7196 * HOL: consolidated and renamed several theories.  In particular:
  7197         Ord.thy has been absorbed into HOL.thy
  7198         String.thy has been absorbed into List.thy
  7199 
  7200 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  7201 (beware of argument permutation!);
  7202 
  7203 * HOL: linorder_less_split superseded by linorder_cases;
  7204 
  7205 * HOL/List: "nodups" renamed to "distinct";
  7206 
  7207 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  7208 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  7209   - Ex_def has changed, now need to use some_eq_ex
  7210 
  7211 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  7212 in this (rare) case use:
  7213 
  7214   delSWrapper "split_all_tac"
  7215   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  7216 
  7217 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  7218 MAY FAIL;
  7219 
  7220 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  7221 Isabelle's type classes, ^ on functions and relations has too general
  7222 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  7223 necessary to attach explicit type constraints;
  7224 
  7225 * HOL/Relation: the prefix name of the infix "O" has been changed from
  7226 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  7227 renamed accordingly (eg "compI" -> "rel_compI").
  7228 
  7229 * HOL: syntax translations now work properly with numerals and records
  7230 expressions;
  7231 
  7232 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  7233 of "lam" -- INCOMPATIBILITY;
  7234 
  7235 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  7236 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  7237 renamed "Product_Type.unit";
  7238 
  7239 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  7240 
  7241 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  7242 the "cases" method);
  7243 
  7244 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  7245 Florian Kammller);
  7246 
  7247 * HOL/IMP: updated and converted to new-style theory format; several
  7248 parts turned into readable document, with proper Isar proof texts and
  7249 some explanations (by Gerwin Klein);
  7250 
  7251 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  7252 
  7253 * HOL-Hyperreal is now a logic image;
  7254 
  7255 
  7256 *** HOLCF ***
  7257 
  7258 * Isar: consts/constdefs supports mixfix syntax for continuous
  7259 operations;
  7260 
  7261 * Isar: domain package adapted to new-style theory format, e.g. see
  7262 HOLCF/ex/Dnat.thy;
  7263 
  7264 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  7265 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  7266 lift.induct_tac, always use UU instead of Undef;
  7267 
  7268 * HOLCF/IMP: updated and converted to new-style theory;
  7269 
  7270 
  7271 *** ZF ***
  7272 
  7273 * Isar: proper integration of logic-specific tools and packages,
  7274 including theory commands '(co)inductive', '(co)datatype',
  7275 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  7276 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7277 
  7278 * theory Main no longer includes AC; for the Axiom of Choice, base
  7279 your theory on Main_ZFC;
  7280 
  7281 * the integer library now covers quotients and remainders, with many
  7282 laws relating division to addition, multiplication, etc.;
  7283 
  7284 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7285 typeless version of the formalism;
  7286 
  7287 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7288 format;
  7289 
  7290 * ZF/Induct: new directory for examples of inductive definitions,
  7291 including theory Multiset for multiset orderings; converted to
  7292 new-style theory format;
  7293 
  7294 * ZF: many new theorems about lists, ordinals, etc.;
  7295 
  7296 
  7297 *** General ***
  7298 
  7299 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7300 variable proof controls level of detail: 0 = no proofs (only oracle
  7301 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7302 also ref manual for further ML interfaces;
  7303 
  7304 * Pure/axclass: removed obsolete ML interface
  7305 goal_subclass/goal_arity;
  7306 
  7307 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7308 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7309 separate tokens, so expressions involving minus need to be spaced
  7310 properly;
  7311 
  7312 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7313 rather than "infixl" or "infixr";
  7314 
  7315 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7316 sort constraint specifications in type inference; e.g. "x::_::foo"
  7317 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7318 type variable);
  7319 
  7320 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7321 control output of nested => (types); the default behavior is
  7322 "type_brackets";
  7323 
  7324 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7325 tokens into AST constants;
  7326 
  7327 * Pure/syntax: prefer later declarations of translations and print
  7328 translation functions; potential INCOMPATIBILITY: need to reverse
  7329 multiple declarations for same syntax element constant;
  7330 
  7331 * Pure/show_hyps reset by default (in accordance to existing Isar
  7332 practice);
  7333 
  7334 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7335 addSafter;
  7336 
  7337 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7338 as well;
  7339 
  7340 * system: tested support for MacOS X; should be able to get Isabelle +
  7341 Proof General to work in a plain Terminal after installing Poly/ML
  7342 (e.g. from the Isabelle distribution area) and GNU bash alone
  7343 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7344 support requires further installations, e.g. from
  7345 http://fink.sourceforge.net/);
  7346 
  7347 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7348 
  7349 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7350 of 40 MB), cf. ML_OPTIONS;
  7351 
  7352 * system: Proof General keywords specification is now part of the
  7353 Isabelle distribution (see etc/isar-keywords.el);
  7354 
  7355 * system: support for persistent Proof General sessions (refrain from
  7356 outdating all loaded theories on startup); user may create writable
  7357 logic images like this: ``isabelle -q HOL Test'';
  7358 
  7359 * system: smart selection of Isabelle process versus Isabelle
  7360 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7361 run both "isabelle" and "Isabelle" even if file names are badly
  7362 damaged (executable inspects the case of the first letter of its own
  7363 name); added separate "isabelle-process" and "isabelle-interface";
  7364 
  7365 * system: refrain from any attempt at filtering input streams; no
  7366 longer support ``8bit'' encoding of old isabelle font, instead proper
  7367 iso-latin characters may now be used; the related isatools
  7368 "symbolinput" and "nonascii" have disappeared as well;
  7369 
  7370 * system: removed old "xterm" interface (the print modes "xterm" and
  7371 "xterm_color" are still available for direct use in a suitable
  7372 terminal);
  7373 
  7374 
  7375 
  7376 New in Isabelle99-2 (February 2001)
  7377 -----------------------------------
  7378 
  7379 *** Overview of INCOMPATIBILITIES ***
  7380 
  7381 * HOL: please note that theories in the Library and elsewhere often use the
  7382 new-style (Isar) format; to refer to their theorems in an ML script you must
  7383 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7384 
  7385 * HOL: inductive package no longer splits induction rule aggressively,
  7386 but only as far as specified by the introductions given; the old
  7387 format may be recovered via ML function complete_split_rule or attribute
  7388 'split_rule (complete)';
  7389 
  7390 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7391 gfp_Tarski to gfp_unfold;
  7392 
  7393 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7394 
  7395 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7396 relation); infix "^^" has been renamed "``"; infix "``" has been
  7397 renamed "`"; "univalent" has been renamed "single_valued";
  7398 
  7399 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7400 operation;
  7401 
  7402 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7403 
  7404 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7405 
  7406 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7407 consequence, it is no longer monotonic wrt. the local goal context
  7408 (which is now passed through the inductive cases);
  7409 
  7410 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7411 \<gg> to \<ggreater>;
  7412 
  7413 
  7414 *** Document preparation ***
  7415 
  7416 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7417 available: are "it" for near math-mode best-style output, "sl" for
  7418 slanted text style, and "tt" for plain type-writer; if no
  7419 \isabellestyle command is given, output is according to slanted
  7420 type-writer);
  7421 
  7422 * support sub/super scripts (for single symbols only), input syntax is
  7423 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7424 
  7425 * some more standard symbols; see Appendix A of the system manual for
  7426 the complete list of symbols defined in isabellesym.sty;
  7427 
  7428 * improved isabelle style files; more abstract symbol implementation
  7429 (should now use \isamath{...} and \isatext{...} in custom symbol
  7430 definitions);
  7431 
  7432 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  7433 state; Note that presentation of goal states does not conform to
  7434 actual human-readable proof documents.  Please do not include goal
  7435 states into document output unless you really know what you are doing!
  7436 
  7437 * proper indentation of antiquoted output with proportional LaTeX
  7438 fonts;
  7439 
  7440 * no_document ML operator temporarily disables LaTeX document
  7441 generation;
  7442 
  7443 * isatool unsymbolize tunes sources for plain ASCII communication;
  7444 
  7445 
  7446 *** Isar ***
  7447 
  7448 * Pure: Isar now suffers initial goal statements to contain unbound
  7449 schematic variables (this does not conform to actual readable proof
  7450 documents, due to unpredictable outcome and non-compositional proof
  7451 checking); users who know what they are doing may use schematic goals
  7452 for Prolog-style synthesis of proven results;
  7453 
  7454 * Pure: assumption method (an implicit finishing) now handles actual
  7455 rules as well;
  7456 
  7457 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  7458 initial goal, declare "that" only as Pure intro (only for single
  7459 steps); the "that" rule assumption may now be involved in implicit
  7460 finishing, thus ".." becomes a feasible for trivial obtains;
  7461 
  7462 * Pure: default proof step now includes 'intro_classes'; thus trivial
  7463 instance proofs may be performed by "..";
  7464 
  7465 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  7466 statements as well;
  7467 
  7468 * Pure: more robust selection of calculational rules;
  7469 
  7470 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  7471 rule (as well as the assumption rule);
  7472 
  7473 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  7474 lemmas, using the graph browser tool;
  7475 
  7476 * Pure: predict failure of "show" in interactive mode;
  7477 
  7478 * Pure: 'thms_containing' now takes actual terms as arguments;
  7479 
  7480 * HOL: improved method 'induct' --- now handles non-atomic goals
  7481 (potential INCOMPATIBILITY); tuned error handling;
  7482 
  7483 * HOL: cases and induct rules now provide explicit hints about the
  7484 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  7485 any remaining facts are inserted into the goal verbatim;
  7486 
  7487 * HOL: local contexts (aka cases) may now contain term bindings as
  7488 well; the 'cases' and 'induct' methods new provide a ?case binding for
  7489 the result to be shown in each case;
  7490 
  7491 * HOL: added 'recdef_tc' command;
  7492 
  7493 * isatool convert assists in eliminating legacy ML scripts;
  7494 
  7495 
  7496 *** HOL ***
  7497 
  7498 * HOL/Library: a collection of generic theories to be used together
  7499 with main HOL; the theory loader path already includes this directory
  7500 by default; the following existing theories have been moved here:
  7501 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  7502 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  7503 
  7504 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  7505 modelling and verification task performed in Isabelle/HOL +
  7506 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  7507 
  7508 * HOL/Algebra: special summation operator SUM no longer exists, it has
  7509 been replaced by setsum; infix 'assoc' now has priority 50 (like
  7510 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  7511 'domain', this makes the theory consistent with mathematical
  7512 literature;
  7513 
  7514 * HOL basics: added overloaded operations "inverse" and "divide"
  7515 (infix "/"), syntax for generic "abs" operation, generic summation
  7516 operator \<Sum>;
  7517 
  7518 * HOL/typedef: simplified package, provide more useful rules (see also
  7519 HOL/subset.thy);
  7520 
  7521 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  7522 now expressed as a proper nested rule (old-style tactic scripts may
  7523 require atomize_strip_tac to cope with non-atomic premises);
  7524 
  7525 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  7526 to "split_conv" (old name still available for compatibility);
  7527 
  7528 * HOL: improved concrete syntax for strings (e.g. allows translation
  7529 rules with string literals);
  7530 
  7531 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  7532  and Fleuriot's mechanization of analysis, including the transcendental
  7533  functions for the reals;
  7534 
  7535 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  7536 
  7537 
  7538 *** CTT ***
  7539 
  7540 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  7541 "lam" is displayed as TWO lambda-symbols
  7542 
  7543 * CTT: theory Main now available, containing everything (that is, Bool
  7544 and Arith);
  7545 
  7546 
  7547 *** General ***
  7548 
  7549 * Pure: the Simplifier has been implemented properly as a derived rule
  7550 outside of the actual kernel (at last!); the overall performance
  7551 penalty in practical applications is about 50%, while reliability of
  7552 the Isabelle inference kernel has been greatly improved;
  7553 
  7554 * print modes "brackets" and "no_brackets" control output of nested =>
  7555 (types) and ==> (props); the default behaviour is "brackets";
  7556 
  7557 * Provers: fast_tac (and friends) now handle actual object-logic rules
  7558 as assumptions as well;
  7559 
  7560 * system: support Poly/ML 4.0;
  7561 
  7562 * system: isatool install handles KDE version 1 or 2;
  7563 
  7564 
  7565 
  7566 New in Isabelle99-1 (October 2000)
  7567 ----------------------------------
  7568 
  7569 *** Overview of INCOMPATIBILITIES ***
  7570 
  7571 * HOL: simplification of natural numbers is much changed; to partly
  7572 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  7573 issue the following ML commands:
  7574 
  7575   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  7576   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  7577 
  7578 * HOL: simplification no longer dives into case-expressions; this is
  7579 controlled by "t.weak_case_cong" for each datatype t;
  7580 
  7581 * HOL: nat_less_induct renamed to less_induct;
  7582 
  7583 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  7584 fixsome to patch .thy and .ML sources automatically;
  7585 
  7586   select_equality  -> some_equality
  7587   select_eq_Ex     -> some_eq_ex
  7588   selectI2EX       -> someI2_ex
  7589   selectI2         -> someI2
  7590   selectI          -> someI
  7591   select1_equality -> some1_equality
  7592   Eps_sym_eq       -> some_sym_eq_trivial
  7593   Eps_eq           -> some_eq_trivial
  7594 
  7595 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  7596 
  7597 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  7598 instead);
  7599 
  7600 * HOL: the recursion equations generated by 'recdef' are now called
  7601 f.simps instead of f.rules;
  7602 
  7603 * HOL: qed_spec_mp now also handles bounded ALL as well;
  7604 
  7605 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  7606 sometimes be needed;
  7607 
  7608 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  7609 
  7610 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  7611 
  7612 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  7613 product is now "<*>" instead of "Times"; the lexicographic product is
  7614 now "<*lex*>" instead of "**";
  7615 
  7616 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  7617 of main HOL, but was unused); better use HOL's datatype package;
  7618 
  7619 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  7620 the old syntax may be recovered as follows:
  7621 
  7622   syntax (symbols)
  7623     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  7624       (infixl "\\<oplus>" 100)
  7625 
  7626 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7627 
  7628 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  7629 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  7630 internally;
  7631 
  7632 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  7633 changed from A/r to A//r;
  7634 
  7635 * ZF: new treatment of arithmetic (nat & int) may break some old
  7636 proofs;
  7637 
  7638 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  7639 rulify -> rule_format, elimify -> elim_format, ...);
  7640 
  7641 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7642 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  7643 should have to change intro!! to intro? only); replaced "delrule" by
  7644 "rule del";
  7645 
  7646 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  7647 
  7648 * Provers: strengthened force_tac by using new first_best_tac;
  7649 
  7650 * LaTeX document preparation: several changes of isabelle.sty (see
  7651 lib/texinputs);
  7652 
  7653 
  7654 *** Document preparation ***
  7655 
  7656 * formal comments (text blocks etc.) in new-style theories may now
  7657 contain antiquotations of thm/prop/term/typ/text to be presented
  7658 according to latex print mode; concrete syntax is like this:
  7659 @{term[show_types] "f(x) = a + x"};
  7660 
  7661 * isatool mkdir provides easy setup of Isabelle session directories,
  7662 including proper document sources;
  7663 
  7664 * generated LaTeX sources are now deleted after successful run
  7665 (isatool document -c); may retain a copy somewhere else via -D option
  7666 of isatool usedir;
  7667 
  7668 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  7669 style files, achieving self-contained LaTeX sources and simplifying
  7670 LaTeX debugging;
  7671 
  7672 * old-style theories now produce (crude) LaTeX output as well;
  7673 
  7674 * browser info session directories are now self-contained (may be put
  7675 on WWW server seperately); improved graphs of nested sessions; removed
  7676 graph for 'all sessions';
  7677 
  7678 * several improvements in isabelle style files; \isabellestyle{it}
  7679 produces fake math mode output; \isamarkupheader is now \section by
  7680 default; see lib/texinputs/isabelle.sty etc.;
  7681 
  7682 
  7683 *** Isar ***
  7684 
  7685 * Isar/Pure: local results and corresponding term bindings are now
  7686 subject to Hindley-Milner polymorphism (similar to ML); this
  7687 accommodates incremental type-inference very nicely;
  7688 
  7689 * Isar/Pure: new derived language element 'obtain' supports
  7690 generalized existence reasoning;
  7691 
  7692 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  7693 support accumulation of results, without applying any rules yet;
  7694 useful to collect intermediate results without explicit name
  7695 references, and for use with transitivity rules with more than 2
  7696 premises;
  7697 
  7698 * Isar/Pure: scalable support for case-analysis type proofs: new
  7699 'case' language element refers to local contexts symbolically, as
  7700 produced by certain proof methods; internally, case names are attached
  7701 to theorems as "tags";
  7702 
  7703 * Isar/Pure: theory command 'hide' removes declarations from
  7704 class/type/const name spaces;
  7705 
  7706 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  7707 indicate potential overloading;
  7708 
  7709 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  7710 
  7711 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  7712 "{a,b,c}" instead of {a,b,c};
  7713 
  7714 * Isar/Pure now provides its own version of intro/elim/dest
  7715 attributes; useful for building new logics, but beware of confusion
  7716 with the version in Provers/classical;
  7717 
  7718 * Isar/Pure: the local context of (non-atomic) goals is provided via
  7719 case name 'antecedent';
  7720 
  7721 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  7722 to the current context is now done automatically);
  7723 
  7724 * Isar/Pure: theory command 'method_setup' provides a simple interface
  7725 for definining proof methods in ML;
  7726 
  7727 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7728 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  7729 most cases, one should have to change intro!! to intro? only);
  7730 replaced "delrule" by "rule del";
  7731 
  7732 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  7733 'symmetric' attribute (the latter supercedes [RS sym]);
  7734 
  7735 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  7736 method modifier); 'simp' method: 'only:' modifier removes loopers as
  7737 well (including splits);
  7738 
  7739 * Isar/Provers: Simplifier and Classical methods now support all kind
  7740 of modifiers used in the past, including 'cong', 'iff', etc.
  7741 
  7742 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  7743 of Simplifier and Classical reasoner);
  7744 
  7745 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  7746 now support named cases; major packages (inductive, datatype, primrec,
  7747 recdef) support case names and properly name parameters;
  7748 
  7749 * Isar/HOL: new transitivity rules for substitution in inequalities --
  7750 monotonicity conditions are extracted to be proven at end of
  7751 calculations;
  7752 
  7753 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  7754 method anyway;
  7755 
  7756 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  7757 split_if split_if_asm; datatype package provides theorems foo.splits =
  7758 foo.split foo.split_asm for each datatype;
  7759 
  7760 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  7761 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  7762 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  7763 use "(cases (simplified))" method in proper proof texts);
  7764 
  7765 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  7766 
  7767 * Isar: names of theorems etc. may be natural numbers as well;
  7768 
  7769 * Isar: 'pr' command: optional arguments for goals_limit and
  7770 ProofContext.prems_limit; no longer prints theory contexts, but only
  7771 proof states;
  7772 
  7773 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  7774 additional print modes to be specified; e.g. "pr(latex)" will print
  7775 proof state according to the Isabelle LaTeX style;
  7776 
  7777 * Isar: improved support for emulating tactic scripts, including proof
  7778 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  7779 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  7780 (for HOL datatypes);
  7781 
  7782 * Isar: simplified (more robust) goal selection of proof methods: 1st
  7783 goal, all goals, or explicit goal specifier (tactic emulation); thus
  7784 'proof method scripts' have to be in depth-first order;
  7785 
  7786 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  7787 
  7788 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  7789 should instead use individual commands for printing items
  7790 (print_commands, print_methods etc.);
  7791 
  7792 * Isar: added 'nothing' --- the empty list of theorems;
  7793 
  7794 
  7795 *** HOL ***
  7796 
  7797 * HOL/MicroJava: formalization of a fragment of Java, together with a
  7798 corresponding virtual machine and a specification of its bytecode
  7799 verifier and a lightweight bytecode verifier, including proofs of
  7800 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  7801 Cornelia Pusch (see also the homepage of project Bali at
  7802 http://isabelle.in.tum.de/Bali/);
  7803 
  7804 * HOL/Algebra: new theory of rings and univariate polynomials, by
  7805 Clemens Ballarin;
  7806 
  7807 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  7808 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  7809 Rasmussen;
  7810 
  7811 * HOL/Lattice: fundamental concepts of lattice theory and order
  7812 structures, including duals, properties of bounds versus algebraic
  7813 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  7814 Theorem for complete lattices etc.; may also serve as a demonstration
  7815 for abstract algebraic reasoning using axiomatic type classes, and
  7816 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  7817 
  7818 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  7819 von Oheimb;
  7820 
  7821 * HOL/IMPP: extension of IMP with local variables and mutually
  7822 recursive procedures, by David von Oheimb;
  7823 
  7824 * HOL/Lambda: converted into new-style theory and document;
  7825 
  7826 * HOL/ex/Multiquote: example of multiple nested quotations and
  7827 anti-quotations -- basically a generalized version of de-Bruijn
  7828 representation; very useful in avoiding lifting of operations;
  7829 
  7830 * HOL/record: added general record equality rule to simpset; fixed
  7831 select-update simplification procedure to handle extended records as
  7832 well; admit "r" as field name;
  7833 
  7834 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  7835 other numeric types and also as the identity of groups, rings, etc.;
  7836 
  7837 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  7838 Types nat and int belong to this axclass;
  7839 
  7840 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  7841    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  7842    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  7843   two terms #m*u and #n*u are replaced by #(m+n)*u
  7844     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  7845   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  7846     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  7847 
  7848 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  7849 powerful prover for predicate logic but knows nothing of clasets; see
  7850 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  7851 
  7852 * HOL: new version of "case_tac" subsumes both boolean case split and
  7853 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  7854 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  7855 
  7856 * HOL: simplification no longer dives into case-expressions: only the
  7857 selector expression is simplified, but not the remaining arms; to
  7858 enable full simplification of case-expressions for datatype t, you may
  7859 remove t.weak_case_cong from the simpset, either globally (Delcongs
  7860 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  7861 
  7862 * HOL/recdef: the recursion equations generated by 'recdef' for
  7863 function 'f' are now called f.simps instead of f.rules; if all
  7864 termination conditions are proved automatically, these simplification
  7865 rules are added to the simpset, as in primrec; rules may be named
  7866 individually as well, resulting in a separate list of theorems for
  7867 each equation;
  7868 
  7869 * HOL/While is a new theory that provides a while-combinator. It
  7870 permits the definition of tail-recursive functions without the
  7871 provision of a termination measure. The latter is necessary once the
  7872 invariant proof rule for while is applied.
  7873 
  7874 * HOL: new (overloaded) notation for the set of elements below/above
  7875 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7876 
  7877 * HOL: theorems impI, allI, ballI bound as "strip";
  7878 
  7879 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7880 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7881 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7882 
  7883 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7884 
  7885 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7886 main HOL, but was unused);
  7887 
  7888 * HOL: fewer consts declared as global (e.g. have to refer to
  7889 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7890 
  7891 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7892 in case of overlap with user translations (e.g. judgements over
  7893 tuples); (note that the underlying logical represenation is still
  7894 bogus);
  7895 
  7896 
  7897 *** ZF ***
  7898 
  7899 * ZF: simplification automatically cancels common terms in arithmetic
  7900 expressions over nat and int;
  7901 
  7902 * ZF: new treatment of nat to minimize type-checking: all operators
  7903 coerce their operands to a natural number using the function natify,
  7904 making the algebraic laws unconditional;
  7905 
  7906 * ZF: as above, for int: operators coerce their operands to an integer
  7907 using the function intify;
  7908 
  7909 * ZF: the integer library now contains many of the usual laws for the
  7910 orderings, including $<=, and monotonicity laws for $+ and $*;
  7911 
  7912 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7913 simplification;
  7914 
  7915 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7916 to the simplifier and classical reasoner simultaneously;
  7917 
  7918 
  7919 *** General ***
  7920 
  7921 * Provers: blast_tac now handles actual object-logic rules as
  7922 assumptions; note that auto_tac uses blast_tac internally as well;
  7923 
  7924 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7925 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7926 
  7927 * Provers: delrules now handles destruct rules as well (no longer need
  7928 explicit make_elim);
  7929 
  7930 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7931   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7932 use instead the strong form,
  7933   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7934 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7935 from destruct-rules;
  7936 
  7937 * Provers: Simplifier.easy_setup provides a fast path to basic
  7938 Simplifier setup for new object-logics;
  7939 
  7940 * Pure: AST translation rules no longer require constant head on LHS;
  7941 
  7942 * Pure: improved name spaces: ambiguous output is qualified; support
  7943 for hiding of names;
  7944 
  7945 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7946 XSYMBOL_HOME; no longer need to do manual configuration in most
  7947 situations;
  7948 
  7949 * system: compression of ML heaps images may now be controlled via -c
  7950 option of isabelle and isatool usedir (currently only observed by
  7951 Poly/ML);
  7952 
  7953 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7954 useful for remote X11);
  7955 
  7956 * system: provide TAGS file for Isabelle sources;
  7957 
  7958 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7959 order;
  7960 
  7961 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7962 timing flag supersedes proof_timing and Toplevel.trace;
  7963 
  7964 * ML: new combinators |>> and |>>> for incremental transformations
  7965 with secondary results (e.g. certain theory extensions):
  7966 
  7967 * ML: PureThy.add_defs gets additional argument to indicate potential
  7968 overloading (usually false);
  7969 
  7970 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7971 results;
  7972 
  7973 
  7974 
  7975 New in Isabelle99 (October 1999)
  7976 --------------------------------
  7977 
  7978 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7979 
  7980 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7981 are no longer simplified.  (This allows the simplifier to unfold recursive
  7982 functional programs.)  To restore the old behaviour, declare
  7983 
  7984     Delcongs [if_weak_cong];
  7985 
  7986 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7987 complement;
  7988 
  7989 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7990 
  7991 * HOL/datatype: mutual_induct_tac no longer exists --
  7992   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7993 
  7994 * HOL/typedef: fixed type inference for representing set; type
  7995 arguments now have to occur explicitly on the rhs as type constraints;
  7996 
  7997 * ZF: The con_defs part of an inductive definition may no longer refer
  7998 to constants declared in the same theory;
  7999 
  8000 * HOL, ZF: the function mk_cases, generated by the inductive
  8001 definition package, has lost an argument.  To simplify its result, it
  8002 uses the default simpset instead of a supplied list of theorems.
  8003 
  8004 * HOL/List: the constructors of type list are now Nil and Cons;
  8005 
  8006 * Simplifier: the type of the infix ML functions
  8007         setSSolver addSSolver setSolver addSolver
  8008 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  8009 for packaging solvers. A solver is created via
  8010         mk_solver: string -> (thm list -> int -> tactic) -> solver
  8011 where the string argument is only a comment.
  8012 
  8013 
  8014 *** Proof tools ***
  8015 
  8016 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  8017 decision procedure for linear arithmetic. Currently it is used for
  8018 types `nat', `int', and `real' in HOL (see below); it can, should and
  8019 will be instantiated for other types and logics as well.
  8020 
  8021 * The simplifier now accepts rewrite rules with flexible heads, eg
  8022      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  8023   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  8024   matching.
  8025 
  8026 
  8027 *** General ***
  8028 
  8029 * New Isabelle/Isar subsystem provides an alternative to traditional
  8030 tactical theorem proving; together with the ProofGeneral/isar user
  8031 interface it offers an interactive environment for developing human
  8032 readable proof documents (Isar == Intelligible semi-automated
  8033 reasoning); for further information see isatool doc isar-ref,
  8034 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  8035 
  8036 * improved and simplified presentation of theories: better HTML markup
  8037 (including colors), graph views in several sizes; isatool usedir now
  8038 provides a proper interface for user theories (via -P option); actual
  8039 document preparation based on (PDF)LaTeX is available as well (for
  8040 new-style theories only); see isatool doc system for more information;
  8041 
  8042 * native support for Proof General, both for classic Isabelle and
  8043 Isabelle/Isar;
  8044 
  8045 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  8046 using the graph browser tool;
  8047 
  8048 * Isabelle manuals now also available as PDF;
  8049 
  8050 * theory loader rewritten from scratch (may not be fully
  8051 bug-compatible); old loadpath variable has been replaced by show_path,
  8052 add_path, del_path, reset_path functions; new operations such as
  8053 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  8054 isatool doc ref);
  8055 
  8056 * improved isatool install: option -k creates KDE application icon,
  8057 option -p DIR installs standalone binaries;
  8058 
  8059 * added ML_PLATFORM setting (useful for cross-platform installations);
  8060 more robust handling of platform specific ML images for SML/NJ;
  8061 
  8062 * the settings environment is now statically scoped, i.e. it is never
  8063 created again in sub-processes invoked from isabelle, isatool, or
  8064 Isabelle;
  8065 
  8066 * path element specification '~~' refers to '$ISABELLE_HOME';
  8067 
  8068 * in locales, the "assumes" and "defines" parts may be omitted if
  8069 empty;
  8070 
  8071 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  8072 long arrows);
  8073 
  8074 * new print_mode "HTML";
  8075 
  8076 * new flag show_tags controls display of tags of theorems (which are
  8077 basically just comments that may be attached by some tools);
  8078 
  8079 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  8080 mode and goal output format:
  8081 
  8082 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  8083 244c244
  8084 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  8085 ---
  8086 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  8087 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  8088 181c181
  8089 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  8090 ---
  8091 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  8092 
  8093 * function bind_thms stores lists of theorems (cf. bind_thm);
  8094 
  8095 * new shorthand tactics ftac, eatac, datac, fatac;
  8096 
  8097 * qed (and friends) now accept "" as result name; in that case the
  8098 theorem is not stored, but proper checks and presentation of the
  8099 result still apply;
  8100 
  8101 * theorem database now also indexes constants "Trueprop", "all",
  8102 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  8103 
  8104 
  8105 *** HOL ***
  8106 
  8107 ** HOL arithmetic **
  8108 
  8109 * There are now decision procedures for linear arithmetic over nat and
  8110 int:
  8111 
  8112 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  8113 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  8114 are treated as atomic; subformulae not involving type `nat' or `int'
  8115 are ignored; quantified subformulae are ignored unless they are
  8116 positive universal or negative existential. The tactic has to be
  8117 invoked by hand and can be a little bit slow. In particular, the
  8118 running time is exponential in the number of occurrences of `min' and
  8119 `max', and `-' on `nat'.
  8120 
  8121 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  8122 (negated) (in)equalities among the premises and the conclusion into
  8123 account (i.e. no compound formulae) and does not know about `min' and
  8124 `max', and `-' on `nat'. It is fast and is used automatically by the
  8125 simplifier.
  8126 
  8127 NB: At the moment, these decision procedures do not cope with mixed
  8128 nat/int formulae where the two parts interact, such as `m < n ==>
  8129 int(m) < int(n)'.
  8130 
  8131 * HOL/Numeral provides a generic theory of numerals (encoded
  8132 efficiently as bit strings); setup for types nat/int/real is in place;
  8133 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  8134 int, existing theories and proof scripts may require a few additional
  8135 type constraints;
  8136 
  8137 * integer division and remainder can now be performed on constant
  8138 arguments;
  8139 
  8140 * many properties of integer multiplication, division and remainder
  8141 are now available;
  8142 
  8143 * An interface to the Stanford Validity Checker (SVC) is available through the
  8144 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  8145 are proved automatically.  SVC must be installed separately, and its results
  8146 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  8147 invocation of the underlying oracle).  For SVC see
  8148   http://verify.stanford.edu/SVC
  8149 
  8150 * IsaMakefile: the HOL-Real target now builds an actual image;
  8151 
  8152 
  8153 ** HOL misc **
  8154 
  8155 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  8156 (in Isabelle/Isar) -- by Gertrud Bauer;
  8157 
  8158 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  8159 analysis for assembly languages with subtypes;
  8160 
  8161 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  8162 -- avoids syntactic ambiguities and treats state, transition, and
  8163 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  8164 changed syntax and (many) tactics;
  8165 
  8166 * HOL/inductive: Now also handles more general introduction rules such
  8167   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  8168   theorems are now maintained within the theory (maintained via the
  8169   "mono" attribute);
  8170 
  8171 * HOL/datatype: Now also handles arbitrarily branching datatypes
  8172   (using function types) such as
  8173 
  8174   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  8175 
  8176 * HOL/record: record_simproc (part of the default simpset) takes care
  8177 of selectors applied to updated records; record_split_tac is no longer
  8178 part of the default claset; update_defs may now be removed from the
  8179 simpset in many cases; COMPATIBILITY: old behavior achieved by
  8180 
  8181   claset_ref () := claset() addSWrapper record_split_wrapper;
  8182   Delsimprocs [record_simproc]
  8183 
  8184 * HOL/typedef: fixed type inference for representing set; type
  8185 arguments now have to occur explicitly on the rhs as type constraints;
  8186 
  8187 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  8188 names rather than an ML expression;
  8189 
  8190 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  8191 supplied later.  Program schemes can be defined, such as
  8192     "While B C s = (if B s then While B C (C s) else s)"
  8193 where the well-founded relation can be chosen after B and C have been given.
  8194 
  8195 * HOL/List: the constructors of type list are now Nil and Cons;
  8196 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  8197 course, ML tools referring to List.list.op # etc. have to be adapted;
  8198 
  8199 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  8200 disabled by default; run isabelle with option -m HOL to get back to
  8201 the original Gordon/HOL-style output;
  8202 
  8203 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  8204 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  8205 
  8206 * HOL basic syntax simplified (more orthogonal): all variants of
  8207 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  8208 Eps operator is provided as well: "SOME x. P[x]";
  8209 
  8210 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  8211 
  8212 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  8213 thus available for user theories;
  8214 
  8215 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  8216 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  8217 time;
  8218 
  8219 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  8220 several times and then mp;
  8221 
  8222 
  8223 *** LK ***
  8224 
  8225 * the notation <<...>> is now available as a notation for sequences of
  8226 formulas;
  8227 
  8228 * the simplifier is now installed
  8229 
  8230 * the axiom system has been generalized (thanks to Soren Heilmann)
  8231 
  8232 * the classical reasoner now has a default rule database
  8233 
  8234 
  8235 *** ZF ***
  8236 
  8237 * new primrec section allows primitive recursive functions to be given
  8238 directly (as in HOL) over datatypes and the natural numbers;
  8239 
  8240 * new tactics induct_tac and exhaust_tac for induction (or case
  8241 analysis) over datatypes and the natural numbers;
  8242 
  8243 * the datatype declaration of type T now defines the recursor T_rec;
  8244 
  8245 * simplification automatically does freeness reasoning for datatype
  8246 constructors;
  8247 
  8248 * automatic type-inference, with AddTCs command to insert new
  8249 type-checking rules;
  8250 
  8251 * datatype introduction rules are now added as Safe Introduction rules
  8252 to the claset;
  8253 
  8254 * the syntax "if P then x else y" is now available in addition to
  8255 if(P,x,y);
  8256 
  8257 
  8258 *** Internal programming interfaces ***
  8259 
  8260 * tuned simplifier trace output; new flag debug_simp;
  8261 
  8262 * structures Vartab / Termtab (instances of TableFun) offer efficient
  8263 tables indexed by indexname_ord / term_ord (compatible with aconv);
  8264 
  8265 * AxClass.axclass_tac lost the theory argument;
  8266 
  8267 * tuned current_goals_markers semantics: begin / end goal avoids
  8268 printing empty lines;
  8269 
  8270 * removed prs and prs_fn hook, which was broken because it did not
  8271 include \n in its semantics, forcing writeln to add one
  8272 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  8273 string -> unit if you really want to output text without newline;
  8274 
  8275 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  8276 plain output, interface builders may have to enable 'isabelle_font'
  8277 mode to get Isabelle font glyphs as before;
  8278 
  8279 * refined token_translation interface; INCOMPATIBILITY: output length
  8280 now of type real instead of int;
  8281 
  8282 * theory loader actions may be traced via new ThyInfo.add_hook
  8283 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8284 your own database of information attached to *whole* theories -- as
  8285 opposed to intra-theory data slots offered via TheoryDataFun;
  8286 
  8287 * proper handling of dangling sort hypotheses (at last!);
  8288 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8289 extra sort hypotheses that can be witnessed from the type signature;
  8290 the force_strip_shyps flag is gone, any remaining shyps are simply
  8291 left in the theorem (with a warning issued by strip_shyps_warning);
  8292 
  8293 
  8294 
  8295 New in Isabelle98-1 (October 1998)
  8296 ----------------------------------
  8297 
  8298 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8299 
  8300 * several changes of automated proof tools;
  8301 
  8302 * HOL: major changes to the inductive and datatype packages, including
  8303 some minor incompatibilities of theory syntax;
  8304 
  8305 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8306 called `inj_on';
  8307 
  8308 * HOL: removed duplicate thms in Arith:
  8309   less_imp_add_less  should be replaced by  trans_less_add1
  8310   le_imp_add_le      should be replaced by  trans_le_add1
  8311 
  8312 * HOL: unary minus is now overloaded (new type constraints may be
  8313 required);
  8314 
  8315 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8316 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8317 now taken as an integer constant.
  8318 
  8319 * Pure: ML function 'theory_of' renamed to 'theory';
  8320 
  8321 
  8322 *** Proof tools ***
  8323 
  8324 * Simplifier:
  8325   1. Asm_full_simp_tac is now more aggressive.
  8326      1. It will sometimes reorient premises if that increases their power to
  8327         simplify.
  8328      2. It does no longer proceed strictly from left to right but may also
  8329         rotate premises to achieve further simplification.
  8330      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8331      old Asm_full_simp_tac in that it does not rotate premises.
  8332   2. The simplifier now knows a little bit about nat-arithmetic.
  8333 
  8334 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8335 allows for selected deletion of wrappers, by introduction of names for
  8336 wrapper functionals.  This implies that addbefore, addSbefore,
  8337 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8338 and that adding two tactics with the same name overwrites the first
  8339 one (emitting a warning).
  8340   type wrapper = (int -> tactic) -> (int -> tactic)
  8341   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8342   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8343   delWrapper, delSWrapper: claset *  string            -> claset
  8344   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8345 
  8346 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8347 semantics; addbefore now affects only the unsafe part of step_tac
  8348 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8349 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8350 by Force_tac;
  8351 
  8352 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8353 compWrapper; added safe wrapper (and access functions for it);
  8354 
  8355 * HOL/split_all_tac is now much faster and fails if there is nothing
  8356 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8357 and the names of the automatically generated variables have changed.
  8358 split_all_tac has moved within claset() from unsafe wrappers to safe
  8359 wrappers, which means that !!-bound variables are split much more
  8360 aggressively, and safe_tac and clarify_tac now split such variables.
  8361 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8362 Note: the same holds for record_split_tac, which does the job of
  8363 split_all_tac for record fields.
  8364 
  8365 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8366 permanently to the default simpset using Addsplits just like
  8367 Addsimps. They can be removed via Delsplits just like
  8368 Delsimps. Lower-case versions are also available.
  8369 
  8370 * HOL/Simplifier: The rule split_if is now part of the default
  8371 simpset. This means that the simplifier will eliminate all occurrences
  8372 of if-then-else in the conclusion of a goal. To prevent this, you can
  8373 either remove split_if completely from the default simpset by
  8374 `Delsplits [split_if]' or remove it in a specific call of the
  8375 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8376 other case splitting rules to/from the default simpset: every datatype
  8377 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8378 t is the name of the datatype).
  8379 
  8380 * Classical reasoner / Simplifier combination: new force_tac (and
  8381 derivatives Force_tac, force) combines rewriting and classical
  8382 reasoning (and whatever other tools) similarly to auto_tac, but is
  8383 aimed to solve the given subgoal completely.
  8384 
  8385 
  8386 *** General ***
  8387 
  8388 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8389 and `goalw': the theory is no longer needed as an explicit argument -
  8390 the current theory context is used; assumptions are no longer returned
  8391 at the ML-level unless one of them starts with ==> or !!; it is
  8392 recommended to convert to these new commands using isatool fixgoal
  8393 (backup your sources first!);
  8394 
  8395 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8396 the current theory context, and 'theory' to lookup stored theories;
  8397 
  8398 * new theory section 'locale' for declaring constants, assumptions and
  8399 definitions that have local scope;
  8400 
  8401 * new theory section 'nonterminals' for purely syntactic types;
  8402 
  8403 * new theory section 'setup' for generic ML setup functions
  8404 (e.g. package initialization);
  8405 
  8406 * the distribution now includes Isabelle icons: see
  8407 lib/logo/isabelle-{small,tiny}.xpm;
  8408 
  8409 * isatool install - install binaries with absolute references to
  8410 ISABELLE_HOME/bin;
  8411 
  8412 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8413 
  8414 * print mode 'emacs' reserved for Isamode;
  8415 
  8416 * support multiple print (ast) translations per constant name;
  8417 
  8418 * theorems involving oracles are now printed with a suffixed [!];
  8419 
  8420 
  8421 *** HOL ***
  8422 
  8423 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8424 
  8425 * HOL/inductive package reorganized and improved: now supports mutual
  8426 definitions such as
  8427 
  8428   inductive EVEN ODD
  8429     intrs
  8430       null "0 : EVEN"
  8431       oddI "n : EVEN ==> Suc n : ODD"
  8432       evenI "n : ODD ==> Suc n : EVEN"
  8433 
  8434 new theorem list "elims" contains an elimination rule for each of the
  8435 recursive sets; inductive definitions now handle disjunctive premises
  8436 correctly (also ZF);
  8437 
  8438 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  8439 "mutual_induct" no longer exists - the induction rule is always
  8440 contained in "induct";
  8441 
  8442 
  8443 * HOL/datatype package re-implemented and greatly improved: now
  8444 supports mutually recursive datatypes such as
  8445 
  8446   datatype
  8447     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  8448             | SUM ('a aexp) ('a aexp)
  8449             | DIFF ('a aexp) ('a aexp)
  8450             | NUM 'a
  8451   and
  8452     'a bexp = LESS ('a aexp) ('a aexp)
  8453             | AND ('a bexp) ('a bexp)
  8454             | OR ('a bexp) ('a bexp)
  8455 
  8456 as well as indirectly recursive datatypes such as
  8457 
  8458   datatype
  8459     ('a, 'b) term = Var 'a
  8460                   | App 'b ((('a, 'b) term) list)
  8461 
  8462 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  8463 induction on mutually / indirectly recursive datatypes.
  8464 
  8465 Primrec equations are now stored in theory and can be accessed via
  8466 <function_name>.simps.
  8467 
  8468 INCOMPATIBILITIES:
  8469 
  8470   - Theories using datatypes must now have theory Datatype as an
  8471     ancestor.
  8472   - The specific <typename>.induct_tac no longer exists - use the
  8473     generic induct_tac instead.
  8474   - natE has been renamed to nat.exhaust - use exhaust_tac
  8475     instead of res_inst_tac ... natE. Note that the variable
  8476     names in nat.exhaust differ from the names in natE, this
  8477     may cause some "fragile" proofs to fail.
  8478   - The theorems split_<typename>_case and split_<typename>_case_asm
  8479     have been renamed to <typename>.split and <typename>.split_asm.
  8480   - Since default sorts of type variables are now handled correctly,
  8481     some datatype definitions may have to be annotated with explicit
  8482     sort constraints.
  8483   - Primrec definitions no longer require function name and type
  8484     of recursive argument.
  8485 
  8486 Consider using isatool fixdatatype to adapt your theories and proof
  8487 scripts to the new package (backup your sources first!).
  8488 
  8489 
  8490 * HOL/record package: considerably improved implementation; now
  8491 includes concrete syntax for record types, terms, updates; theorems
  8492 for surjective pairing and splitting !!-bound record variables; proof
  8493 support is as follows:
  8494 
  8495   1) standard conversions (selectors or updates applied to record
  8496 constructor terms) are part of the standard simpset;
  8497 
  8498   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  8499 made part of standard simpset and claset via addIffs;
  8500 
  8501   3) a tactic for record field splitting (record_split_tac) is part of
  8502 the standard claset (addSWrapper);
  8503 
  8504 To get a better idea about these rules you may retrieve them via
  8505 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  8506 the name of your record type.
  8507 
  8508 The split tactic 3) conceptually simplifies by the following rule:
  8509 
  8510   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  8511 
  8512 Thus any record variable that is bound by meta-all will automatically
  8513 blow up into some record constructor term, consequently the
  8514 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  8515 solve record problems automatically.
  8516 
  8517 
  8518 * reorganized the main HOL image: HOL/Integ and String loaded by
  8519 default; theory Main includes everything;
  8520 
  8521 * automatic simplification of integer sums and comparisons, using cancellation;
  8522 
  8523 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  8524 
  8525 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  8526 
  8527 * many new identities for unions, intersections, set difference, etc.;
  8528 
  8529 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  8530 called split_if, split_split, split_sum_case and split_nat_case (to go
  8531 with add/delsplits);
  8532 
  8533 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  8534 (?x::unit) = (); this is made part of the default simpset, which COULD
  8535 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  8536 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  8537 unit_abs_eta_conv is added in order to counter the effect of
  8538 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  8539 %u.f();
  8540 
  8541 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  8542 makes more sense);
  8543 
  8544 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8545   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8546   disjointness reasoning but breaking a few old proofs.
  8547 
  8548 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  8549 to 'converse' from 'inverse' (for compatibility with ZF and some
  8550 literature);
  8551 
  8552 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  8553 the well-founded relation;
  8554 
  8555 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  8556     Compl A.  The "Compl" syntax remains available as input syntax for this
  8557     release ONLY.
  8558 
  8559 * HOL/Update: new theory of function updates:
  8560     f(a:=b) == %x. if x=a then b else f x
  8561 may also be iterated as in f(a:=b,c:=d,...);
  8562 
  8563 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  8564 
  8565 * HOL/List:
  8566   - new function list_update written xs[i:=v] that updates the i-th
  8567     list position. May also be iterated as in xs[i:=a,j:=b,...].
  8568   - new function `upt' written [i..j(] which generates the list
  8569     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  8570     bound write [i..j], which is a shorthand for [i..j+1(].
  8571   - new lexicographic orderings and corresponding wellfoundedness theorems.
  8572 
  8573 * HOL/Arith:
  8574   - removed 'pred' (predecessor) function;
  8575   - generalized some theorems about n-1;
  8576   - many new laws about "div" and "mod";
  8577   - new laws about greatest common divisors (see theory ex/Primes);
  8578 
  8579 * HOL/Relation: renamed the relational operator r^-1 "converse"
  8580 instead of "inverse";
  8581 
  8582 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  8583   of the multiset ordering;
  8584 
  8585 * directory HOL/Real: a construction of the reals using Dedekind cuts
  8586   (not included by default);
  8587 
  8588 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  8589 
  8590 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  8591   programs, i.e. different program variables may have different types.
  8592 
  8593 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8594   [previously, this check worked only if the rewrite rule was unconditional]
  8595   Now rew can involve either definitions or equalities (either == or =).
  8596 
  8597 
  8598 *** ZF ***
  8599 
  8600 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  8601   only the theorems proved on ZF.ML;
  8602 
  8603 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8604   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8605   disjointness reasoning but breaking a few old proofs.
  8606 
  8607 * ZF/Update: new theory of function updates
  8608     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  8609   may also be iterated as in f(a:=b,c:=d,...);
  8610 
  8611 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  8612 
  8613 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8614   [previously, this check worked only if the rewrite rule was unconditional]
  8615   Now rew can involve either definitions or equalities (either == or =).
  8616 
  8617 * case_tac provided for compatibility with HOL
  8618     (like the old excluded_middle_tac, but with subgoals swapped)
  8619 
  8620 
  8621 *** Internal programming interfaces ***
  8622 
  8623 * Pure: several new basic modules made available for general use, see
  8624 also src/Pure/README;
  8625 
  8626 * improved the theory data mechanism to support encapsulation (data
  8627 kind name replaced by private Object.kind, acting as authorization
  8628 key); new type-safe user interface via functor TheoryDataFun; generic
  8629 print_data function becomes basically useless;
  8630 
  8631 * removed global_names compatibility flag -- all theory declarations
  8632 are qualified by default;
  8633 
  8634 * module Pure/Syntax now offers quote / antiquote translation
  8635 functions (useful for Hoare logic etc. with implicit dependencies);
  8636 see HOL/ex/Antiquote for an example use;
  8637 
  8638 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  8639 cterm -> thm;
  8640 
  8641 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  8642 subgoal;
  8643 
  8644 * Display.print_goals function moved to Locale.print_goals;
  8645 
  8646 * standard print function for goals supports current_goals_markers
  8647 variable for marking begin of proof, end of proof, start of goal; the
  8648 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  8649 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  8650 for example;
  8651 
  8652 
  8653 
  8654 New in Isabelle98 (January 1998)
  8655 --------------------------------
  8656 
  8657 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8658 
  8659 * changed lexical syntax of terms / types: dots made part of long
  8660 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  8661 
  8662 * simpset (and claset) reference variable replaced by functions
  8663 simpset / simpset_ref;
  8664 
  8665 * no longer supports theory aliases (via merge) and non-trivial
  8666 implicit merge of thms' signatures;
  8667 
  8668 * most internal names of constants changed due to qualified names;
  8669 
  8670 * changed Pure/Sequence interface (see Pure/seq.ML);
  8671 
  8672 
  8673 *** General Changes ***
  8674 
  8675 * hierachically structured name spaces (for consts, types, axms, thms
  8676 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  8677 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  8678 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  8679 long_names for fully qualified output names; NOTE: ML programs
  8680 (special tactics, packages etc.) referring to internal names may have
  8681 to be adapted to cope with fully qualified names; in case of severe
  8682 backward campatibility problems try setting 'global_names' at compile
  8683 time to have enrything declared within a flat name space; one may also
  8684 fine tune name declarations in theories via the 'global' and 'local'
  8685 section;
  8686 
  8687 * reimplemented the implicit simpset and claset using the new anytype
  8688 data filed in signatures; references simpset:simpset ref etc. are
  8689 replaced by functions simpset:unit->simpset and
  8690 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  8691 to patch your ML files accordingly;
  8692 
  8693 * HTML output now includes theory graph data for display with Java
  8694 applet or isatool browser; data generated automatically via isatool
  8695 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  8696 
  8697 * defs may now be conditional; improved rewrite_goals_tac to handle
  8698 conditional equations;
  8699 
  8700 * defs now admits additional type arguments, using TYPE('a) syntax;
  8701 
  8702 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  8703 creates a new theory node; implicit merge of thms' signatures is
  8704 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  8705 transfer:theory->thm->thm in (rare) cases;
  8706 
  8707 * improved handling of draft signatures / theories; draft thms (and
  8708 ctyps, cterms) are automatically promoted to real ones;
  8709 
  8710 * slightly changed interfaces for oracles: admit many per theory, named
  8711 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  8712 
  8713 * print_goals: optional output of const types (set show_consts and
  8714 show_types);
  8715 
  8716 * improved output of warnings (###) and errors (***);
  8717 
  8718 * subgoal_tac displays a warning if the new subgoal has type variables;
  8719 
  8720 * removed old README and Makefiles;
  8721 
  8722 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  8723 
  8724 * removed obsolete init_pps and init_database;
  8725 
  8726 * deleted the obsolete tactical STATE, which was declared by
  8727     fun STATE tacfun st = tacfun st st;
  8728 
  8729 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  8730 (which abbreviates $HOME);
  8731 
  8732 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  8733 use isatool fixseq to adapt your ML programs (this works for fully
  8734 qualified references to the Sequence structure only!);
  8735 
  8736 * use_thy no longer requires writable current directory; it always
  8737 reloads .ML *and* .thy file, if either one is out of date;
  8738 
  8739 
  8740 *** Classical Reasoner ***
  8741 
  8742 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  8743 tactics that use classical reasoning to simplify a subgoal without
  8744 splitting it into several subgoals;
  8745 
  8746 * Safe_tac: like safe_tac but uses the default claset;
  8747 
  8748 
  8749 *** Simplifier ***
  8750 
  8751 * added simplification meta rules:
  8752     (asm_)(full_)simplify: simpset -> thm -> thm;
  8753 
  8754 * simplifier.ML no longer part of Pure -- has to be loaded by object
  8755 logics (again);
  8756 
  8757 * added prems argument to simplification procedures;
  8758 
  8759 * HOL, FOL, ZF: added infix function `addsplits':
  8760   instead of `<simpset> setloop (split_tac <thms>)'
  8761   you can simply write `<simpset> addsplits <thms>'
  8762 
  8763 
  8764 *** Syntax ***
  8765 
  8766 * TYPE('a) syntax for type reflection terms;
  8767 
  8768 * no longer handles consts with name "" -- declare as 'syntax' instead;
  8769 
  8770 * pretty printer: changed order of mixfix annotation preference (again!);
  8771 
  8772 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  8773 
  8774 
  8775 *** HOL ***
  8776 
  8777 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8778   with `addloop' of the simplifier to faciliate case splitting in premises.
  8779 
  8780 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  8781 
  8782 * HOL/Auth: new protocol proofs including some for the Internet
  8783   protocol TLS;
  8784 
  8785 * HOL/Map: new theory of `maps' a la VDM;
  8786 
  8787 * HOL/simplifier: simplification procedures nat_cancel_sums for
  8788 cancelling out common nat summands from =, <, <= (in)equalities, or
  8789 differences; simplification procedures nat_cancel_factor for
  8790 cancelling common factor from =, <, <= (in)equalities over natural
  8791 sums; nat_cancel contains both kinds of procedures, it is installed by
  8792 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  8793 
  8794 * HOL/simplifier: terms of the form
  8795   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  8796   are rewritten to
  8797   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  8798   and those of the form
  8799   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  8800   are rewritten to
  8801   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  8802 
  8803 * HOL/datatype
  8804   Each datatype `t' now comes with a theorem `split_t_case' of the form
  8805 
  8806   P(t_case f1 ... fn x) =
  8807      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  8808         ...
  8809        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  8810      )
  8811 
  8812   and a theorem `split_t_case_asm' of the form
  8813 
  8814   P(t_case f1 ... fn x) =
  8815     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  8816         ...
  8817        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  8818      )
  8819   which can be added to a simpset via `addsplits'. The existing theorems
  8820   expand_list_case and expand_option_case have been renamed to
  8821   split_list_case and split_option_case.
  8822 
  8823 * HOL/Arithmetic:
  8824   - `pred n' is automatically converted to `n-1'.
  8825     Users are strongly encouraged not to use `pred' any longer,
  8826     because it will disappear altogether at some point.
  8827   - Users are strongly encouraged to write "0 < n" rather than
  8828     "n ~= 0". Theorems and proof tools have been modified towards this
  8829     `standard'.
  8830 
  8831 * HOL/Lists:
  8832   the function "set_of_list" has been renamed "set" (and its theorems too);
  8833   the function "nth" now takes its arguments in the reverse order and
  8834   has acquired the infix notation "!" as in "xs!n".
  8835 
  8836 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  8837 
  8838 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  8839   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  8840 
  8841 * HOL/record: extensible records with schematic structural subtyping
  8842 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  8843 still lacks various theorems and concrete record syntax;
  8844 
  8845 
  8846 *** HOLCF ***
  8847 
  8848 * removed "axioms" and "generated by" sections;
  8849 
  8850 * replaced "ops" section by extended "consts" section, which is capable of
  8851   handling the continuous function space "->" directly;
  8852 
  8853 * domain package:
  8854   . proves theorems immediately and stores them in the theory,
  8855   . creates hierachical name space,
  8856   . now uses normal mixfix annotations (instead of cinfix...),
  8857   . minor changes to some names and values (for consistency),
  8858   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  8859   . separator between mutual domain defs: changed "," to "and",
  8860   . improved handling of sort constraints;  now they have to
  8861     appear on the left-hand side of the equations only;
  8862 
  8863 * fixed LAM <x,y,zs>.b syntax;
  8864 
  8865 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  8866 adm (%x. P (t x)), where P is chainfinite and t continuous;
  8867 
  8868 
  8869 *** FOL and ZF ***
  8870 
  8871 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8872   with `addloop' of the simplifier to faciliate case splitting in premises.
  8873 
  8874 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8875 in HOL, they strip ALL and --> from proved theorems;
  8876 
  8877 
  8878 
  8879 New in Isabelle94-8 (May 1997)
  8880 ------------------------------
  8881 
  8882 *** General Changes ***
  8883 
  8884 * new utilities to build / run / maintain Isabelle etc. (in parts
  8885 still somewhat experimental); old Makefiles etc. still functional;
  8886 
  8887 * new 'Isabelle System Manual';
  8888 
  8889 * INSTALL text, together with ./configure and ./build scripts;
  8890 
  8891 * reimplemented type inference for greater efficiency, better error
  8892 messages and clean internal interface;
  8893 
  8894 * prlim command for dealing with lots of subgoals (an easier way of
  8895 setting goals_limit);
  8896 
  8897 
  8898 *** Syntax ***
  8899 
  8900 * supports alternative (named) syntax tables (parser and pretty
  8901 printer); internal interface is provided by add_modesyntax(_i);
  8902 
  8903 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8904 be used in conjunction with the Isabelle symbol font; uses the
  8905 "symbols" syntax table;
  8906 
  8907 * added token_translation interface (may translate name tokens in
  8908 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8909 the current print_mode); IMPORTANT: user print translation functions
  8910 are responsible for marking newly introduced bounds
  8911 (Syntax.mark_boundT);
  8912 
  8913 * token translations for modes "xterm" and "xterm_color" that display
  8914 names in bold, underline etc. or colors (which requires a color
  8915 version of xterm);
  8916 
  8917 * infixes may now be declared with names independent of their syntax;
  8918 
  8919 * added typed_print_translation (like print_translation, but may
  8920 access type of constant);
  8921 
  8922 
  8923 *** Classical Reasoner ***
  8924 
  8925 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8926 some limitations.  Blast_tac...
  8927   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8928   + ignores elimination rules that don't have the correct format
  8929         (the conclusion MUST be a formula variable)
  8930   + ignores types, which can make HOL proofs fail
  8931   + rules must not require higher-order unification, e.g. apply_type in ZF
  8932     [message "Function Var's argument not a bound variable" relates to this]
  8933   + its proof strategy is more general but can actually be slower
  8934 
  8935 * substitution with equality assumptions no longer permutes other
  8936 assumptions;
  8937 
  8938 * minor changes in semantics of addafter (now called addaltern); renamed
  8939 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8940 (and access functions for it);
  8941 
  8942 * improved combination of classical reasoner and simplifier:
  8943   + functions for handling clasimpsets
  8944   + improvement of addss: now the simplifier is called _after_ the
  8945     safe steps.
  8946   + safe variant of addss called addSss: uses safe simplifications
  8947     _during_ the safe steps. It is more complete as it allows multiple
  8948     instantiations of unknowns (e.g. with slow_tac).
  8949 
  8950 *** Simplifier ***
  8951 
  8952 * added interface for simplification procedures (functions that
  8953 produce *proven* rewrite rules on the fly, depending on current
  8954 redex);
  8955 
  8956 * ordering on terms as parameter (used for ordered rewriting);
  8957 
  8958 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8959 
  8960 * the solver is now split into a safe and an unsafe part.
  8961 This should be invisible for the normal user, except that the
  8962 functions setsolver and addsolver have been renamed to setSolver and
  8963 addSolver; added safe_asm_full_simp_tac;
  8964 
  8965 
  8966 *** HOL ***
  8967 
  8968 * a generic induction tactic `induct_tac' which works for all datatypes and
  8969 also for type `nat';
  8970 
  8971 * a generic case distinction tactic `exhaust_tac' which works for all
  8972 datatypes and also for type `nat';
  8973 
  8974 * each datatype comes with a function `size';
  8975 
  8976 * patterns in case expressions allow tuple patterns as arguments to
  8977 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8978 
  8979 * primrec now also works with type nat;
  8980 
  8981 * recdef: a new declaration form, allows general recursive functions to be
  8982 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8983 
  8984 * the constant for negation has been renamed from "not" to "Not" to
  8985 harmonize with FOL, ZF, LK, etc.;
  8986 
  8987 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8988 infinite lists;
  8989 
  8990 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8991 
  8992 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8993 problems in commutative rings, using axiomatic type classes for + and *;
  8994 
  8995 * more examples in HOL/MiniML and HOL/Auth;
  8996 
  8997 * more default rewrite rules for quantifiers, union/intersection;
  8998 
  8999 * a new constant `arbitrary == @x.False';
  9000 
  9001 * HOLCF/IOA replaces old HOL/IOA;
  9002 
  9003 * HOLCF changes: derived all rules and arities
  9004   + axiomatic type classes instead of classes
  9005   + typedef instead of faking type definitions
  9006   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  9007   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  9008   + eliminated the types void, one, tr
  9009   + use unit lift and bool lift (with translations) instead of one and tr
  9010   + eliminated blift from Lift3.thy (use Def instead of blift)
  9011   all eliminated rules are derived as theorems --> no visible changes ;
  9012 
  9013 
  9014 *** ZF ***
  9015 
  9016 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  9017 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  9018 as ZF_cs addSIs [equalityI];
  9019 
  9020 
  9021 
  9022 New in Isabelle94-7 (November 96)
  9023 ---------------------------------
  9024 
  9025 * allowing negative levels (as offsets) in prlev and choplev;
  9026 
  9027 * super-linear speedup for large simplifications;
  9028 
  9029 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  9030 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  9031 FAIL); can suppress it using the command Delsimps (ex_simps @
  9032 all_simps); De Morgan laws are also now included, by default;
  9033 
  9034 * improved printing of ==>  :  ~:
  9035 
  9036 * new object-logic "Sequents" adds linear logic, while replacing LK
  9037 and Modal (thanks to Sara Kalvala);
  9038 
  9039 * HOL/Auth: correctness proofs for authentication protocols;
  9040 
  9041 * HOL: new auto_tac combines rewriting and classical reasoning (many
  9042 examples on HOL/Auth);
  9043 
  9044 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  9045 the rewriter and classical reasoner simultaneously;
  9046 
  9047 * function uresult no longer returns theorems in "standard" format;
  9048 regain previous version by: val uresult = standard o uresult;
  9049 
  9050 
  9051 
  9052 New in Isabelle94-6
  9053 -------------------
  9054 
  9055 * oracles -- these establish an interface between Isabelle and trusted
  9056 external reasoners, which may deliver results as theorems;
  9057 
  9058 * proof objects (in particular record all uses of oracles);
  9059 
  9060 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  9061 
  9062 * "constdefs" section in theory files;
  9063 
  9064 * "primrec" section (HOL) no longer requires names;
  9065 
  9066 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  9067 
  9068 
  9069 
  9070 New in Isabelle94-5
  9071 -------------------
  9072 
  9073 * reduced space requirements;
  9074 
  9075 * automatic HTML generation from theories;
  9076 
  9077 * theory files no longer require "..." (quotes) around most types;
  9078 
  9079 * new examples, including two proofs of the Church-Rosser theorem;
  9080 
  9081 * non-curried (1994) version of HOL is no longer distributed;
  9082 
  9083 
  9084 
  9085 New in Isabelle94-4
  9086 -------------------
  9087 
  9088 * greatly reduced space requirements;
  9089 
  9090 * theory files (.thy) no longer require \...\ escapes at line breaks;
  9091 
  9092 * searchable theorem database (see the section "Retrieving theorems" on
  9093 page 8 of the Reference Manual);
  9094 
  9095 * new examples, including Grabczewski's monumental case study of the
  9096 Axiom of Choice;
  9097 
  9098 * The previous version of HOL renamed to Old_HOL;
  9099 
  9100 * The new version of HOL (previously called CHOL) uses a curried syntax
  9101 for functions.  Application looks like f a b instead of f(a,b);
  9102 
  9103 * Mutually recursive inductive definitions finally work in HOL;
  9104 
  9105 * In ZF, pattern-matching on tuples is now available in all abstractions and
  9106 translates to the operator "split";
  9107 
  9108 
  9109 
  9110 New in Isabelle94-3
  9111 -------------------
  9112 
  9113 * new infix operator, addss, allowing the classical reasoner to
  9114 perform simplification at each step of its search.  Example:
  9115         fast_tac (cs addss ss)
  9116 
  9117 * a new logic, CHOL, the same as HOL, but with a curried syntax
  9118 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  9119 look like (a,b) instead of <a,b>;
  9120 
  9121 * PLEASE NOTE: CHOL will eventually replace HOL!
  9122 
  9123 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  9124 It translates to the operator "split".  A new theory of integers is available;
  9125 
  9126 * In ZF, integer numerals now denote two's-complement binary integers.
  9127 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  9128 
  9129 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  9130 of the Axiom of Choice;
  9131 
  9132 
  9133 
  9134 New in Isabelle94-2
  9135 -------------------
  9136 
  9137 * Significantly faster resolution;
  9138 
  9139 * the different sections in a .thy file can now be mixed and repeated
  9140 freely;
  9141 
  9142 * Database of theorems for FOL, HOL and ZF.  New
  9143 commands including qed, qed_goal and bind_thm store theorems in the database.
  9144 
  9145 * Simple database queries: return a named theorem (get_thm) or all theorems of
  9146 a given theory (thms_of), or find out what theory a theorem was proved in
  9147 (theory_of_thm);
  9148 
  9149 * Bugs fixed in the inductive definition and datatype packages;
  9150 
  9151 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  9152 and HOL_dup_cs obsolete;
  9153 
  9154 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  9155 have been removed;
  9156 
  9157 * Simpler definition of function space in ZF;
  9158 
  9159 * new results about cardinal and ordinal arithmetic in ZF;
  9160 
  9161 * 'subtype' facility in HOL for introducing new types as subsets of existing
  9162 types;
  9163 
  9164 :mode=text:wrap=hard:maxLineLen=72: