NEWS
author huffman
Tue, 27 Mar 2012 15:27:49 +0200
changeset 48030 978c00c20a59
parent 48013 d64fa2ca54b8
child 48031 8ada79014cb2
permissions -rw-r--r--
generalize some theorems about div/mod
     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 
    15 * Updated and extended reference manuals ("isar-ref" and
    16 "implementation"); reduced remaining material in old "ref" manual.
    17 
    18 * Rule attributes in local theory declarations (e.g. locale or class)
    19 are now statically evaluated: the resulting theorem is stored instead
    20 of the original expression.  INCOMPATIBILITY in rare situations, where
    21 the historic accident of dynamic re-evaluation in interpretations
    22 etc. was exploited.
    23 
    24 * Commands 'lemmas' and 'theorems' allow local variables using 'for'
    25 declaration, and results are standardized before being stored.  Thus
    26 old-style "standard" after instantiation or composition of facts
    27 becomes obsolete.  Minor INCOMPATIBILITY, due to potential change of
    28 indices of schematic variables.
    29 
    30 * Renamed some inner syntax categories:
    31 
    32     num ~> num_token
    33     xnum ~> xnum_token
    34     xstr ~> str_token
    35 
    36 Minor INCOMPATIBILITY.  Note that in practice "num_const" or
    37 "num_position" etc. are mainly used instead (which also include
    38 position information via constraints).
    39 
    40 * Simplified configuration options for syntax ambiguity: see
    41 "syntax_ambiguity_warning" and "syntax_ambiguity_limit" in isar-ref
    42 manual.  Minor INCOMPATIBILITY.
    43 
    44 * Forward declaration of outer syntax keywords within the theory
    45 header -- minor INCOMPATIBILITY for user-defined commands.  Allow new
    46 commands to be used in the same theory where defined.
    47 
    48 * ISABELLE_JDK_HOME settings variable points to JDK with javac and jar
    49 (not just JRE), derived from JAVA_HOME from the shell environment or
    50 java.home of the running JVM.
    51 
    52 
    53 *** Pure ***
    54 
    55 * Command 'definition' no longer exports the foundational "raw_def"
    56 into the user context.  Minor INCOMPATIBILITY, may use the regular
    57 "def" result with attribute "abs_def" to imitate the old version.
    58 
    59 * Attribute "abs_def" turns an equation of the form "f x y == t" into
    60 "f == %x y. t", which ensures that "simp" or "unfold" steps always
    61 expand it.  This also works for object-logic equality.  (Formerly
    62 undocumented feature.)
    63 
    64 * Discontinued old "prems" fact, which used to refer to the accidental
    65 collection of foundational premises in the context (marked as legacy
    66 since Isabelle2011).
    67 
    68 * Obsolete command 'types' has been discontinued.  Use 'type_synonym'
    69 instead.  INCOMPATIBILITY.
    70 
    71 * Ancient code generator for SML and its commands 'code_module',
    72 'code_library', 'consts_code', 'types_code' have been discontinued.
    73 Use commands of the generic code generator instead.  INCOMPATIBILITY.
    74 
    75 * Redundant attribute 'code_inline' has been discontinued. Use
    76 'code_unfold' instead.  INCOMPATIBILITY.
    77 
    78 * Dropped attribute 'code_unfold_post' in favor of the its dual
    79 'code_abbrev', which yields a common pattern in definitions like
    80 
    81   definition [code_abbrev]: "f = t"
    82 
    83 INCOMPATIBILITY.
    84 
    85 * Sort constraints are now propagated in simultaneous statements, just
    86 like type constraints.  INCOMPATIBILITY in rare situations, where
    87 distinct sorts used to be assigned accidentally.  For example:
    88 
    89   lemma "P (x::'a::foo)" and "Q (y::'a::bar)"  -- "now illegal"
    90 
    91   lemma "P (x::'a)" and "Q (y::'a::bar)"
    92     -- "now uniform 'a::bar instead of default sort for first occurence (!)"
    93 
    94 
    95 *** HOL ***
    96 
    97 * The representation of numerals has changed. We now have a datatype
    98 "num" representing strictly positive binary numerals, along with
    99 functions "numeral :: num => 'a" and "neg_numeral :: num => 'a" to
   100 represent positive and negated numeric literals, respectively. (See
   101 definitions in Num.thy.) Potential INCOMPATIBILITY; some user theories
   102 may require adaptations:
   103 
   104   - Theorems with number_ring or number_semiring constraints: These
   105     classes are gone; use comm_ring_1 or comm_semiring_1 instead.
   106 
   107   - Theories defining numeric types: Remove number, number_semiring,
   108     and number_ring instances. Defer all theorems about numerals until
   109     after classes one and semigroup_add have been instantiated.
   110 
   111   - Numeral-only simp rules: Replace each rule having a "number_of v"
   112     pattern with two copies, one for numeral and one for neg_numeral.
   113 
   114   - Theorems about subclasses of semiring_1 or ring_1: These classes
   115     automatically support numerals now, so more simp rules and
   116     simprocs may now apply within the proof.
   117 
   118   - Definitions and theorems using old constructors Pls/Min/Bit0/Bit1:
   119     Redefine using other integer operations.
   120 
   121 * Type 'a set is now a proper type constructor (just as before
   122 Isabelle2008).  Definitions mem_def and Collect_def have disappeared.
   123 Non-trivial INCOMPATIBILITY.  For developments keeping predicates and
   124 sets separate, it is often sufficient to rephrase sets S accidentally
   125 used as predicates by "%x. x : S" and predicates P accidentally used
   126 as sets by "{x. P x}".  Corresponding proofs in a first step should be
   127 pruned from any tinkering with former theorems mem_def and
   128 Collect_def as far as possible.
   129 For developments which deliberately mixed predicates and
   130 sets, a planning step is necessary to determine what should become a
   131 predicate and what a set.  It can be helpful to carry out that step in
   132 Isabelle2011-1 before jumping right into the current release.
   133 
   134 * Code generation by default implements sets as container type rather
   135 than predicates.  INCOMPATIBILITY.
   136 
   137 * New type synonym 'a rel = ('a * 'a) set
   138 
   139 * Theory Divides: Discontinued redundant theorems about div and mod.
   140 INCOMPATIBILITY, use the corresponding generic theorems instead.
   141 
   142   DIVISION_BY_ZERO ~> div_by_0, mod_by_0
   143   zdiv_self ~> div_self
   144   zmod_self ~> mod_self
   145   zdiv_zero ~> div_0
   146   zmod_zero ~> mod_0
   147   zmod_zdiv_trivial ~> mod_div_trivial
   148   zdiv_zminus_zminus ~> div_minus_minus
   149   zmod_zminus_zminus ~> mod_minus_minus
   150   zdiv_zminus2 ~> div_minus_right
   151   zmod_zminus2 ~> mod_minus_right
   152   mod_mult_distrib ~> mult_mod_left
   153   mod_mult_distrib2 ~> mult_mod_right
   154 
   155 * More default pred/set conversions on a couple of relation operations
   156 and predicates.  Consolidation of some relation theorems:
   157 
   158   converse_def ~> converse_unfold
   159   rel_comp_def ~> rel_comp_unfold
   160   symp_def ~> (dropped, use symp_def and sym_def instead)
   161   transp_def ~> transp_trans
   162   Domain_def ~> Domain_unfold
   163   Range_def ~> Domain_converse [symmetric]
   164 
   165 Generalized theorems INF_INT_eq, INF_INT_eq2, SUP_UN_eq, SUP_UN_eq2.
   166 
   167 See theory "Relation" for examples for making use of pred/set conversions
   168 by means of attributes "to_set" and "to_pred".
   169 
   170 INCOMPATIBILITY.
   171 
   172 * Consolidated various theorem names relating to Finite_Set.fold
   173 combinator:
   174 
   175   inf_INFI_fold_inf ~> inf_INF_fold_inf
   176   sup_SUPR_fold_sup ~> sup_SUP_fold_sup
   177   INFI_fold_inf ~> INF_fold_inf
   178   SUPR_fold_sup ~> SUP_fold_sup
   179   union_set ~> union_set_fold
   180   minus_set ~> minus_set_fold
   181 
   182 INCOMPATIBILITY.
   183 
   184 * Consolidated theorem names concerning fold combinators:
   185 
   186   INFI_set_fold ~> INF_set_fold
   187   SUPR_set_fold ~> SUP_set_fold
   188   INF_code ~> INF_set_foldr
   189   SUP_code ~> SUP_set_foldr
   190   foldr.simps ~> foldr_Nil foldr_Cons (in point-free formulation)
   191   foldl.simps ~> foldl_Nil foldl_Cons
   192   foldr_fold_rev ~> foldr_def
   193   foldl_fold ~> foldl_def
   194 
   195 INCOMPATIBILITY.
   196 
   197 * Dropped rarely useful theorems concerning fold combinators:
   198 foldl_apply, foldl_fun_comm, foldl_rev, fold_weak_invariant,
   199 rev_foldl_cons, fold_set_remdups, fold_set, fold_set1,
   200 concat_conv_foldl, foldl_weak_invariant, foldl_invariant,
   201 foldr_invariant, foldl_absorb0, foldl_foldr1_lemma, foldl_foldr1,
   202 listsum_conv_fold, listsum_foldl, sort_foldl_insort.  INCOMPATIBILITY.
   203 Prefer "List.fold" with canonical argument order, or boil down
   204 "List.foldr" and "List.foldl" to "List.fold" by unfolding "foldr_def"
   205 and "foldl_def".  For the common phrases "%xs. List.foldr plus xs 0"
   206 and "List.foldl plus 0", prefer "List.listsum".
   207 
   208 * Congruence rules Option.map_cong and Option.bind_cong for recursion
   209 through option types.
   210 
   211 * Concrete syntax for case expressions includes constraints for source
   212 positions, and thus produces Prover IDE markup for its bindings.
   213 INCOMPATIBILITY for old-style syntax translations that augment the
   214 pattern notation; e.g. see src/HOL/HOLCF/One.thy for translations of
   215 one_case.
   216 
   217 * Discontinued configuration option "syntax_positions": atomic terms
   218 in parse trees are always annotated by position constraints.
   219 
   220 * Finite_Set.fold now qualified.  INCOMPATIBILITY.
   221 
   222 * Renamed some facts on canonical fold on lists, in order to avoid
   223 problems with interpretation involving corresponding facts on foldl
   224 with the same base names:
   225 
   226   fold_set_remdups ~> fold_set_fold_remdups
   227   fold_set ~> fold_set_fold
   228   fold1_set ~> fold1_set_fold
   229 
   230 INCOMPATIBILITY.
   231 
   232 * Renamed facts about the power operation on relations, i.e., relpow
   233   to match the constant's name:
   234   
   235   rel_pow_1 ~> relpow_1
   236   rel_pow_0_I ~> relpow_0_I
   237   rel_pow_Suc_I ~> relpow_Suc_I
   238   rel_pow_Suc_I2 ~> relpow_Suc_I2
   239   rel_pow_0_E ~> relpow_0_E
   240   rel_pow_Suc_E ~> relpow_Suc_E
   241   rel_pow_E ~> relpow_E
   242   rel_pow_Suc_D2 ~> relpow_Suc_D2
   243   rel_pow_Suc_E2 ~> relpow_Suc_E2 
   244   rel_pow_Suc_D2' ~> relpow_Suc_D2'
   245   rel_pow_E2 ~> relpow_E2
   246   rel_pow_add ~> relpow_add
   247   rel_pow_commute ~> relpow
   248   rel_pow_empty ~> relpow_empty:
   249   rtrancl_imp_UN_rel_pow ~> rtrancl_imp_UN_relpow
   250   rel_pow_imp_rtrancl ~> relpow_imp_rtrancl
   251   rtrancl_is_UN_rel_pow ~> rtrancl_is_UN_relpow
   252   rtrancl_imp_rel_pow ~> rtrancl_imp_relpow
   253   rel_pow_fun_conv ~> relpow_fun_conv
   254   rel_pow_finite_bounded1 ~> relpow_finite_bounded1
   255   rel_pow_finite_bounded ~> relpow_finite_bounded
   256   rtrancl_finite_eq_rel_pow ~> rtrancl_finite_eq_relpow
   257   trancl_finite_eq_rel_pow ~> trancl_finite_eq_relpow
   258   single_valued_rel_pow ~> single_valued_relpow
   259  
   260 INCOMPATIBILITY.
   261 
   262 * New theory HOL/Library/DAList provides an abstract type for association
   263   lists with distinct keys.
   264 
   265 * 'datatype' specifications allow explicit sort constraints.
   266 
   267 * Theory HOL/Library/Diagonalize has been removed. INCOMPATIBILITY,
   268 use theory HOL/Library/Nat_Bijection instead.
   269 
   270 * Session HOL-Word: Discontinued many redundant theorems specific to
   271 type 'a word. INCOMPATIBILITY, use the corresponding generic theorems
   272 instead.
   273 
   274   word_sub_alt ~> word_sub_wi
   275   word_add_alt ~> word_add_def
   276   word_mult_alt ~> word_mult_def
   277   word_minus_alt ~> word_minus_def
   278   word_0_alt ~> word_0_wi
   279   word_1_alt ~> word_1_wi
   280   word_add_0 ~> add_0_left
   281   word_add_0_right ~> add_0_right
   282   word_mult_1 ~> mult_1_left
   283   word_mult_1_right ~> mult_1_right
   284   word_add_commute ~> add_commute
   285   word_add_assoc ~> add_assoc
   286   word_add_left_commute ~> add_left_commute
   287   word_mult_commute ~> mult_commute
   288   word_mult_assoc ~> mult_assoc
   289   word_mult_left_commute ~> mult_left_commute
   290   word_left_distrib ~> left_distrib
   291   word_right_distrib ~> right_distrib
   292   word_left_minus ~> left_minus
   293   word_diff_0_right ~> diff_0_right
   294   word_diff_self ~> diff_self
   295   word_sub_def ~> diff_minus
   296   word_diff_minus ~> diff_minus
   297   word_add_ac ~> add_ac
   298   word_mult_ac ~> mult_ac
   299   word_plus_ac0 ~> add_0_left add_0_right add_ac
   300   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
   301   word_order_trans ~> order_trans
   302   word_order_refl ~> order_refl
   303   word_order_antisym ~> order_antisym
   304   word_order_linear ~> linorder_linear
   305   lenw1_zero_neq_one ~> zero_neq_one
   306   word_number_of_eq ~> number_of_eq
   307   word_of_int_add_hom ~> wi_hom_add
   308   word_of_int_sub_hom ~> wi_hom_sub
   309   word_of_int_mult_hom ~> wi_hom_mult
   310   word_of_int_minus_hom ~> wi_hom_neg
   311   word_of_int_succ_hom ~> wi_hom_succ
   312   word_of_int_pred_hom ~> wi_hom_pred
   313   word_of_int_0_hom ~> word_0_wi
   314   word_of_int_1_hom ~> word_1_wi
   315 
   316 * Clarified attribute "mono_set": pure declaration without modifying
   317 the result of the fact expression.
   318 
   319 * "Transitive_Closure.ntrancl": bounded transitive closure on
   320 relations.
   321 
   322 * Constant "Set.not_member" now qualified.  INCOMPATIBILITY.
   323 
   324 * "sublists" moved to theory More_List.  INCOMPATIBILITY.
   325 
   326 * Theory Int: Discontinued many legacy theorems specific to type int.
   327 INCOMPATIBILITY, use the corresponding generic theorems instead.
   328 
   329   zminus_zminus ~> minus_minus
   330   zminus_0 ~> minus_zero
   331   zminus_zadd_distrib ~> minus_add_distrib
   332   zadd_commute ~> add_commute
   333   zadd_assoc ~> add_assoc
   334   zadd_left_commute ~> add_left_commute
   335   zadd_ac ~> add_ac
   336   zmult_ac ~> mult_ac
   337   zadd_0 ~> add_0_left
   338   zadd_0_right ~> add_0_right
   339   zadd_zminus_inverse2 ~> left_minus
   340   zmult_zminus ~> mult_minus_left
   341   zmult_commute ~> mult_commute
   342   zmult_assoc ~> mult_assoc
   343   zadd_zmult_distrib ~> left_distrib
   344   zadd_zmult_distrib2 ~> right_distrib
   345   zdiff_zmult_distrib ~> left_diff_distrib
   346   zdiff_zmult_distrib2 ~> right_diff_distrib
   347   zmult_1 ~> mult_1_left
   348   zmult_1_right ~> mult_1_right
   349   zle_refl ~> order_refl
   350   zle_trans ~> order_trans
   351   zle_antisym ~> order_antisym
   352   zle_linear ~> linorder_linear
   353   zless_linear ~> linorder_less_linear
   354   zadd_left_mono ~> add_left_mono
   355   zadd_strict_right_mono ~> add_strict_right_mono
   356   zadd_zless_mono ~> add_less_le_mono
   357   int_0_less_1 ~> zero_less_one
   358   int_0_neq_1 ~> zero_neq_one
   359   zless_le ~> less_le
   360   zpower_zadd_distrib ~> power_add
   361   zero_less_zpower_abs_iff ~> zero_less_power_abs_iff
   362   zero_le_zpower_abs ~> zero_le_power_abs
   363 
   364 * Theory Deriv: Renamed
   365 
   366   DERIV_nonneg_imp_nonincreasing ~> DERIV_nonneg_imp_nondecreasing
   367 
   368 * New "case_product" attribute to generate a case rule doing multiple
   369 case distinctions at the same time.  E.g.
   370 
   371   list.exhaust [case_product nat.exhaust]
   372 
   373 produces a rule which can be used to perform case distinction on both
   374 a list and a nat.
   375 
   376 * Improved code generation of multisets.
   377 
   378 * New diagnostic command find_unused_assms to find potentially superfluous
   379   assumptions in theorems using Quickcheck.
   380 
   381 * Quickcheck:
   382   - Quickcheck returns variable assignments as counterexamples, which
   383     allows to reveal the underspecification of functions under test.
   384     For example, refuting "hd xs = x", it presents the variable
   385     assignment xs = [] and x = a1 as a counterexample, assuming that
   386     any property is false whenever "hd []" occurs in it.
   387     These counterexample are marked as potentially spurious, as
   388     Quickcheck also returns "xs = []" as a counterexample to the
   389     obvious theorem "hd xs = hd xs".
   390     After finding a potentially spurious counterexample, Quickcheck
   391     continues searching for genuine ones.
   392     By default, Quickcheck shows potentially spurious and genuine
   393     counterexamples. The option "genuine_only" sets quickcheck to
   394     only show genuine counterexamples.
   395 
   396   - The command 'quickcheck_generator' creates random and exhaustive
   397     value generators for a given type and operations.
   398     It generates values by using the operations as if they were
   399     constructors of that type. 
   400 
   401   - Support for multisets.
   402 
   403   - Added "use_subtype" options.
   404  
   405 * Nitpick:
   406   - Fixed infinite loop caused by the 'peephole_optim' option and
   407     affecting 'rat' and 'real'.
   408 
   409 * Sledgehammer:
   410   - Added "lam_trans", "uncurry_aliases", and "minimize" options.
   411   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   412   - Renamed "sound" option to "strict".
   413 
   414 * Metis:
   415   - Added possibility to specify lambda translations scheme as a
   416     parenthesized argument (e.g., "by (metis (lifting) ...)").
   417 
   418 * Command 'try0':
   419   - Renamed from 'try_methods'. INCOMPATIBILITY.
   420 
   421 * New "eventually_elim" method as a generalized variant of the
   422   eventually_elim* rules. Supports structured proofs.
   423 
   424 
   425 *** FOL ***
   426 
   427 * New "case_product" attribute (see HOL).
   428 
   429 
   430 *** ML ***
   431 
   432 * Antiquotation @{keyword "name"} produces a parser for outer syntax
   433 from a minor keyword introduced via theory header declaration.
   434 
   435 * Antiquotation @{command_spec "name"} produces the
   436 Outer_Syntax.command_spec from a major keyword introduced via theory
   437 header declaration; it can be passed to Outer_Syntax.command etc.
   438 
   439 * Local_Theory.define no longer hard-wires default theorem name
   440 "foo_def", but retains the binding as given.  If that is Binding.empty
   441 / Attrib.empty_binding, the result is not registered as user-level
   442 fact.  The Local_Theory.define_internal variant allows to specify a
   443 non-empty name (used for the foundation in the background theory),
   444 while omitting the fact binding in the user-context.  Potential
   445 INCOMPATIBILITY for derived definitional packages: need to specify
   446 naming policy for primitive definitions more explicitly.
   447 
   448 * Renamed Thm.capply to Thm.apply, and Thm.cabs to Thm.lambda in
   449 conformance with similar operations in structure Term and Logic.
   450 
   451 * Antiquotation @{attributes [...]} embeds attribute source
   452 representation into the ML text, which is particularly useful with
   453 declarations like Local_Theory.note.
   454 
   455 * Structure Proof_Context follows standard naming scheme.  Old
   456 ProofContext has been discontinued.  INCOMPATIBILITY.
   457 
   458 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
   459 change of semantics: update is applied to auxiliary local theory
   460 context as well.
   461 
   462 * Modernized some old-style infix operations:
   463 
   464   addeqcongs    ~> Simplifier.add_eqcong
   465   deleqcongs    ~> Simplifier.del_eqcong
   466   addcongs      ~> Simplifier.add_cong
   467   delcongs      ~> Simplifier.del_cong
   468   setmksimps    ~> Simplifier.set_mksimps
   469   setmkcong     ~> Simplifier.set_mkcong
   470   setmksym      ~> Simplifier.set_mksym
   471   setmkeqTrue   ~> Simplifier.set_mkeqTrue
   472   settermless   ~> Simplifier.set_termless
   473   setsubgoaler  ~> Simplifier.set_subgoaler
   474   addsplits     ~> Splitter.add_split
   475   delsplits     ~> Splitter.del_split
   476 
   477 
   478 
   479 New in Isabelle2011-1 (October 2011)
   480 ------------------------------------
   481 
   482 *** General ***
   483 
   484 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
   485 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
   486 
   487   - Management of multiple theory files directly from the editor
   488     buffer store -- bypassing the file-system (no requirement to save
   489     files for checking).
   490 
   491   - Markup of formal entities within the text buffer, with semantic
   492     highlighting, tooltips and hyperlinks to jump to defining source
   493     positions.
   494 
   495   - Improved text rendering, with sub/superscripts in the source
   496     buffer (including support for copy/paste wrt. output panel, HTML
   497     theory output and other non-Isabelle text boxes).
   498 
   499   - Refined scheduling of proof checking and printing of results,
   500     based on interactive editor view.  (Note: jEdit folding and
   501     narrowing allows to restrict buffer perspectives explicitly.)
   502 
   503   - Reduced CPU performance requirements, usable on machines with few
   504     cores.
   505 
   506   - Reduced memory requirements due to pruning of unused document
   507     versions (garbage collection).
   508 
   509 See also ~~/src/Tools/jEdit/README.html for further information,
   510 including some remaining limitations.
   511 
   512 * Theory loader: source files are exclusively located via the master
   513 directory of each theory node (where the .thy file itself resides).
   514 The global load path (such as src/HOL/Library) has been discontinued.
   515 Note that the path element ~~ may be used to reference theories in the
   516 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
   517 INCOMPATIBILITY.
   518 
   519 * Theory loader: source files are identified by content via SHA1
   520 digests.  Discontinued former path/modtime identification and optional
   521 ISABELLE_FILE_IDENT plugin scripts.
   522 
   523 * Parallelization of nested Isar proofs is subject to
   524 Goal.parallel_proofs_threshold (default 100).  See also isabelle
   525 usedir option -Q.
   526 
   527 * Name space: former unsynchronized references are now proper
   528 configuration options, with more conventional names:
   529 
   530   long_names   ~> names_long
   531   short_names  ~> names_short
   532   unique_names ~> names_unique
   533 
   534 Minor INCOMPATIBILITY, need to declare options in context like this:
   535 
   536   declare [[names_unique = false]]
   537 
   538 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
   539 that the result needs to be unique, which means fact specifications
   540 may have to be refined after enriching a proof context.
   541 
   542 * Attribute "case_names" has been refined: the assumptions in each case
   543 can be named now by following the case name with [name1 name2 ...].
   544 
   545 * Isabelle/Isar reference manual has been updated and extended:
   546   - "Synopsis" provides a catalog of main Isar language concepts.
   547   - Formal references in syntax diagrams, via @{rail} antiquotation.
   548   - Updated material from classic "ref" manual, notably about
   549     "Classical Reasoner".
   550 
   551 
   552 *** HOL ***
   553 
   554 * Class bot and top require underlying partial order rather than
   555 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
   556 
   557 * Class complete_lattice: generalized a couple of lemmas from sets;
   558 generalized theorems INF_cong and SUP_cong.  New type classes for
   559 complete boolean algebras and complete linear orders.  Lemmas
   560 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
   561 class complete_linorder.
   562 
   563 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
   564 Sup_fun_def, Inf_apply, Sup_apply.
   565 
   566 Removed redundant lemmas (the right hand side gives hints how to
   567 replace them for (metis ...), or (simp only: ...) proofs):
   568 
   569   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
   570   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
   571   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
   572   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
   573   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
   574   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
   575   Inter_def ~> INF_def, image_def
   576   Union_def ~> SUP_def, image_def
   577   INT_eq ~> INF_def, and image_def
   578   UN_eq ~> SUP_def, and image_def
   579   INF_subset ~> INF_superset_mono [OF _ order_refl]
   580 
   581 More consistent and comprehensive names:
   582 
   583   INTER_eq_Inter_image ~> INF_def
   584   UNION_eq_Union_image ~> SUP_def
   585   INFI_def ~> INF_def
   586   SUPR_def ~> SUP_def
   587   INF_leI ~> INF_lower
   588   INF_leI2 ~> INF_lower2
   589   le_INFI ~> INF_greatest
   590   le_SUPI ~> SUP_upper
   591   le_SUPI2 ~> SUP_upper2
   592   SUP_leI ~> SUP_least
   593   INFI_bool_eq ~> INF_bool_eq
   594   SUPR_bool_eq ~> SUP_bool_eq
   595   INFI_apply ~> INF_apply
   596   SUPR_apply ~> SUP_apply
   597   INTER_def ~> INTER_eq
   598   UNION_def ~> UNION_eq
   599 
   600 INCOMPATIBILITY.
   601 
   602 * Renamed theory Complete_Lattice to Complete_Lattices.
   603 INCOMPATIBILITY.
   604 
   605 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
   606 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
   607 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
   608 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
   609 
   610 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
   611 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
   612 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
   613 INCOMPATIBILITY.
   614 
   615 * Added syntactic classes "inf" and "sup" for the respective
   616 constants.  INCOMPATIBILITY: Changes in the argument order of the
   617 (mostly internal) locale predicates for some derived classes.
   618 
   619 * Theorem collections ball_simps and bex_simps do not contain theorems
   620 referring to UNION any longer; these have been moved to collection
   621 UN_ball_bex_simps.  INCOMPATIBILITY.
   622 
   623 * Theory Archimedean_Field: floor now is defined as parameter of a
   624 separate type class floor_ceiling.
   625 
   626 * Theory Finite_Set: more coherent development of fold_set locales:
   627 
   628     locale fun_left_comm ~> locale comp_fun_commute
   629     locale fun_left_comm_idem ~> locale comp_fun_idem
   630 
   631 Both use point-free characterization; interpretation proofs may need
   632 adjustment.  INCOMPATIBILITY.
   633 
   634 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
   635 accordance with standard mathematical terminology. INCOMPATIBILITY.
   636 
   637 * Theory Complex_Main: The locale interpretations for the
   638 bounded_linear and bounded_bilinear locales have been removed, in
   639 order to reduce the number of duplicate lemmas. Users must use the
   640 original names for distributivity theorems, potential INCOMPATIBILITY.
   641 
   642   divide.add ~> add_divide_distrib
   643   divide.diff ~> diff_divide_distrib
   644   divide.setsum ~> setsum_divide_distrib
   645   mult.add_right ~> right_distrib
   646   mult.diff_right ~> right_diff_distrib
   647   mult_right.setsum ~> setsum_right_distrib
   648   mult_left.diff ~> left_diff_distrib
   649 
   650 * Theory Complex_Main: Several redundant theorems have been removed or
   651 replaced by more general versions. INCOMPATIBILITY.
   652 
   653   real_diff_def ~> minus_real_def
   654   real_divide_def ~> divide_real_def
   655   real_less_def ~> less_le
   656   real_abs_def ~> abs_real_def
   657   real_sgn_def ~> sgn_real_def
   658   real_mult_commute ~> mult_commute
   659   real_mult_assoc ~> mult_assoc
   660   real_mult_1 ~> mult_1_left
   661   real_add_mult_distrib ~> left_distrib
   662   real_zero_not_eq_one ~> zero_neq_one
   663   real_mult_inverse_left ~> left_inverse
   664   INVERSE_ZERO ~> inverse_zero
   665   real_le_refl ~> order_refl
   666   real_le_antisym ~> order_antisym
   667   real_le_trans ~> order_trans
   668   real_le_linear ~> linear
   669   real_le_eq_diff ~> le_iff_diff_le_0
   670   real_add_left_mono ~> add_left_mono
   671   real_mult_order ~> mult_pos_pos
   672   real_mult_less_mono2 ~> mult_strict_left_mono
   673   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
   674   real_0_le_divide_iff ~> zero_le_divide_iff
   675   realpow_two_disj ~> power2_eq_iff
   676   real_squared_diff_one_factored ~> square_diff_one_factored
   677   realpow_two_diff ~> square_diff_square_factored
   678   reals_complete2 ~> complete_real
   679   real_sum_squared_expand ~> power2_sum
   680   exp_ln_eq ~> ln_unique
   681   expi_add ~> exp_add
   682   expi_zero ~> exp_zero
   683   lemma_DERIV_subst ~> DERIV_cong
   684   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
   685   LIMSEQ_const ~> tendsto_const
   686   LIMSEQ_norm ~> tendsto_norm
   687   LIMSEQ_add ~> tendsto_add
   688   LIMSEQ_minus ~> tendsto_minus
   689   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
   690   LIMSEQ_diff ~> tendsto_diff
   691   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
   692   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
   693   LIMSEQ_mult ~> tendsto_mult
   694   LIMSEQ_inverse ~> tendsto_inverse
   695   LIMSEQ_divide ~> tendsto_divide
   696   LIMSEQ_pow ~> tendsto_power
   697   LIMSEQ_setsum ~> tendsto_setsum
   698   LIMSEQ_setprod ~> tendsto_setprod
   699   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
   700   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
   701   LIMSEQ_imp_rabs ~> tendsto_rabs
   702   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
   703   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
   704   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
   705   LIMSEQ_Complex ~> tendsto_Complex
   706   LIM_ident ~> tendsto_ident_at
   707   LIM_const ~> tendsto_const
   708   LIM_add ~> tendsto_add
   709   LIM_add_zero ~> tendsto_add_zero
   710   LIM_minus ~> tendsto_minus
   711   LIM_diff ~> tendsto_diff
   712   LIM_norm ~> tendsto_norm
   713   LIM_norm_zero ~> tendsto_norm_zero
   714   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
   715   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
   716   LIM_rabs ~> tendsto_rabs
   717   LIM_rabs_zero ~> tendsto_rabs_zero
   718   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
   719   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
   720   LIM_compose ~> tendsto_compose
   721   LIM_mult ~> tendsto_mult
   722   LIM_scaleR ~> tendsto_scaleR
   723   LIM_of_real ~> tendsto_of_real
   724   LIM_power ~> tendsto_power
   725   LIM_inverse ~> tendsto_inverse
   726   LIM_sgn ~> tendsto_sgn
   727   isCont_LIM_compose ~> isCont_tendsto_compose
   728   bounded_linear.LIM ~> bounded_linear.tendsto
   729   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
   730   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
   731   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
   732   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
   733   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
   734   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
   735 
   736 * Theory Complex_Main: The definition of infinite series was
   737 generalized.  Now it is defined on the type class {topological_space,
   738 comm_monoid_add}.  Hence it is useable also for extended real numbers.
   739 
   740 * Theory Complex_Main: The complex exponential function "expi" is now
   741 a type-constrained abbreviation for "exp :: complex => complex"; thus
   742 several polymorphic lemmas about "exp" are now applicable to "expi".
   743 
   744 * Code generation:
   745 
   746   - Theory Library/Code_Char_ord provides native ordering of
   747     characters in the target language.
   748 
   749   - Commands code_module and code_library are legacy, use export_code
   750     instead.
   751 
   752   - Method "evaluation" is legacy, use method "eval" instead.
   753 
   754   - Legacy evaluator "SML" is deactivated by default.  May be
   755     reactivated by the following theory command:
   756 
   757       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   758 
   759 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   760 
   761 * New proof method "induction" that gives induction hypotheses the
   762 name "IH", thus distinguishing them from further hypotheses that come
   763 from rule induction.  The latter are still called "hyps".  Method
   764 "induction" is a thin wrapper around "induct" and follows the same
   765 syntax.
   766 
   767 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
   768 still available as a legacy feature for some time.
   769 
   770 * Nitpick:
   771   - Added "need" and "total_consts" options.
   772   - Reintroduced "show_skolems" option by popular demand.
   773   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   774     INCOMPATIBILITY.
   775 
   776 * Sledgehammer:
   777   - Use quasi-sound (and efficient) translations by default.
   778   - Added support for the following provers: E-ToFoF, LEO-II,
   779     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
   780   - Automatically preplay and minimize proofs before showing them if
   781     this can be done within reasonable time.
   782   - sledgehammer available_provers ~> sledgehammer supported_provers.
   783     INCOMPATIBILITY.
   784   - Added "preplay_timeout", "slicing", "type_enc", "sound",
   785     "max_mono_iters", and "max_new_mono_instances" options.
   786   - Removed "explicit_apply" and "full_types" options as well as "Full
   787     Types" Proof General menu item. INCOMPATIBILITY.
   788 
   789 * Metis:
   790   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   791   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
   792     INCOMPATIBILITY.
   793 
   794 * Command 'try':
   795   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
   796     "elim:" options. INCOMPATIBILITY.
   797   - Introduced 'try' that not only runs 'try_methods' but also
   798     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
   799 
   800 * Quickcheck:
   801   - Added "eval" option to evaluate terms for the found counterexample
   802     (currently only supported by the default (exhaustive) tester).
   803   - Added post-processing of terms to obtain readable counterexamples
   804     (currently only supported by the default (exhaustive) tester).
   805   - New counterexample generator quickcheck[narrowing] enables
   806     narrowing-based testing.  Requires the Glasgow Haskell compiler
   807     with its installation location defined in the Isabelle settings
   808     environment as ISABELLE_GHC.
   809   - Removed quickcheck tester "SML" based on the SML code generator
   810     (formly in HOL/Library).
   811 
   812 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
   813 use 'partial_function' instead.
   814 
   815 * Theory Library/Extended_Reals replaces now the positive extended
   816 reals found in probability theory. This file is extended by
   817 Multivariate_Analysis/Extended_Real_Limits.
   818 
   819 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
   820 from where it must be imported explicitly if it is really required.
   821 INCOMPATIBILITY.
   822 
   823 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
   824 been moved here.  INCOMPATIBILITY.
   825 
   826 * Theory Library/Saturated provides type of numbers with saturated
   827 arithmetic.
   828 
   829 * Theory Library/Product_Lattice defines a pointwise ordering for the
   830 product type 'a * 'b, and provides instance proofs for various order
   831 and lattice type classes.
   832 
   833 * Theory Library/Countable now provides the "countable_datatype" proof
   834 method for proving "countable" class instances for datatypes.
   835 
   836 * Theory Library/Cset_Monad allows do notation for computable sets
   837 (cset) via the generic monad ad-hoc overloading facility.
   838 
   839 * Library: Theories of common data structures are split into theories
   840 for implementation, an invariant-ensuring type, and connection to an
   841 abstract type. INCOMPATIBILITY.
   842 
   843   - RBT is split into RBT and RBT_Mapping.
   844   - AssocList is split and renamed into AList and AList_Mapping.
   845   - DList is split into DList_Impl, DList, and DList_Cset.
   846   - Cset is split into Cset and List_Cset.
   847 
   848 * Theory Library/Nat_Infinity has been renamed to
   849 Library/Extended_Nat, with name changes of the following types and
   850 constants:
   851 
   852   type inat   ~> type enat
   853   Fin         ~> enat
   854   Infty       ~> infinity (overloaded)
   855   iSuc        ~> eSuc
   856   the_Fin     ~> the_enat
   857 
   858 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   859 been renamed accordingly. INCOMPATIBILITY.
   860 
   861 * Session Multivariate_Analysis: The euclidean_space type class now
   862 fixes a constant "Basis :: 'a set" consisting of the standard
   863 orthonormal basis for the type. Users now have the option of
   864 quantifying over this set instead of using the "basis" function, e.g.
   865 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
   866 
   867 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   868 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   869 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   870 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   871 changed to match. Definition theorems for overloaded constants now use
   872 the standard "foo_vec_def" naming scheme. A few other theorems have
   873 been renamed as follows (INCOMPATIBILITY):
   874 
   875   Cart_eq          ~> vec_eq_iff
   876   dist_nth_le_cart ~> dist_vec_nth_le
   877   tendsto_vector   ~> vec_tendstoI
   878   Cauchy_vector    ~> vec_CauchyI
   879 
   880 * Session Multivariate_Analysis: Several duplicate theorems have been
   881 removed, and other theorems have been renamed or replaced with more
   882 general versions. INCOMPATIBILITY.
   883 
   884   finite_choice ~> finite_set_choice
   885   eventually_conjI ~> eventually_conj
   886   eventually_and ~> eventually_conj_iff
   887   eventually_false ~> eventually_False
   888   setsum_norm ~> norm_setsum
   889   Lim_sequentially ~> LIMSEQ_def
   890   Lim_ident_at ~> LIM_ident
   891   Lim_const ~> tendsto_const
   892   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
   893   Lim_neg ~> tendsto_minus
   894   Lim_add ~> tendsto_add
   895   Lim_sub ~> tendsto_diff
   896   Lim_mul ~> tendsto_scaleR
   897   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
   898   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
   899   Lim_linear ~> bounded_linear.tendsto
   900   Lim_component ~> tendsto_euclidean_component
   901   Lim_component_cart ~> tendsto_vec_nth
   902   Lim_inner ~> tendsto_inner [OF tendsto_const]
   903   dot_lsum ~> inner_setsum_left
   904   dot_rsum ~> inner_setsum_right
   905   continuous_cmul ~> continuous_scaleR [OF continuous_const]
   906   continuous_neg ~> continuous_minus
   907   continuous_sub ~> continuous_diff
   908   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
   909   continuous_mul ~> continuous_scaleR
   910   continuous_inv ~> continuous_inverse
   911   continuous_at_within_inv ~> continuous_at_within_inverse
   912   continuous_at_inv ~> continuous_at_inverse
   913   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
   914   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
   915   continuous_at_component ~> continuous_component [OF continuous_at_id]
   916   continuous_on_neg ~> continuous_on_minus
   917   continuous_on_sub ~> continuous_on_diff
   918   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
   919   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
   920   continuous_on_mul ~> continuous_on_scaleR
   921   continuous_on_mul_real ~> continuous_on_mult
   922   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
   923   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
   924   continuous_on_inverse ~> continuous_on_inv
   925   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
   926   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
   927   subset_interior ~> interior_mono
   928   subset_closure ~> closure_mono
   929   closure_univ ~> closure_UNIV
   930   real_arch_lt ~> reals_Archimedean2
   931   real_arch ~> reals_Archimedean3
   932   real_abs_norm ~> abs_norm_cancel
   933   real_abs_sub_norm ~> norm_triangle_ineq3
   934   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
   935 
   936 * Session HOL-Probability:
   937   - Caratheodory's extension lemma is now proved for ring_of_sets.
   938   - Infinite products of probability measures are now available.
   939   - Sigma closure is independent, if the generator is independent
   940   - Use extended reals instead of positive extended
   941     reals. INCOMPATIBILITY.
   942 
   943 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
   944 
   945   expand_fun_below ~> fun_below_iff
   946   below_fun_ext ~> fun_belowI
   947   expand_cfun_eq ~> cfun_eq_iff
   948   ext_cfun ~> cfun_eqI
   949   expand_cfun_below ~> cfun_below_iff
   950   below_cfun_ext ~> cfun_belowI
   951   monofun_fun_fun ~> fun_belowD
   952   monofun_fun_arg ~> monofunE
   953   monofun_lub_fun ~> adm_monofun [THEN admD]
   954   cont_lub_fun ~> adm_cont [THEN admD]
   955   cont2cont_Rep_CFun ~> cont2cont_APP
   956   cont_Rep_CFun_app ~> cont_APP_app
   957   cont_Rep_CFun_app_app ~> cont_APP_app_app
   958   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
   959   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
   960   contlub_cfun ~> lub_APP [symmetric]
   961   contlub_LAM ~> lub_LAM [symmetric]
   962   thelubI ~> lub_eqI
   963   UU_I ~> bottomI
   964   lift_distinct1 ~> lift.distinct(1)
   965   lift_distinct2 ~> lift.distinct(2)
   966   Def_not_UU ~> lift.distinct(2)
   967   Def_inject ~> lift.inject
   968   below_UU_iff ~> below_bottom_iff
   969   eq_UU_iff ~> eq_bottom_iff
   970 
   971 
   972 *** Document preparation ***
   973 
   974 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   975 isar-ref manual, both for description and actual application of the
   976 same.
   977 
   978 * Antiquotation @{value} evaluates the given term and presents its
   979 result.
   980 
   981 * Antiquotations: term style "isub" provides ad-hoc conversion of
   982 variables x1, y23 into subscripted form x\<^isub>1,
   983 y\<^isub>2\<^isub>3.
   984 
   985 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   986 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   987 
   988 * Localized \isabellestyle switch can be used within blocks or groups
   989 like this:
   990 
   991   \isabellestyle{it}  %preferred default
   992   {\isabellestylett @{text "typewriter stuff"}}
   993 
   994 * Discontinued special treatment of hard tabulators.  Implicit
   995 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
   996 layouts.
   997 
   998 
   999 *** ML ***
  1000 
  1001 * The inner syntax of sort/type/term/prop supports inlined YXML
  1002 representations within quoted string tokens.  By encoding logical
  1003 entities via Term_XML (in ML or Scala) concrete syntax can be
  1004 bypassed, which is particularly useful for producing bits of text
  1005 under external program control.
  1006 
  1007 * Antiquotations for ML and document preparation are managed as theory
  1008 data, which requires explicit setup.
  1009 
  1010 * Isabelle_Process.is_active allows tools to check if the official
  1011 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
  1012 (better known as Proof General).
  1013 
  1014 * Structure Proof_Context follows standard naming scheme.  Old
  1015 ProofContext is still available for some time as legacy alias.
  1016 
  1017 * Structure Timing provides various operations for timing; supersedes
  1018 former start_timing/end_timing etc.
  1019 
  1020 * Path.print is the official way to show file-system paths to users
  1021 (including quotes etc.).
  1022 
  1023 * Inner syntax: identifiers in parse trees of generic categories
  1024 "logic", "aprop", "idt" etc. carry position information (disguised as
  1025 type constraints).  Occasional INCOMPATIBILITY with non-compliant
  1026 translations that choke on unexpected type constraints.  Positions can
  1027 be stripped in ML translations via Syntax.strip_positions /
  1028 Syntax.strip_positions_ast, or via the syntax constant
  1029 "_strip_positions" within parse trees.  As last resort, positions can
  1030 be disabled via the configuration option Syntax.positions, which is
  1031 called "syntax_positions" in Isar attribute syntax.
  1032 
  1033 * Discontinued special status of various ML structures that contribute
  1034 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
  1035 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
  1036 refer directly to Ast.Constant, Lexicon.is_identifier,
  1037 Syntax_Trans.mk_binder_tr etc.
  1038 
  1039 * Typed print translation: discontinued show_sorts argument, which is
  1040 already available via context of "advanced" translation.
  1041 
  1042 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
  1043 goal states; body tactic needs to address all subgoals uniformly.
  1044 
  1045 * Slightly more special eq_list/eq_set, with shortcut involving
  1046 pointer equality (assumes that eq relation is reflexive).
  1047 
  1048 * Classical tactics use proper Proof.context instead of historic types
  1049 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
  1050 operate directly on Proof.context.  Raw type claset retains its use as
  1051 snapshot of the classical context, which can be recovered via
  1052 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
  1053 INCOMPATIBILITY, classical tactics and derived proof methods require
  1054 proper Proof.context.
  1055 
  1056 
  1057 *** System ***
  1058 
  1059 * Discontinued support for Poly/ML 5.2, which was the last version
  1060 without proper multithreading and TimeLimit implementation.
  1061 
  1062 * Discontinued old lib/scripts/polyml-platform, which has been
  1063 obsolete since Isabelle2009-2.
  1064 
  1065 * Various optional external tools are referenced more robustly and
  1066 uniformly by explicit Isabelle settings as follows:
  1067 
  1068   ISABELLE_CSDP   (formerly CSDP_EXE)
  1069   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  1070   ISABELLE_OCAML  (formerly EXEC_OCAML)
  1071   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  1072   ISABELLE_YAP    (formerly EXEC_YAP)
  1073 
  1074 Note that automated detection from the file-system or search path has
  1075 been discontinued.  INCOMPATIBILITY.
  1076 
  1077 * Scala layer provides JVM method invocation service for static
  1078 methods of type (String)String, see Invoke_Scala.method in ML.  For
  1079 example:
  1080 
  1081   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
  1082 
  1083 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
  1084 this allows to pass structured values between ML and Scala.
  1085 
  1086 * The IsabelleText fonts includes some further glyphs to support the
  1087 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
  1088 installed a local copy (which is normally *not* required) need to
  1089 delete or update it from ~~/lib/fonts/.
  1090 
  1091 
  1092 
  1093 New in Isabelle2011 (January 2011)
  1094 ----------------------------------
  1095 
  1096 *** General ***
  1097 
  1098 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
  1099 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
  1100 useful tooltips and hyperlinks produced from its static analysis.  The
  1101 bundled component provides an executable Isabelle tool that can be run
  1102 like this:
  1103 
  1104   Isabelle2011/bin/isabelle jedit
  1105 
  1106 * Significantly improved Isabelle/Isar implementation manual.
  1107 
  1108 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
  1109 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
  1110 while the default heap location within that directory lacks that extra
  1111 suffix.  This isolates multiple Isabelle installations from each
  1112 other, avoiding problems with old settings in new versions.
  1113 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
  1114 
  1115 * Source files are always encoded as UTF-8, instead of old-fashioned
  1116 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
  1117 the following package declarations:
  1118 
  1119   \usepackage[utf8]{inputenc}
  1120   \usepackage{textcomp}
  1121 
  1122 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
  1123 a Unicode character is treated as a single symbol, not a sequence of
  1124 non-ASCII bytes as before.  Since Isabelle/ML string literals may
  1125 contain symbols without further backslash escapes, Unicode can now be
  1126 used here as well.  Recall that Symbol.explode in ML provides a
  1127 consistent view on symbols, while raw explode (or String.explode)
  1128 merely give a byte-oriented representation.
  1129 
  1130 * Theory loader: source files are primarily located via the master
  1131 directory of each theory node (where the .thy file itself resides).
  1132 The global load path is still partially available as legacy feature.
  1133 Minor INCOMPATIBILITY due to subtle change in file lookup: use
  1134 explicit paths, relatively to the theory.
  1135 
  1136 * Special treatment of ML file names has been discontinued.
  1137 Historically, optional extensions .ML or .sml were added on demand --
  1138 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
  1139 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
  1140 
  1141 * Various options that affect pretty printing etc. are now properly
  1142 handled within the context via configuration options, instead of
  1143 unsynchronized references or print modes.  There are both ML Config.T
  1144 entities and Isar declaration attributes to access these.
  1145 
  1146   ML (Config.T)                 Isar (attribute)
  1147 
  1148   eta_contract                  eta_contract
  1149   show_brackets                 show_brackets
  1150   show_sorts                    show_sorts
  1151   show_types                    show_types
  1152   show_question_marks           show_question_marks
  1153   show_consts                   show_consts
  1154   show_abbrevs                  show_abbrevs
  1155 
  1156   Syntax.ast_trace              syntax_ast_trace
  1157   Syntax.ast_stat               syntax_ast_stat
  1158   Syntax.ambiguity_level        syntax_ambiguity_level
  1159 
  1160   Goal_Display.goals_limit      goals_limit
  1161   Goal_Display.show_main_goal   show_main_goal
  1162 
  1163   Method.rule_trace             rule_trace
  1164 
  1165   Thy_Output.display            thy_output_display
  1166   Thy_Output.quotes             thy_output_quotes
  1167   Thy_Output.indent             thy_output_indent
  1168   Thy_Output.source             thy_output_source
  1169   Thy_Output.break              thy_output_break
  1170 
  1171 Note that corresponding "..._default" references in ML may only be
  1172 changed globally at the ROOT session setup, but *not* within a theory.
  1173 The option "show_abbrevs" supersedes the former print mode
  1174 "no_abbrevs" with inverted meaning.
  1175 
  1176 * More systematic naming of some configuration options.
  1177 INCOMPATIBILITY.
  1178 
  1179   trace_simp  ~>  simp_trace
  1180   debug_simp  ~>  simp_debug
  1181 
  1182 * Support for real valued configuration options, using simplistic
  1183 floating-point notation that coincides with the inner syntax for
  1184 float_token.
  1185 
  1186 * Support for real valued preferences (with approximative PGIP type):
  1187 front-ends need to accept "pgint" values in float notation.
  1188 INCOMPATIBILITY.
  1189 
  1190 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
  1191 DejaVu Sans.
  1192 
  1193 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
  1194 
  1195 
  1196 *** Pure ***
  1197 
  1198 * Command 'type_synonym' (with single argument) replaces somewhat
  1199 outdated 'types', which is still available as legacy feature for some
  1200 time.
  1201 
  1202 * Command 'nonterminal' (with 'and' separated list of arguments)
  1203 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
  1204 
  1205 * Command 'notepad' replaces former 'example_proof' for
  1206 experimentation in Isar without any result.  INCOMPATIBILITY.
  1207 
  1208 * Locale interpretation commands 'interpret' and 'sublocale' accept
  1209 lists of equations to map definitions in a locale to appropriate
  1210 entities in the context of the interpretation.  The 'interpretation'
  1211 command already provided this functionality.
  1212 
  1213 * Diagnostic command 'print_dependencies' prints the locale instances
  1214 that would be activated if the specified expression was interpreted in
  1215 the current context.  Variant "print_dependencies!" assumes a context
  1216 without interpretations.
  1217 
  1218 * Diagnostic command 'print_interps' prints interpretations in proofs
  1219 in addition to interpretations in theories.
  1220 
  1221 * Discontinued obsolete 'global' and 'local' commands to manipulate
  1222 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
  1223 Sign.root_path and Sign.local_path may be applied directly where this
  1224 feature is still required for historical reasons.
  1225 
  1226 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
  1227 'definition' instead.
  1228 
  1229 * The "prems" fact, which refers to the accidental collection of
  1230 foundational premises in the context, is now explicitly marked as
  1231 legacy feature and will be discontinued soon.  Consider using "assms"
  1232 of the head statement or reference facts by explicit names.
  1233 
  1234 * Document antiquotations @{class} and @{type} print classes and type
  1235 constructors.
  1236 
  1237 * Document antiquotation @{file} checks file/directory entries within
  1238 the local file system.
  1239 
  1240 
  1241 *** HOL ***
  1242 
  1243 * Coercive subtyping: functions can be declared as coercions and type
  1244 inference will add them as necessary upon input of a term.  Theory
  1245 Complex_Main declares real :: nat => real and real :: int => real as
  1246 coercions. A coercion function f is declared like this:
  1247 
  1248   declare [[coercion f]]
  1249 
  1250 To lift coercions through type constructors (e.g. from nat => real to
  1251 nat list => real list), map functions can be declared, e.g.
  1252 
  1253   declare [[coercion_map map]]
  1254 
  1255 Currently coercion inference is activated only in theories including
  1256 real numbers, i.e. descendants of Complex_Main.  This is controlled by
  1257 the configuration option "coercion_enabled", e.g. it can be enabled in
  1258 other theories like this:
  1259 
  1260   declare [[coercion_enabled]]
  1261 
  1262 * Command 'partial_function' provides basic support for recursive
  1263 function definitions over complete partial orders.  Concrete instances
  1264 are provided for i) the option type, ii) tail recursion on arbitrary
  1265 types, and iii) the heap monad of Imperative_HOL.  See
  1266 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1267 for examples.
  1268 
  1269 * Function package: f.psimps rules are no longer implicitly declared
  1270 as [simp].  INCOMPATIBILITY.
  1271 
  1272 * Datatype package: theorems generated for executable equality (class
  1273 "eq") carry proper names and are treated as default code equations.
  1274 
  1275 * Inductive package: now offers command 'inductive_simps' to
  1276 automatically derive instantiated and simplified equations for
  1277 inductive predicates, similar to 'inductive_cases'.
  1278 
  1279 * Command 'enriched_type' allows to register properties of the
  1280 functorial structure of types.
  1281 
  1282 * Improved infrastructure for term evaluation using code generator
  1283 techniques, in particular static evaluation conversions.
  1284 
  1285 * Code generator: Scala (2.8 or higher) has been added to the target
  1286 languages.
  1287 
  1288 * Code generator: globbing constant expressions "*" and "Theory.*"
  1289 have been replaced by the more idiomatic "_" and "Theory._".
  1290 INCOMPATIBILITY.
  1291 
  1292 * Code generator: export_code without explicit file declaration prints
  1293 to standard output.  INCOMPATIBILITY.
  1294 
  1295 * Code generator: do not print function definitions for case
  1296 combinators any longer.
  1297 
  1298 * Code generator: simplification with rules determined with
  1299 src/Tools/Code/code_simp.ML and method "code_simp".
  1300 
  1301 * Code generator for records: more idiomatic representation of record
  1302 types.  Warning: records are not covered by ancient SML code
  1303 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1304 rep_datatype declaration helps to succeed then:
  1305 
  1306   record 'a foo = ...
  1307   ...
  1308   rep_datatype foo_ext ...
  1309 
  1310 * Records: logical foundation type for records does not carry a
  1311 '_type' suffix any longer (obsolete due to authentic syntax).
  1312 INCOMPATIBILITY.
  1313 
  1314 * Quickcheck now by default uses exhaustive testing instead of random
  1315 testing.  Random testing can be invoked by "quickcheck [random]",
  1316 exhaustive testing by "quickcheck [exhaustive]".
  1317 
  1318 * Quickcheck instantiates polymorphic types with small finite
  1319 datatypes by default. This enables a simple execution mechanism to
  1320 handle quantifiers and function equality over the finite datatypes.
  1321 
  1322 * Quickcheck random generator has been renamed from "code" to
  1323 "random".  INCOMPATIBILITY.
  1324 
  1325 * Quickcheck now has a configurable time limit which is set to 30
  1326 seconds by default. This can be changed by adding [timeout = n] to the
  1327 quickcheck command. The time limit for Auto Quickcheck is still set
  1328 independently.
  1329 
  1330 * Quickcheck in locales considers interpretations of that locale for
  1331 counter example search.
  1332 
  1333 * Sledgehammer:
  1334   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1335     method. See the Sledgehammer manual for details ("isabelle doc
  1336     sledgehammer").
  1337   - Renamed commands:
  1338     sledgehammer atp_info ~> sledgehammer running_provers
  1339     sledgehammer atp_kill ~> sledgehammer kill_provers
  1340     sledgehammer available_atps ~> sledgehammer available_provers
  1341     INCOMPATIBILITY.
  1342   - Renamed options:
  1343     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1344     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1345     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1346     (and "ms" and "min" are no longer supported)
  1347     INCOMPATIBILITY.
  1348 
  1349 * Nitpick:
  1350   - Renamed options:
  1351     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1352     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1353     INCOMPATIBILITY.
  1354   - Added support for partial quotient types.
  1355   - Added local versions of the "Nitpick.register_xxx" functions.
  1356   - Added "whack" option.
  1357   - Allow registration of quotient types as codatatypes.
  1358   - Improved "merge_type_vars" option to merge more types.
  1359   - Removed unsound "fast_descrs" option.
  1360   - Added custom symmetry breaking for datatypes, making it possible to reach
  1361     higher cardinalities.
  1362   - Prevent the expansion of too large definitions.
  1363 
  1364 * Proof methods "metis" and "meson" now have configuration options
  1365 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1366 to diagnose these tools. E.g.
  1367 
  1368     using [[metis_trace = true]]
  1369 
  1370 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1371 manually as command 'solve_direct'.
  1372 
  1373 * The default SMT solver Z3 must be enabled explicitly (due to
  1374 licensing issues) by setting the environment variable
  1375 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1376 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1377 changing the SMT solver is done via the configuration option
  1378 "smt_solver".
  1379 
  1380 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1381 i.e. "remote_cvc3" and "remote_z3".
  1382 
  1383 * Added basic SMT support for datatypes, records, and typedefs using
  1384 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1385 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1386 support for a similar behavior).  Minor INCOMPATIBILITY.
  1387 
  1388 * Changed SMT configuration options:
  1389   - Renamed:
  1390     z3_proofs ~> smt_oracle (with inverted meaning)
  1391     z3_trace_assms ~> smt_trace_used_facts
  1392     INCOMPATIBILITY.
  1393   - Added:
  1394     smt_verbose
  1395     smt_random_seed
  1396     smt_datatypes
  1397     smt_infer_triggers
  1398     smt_monomorph_limit
  1399     cvc3_options
  1400     remote_cvc3_options
  1401     remote_z3_options
  1402     yices_options
  1403 
  1404 * Boogie output files (.b2i files) need to be declared in the theory
  1405 header.
  1406 
  1407 * Simplification procedure "list_to_set_comprehension" rewrites list
  1408 comprehensions applied to List.set to set comprehensions.  Occasional
  1409 INCOMPATIBILITY, may be deactivated like this:
  1410 
  1411   declare [[simproc del: list_to_set_comprehension]]
  1412 
  1413 * Removed old version of primrec package.  INCOMPATIBILITY.
  1414 
  1415 * Removed simplifier congruence rule of "prod_case", as has for long
  1416 been the case with "split".  INCOMPATIBILITY.
  1417 
  1418 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  1419 
  1420 * Removed [split_format ... and ... and ...] version of
  1421 [split_format].  Potential INCOMPATIBILITY.
  1422 
  1423 * Predicate "sorted" now defined inductively, with nice induction
  1424 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  1425 
  1426 * Constant "contents" renamed to "the_elem", to free the generic name
  1427 contents for other uses.  INCOMPATIBILITY.
  1428 
  1429 * Renamed class eq and constant eq (for code generation) to class
  1430 equal and constant equal, plus renaming of related facts and various
  1431 tuning.  INCOMPATIBILITY.
  1432 
  1433 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  1434 
  1435 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  1436 INCOMPATIBILITY.
  1437 
  1438 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  1439 avoid confusion with finite sets.  INCOMPATIBILITY.
  1440 
  1441 * Abandoned locales equiv, congruent and congruent2 for equivalence
  1442 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  1443 for congruent(2)).
  1444 
  1445 * Some previously unqualified names have been qualified:
  1446 
  1447   types
  1448     bool ~> HOL.bool
  1449     nat ~> Nat.nat
  1450 
  1451   constants
  1452     Trueprop ~> HOL.Trueprop
  1453     True ~> HOL.True
  1454     False ~> HOL.False
  1455     op & ~> HOL.conj
  1456     op | ~> HOL.disj
  1457     op --> ~> HOL.implies
  1458     op = ~> HOL.eq
  1459     Not ~> HOL.Not
  1460     The ~> HOL.The
  1461     All ~> HOL.All
  1462     Ex ~> HOL.Ex
  1463     Ex1 ~> HOL.Ex1
  1464     Let ~> HOL.Let
  1465     If ~> HOL.If
  1466     Ball ~> Set.Ball
  1467     Bex ~> Set.Bex
  1468     Suc ~> Nat.Suc
  1469     Pair ~> Product_Type.Pair
  1470     fst ~> Product_Type.fst
  1471     snd ~> Product_Type.snd
  1472     curry ~> Product_Type.curry
  1473     op : ~> Set.member
  1474     Collect ~> Set.Collect
  1475 
  1476 INCOMPATIBILITY.
  1477 
  1478 * More canonical naming convention for some fundamental definitions:
  1479 
  1480     bot_bool_eq ~> bot_bool_def
  1481     top_bool_eq ~> top_bool_def
  1482     inf_bool_eq ~> inf_bool_def
  1483     sup_bool_eq ~> sup_bool_def
  1484     bot_fun_eq  ~> bot_fun_def
  1485     top_fun_eq  ~> top_fun_def
  1486     inf_fun_eq  ~> inf_fun_def
  1487     sup_fun_eq  ~> sup_fun_def
  1488 
  1489 INCOMPATIBILITY.
  1490 
  1491 * More stylized fact names:
  1492 
  1493   expand_fun_eq ~> fun_eq_iff
  1494   expand_set_eq ~> set_eq_iff
  1495   set_ext       ~> set_eqI
  1496   nat_number    ~> eval_nat_numeral
  1497 
  1498 INCOMPATIBILITY.
  1499 
  1500 * Refactoring of code-generation specific operations in theory List:
  1501 
  1502   constants
  1503     null ~> List.null
  1504 
  1505   facts
  1506     mem_iff ~> member_def
  1507     null_empty ~> null_def
  1508 
  1509 INCOMPATIBILITY.  Note that these were not supposed to be used
  1510 regularly unless for striking reasons; their main purpose was code
  1511 generation.
  1512 
  1513 Various operations from the Haskell prelude are used for generating
  1514 Haskell code.
  1515 
  1516 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  1517 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  1518 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  1519 
  1520 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  1521 "*" and "+" respectively.  INCOMPATIBILITY.
  1522 
  1523 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  1524 "Sum_Type.Plus" instead.
  1525 
  1526 * Constant "split" has been merged with constant "prod_case"; names of
  1527 ML functions, facts etc. involving split have been retained so far,
  1528 though.  INCOMPATIBILITY.
  1529 
  1530 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  1531 instead.  INCOMPATIBILITY.
  1532 
  1533 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  1534 INCOMPATIBILITY.
  1535 
  1536 * Former theory Library/Enum is now part of the HOL-Main image.
  1537 INCOMPATIBILITY: all constants of the Enum theory now have to be
  1538 referred to by its qualified name.
  1539 
  1540   enum    ~>  Enum.enum
  1541   nlists  ~>  Enum.nlists
  1542   product ~>  Enum.product
  1543 
  1544 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  1545 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  1546 INCOMPATIBILITY.
  1547 
  1548 * Theory Library/SetsAndFunctions has been split into
  1549 Library/Function_Algebras and Library/Set_Algebras; canonical names
  1550 for instance definitions for functions; various improvements.
  1551 INCOMPATIBILITY.
  1552 
  1553 * Theory Library/Multiset provides stable quicksort implementation of
  1554 sort_key.
  1555 
  1556 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  1557 INCOMPATIBILITY.
  1558 
  1559 * Session Multivariate_Analysis: introduced a type class for euclidean
  1560 space.  Most theorems are now stated in terms of euclidean spaces
  1561 instead of finite cartesian products.
  1562 
  1563   types
  1564     real ^ 'n ~>  'a::real_vector
  1565               ~>  'a::euclidean_space
  1566               ~>  'a::ordered_euclidean_space
  1567         (depends on your needs)
  1568 
  1569   constants
  1570      _ $ _        ~> _ $$ _
  1571      \<chi> x. _  ~> \<chi>\<chi> x. _
  1572      CARD('n)     ~> DIM('a)
  1573 
  1574 Also note that the indices are now natural numbers and not from some
  1575 finite type. Finite cartesian products of euclidean spaces, products
  1576 of euclidean spaces the real and complex numbers are instantiated to
  1577 be euclidean_spaces.  INCOMPATIBILITY.
  1578 
  1579 * Session Probability: introduced pextreal as positive extended real
  1580 numbers.  Use pextreal as value for measures.  Introduce the
  1581 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  1582 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  1583 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  1584 
  1585 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  1586 INCOMPATIBILITY.
  1587 
  1588 * Session SPARK (with image HOL-SPARK) provides commands to load and
  1589 prove verification conditions generated by the SPARK Ada program
  1590 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  1591 
  1592 
  1593 *** HOL-Algebra ***
  1594 
  1595 * Theorems for additive ring operations (locale abelian_monoid and
  1596 descendants) are generated by interpretation from their multiplicative
  1597 counterparts.  Names (in particular theorem names) have the mandatory
  1598 qualifier 'add'.  Previous theorem names are redeclared for
  1599 compatibility.
  1600 
  1601 * Structure "int_ring" is now an abbreviation (previously a
  1602 definition).  This fits more natural with advanced interpretations.
  1603 
  1604 
  1605 *** HOLCF ***
  1606 
  1607 * The domain package now runs in definitional mode by default: The
  1608 former command 'new_domain' is now called 'domain'.  To use the domain
  1609 package in its original axiomatic mode, use 'domain (unsafe)'.
  1610 INCOMPATIBILITY.
  1611 
  1612 * The new class "domain" is now the default sort.  Class "predomain"
  1613 is an unpointed version of "domain". Theories can be updated by
  1614 replacing sort annotations as shown below.  INCOMPATIBILITY.
  1615 
  1616   'a::type ~> 'a::countable
  1617   'a::cpo  ~> 'a::predomain
  1618   'a::pcpo ~> 'a::domain
  1619 
  1620 * The old type class "rep" has been superseded by class "domain".
  1621 Accordingly, users of the definitional package must remove any
  1622 "default_sort rep" declarations.  INCOMPATIBILITY.
  1623 
  1624 * The domain package (definitional mode) now supports unpointed
  1625 predomain argument types, as long as they are marked 'lazy'. (Strict
  1626 arguments must be in class "domain".) For example, the following
  1627 domain definition now works:
  1628 
  1629   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  1630 
  1631 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  1632 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  1633 'a option, and 'a list.  Additionally, it configures fixrec and the
  1634 domain package to work with these types.  For example:
  1635 
  1636   fixrec isInl :: "('a + 'b) u -> tr"
  1637     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  1638 
  1639   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  1640 
  1641 * The "(permissive)" option of fixrec has been replaced with a
  1642 per-equation "(unchecked)" option. See
  1643 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  1644 
  1645 * The "bifinite" class no longer fixes a constant "approx"; the class
  1646 now just asserts that such a function exists.  INCOMPATIBILITY.
  1647 
  1648 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  1649 defines an embedding of type 'a defl into udom by default; instances
  1650 of "bifinite" and "domain" classes are available in
  1651 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  1652 
  1653 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  1654 
  1655 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  1656 
  1657 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  1658 
  1659 * The function "cprod_map" has been renamed to "prod_map".
  1660 INCOMPATIBILITY.
  1661 
  1662 * The monadic bind operator on each powerdomain has new binder syntax
  1663 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  1664 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  1665 
  1666 * The infix syntax for binary union on each powerdomain has changed
  1667 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  1668 syntax.  INCOMPATIBILITY.
  1669 
  1670 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  1671 still supported as an input translation.
  1672 
  1673 * Renamed some theorems (the original names are also still available).
  1674 
  1675   expand_fun_below   ~> fun_below_iff
  1676   below_fun_ext      ~> fun_belowI
  1677   expand_cfun_eq     ~> cfun_eq_iff
  1678   ext_cfun           ~> cfun_eqI
  1679   expand_cfun_below  ~> cfun_below_iff
  1680   below_cfun_ext     ~> cfun_belowI
  1681   cont2cont_Rep_CFun ~> cont2cont_APP
  1682 
  1683 * The Abs and Rep functions for various types have changed names.
  1684 Related theorem names have also changed to match. INCOMPATIBILITY.
  1685 
  1686   Rep_CFun  ~> Rep_cfun
  1687   Abs_CFun  ~> Abs_cfun
  1688   Rep_Sprod ~> Rep_sprod
  1689   Abs_Sprod ~> Abs_sprod
  1690   Rep_Ssum  ~> Rep_ssum
  1691   Abs_Ssum  ~> Abs_ssum
  1692 
  1693 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  1694 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  1695 
  1696 * Various changes to bisimulation/coinduction with domain package:
  1697 
  1698   - Definitions of "bisim" constants no longer mention definedness.
  1699   - With mutual recursion, "bisim" predicate is now curried.
  1700   - With mutual recursion, each type gets a separate coind theorem.
  1701   - Variable names in bisim_def and coinduct rules have changed.
  1702 
  1703 INCOMPATIBILITY.
  1704 
  1705 * Case combinators generated by the domain package for type "foo" are
  1706 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  1707 
  1708 * Several theorems have been renamed to more accurately reflect the
  1709 names of constants and types involved.  INCOMPATIBILITY.
  1710 
  1711   thelub_const    ~> lub_const
  1712   lub_const       ~> is_lub_const
  1713   thelubI         ~> lub_eqI
  1714   is_lub_lub      ~> is_lubD2
  1715   lubI            ~> is_lub_lub
  1716   unique_lub      ~> is_lub_unique
  1717   is_ub_lub       ~> is_lub_rangeD1
  1718   lub_bin_chain   ~> is_lub_bin_chain
  1719   lub_fun         ~> is_lub_fun
  1720   thelub_fun      ~> lub_fun
  1721   thelub_cfun     ~> lub_cfun
  1722   thelub_Pair     ~> lub_Pair
  1723   lub_cprod       ~> is_lub_prod
  1724   thelub_cprod    ~> lub_prod
  1725   minimal_cprod   ~> minimal_prod
  1726   inst_cprod_pcpo ~> inst_prod_pcpo
  1727   UU_I            ~> bottomI
  1728   compact_UU      ~> compact_bottom
  1729   deflation_UU    ~> deflation_bottom
  1730   finite_deflation_UU ~> finite_deflation_bottom
  1731 
  1732 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  1733 
  1734   sq_ord_less_eq_trans ~> below_eq_trans
  1735   sq_ord_eq_less_trans ~> eq_below_trans
  1736   refl_less            ~> below_refl
  1737   trans_less           ~> below_trans
  1738   antisym_less         ~> below_antisym
  1739   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  1740   box_less             ~> box_below
  1741   rev_trans_less       ~> rev_below_trans
  1742   not_less2not_eq      ~> not_below2not_eq
  1743   less_UU_iff          ~> below_UU_iff
  1744   flat_less_iff        ~> flat_below_iff
  1745   adm_less             ~> adm_below
  1746   adm_not_less         ~> adm_not_below
  1747   adm_compact_not_less ~> adm_compact_not_below
  1748   less_fun_def         ~> below_fun_def
  1749   expand_fun_less      ~> fun_below_iff
  1750   less_fun_ext         ~> fun_belowI
  1751   less_discr_def       ~> below_discr_def
  1752   discr_less_eq        ~> discr_below_eq
  1753   less_unit_def        ~> below_unit_def
  1754   less_cprod_def       ~> below_prod_def
  1755   prod_lessI           ~> prod_belowI
  1756   Pair_less_iff        ~> Pair_below_iff
  1757   fst_less_iff         ~> fst_below_iff
  1758   snd_less_iff         ~> snd_below_iff
  1759   expand_cfun_less     ~> cfun_below_iff
  1760   less_cfun_ext        ~> cfun_belowI
  1761   injection_less       ~> injection_below
  1762   less_up_def          ~> below_up_def
  1763   not_Iup_less         ~> not_Iup_below
  1764   Iup_less             ~> Iup_below
  1765   up_less              ~> up_below
  1766   Def_inject_less_eq   ~> Def_below_Def
  1767   Def_less_is_eq       ~> Def_below_iff
  1768   spair_less_iff       ~> spair_below_iff
  1769   less_sprod           ~> below_sprod
  1770   spair_less           ~> spair_below
  1771   sfst_less_iff        ~> sfst_below_iff
  1772   ssnd_less_iff        ~> ssnd_below_iff
  1773   fix_least_less       ~> fix_least_below
  1774   dist_less_one        ~> dist_below_one
  1775   less_ONE             ~> below_ONE
  1776   ONE_less_iff         ~> ONE_below_iff
  1777   less_sinlD           ~> below_sinlD
  1778   less_sinrD           ~> below_sinrD
  1779 
  1780 
  1781 *** FOL and ZF ***
  1782 
  1783 * All constant names are now qualified internally and use proper
  1784 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  1785 
  1786 *** ZF ***
  1787 
  1788 * Greater support for structured proofs involving induction or case analysis.
  1789 
  1790 * Much greater use of special symbols.
  1791 
  1792 * Removal of many ML theorem bindings. INCOMPATIBILITY.
  1793 
  1794 *** ML ***
  1795 
  1796 * Antiquotation @{assert} inlines a function bool -> unit that raises
  1797 Fail if the argument is false.  Due to inlining the source position of
  1798 failed assertions is included in the error output.
  1799 
  1800 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  1801 text is in practice always evaluated with a stable theory checkpoint.
  1802 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  1803 
  1804 * Antiquotation @{theory A} refers to theory A from the ancestry of
  1805 the current context, not any accidental theory loader state as before.
  1806 Potential INCOMPATIBILITY, subtle change in semantics.
  1807 
  1808 * Syntax.pretty_priority (default 0) configures the required priority
  1809 of pretty-printed output and thus affects insertion of parentheses.
  1810 
  1811 * Syntax.default_root (default "any") configures the inner syntax
  1812 category (nonterminal symbol) for parsing of terms.
  1813 
  1814 * Former exception Library.UnequalLengths now coincides with
  1815 ListPair.UnequalLengths.
  1816 
  1817 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1818 main functionality is provided by structure Simplifier.
  1819 
  1820 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1821 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1822 almost all situations.
  1823 
  1824 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1825 See implementation manual for further details on exceptions in
  1826 Isabelle/ML.
  1827 
  1828 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1829 meaning.
  1830 
  1831 * Renamed structure PureThy to Pure_Thy and moved most of its
  1832 operations to structure Global_Theory, to emphasize that this is
  1833 rarely-used global-only stuff.
  1834 
  1835 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1836 instead (or tracing for high-volume output).
  1837 
  1838 * Configuration option show_question_marks only affects regular pretty
  1839 printing of types and terms, not raw Term.string_of_vname.
  1840 
  1841 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1842 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1843 @{thms} for most purposes.
  1844 
  1845 * ML structure Unsynchronized is never opened, not even in Isar
  1846 interaction mode as before.  Old Unsynchronized.set etc. have been
  1847 discontinued -- use plain := instead.  This should be *rare* anyway,
  1848 since modern tools always work via official context data, notably
  1849 configuration options.
  1850 
  1851 * Parallel and asynchronous execution requires special care concerning
  1852 interrupts.  Structure Exn provides some convenience functions that
  1853 avoid working directly with raw Interrupt.  User code must not absorb
  1854 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1855 followed by re-raising of the original exception.  Another common
  1856 source of mistakes are "handle _" patterns, which make the meaning of
  1857 the program subject to physical effects of the environment.
  1858 
  1859 
  1860 
  1861 New in Isabelle2009-2 (June 2010)
  1862 ---------------------------------
  1863 
  1864 *** General ***
  1865 
  1866 * Authentic syntax for *all* logical entities (type classes, type
  1867 constructors, term constants): provides simple and robust
  1868 correspondence between formal entities and concrete syntax.  Within
  1869 the parse tree / AST representations, "constants" are decorated by
  1870 their category (class, type, const) and spelled out explicitly with
  1871 their full internal name.
  1872 
  1873 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1874 and translations (translation rules and translation functions in ML).
  1875 Some hints on upgrading:
  1876 
  1877   - Many existing uses of 'syntax' and 'translations' can be replaced
  1878     by more modern 'type_notation', 'notation' and 'abbreviation',
  1879     which are independent of this issue.
  1880 
  1881   - 'translations' require markup within the AST; the term syntax
  1882     provides the following special forms:
  1883 
  1884       CONST c   -- produces syntax version of constant c from context
  1885       XCONST c  -- literally c, checked as constant from context
  1886       c         -- literally c, if declared by 'syntax'
  1887 
  1888     Plain identifiers are treated as AST variables -- occasionally the
  1889     system indicates accidental variables via the error "rhs contains
  1890     extra variables".
  1891 
  1892     Type classes and type constructors are marked according to their
  1893     concrete syntax.  Some old translations rules need to be written
  1894     for the "type" category, using type constructor application
  1895     instead of pseudo-term application of the default category
  1896     "logic".
  1897 
  1898   - 'parse_translation' etc. in ML may use the following
  1899     antiquotations:
  1900 
  1901       @{class_syntax c}   -- type class c within parse tree / AST
  1902       @{term_syntax c}    -- type constructor c within parse tree / AST
  1903       @{const_syntax c}   -- ML version of "CONST c" above
  1904       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1905 
  1906   - Literal types within 'typed_print_translations', i.e. those *not*
  1907     represented as pseudo-terms are represented verbatim.  Use @{class
  1908     c} or @{type_name c} here instead of the above syntax
  1909     antiquotations.
  1910 
  1911 Note that old non-authentic syntax was based on unqualified base
  1912 names, so all of the above "constant" names would coincide.  Recall
  1913 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1914 diagnose syntax problems.
  1915 
  1916 * Type constructors admit general mixfix syntax, not just infix.
  1917 
  1918 * Concrete syntax may be attached to local entities without a proof
  1919 body, too.  This works via regular mixfix annotations for 'fix',
  1920 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1921 similar to the 'notation' command in theory specifications.
  1922 
  1923 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1924 need to specify constant name and syntax separately.  Internal ML
  1925 datatype constructors have been renamed from InfixName to Infix etc.
  1926 Minor INCOMPATIBILITY.
  1927 
  1928 * Schematic theorem statements need to be explicitly markup as such,
  1929 via commands 'schematic_lemma', 'schematic_theorem',
  1930 'schematic_corollary'.  Thus the relevance of the proof is made
  1931 syntactically clear, which impacts performance in a parallel or
  1932 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1933 
  1934 * Use of cumulative prems via "!" in some proof methods has been
  1935 discontinued (old legacy feature).
  1936 
  1937 * References 'trace_simp' and 'debug_simp' have been replaced by
  1938 configuration options stored in the context. Enabling tracing (the
  1939 case of debugging is similar) in proofs works via
  1940 
  1941   using [[trace_simp = true]]
  1942 
  1943 Tracing is then active for all invocations of the simplifier in
  1944 subsequent goal refinement steps. Tracing may also still be enabled or
  1945 disabled via the ProofGeneral settings menu.
  1946 
  1947 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1948 'hide_fact' replace the former 'hide' KIND command.  Minor
  1949 INCOMPATIBILITY.
  1950 
  1951 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1952 more efficient than combinations with -q1 or -q2.
  1953 
  1954 
  1955 *** Pure ***
  1956 
  1957 * Proofterms record type-class reasoning explicitly, using the
  1958 "unconstrain" operation internally.  This eliminates all sort
  1959 constraints from a theorem and proof, introducing explicit
  1960 OFCLASS-premises.  On the proof term level, this operation is
  1961 automatically applied at theorem boundaries, such that closed proofs
  1962 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1963 inspect proof terms.
  1964 
  1965 * Local theory specifications may depend on extra type variables that
  1966 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1967 are added internally.  For example:
  1968 
  1969   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1970 
  1971 * Predicates of locales introduced by classes carry a mandatory
  1972 "class" prefix.  INCOMPATIBILITY.
  1973 
  1974 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1975 
  1976 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1977 'class' instead.
  1978 
  1979 * Command 'code_reflect' allows to incorporate generated ML code into
  1980 runtime environment; replaces immature code_datatype antiquotation.
  1981 INCOMPATIBILITY.
  1982 
  1983 * Code generator: simple concept for abstract datatypes obeying
  1984 invariants.
  1985 
  1986 * Code generator: details of internal data cache have no impact on the
  1987 user space functionality any longer.
  1988 
  1989 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1990 subgoals.  This is more appropriate for interpretations with 'where'.
  1991 INCOMPATIBILITY.
  1992 
  1993 * Command 'example_proof' opens an empty proof body.  This allows to
  1994 experiment with Isar, without producing any persistent result.
  1995 
  1996 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1997 within a local theory context, with explicit checking of the
  1998 constructors involved (in contrast to the raw 'syntax' versions).
  1999 
  2000 * Commands 'types' and 'typedecl' now work within a local theory
  2001 context -- without introducing dependencies on parameters or
  2002 assumptions, which is not possible in Isabelle/Pure.
  2003 
  2004 * Command 'defaultsort' has been renamed to 'default_sort', it works
  2005 within a local theory context.  Minor INCOMPATIBILITY.
  2006 
  2007 
  2008 *** HOL ***
  2009 
  2010 * Command 'typedef' now works within a local theory context -- without
  2011 introducing dependencies on parameters or assumptions, which is not
  2012 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  2013 contain multiple interpretations of local typedefs (with different
  2014 non-emptiness proofs), even in a global theory context.
  2015 
  2016 * New package for quotient types.  Commands 'quotient_type' and
  2017 'quotient_definition' may be used for defining types and constants by
  2018 quotient constructions.  An example is the type of integers created by
  2019 quotienting pairs of natural numbers:
  2020 
  2021   fun
  2022     intrel :: "(nat * nat) => (nat * nat) => bool"
  2023   where
  2024     "intrel (x, y) (u, v) = (x + v = u + y)"
  2025 
  2026   quotient_type int = "nat * nat" / intrel
  2027     by (auto simp add: equivp_def expand_fun_eq)
  2028 
  2029   quotient_definition
  2030     "0::int" is "(0::nat, 0::nat)"
  2031 
  2032 The method "lifting" can be used to lift of theorems from the
  2033 underlying "raw" type to the quotient type.  The example
  2034 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  2035 construction and provides a reasoning infrastructure for finite sets.
  2036 
  2037 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  2038 clash with new theory Quotient in Main HOL.
  2039 
  2040 * Moved the SMT binding into the main HOL session, eliminating
  2041 separate HOL-SMT session.
  2042 
  2043 * List membership infix mem operation is only an input abbreviation.
  2044 INCOMPATIBILITY.
  2045 
  2046 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  2047 for future developements; former Library/Word.thy is still present in
  2048 the AFP entry RSAPPS.
  2049 
  2050 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  2051 longer shadowed.  INCOMPATIBILITY.
  2052 
  2053 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  2054 INCOMPATIBILITY.
  2055 
  2056 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  2057 INCOMPATIBILITY.
  2058 
  2059 * Dropped normalizing_semiring etc; use the facts in semiring classes
  2060 instead.  INCOMPATIBILITY.
  2061 
  2062 * Dropped several real-specific versions of lemmas about floor and
  2063 ceiling; use the generic lemmas from theory "Archimedean_Field"
  2064 instead.  INCOMPATIBILITY.
  2065 
  2066   floor_number_of_eq         ~> floor_number_of
  2067   le_floor_eq_number_of      ~> number_of_le_floor
  2068   le_floor_eq_zero           ~> zero_le_floor
  2069   le_floor_eq_one            ~> one_le_floor
  2070   floor_less_eq_number_of    ~> floor_less_number_of
  2071   floor_less_eq_zero         ~> floor_less_zero
  2072   floor_less_eq_one          ~> floor_less_one
  2073   less_floor_eq_number_of    ~> number_of_less_floor
  2074   less_floor_eq_zero         ~> zero_less_floor
  2075   less_floor_eq_one          ~> one_less_floor
  2076   floor_le_eq_number_of      ~> floor_le_number_of
  2077   floor_le_eq_zero           ~> floor_le_zero
  2078   floor_le_eq_one            ~> floor_le_one
  2079   floor_subtract_number_of   ~> floor_diff_number_of
  2080   floor_subtract_one         ~> floor_diff_one
  2081   ceiling_number_of_eq       ~> ceiling_number_of
  2082   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  2083   ceiling_le_zero_eq         ~> ceiling_le_zero
  2084   ceiling_le_eq_one          ~> ceiling_le_one
  2085   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  2086   less_ceiling_eq_zero       ~> zero_less_ceiling
  2087   less_ceiling_eq_one        ~> one_less_ceiling
  2088   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  2089   ceiling_less_eq_zero       ~> ceiling_less_zero
  2090   ceiling_less_eq_one        ~> ceiling_less_one
  2091   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  2092   le_ceiling_eq_zero         ~> zero_le_ceiling
  2093   le_ceiling_eq_one          ~> one_le_ceiling
  2094   ceiling_subtract_number_of ~> ceiling_diff_number_of
  2095   ceiling_subtract_one       ~> ceiling_diff_one
  2096 
  2097 * Theory "Finite_Set": various folding_XXX locales facilitate the
  2098 application of the various fold combinators on finite sets.
  2099 
  2100 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  2101 provides abstract red-black tree type which is backed by "RBT_Impl" as
  2102 implementation.  INCOMPATIBILTY.
  2103 
  2104 * Theory Library/Coinductive_List has been removed -- superseded by
  2105 AFP/thys/Coinductive.
  2106 
  2107 * Theory PReal, including the type "preal" and related operations, has
  2108 been removed.  INCOMPATIBILITY.
  2109 
  2110 * Real: new development using Cauchy Sequences.
  2111 
  2112 * Split off theory "Big_Operators" containing setsum, setprod,
  2113 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  2114 
  2115 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  2116 "Int" etc.  INCOMPATIBILITY.
  2117 
  2118 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  2119 
  2120 * New set of rules "ac_simps" provides combined assoc / commute
  2121 rewrites for all interpretations of the appropriate generic locales.
  2122 
  2123 * Renamed theory "OrderedGroup" to "Groups" and split theory
  2124 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  2125 appropriate and more consistent names suitable for name prefixes
  2126 within the HOL theories.  INCOMPATIBILITY.
  2127 
  2128 * Some generic constants have been put to appropriate theories:
  2129   - less_eq, less: Orderings
  2130   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  2131   - inverse, divide: Rings
  2132 INCOMPATIBILITY.
  2133 
  2134 * More consistent naming of type classes involving orderings (and
  2135 lattices):
  2136 
  2137     lower_semilattice                   ~> semilattice_inf
  2138     upper_semilattice                   ~> semilattice_sup
  2139 
  2140     dense_linear_order                  ~> dense_linorder
  2141 
  2142     pordered_ab_group_add               ~> ordered_ab_group_add
  2143     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  2144     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  2145     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  2146     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  2147     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  2148     pordered_cancel_semiring            ~> ordered_cancel_semiring
  2149     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  2150     pordered_comm_ring                  ~> ordered_comm_ring
  2151     pordered_comm_semiring              ~> ordered_comm_semiring
  2152     pordered_ring                       ~> ordered_ring
  2153     pordered_ring_abs                   ~> ordered_ring_abs
  2154     pordered_semiring                   ~> ordered_semiring
  2155 
  2156     ordered_ab_group_add                ~> linordered_ab_group_add
  2157     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  2158     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  2159     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  2160     ordered_field                       ~> linordered_field
  2161     ordered_field_no_lb                 ~> linordered_field_no_lb
  2162     ordered_field_no_ub                 ~> linordered_field_no_ub
  2163     ordered_field_dense_linear_order    ~> dense_linordered_field
  2164     ordered_idom                        ~> linordered_idom
  2165     ordered_ring                        ~> linordered_ring
  2166     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  2167     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  2168     ordered_ring_strict                 ~> linordered_ring_strict
  2169     ordered_semidom                     ~> linordered_semidom
  2170     ordered_semiring                    ~> linordered_semiring
  2171     ordered_semiring_1                  ~> linordered_semiring_1
  2172     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  2173     ordered_semiring_strict             ~> linordered_semiring_strict
  2174 
  2175   The following slightly odd type classes have been moved to a
  2176   separate theory Library/Lattice_Algebras:
  2177 
  2178     lordered_ab_group_add               ~> lattice_ab_group_add
  2179     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  2180     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  2181     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  2182     lordered_ring                       ~> lattice_ring
  2183 
  2184 INCOMPATIBILITY.
  2185 
  2186 * Refined field classes:
  2187   - classes division_ring_inverse_zero, field_inverse_zero,
  2188     linordered_field_inverse_zero include rule inverse 0 = 0 --
  2189     subsumes former division_by_zero class;
  2190   - numerous lemmas have been ported from field to division_ring.
  2191 INCOMPATIBILITY.
  2192 
  2193 * Refined algebra theorem collections:
  2194   - dropped theorem group group_simps, use algebra_simps instead;
  2195   - dropped theorem group ring_simps, use field_simps instead;
  2196   - proper theorem collection field_simps subsumes former theorem
  2197     groups field_eq_simps and field_simps;
  2198   - dropped lemma eq_minus_self_iff which is a duplicate for
  2199     equal_neg_zero.
  2200 INCOMPATIBILITY.
  2201 
  2202 * Theory Finite_Set and List: some lemmas have been generalized from
  2203 sets to lattices:
  2204 
  2205   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  2206   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  2207   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  2208   union_Union_fold_union        ~> sup_Sup_fold_sup
  2209   Inter_fold_inter              ~> Inf_fold_inf
  2210   Union_fold_union              ~> Sup_fold_sup
  2211   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  2212   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  2213   INTER_fold_inter              ~> INFI_fold_inf
  2214   UNION_fold_union              ~> SUPR_fold_sup
  2215 
  2216 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  2217 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  2218 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  2219 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  2220 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  2221 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  2222 
  2223 * Reorganized theory Multiset: swapped notation of pointwise and
  2224 multiset order:
  2225 
  2226   - pointwise ordering is instance of class order with standard syntax
  2227     <= and <;
  2228   - multiset ordering has syntax <=# and <#; partial order properties
  2229     are provided by means of interpretation with prefix
  2230     multiset_order;
  2231   - less duplication, less historical organization of sections,
  2232     conversion from associations lists to multisets, rudimentary code
  2233     generation;
  2234   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  2235     if needed.
  2236 
  2237 Renamed:
  2238 
  2239   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  2240   multi_count_ext  ~>  multiset_ext
  2241   diff_union_inverse2  ~>  diff_union_cancelR
  2242 
  2243 INCOMPATIBILITY.
  2244 
  2245 * Theory Permutation: replaced local "remove" by List.remove1.
  2246 
  2247 * Code generation: ML and OCaml code is decorated with signatures.
  2248 
  2249 * Theory List: added transpose.
  2250 
  2251 * Library/Nat_Bijection.thy is a collection of bijective functions
  2252 between nat and other types, which supersedes the older libraries
  2253 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  2254 
  2255   Constants:
  2256   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  2257   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  2258   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  2259   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  2260   Countable.pair_encode           ~> prod_encode
  2261   NatIso.prod2nat                 ~> prod_encode
  2262   NatIso.nat2prod                 ~> prod_decode
  2263   NatIso.sum2nat                  ~> sum_encode
  2264   NatIso.nat2sum                  ~> sum_decode
  2265   NatIso.list2nat                 ~> list_encode
  2266   NatIso.nat2list                 ~> list_decode
  2267   NatIso.set2nat                  ~> set_encode
  2268   NatIso.nat2set                  ~> set_decode
  2269 
  2270   Lemmas:
  2271   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2272   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2273   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2274   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2275   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2276   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2277   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2278   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2279   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2280   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2281   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2282   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2283   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2284 
  2285 * Sledgehammer:
  2286   - Renamed ATP commands:
  2287     atp_info     ~> sledgehammer running_atps
  2288     atp_kill     ~> sledgehammer kill_atps
  2289     atp_messages ~> sledgehammer messages
  2290     atp_minimize ~> sledgehammer minimize
  2291     print_atps   ~> sledgehammer available_atps
  2292     INCOMPATIBILITY.
  2293   - Added user's manual ("isabelle doc sledgehammer").
  2294   - Added option syntax and "sledgehammer_params" to customize
  2295     Sledgehammer's behavior.  See the manual for details.
  2296   - Modified the Isar proof reconstruction code so that it produces
  2297     direct proofs rather than proofs by contradiction.  (This feature
  2298     is still experimental.)
  2299   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2300     full-typed mode.
  2301   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2302 
  2303 * Nitpick:
  2304   - Added and implemented "binary_ints" and "bits" options.
  2305   - Added "std" option and implemented support for nonstandard models.
  2306   - Added and implemented "finitize" option to improve the precision
  2307     of infinite datatypes based on a monotonicity analysis.
  2308   - Added support for quotient types.
  2309   - Added support for "specification" and "ax_specification"
  2310     constructs.
  2311   - Added support for local definitions (for "function" and
  2312     "termination" proofs).
  2313   - Added support for term postprocessors.
  2314   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2315   - Improved efficiency of "destroy_constrs" optimization.
  2316   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2317     record getters.
  2318   - Fixed soundness bug related to higher-order constructors.
  2319   - Fixed soundness bug when "full_descrs" is enabled.
  2320   - Improved precision of set constructs.
  2321   - Added "atoms" option.
  2322   - Added cache to speed up repeated Kodkod invocations on the same
  2323     problems.
  2324   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2325     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2326     "SAT4J_Light".  INCOMPATIBILITY.
  2327   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2328     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2329   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2330 
  2331 * Method "induct" now takes instantiations of the form t, where t is not
  2332   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2333   If this is not intended, t has to be enclosed in parentheses.
  2334   By default, the equalities generated by definitional instantiations
  2335   are pre-simplified, which may cause parameters of inductive cases
  2336   to disappear, or may even delete some of the inductive cases.
  2337   Use "induct (no_simp)" instead of "induct" to restore the old
  2338   behaviour. The (no_simp) option is also understood by the "cases"
  2339   and "nominal_induct" methods, which now perform pre-simplification, too.
  2340   INCOMPATIBILITY.
  2341 
  2342 
  2343 *** HOLCF ***
  2344 
  2345 * Variable names in lemmas generated by the domain package have
  2346 changed; the naming scheme is now consistent with the HOL datatype
  2347 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2348 
  2349 * The domain package no longer defines the function "foo_copy" for
  2350 recursive domain "foo".  The reach lemma is now stated directly in
  2351 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2352 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2353 
  2354 * Most definedness lemmas generated by the domain package (previously
  2355 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2356 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2357 Proofs that used definedness lemmas as intro rules may break,
  2358 potential INCOMPATIBILITY.
  2359 
  2360 * Induction and casedist rules generated by the domain package now
  2361 declare proper case_names (one called "bottom", and one named for each
  2362 constructor).  INCOMPATIBILITY.
  2363 
  2364 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2365 rules are generated for each domain, INCOMPATIBILITY.
  2366 
  2367   foo_bar.reach       ~> foo.reach  bar.reach
  2368   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2369 
  2370 * Some lemmas generated by the domain package have been renamed for
  2371 consistency with the datatype package, INCOMPATIBILITY.
  2372 
  2373   foo.ind        ~> foo.induct
  2374   foo.finite_ind ~> foo.finite_induct
  2375   foo.coind      ~> foo.coinduct
  2376   foo.casedist   ~> foo.exhaust
  2377   foo.exhaust    ~> foo.nchotomy
  2378 
  2379 * For consistency with other definition packages, the fixrec package
  2380 now generates qualified theorem names, INCOMPATIBILITY.
  2381 
  2382   foo_simps  ~> foo.simps
  2383   foo_unfold ~> foo.unfold
  2384   foo_induct ~> foo.induct
  2385 
  2386 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2387 method and internal fixrec proofs now use the default simpset instead.
  2388 INCOMPATIBILITY.
  2389 
  2390 * The "contlub" predicate has been removed.  Proof scripts should use
  2391 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2392 
  2393 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2394 
  2395 * The constants cpair, cfst, and csnd have been removed in favor of
  2396 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2397 
  2398 
  2399 *** ML ***
  2400 
  2401 * Antiquotations for basic formal entities:
  2402 
  2403     @{class NAME}         -- type class
  2404     @{class_syntax NAME}  -- syntax representation of the above
  2405 
  2406     @{type_name NAME}     -- logical type
  2407     @{type_abbrev NAME}   -- type abbreviation
  2408     @{nonterminal NAME}   -- type of concrete syntactic category
  2409     @{type_syntax NAME}   -- syntax representation of any of the above
  2410 
  2411     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2412     @{const_abbrev NAME}  -- abbreviated constant
  2413     @{const_syntax NAME}  -- syntax representation of any of the above
  2414 
  2415 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  2416 syntax constant (cf. 'syntax' command).
  2417 
  2418 * Antiquotation @{make_string} inlines a function to print arbitrary
  2419 values similar to the ML toplevel.  The result is compiler dependent
  2420 and may fall back on "?" in certain situations.
  2421 
  2422 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  2423 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  2424 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  2425 not work with the asynchronous Isar document model.
  2426 
  2427 * Configuration options now admit dynamic default values, depending on
  2428 the context or even global references.
  2429 
  2430 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  2431 uses an efficient external library if available (for Poly/ML).
  2432 
  2433 * Renamed some important ML structures, while keeping the old names
  2434 for some time as aliases within the structure Legacy:
  2435 
  2436   OuterKeyword  ~>  Keyword
  2437   OuterLex      ~>  Token
  2438   OuterParse    ~>  Parse
  2439   OuterSyntax   ~>  Outer_Syntax
  2440   PrintMode     ~>  Print_Mode
  2441   SpecParse     ~>  Parse_Spec
  2442   ThyInfo       ~>  Thy_Info
  2443   ThyLoad       ~>  Thy_Load
  2444   ThyOutput     ~>  Thy_Output
  2445   TypeInfer     ~>  Type_Infer
  2446 
  2447 Note that "open Legacy" simplifies porting of sources, but forgetting
  2448 to remove it again will complicate porting again in the future.
  2449 
  2450 * Most operations that refer to a global context are named
  2451 accordingly, e.g. Simplifier.global_context or
  2452 ProofContext.init_global.  There are some situations where a global
  2453 context actually works, but under normal circumstances one needs to
  2454 pass the proper local context through the code!
  2455 
  2456 * Discontinued old TheoryDataFun with its copy/init operation -- data
  2457 needs to be pure.  Functor Theory_Data_PP retains the traditional
  2458 Pretty.pp argument to merge, which is absent in the standard
  2459 Theory_Data version.
  2460 
  2461 * Sorts.certify_sort and derived "cert" operations for types and terms
  2462 no longer minimize sorts.  Thus certification at the boundary of the
  2463 inference kernel becomes invariant under addition of class relations,
  2464 which is an important monotonicity principle.  Sorts are now minimized
  2465 in the syntax layer only, at the boundary between the end-user and the
  2466 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  2467 explicitly in rare situations.
  2468 
  2469 * Renamed old-style Drule.standard to Drule.export_without_context, to
  2470 emphasize that this is in no way a standard operation.
  2471 INCOMPATIBILITY.
  2472 
  2473 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  2474 usual for resolution.  Rare INCOMPATIBILITY.
  2475 
  2476 * Renamed varify/unvarify operations to varify_global/unvarify_global
  2477 to emphasize that these only work in a global situation (which is
  2478 quite rare).
  2479 
  2480 * Curried take and drop in library.ML; negative length is interpreted
  2481 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  2482 
  2483 * Proof terms: type substitutions on proof constants now use canonical
  2484 order of type variables.  INCOMPATIBILITY for tools working with proof
  2485 terms.
  2486 
  2487 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  2488 may no longer carry premises.  User-level specifications are
  2489 transformed accordingly by Thm.add_axiom/add_def.
  2490 
  2491 
  2492 *** System ***
  2493 
  2494 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  2495 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  2496 proof terms are enabled unconditionally in the new HOL-Proofs image.
  2497 
  2498 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  2499 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  2500 respectively.
  2501 
  2502 * Old lib/scripts/polyml-platform is superseded by the
  2503 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  2504 variant, even on a 64 bit machine.  The following example setting
  2505 prefers 64 bit if available:
  2506 
  2507   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  2508 
  2509 * The preliminary Isabelle/jEdit application demonstrates the emerging
  2510 Isabelle/Scala layer for advanced prover interaction and integration.
  2511 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  2512 component.
  2513 
  2514 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  2515 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  2516 similar to the default assignment of the document preparation system
  2517 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  2518 provides some operations for direct access to the font without asking
  2519 the user for manual installation.
  2520 
  2521 
  2522 
  2523 New in Isabelle2009-1 (December 2009)
  2524 -------------------------------------
  2525 
  2526 *** General ***
  2527 
  2528 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  2529 one backslash should be used, even in ML sources.
  2530 
  2531 
  2532 *** Pure ***
  2533 
  2534 * Locale interpretation propagates mixins along the locale hierarchy.
  2535 The currently only available mixins are the equations used to map
  2536 local definitions to terms of the target domain of an interpretation.
  2537 
  2538 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  2539 loc" to print all interpretations of locale "loc" in the theory.
  2540 Interpretations in proofs are not shown.
  2541 
  2542 * Thoroughly revised locales tutorial.  New section on conditional
  2543 interpretation.
  2544 
  2545 * On instantiation of classes, remaining undefined class parameters
  2546 are formally declared.  INCOMPATIBILITY.
  2547 
  2548 
  2549 *** Document preparation ***
  2550 
  2551 * New generalized style concept for printing terms: @{foo (style) ...}
  2552 instead of @{foo_style style ...}  (old form is still retained for
  2553 backward compatibility).  Styles can be also applied for
  2554 antiquotations prop, term_type and typeof.
  2555 
  2556 
  2557 *** HOL ***
  2558 
  2559 * New proof method "smt" for a combination of first-order logic with
  2560 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  2561 fixed-size bitvectors; there is also basic support for higher-order
  2562 features (esp. lambda abstractions).  It is an incomplete decision
  2563 procedure based on external SMT solvers using the oracle mechanism;
  2564 for the SMT solver Z3, this method is proof-producing.  Certificates
  2565 are provided to avoid calling the external solvers solely for
  2566 re-checking proofs.  Due to a remote SMT service there is no need for
  2567 installing SMT solvers locally.  See src/HOL/SMT.
  2568 
  2569 * New commands to load and prove verification conditions generated by
  2570 the Boogie program verifier or derived systems (e.g. the Verifying C
  2571 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  2572 
  2573 * New counterexample generator tool 'nitpick' based on the Kodkod
  2574 relational model finder.  See src/HOL/Tools/Nitpick and
  2575 src/HOL/Nitpick_Examples.
  2576 
  2577 * New commands 'code_pred' and 'values' to invoke the predicate
  2578 compiler and to enumerate values of inductive predicates.
  2579 
  2580 * A tabled implementation of the reflexive transitive closure.
  2581 
  2582 * New implementation of quickcheck uses generic code generator;
  2583 default generators are provided for all suitable HOL types, records
  2584 and datatypes.  Old quickcheck can be re-activated importing theory
  2585 Library/SML_Quickcheck.
  2586 
  2587 * New testing tool Mirabelle for automated proof tools.  Applies
  2588 several tools and tactics like sledgehammer, metis, or quickcheck, to
  2589 every proof step in a theory.  To be used in batch mode via the
  2590 "mirabelle" utility.
  2591 
  2592 * New proof method "sos" (sum of squares) for nonlinear real
  2593 arithmetic (originally due to John Harison). It requires theory
  2594 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  2595 works well in practice on quantifier-free real arithmetic with +, -,
  2596 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  2597 inequalities between polynomials.  It makes use of external
  2598 semidefinite programming solvers.  Method "sos" generates a
  2599 certificate that can be pasted into the proof thus avoiding the need
  2600 to call an external tool every time the proof is checked.  See
  2601 src/HOL/Library/Sum_Of_Squares.
  2602 
  2603 * New method "linarith" invokes existing linear arithmetic decision
  2604 procedure only.
  2605 
  2606 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  2607 
  2608 * New Sledgehammer option "Full Types" in Proof General settings menu.
  2609 Causes full type information to be output to the ATPs.  This slows
  2610 ATPs down considerably but eliminates a source of unsound "proofs"
  2611 that fail later.
  2612 
  2613 * New method "metisFT": A version of metis that uses full type
  2614 information in order to avoid failures of proof reconstruction.
  2615 
  2616 * New evaluator "approximate" approximates an real valued term using
  2617 the same method as the approximation method.
  2618 
  2619 * Method "approximate" now supports arithmetic expressions as
  2620 boundaries of intervals and implements interval splitting and Taylor
  2621 series expansion.
  2622 
  2623 * ML antiquotation @{code_datatype} inserts definition of a datatype
  2624 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  2625 
  2626 * New theory SupInf of the supremum and infimum operators for sets of
  2627 reals.
  2628 
  2629 * New theory Probability, which contains a development of measure
  2630 theory, eventually leading to Lebesgue integration and probability.
  2631 
  2632 * Extended Multivariate Analysis to include derivation and Brouwer's
  2633 fixpoint theorem.
  2634 
  2635 * Reorganization of number theory, INCOMPATIBILITY:
  2636   - new number theory development for nat and int, in theories Divides
  2637     and GCD as well as in new session Number_Theory
  2638   - some constants and facts now suffixed with _nat and _int
  2639     accordingly
  2640   - former session NumberTheory now named Old_Number_Theory, including
  2641     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  2642   - moved theory Pocklington from src/HOL/Library to
  2643     src/HOL/Old_Number_Theory
  2644 
  2645 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  2646 lcm of finite and infinite sets. It is shown that they form a complete
  2647 lattice.
  2648 
  2649 * Class semiring_div requires superclass no_zero_divisors and proof of
  2650 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  2651 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  2652 generalized to class semiring_div, subsuming former theorems
  2653 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  2654 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  2655 INCOMPATIBILITY.
  2656 
  2657 * Refinements to lattice classes and sets:
  2658   - less default intro/elim rules in locale variant, more default
  2659     intro/elim rules in class variant: more uniformity
  2660   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  2661     le_inf_iff
  2662   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  2663     sup_aci)
  2664   - renamed ACI to inf_sup_aci
  2665   - new class "boolean_algebra"
  2666   - class "complete_lattice" moved to separate theory
  2667     "Complete_Lattice"; corresponding constants (and abbreviations)
  2668     renamed and with authentic syntax:
  2669     Set.Inf ~>    Complete_Lattice.Inf
  2670     Set.Sup ~>    Complete_Lattice.Sup
  2671     Set.INFI ~>   Complete_Lattice.INFI
  2672     Set.SUPR ~>   Complete_Lattice.SUPR
  2673     Set.Inter ~>  Complete_Lattice.Inter
  2674     Set.Union ~>  Complete_Lattice.Union
  2675     Set.INTER ~>  Complete_Lattice.INTER
  2676     Set.UNION ~>  Complete_Lattice.UNION
  2677   - authentic syntax for
  2678     Set.Pow
  2679     Set.image
  2680   - mere abbreviations:
  2681     Set.empty               (for bot)
  2682     Set.UNIV                (for top)
  2683     Set.inter               (for inf, formerly Set.Int)
  2684     Set.union               (for sup, formerly Set.Un)
  2685     Complete_Lattice.Inter  (for Inf)
  2686     Complete_Lattice.Union  (for Sup)
  2687     Complete_Lattice.INTER  (for INFI)
  2688     Complete_Lattice.UNION  (for SUPR)
  2689   - object-logic definitions as far as appropriate
  2690 
  2691 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  2692 Un_subset_iff are explicitly deleted as default simp rules; then also
  2693 their lattice counterparts le_inf_iff and le_sup_iff have to be
  2694 deleted to achieve the desired effect.
  2695 
  2696 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  2697 rules by default any longer; the same applies to min_max.inf_absorb1
  2698 etc.  INCOMPATIBILITY.
  2699 
  2700 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  2701 pred_set_conv by default.  INCOMPATIBILITY.
  2702 
  2703 * Power operations on relations and functions are now one dedicated
  2704 constant "compow" with infix syntax "^^".  Power operation on
  2705 multiplicative monoids retains syntax "^" and is now defined generic
  2706 in class power.  INCOMPATIBILITY.
  2707 
  2708 * Relation composition "R O S" now has a more standard argument order:
  2709 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  2710 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  2711 break, since the O_assoc rule was not rewritten like this.  Fix using
  2712 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  2713 
  2714 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  2715 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  2716 INCOMPATIBILITY.
  2717 
  2718 * Most rules produced by inductive and datatype package have mandatory
  2719 prefixes.  INCOMPATIBILITY.
  2720 
  2721 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  2722 the attribute of the same name.  Each of the theorems in the list
  2723 DERIV_intros assumes composition with an additional function and
  2724 matches a variable to the derivative, which has to be solved by the
  2725 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  2726 of most elementary terms.  Former Maclauren.DERIV_tac and
  2727 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  2728 INCOMPATIBILITY.
  2729 
  2730 * Code generator attributes follow the usual underscore convention:
  2731     code_unfold     replaces    code unfold
  2732     code_post       replaces    code post
  2733     etc.
  2734   INCOMPATIBILITY.
  2735 
  2736 * Renamed methods:
  2737     sizechange -> size_change
  2738     induct_scheme -> induction_schema
  2739   INCOMPATIBILITY.
  2740 
  2741 * Discontinued abbreviation "arbitrary" of constant "undefined".
  2742 INCOMPATIBILITY, use "undefined" directly.
  2743 
  2744 * Renamed theorems:
  2745     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  2746     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  2747     Suc_plus1 -> Suc_eq_plus1
  2748     *anti_sym -> *antisym*
  2749     vector_less_eq_def -> vector_le_def
  2750   INCOMPATIBILITY.
  2751 
  2752 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  2753 INCOMPATIBILITY.
  2754 
  2755 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  2756 INCOMPATIBILITY.
  2757 
  2758 
  2759 *** HOLCF ***
  2760 
  2761 * Theory Representable defines a class "rep" of domains that are
  2762 representable (via an ep-pair) in the universal domain type "udom".
  2763 Instances are provided for all type constructors defined in HOLCF.
  2764 
  2765 * The 'new_domain' command is a purely definitional version of the
  2766 domain package, for representable domains.  Syntax is identical to the
  2767 old domain package.  The 'new_domain' package also supports indirect
  2768 recursion using previously-defined type constructors.  See
  2769 src/HOLCF/ex/New_Domain.thy for examples.
  2770 
  2771 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  2772 on the left-hand side of an equation, and then performs
  2773 simplification.  Rewriting is done using rules declared with the
  2774 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  2775 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  2776 
  2777 * The pattern-match compiler in 'fixrec' can now handle constructors
  2778 with HOL function types.  Pattern-match combinators for the Pair
  2779 constructor are pre-configured.
  2780 
  2781 * The 'fixrec' package now produces better fixed-point induction rules
  2782 for mutually-recursive definitions:  Induction rules have conclusions
  2783 of the form "P foo bar" instead of "P <foo, bar>".
  2784 
  2785 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  2786 been renamed to "below".  The name "below" now replaces "less" in many
  2787 theorem names.  (Legacy theorem names using "less" are still supported
  2788 as well.)
  2789 
  2790 * The 'fixrec' package now supports "bottom patterns".  Bottom
  2791 patterns can be used to generate strictness rules, or to make
  2792 functions more strict (much like the bang-patterns supported by the
  2793 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  2794 examples.
  2795 
  2796 
  2797 *** ML ***
  2798 
  2799 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  2800 errors and run-time exceptions, including detailed source positions.
  2801 
  2802 * Structure Name_Space (formerly NameSpace) now manages uniquely
  2803 identified entries, with some additional information such as source
  2804 position, logical grouping etc.
  2805 
  2806 * Theory and context data is now introduced by the simplified and
  2807 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  2808 to be pure, but the old TheoryDataFun for mutable data (with explicit
  2809 copy operation) is still available for some time.
  2810 
  2811 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2812 provides a high-level programming interface to synchronized state
  2813 variables with atomic update.  This works via pure function
  2814 application within a critical section -- its runtime should be as
  2815 short as possible; beware of deadlocks if critical code is nested,
  2816 either directly or indirectly via other synchronized variables!
  2817 
  2818 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2819 wraps raw ML references, explicitly indicating their non-thread-safe
  2820 behaviour.  The Isar toplevel keeps this structure open, to
  2821 accommodate Proof General as well as quick and dirty interactive
  2822 experiments with references.
  2823 
  2824 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2825 parallel tactical reasoning.
  2826 
  2827 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2828 are similar to SUBPROOF, but are slightly more flexible: only the
  2829 specified parts of the subgoal are imported into the context, and the
  2830 body tactic may introduce new subgoals and schematic variables.
  2831 
  2832 * Old tactical METAHYPS, which does not observe the proof context, has
  2833 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2834 or Subgoal.FOCUS etc.
  2835 
  2836 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2837 functors have their own ML name space there is no point to mark them
  2838 separately.)  Minor INCOMPATIBILITY.
  2839 
  2840 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2841 
  2842 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2843 INCOMPATIBILITY.
  2844 
  2845 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2846 mode, which avoids critical setmp.
  2847 
  2848 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2849 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2850 Attrib/Method.setup introduced in Isabelle2009.
  2851 
  2852 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2853 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2854 last resort.  INCOMPATIBILITY.
  2855 
  2856 * Display.pretty_thm now requires a proper context (cf. former
  2857 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2858 or even Display.pretty_thm_without_context as last resort.
  2859 INCOMPATIBILITY.
  2860 
  2861 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2862 Syntax.pretty_typ/term directly, preferably with proper context
  2863 instead of global theory.
  2864 
  2865 
  2866 *** System ***
  2867 
  2868 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2869 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2870 usedir option -q.
  2871 
  2872 * Support for additional "Isabelle components" via etc/components, see
  2873 also the system manual.
  2874 
  2875 * The isabelle makeall tool now operates on all components with
  2876 IsaMakefile, not just hardwired "logics".
  2877 
  2878 * Removed "compress" option from isabelle-process and isabelle usedir;
  2879 this is always enabled.
  2880 
  2881 * Discontinued support for Poly/ML 4.x versions.
  2882 
  2883 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2884 on a given logic image.  This requires the lighttpd webserver and is
  2885 currently supported on Linux only.
  2886 
  2887 
  2888 
  2889 New in Isabelle2009 (April 2009)
  2890 --------------------------------
  2891 
  2892 *** General ***
  2893 
  2894 * Simplified main Isabelle executables, with less surprises on
  2895 case-insensitive file-systems (such as Mac OS).
  2896 
  2897   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2898     "isatool."
  2899 
  2900   - The former "isabelle" alias for "isabelle-process" has been
  2901     removed (should rarely occur to regular users).
  2902 
  2903   - The former "isabelle-interface" and its alias "Isabelle" have been
  2904     removed (interfaces are now regular Isabelle tools).
  2905 
  2906 Within scripts and make files, the Isabelle environment variables
  2907 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2908 respectively.  (The latter are still available as legacy feature.)
  2909 
  2910 The old isabelle-interface wrapper could react in confusing ways if
  2911 the interface was uninstalled or changed otherwise.  Individual
  2912 interface tool configuration is now more explicit, see also the
  2913 Isabelle system manual.  In particular, Proof General is now available
  2914 via "isabelle emacs".
  2915 
  2916 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2917 purge installed copies of Isabelle executables and re-run "isabelle
  2918 install -p ...", or use symlinks.
  2919 
  2920 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2921 old ~/isabelle, which was slightly non-standard and apt to cause
  2922 surprises on case-insensitive file-systems (such as Mac OS).
  2923 
  2924 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2925 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2926 care is required when using older releases of Isabelle.  Note that
  2927 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2928 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2929 
  2930 * Proofs of fully specified statements are run in parallel on
  2931 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2932 a regular 4-core machine, if the initial heap space is made reasonably
  2933 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2934 
  2935 * The main reference manuals ("isar-ref", "implementation", and
  2936 "system") have been updated and extended.  Formally checked references
  2937 as hyperlinks are now available uniformly.
  2938 
  2939 
  2940 *** Pure ***
  2941 
  2942 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2943 respects.  The most important changes are listed below.  See the
  2944 Tutorial on Locales ("locales" manual) for details.
  2945 
  2946 - In locale expressions, instantiation replaces renaming.  Parameters
  2947 must be declared in a for clause.  To aid compatibility with previous
  2948 parameter inheritance, in locale declarations, parameters that are not
  2949 'touched' (instantiation position "_" or omitted) are implicitly added
  2950 with their syntax at the beginning of the for clause.
  2951 
  2952 - Syntax from abbreviations and definitions in locales is available in
  2953 locale expressions and context elements.  The latter is particularly
  2954 useful in locale declarations.
  2955 
  2956 - More flexible mechanisms to qualify names generated by locale
  2957 expressions.  Qualifiers (prefixes) may be specified in locale
  2958 expressions, and can be marked as mandatory (syntax: "name!:") or
  2959 optional (syntax "name?:").  The default depends for plain "name:"
  2960 depends on the situation where a locale expression is used: in
  2961 commands 'locale' and 'sublocale' prefixes are optional, in
  2962 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2963 implicit qualifiers derived from the parameter names of a locale are
  2964 no longer generated.
  2965 
  2966 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2967 instantiation clause in "interpretation" and "interpret" (square
  2968 brackets) is no longer available.  Use locale expressions.
  2969 
  2970 - When converting proof scripts, mandatory qualifiers in
  2971 'interpretation' and 'interpret' should be retained by default, even
  2972 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2973 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2974 in locale expressions range over a single locale instance only.
  2975 
  2976 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2977 In existing theorem specifications replace the includes element by the
  2978 respective context elements of the included locale, omitting those
  2979 that are already present in the theorem specification.  Multiple
  2980 assume elements of a locale should be replaced by a single one
  2981 involving the locale predicate.  In the proof body, declarations (most
  2982 notably theorems) may be regained by interpreting the respective
  2983 locales in the proof context as required (command "interpret").
  2984 
  2985 If using "includes" in replacement of a target solely because the
  2986 parameter types in the theorem are not as general as in the target,
  2987 consider declaring a new locale with additional type constraints on
  2988 the parameters (context element "constrains").
  2989 
  2990 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2991 
  2992 - Locale interpretation commands no longer attempt to simplify goal.
  2993 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2994 methods intro_locales and unfold_locales to clarify.
  2995 
  2996 - Locale interpretation commands no longer accept interpretation
  2997 attributes.  INCOMPATIBILITY.
  2998 
  2999 * Class declaration: so-called "base sort" must not be given in import
  3000 list any longer, but is inferred from the specification.  Particularly
  3001 in HOL, write
  3002 
  3003     class foo = ...
  3004 
  3005 instead of
  3006 
  3007     class foo = type + ...
  3008 
  3009 * Class target: global versions of theorems stemming do not carry a
  3010 parameter prefix any longer.  INCOMPATIBILITY.
  3011 
  3012 * Class 'instance' command no longer accepts attached definitions.
  3013 INCOMPATIBILITY, use proper 'instantiation' target instead.
  3014 
  3015 * Recovered hiding of consts, which was accidentally broken in
  3016 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  3017 makes c inaccessible; consider using ``hide (open) const c'' instead.
  3018 
  3019 * Slightly more coherent Pure syntax, with updated documentation in
  3020 isar-ref manual.  Removed locales meta_term_syntax and
  3021 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  3022 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  3023 directly in regular applications.
  3024 
  3025 * There is a new syntactic category "float_const" for signed decimal
  3026 fractions (e.g. 123.45 or -123.45).
  3027 
  3028 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  3029 interface with 'setup' command instead.
  3030 
  3031 * Command 'local_setup' is similar to 'setup', but operates on a local
  3032 theory context.
  3033 
  3034 * The 'axiomatization' command now only works within a global theory
  3035 context.  INCOMPATIBILITY.
  3036 
  3037 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  3038 hypotheses.  Sorts required in the course of reasoning need to be
  3039 covered by the constraints in the initial statement, completed by the
  3040 type instance information of the background theory.  Non-trivial sort
  3041 hypotheses, which rarely occur in practice, may be specified via
  3042 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  3043 
  3044   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  3045 
  3046 The result contains an implicit sort hypotheses as before --
  3047 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  3048 normalization.
  3049 
  3050 * Generalized Isar history, with support for linear undo, direct state
  3051 addressing etc.
  3052 
  3053 * Changed defaults for unify configuration options:
  3054 
  3055   unify_trace_bound = 50 (formerly 25)
  3056   unify_search_bound = 60 (formerly 30)
  3057 
  3058 * Different bookkeeping for code equations (INCOMPATIBILITY):
  3059 
  3060   a) On theory merge, the last set of code equations for a particular
  3061      constant is taken (in accordance with the policy applied by other
  3062      parts of the code generator framework).
  3063 
  3064   b) Code equations stemming from explicit declarations (e.g. code
  3065      attribute) gain priority over default code equations stemming
  3066      from definition, primrec, fun etc.
  3067 
  3068 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  3069 
  3070 * Unified theorem tables for both code generators.  Thus [code
  3071 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  3072 
  3073 * Command 'find_consts' searches for constants based on type and name
  3074 patterns, e.g.
  3075 
  3076     find_consts "_ => bool"
  3077 
  3078 By default, matching is against subtypes, but it may be restricted to
  3079 the whole type.  Searching by name is possible.  Multiple queries are
  3080 conjunctive and queries may be negated by prefixing them with a
  3081 hyphen:
  3082 
  3083     find_consts strict: "_ => bool" name: "Int" -"int => int"
  3084 
  3085 * New 'find_theorems' criterion "solves" matches theorems that
  3086 directly solve the current goal (modulo higher-order unification).
  3087 
  3088 * Auto solve feature for main theorem statements: whenever a new goal
  3089 is stated, "find_theorems solves" is called; any theorems that could
  3090 solve the lemma directly are listed as part of the goal state.
  3091 Cf. associated options in Proof General Isabelle settings menu,
  3092 enabled by default, with reasonable timeout for pathological cases of
  3093 higher-order unification.
  3094 
  3095 
  3096 *** Document preparation ***
  3097 
  3098 * Antiquotation @{lemma} now imitates a regular terminal proof,
  3099 demanding keyword 'by' and supporting the full method expression
  3100 syntax just like the Isar command 'by'.
  3101 
  3102 
  3103 *** HOL ***
  3104 
  3105 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  3106 points Main and Complex_Main remain as before.
  3107 
  3108 * Logic image HOL-Plain provides a minimal HOL with the most important
  3109 tools available (inductive, datatype, primrec, ...).  This facilitates
  3110 experimentation and tool development.  Note that user applications
  3111 (and library theories) should never refer to anything below theory
  3112 Main, as before.
  3113 
  3114 * Logic image HOL-Main stops at theory Main, and thus facilitates
  3115 experimentation due to shorter build times.
  3116 
  3117 * Logic image HOL-NSA contains theories of nonstandard analysis which
  3118 were previously part of former HOL-Complex.  Entry point Hyperreal
  3119 remains valid, but theories formerly using Complex_Main should now use
  3120 new entry point Hypercomplex.
  3121 
  3122 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  3123 Posix processes.  Avoids potentially expensive forking of the ML
  3124 process.  New thread-based implementation also works on non-Unix
  3125 platforms (Cygwin).  Provers are no longer hardwired, but defined
  3126 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  3127 commands are covered in the isar-ref manual.
  3128 
  3129 * Wrapper scripts for remote SystemOnTPTP service allows to use
  3130 sledgehammer without local ATP installation (Vampire etc.). Other
  3131 provers may be included via suitable ML wrappers, see also
  3132 src/HOL/ATP_Linkup.thy.
  3133 
  3134 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  3135 menu.
  3136 
  3137 * The metis method no longer fails because the theorem is too trivial
  3138 (contains the empty clause).
  3139 
  3140 * The metis method now fails in the usual manner, rather than raising
  3141 an exception, if it determines that it cannot prove the theorem.
  3142 
  3143 * Method "coherent" implements a prover for coherent logic (see also
  3144 src/Tools/coherent.ML).
  3145 
  3146 * Constants "undefined" and "default" replace "arbitrary".  Usually
  3147 "undefined" is the right choice to replace "arbitrary", though
  3148 logically there is no difference.  INCOMPATIBILITY.
  3149 
  3150 * Command "value" now integrates different evaluation mechanisms.  The
  3151 result of the first successful evaluation mechanism is printed.  In
  3152 square brackets a particular named evaluation mechanisms may be
  3153 specified (currently, [SML], [code] or [nbe]).  See further
  3154 src/HOL/ex/Eval_Examples.thy.
  3155 
  3156 * Normalization by evaluation now allows non-leftlinear equations.
  3157 Declare with attribute [code nbe].
  3158 
  3159 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  3160 as the structured Isar versions "cases" and "induct", cf. the
  3161 corresponding "cases" and "induct" attributes.  Mutual induction rules
  3162 are now presented as a list of individual projections
  3163 (e.g. foo_bar.inducts for types foo and bar); the old format with
  3164 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  3165 rare situations a different rule is selected --- notably nested tuple
  3166 elimination instead of former prod.exhaust: use explicit (case_tac t
  3167 rule: prod.exhaust) here.
  3168 
  3169 * Attributes "cases", "induct", "coinduct" support "del" option.
  3170 
  3171 * Removed fact "case_split_thm", which duplicates "case_split".
  3172 
  3173 * The option datatype has been moved to a new theory Option.  Renamed
  3174 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  3175 
  3176 * New predicate "strict_mono" classifies strict functions on partial
  3177 orders.  With strict functions on linear orders, reasoning about
  3178 (in)equalities is facilitated by theorems "strict_mono_eq",
  3179 "strict_mono_less_eq" and "strict_mono_less".
  3180 
  3181 * Some set operations are now proper qualified constants with
  3182 authentic syntax.  INCOMPATIBILITY:
  3183 
  3184     op Int ~>   Set.Int
  3185     op Un ~>    Set.Un
  3186     INTER ~>    Set.INTER
  3187     UNION ~>    Set.UNION
  3188     Inter ~>    Set.Inter
  3189     Union ~>    Set.Union
  3190     {} ~>       Set.empty
  3191     UNIV ~>     Set.UNIV
  3192 
  3193 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  3194 theory Set.
  3195 
  3196 * Auxiliary class "itself" has disappeared -- classes without any
  3197 parameter are treated as expected by the 'class' command.
  3198 
  3199 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  3200 
  3201 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  3202 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  3203 
  3204 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  3205 method "approximation".  It proves formulas on real values by using
  3206 interval arithmetic.  In the formulas are also the transcendental
  3207 functions sin, cos, tan, atan, ln, exp and the constant pi are
  3208 allowed. For examples see
  3209 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  3210 
  3211 * Theory "Reflection" now resides in HOL/Library.
  3212 
  3213 * Entry point to Word library now simply named "Word".
  3214 INCOMPATIBILITY.
  3215 
  3216 * Made source layout more coherent with logical distribution
  3217 structure:
  3218 
  3219     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  3220     src/HOL/Library/Code_Message.thy ~> src/HOL/
  3221     src/HOL/Library/GCD.thy ~> src/HOL/
  3222     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  3223     src/HOL/Library/Parity.thy ~> src/HOL/
  3224     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  3225     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  3226     src/HOL/Real/Lubs.thy ~> src/HOL/
  3227     src/HOL/Real/PReal.thy ~> src/HOL/
  3228     src/HOL/Real/Rational.thy ~> src/HOL/
  3229     src/HOL/Real/RComplete.thy ~> src/HOL/
  3230     src/HOL/Real/RealDef.thy ~> src/HOL/
  3231     src/HOL/Real/RealPow.thy ~> src/HOL/
  3232     src/HOL/Real/Real.thy ~> src/HOL/
  3233     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  3234     src/HOL/Complex/Complex.thy ~> src/HOL/
  3235     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  3236     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  3237     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  3238     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  3239     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  3240     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  3241     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  3242     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  3243     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  3244     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  3245     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  3246     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  3247     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  3248     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  3249     src/HOL/Real/Float ~> src/HOL/Library/
  3250     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  3251     src/HOL/Real/RealVector.thy ~> src/HOL/
  3252 
  3253     src/HOL/arith_data.ML ~> src/HOL/Tools
  3254     src/HOL/hologic.ML ~> src/HOL/Tools
  3255     src/HOL/simpdata.ML ~> src/HOL/Tools
  3256     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  3257     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  3258     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  3259     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  3260     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  3261     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  3262     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  3263 
  3264     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  3265     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3266     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3267     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3268     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3269     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3270 
  3271 * If methods "eval" and "evaluation" encounter a structured proof
  3272 state with !!/==>, only the conclusion is evaluated to True (if
  3273 possible), avoiding strange error messages.
  3274 
  3275 * Method "sizechange" automates termination proofs using (a
  3276 modification of) the size-change principle.  Requires SAT solver.  See
  3277 src/HOL/ex/Termination.thy for examples.
  3278 
  3279 * Simplifier: simproc for let expressions now unfolds if bound
  3280 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3281 
  3282 * Method "arith": Linear arithmetic now ignores all inequalities when
  3283 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3284 
  3285 * New attribute "arith" for facts that should always be used
  3286 automatically by arithmetic. It is intended to be used locally in
  3287 proofs, e.g.
  3288 
  3289   assumes [arith]: "x > 0"
  3290 
  3291 Global usage is discouraged because of possible performance impact.
  3292 
  3293 * New classes "top" and "bot" with corresponding operations "top" and
  3294 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3295 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3296 
  3297 * Changed definition lemma "less_fun_def" in order to provide an
  3298 instance for preorders on functions; use lemma "less_le" instead.
  3299 INCOMPATIBILITY.
  3300 
  3301 * Theory Orderings: class "wellorder" moved here, with explicit
  3302 induction rule "less_induct" as assumption.  For instantiation of
  3303 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3304 INCOMPATIBILITY.
  3305 
  3306 * Theory Orderings: added class "preorder" as superclass of "order".
  3307 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3308 etc. slightly changed.  Some theorems named order_class.* now named
  3309 preorder_class.*.
  3310 
  3311 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3312 "diag" to "Id_on".
  3313 
  3314 * Theory Finite_Set: added a new fold combinator of type
  3315 
  3316   ('a => 'b => 'b) => 'b => 'a set => 'b
  3317 
  3318 Occasionally this is more convenient than the old fold combinator
  3319 which is now defined in terms of the new one and renamed to
  3320 fold_image.
  3321 
  3322 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3323 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3324 extended with further lemmas!).  At the moment both still exist but
  3325 the former will disappear at some point.
  3326 
  3327 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3328 class recpower.  Type-specific simp rules for various recpower types
  3329 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3330 
  3331 rat_power_0    -> power_0
  3332 rat_power_Suc  -> power_Suc
  3333 realpow_0      -> power_0
  3334 realpow_Suc    -> power_Suc
  3335 complexpow_0   -> power_0
  3336 complexpow_Suc -> power_Suc
  3337 power_poly_0   -> power_0
  3338 power_poly_Suc -> power_Suc
  3339 
  3340 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3341 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3342 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3343 of lemmas from Divides has been generalized from nat to class
  3344 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3345 renames resulting from duplicate elimination:
  3346 
  3347     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3348     zero_dvd_iff ~>         dvd_0_left_iff
  3349     dvd_0 ~>                dvd_0_right
  3350     DIVISION_BY_ZERO_DIV ~> div_by_0
  3351     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3352     mult_div ~>             div_mult_self2_is_id
  3353     mult_mod ~>             mod_mult_self2_is_0
  3354 
  3355 * Theory IntDiv: removed many lemmas that are instances of class-based
  3356 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3357 rename old lemmas as follows:
  3358 
  3359 dvd_diff               -> nat_dvd_diff
  3360 dvd_zminus_iff         -> dvd_minus_iff
  3361 mod_add1_eq            -> mod_add_eq
  3362 mod_mult1_eq           -> mod_mult_right_eq
  3363 mod_mult1_eq'          -> mod_mult_left_eq
  3364 mod_mult_distrib_mod   -> mod_mult_eq
  3365 nat_mod_add_left_eq    -> mod_add_left_eq
  3366 nat_mod_add_right_eq   -> mod_add_right_eq
  3367 nat_mod_div_trivial    -> mod_div_trivial
  3368 nat_mod_mod_trivial    -> mod_mod_trivial
  3369 zdiv_zadd_self1        -> div_add_self1
  3370 zdiv_zadd_self2        -> div_add_self2
  3371 zdiv_zmult_self1       -> div_mult_self2_is_id
  3372 zdiv_zmult_self2       -> div_mult_self1_is_id
  3373 zdvd_triv_left         -> dvd_triv_left
  3374 zdvd_triv_right        -> dvd_triv_right
  3375 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3376 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3377 zmod_zadd_left_eq      -> mod_add_left_eq
  3378 zmod_zadd_right_eq     -> mod_add_right_eq
  3379 zmod_zadd_self1        -> mod_add_self1
  3380 zmod_zadd_self2        -> mod_add_self2
  3381 zmod_zadd1_eq          -> mod_add_eq
  3382 zmod_zdiff1_eq         -> mod_diff_eq
  3383 zmod_zdvd_zmod         -> mod_mod_cancel
  3384 zmod_zmod_cancel       -> mod_mod_cancel
  3385 zmod_zmult_self1       -> mod_mult_self2_is_0
  3386 zmod_zmult_self2       -> mod_mult_self1_is_0
  3387 zmod_1                 -> mod_by_1
  3388 zdiv_1                 -> div_by_1
  3389 zdvd_abs1              -> abs_dvd_iff
  3390 zdvd_abs2              -> dvd_abs_iff
  3391 zdvd_refl              -> dvd_refl
  3392 zdvd_trans             -> dvd_trans
  3393 zdvd_zadd              -> dvd_add
  3394 zdvd_zdiff             -> dvd_diff
  3395 zdvd_zminus_iff        -> dvd_minus_iff
  3396 zdvd_zminus2_iff       -> minus_dvd_iff
  3397 zdvd_zmultD            -> dvd_mult_right
  3398 zdvd_zmultD2           -> dvd_mult_left
  3399 zdvd_zmult_mono        -> mult_dvd_mono
  3400 zdvd_0_right           -> dvd_0_right
  3401 zdvd_0_left            -> dvd_0_left_iff
  3402 zdvd_1_left            -> one_dvd
  3403 zminus_dvd_iff         -> minus_dvd_iff
  3404 
  3405 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3406 
  3407 * The real numbers offer decimal input syntax: 12.34 is translated
  3408 into 1234/10^2. This translation is not reversed upon output.
  3409 
  3410 * Theory Library/Polynomial defines an abstract type 'a poly of
  3411 univariate polynomials with coefficients of type 'a.  In addition to
  3412 the standard ring operations, it also supports div and mod.  Code
  3413 generation is also supported, using list-style constructors.
  3414 
  3415 * Theory Library/Inner_Product defines a class of real_inner for real
  3416 inner product spaces, with an overloaded operation inner :: 'a => 'a
  3417 => real.  Class real_inner is a subclass of real_normed_vector from
  3418 theory RealVector.
  3419 
  3420 * Theory Library/Product_Vector provides instances for the product
  3421 type 'a * 'b of several classes from RealVector and Inner_Product.
  3422 Definitions of addition, subtraction, scalar multiplication, norms,
  3423 and inner products are included.
  3424 
  3425 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  3426 addition to the field operations, numerals and case syntax are also
  3427 supported.
  3428 
  3429 * Theory Library/Diagonalize provides constructive version of Cantor's
  3430 first diagonalization argument.
  3431 
  3432 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  3433 zlcm (for int); carried together from various gcd/lcm developements in
  3434 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  3435 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  3436 may recover tupled syntax as follows:
  3437 
  3438     hide (open) const gcd
  3439     abbreviation gcd where
  3440       "gcd == (%(a, b). GCD.gcd a b)"
  3441     notation (output)
  3442       GCD.gcd ("gcd '(_, _')")
  3443 
  3444 The same works for lcm, zgcd, zlcm.
  3445 
  3446 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  3447 instantiations for algebraic structures.  Removed some duplicate
  3448 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  3449 
  3450 * ML antiquotation @{code} takes a constant as argument and generates
  3451 corresponding code in background and inserts name of the corresponding
  3452 resulting ML value/function/datatype constructor binding in place.
  3453 All occurrences of @{code} with a single ML block are generated
  3454 simultaneously.  Provides a generic and safe interface for
  3455 instrumentalizing code generation.  See
  3456 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  3457 In future you ought to refrain from ad-hoc compiling generated SML
  3458 code on the ML toplevel.  Note that (for technical reasons) @{code}
  3459 cannot refer to constants for which user-defined serializations are
  3460 set.  Refer to the corresponding ML counterpart directly in that
  3461 cases.
  3462 
  3463 * Command 'rep_datatype': instead of theorem names the command now
  3464 takes a list of terms denoting the constructors of the type to be
  3465 represented as datatype.  The characteristic theorems have to be
  3466 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  3467 have disappeared in favour of existing ones:
  3468 
  3469     unit_induct                 ~> unit.induct
  3470     prod_induct                 ~> prod.induct
  3471     sum_induct                  ~> sum.induct
  3472     Suc_Suc_eq                  ~> nat.inject
  3473     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  3474 
  3475 
  3476 *** HOL-Algebra ***
  3477 
  3478 * New locales for orders and lattices where the equivalence relation
  3479 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  3480 locales use a record structure with field eq for the equivalence.
  3481 
  3482 * New theory of factorial domains.
  3483 
  3484 * Units_l_inv and Units_r_inv are now simp rules by default.
  3485 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  3486 and/or r_inv will now also require deletion of these lemmas.
  3487 
  3488 * Renamed the following theorems, INCOMPATIBILITY:
  3489 
  3490 UpperD ~> Upper_memD
  3491 LowerD ~> Lower_memD
  3492 least_carrier ~> least_closed
  3493 greatest_carrier ~> greatest_closed
  3494 greatest_Lower_above ~> greatest_Lower_below
  3495 one_zero ~> carrier_one_zero
  3496 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  3497 
  3498 
  3499 *** HOL-Nominal ***
  3500 
  3501 * Nominal datatypes can now contain type-variables.
  3502 
  3503 * Commands 'nominal_inductive' and 'equivariance' work with local
  3504 theory targets.
  3505 
  3506 * Nominal primrec can now works with local theory targets and its
  3507 specification syntax now conforms to the general format as seen in
  3508 'inductive' etc.
  3509 
  3510 * Method "perm_simp" honours the standard simplifier attributes
  3511 (no_asm), (no_asm_use) etc.
  3512 
  3513 * The new predicate #* is defined like freshness, except that on the
  3514 left hand side can be a set or list of atoms.
  3515 
  3516 * Experimental command 'nominal_inductive2' derives strong induction
  3517 principles for inductive definitions.  In contrast to
  3518 'nominal_inductive', which can only deal with a fixed number of
  3519 binders, it can deal with arbitrary expressions standing for sets of
  3520 atoms to be avoided.  The only inductive definition we have at the
  3521 moment that needs this generalisation is the typing rule for Lets in
  3522 the algorithm W:
  3523 
  3524  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  3525  -----------------------------------------------------------------
  3526          Gamma |- Let x be t1 in t2 : T2
  3527 
  3528 In this rule one wants to avoid all the binders that are introduced by
  3529 "close Gamma T1".  We are looking for other examples where this
  3530 feature might be useful.  Please let us know.
  3531 
  3532 
  3533 *** HOLCF ***
  3534 
  3535 * Reimplemented the simplification procedure for proving continuity
  3536 subgoals.  The new simproc is extensible; users can declare additional
  3537 continuity introduction rules with the attribute [cont2cont].
  3538 
  3539 * The continuity simproc now uses a different introduction rule for
  3540 solving continuity subgoals on terms with lambda abstractions.  In
  3541 some rare cases the new simproc may fail to solve subgoals that the
  3542 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  3543 Potential INCOMPATIBILITY.
  3544 
  3545 * Command 'fixrec': specification syntax now conforms to the general
  3546 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  3547 examples.  INCOMPATIBILITY.
  3548 
  3549 
  3550 *** ZF ***
  3551 
  3552 * Proof of Zorn's Lemma for partial orders.
  3553 
  3554 
  3555 *** ML ***
  3556 
  3557 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  3558 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  3559 depends on multithreading, so timouts will not work before Poly/ML
  3560 5.2.1!
  3561 
  3562 * High-level support for concurrent ML programming, see
  3563 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  3564 particularly convenient to organize independent functional
  3565 computations.  The concept of "synchronized variables" provides a
  3566 higher-order interface for components with shared state, avoiding the
  3567 delicate details of mutexes and condition variables.  (Requires
  3568 Poly/ML 5.2.1 or later.)
  3569 
  3570 * ML bindings produced via Isar commands are stored within the Isar
  3571 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  3572 become thread-safe and work with undo as expected (concerning
  3573 top-level bindings, not side-effects on global references).
  3574 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  3575 compiler at runtime; really global bindings need to be given outside a
  3576 theory.  (Requires Poly/ML 5.2 or later.)
  3577 
  3578 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  3579 context.  Top-level ML bindings are stored within the proof context in
  3580 a purely sequential fashion, disregarding the nested proof structure.
  3581 ML bindings introduced by 'ML_prf' are discarded at the end of the
  3582 proof.  (Requires Poly/ML 5.2 or later.)
  3583 
  3584 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  3585 and Method.setup, as well as Isar commands 'attribute_setup' and
  3586 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  3587 existing code accordingly, or use plain 'setup' together with old
  3588 Method.add_method.
  3589 
  3590 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  3591 to 'a -> thm, while results are always tagged with an authentic oracle
  3592 name.  The Isar command 'oracle' is now polymorphic, no argument type
  3593 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  3594 accordingly.  Note that extra performance may be gained by producing
  3595 the cterm carefully, avoiding slow Thm.cterm_of.
  3596 
  3597 * Simplified interface for defining document antiquotations via
  3598 ThyOutput.antiquotation, ThyOutput.output, and optionally
  3599 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  3600 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  3601 examples.
  3602 
  3603 * More systematic treatment of long names, abstract name bindings, and
  3604 name space operations.  Basic operations on qualified names have been
  3605 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  3606 Long_Name.append.  Old type bstring has been mostly replaced by
  3607 abstract type binding (see structure Binding), which supports precise
  3608 qualification by packages and local theory targets, as well as proper
  3609 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  3610 bstring values into Binding.name, or better pass through abstract
  3611 bindings everywhere.  See further src/Pure/General/long_name.ML,
  3612 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  3613 
  3614 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  3615 LocalTheory.note etc.) now refer to the *full* internal name, not the
  3616 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  3617 
  3618 * Disposed old type and term read functions (Sign.read_def_typ,
  3619 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  3620 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  3621 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  3622 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  3623 resort for legacy applications.
  3624 
  3625 * Disposed old declarations, tactics, tactic combinators that refer to
  3626 the simpset or claset of an implicit theory (such as Addsimps,
  3627 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  3628 embedded ML text, or local_simpset_of with a proper context passed as
  3629 explicit runtime argument.
  3630 
  3631 * Rules and tactics that read instantiations (read_instantiate,
  3632 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  3633 context, which is required for parsing and type-checking.  Moreover,
  3634 the variables are specified as plain indexnames, not string encodings
  3635 thereof.  INCOMPATIBILITY.
  3636 
  3637 * Generic Toplevel.add_hook interface allows to analyze the result of
  3638 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  3639 for theorem dependency output of transactions resulting in a new
  3640 theory state.
  3641 
  3642 * ML antiquotations: block-structured compilation context indicated by
  3643 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  3644 
  3645   @{binding name}                         - basic name binding
  3646   @{let ?pat = term}                      - term abbreviation (HO matching)
  3647   @{note name = fact}                     - fact abbreviation
  3648   @{thm fact}                             - singleton fact (with attributes)
  3649   @{thms fact}                            - general fact (with attributes)
  3650   @{lemma prop by method}                 - singleton goal
  3651   @{lemma prop by meth1 meth2}            - singleton goal
  3652   @{lemma prop1 ... propN by method}      - general goal
  3653   @{lemma prop1 ... propN by meth1 meth2} - general goal
  3654   @{lemma (open) ...}                     - open derivation
  3655 
  3656 
  3657 *** System ***
  3658 
  3659 * The Isabelle "emacs" tool provides a specific interface to invoke
  3660 Proof General / Emacs, with more explicit failure if that is not
  3661 installed (the old isabelle-interface script silently falls back on
  3662 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  3663 installation location of the Proof General distribution.
  3664 
  3665 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  3666 the Isabelle process into a JVM/Scala application.  See
  3667 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  3668 process wrapper has been discontinued.)
  3669 
  3670 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  3671 
  3672 * Various status messages (with exact source position information) are
  3673 emitted, if proper markup print mode is enabled.  This allows
  3674 user-interface components to provide detailed feedback on internal
  3675 prover operations.
  3676 
  3677 
  3678 
  3679 New in Isabelle2008 (June 2008)
  3680 -------------------------------
  3681 
  3682 *** General ***
  3683 
  3684 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  3685 and updated, with formally checked references as hyperlinks.
  3686 
  3687 * Theory loader: use_thy (and similar operations) no longer set the
  3688 implicit ML context, which was occasionally hard to predict and in
  3689 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  3690 provides a proper context already.
  3691 
  3692 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3693 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  3694 'use' within a theory file will do the job.
  3695 
  3696 * Name space merge now observes canonical order, i.e. the second space
  3697 is inserted into the first one, while existing entries in the first
  3698 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  3699 swap theory imports.
  3700 
  3701 * Syntax: symbol \<chi> is now considered a letter.  Potential
  3702 INCOMPATIBILITY in identifier syntax etc.
  3703 
  3704 * Outer syntax: string tokens no longer admit escaped white space,
  3705 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  3706 white space without escapes.
  3707 
  3708 * Outer syntax: string tokens may contain arbitrary character codes
  3709 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  3710 "foo_bar".
  3711 
  3712 
  3713 *** Pure ***
  3714 
  3715 * Context-dependent token translations.  Default setup reverts locally
  3716 fixed variables, and adds hilite markup for undeclared frees.
  3717 
  3718 * Unused theorems can be found using the new command 'unused_thms'.
  3719 There are three ways of invoking it:
  3720 
  3721 (1) unused_thms
  3722      Only finds unused theorems in the current theory.
  3723 
  3724 (2) unused_thms thy_1 ... thy_n -
  3725      Finds unused theorems in the current theory and all of its ancestors,
  3726      excluding the theories thy_1 ... thy_n and all of their ancestors.
  3727 
  3728 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  3729      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  3730      their ancestors, excluding the theories thy_1 ... thy_n and all of
  3731      their ancestors.
  3732 
  3733 In order to increase the readability of the list produced by
  3734 unused_thms, theorems that have been created by a particular instance
  3735 of a theory command such as 'inductive' or 'function' are considered
  3736 to belong to the same "group", meaning that if at least one theorem in
  3737 this group is used, the other theorems in the same group are no longer
  3738 reported as unused.  Moreover, if all theorems in the group are
  3739 unused, only one theorem in the group is displayed.
  3740 
  3741 Note that proof objects have to be switched on in order for
  3742 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  3743 usually the case when using Proof General with the default settings).
  3744 
  3745 * Authentic naming of facts disallows ad-hoc overwriting of previous
  3746 theorems within the same name space.  INCOMPATIBILITY, need to remove
  3747 duplicate fact bindings, or even accidental fact duplications.  Note
  3748 that tools may maintain dynamically scoped facts systematically, using
  3749 PureThy.add_thms_dynamic.
  3750 
  3751 * Command 'hide' now allows to hide from "fact" name space as well.
  3752 
  3753 * Eliminated destructive theorem database, simpset, claset, and
  3754 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  3755 update of theories within ML code.
  3756 
  3757 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  3758 INCOMPATIBILITY, object-logics depending on former Pure require
  3759 additional setup PureThy.old_appl_syntax_setup; object-logics
  3760 depending on former CPure need to refer to Pure.
  3761 
  3762 * Commands 'use' and 'ML' are now purely functional, operating on
  3763 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  3764 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  3765 INCOMPATIBILITY.
  3766 
  3767 * Command 'setup': discontinued implicit version with ML reference.
  3768 
  3769 * Instantiation target allows for simultaneous specification of class
  3770 instance operations together with an instantiation proof.
  3771 Type-checking phase allows to refer to class operations uniformly.
  3772 See src/HOL/Complex/Complex.thy for an Isar example and
  3773 src/HOL/Library/Eval.thy for an ML example.
  3774 
  3775 * Indexing of literal facts: be more serious about including only
  3776 facts from the visible specification/proof context, but not the
  3777 background context (locale etc.).  Affects `prop` notation and method
  3778 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  3779 situations.
  3780 
  3781 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  3782 "(open)" option, which used to expose internal bound variables to the
  3783 proof text.
  3784 
  3785 * Isar statements: removed obsolete case "rule_context".
  3786 INCOMPATIBILITY, better use explicit fixes/assumes.
  3787 
  3788 * Locale proofs: default proof step now includes 'unfold_locales';
  3789 hence 'proof' without argument may be used to unfold locale
  3790 predicates.
  3791 
  3792 
  3793 *** Document preparation ***
  3794 
  3795 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  3796 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  3797 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  3798 spot); renamed link color from "darkblue" to "linkcolor" (default
  3799 value unchanged, can be redefined via \definecolor); no longer sets
  3800 "a4paper" option (unnecessary or even intrusive).
  3801 
  3802 * Antiquotation @{lemma A method} proves proposition A by the given
  3803 method (either a method name or a method name plus (optional) method
  3804 arguments in parentheses) and prints A just like @{prop A}.
  3805 
  3806 
  3807 *** HOL ***
  3808 
  3809 * New primrec package.  Specification syntax conforms in style to
  3810 definition/function/....  No separate induction rule is provided.  The
  3811 "primrec" command distinguishes old-style and new-style specifications
  3812 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3813 When adjusting theories, beware: constants stemming from new-style
  3814 primrec specifications have authentic syntax.
  3815 
  3816 * Metis prover is now an order of magnitude faster, and also works
  3817 with multithreading.
  3818 
  3819 * Metis: the maximum number of clauses that can be produced from a
  3820 theorem is now given by the attribute max_clauses.  Theorems that
  3821 exceed this number are ignored, with a warning printed.
  3822 
  3823 * Sledgehammer no longer produces structured proofs by default. To
  3824 enable, declare [[sledgehammer_full = true]].  Attributes
  3825 reconstruction_modulus, reconstruction_sorts renamed
  3826 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3827 
  3828 * Method "induct_scheme" derives user-specified induction rules
  3829 from well-founded induction and completeness of patterns. This factors
  3830 out some operations that are done internally by the function package
  3831 and makes them available separately.  See
  3832 src/HOL/ex/Induction_Scheme.thy for examples.
  3833 
  3834 * More flexible generation of measure functions for termination
  3835 proofs: Measure functions can be declared by proving a rule of the
  3836 form "is_measure f" and giving it the [measure_function] attribute.
  3837 The "is_measure" predicate is logically meaningless (always true), and
  3838 just guides the heuristic.  To find suitable measure functions, the
  3839 termination prover sets up the goal "is_measure ?f" of the appropriate
  3840 type and generates all solutions by prolog-style backwards proof using
  3841 the declared rules.
  3842 
  3843 This setup also deals with rules like 
  3844 
  3845   "is_measure f ==> is_measure (list_size f)"
  3846 
  3847 which accommodates nested datatypes that recurse through lists.
  3848 Similar rules are predeclared for products and option types.
  3849 
  3850 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3851 
  3852   INCOMPATIBILITIES:
  3853 
  3854   - Definitions of overloaded constants on sets have to be replaced by
  3855     definitions on => and bool.
  3856 
  3857   - Some definitions of overloaded operators on sets can now be proved
  3858     using the definitions of the operators on => and bool.  Therefore,
  3859     the following theorems have been renamed:
  3860 
  3861       subset_def   -> subset_eq
  3862       psubset_def  -> psubset_eq
  3863       set_diff_def -> set_diff_eq
  3864       Compl_def    -> Compl_eq
  3865       Sup_set_def  -> Sup_set_eq
  3866       Inf_set_def  -> Inf_set_eq
  3867       sup_set_def  -> sup_set_eq
  3868       inf_set_def  -> inf_set_eq
  3869 
  3870   - Due to the incompleteness of the HO unification algorithm, some
  3871     rules such as subst may require manual instantiation, if some of
  3872     the unknowns in the rule is a set.
  3873 
  3874   - Higher order unification and forward proofs:
  3875     The proof pattern
  3876 
  3877       have "P (S::'a set)" <...>
  3878       then have "EX S. P S" ..
  3879 
  3880     no longer works (due to the incompleteness of the HO unification
  3881     algorithm) and must be replaced by the pattern
  3882 
  3883       have "EX S. P S"
  3884       proof
  3885         show "P S" <...>
  3886       qed
  3887 
  3888   - Calculational reasoning with subst (or similar rules):
  3889     The proof pattern
  3890 
  3891       have "P (S::'a set)" <...>
  3892       also have "S = T" <...>
  3893       finally have "P T" .
  3894 
  3895     no longer works (for similar reasons as the previous example) and
  3896     must be replaced by something like
  3897 
  3898       have "P (S::'a set)" <...>
  3899       moreover have "S = T" <...>
  3900       ultimately have "P T" by simp
  3901 
  3902   - Tactics or packages written in ML code:
  3903     Code performing pattern matching on types via
  3904 
  3905       Type ("set", [T]) => ...
  3906 
  3907     must be rewritten. Moreover, functions like strip_type or
  3908     binder_types no longer return the right value when applied to a
  3909     type of the form
  3910 
  3911       T1 => ... => Tn => U => bool
  3912 
  3913     rather than
  3914 
  3915       T1 => ... => Tn => U set
  3916 
  3917 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3918 Wellfounded_Relations to theory Wellfounded.
  3919 
  3920 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3921 
  3922 * Class finite no longer treats UNIV as class parameter.  Use class
  3923 enum from theory Library/Enum instead to achieve a similar effect.
  3924 INCOMPATIBILITY.
  3925 
  3926 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3927 and "Cons".  INCOMPATIBILITY.
  3928 
  3929 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3930 Potential INCOMPATIBILITY.
  3931 
  3932 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3933 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3934 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3935 
  3936 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3937 the same name in theory Orderings:
  3938 
  3939   less_trans
  3940   less_linear
  3941   le_imp_less_or_eq
  3942   le_less_trans
  3943   less_le_trans
  3944   less_not_sym
  3945   less_asym
  3946 
  3947 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3948 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3949 and different variable names.
  3950 
  3951 * Library/Option_ord.thy: Canonical order on option type.
  3952 
  3953 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3954 finite maps.
  3955 
  3956 * Library/Countable.thy: Type class for countable types.
  3957 
  3958 * Theory Int: The representation of numerals has changed.  The infix
  3959 operator BIT and the bit datatype with constructors B0 and B1 have
  3960 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3961 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3962 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3963 accordingly.
  3964 
  3965 * Theory Nat: definition of <= and < on natural numbers no longer
  3966 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3967 le_def and less_def have disappeared.  Consider lemmas not_less
  3968 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3969 
  3970 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3971 (whose purpose mainly is for various fold_set functionals) have been
  3972 abandoned in favor of the existing algebraic classes
  3973 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3974 lower_semilattice (resp. upper_semilattice) and linorder.
  3975 INCOMPATIBILITY.
  3976 
  3977 * Theory Transitive_Closure: induct and cases rules now declare proper
  3978 case_names ("base" and "step").  INCOMPATIBILITY.
  3979 
  3980 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3981 lattices.  The form set-specific version is available as
  3982 Inductive.lfp_ordinal_induct_set.
  3983 
  3984 * Renamed theorems "power.simps" to "power_int.simps".
  3985 INCOMPATIBILITY.
  3986 
  3987 * Class semiring_div provides basic abstract properties of semirings
  3988 with division and modulo operations.  Subsumes former class dvd_mod.
  3989 
  3990 * Merged theories IntDef, Numeral and IntArith into unified theory
  3991 Int.  INCOMPATIBILITY.
  3992 
  3993 * Theory Library/Code_Index: type "index" now represents natural
  3994 numbers rather than integers.  INCOMPATIBILITY.
  3995 
  3996 * New class "uminus" with operation "uminus" (split of from class
  3997 "minus" which now only has operation "minus", binary).
  3998 INCOMPATIBILITY.
  3999 
  4000 * Constants "card", "internal_split", "option_map" now with authentic
  4001 syntax.  INCOMPATIBILITY.
  4002 
  4003 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  4004 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  4005 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  4006 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  4007 Sup_set_def, le_def, less_def, option_map_def now with object
  4008 equality.  INCOMPATIBILITY.
  4009 
  4010 * Records. Removed K_record, and replaced it by pure lambda term
  4011 %x. c. The simplifier setup is now more robust against eta expansion.
  4012 INCOMPATIBILITY: in cases explicitly referring to K_record.
  4013 
  4014 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  4015 
  4016 * Library/ListVector: new theory of arithmetic vector operations.
  4017 
  4018 * Library/Order_Relation: new theory of various orderings as sets of
  4019 pairs.  Defines preorders, partial orders, linear orders and
  4020 well-orders on sets and on types.
  4021 
  4022 
  4023 *** ZF ***
  4024 
  4025 * Renamed some theories to allow to loading both ZF and HOL in the
  4026 same session:
  4027 
  4028   Datatype  -> Datatype_ZF
  4029   Inductive -> Inductive_ZF
  4030   Int       -> Int_ZF
  4031   IntDiv    -> IntDiv_ZF
  4032   Nat       -> Nat_ZF
  4033   List      -> List_ZF
  4034   Main      -> Main_ZF
  4035 
  4036 INCOMPATIBILITY: ZF theories that import individual theories below
  4037 Main might need to be adapted.  Regular theory Main is still
  4038 available, as trivial extension of Main_ZF.
  4039 
  4040 
  4041 *** ML ***
  4042 
  4043 * ML within Isar: antiquotation @{const name} or @{const
  4044 name(typargs)} produces statically-checked Const term.
  4045 
  4046 * Functor NamedThmsFun: data is available to the user as dynamic fact
  4047 (of the same name).  Removed obsolete print command.
  4048 
  4049 * Removed obsolete "use_legacy_bindings" function.
  4050 
  4051 * The ``print mode'' is now a thread-local value derived from a global
  4052 template (the former print_mode reference), thus access becomes
  4053 non-critical.  The global print_mode reference is for session
  4054 management only; user-code should use print_mode_value,
  4055 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  4056 
  4057 * Functions system/system_out provide a robust way to invoke external
  4058 shell commands, with propagation of interrupts (requires Poly/ML
  4059 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  4060 
  4061 
  4062 *** System ***
  4063 
  4064 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  4065 in accordance with Proof General 3.7, which prefers GNU emacs.
  4066 
  4067 * isatool tty runs Isabelle process with plain tty interaction;
  4068 optional line editor may be specified via ISABELLE_LINE_EDITOR
  4069 setting, the default settings attempt to locate "ledit" and "rlwrap".
  4070 
  4071 * isatool browser now works with Cygwin as well, using general
  4072 "javapath" function defined in Isabelle process environment.
  4073 
  4074 * YXML notation provides a simple and efficient alternative to
  4075 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  4076 isatool yxml as described in the Isabelle system manual.
  4077 
  4078 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  4079 provides general wrapper for managing an Isabelle process in a robust
  4080 fashion, with ``cooked'' output from stdin/stderr.
  4081 
  4082 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  4083 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  4084 
  4085 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  4086 way of changing the user's settings is via
  4087 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  4088 script.
  4089 
  4090 * Multithreading.max_threads := 0 refers to the number of actual CPU
  4091 cores of the underlying machine, which is a good starting point for
  4092 optimal performance tuning.  The corresponding usedir option -M allows
  4093 "max" as an alias for "0".  WARNING: does not work on certain versions
  4094 of Mac OS (with Poly/ML 5.1).
  4095 
  4096 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  4097 adverse effect of Isabelle flooding interactive front-ends (notably
  4098 ProofGeneral / XEmacs).
  4099 
  4100 
  4101 
  4102 New in Isabelle2007 (November 2007)
  4103 -----------------------------------
  4104 
  4105 *** General ***
  4106 
  4107 * More uniform information about legacy features, notably a
  4108 warning/error of "Legacy feature: ...", depending on the state of the
  4109 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  4110 legacy features will disappear eventually.
  4111 
  4112 * Theory syntax: the header format ``theory A = B + C:'' has been
  4113 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  4114 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  4115 
  4116 * Theory syntax: the old non-Isar theory file format has been
  4117 discontinued altogether.  Note that ML proof scripts may still be used
  4118 with Isar theories; migration is usually quite simple with the ML
  4119 function use_legacy_bindings.  INCOMPATIBILITY.
  4120 
  4121 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  4122 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  4123 quotes.
  4124 
  4125 * Theory loader: be more serious about observing the static theory
  4126 header specifications (including optional directories), but not the
  4127 accidental file locations of previously successful loads.  The strict
  4128 update policy of former update_thy is now already performed by
  4129 use_thy, so the former has been removed; use_thys updates several
  4130 theories simultaneously, just as 'imports' within a theory header
  4131 specification, but without merging the results.  Potential
  4132 INCOMPATIBILITY: may need to refine theory headers and commands
  4133 ROOT.ML which depend on load order.
  4134 
  4135 * Theory loader: optional support for content-based file
  4136 identification, instead of the traditional scheme of full physical
  4137 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  4138 (cf. the system manual).  The new scheme allows to work with
  4139 non-finished theories in persistent session images, such that source
  4140 files may be moved later on without requiring reloads.
  4141 
  4142 * Theory loader: old-style ML proof scripts being *attached* to a thy
  4143 file (with the same base name as the theory) are considered a legacy
  4144 feature, which will disappear eventually. Even now, the theory loader
  4145 no longer maintains dependencies on such files.
  4146 
  4147 * Syntax: the scope for resolving ambiguities via type-inference is
  4148 now limited to individual terms, instead of whole simultaneous
  4149 specifications as before. This greatly reduces the complexity of the
  4150 syntax module and improves flexibility by separating parsing and
  4151 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  4152 'fixes' etc.) are required in rare situations.
  4153 
  4154 * Syntax: constants introduced by new-style packages ('definition',
  4155 'abbreviation' etc.) are passed through the syntax module in
  4156 ``authentic mode''. This means that associated mixfix annotations
  4157 really stick to such constants, independently of potential name space
  4158 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  4159 trees are represented slightly differently, may need to adapt syntax
  4160 translations accordingly. Use CONST marker in 'translations' and
  4161 @{const_syntax} antiquotation in 'parse_translation' etc.
  4162 
  4163 * Legacy goal package: reduced interface to the bare minimum required
  4164 to keep existing proof scripts running.  Most other user-level
  4165 functions are now part of the OldGoals structure, which is *not* open
  4166 by default (consider isatool expandshort before open OldGoals).
  4167 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  4168 these tend to cause confusion about the actual goal (!) context being
  4169 used here, which is not necessarily the same as the_context().
  4170 
  4171 * Command 'find_theorems': supports "*" wild-card in "name:"
  4172 criterion; "with_dups" option.  Certain ProofGeneral versions might
  4173 support a specific search form (see ProofGeneral/CHANGES).
  4174 
  4175 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  4176 by default, which means that "prems" (and also "fixed variables") are
  4177 suppressed from proof state output.  Note that the ProofGeneral
  4178 settings mechanism allows to change and save options persistently, but
  4179 older versions of Isabelle will fail to start up if a negative prems
  4180 limit is imposed.
  4181 
  4182 * Local theory targets may be specified by non-nested blocks of
  4183 ``context/locale/class ... begin'' followed by ``end''.  The body may
  4184 contain definitions, theorems etc., including any derived mechanism
  4185 that has been implemented on top of these primitives.  This concept
  4186 generalizes the existing ``theorem (in ...)'' towards more versatility
  4187 and scalability.
  4188 
  4189 * Proof General interface: proper undo of final 'end' command;
  4190 discontinued Isabelle/classic mode (ML proof scripts).
  4191 
  4192 
  4193 *** Document preparation ***
  4194 
  4195 * Added antiquotation @{theory name} which prints the given name,
  4196 after checking that it refers to a valid ancestor theory in the
  4197 current context.
  4198 
  4199 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  4200 check the given source text as ML type/structure, printing verbatim.
  4201 
  4202 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  4203 "c args == rhs" given in the current context.  (Any number of
  4204 arguments may be given on the LHS.)
  4205 
  4206 
  4207 *** Pure ***
  4208 
  4209 * The 'class' package offers a combination of axclass and locale to
  4210 achieve Haskell-like type classes in Isabelle.  Definitions and
  4211 theorems within a class context produce both relative results (with
  4212 implicit parameters according to the locale context), and polymorphic
  4213 constants with qualified polymorphism (according to the class
  4214 context).  Within the body context of a 'class' target, a separate
  4215 syntax layer ("user space type system") takes care of converting
  4216 between global polymorphic consts and internal locale representation.
  4217 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  4218 "isatool doc classes" provides a tutorial.
  4219 
  4220 * Generic code generator framework allows to generate executable
  4221 code for ML and Haskell (including Isabelle classes).  A short usage
  4222 sketch:
  4223 
  4224     internal compilation:
  4225         export_code <list of constants (term syntax)> in SML
  4226     writing SML code to a file:
  4227         export_code <list of constants (term syntax)> in SML <filename>
  4228     writing OCaml code to a file:
  4229         export_code <list of constants (term syntax)> in OCaml <filename>
  4230     writing Haskell code to a bunch of files:
  4231         export_code <list of constants (term syntax)> in Haskell <filename>
  4232 
  4233     evaluating closed propositions to True/False using code generation:
  4234         method ``eval''
  4235 
  4236 Reasonable default setup of framework in HOL.
  4237 
  4238 Theorem attributs for selecting and transforming function equations theorems:
  4239 
  4240     [code fun]:        select a theorem as function equation for a specific constant
  4241     [code fun del]:    deselect a theorem as function equation for a specific constant
  4242     [code inline]:     select an equation theorem for unfolding (inlining) in place
  4243     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  4244 
  4245 User-defined serializations (target in {SML, OCaml, Haskell}):
  4246 
  4247     code_const <and-list of constants (term syntax)>
  4248       {(target) <and-list of const target syntax>}+
  4249 
  4250     code_type <and-list of type constructors>
  4251       {(target) <and-list of type target syntax>}+
  4252 
  4253     code_instance <and-list of instances>
  4254       {(target)}+
  4255         where instance ::= <type constructor> :: <class>
  4256 
  4257     code_class <and_list of classes>
  4258       {(target) <and-list of class target syntax>}+
  4259         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  4260 
  4261 code_instance and code_class only are effective to target Haskell.
  4262 
  4263 For example usage see src/HOL/ex/Codegenerator.thy and
  4264 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  4265 generation from Isabelle/HOL theories is available via "isatool doc
  4266 codegen".
  4267 
  4268 * Code generator: consts in 'consts_code' Isar commands are now
  4269 referred to by usual term syntax (including optional type
  4270 annotations).
  4271 
  4272 * Command 'no_translations' removes translation rules from theory
  4273 syntax.
  4274 
  4275 * Overloaded definitions are now actually checked for acyclic
  4276 dependencies.  The overloading scheme is slightly more general than
  4277 that of Haskell98, although Isabelle does not demand an exact
  4278 correspondence to type class and instance declarations.
  4279 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4280 exotic versions of overloading -- at the discretion of the user!
  4281 
  4282 Polymorphic constants are represented via type arguments, i.e. the
  4283 instantiation that matches an instance against the most general
  4284 declaration given in the signature.  For example, with the declaration
  4285 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4286 as c(nat).  Overloading is essentially simultaneous structural
  4287 recursion over such type arguments.  Incomplete specification patterns
  4288 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4289 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4290 Command 'print_theory' outputs the normalized system of recursive
  4291 equations, see section "definitions".
  4292 
  4293 * Configuration options are maintained within the theory or proof
  4294 context (with name and type bool/int/string), providing a very simple
  4295 interface to a poor-man's version of general context data.  Tools may
  4296 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4297 these values using Config.get etc.  Users may change options via an
  4298 associated attribute of the same name.  This form of context
  4299 declaration works particularly well with commands 'declare' or
  4300 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4301 very easy to avoid global references, which would not observe Isar
  4302 toplevel undo/redo and fail to work with multithreading.
  4303 
  4304 Various global ML references of Pure and HOL have been turned into
  4305 configuration options:
  4306 
  4307   Unify.search_bound		unify_search_bound
  4308   Unify.trace_bound		unify_trace_bound
  4309   Unify.trace_simp		unify_trace_simp
  4310   Unify.trace_types		unify_trace_types
  4311   Simplifier.simp_depth_limit	simp_depth_limit
  4312   Blast.depth_limit		blast_depth_limit
  4313   DatatypeProp.dtK		datatype_distinctness_limit
  4314   fast_arith_neq_limit  	fast_arith_neq_limit
  4315   fast_arith_split_limit	fast_arith_split_limit
  4316 
  4317 * Named collections of theorems may be easily installed as context
  4318 data using the functor NamedThmsFun (see also
  4319 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4320 attributes; there is also a toplevel print command.  This facility is
  4321 just a common case of general context data, which is the preferred way
  4322 for anything more complex than just a list of facts in canonical
  4323 order.
  4324 
  4325 * Isar: command 'declaration' augments a local theory by generic
  4326 declaration functions written in ML.  This enables arbitrary content
  4327 being added to the context, depending on a morphism that tells the
  4328 difference of the original declaration context wrt. the application
  4329 context encountered later on.
  4330 
  4331 * Isar: proper interfaces for simplification procedures.  Command
  4332 'simproc_setup' declares named simprocs (with match patterns, and body
  4333 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4334 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4335 
  4336 * Isar: an extra pair of brackets around attribute declarations
  4337 abbreviates a theorem reference involving an internal dummy fact,
  4338 which will be ignored later --- only the effect of the attribute on
  4339 the background context will persist.  This form of in-place
  4340 declarations is particularly useful with commands like 'declare' and
  4341 'using', for example ``have A using [[simproc a]] by simp''.
  4342 
  4343 * Isar: method "assumption" (and implicit closing of subproofs) now
  4344 takes simple non-atomic goal assumptions into account: after applying
  4345 an assumption as a rule the resulting subgoals are solved by atomic
  4346 assumption steps.  This is particularly useful to finish 'obtain'
  4347 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4348 without referring to the original premise "!!x. P x ==> thesis" in the
  4349 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4350 more permissive.
  4351 
  4352 * Isar: implicit use of prems from the Isar proof context is
  4353 considered a legacy feature.  Common applications like ``have A .''
  4354 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4355 referencing facts explicitly here improves readability and
  4356 maintainability of proof texts.
  4357 
  4358 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4359 the obtained context from the course of reasoning!  For example:
  4360 
  4361   assume "EX x y. A x & B y"   -- "any previous fact"
  4362   then guess x and y by clarify
  4363 
  4364 This technique is potentially adventurous, depending on the facts and
  4365 proof tools being involved here.
  4366 
  4367 * Isar: known facts from the proof context may be specified as literal
  4368 propositions, using ASCII back-quote syntax.  This works wherever
  4369 named facts used to be allowed so far, in proof commands, proof
  4370 methods, attributes etc.  Literal facts are retrieved from the context
  4371 according to unification of type and term parameters.  For example,
  4372 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4373 theorems in the current context, then these are valid literal facts:
  4374 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4375 
  4376 There is also a proof method "fact" which does the same composition
  4377 for explicit goal states, e.g. the following proof texts coincide with
  4378 certain special cases of literal facts:
  4379 
  4380   have "A" by fact                 ==  note `A`
  4381   have "A ==> B" by fact           ==  note `A ==> B`
  4382   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4383   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4384 
  4385 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4386 outer syntax.  Thus symbolic identifiers may be used without
  4387 additional white space in declarations like this: ``assume *: A''.
  4388 
  4389 * Isar: 'print_facts' prints all local facts of the current context,
  4390 both named and unnamed ones.
  4391 
  4392 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4393 
  4394   def x == "t" and y == "u"
  4395 
  4396 * Isar: added command 'unfolding', which is structurally similar to
  4397 'using', but affects both the goal state and facts by unfolding given
  4398 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4399 'unfolded' attribute may be replaced by first-class proof text.
  4400 
  4401 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4402 and command 'unfolding' now all support object-level equalities
  4403 (potentially conditional).  The underlying notion of rewrite rule is
  4404 analogous to the 'rule_format' attribute, but *not* that of the
  4405 Simplifier (which is usually more generous).
  4406 
  4407 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4408 premises of a theorem by n. Useful in conjunction with drule.
  4409 
  4410 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4411 method expression within a sandbox consisting of the first N
  4412 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4413 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4414 simplifies all new goals that emerge from applying rule foo to the
  4415 originally first one.
  4416 
  4417 * Isar: schematic goals are no longer restricted to higher-order
  4418 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  4419 expected.
  4420 
  4421 * Isar: the conclusion of a long theorem statement is now either
  4422 'shows' (a simultaneous conjunction, as before), or 'obtains'
  4423 (essentially a disjunction of cases with local parameters and
  4424 assumptions).  The latter allows to express general elimination rules
  4425 adequately; in this notation common elimination rules look like this:
  4426 
  4427   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  4428     assumes "EX x. P x"
  4429     obtains x where "P x"
  4430 
  4431   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  4432     assumes "A & B"
  4433     obtains A and B
  4434 
  4435   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  4436     assumes "A | B"
  4437     obtains
  4438       A
  4439     | B
  4440 
  4441 The subsequent classical rules even refer to the formal "thesis"
  4442 explicitly:
  4443 
  4444   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  4445     obtains "~ thesis"
  4446 
  4447   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  4448     obtains "thesis ==> something"
  4449 
  4450 The actual proof of an 'obtains' statement is analogous to that of the
  4451 Isar proof element 'obtain', only that there may be several cases.
  4452 Optional case names may be specified in parentheses; these will be
  4453 available both in the present proof and as annotations in the
  4454 resulting rule, for later use with the 'cases' method (cf. attribute
  4455 case_names).
  4456 
  4457 * Isar: the assumptions of a long theorem statement are available as
  4458 "assms" fact in the proof context.  This is more appropriate than the
  4459 (historical) "prems", which refers to all assumptions of the current
  4460 context, including those from the target locale, proof body etc.
  4461 
  4462 * Isar: 'print_statement' prints theorems from the current theory or
  4463 proof context in long statement form, according to the syntax of a
  4464 top-level lemma.
  4465 
  4466 * Isar: 'obtain' takes an optional case name for the local context
  4467 introduction rule (default "that").
  4468 
  4469 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  4470 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  4471 to occur.
  4472 
  4473 * Pure: syntax "CONST name" produces a fully internalized constant
  4474 according to the current context.  This is particularly useful for
  4475 syntax translations that should refer to internal constant
  4476 representations independently of name spaces.
  4477 
  4478 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  4479 instead of "FOO ". This allows multiple binder declarations to coexist
  4480 in the same context.  INCOMPATIBILITY.
  4481 
  4482 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  4483 primitive that also works in a locale context (both for constants and
  4484 fixed variables). Type declaration and internal syntactic representation
  4485 of given constants retrieved from the context. Likewise, the
  4486 'no_notation' command allows to remove given syntax annotations from the
  4487 current context.
  4488 
  4489 * Isar/locales: new derived specification elements 'axiomatization',
  4490 'definition', 'abbreviation', which support type-inference, admit
  4491 object-level specifications (equality, equivalence).  See also the
  4492 isar-ref manual.  Examples:
  4493 
  4494   axiomatization
  4495     eq  (infix "===" 50) where
  4496     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  4497 
  4498   definition "f x y = x + y + 1"
  4499   definition g where "g x = f x x"
  4500 
  4501   abbreviation
  4502     neq  (infix "=!=" 50) where
  4503     "x =!= y == ~ (x === y)"
  4504 
  4505 These specifications may be also used in a locale context.  Then the
  4506 constants being introduced depend on certain fixed parameters, and the
  4507 constant name is qualified by the locale base name.  An internal
  4508 abbreviation takes care for convenient input and output, making the
  4509 parameters implicit and using the original short name.  See also
  4510 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  4511 entities from a monomorphic theory.
  4512 
  4513 Presently, abbreviations are only available 'in' a target locale, but
  4514 not inherited by general import expressions.  Also note that
  4515 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  4516 'translations' in common applications.  The "no_abbrevs" print mode
  4517 prevents folding of abbreviations in term output.
  4518 
  4519 Concrete syntax is attached to specified constants in internal form,
  4520 independently of name spaces.  The parse tree representation is
  4521 slightly different -- use 'notation' instead of raw 'syntax', and
  4522 'translations' with explicit "CONST" markup to accommodate this.
  4523 
  4524 * Pure/Isar: unified syntax for new-style specification mechanisms
  4525 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  4526 full type inference and dummy patterns ("_").  For example:
  4527 
  4528   definition "K x _ = x"
  4529 
  4530   inductive conj for A B
  4531   where "A ==> B ==> conj A B"
  4532 
  4533 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  4534 the current context.  Print mode "no_abbrevs" prevents inversion of
  4535 abbreviations on output.
  4536 
  4537 * Isar/locales: improved parameter handling: use of locales "var" and
  4538 "struct" no longer necessary; - parameter renamings are no longer
  4539 required to be injective.  For example, this allows to define
  4540 endomorphisms as locale endom = homom mult mult h.
  4541 
  4542 * Isar/locales: changed the way locales with predicates are defined.
  4543 Instead of accumulating the specification, the imported expression is
  4544 now an interpretation.  INCOMPATIBILITY: different normal form of
  4545 locale expressions.  In particular, in interpretations of locales with
  4546 predicates, goals repesenting already interpreted fragments are not
  4547 removed automatically.  Use methods `intro_locales' and
  4548 `unfold_locales'; see below.
  4549 
  4550 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  4551 provide backward reasoning on locales predicates.  The methods are
  4552 aware of interpretations and discharge corresponding goals.
  4553 `intro_locales' is less aggressive then `unfold_locales' and does not
  4554 unfold predicates to assumptions.
  4555 
  4556 * Isar/locales: the order in which locale fragments are accumulated
  4557 has changed.  This enables to override declarations from fragments due
  4558 to interpretations -- for example, unwanted simp rules.
  4559 
  4560 * Isar/locales: interpretation in theories and proof contexts has been
  4561 extended.  One may now specify (and prove) equations, which are
  4562 unfolded in interpreted theorems.  This is useful for replacing
  4563 defined concepts (constants depending on locale parameters) by
  4564 concepts already existing in the target context.  Example:
  4565 
  4566   interpretation partial_order ["op <= :: [int, int] => bool"]
  4567     where "partial_order.less (op <=) (x::int) y = (x < y)"
  4568 
  4569 Typically, the constant `partial_order.less' is created by a
  4570 definition specification element in the context of locale
  4571 partial_order.
  4572 
  4573 * Method "induct": improved internal context management to support
  4574 local fixes and defines on-the-fly. Thus explicit meta-level
  4575 connectives !!  and ==> are rarely required anymore in inductive goals
  4576 (using object-logic connectives for this purpose has been long
  4577 obsolete anyway). Common proof patterns are explained in
  4578 src/HOL/Induct/Common_Patterns.thy, see also
  4579 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  4580 examples.
  4581 
  4582 * Method "induct": improved handling of simultaneous goals. Instead of
  4583 introducing object-level conjunction, the statement is now split into
  4584 several conclusions, while the corresponding symbolic cases are nested
  4585 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  4586 see src/HOL/Induct/Common_Patterns.thy, for example.
  4587 
  4588 * Method "induct": mutual induction rules are now specified as a list
  4589 of rule sharing the same induction cases. HOL packages usually provide
  4590 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  4591 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  4592 mutual induction rules differently, i.e. like this:
  4593 
  4594   (induct rule: foo_bar.inducts)
  4595   (induct set: foo bar)
  4596   (induct pred: foo bar)
  4597   (induct type: foo bar)
  4598 
  4599 The ML function ProjectRule.projections turns old-style rules into the
  4600 new format.
  4601 
  4602 * Method "coinduct": dual of induction, see
  4603 src/HOL/Library/Coinductive_List.thy for various examples.
  4604 
  4605 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  4606 considered a legacy feature.
  4607 
  4608 * Attribute "symmetric" produces result with standardized schematic
  4609 variables (index 0).  Potential INCOMPATIBILITY.
  4610 
  4611 * Simplifier: by default the simplifier trace only shows top level
  4612 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  4613 default. Thus there is less danger of being flooded by the trace. The
  4614 trace indicates where parts have been suppressed.
  4615   
  4616 * Provers/classical: removed obsolete classical version of elim_format
  4617 attribute; classical elim/dest rules are now treated uniformly when
  4618 manipulating the claset.
  4619 
  4620 * Provers/classical: stricter checks to ensure that supplied intro,
  4621 dest and elim rules are well-formed; dest and elim rules must have at
  4622 least one premise.
  4623 
  4624 * Provers/classical: attributes dest/elim/intro take an optional
  4625 weight argument for the rule (just as the Pure versions).  Weights are
  4626 ignored by automated tools, but determine the search order of single
  4627 rule steps.
  4628 
  4629 * Syntax: input syntax now supports dummy variable binding "%_. b",
  4630 where the body does not mention the bound variable.  Note that dummy
  4631 patterns implicitly depend on their context of bounds, which makes
  4632 "{_. _}" match any set comprehension as expected.  Potential
  4633 INCOMPATIBILITY -- parse translations need to cope with syntactic
  4634 constant "_idtdummy" in the binding position.
  4635 
  4636 * Syntax: removed obsolete syntactic constant "_K" and its associated
  4637 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  4638 for example "A -> B" => "Pi A (%_. B)".
  4639 
  4640 * Pure: 'class_deps' command visualizes the subclass relation, using
  4641 the graph browser tool.
  4642 
  4643 * Pure: 'print_theory' now suppresses certain internal declarations by
  4644 default; use '!' option for full details.
  4645 
  4646 
  4647 *** HOL ***
  4648 
  4649 * Method "metis" proves goals by applying the Metis general-purpose
  4650 resolution prover (see also http://gilith.com/software/metis/).
  4651 Examples are in the directory MetisExamples.  WARNING: the
  4652 Isabelle/HOL-Metis integration does not yet work properly with
  4653 multi-threading.
  4654   
  4655 * Command 'sledgehammer' invokes external automatic theorem provers as
  4656 background processes.  It generates calls to the "metis" method if
  4657 successful. These can be pasted into the proof.  Users do not have to
  4658 wait for the automatic provers to return.  WARNING: does not really
  4659 work with multi-threading.
  4660 
  4661 * New "auto_quickcheck" feature tests outermost goal statements for
  4662 potential counter-examples.  Controlled by ML references
  4663 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  4664 5000 milliseconds).  Fails silently if statements is outside of
  4665 executable fragment, or any other codgenerator problem occurs.
  4666 
  4667 * New constant "undefined" with axiom "undefined x = undefined".
  4668 
  4669 * Added class "HOL.eq", allowing for code generation with polymorphic
  4670 equality.
  4671 
  4672 * Some renaming of class constants due to canonical name prefixing in
  4673 the new 'class' package:
  4674 
  4675     HOL.abs ~> HOL.abs_class.abs
  4676     HOL.divide ~> HOL.divide_class.divide
  4677     0 ~> HOL.zero_class.zero
  4678     1 ~> HOL.one_class.one
  4679     op + ~> HOL.plus_class.plus
  4680     op - ~> HOL.minus_class.minus
  4681     uminus ~> HOL.minus_class.uminus
  4682     op * ~> HOL.times_class.times
  4683     op < ~> HOL.ord_class.less
  4684     op <= > HOL.ord_class.less_eq
  4685     Nat.power ~> Power.power_class.power
  4686     Nat.size ~> Nat.size_class.size
  4687     Numeral.number_of ~> Numeral.number_class.number_of
  4688     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  4689     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  4690     Orderings.min ~> Orderings.ord_class.min
  4691     Orderings.max ~> Orderings.ord_class.max
  4692     Divides.op div ~> Divides.div_class.div
  4693     Divides.op mod ~> Divides.div_class.mod
  4694     Divides.op dvd ~> Divides.div_class.dvd
  4695 
  4696 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  4697 
  4698 a) User-defined constants using any of the names "plus", "minus",
  4699 "times", "less" or "less_eq". The standard syntax translations for
  4700 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  4701 names.
  4702 
  4703 b) Variables named "plus", "minus", "times", "less", "less_eq"
  4704 INCOMPATIBILITY: use more specific names.
  4705 
  4706 c) Permutative equations (e.g. "a + b = b + a")
  4707 Since the change of names also changes the order of terms, permutative
  4708 rewrite rules may get applied in a different order. Experience shows
  4709 that this is rarely the case (only two adaptions in the whole Isabelle
  4710 distribution).  INCOMPATIBILITY: rewrite proofs
  4711 
  4712 d) ML code directly refering to constant names
  4713 This in general only affects hand-written proof tactics, simprocs and
  4714 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  4715 Consider using @{const_name} antiquotation.
  4716 
  4717 * New class "default" with associated constant "default".
  4718 
  4719 * Function "sgn" is now overloaded and available on int, real, complex
  4720 (and other numeric types), using class "sgn".  Two possible defs of
  4721 sgn are given as equational assumptions in the classes sgn_if and
  4722 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  4723 INCOMPATIBILITY.
  4724 
  4725 * Locale "partial_order" now unified with class "order" (cf. theory
  4726 Orderings), added parameter "less".  INCOMPATIBILITY.
  4727 
  4728 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  4729 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  4730 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  4731 
  4732 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  4733 changed order of proof goals in instance proofs.
  4734 
  4735 * The transitivity reasoner for partial and linear orders is set up
  4736 for classes "order" and "linorder".  Instances of the reasoner are available
  4737 in all contexts importing or interpreting the corresponding locales.
  4738 Method "order" invokes the reasoner separately; the reasoner
  4739 is also integrated with the Simplifier as a solver.  Diagnostic
  4740 command 'print_orders' shows the available instances of the reasoner
  4741 in the current context.
  4742 
  4743 * Localized monotonicity predicate in theory "Orderings"; integrated
  4744 lemmas max_of_mono and min_of_mono with this predicate.
  4745 INCOMPATIBILITY.
  4746 
  4747 * Formulation of theorem "dense" changed slightly due to integration
  4748 with new class dense_linear_order.
  4749 
  4750 * Uniform lattice theory development in HOL.
  4751 
  4752     constants "meet" and "join" now named "inf" and "sup"
  4753     constant "Meet" now named "Inf"
  4754 
  4755     classes "meet_semilorder" and "join_semilorder" now named
  4756       "lower_semilattice" and "upper_semilattice"
  4757     class "lorder" now named "lattice"
  4758     class "comp_lat" now named "complete_lattice"
  4759 
  4760     Instantiation of lattice classes allows explicit definitions
  4761     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  4762 
  4763   INCOMPATIBILITY.  Theorem renames:
  4764 
  4765     meet_left_le            ~> inf_le1
  4766     meet_right_le           ~> inf_le2
  4767     join_left_le            ~> sup_ge1
  4768     join_right_le           ~> sup_ge2
  4769     meet_join_le            ~> inf_sup_ord
  4770     le_meetI                ~> le_infI
  4771     join_leI                ~> le_supI
  4772     le_meet                 ~> le_inf_iff
  4773     le_join                 ~> ge_sup_conv
  4774     meet_idempotent         ~> inf_idem
  4775     join_idempotent         ~> sup_idem
  4776     meet_comm               ~> inf_commute
  4777     join_comm               ~> sup_commute
  4778     meet_leI1               ~> le_infI1
  4779     meet_leI2               ~> le_infI2
  4780     le_joinI1               ~> le_supI1
  4781     le_joinI2               ~> le_supI2
  4782     meet_assoc              ~> inf_assoc
  4783     join_assoc              ~> sup_assoc
  4784     meet_left_comm          ~> inf_left_commute
  4785     meet_left_idempotent    ~> inf_left_idem
  4786     join_left_comm          ~> sup_left_commute
  4787     join_left_idempotent    ~> sup_left_idem
  4788     meet_aci                ~> inf_aci
  4789     join_aci                ~> sup_aci
  4790     le_def_meet             ~> le_iff_inf
  4791     le_def_join             ~> le_iff_sup
  4792     join_absorp2            ~> sup_absorb2
  4793     join_absorp1            ~> sup_absorb1
  4794     meet_absorp1            ~> inf_absorb1
  4795     meet_absorp2            ~> inf_absorb2
  4796     meet_join_absorp        ~> inf_sup_absorb
  4797     join_meet_absorp        ~> sup_inf_absorb
  4798     distrib_join_le         ~> distrib_sup_le
  4799     distrib_meet_le         ~> distrib_inf_le
  4800 
  4801     add_meet_distrib_left   ~> add_inf_distrib_left
  4802     add_join_distrib_left   ~> add_sup_distrib_left
  4803     is_join_neg_meet        ~> is_join_neg_inf
  4804     is_meet_neg_join        ~> is_meet_neg_sup
  4805     add_meet_distrib_right  ~> add_inf_distrib_right
  4806     add_join_distrib_right  ~> add_sup_distrib_right
  4807     add_meet_join_distribs  ~> add_sup_inf_distribs
  4808     join_eq_neg_meet        ~> sup_eq_neg_inf
  4809     meet_eq_neg_join        ~> inf_eq_neg_sup
  4810     add_eq_meet_join        ~> add_eq_inf_sup
  4811     meet_0_imp_0            ~> inf_0_imp_0
  4812     join_0_imp_0            ~> sup_0_imp_0
  4813     meet_0_eq_0             ~> inf_0_eq_0
  4814     join_0_eq_0             ~> sup_0_eq_0
  4815     neg_meet_eq_join        ~> neg_inf_eq_sup
  4816     neg_join_eq_meet        ~> neg_sup_eq_inf
  4817     join_eq_if              ~> sup_eq_if
  4818 
  4819     mono_meet               ~> mono_inf
  4820     mono_join               ~> mono_sup
  4821     meet_bool_eq            ~> inf_bool_eq
  4822     join_bool_eq            ~> sup_bool_eq
  4823     meet_fun_eq             ~> inf_fun_eq
  4824     join_fun_eq             ~> sup_fun_eq
  4825     meet_set_eq             ~> inf_set_eq
  4826     join_set_eq             ~> sup_set_eq
  4827     meet1_iff               ~> inf1_iff
  4828     meet2_iff               ~> inf2_iff
  4829     meet1I                  ~> inf1I
  4830     meet2I                  ~> inf2I
  4831     meet1D1                 ~> inf1D1
  4832     meet2D1                 ~> inf2D1
  4833     meet1D2                 ~> inf1D2
  4834     meet2D2                 ~> inf2D2
  4835     meet1E                  ~> inf1E
  4836     meet2E                  ~> inf2E
  4837     join1_iff               ~> sup1_iff
  4838     join2_iff               ~> sup2_iff
  4839     join1I1                 ~> sup1I1
  4840     join2I1                 ~> sup2I1
  4841     join1I1                 ~> sup1I1
  4842     join2I2                 ~> sup1I2
  4843     join1CI                 ~> sup1CI
  4844     join2CI                 ~> sup2CI
  4845     join1E                  ~> sup1E
  4846     join2E                  ~> sup2E
  4847 
  4848     is_meet_Meet            ~> is_meet_Inf
  4849     Meet_bool_def           ~> Inf_bool_def
  4850     Meet_fun_def            ~> Inf_fun_def
  4851     Meet_greatest           ~> Inf_greatest
  4852     Meet_lower              ~> Inf_lower
  4853     Meet_set_def            ~> Inf_set_def
  4854 
  4855     Sup_def                 ~> Sup_Inf
  4856     Sup_bool_eq             ~> Sup_bool_def
  4857     Sup_fun_eq              ~> Sup_fun_def
  4858     Sup_set_eq              ~> Sup_set_def
  4859 
  4860     listsp_meetI            ~> listsp_infI
  4861     listsp_meet_eq          ~> listsp_inf_eq
  4862 
  4863     meet_min                ~> inf_min
  4864     join_max                ~> sup_max
  4865 
  4866 * Added syntactic class "size"; overloaded constant "size" now has
  4867 type "'a::size ==> bool"
  4868 
  4869 * Internal reorganisation of `size' of datatypes: size theorems
  4870 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4871 simplification rules by default!); theorems "prod.size" now named
  4872 "*.size".
  4873 
  4874 * Class "div" now inherits from class "times" rather than "type".
  4875 INCOMPATIBILITY.
  4876 
  4877 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4878 Linorder etc.  have disappeared; operations defined in terms of
  4879 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4880 
  4881 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4882 
  4883 * HOL-Word: New extensive library and type for generic, fixed size
  4884 machine words, with arithmetic, bit-wise, shifting and rotating
  4885 operations, reflection into int, nat, and bool lists, automation for
  4886 linear arithmetic (by automatic reflection into nat or int), including
  4887 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4888 arithmetic type classes, supporting automatic simplification of
  4889 numerals on all operations.
  4890 
  4891 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4892 
  4893 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4894 
  4895 * Code generator library theories:
  4896   - Code_Integer represents HOL integers by big integer literals in target
  4897     languages.
  4898   - Code_Char represents HOL characters by character literals in target
  4899     languages.
  4900   - Code_Char_chr like Code_Char, but also offers treatment of character
  4901     codes; includes Code_Integer.
  4902   - Executable_Set allows to generate code for finite sets using lists.
  4903   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4904     denominator).
  4905   - Executable_Real implements a subset of real numbers, namly those
  4906     representable by rational numbers.
  4907   - Efficient_Nat implements natural numbers by integers, which in general will
  4908     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4909     includes Code_Integer.
  4910   - Code_Index provides an additional datatype index which is mapped to
  4911     target-language built-in integers.
  4912   - Code_Message provides an additional datatype message_string which is isomorphic to
  4913     strings; messages are mapped to target-language strings.
  4914 
  4915 * New package for inductive predicates
  4916 
  4917   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4918 
  4919     inductive
  4920       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4921       for z_1 :: U_1 and ... and z_n :: U_m
  4922     where
  4923       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4924     | ...
  4925 
  4926   with full support for type-inference, rather than
  4927 
  4928     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4929 
  4930     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4931     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4932 
  4933     inductive "s z_1 ... z_m"
  4934     intros
  4935       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4936       ...
  4937 
  4938   For backward compatibility, there is a wrapper allowing inductive
  4939   sets to be defined with the new package via
  4940 
  4941     inductive_set
  4942       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4943       for z_1 :: U_1 and ... and z_n :: U_m
  4944     where
  4945       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4946     | ...
  4947 
  4948   or
  4949 
  4950     inductive_set
  4951       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4952       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4953       for z_1 :: U_1 and ... and z_n :: U_m
  4954     where
  4955       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4956     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4957     | ...
  4958 
  4959   if the additional syntax "p ..." is required.
  4960 
  4961   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4962   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4963 
  4964   INCOMPATIBILITIES:
  4965 
  4966   - Since declaration and definition of inductive sets or predicates
  4967     is no longer separated, abbreviations involving the newly
  4968     introduced sets or predicates must be specified together with the
  4969     introduction rules after the 'where' keyword (see above), rather
  4970     than before the actual inductive definition.
  4971 
  4972   - The variables in induction and elimination rules are now
  4973     quantified in the order of their occurrence in the introduction
  4974     rules, rather than in alphabetical order. Since this may break
  4975     some proofs, these proofs either have to be repaired, e.g. by
  4976     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4977     statements of the form
  4978 
  4979       case (rule_i a_i_1 ... a_i_{k_i})
  4980 
  4981     or the old order of quantification has to be restored by explicitly adding
  4982     meta-level quantifiers in the introduction rules, i.e.
  4983 
  4984       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4985 
  4986   - The format of the elimination rules is now
  4987 
  4988       p z_1 ... z_m x_1 ... x_n ==>
  4989         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4990         ==> ... ==> P
  4991 
  4992     for predicates and
  4993 
  4994       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4995         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4996         ==> ... ==> P
  4997 
  4998     for sets rather than
  4999 
  5000       x : s z_1 ... z_m ==>
  5001         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  5002         ==> ... ==> P
  5003 
  5004     This may require terms in goals to be expanded to n-tuples
  5005     (e.g. using case_tac or simplification with the split_paired_all
  5006     rule) before the above elimination rule is applicable.
  5007 
  5008   - The elimination or case analysis rules for (mutually) inductive
  5009     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  5010     list of rules "p_1_..._p_k.elims" is no longer available.
  5011 
  5012 * New package "function"/"fun" for general recursive functions,
  5013 supporting mutual and nested recursion, definitions in local contexts,
  5014 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  5015 for small examples, and the separate tutorial on the function
  5016 package. The old recdef "package" is still available as before, but
  5017 users are encouraged to use the new package.
  5018 
  5019 * Method "lexicographic_order" automatically synthesizes termination
  5020 relations as lexicographic combinations of size measures. 
  5021 
  5022 * Case-expressions allow arbitrary constructor-patterns (including
  5023 "_") and take their order into account, like in functional
  5024 programming.  Internally, this is translated into nested
  5025 case-expressions; missing cases are added and mapped to the predefined
  5026 constant "undefined". In complicated cases printing may no longer show
  5027 the original input but the internal form. Lambda-abstractions allow
  5028 the same form of pattern matching: "% pat1 => e1 | ..." is an
  5029 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  5030 variable.
  5031 
  5032 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  5033 is an abbreviation for "of_nat :: nat => int". The simplification
  5034 rules for "of_nat" have been changed to work like "int" did
  5035 previously.  Potential INCOMPATIBILITY:
  5036   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  5037   - of_nat_diff and of_nat_mult are no longer default simp rules
  5038 
  5039 * Method "algebra" solves polynomial equations over (semi)rings using
  5040 Groebner bases. The (semi)ring structure is defined by locales and the
  5041 tool setup depends on that generic context. Installing the method for
  5042 a specific type involves instantiating the locale and possibly adding
  5043 declarations for computation on the coefficients.  The method is
  5044 already instantiated for natural numbers and for the axiomatic class
  5045 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  5046 CALCULEMUS 2007 for the general principles underlying this
  5047 architecture of context-aware proof-tools.
  5048 
  5049 * Method "ferrack" implements quantifier elimination over
  5050 special-purpose dense linear orders using locales (analogous to
  5051 "algebra"). The method is already installed for class
  5052 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  5053 rat, etc.
  5054 
  5055 * Former constant "List.op @" now named "List.append".  Use ML
  5056 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  5057 circumvent possible incompatibilities when working on ML level.
  5058 
  5059 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  5060 
  5061 * New function listsum :: 'a list => 'a for arbitrary monoids.
  5062 Special syntax: "SUM x <- xs. f x" (and latex variants)
  5063 
  5064 * New syntax for Haskell-like list comprehension (input only), eg.
  5065 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  5066 
  5067 * The special syntax for function "filter" has changed from [x :
  5068 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  5069 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  5070 
  5071 * [a..b] is now defined for arbitrary linear orders.  It used to be
  5072 defined on nat only, as an abbreviation for [a..<Suc b]
  5073 INCOMPATIBILITY.
  5074 
  5075 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  5076 
  5077 * New functions "sorted" and "sort" in src/HOL/List.thy.
  5078 
  5079 * New lemma collection field_simps (an extension of ring_simps) for
  5080 manipulating (in)equations involving division. Multiplies with all
  5081 denominators that can be proved to be non-zero (in equations) or
  5082 positive/negative (in inequations).
  5083 
  5084 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  5085 have been improved and renamed to ring_simps, group_simps and
  5086 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  5087 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  5088 
  5089 * Theory Library/Commutative_Ring: switched from recdef to function
  5090 package; constants add, mul, pow now curried.  Infix syntax for
  5091 algebraic operations.
  5092 
  5093 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  5094 INCOMPATIBILITY.
  5095 
  5096 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  5097 INCOMPATIBILITY.
  5098 
  5099 * HOL/records: generalised field-update to take a function on the
  5100 field rather than the new value: r(|A := x|) is translated to A_update
  5101 (K x) r The K-combinator that is internally used is called K_record.
  5102 INCOMPATIBILITY: Usage of the plain update functions has to be
  5103 adapted.
  5104  
  5105 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  5106 * x = 0, which are required for a semiring.  Richer structures do not
  5107 inherit from semiring_0 anymore, because this property is a theorem
  5108 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  5109 there is more to prove, but this is mostly trivial.
  5110 
  5111 * Class "recpower" is generalized to arbitrary monoids, not just
  5112 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  5113 commutativity or semiring properties additionally.
  5114 
  5115 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  5116 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  5117 better use 'abbreviation'.
  5118 
  5119 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  5120 
  5121 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  5122 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  5123 significant changes for setting up numeral syntax for types:
  5124   - New constants Numeral.pred and Numeral.succ instead
  5125       of former Numeral.bin_pred and Numeral.bin_succ.
  5126   - Use integer operations instead of bin_add, bin_mult and so on.
  5127   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  5128   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  5129 
  5130 See src/HOL/Integ/IntArith.thy for an example setup.
  5131 
  5132 * Command 'normal_form' computes the normal form of a term that may
  5133 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  5134 produces ``[b, c, a]'' (without proof).  This command is suitable for
  5135 heavy-duty computations because the functions are compiled to ML
  5136 first.  Correspondingly, a method "normalization" is provided.  See
  5137 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  5138 
  5139 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  5140 25 like -->); output depends on the "iff" print_mode, the default is
  5141 "A = B" (with priority 50).
  5142 
  5143 * Relations less (<) and less_eq (<=) are also available on type bool.
  5144 Modified syntax to disallow nesting without explicit parentheses,
  5145 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  5146 INCOMPATIBILITY.
  5147 
  5148 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  5149 
  5150 * Relation composition operator "op O" now has precedence 75 and binds
  5151 stronger than union and intersection. INCOMPATIBILITY.
  5152 
  5153 * The old set interval syntax "{m..n(}" (and relatives) has been
  5154 removed.  Use "{m..<n}" (and relatives) instead.
  5155 
  5156 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  5157 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  5158 ``declare [[simproc del: neq]]''.
  5159 
  5160 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  5161 True/False.
  5162 
  5163 * Theorem Cons_eq_map_conv no longer declared as "simp".
  5164 
  5165 * Theorem setsum_mult renamed to setsum_right_distrib.
  5166 
  5167 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  5168 ``rule'' method.
  5169 
  5170 * Reimplemented methods "sat" and "satx", with several improvements:
  5171 goals no longer need to be stated as "<prems> ==> False", equivalences
  5172 (i.e. "=" on type bool) are handled, variable names of the form
  5173 "lit_<n>" are no longer reserved, significant speedup.
  5174 
  5175 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  5176 zChaff is still supported as well.
  5177 
  5178 * 'inductive' and 'datatype': provide projections of mutual rules,
  5179 bundled as foo_bar.inducts;
  5180 
  5181 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  5182 Library.
  5183 
  5184 * Library: moved theory Accessible_Part to main HOL.
  5185 
  5186 * Library: added theory Coinductive_List of potentially infinite lists
  5187 as greatest fixed-point.
  5188 
  5189 * Library: added theory AssocList which implements (finite) maps as
  5190 association lists.
  5191 
  5192 * Method "evaluation" solves goals (i.e. a boolean expression)
  5193 efficiently by compiling it to ML.  The goal is "proved" (via an
  5194 oracle) if it evaluates to True.
  5195 
  5196 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  5197 also when invoked by the simplifier.  This results in the Simplifier
  5198 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  5199 Configuration option fast_arith_split_limit=0 recovers the old
  5200 behavior.
  5201 
  5202 * Support for hex (0x20) and binary (0b1001) numerals.
  5203 
  5204 * New method: reify eqs (t), where eqs are equations for an
  5205 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  5206 parameter, computes a term s::'b and a list xs::'a list and proves the
  5207 theorem I xs s = t. This is also known as reification or quoting. The
  5208 resulting theorem is applied to the subgoal to substitute t with I xs
  5209 s.  If t is omitted, the subgoal itself is reified.
  5210 
  5211 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  5212 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  5213 where f is supposed to be a computable function (in the sense of code
  5214 generattion). The method uses reify to compute s and xs as above then
  5215 applies corr_thm and uses normalization by evaluation to "prove" f s =
  5216 r and finally gets the theorem t = r, which is again applied to the
  5217 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  5218 
  5219 * Reflection: Automatic reification now handels binding, an example is
  5220 available in src/HOL/ex/ReflectionEx.thy
  5221 
  5222 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  5223 command 'statespace' that is similar to 'record', but introduces an
  5224 abstract specification based on the locale infrastructure instead of
  5225 HOL types.  This leads to extra flexibility in composing state spaces,
  5226 in particular multiple inheritance and renaming of components.
  5227 
  5228 
  5229 *** HOL-Complex ***
  5230 
  5231 * Hyperreal: Functions root and sqrt are now defined on negative real
  5232 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  5233 Nonnegativity side conditions have been removed from many lemmas, so
  5234 that more subgoals may now be solved by simplification; potential
  5235 INCOMPATIBILITY.
  5236 
  5237 * Real: new type classes formalize real normed vector spaces and
  5238 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  5239 and norm :: 'a => real.
  5240 
  5241 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  5242 reals into other types. The overloaded constant Reals :: 'a set is now
  5243 defined as range of_real; potential INCOMPATIBILITY.
  5244 
  5245 * Real: proper support for ML code generation, including 'quickcheck'.
  5246 Reals are implemented as arbitrary precision rationals.
  5247 
  5248 * Hyperreal: Several constants that previously worked only for the
  5249 reals have been generalized, so they now work over arbitrary vector
  5250 spaces. Type annotations may need to be added in some cases; potential
  5251 INCOMPATIBILITY.
  5252 
  5253   Infinitesimal  :: ('a::real_normed_vector) star set
  5254   HFinite        :: ('a::real_normed_vector) star set
  5255   HInfinite      :: ('a::real_normed_vector) star set
  5256   approx         :: ('a::real_normed_vector) star => 'a star => bool
  5257   monad          :: ('a::real_normed_vector) star => 'a star set
  5258   galaxy         :: ('a::real_normed_vector) star => 'a star set
  5259   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  5260   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  5261   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  5262   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  5263   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  5264   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  5265   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5266   sgn            :: 'a::real_normed_vector => 'a
  5267   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5268 
  5269 * Complex: Some complex-specific constants are now abbreviations for
  5270 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5271 hnorm.  Other constants have been entirely removed in favor of the
  5272 polymorphic versions (INCOMPATIBILITY):
  5273 
  5274   approx        <-- capprox
  5275   HFinite       <-- CFinite
  5276   HInfinite     <-- CInfinite
  5277   Infinitesimal <-- CInfinitesimal
  5278   monad         <-- cmonad
  5279   galaxy        <-- cgalaxy
  5280   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5281   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5282   (ns)deriv     <-- (ns)cderiv
  5283 
  5284 
  5285 *** HOL-Algebra ***
  5286 
  5287 * Formalisation of ideals and the quotient construction over rings.
  5288 
  5289 * Order and lattice theory no longer based on records.
  5290 INCOMPATIBILITY.
  5291 
  5292 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5293 greatest_closed.  INCOMPATIBILITY.
  5294 
  5295 * Method algebra is now set up via an attribute.  For examples see
  5296 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5297 of algebraic structures.
  5298 
  5299 * Renamed theory CRing to Ring.
  5300 
  5301 
  5302 *** HOL-Nominal ***
  5303 
  5304 * Substantial, yet incomplete support for nominal datatypes (binding
  5305 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5306 src/HOL/Nominal/Examples.  Prospective users should consult
  5307 http://isabelle.in.tum.de/nominal/
  5308 
  5309 
  5310 *** ML ***
  5311 
  5312 * ML basics: just one true type int, which coincides with IntInf.int
  5313 (even on SML/NJ).
  5314 
  5315 * ML within Isar: antiquotations allow to embed statically-checked
  5316 formal entities in the source, referring to the context available at
  5317 compile-time.  For example:
  5318 
  5319 ML {* @{sort "{zero,one}"} *}
  5320 ML {* @{typ "'a => 'b"} *}
  5321 ML {* @{term "%x. x"} *}
  5322 ML {* @{prop "x == y"} *}
  5323 ML {* @{ctyp "'a => 'b"} *}
  5324 ML {* @{cterm "%x. x"} *}
  5325 ML {* @{cprop "x == y"} *}
  5326 ML {* @{thm asm_rl} *}
  5327 ML {* @{thms asm_rl} *}
  5328 ML {* @{type_name c} *}
  5329 ML {* @{type_syntax c} *}
  5330 ML {* @{const_name c} *}
  5331 ML {* @{const_syntax c} *}
  5332 ML {* @{context} *}
  5333 ML {* @{theory} *}
  5334 ML {* @{theory Pure} *}
  5335 ML {* @{theory_ref} *}
  5336 ML {* @{theory_ref Pure} *}
  5337 ML {* @{simpset} *}
  5338 ML {* @{claset} *}
  5339 ML {* @{clasimpset} *}
  5340 
  5341 The same works for sources being ``used'' within an Isar context.
  5342 
  5343 * ML in Isar: improved error reporting; extra verbosity with
  5344 ML_Context.trace enabled.
  5345 
  5346 * Pure/General/table.ML: the join operations now works via exceptions
  5347 DUP/SAME instead of type option. This is simpler in simple cases, and
  5348 admits slightly more efficient complex applications.
  5349 
  5350 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5351 use Context.generic instead of just theory.
  5352 
  5353 * Pure: datatype Context.generic joins theory/Proof.context and
  5354 provides some facilities for code that works in either kind of
  5355 context, notably GenericDataFun for uniform theory and proof data.
  5356 
  5357 * Pure: simplified internal attribute type, which is now always
  5358 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5359 local (Proof.context) attributes have been discontinued, while
  5360 minimizing code duplication. Thm.rule_attribute and
  5361 Thm.declaration_attribute build canonical attributes; see also structure
  5362 Context for further operations on Context.generic, notably
  5363 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5364 declarations and definitions.
  5365 
  5366 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5367 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5368 init only required for impure data. INCOMPATIBILITY: empty really need
  5369 to be empty (no dependencies on theory content!)
  5370 
  5371 * Pure/kernel: consts certification ignores sort constraints given in
  5372 signature declarations. (This information is not relevant to the
  5373 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5374 potential INCOMPATIBILITY.
  5375 
  5376 * Pure: axiomatic type classes are now purely definitional, with
  5377 explicit proofs of class axioms and super class relations performed
  5378 internally. See Pure/axclass.ML for the main internal interfaces --
  5379 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5380 AxClass.axiomatize_class/classrel/arity supersede
  5381 Sign.add_classes/classrel/arities.
  5382 
  5383 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5384 global/local versions on theory vs. Proof.context have been
  5385 discontinued; Attrib.syntax and Method.syntax have been adapted
  5386 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5387 attributes, methods, etc.
  5388 
  5389 * Pure: several functions of signature "... -> theory -> theory * ..."
  5390 have been reoriented to "... -> theory -> ... * theory" in order to
  5391 allow natural usage in combination with the ||>, ||>>, |-> and
  5392 fold_map combinators.
  5393 
  5394 * Pure: official theorem names (closed derivations) and additional
  5395 comments (tags) are now strictly separate.  Name hints -- which are
  5396 maintained as tags -- may be attached any time without affecting the
  5397 derivation.
  5398 
  5399 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5400 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5401 achieve the old behaviour.
  5402 
  5403 * Pure: the "Goal" constant is now called "prop", supporting a
  5404 slightly more general idea of ``protecting'' meta-level rule
  5405 statements.
  5406 
  5407 * Pure: Logic.(un)varify only works in a global context, which is now
  5408 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5409 Logic.legacy_(un)varify as temporary workaround.
  5410 
  5411 * Pure: structure Name provides scalable operations for generating
  5412 internal variable names, notably Name.variants etc.  This replaces
  5413 some popular functions from term.ML:
  5414 
  5415   Term.variant		->  Name.variant
  5416   Term.variantlist	->  Name.variant_list
  5417   Term.invent_names	->  Name.invent_list
  5418 
  5419 Note that low-level renaming rarely occurs in new code -- operations
  5420 from structure Variable are used instead (see below).
  5421 
  5422 * Pure: structure Variable provides fundamental operations for proper
  5423 treatment of fixed/schematic variables in a context.  For example,
  5424 Variable.import introduces fixes for schematics of given facts and
  5425 Variable.export reverses the effect (up to renaming) -- this replaces
  5426 various freeze_thaw operations.
  5427 
  5428 * Pure: structure Goal provides simple interfaces for
  5429 init/conclude/finish and tactical prove operations (replacing former
  5430 Tactic.prove).  Goal.prove is the canonical way to prove results
  5431 within a given context; Goal.prove_global is a degraded version for
  5432 theory level goals, including a global Drule.standard.  Note that
  5433 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  5434 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  5435 in a locale context).
  5436 
  5437 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  5438 and type checking (Syntax.check_term etc.), with common combinations
  5439 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  5440 which are considered legacy and await removal.
  5441 
  5442 * Pure/Syntax: generic interfaces for type unchecking
  5443 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  5444 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  5445 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  5446 available for convenience, but refer to the very same operations using
  5447 a mere theory instead of a full context.
  5448 
  5449 * Isar: simplified treatment of user-level errors, using exception
  5450 ERROR of string uniformly.  Function error now merely raises ERROR,
  5451 without any side effect on output channels.  The Isar toplevel takes
  5452 care of proper display of ERROR exceptions.  ML code may use plain
  5453 handle/can/try; cat_error may be used to concatenate errors like this:
  5454 
  5455   ... handle ERROR msg => cat_error msg "..."
  5456 
  5457 Toplevel ML code (run directly or through the Isar toplevel) may be
  5458 embedded into the Isar toplevel with exception display/debug like
  5459 this:
  5460 
  5461   Isar.toplevel (fn () => ...)
  5462 
  5463 INCOMPATIBILITY, removed special transform_error facilities, removed
  5464 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  5465 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  5466 -- use plain ERROR instead.
  5467 
  5468 * Isar: theory setup now has type (theory -> theory), instead of a
  5469 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  5470 
  5471 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  5472 ProofContext.debug/verbose flags.
  5473 
  5474 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  5475 theory before entering a proof state.  Transactions now always see a
  5476 quasi-functional intermediate checkpoint, both in interactive and
  5477 batch mode.
  5478 
  5479 * Isar: simplified interfaces for outer syntax.  Renamed
  5480 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  5481 OuterSyntax.add_parsers -- this functionality is now included in
  5482 OuterSyntax.command etc.  INCOMPATIBILITY.
  5483 
  5484 * Simplifier: the simpset of a running simplification process now
  5485 contains a proof context (cf. Simplifier.the_context), which is the
  5486 very context that the initial simpset has been retrieved from (by
  5487 simpset_of/local_simpset_of).  Consequently, all plug-in components
  5488 (solver, looper etc.) may depend on arbitrary proof data.
  5489 
  5490 * Simplifier.inherit_context inherits the proof context (plus the
  5491 local bounds) of the current simplification process; any simproc
  5492 etc. that calls the Simplifier recursively should do this!  Removed
  5493 former Simplifier.inherit_bounds, which is already included here --
  5494 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  5495 specify an explicit context using Simplifier.context/theory_context.
  5496 
  5497 * Simplifier/Classical Reasoner: more abstract interfaces
  5498 change_simpset/claset for modifying the simpset/claset reference of a
  5499 theory; raw versions simpset/claset_ref etc. have been discontinued --
  5500 INCOMPATIBILITY.
  5501 
  5502 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  5503 "Trueprop" etc.
  5504 
  5505 
  5506 *** System ***
  5507 
  5508 * settings: the default heap location within ISABELLE_HOME_USER now
  5509 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  5510 Isabelle installations.
  5511 
  5512 * isabelle-process: option -S (secure mode) disables some critical
  5513 operations, notably runtime compilation and evaluation of ML source
  5514 code.
  5515 
  5516 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  5517 
  5518 * Support for parallel execution, using native multicore support of
  5519 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  5520 independent theories, according to the given theory header
  5521 specifications. The maximum number of worker threads is specified via
  5522 usedir option -M or the "max-threads" setting in Proof General. A
  5523 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  5524 to 6 on a 8-core machine.  User-code needs to observe certain
  5525 guidelines for thread-safe programming, see appendix A in the Isar
  5526 Implementation manual.
  5527 
  5528 
  5529 
  5530 New in Isabelle2005 (October 2005)
  5531 ----------------------------------
  5532 
  5533 *** General ***
  5534 
  5535 * Theory headers: the new header syntax for Isar theories is
  5536 
  5537   theory <name>
  5538   imports <theory1> ... <theoryN>
  5539   uses <file1> ... <fileM>
  5540   begin
  5541 
  5542 where the 'uses' part is optional.  The previous syntax
  5543 
  5544   theory <name> = <theory1> + ... + <theoryN>:
  5545 
  5546 will disappear in the next release.  Use isatool fixheaders to convert
  5547 existing theory files.  Note that there is no change in ancient
  5548 non-Isar theories now, but these will disappear soon.
  5549 
  5550 * Theory loader: parent theories can now also be referred to via
  5551 relative and absolute paths.
  5552 
  5553 * Command 'find_theorems' searches for a list of criteria instead of a
  5554 list of constants. Known criteria are: intro, elim, dest, name:string,
  5555 simp:term, and any term. Criteria can be preceded by '-' to select
  5556 theorems that do not match. Intro, elim, dest select theorems that
  5557 match the current goal, name:s selects theorems whose fully qualified
  5558 name contain s, and simp:term selects all simplification rules whose
  5559 lhs match term.  Any other term is interpreted as pattern and selects
  5560 all theorems matching the pattern. Available in ProofGeneral under
  5561 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  5562 
  5563   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  5564 
  5565 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  5566 matching the current goal as introduction rule and not having "HOL."
  5567 in their name (i.e. not being defined in theory HOL).
  5568 
  5569 * Command 'thms_containing' has been discontinued in favour of
  5570 'find_theorems'; INCOMPATIBILITY.
  5571 
  5572 * Communication with Proof General is now 8bit clean, which means that
  5573 Unicode text in UTF-8 encoding may be used within theory texts (both
  5574 formal and informal parts).  Cf. option -U of the Isabelle Proof
  5575 General interface.  Here are some simple examples (cf. src/HOL/ex):
  5576 
  5577   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  5578   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  5579 
  5580 * Improved efficiency of the Simplifier and, to a lesser degree, the
  5581 Classical Reasoner.  Typical big applications run around 2 times
  5582 faster.
  5583 
  5584 
  5585 *** Document preparation ***
  5586 
  5587 * Commands 'display_drafts' and 'print_drafts' perform simple output
  5588 of raw sources.  Only those symbols that do not require additional
  5589 LaTeX packages (depending on comments in isabellesym.sty) are
  5590 displayed properly, everything else is left verbatim.  isatool display
  5591 and isatool print are used as front ends (these are subject to the
  5592 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  5593 
  5594 * Command tags control specific markup of certain regions of text,
  5595 notably folding and hiding.  Predefined tags include "theory" (for
  5596 theory begin and end), "proof" for proof commands, and "ML" for
  5597 commands involving ML code; the additional tags "visible" and
  5598 "invisible" are unused by default.  Users may give explicit tag
  5599 specifications in the text, e.g. ''by %invisible (auto)''.  The
  5600 interpretation of tags is determined by the LaTeX job during document
  5601 preparation: see option -V of isatool usedir, or options -n and -t of
  5602 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  5603 \isadroptag.
  5604 
  5605 Several document versions may be produced at the same time via isatool
  5606 usedir (the generated index.html will link all of them).  Typical
  5607 specifications include ''-V document=theory,proof,ML'' to present
  5608 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  5609 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  5610 these parts without any formal replacement text.  The Isabelle site
  5611 default settings produce ''document'' and ''outline'' versions as
  5612 specified above.
  5613 
  5614 * Several new antiquotations:
  5615 
  5616   @{term_type term} prints a term with its type annotated;
  5617 
  5618   @{typeof term} prints the type of a term;
  5619 
  5620   @{const const} is the same as @{term const}, but checks that the
  5621   argument is a known logical constant;
  5622 
  5623   @{term_style style term} and @{thm_style style thm} print a term or
  5624   theorem applying a "style" to it
  5625 
  5626   @{ML text}
  5627 
  5628 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  5629 definitions, equations, inequations etc., 'concl' printing only the
  5630 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  5631 to print the specified premise.  TermStyle.add_style provides an ML
  5632 interface for introducing further styles.  See also the "LaTeX Sugar"
  5633 document practical applications.  The ML antiquotation prints
  5634 type-checked ML expressions verbatim.
  5635 
  5636 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  5637 and 'text' support optional locale specification '(in loc)', which
  5638 specifies the default context for interpreting antiquotations.  For
  5639 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  5640 
  5641 * Option 'locale=NAME' of antiquotations specifies an alternative
  5642 context interpreting the subsequent argument.  For example: @{thm
  5643 [locale=lattice] inf_assoc}.
  5644 
  5645 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  5646 a proof context.
  5647 
  5648 * Proper output of antiquotations for theory commands involving a
  5649 proof context (such as 'locale' or 'theorem (in loc) ...').
  5650 
  5651 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  5652 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  5653 
  5654 * isatool usedir: new option -C (default true) controls whether option
  5655 -D should include a copy of the original document directory; -C false
  5656 prevents unwanted effects such as copying of administrative CVS data.
  5657 
  5658 
  5659 *** Pure ***
  5660 
  5661 * Considerably improved version of 'constdefs' command.  Now performs
  5662 automatic type-inference of declared constants; additional support for
  5663 local structure declarations (cf. locales and HOL records), see also
  5664 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  5665 sequential dependencies of definitions within a single 'constdefs'
  5666 section; moreover, the declared name needs to be an identifier.  If
  5667 all fails, consider to fall back on 'consts' and 'defs' separately.
  5668 
  5669 * Improved indexed syntax and implicit structures.  First of all,
  5670 indexed syntax provides a notational device for subscripted
  5671 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  5672 expressions.  Secondly, in a local context with structure
  5673 declarations, number indexes \<^sub>n or the empty index (default
  5674 number 1) refer to a certain fixed variable implicitly; option
  5675 show_structs controls printing of implicit structures.  Typical
  5676 applications of these concepts involve record types and locales.
  5677 
  5678 * New command 'no_syntax' removes grammar declarations (and
  5679 translations) resulting from the given syntax specification, which is
  5680 interpreted in the same manner as for the 'syntax' command.
  5681 
  5682 * 'Advanced' translation functions (parse_translation etc.) may depend
  5683 on the signature of the theory context being presently used for
  5684 parsing/printing, see also isar-ref manual.
  5685 
  5686 * Improved 'oracle' command provides a type-safe interface to turn an
  5687 ML expression of type theory -> T -> term into a primitive rule of
  5688 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  5689 is already included here); see also FOL/ex/IffExample.thy;
  5690 INCOMPATIBILITY.
  5691 
  5692 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  5693 before); "cI" is no longer bound, use "c.intro" instead.
  5694 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  5695 axclasses vs. locales.
  5696 
  5697 * Improved internal renaming of symbolic identifiers -- attach primes
  5698 instead of base 26 numbers.
  5699 
  5700 * New flag show_question_marks controls printing of leading question
  5701 marks in schematic variable names.
  5702 
  5703 * In schematic variable names, *any* symbol following \<^isub> or
  5704 \<^isup> is now treated as part of the base name.  For example, the
  5705 following works without printing of awkward ".0" indexes:
  5706 
  5707   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  5708     by simp
  5709 
  5710 * Inner syntax includes (*(*nested*) comments*).
  5711 
  5712 * Pretty printer now supports unbreakable blocks, specified in mixfix
  5713 annotations as "(00...)".
  5714 
  5715 * Clear separation of logical types and nonterminals, where the latter
  5716 may only occur in 'syntax' specifications or type abbreviations.
  5717 Before that distinction was only partially implemented via type class
  5718 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  5719 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  5720 exotic syntax specifications may require further adaption
  5721 (e.g. Cube/Cube.thy).
  5722 
  5723 * Removed obsolete type class "logic", use the top sort {} instead.
  5724 Note that non-logical types should be declared as 'nonterminals'
  5725 rather than 'types'.  INCOMPATIBILITY for new object-logic
  5726 specifications.
  5727 
  5728 * Attributes 'induct' and 'cases': type or set names may now be
  5729 locally fixed variables as well.
  5730 
  5731 * Simplifier: can now control the depth to which conditional rewriting
  5732 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  5733 Limit.
  5734 
  5735 * Simplifier: simplification procedures may now take the current
  5736 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  5737 interface), which is very useful for calling the Simplifier
  5738 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  5739 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  5740 low-level mk_simproc no longer applies Logic.varify internally, to
  5741 allow for use in a context of fixed variables.
  5742 
  5743 * thin_tac now works even if the assumption being deleted contains !!
  5744 or ==>.  More generally, erule now works even if the major premise of
  5745 the elimination rule contains !! or ==>.
  5746 
  5747 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  5748 
  5749 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  5750 from Pure, which contains all common declarations already.  Both
  5751 theories are defined via plain Isabelle/Isar .thy files.
  5752 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  5753 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  5754 use isatool fixcpure to adapt your theory and ML sources.
  5755 
  5756 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  5757 selections of theorems in named facts via index ranges.
  5758 
  5759 * 'print_theorems': in theory mode, really print the difference
  5760 wrt. the last state (works for interactive theory development only),
  5761 in proof mode print all local facts (cf. 'print_facts');
  5762 
  5763 * 'hide': option '(open)' hides only base names.
  5764 
  5765 * More efficient treatment of intermediate checkpoints in interactive
  5766 theory development.
  5767 
  5768 * Code generator is now invoked via code_module (incremental code
  5769 generation) and code_library (modular code generation, ML structures
  5770 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  5771 must be quoted when used as identifiers.
  5772 
  5773 * New 'value' command for reading, evaluating and printing terms using
  5774 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  5775 quoted when used as identifier.
  5776 
  5777 
  5778 *** Locales ***
  5779 
  5780 * New commands for the interpretation of locale expressions in
  5781 theories (1), locales (2) and proof contexts (3).  These generate
  5782 proof obligations from the expression specification.  After the
  5783 obligations have been discharged, theorems of the expression are added
  5784 to the theory, target locale or proof context.  The synopsis of the
  5785 commands is a follows:
  5786 
  5787   (1) interpretation expr inst
  5788   (2) interpretation target < expr
  5789   (3) interpret expr inst
  5790 
  5791 Interpretation in theories and proof contexts require a parameter
  5792 instantiation of terms from the current context.  This is applied to
  5793 specifications and theorems of the interpreted expression.
  5794 Interpretation in locales only permits parameter renaming through the
  5795 locale expression.  Interpretation is smart in that interpretations
  5796 that are active already do not occur in proof obligations, neither are
  5797 instantiated theorems stored in duplicate.  Use 'print_interps' to
  5798 inspect active interpretations of a particular locale.  For details,
  5799 see the Isar Reference manual.  Examples can be found in
  5800 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  5801 
  5802 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  5803 'interpret' instead.
  5804 
  5805 * New context element 'constrains' for adding type constraints to
  5806 parameters.
  5807 
  5808 * Context expressions: renaming of parameters with syntax
  5809 redeclaration.
  5810 
  5811 * Locale declaration: 'includes' disallowed.
  5812 
  5813 * Proper static binding of attribute syntax -- i.e. types / terms /
  5814 facts mentioned as arguments are always those of the locale definition
  5815 context, independently of the context of later invocations.  Moreover,
  5816 locale operations (renaming and type / term instantiation) are applied
  5817 to attribute arguments as expected.
  5818 
  5819 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5820 actual attributes; rare situations may require Attrib.attribute to
  5821 embed those attributes into Attrib.src that lack concrete syntax.
  5822 Attribute implementations need to cooperate properly with the static
  5823 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5824 Attrib.XXX_thm etc. already do the right thing without further
  5825 intervention.  Only unusual applications -- such as "where" or "of"
  5826 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5827 on the context and the facts involved -- may have to assign parsed
  5828 values to argument tokens explicitly.
  5829 
  5830 * Changed parameter management in theorem generation for long goal
  5831 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5832 theorem statement in rare situations.
  5833 
  5834 * Locale inspection command 'print_locale' omits notes elements.  Use
  5835 'print_locale!' to have them included in the output.
  5836 
  5837 
  5838 *** Provers ***
  5839 
  5840 * Provers/hypsubst.ML: improved version of the subst method, for
  5841 single-step rewriting: it now works in bound variable contexts. New is
  5842 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5843 rewrite a different subterm than the original subst method, which is
  5844 still available as 'simplesubst'.
  5845 
  5846 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5847 and quasi orders.
  5848 
  5849 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5850 reflexive-transitive closure of relations.
  5851 
  5852 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5853 limit (previously hard-coded with a value of 20) user-definable.
  5854 
  5855 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5856 is peformed already.  Object-logics merely need to finish their
  5857 initial simpset configuration as before.  INCOMPATIBILITY.
  5858 
  5859 
  5860 *** HOL ***
  5861 
  5862 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5863 
  5864   syntax (epsilon)
  5865     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5866 
  5867 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5868 and x-symbol; use option '-m epsilon' to get it actually printed.
  5869 Moreover, the mathematically important symbolic identifier \<epsilon>
  5870 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5871 
  5872 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5873 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5874 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5875 support corresponding Isar calculations.
  5876 
  5877 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5878 instead of ":".
  5879 
  5880 * theory SetInterval: changed the syntax for open intervals:
  5881 
  5882   Old       New
  5883   {..n(}    {..<n}
  5884   {)n..}    {n<..}
  5885   {m..n(}   {m..<n}
  5886   {)m..n}   {m<..n}
  5887   {)m..n(}  {m<..<n}
  5888 
  5889 The old syntax is still supported but will disappear in the next
  5890 release.  For conversion use the following Emacs search and replace
  5891 patterns (these are not perfect but work quite well):
  5892 
  5893   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5894   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5895 
  5896 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5897 equalities in commutative rings; method 'algebra' provides a generic
  5898 interface.
  5899 
  5900 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5901 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5902 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5903 be a tuple pattern.
  5904 
  5905 Some new syntax forms are available:
  5906 
  5907   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5908   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5909   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5910   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5911 
  5912 The latter form "\<Sum>x < k. e" used to be based on a separate
  5913 function "Summation", which has been discontinued.
  5914 
  5915 * theory Finite_Set: in structured induction proofs, the insert case
  5916 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5917 (insert F x)'.
  5918 
  5919 * The 'refute' command has been extended to support a much larger
  5920 fragment of HOL, including axiomatic type classes, constdefs and
  5921 typedefs, inductive datatypes and recursion.
  5922 
  5923 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5924 Requires zChaff with proof generation to be installed.  See
  5925 HOL/ex/SAT_Examples.thy for examples.
  5926 
  5927 * Datatype induction via method 'induct' now preserves the name of the
  5928 induction variable. For example, when proving P(xs::'a list) by
  5929 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5930 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5931 in unstructured proof scripts.
  5932 
  5933 * Reworked implementation of records.  Improved scalability for
  5934 records with many fields, avoiding performance problems for type
  5935 inference. Records are no longer composed of nested field types, but
  5936 of nested extension types. Therefore the record type only grows linear
  5937 in the number of extensions and not in the number of fields.  The
  5938 top-level (users) view on records is preserved.  Potential
  5939 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5940 old record representation. The type generated for a record is called
  5941 <record_name>_ext_type.
  5942 
  5943 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5944 proofs triggered by a record definition or a simproc (if
  5945 quick_and_dirty is enabled).  Definitions of large records can take
  5946 quite long.
  5947 
  5948 New simproc record_upd_simproc for simplification of multiple record
  5949 updates enabled by default.  Moreover, trivial updates are also
  5950 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5951 occasionally, since simplification is more powerful by default.
  5952 
  5953 * typedef: proper support for polymorphic sets, which contain extra
  5954 type-variables in the term.
  5955 
  5956 * Simplifier: automatically reasons about transitivity chains
  5957 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5958 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5959 old proofs break occasionally as simplification may now solve more
  5960 goals than previously.
  5961 
  5962 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5963 present.  Works for all partial orders (class "order"), in particular
  5964 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5965 just like y <= x.
  5966 
  5967 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5968 bound variable or a constant then the let is unfolded.  Otherwise
  5969 first a is simplified to b, and then f b is simplified to g. If
  5970 possible we abstract b from g arriving at "let x = b in h x",
  5971 otherwise we unfold the let and arrive at g.  The simproc can be
  5972 enabled/disabled by the reference use_let_simproc.  Potential
  5973 INCOMPATIBILITY since simplification is more powerful by default.
  5974 
  5975 * Classical reasoning: the meson method now accepts theorems as arguments.
  5976 
  5977 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5978 jobs to provide advice on the provability of subgoals.
  5979 
  5980 * Theory OrderedGroup and Ring_and_Field: various additions and
  5981 improvements to faciliate calculations involving equalities and
  5982 inequalities.
  5983 
  5984 The following theorems have been eliminated or modified
  5985 (INCOMPATIBILITY):
  5986 
  5987   abs_eq             now named abs_of_nonneg
  5988   abs_of_ge_0        now named abs_of_nonneg
  5989   abs_minus_eq       now named abs_of_nonpos
  5990   imp_abs_id         now named abs_of_nonneg
  5991   imp_abs_neg_id     now named abs_of_nonpos
  5992   mult_pos           now named mult_pos_pos
  5993   mult_pos_le        now named mult_nonneg_nonneg
  5994   mult_pos_neg_le    now named mult_nonneg_nonpos
  5995   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5996   mult_neg           now named mult_neg_neg
  5997   mult_neg_le        now named mult_nonpos_nonpos
  5998 
  5999 * The following lemmas in Ring_and_Field have been added to the simplifier:
  6000      
  6001      zero_le_square
  6002      not_square_less_zero 
  6003 
  6004   The following lemmas have been deleted from Real/RealPow:
  6005   
  6006      realpow_zero_zero
  6007      realpow_two
  6008      realpow_less
  6009      zero_le_power
  6010      realpow_two_le
  6011      abs_realpow_two
  6012      realpow_two_abs     
  6013 
  6014 * Theory Parity: added rules for simplifying exponents.
  6015 
  6016 * Theory List:
  6017 
  6018 The following theorems have been eliminated or modified
  6019 (INCOMPATIBILITY):
  6020 
  6021   list_all_Nil       now named list_all.simps(1)
  6022   list_all_Cons      now named list_all.simps(2)
  6023   list_all_conv      now named list_all_iff
  6024   set_mem_eq         now named mem_iff
  6025 
  6026 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  6027 asymptotic "big O" calculations.  See the notes in BigO.thy.
  6028 
  6029 
  6030 *** HOL-Complex ***
  6031 
  6032 * Theory RealDef: better support for embedding natural numbers and
  6033 integers in the reals.
  6034 
  6035 The following theorems have been eliminated or modified
  6036 (INCOMPATIBILITY):
  6037 
  6038   exp_ge_add_one_self  now requires no hypotheses
  6039   real_of_int_add      reversed direction of equality (use [symmetric])
  6040   real_of_int_minus    reversed direction of equality (use [symmetric])
  6041   real_of_int_diff     reversed direction of equality (use [symmetric])
  6042   real_of_int_mult     reversed direction of equality (use [symmetric])
  6043 
  6044 * Theory RComplete: expanded support for floor and ceiling functions.
  6045 
  6046 * Theory Ln is new, with properties of the natural logarithm
  6047 
  6048 * Hyperreal: There is a new type constructor "star" for making
  6049 nonstandard types.  The old type names are now type synonyms:
  6050 
  6051   hypreal = real star
  6052   hypnat = nat star
  6053   hcomplex = complex star
  6054 
  6055 * Hyperreal: Many groups of similarly-defined constants have been
  6056 replaced by polymorphic versions (INCOMPATIBILITY):
  6057 
  6058   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  6059 
  6060   starset      <-- starsetNat, starsetC
  6061   *s*          <-- *sNat*, *sc*
  6062   starset_n    <-- starsetNat_n, starsetC_n
  6063   *sn*         <-- *sNatn*, *scn*
  6064   InternalSets <-- InternalNatSets, InternalCSets
  6065 
  6066   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  6067   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  6068   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  6069   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  6070   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  6071 
  6072 * Hyperreal: Many type-specific theorems have been removed in favor of
  6073 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  6074 
  6075   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  6076   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  6077   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  6078   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  6079   right_minus <-- hypreal_add_minus
  6080   left_minus <-- {hypreal,hcomplex}_add_minus_left
  6081   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  6082   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  6083   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  6084   mult_1_right <-- hcomplex_mult_one_right
  6085   mult_zero_left <-- hcomplex_mult_zero_left
  6086   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  6087   right_distrib <-- hypnat_add_mult_distrib2
  6088   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  6089   right_inverse <-- hypreal_mult_inverse
  6090   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  6091   order_refl <-- {hypreal,hypnat}_le_refl
  6092   order_trans <-- {hypreal,hypnat}_le_trans
  6093   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  6094   order_less_le <-- {hypreal,hypnat}_less_le
  6095   linorder_linear <-- {hypreal,hypnat}_le_linear
  6096   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  6097   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  6098   add_nonneg_nonneg <-- hypreal_le_add_order
  6099 
  6100 * Hyperreal: Separate theorems having to do with type-specific
  6101 versions of constants have been merged into theorems that apply to the
  6102 new polymorphic constants (INCOMPATIBILITY):
  6103 
  6104   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  6105   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  6106   STAR_Un <-- {STAR,NatStar,STARC}_Un
  6107   STAR_Int <-- {STAR,NatStar,STARC}_Int
  6108   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  6109   STAR_subset <-- {STAR,NatStar,STARC}_subset
  6110   STAR_mem <-- {STAR,NatStar,STARC}_mem
  6111   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  6112   STAR_diff <-- {STAR,STARC}_diff
  6113   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  6114     STARC_hcomplex_of_complex}_image_subset
  6115   starset_n_Un <-- starset{Nat,C}_n_Un
  6116   starset_n_Int <-- starset{Nat,C}_n_Int
  6117   starset_n_Compl <-- starset{Nat,C}_n_Compl
  6118   starset_n_diff <-- starset{Nat,C}_n_diff
  6119   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  6120   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  6121   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  6122   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  6123   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  6124   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  6125   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  6126   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  6127   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  6128   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  6129   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  6130   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  6131   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  6132   starfun_diff <-- starfun{C,RC,CR}_diff
  6133   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  6134   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  6135   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  6136   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  6137   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  6138   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  6139   starfun_Id <-- starfunC_Id
  6140   starfun_approx <-- starfun{Nat,CR}_approx
  6141   starfun_capprox <-- starfun{C,RC}_capprox
  6142   starfun_abs <-- starfunNat_rabs
  6143   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  6144   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  6145   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  6146   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  6147   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  6148   starfun_add_approx <-- starfunCR_add_approx
  6149   starfun_inverse_inverse <-- starfunC_inverse_inverse
  6150   starfun_divide <-- starfun{C,CR,RC}_divide
  6151   starfun_n <-- starfun{Nat,C}_n
  6152   starfun_n_mult <-- starfun{Nat,C}_n_mult
  6153   starfun_n_add <-- starfun{Nat,C}_n_add
  6154   starfun_n_add_minus <-- starfunNat_n_add_minus
  6155   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  6156   starfun_n_minus <-- starfun{Nat,C}_n_minus
  6157   starfun_n_eq <-- starfun{Nat,C}_n_eq
  6158 
  6159   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  6160   star_n_minus <-- {hypreal,hcomplex}_minus
  6161   star_n_diff <-- {hypreal,hcomplex}_diff
  6162   star_n_mult <-- {hypreal,hcomplex}_mult
  6163   star_n_inverse <-- {hypreal,hcomplex}_inverse
  6164   star_n_le <-- {hypreal,hypnat}_le
  6165   star_n_less <-- {hypreal,hypnat}_less
  6166   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  6167   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  6168   star_n_abs <-- hypreal_hrabs
  6169   star_n_divide <-- hcomplex_divide
  6170 
  6171   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  6172   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  6173   star_of_diff <-- hypreal_of_real_diff
  6174   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  6175   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  6176   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  6177   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  6178   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  6179   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  6180   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  6181   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  6182   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  6183   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  6184   star_of_number_of <-- {hypreal,hcomplex}_number_of
  6185   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  6186   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  6187   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  6188   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  6189   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  6190   star_of_power <-- hypreal_of_real_power
  6191   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  6192 
  6193 * Hyperreal: new method "transfer" that implements the transfer
  6194 principle of nonstandard analysis. With a subgoal that mentions
  6195 nonstandard types like "'a star", the command "apply transfer"
  6196 replaces it with an equivalent one that mentions only standard types.
  6197 To be successful, all free variables must have standard types; non-
  6198 standard variables must have explicit universal quantifiers.
  6199 
  6200 * Hyperreal: A theory of Taylor series.
  6201 
  6202 
  6203 *** HOLCF ***
  6204 
  6205 * Discontinued special version of 'constdefs' (which used to support
  6206 continuous functions) in favor of the general Pure one with full
  6207 type-inference.
  6208 
  6209 * New simplification procedure for solving continuity conditions; it
  6210 is much faster on terms with many nested lambda abstractions (cubic
  6211 instead of exponential time).
  6212 
  6213 * New syntax for domain package: selector names are now optional.
  6214 Parentheses should be omitted unless argument is lazy, for example:
  6215 
  6216   domain 'a stream = cons "'a" (lazy "'a stream")
  6217 
  6218 * New command 'fixrec' for defining recursive functions with pattern
  6219 matching; defining multiple functions with mutual recursion is also
  6220 supported.  Patterns may include the constants cpair, spair, up, sinl,
  6221 sinr, or any data constructor defined by the domain package. The given
  6222 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  6223 syntax and examples.
  6224 
  6225 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  6226 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  6227 but the proof obligation additionally includes an admissibility
  6228 requirement. The packages generate instances of class cpo or pcpo,
  6229 with continuity and strictness theorems for Rep and Abs.
  6230 
  6231 * HOLCF: Many theorems have been renamed according to a more standard naming
  6232 scheme (INCOMPATIBILITY):
  6233 
  6234   foo_inject:  "foo$x = foo$y ==> x = y"
  6235   foo_eq:      "(foo$x = foo$y) = (x = y)"
  6236   foo_less:    "(foo$x << foo$y) = (x << y)"
  6237   foo_strict:  "foo$UU = UU"
  6238   foo_defined: "... ==> foo$x ~= UU"
  6239   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  6240 
  6241 
  6242 *** ZF ***
  6243 
  6244 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  6245 including the First Isomorphism Theorem (on quotienting by the kernel
  6246 of a homomorphism).
  6247 
  6248 * ZF/Simplifier: install second copy of type solver that actually
  6249 makes use of TC rules declared to Isar proof contexts (or locales);
  6250 the old version is still required for ML proof scripts.
  6251 
  6252 
  6253 *** Cube ***
  6254 
  6255 * Converted to Isar theory format; use locales instead of axiomatic
  6256 theories.
  6257 
  6258 
  6259 *** ML ***
  6260 
  6261 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  6262 for ||>, ||>>, |>>,
  6263 
  6264 * Pure/library.ML no longer defines its own option datatype, but uses
  6265 that of the SML basis, which has constructors NONE and SOME instead of
  6266 None and Some, as well as exception Option.Option instead of OPTION.
  6267 The functions the, if_none, is_some, is_none have been adapted
  6268 accordingly, while Option.map replaces apsome.
  6269 
  6270 * Pure/library.ML: the exception LIST has been given up in favour of
  6271 the standard exceptions Empty and Subscript, as well as
  6272 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6273 superceded by the standard hd and tl functions etc.
  6274 
  6275 A number of basic list functions are no longer exported to the ML
  6276 toplevel, as they are variants of predefined functions.  The following
  6277 suggests how one can translate existing code:
  6278 
  6279     rev_append xs ys = List.revAppend (xs, ys)
  6280     nth_elem (i, xs) = List.nth (xs, i)
  6281     last_elem xs = List.last xs
  6282     flat xss = List.concat xss
  6283     seq fs = List.app fs
  6284     partition P xs = List.partition P xs
  6285     mapfilter f xs = List.mapPartial f xs
  6286 
  6287 * Pure/library.ML: several combinators for linear functional
  6288 transformations, notably reverse application and composition:
  6289 
  6290   x |> f                f #> g
  6291   (x, y) |-> f          f #-> g
  6292 
  6293 * Pure/library.ML: introduced/changed precedence of infix operators:
  6294 
  6295   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6296   infix 2 ?;
  6297   infix 3 o oo ooo oooo;
  6298   infix 4 ~~ upto downto;
  6299 
  6300 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6301 infix operators.
  6302 
  6303 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6304 fold_map support linear functional transformations and nesting.  For
  6305 example:
  6306 
  6307   fold f [x1, ..., xN] y =
  6308     y |> f x1 |> ... |> f xN
  6309 
  6310   (fold o fold) f [xs1, ..., xsN] y =
  6311     y |> fold f xs1 |> ... |> fold f xsN
  6312 
  6313   fold f [x1, ..., xN] =
  6314     f x1 #> ... #> f xN
  6315 
  6316   (fold o fold) f [xs1, ..., xsN] =
  6317     fold f xs1 #> ... #> fold f xsN
  6318 
  6319 * Pure/library.ML: the following selectors on type 'a option are
  6320 available:
  6321 
  6322   the:               'a option -> 'a  (*partial*)
  6323   these:             'a option -> 'a  where 'a = 'b list
  6324   the_default: 'a -> 'a option -> 'a
  6325   the_list:          'a option -> 'a list
  6326 
  6327 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6328 basic operations for association lists, following natural argument
  6329 order; moreover the explicit equality predicate passed here avoids
  6330 potentially expensive polymorphic runtime equality checks.
  6331 The old functions may be expressed as follows:
  6332 
  6333   assoc = uncurry (AList.lookup (op =))
  6334   assocs = these oo AList.lookup (op =)
  6335   overwrite = uncurry (AList.update (op =)) o swap
  6336 
  6337 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6338 
  6339   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6340   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6341 
  6342 replacing make_keylist and keyfilter (occassionally used)
  6343 Naive rewrites:
  6344 
  6345   make_keylist = AList.make
  6346   keyfilter = AList.find (op =)
  6347 
  6348 * eq_fst and eq_snd now take explicit equality parameter, thus
  6349   avoiding eqtypes. Naive rewrites:
  6350 
  6351     eq_fst = eq_fst (op =)
  6352     eq_snd = eq_snd (op =)
  6353 
  6354 * Removed deprecated apl and apr (rarely used).
  6355   Naive rewrites:
  6356 
  6357     apl (n, op) =>>= curry op n
  6358     apr (op, m) =>>= fn n => op (n, m)
  6359 
  6360 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6361 provides a reasonably efficient light-weight implementation of sets as
  6362 lists.
  6363 
  6364 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6365 few new operations; existing lookup and update are now curried to
  6366 follow natural argument order (for use with fold etc.);
  6367 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6368 
  6369 * Pure/General: output via the Isabelle channels of
  6370 writeln/warning/error etc. is now passed through Output.output, with a
  6371 hook for arbitrary transformations depending on the print_mode
  6372 (cf. Output.add_mode -- the first active mode that provides a output
  6373 function wins).  Already formatted output may be embedded into further
  6374 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6375 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6376 accommodate easy composition of diagnostic messages etc.  Programmers
  6377 rarely need to care about Output.output or Output.raw at all, with
  6378 some notable exceptions: Output.output is required when bypassing the
  6379 standard channels (writeln etc.), or in token translations to produce
  6380 properly formatted results; Output.raw is required when capturing
  6381 already output material that will eventually be presented to the user
  6382 a second time.  For the default print mode, both Output.output and
  6383 Output.raw have no effect.
  6384 
  6385 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6386 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6387 cumulative results are displayed at the end of a batch session.
  6388 
  6389 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6390 replaced by File.platform_path and File.shell_path (with appropriate
  6391 hooks).  This provides a clean interface for unusual systems where the
  6392 internal and external process view of file names are different.
  6393 
  6394 * Pure: more efficient orders for basic syntactic entities: added
  6395 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6396 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6397 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6398 orders now -- potential INCOMPATIBILITY for code that depends on a
  6399 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6400 Library.sort_strings on result).
  6401 
  6402 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6403 fold_types traverse types/terms from left to right, observing natural
  6404 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6405 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6406 
  6407 * Pure: name spaces have been refined, with significant changes of the
  6408 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6409 to extern(_table).  The plain name entry path is superceded by a
  6410 general 'naming' context, which also includes the 'policy' to produce
  6411 a fully qualified name and external accesses of a fully qualified
  6412 name; NameSpace.extend is superceded by context dependent
  6413 Sign.declare_name.  Several theory and proof context operations modify
  6414 the naming context.  Especially note Theory.restore_naming and
  6415 ProofContext.restore_naming to get back to a sane state; note that
  6416 Theory.add_path is no longer sufficient to recover from
  6417 Theory.absolute_path in particular.
  6418 
  6419 * Pure: new flags short_names (default false) and unique_names
  6420 (default true) for controlling output of qualified names.  If
  6421 short_names is set, names are printed unqualified.  If unique_names is
  6422 reset, the name prefix is reduced to the minimum required to achieve
  6423 the original result when interning again, even if there is an overlap
  6424 with earlier declarations.
  6425 
  6426 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  6427 now 'extend', and 'merge' gets an additional Pretty.pp argument
  6428 (useful for printing error messages).  INCOMPATIBILITY.
  6429 
  6430 * Pure: major reorganization of the theory context.  Type Sign.sg and
  6431 Theory.theory are now identified, referring to the universal
  6432 Context.theory (see Pure/context.ML).  Actual signature and theory
  6433 content is managed as theory data.  The old code and interfaces were
  6434 spread over many files and structures; the new arrangement introduces
  6435 considerable INCOMPATIBILITY to gain more clarity:
  6436 
  6437   Context -- theory management operations (name, identity, inclusion,
  6438     parents, ancestors, merge, etc.), plus generic theory data;
  6439 
  6440   Sign -- logical signature and syntax operations (declaring consts,
  6441     types, etc.), plus certify/read for common entities;
  6442 
  6443   Theory -- logical theory operations (stating axioms, definitions,
  6444     oracles), plus a copy of logical signature operations (consts,
  6445     types, etc.); also a few basic management operations (Theory.copy,
  6446     Theory.merge, etc.)
  6447 
  6448 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  6449 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  6450 for convenience -- they merely return the theory.
  6451 
  6452 * Pure: type Type.tsig is superceded by theory in most interfaces.
  6453 
  6454 * Pure: the Isar proof context type is already defined early in Pure
  6455 as Context.proof (note that ProofContext.context and Proof.context are
  6456 aliases, where the latter is the preferred name).  This enables other
  6457 Isabelle components to refer to that type even before Isar is present.
  6458 
  6459 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  6460 typeK, constK, axiomK, oracleK), but provide explicit operations for
  6461 any of these kinds.  For example, Sign.intern typeK is now
  6462 Sign.intern_type, Theory.hide_space Sign.typeK is now
  6463 Theory.hide_types.  Also note that former
  6464 Theory.hide_classes/types/consts are now
  6465 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  6466 internalize their arguments!  INCOMPATIBILITY.
  6467 
  6468 * Pure: get_thm interface (of PureThy and ProofContext) expects
  6469 datatype thmref (with constructors Name and NameSelection) instead of
  6470 plain string -- INCOMPATIBILITY;
  6471 
  6472 * Pure: cases produced by proof methods specify options, where NONE
  6473 means to remove case bindings -- INCOMPATIBILITY in
  6474 (RAW_)METHOD_CASES.
  6475 
  6476 * Pure: the following operations retrieve axioms or theorems from a
  6477 theory node or theory hierarchy, respectively:
  6478 
  6479   Theory.axioms_of: theory -> (string * term) list
  6480   Theory.all_axioms_of: theory -> (string * term) list
  6481   PureThy.thms_of: theory -> (string * thm) list
  6482   PureThy.all_thms_of: theory -> (string * thm) list
  6483 
  6484 * Pure: print_tac now outputs the goal through the trace channel.
  6485 
  6486 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  6487 Reference Toplevel.debug (default false) controls detailed printing
  6488 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  6489 controls execution profiling -- set to 1 for time and 2 for space
  6490 (both increase the runtime).
  6491 
  6492 * Isar session: The initial use of ROOT.ML is now always timed,
  6493 i.e. the log will show the actual process times, in contrast to the
  6494 elapsed wall-clock time that the outer shell wrapper produces.
  6495 
  6496 * Simplifier: improved handling of bound variables (nameless
  6497 representation, avoid allocating new strings).  Simprocs that invoke
  6498 the Simplifier recursively should use Simplifier.inherit_bounds to
  6499 avoid local name clashes.  Failure to do so produces warnings
  6500 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  6501 for further details.
  6502 
  6503 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  6504 bindings for all theorems stored within a given theory; this may help
  6505 in porting non-Isar theories to Isar ones, while keeping ML proof
  6506 scripts for the time being.
  6507 
  6508 * ML operator HTML.with_charset specifies the charset begin used for
  6509 generated HTML files.  For example:
  6510 
  6511   HTML.with_charset "utf-8" use_thy "Hebrew";
  6512   HTML.with_charset "utf-8" use_thy "Chinese";
  6513 
  6514 
  6515 *** System ***
  6516 
  6517 * Allow symlinks to all proper Isabelle executables (Isabelle,
  6518 isabelle, isatool etc.).
  6519 
  6520 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  6521 isatool doc, isatool mkdir, display_drafts etc.).
  6522 
  6523 * isatool usedir: option -f allows specification of the ML file to be
  6524 used by Isabelle; default is ROOT.ML.
  6525 
  6526 * New isatool version outputs the version identifier of the Isabelle
  6527 distribution being used.
  6528 
  6529 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  6530 (containing Boolean satisfiability problems) into Isabelle/HOL
  6531 theories.
  6532 
  6533 
  6534 
  6535 New in Isabelle2004 (April 2004)
  6536 --------------------------------
  6537 
  6538 *** General ***
  6539 
  6540 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  6541   Replaces linorder.ML.
  6542 
  6543 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  6544   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  6545   (\<a>...\<z>), are now considered normal letters, and can therefore
  6546   be used anywhere where an ASCII letter (a...zA...Z) has until
  6547   now. COMPATIBILITY: This obviously changes the parsing of some
  6548   terms, especially where a symbol has been used as a binder, say
  6549   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  6550   as an identifier.  Fix it by inserting a space around former
  6551   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  6552   existing theory and ML files.
  6553 
  6554 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  6555 
  6556 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  6557   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  6558   a normal (but invisible) letter. For multiple letter subscripts repeat
  6559   \<^isub> like this: x\<^isub>1\<^isub>2.
  6560 
  6561 * Pure: There are now sub-/superscripts that can span more than one
  6562   character. Text between \<^bsub> and \<^esub> is set in subscript in
  6563   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  6564   superscript. The new control characters are not identifier parts.
  6565 
  6566 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  6567   content of "..." to the latex file instead of \isacntrl... . The "..."
  6568   may consist of any printable characters excluding the end bracket >.
  6569 
  6570 * Pure: Using new Isar command "finalconsts" (or the ML functions
  6571   Theory.add_finals or Theory.add_finals_i) it is now possible to
  6572   declare constants "final", which prevents their being given a definition
  6573   later.  It is useful for constants whose behaviour is fixed axiomatically
  6574   rather than definitionally, such as the meta-logic connectives.
  6575 
  6576 * Pure: 'instance' now handles general arities with general sorts
  6577   (i.e. intersections of classes),
  6578 
  6579 * Presentation: generated HTML now uses a CSS style sheet to make layout
  6580   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  6581   It can be changed to alter the colors/layout of generated pages.
  6582 
  6583 
  6584 *** Isar ***
  6585 
  6586 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  6587   cut_tac, subgoal_tac and thin_tac:
  6588   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  6589     locales are no longer forced to write Isar proof scripts.
  6590     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  6591     emulations.
  6592   - INCOMPATIBILITY: names of variables to be instantiated may no
  6593     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  6594     This is consistent with the instantiation attribute "where".
  6595 
  6596 * Attributes "where" and "of":
  6597   - Now take type variables of instantiated theorem into account when reading
  6598     the instantiation string.  This fixes a bug that caused instantiated
  6599     theorems to have too special types in some circumstances.
  6600   - "where" permits explicit instantiations of type variables.
  6601 
  6602 * Calculation commands "moreover" and "also" no longer interfere with
  6603   current facts ("this"), admitting arbitrary combinations with "then"
  6604   and derived forms.
  6605 
  6606 * Locales:
  6607   - Goal statements involving the context element "includes" no longer
  6608     generate theorems with internal delta predicates (those ending on
  6609     "_axioms") in the premise.
  6610     Resolve particular premise with <locale>.intro to obtain old form.
  6611   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  6612     specification and "includes" elements in goal statement.
  6613   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  6614     [intro?] and [elim?] (respectively) by default.
  6615   - Experimental command for instantiation of locales in proof contexts:
  6616         instantiate <label>[<attrs>]: <loc>
  6617     Instantiates locale <loc> and adds all its theorems to the current context
  6618     taking into account their attributes.  Label and attrs are optional
  6619     modifiers, like in theorem declarations.  If present, names of
  6620     instantiated theorems are qualified with <label>, and the attributes
  6621     <attrs> are applied after any attributes these theorems might have already.
  6622       If the locale has assumptions, a chained fact of the form
  6623     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  6624     are derived.  The command does not support old-style locales declared
  6625     with "locale (open)".
  6626       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  6627 
  6628 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  6629   (Isar) contexts.
  6630 
  6631 
  6632 *** HOL ***
  6633 
  6634 * Proof import: new image HOL4 contains the imported library from
  6635   the HOL4 system with about 2500 theorems. It is imported by
  6636   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  6637   can be used like any other Isabelle image.  See
  6638   HOL/Import/HOL/README for more information.
  6639 
  6640 * Simplifier:
  6641   - Much improved handling of linear and partial orders.
  6642     Reasoners for linear and partial orders are set up for type classes
  6643     "linorder" and "order" respectively, and are added to the default simpset
  6644     as solvers.  This means that the simplifier can build transitivity chains
  6645     to solve goals from the assumptions.
  6646   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  6647     of blast or auto after simplification become unnecessary because the goal
  6648     is solved by simplification already.
  6649 
  6650 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  6651     all proved in axiomatic type classes for semirings, rings and fields.
  6652 
  6653 * Numerics:
  6654   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  6655     now formalized using the Ring_and_Field theory mentioned above.
  6656   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  6657     than before, because now they are set up once in a generic manner.
  6658   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  6659     Look for the general versions in Ring_and_Field (and Power if they concern
  6660     exponentiation).
  6661 
  6662 * Type "rat" of the rational numbers is now available in HOL-Complex.
  6663 
  6664 * Records:
  6665   - Record types are now by default printed with their type abbreviation
  6666     instead of the list of all field types. This can be configured via
  6667     the reference "print_record_type_abbr".
  6668   - Simproc "record_upd_simproc" for simplification of multiple updates added
  6669     (not enabled by default).
  6670   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  6671     EX x. x = sel r to True (not enabled by default).
  6672   - Tactic "record_split_simp_tac" to split and simplify records added.
  6673 
  6674 * 'specification' command added, allowing for definition by
  6675   specification.  There is also an 'ax_specification' command that
  6676   introduces the new constants axiomatically.
  6677 
  6678 * arith(_tac) is now able to generate counterexamples for reals as well.
  6679 
  6680 * HOL-Algebra: new locale "ring" for non-commutative rings.
  6681 
  6682 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  6683   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  6684 
  6685 * HOL-Matrix: a first theory for matrices in HOL with an application of
  6686   matrix theory to linear programming.
  6687 
  6688 * Unions and Intersections:
  6689   The latex output syntax of UN and INT has been changed
  6690   from "\Union x \in A. B" to "\Union_{x \in A} B"
  6691   i.e. the index formulae has become a subscript.
  6692   Similarly for "\Union x. B", and for \Inter instead of \Union.
  6693 
  6694 * Unions and Intersections over Intervals:
  6695   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  6696   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  6697   like in normal math, and corresponding versions for < and for intersection.
  6698 
  6699 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  6700   lexicographic dictonary ordering has been added as "lexord".
  6701 
  6702 * ML: the legacy theory structures Int and List have been removed. They had
  6703   conflicted with ML Basis Library structures having the same names.
  6704 
  6705 * 'refute' command added to search for (finite) countermodels.  Only works
  6706   for a fragment of HOL.  The installation of an external SAT solver is
  6707   highly recommended.  See "HOL/Refute.thy" for details.
  6708 
  6709 * 'quickcheck' command: Allows to find counterexamples by evaluating
  6710   formulae under an assignment of free variables to random values.
  6711   In contrast to 'refute', it can deal with inductive datatypes,
  6712   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  6713   for examples.
  6714 
  6715 
  6716 *** HOLCF ***
  6717 
  6718 * Streams now come with concatenation and are part of the HOLCF image
  6719 
  6720 
  6721 
  6722 New in Isabelle2003 (May 2003)
  6723 ------------------------------
  6724 
  6725 *** General ***
  6726 
  6727 * Provers/simplifier:
  6728 
  6729   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  6730     Assumptions are now subject to complete mutual simplification,
  6731     not just from left to right. The simplifier now preserves
  6732     the order of assumptions.
  6733 
  6734     Potential INCOMPATIBILITY:
  6735 
  6736     -- simp sometimes diverges where the old version did
  6737        not, e.g. invoking simp on the goal
  6738 
  6739         [| P (f x); y = x; f x = f y |] ==> Q
  6740 
  6741        now gives rise to the infinite reduction sequence
  6742 
  6743         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  6744 
  6745        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  6746        kind of problem.
  6747 
  6748     -- Tactics combining classical reasoner and simplification (such as auto)
  6749        are also affected by this change, because many of them rely on
  6750        simp. They may sometimes diverge as well or yield a different numbers
  6751        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  6752        in case of problems. Sometimes subsequent calls to the classical
  6753        reasoner will fail because a preceeding call to the simplifier too
  6754        eagerly simplified the goal, e.g. deleted redundant premises.
  6755 
  6756   - The simplifier trace now shows the names of the applied rewrite rules
  6757 
  6758   - You can limit the number of recursive invocations of the simplifier
  6759     during conditional rewriting (where the simplifie tries to solve the
  6760     conditions before applying the rewrite rule):
  6761     ML "simp_depth_limit := n"
  6762     where n is an integer. Thus you can force termination where previously
  6763     the simplifier would diverge.
  6764 
  6765   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  6766 
  6767   - No longer aborts on failed congruence proof.  Instead, the
  6768     congruence is ignored.
  6769 
  6770 * Pure: New generic framework for extracting programs from constructive
  6771   proofs. See HOL/Extraction.thy for an example instantiation, as well
  6772   as HOL/Extraction for some case studies.
  6773 
  6774 * Pure: The main goal of the proof state is no longer shown by default, only
  6775 the subgoals. This behaviour is controlled by a new flag.
  6776    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  6777 (ML: Proof.show_main_goal).
  6778 
  6779 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  6780 rules whose conclusion matches subgoal 1:
  6781       PG menu: Isabelle/Isar -> Show me -> matching rules
  6782 The rules are ordered by how closely they match the subgoal.
  6783 In particular, rules that solve a subgoal outright are displayed first
  6784 (or rather last, the way they are printed).
  6785 (ML: ProofGeneral.print_intros())
  6786 
  6787 * Pure: New flag trace_unify_fail causes unification to print
  6788 diagnostic information (PG: in trace buffer) when it fails. This is
  6789 useful for figuring out why single step proofs like rule, erule or
  6790 assumption failed.
  6791 
  6792 * Pure: Locale specifications now produce predicate definitions
  6793 according to the body of text (covering assumptions modulo local
  6794 definitions); predicate "loc_axioms" covers newly introduced text,
  6795 while "loc" is cumulative wrt. all included locale expressions; the
  6796 latter view is presented only on export into the global theory
  6797 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  6798 on the old view without predicates;
  6799 
  6800 * Pure: predefined locales "var" and "struct" are useful for sharing
  6801 parameters (as in CASL, for example); just specify something like
  6802 ``var x + var y + struct M'' as import;
  6803 
  6804 * Pure: improved thms_containing: proper indexing of facts instead of
  6805 raw theorems; check validity of results wrt. current name space;
  6806 include local facts of proof configuration (also covers active
  6807 locales), cover fixed variables in index; may use "_" in term
  6808 specification; an optional limit for the number of printed facts may
  6809 be given (the default is 40);
  6810 
  6811 * Pure: disallow duplicate fact bindings within new-style theory files
  6812 (batch-mode only);
  6813 
  6814 * Provers: improved induct method: assumptions introduced by case
  6815 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6816 the goal statement); "foo" still refers to all facts collectively;
  6817 
  6818 * Provers: the function blast.overloaded has been removed: all constants
  6819 are regarded as potentially overloaded, which improves robustness in exchange
  6820 for slight decrease in efficiency;
  6821 
  6822 * Provers/linorder: New generic prover for transitivity reasoning over
  6823 linear orders.  Note: this prover is not efficient!
  6824 
  6825 * Isar: preview of problems to finish 'show' now produce an error
  6826 rather than just a warning (in interactive mode);
  6827 
  6828 
  6829 *** HOL ***
  6830 
  6831 * arith(_tac)
  6832 
  6833  - Produces a counter example if it cannot prove a goal.
  6834    Note that the counter example may be spurious if the goal is not a formula
  6835    of quantifier-free linear arithmetic.
  6836    In ProofGeneral the counter example appears in the trace buffer.
  6837 
  6838  - Knows about div k and mod k where k is a numeral of type nat or int.
  6839 
  6840  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6841    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6842    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6843 
  6844 * simp's arithmetic capabilities have been enhanced a bit: it now
  6845 takes ~= in premises into account (by performing a case split);
  6846 
  6847 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6848 are distributed over a sum of terms;
  6849 
  6850 * New tactic "trans_tac" and method "trans" instantiate
  6851 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6852 "<=", "<" and "=").
  6853 
  6854 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6855 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6856 
  6857 * 'typedef' command has new option "open" to suppress the set
  6858 definition;
  6859 
  6860 * functions Min and Max on finite sets have been introduced (theory
  6861 Finite_Set);
  6862 
  6863 * attribute [symmetric] now works for relations as well; it turns
  6864 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6865 
  6866 * induct over a !!-quantified statement (say !!x1..xn):
  6867   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6868 
  6869 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6870 %x. None. Warning: empty_def now refers to the previously hidden definition
  6871 of the empty set.
  6872 
  6873 * Algebra: formalization of classical algebra.  Intended as base for
  6874 any algebraic development in Isabelle.  Currently covers group theory
  6875 (up to Sylow's theorem) and ring theory (Universal Property of
  6876 Univariate Polynomials).  Contributions welcome;
  6877 
  6878 * GroupTheory: deleted, since its material has been moved to Algebra;
  6879 
  6880 * Complex: new directory of the complex numbers with numeric constants,
  6881 nonstandard complex numbers, and some complex analysis, standard and
  6882 nonstandard (Jacques Fleuriot);
  6883 
  6884 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6885 
  6886 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6887 Fleuriot);
  6888 
  6889 * Real/HahnBanach: updated and adapted to locales;
  6890 
  6891 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6892 Gray and Kramer);
  6893 
  6894 * UNITY: added the Meier-Sanders theory of progress sets;
  6895 
  6896 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6897 as abstract algorithms, instantiated to the JVM;
  6898 
  6899 * Bali: Java source language formalization. Type system, operational
  6900 semantics, axiomatic semantics. Supported language features:
  6901 classes, interfaces, objects,virtual methods, static methods,
  6902 static/instance fields, arrays, access modifiers, definite
  6903 assignment, exceptions.
  6904 
  6905 
  6906 *** ZF ***
  6907 
  6908 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6909 universe, etc.);
  6910 
  6911 * Main ZF: virtually all theories converted to new-style format;
  6912 
  6913 
  6914 *** ML ***
  6915 
  6916 * Pure: Tactic.prove provides sane interface for internal proofs;
  6917 omits the infamous "standard" operation, so this is more appropriate
  6918 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6919 
  6920 * Pure: improved error reporting of simprocs;
  6921 
  6922 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6923 up simprocs;
  6924 
  6925 
  6926 *** Document preparation ***
  6927 
  6928 * uses \par instead of \\ for line breaks in theory text. This may
  6929 shift some page breaks in large documents. To get the old behaviour
  6930 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6931 
  6932 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6933 other packages
  6934 
  6935 * \<euro> now needs package babel/greek instead of marvosym (which
  6936 broke \Rightarrow)
  6937 
  6938 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6939 textcomp package)
  6940 
  6941 
  6942 
  6943 New in Isabelle2002 (March 2002)
  6944 --------------------------------
  6945 
  6946 *** Document preparation ***
  6947 
  6948 * greatly simplified document preparation setup, including more
  6949 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6950 instructive isatool mkdir; users should basically be able to get
  6951 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6952 users may run a separate document processing stage manually like this:
  6953 "isatool usedir -D output HOL Test && isatool document Test/output";
  6954 
  6955 * theory dependency graph may now be incorporated into documents;
  6956 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6957 with \includegraphics of LaTeX;
  6958 
  6959 * proper spacing of consecutive markup elements, especially text
  6960 blocks after section headings;
  6961 
  6962 * support bold style (for single symbols only), input syntax is like
  6963 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6964 
  6965 * \<bullet> is now output as bold \cdot by default, which looks much
  6966 better in printed text;
  6967 
  6968 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6969 note that these symbols are currently unavailable in Proof General /
  6970 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6971 
  6972 * isatool latex no longer depends on changed TEXINPUTS, instead
  6973 isatool document copies the Isabelle style files to the target
  6974 location;
  6975 
  6976 
  6977 *** Isar ***
  6978 
  6979 * Pure/Provers: improved proof by cases and induction;
  6980   - 'case' command admits impromptu naming of parameters (such as
  6981     "case (Suc n)");
  6982   - 'induct' method divinates rule instantiation from the inductive
  6983     claim; no longer requires excessive ?P bindings for proper
  6984     instantiation of cases;
  6985   - 'induct' method properly enumerates all possibilities of set/type
  6986     rules; as a consequence facts may be also passed through *type*
  6987     rules without further ado;
  6988   - 'induct' method now derives symbolic cases from the *rulified*
  6989     rule (before it used to rulify cases stemming from the internal
  6990     atomized version); this means that the context of a non-atomic
  6991     statement becomes is included in the hypothesis, avoiding the
  6992     slightly cumbersome show "PROP ?case" form;
  6993   - 'induct' may now use elim-style induction rules without chaining
  6994     facts, using ``missing'' premises from the goal state; this allows
  6995     rules stemming from inductive sets to be applied in unstructured
  6996     scripts, while still benefitting from proper handling of non-atomic
  6997     statements; NB: major inductive premises need to be put first, all
  6998     the rest of the goal is passed through the induction;
  6999   - 'induct' proper support for mutual induction involving non-atomic
  7000     rule statements (uses the new concept of simultaneous goals, see
  7001     below);
  7002   - append all possible rule selections, but only use the first
  7003     success (no backtracking);
  7004   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  7005   - undeclared rule case names default to numbers 1, 2, 3, ...;
  7006   - added 'print_induct_rules' (covered by help item in recent Proof
  7007     General versions);
  7008   - moved induct/cases attributes to Pure, methods to Provers;
  7009   - generic method setup instantiated for FOL and HOL;
  7010 
  7011 * Pure: support multiple simultaneous goal statements, for example
  7012 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  7013 meta-level mechanism, this acts as if several individual goals had
  7014 been stated separately; in particular common proof methods need to be
  7015 repeated in order to cover all claims; note that a single elimination
  7016 step is *not* sufficient to establish the two conjunctions, so this
  7017 fails:
  7018 
  7019   assume "A & B" then have A and B ..   (*".." fails*)
  7020 
  7021 better use "obtain" in situations as above; alternative refer to
  7022 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  7023 
  7024 * Pure: proper integration with ``locales''; unlike the original
  7025 version by Florian Kammller, Isar locales package high-level proof
  7026 contexts rather than raw logical ones (e.g. we admit to include
  7027 attributes everywhere); operations on locales include merge and
  7028 rename; support for implicit arguments (``structures''); simultaneous
  7029 type-inference over imports and text; see also HOL/ex/Locales.thy for
  7030 some examples;
  7031 
  7032 * Pure: the following commands have been ``localized'', supporting a
  7033 target locale specification "(in name)": 'lemma', 'theorem',
  7034 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  7035 stored both within the locale and at the theory level (exported and
  7036 qualified by the locale name);
  7037 
  7038 * Pure: theory goals may now be specified in ``long'' form, with
  7039 ad-hoc contexts consisting of arbitrary locale elements. for example
  7040 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  7041 definitions may be given, too); the result is a meta-level rule with
  7042 the context elements being discharged in the obvious way;
  7043 
  7044 * Pure: new proof command 'using' allows to augment currently used
  7045 facts after a goal statement ('using' is syntactically analogous to
  7046 'apply', but acts on the goal's facts only); this allows chained facts
  7047 to be separated into parts given before and after a claim, as in
  7048 ``from a and b have C using d and e <proof>'';
  7049 
  7050 * Pure: renamed "antecedent" case to "rule_context";
  7051 
  7052 * Pure: new 'judgment' command records explicit information about the
  7053 object-logic embedding (used by several tools internally); no longer
  7054 use hard-wired "Trueprop";
  7055 
  7056 * Pure: added 'corollary' command;
  7057 
  7058 * Pure: fixed 'token_translation' command;
  7059 
  7060 * Pure: removed obsolete 'exported' attribute;
  7061 
  7062 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  7063 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  7064 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  7065 
  7066 * Pure: method 'atomize' presents local goal premises as object-level
  7067 statements (atomic meta-level propositions); setup controlled via
  7068 rewrite rules declarations of 'atomize' attribute; example
  7069 application: 'induct' method with proper rule statements in improper
  7070 proof *scripts*;
  7071 
  7072 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  7073 now consider the syntactic context of assumptions, giving a better
  7074 chance to get type-inference of the arguments right (this is
  7075 especially important for locales);
  7076 
  7077 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  7078 mode;
  7079 
  7080 * Pure/obtain: the formal conclusion "thesis", being marked as
  7081 ``internal'', may no longer be reference directly in the text;
  7082 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  7083 situations;
  7084 
  7085 * Pure: generic 'sym' attribute which declares a rule both as pure
  7086 'elim?' and for the 'symmetric' operation;
  7087 
  7088 * Pure: marginal comments ``--'' may now occur just anywhere in the
  7089 text; the fixed correlation with particular command syntax has been
  7090 discontinued;
  7091 
  7092 * Pure: new method 'rules' is particularly well-suited for proof
  7093 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  7094 but often produces more compact proof terms with less detours;
  7095 
  7096 * Pure/Provers/classical: simplified integration with pure rule
  7097 attributes and methods; the classical "intro?/elim?/dest?"
  7098 declarations coincide with the pure ones; the "rule" method no longer
  7099 includes classically swapped intros; "intro" and "elim" methods no
  7100 longer pick rules from the context; also got rid of ML declarations
  7101 AddXIs/AddXEs/AddXDs; all of this has some potential for
  7102 INCOMPATIBILITY;
  7103 
  7104 * Provers/classical: attribute 'swapped' produces classical inversions
  7105 of introduction rules;
  7106 
  7107 * Provers/simplifier: 'simplified' attribute may refer to explicit
  7108 rules instead of full simplifier context; 'iff' attribute handles
  7109 conditional rules;
  7110 
  7111 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  7112 
  7113 * HOL: 'recdef' now fails on unfinished automated proofs, use
  7114 "(permissive)" option to recover old behavior;
  7115 
  7116 * HOL: 'inductive' no longer features separate (collective) attributes
  7117 for 'intros' (was found too confusing);
  7118 
  7119 * HOL: properly declared induction rules less_induct and
  7120 wf_induct_rule;
  7121 
  7122 
  7123 *** HOL ***
  7124 
  7125 * HOL: moved over to sane numeral syntax; the new policy is as
  7126 follows:
  7127 
  7128   - 0 and 1 are polymorphic constants, which are defined on any
  7129   numeric type (nat, int, real etc.);
  7130 
  7131   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  7132   binary representation internally;
  7133 
  7134   - type nat has special constructor Suc, and generally prefers Suc 0
  7135   over 1::nat and Suc (Suc 0) over 2::nat;
  7136 
  7137 This change may cause significant problems of INCOMPATIBILITY; here
  7138 are some hints on converting existing sources:
  7139 
  7140   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  7141   entities, so expressions involving "-" (unary or binary minus) need
  7142   to be spaced properly;
  7143 
  7144   - existing occurrences of "1" may need to be constraint "1::nat" or
  7145   even replaced by Suc 0; similar for old "2";
  7146 
  7147   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  7148 
  7149   - remove all special provisions on numerals in proofs;
  7150 
  7151 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  7152 representation (depends on bin_arith_simps in the default context);
  7153 
  7154 * HOL: symbolic syntax for x^2 (numeral 2);
  7155 
  7156 * HOL: the class of all HOL types is now called "type" rather than
  7157 "term"; INCOMPATIBILITY, need to adapt references to this type class
  7158 in axclass/classes, instance/arities, and (usually rare) occurrences
  7159 in typings (of consts etc.); internally the class is called
  7160 "HOL.type", ML programs should refer to HOLogic.typeS;
  7161 
  7162 * HOL/record package improvements:
  7163   - new derived operations "fields" to build a partial record section,
  7164     "extend" to promote a fixed record to a record scheme, and
  7165     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  7166     declared as simp by default;
  7167   - shared operations ("more", "fields", etc.) now need to be always
  7168     qualified) --- potential INCOMPATIBILITY;
  7169   - removed "make_scheme" operations (use "make" with "extend") --
  7170     INCOMPATIBILITY;
  7171   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  7172   - provides cases/induct rules for use with corresponding Isar
  7173     methods (for concrete records, record schemes, concrete more
  7174     parts, and schematic more parts -- in that order);
  7175   - internal definitions directly based on a light-weight abstract
  7176     theory of product types over typedef rather than datatype;
  7177 
  7178 * HOL: generic code generator for generating executable ML code from
  7179 specifications; specific support for HOL constructs such as inductive
  7180 datatypes and sets, as well as recursive functions; can be invoked
  7181 via 'generate_code' theory section;
  7182 
  7183 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  7184 
  7185 * HOL: consolidated and renamed several theories.  In particular:
  7186         Ord.thy has been absorbed into HOL.thy
  7187         String.thy has been absorbed into List.thy
  7188 
  7189 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  7190 (beware of argument permutation!);
  7191 
  7192 * HOL: linorder_less_split superseded by linorder_cases;
  7193 
  7194 * HOL/List: "nodups" renamed to "distinct";
  7195 
  7196 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  7197 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  7198   - Ex_def has changed, now need to use some_eq_ex
  7199 
  7200 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  7201 in this (rare) case use:
  7202 
  7203   delSWrapper "split_all_tac"
  7204   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  7205 
  7206 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  7207 MAY FAIL;
  7208 
  7209 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  7210 Isabelle's type classes, ^ on functions and relations has too general
  7211 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  7212 necessary to attach explicit type constraints;
  7213 
  7214 * HOL/Relation: the prefix name of the infix "O" has been changed from
  7215 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  7216 renamed accordingly (eg "compI" -> "rel_compI").
  7217 
  7218 * HOL: syntax translations now work properly with numerals and records
  7219 expressions;
  7220 
  7221 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  7222 of "lam" -- INCOMPATIBILITY;
  7223 
  7224 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  7225 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  7226 renamed "Product_Type.unit";
  7227 
  7228 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  7229 
  7230 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  7231 the "cases" method);
  7232 
  7233 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  7234 Florian Kammller);
  7235 
  7236 * HOL/IMP: updated and converted to new-style theory format; several
  7237 parts turned into readable document, with proper Isar proof texts and
  7238 some explanations (by Gerwin Klein);
  7239 
  7240 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  7241 
  7242 * HOL-Hyperreal is now a logic image;
  7243 
  7244 
  7245 *** HOLCF ***
  7246 
  7247 * Isar: consts/constdefs supports mixfix syntax for continuous
  7248 operations;
  7249 
  7250 * Isar: domain package adapted to new-style theory format, e.g. see
  7251 HOLCF/ex/Dnat.thy;
  7252 
  7253 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  7254 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  7255 lift.induct_tac, always use UU instead of Undef;
  7256 
  7257 * HOLCF/IMP: updated and converted to new-style theory;
  7258 
  7259 
  7260 *** ZF ***
  7261 
  7262 * Isar: proper integration of logic-specific tools and packages,
  7263 including theory commands '(co)inductive', '(co)datatype',
  7264 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  7265 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7266 
  7267 * theory Main no longer includes AC; for the Axiom of Choice, base
  7268 your theory on Main_ZFC;
  7269 
  7270 * the integer library now covers quotients and remainders, with many
  7271 laws relating division to addition, multiplication, etc.;
  7272 
  7273 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7274 typeless version of the formalism;
  7275 
  7276 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7277 format;
  7278 
  7279 * ZF/Induct: new directory for examples of inductive definitions,
  7280 including theory Multiset for multiset orderings; converted to
  7281 new-style theory format;
  7282 
  7283 * ZF: many new theorems about lists, ordinals, etc.;
  7284 
  7285 
  7286 *** General ***
  7287 
  7288 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7289 variable proof controls level of detail: 0 = no proofs (only oracle
  7290 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7291 also ref manual for further ML interfaces;
  7292 
  7293 * Pure/axclass: removed obsolete ML interface
  7294 goal_subclass/goal_arity;
  7295 
  7296 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7297 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7298 separate tokens, so expressions involving minus need to be spaced
  7299 properly;
  7300 
  7301 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7302 rather than "infixl" or "infixr";
  7303 
  7304 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7305 sort constraint specifications in type inference; e.g. "x::_::foo"
  7306 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7307 type variable);
  7308 
  7309 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7310 control output of nested => (types); the default behavior is
  7311 "type_brackets";
  7312 
  7313 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7314 tokens into AST constants;
  7315 
  7316 * Pure/syntax: prefer later declarations of translations and print
  7317 translation functions; potential INCOMPATIBILITY: need to reverse
  7318 multiple declarations for same syntax element constant;
  7319 
  7320 * Pure/show_hyps reset by default (in accordance to existing Isar
  7321 practice);
  7322 
  7323 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7324 addSafter;
  7325 
  7326 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7327 as well;
  7328 
  7329 * system: tested support for MacOS X; should be able to get Isabelle +
  7330 Proof General to work in a plain Terminal after installing Poly/ML
  7331 (e.g. from the Isabelle distribution area) and GNU bash alone
  7332 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7333 support requires further installations, e.g. from
  7334 http://fink.sourceforge.net/);
  7335 
  7336 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7337 
  7338 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7339 of 40 MB), cf. ML_OPTIONS;
  7340 
  7341 * system: Proof General keywords specification is now part of the
  7342 Isabelle distribution (see etc/isar-keywords.el);
  7343 
  7344 * system: support for persistent Proof General sessions (refrain from
  7345 outdating all loaded theories on startup); user may create writable
  7346 logic images like this: ``isabelle -q HOL Test'';
  7347 
  7348 * system: smart selection of Isabelle process versus Isabelle
  7349 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7350 run both "isabelle" and "Isabelle" even if file names are badly
  7351 damaged (executable inspects the case of the first letter of its own
  7352 name); added separate "isabelle-process" and "isabelle-interface";
  7353 
  7354 * system: refrain from any attempt at filtering input streams; no
  7355 longer support ``8bit'' encoding of old isabelle font, instead proper
  7356 iso-latin characters may now be used; the related isatools
  7357 "symbolinput" and "nonascii" have disappeared as well;
  7358 
  7359 * system: removed old "xterm" interface (the print modes "xterm" and
  7360 "xterm_color" are still available for direct use in a suitable
  7361 terminal);
  7362 
  7363 
  7364 
  7365 New in Isabelle99-2 (February 2001)
  7366 -----------------------------------
  7367 
  7368 *** Overview of INCOMPATIBILITIES ***
  7369 
  7370 * HOL: please note that theories in the Library and elsewhere often use the
  7371 new-style (Isar) format; to refer to their theorems in an ML script you must
  7372 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7373 
  7374 * HOL: inductive package no longer splits induction rule aggressively,
  7375 but only as far as specified by the introductions given; the old
  7376 format may be recovered via ML function complete_split_rule or attribute
  7377 'split_rule (complete)';
  7378 
  7379 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7380 gfp_Tarski to gfp_unfold;
  7381 
  7382 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7383 
  7384 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7385 relation); infix "^^" has been renamed "``"; infix "``" has been
  7386 renamed "`"; "univalent" has been renamed "single_valued";
  7387 
  7388 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7389 operation;
  7390 
  7391 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7392 
  7393 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7394 
  7395 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7396 consequence, it is no longer monotonic wrt. the local goal context
  7397 (which is now passed through the inductive cases);
  7398 
  7399 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7400 \<gg> to \<ggreater>;
  7401 
  7402 
  7403 *** Document preparation ***
  7404 
  7405 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7406 available: are "it" for near math-mode best-style output, "sl" for
  7407 slanted text style, and "tt" for plain type-writer; if no
  7408 \isabellestyle command is given, output is according to slanted
  7409 type-writer);
  7410 
  7411 * support sub/super scripts (for single symbols only), input syntax is
  7412 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7413 
  7414 * some more standard symbols; see Appendix A of the system manual for
  7415 the complete list of symbols defined in isabellesym.sty;
  7416 
  7417 * improved isabelle style files; more abstract symbol implementation
  7418 (should now use \isamath{...} and \isatext{...} in custom symbol
  7419 definitions);
  7420 
  7421 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  7422 state; Note that presentation of goal states does not conform to
  7423 actual human-readable proof documents.  Please do not include goal
  7424 states into document output unless you really know what you are doing!
  7425 
  7426 * proper indentation of antiquoted output with proportional LaTeX
  7427 fonts;
  7428 
  7429 * no_document ML operator temporarily disables LaTeX document
  7430 generation;
  7431 
  7432 * isatool unsymbolize tunes sources for plain ASCII communication;
  7433 
  7434 
  7435 *** Isar ***
  7436 
  7437 * Pure: Isar now suffers initial goal statements to contain unbound
  7438 schematic variables (this does not conform to actual readable proof
  7439 documents, due to unpredictable outcome and non-compositional proof
  7440 checking); users who know what they are doing may use schematic goals
  7441 for Prolog-style synthesis of proven results;
  7442 
  7443 * Pure: assumption method (an implicit finishing) now handles actual
  7444 rules as well;
  7445 
  7446 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  7447 initial goal, declare "that" only as Pure intro (only for single
  7448 steps); the "that" rule assumption may now be involved in implicit
  7449 finishing, thus ".." becomes a feasible for trivial obtains;
  7450 
  7451 * Pure: default proof step now includes 'intro_classes'; thus trivial
  7452 instance proofs may be performed by "..";
  7453 
  7454 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  7455 statements as well;
  7456 
  7457 * Pure: more robust selection of calculational rules;
  7458 
  7459 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  7460 rule (as well as the assumption rule);
  7461 
  7462 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  7463 lemmas, using the graph browser tool;
  7464 
  7465 * Pure: predict failure of "show" in interactive mode;
  7466 
  7467 * Pure: 'thms_containing' now takes actual terms as arguments;
  7468 
  7469 * HOL: improved method 'induct' --- now handles non-atomic goals
  7470 (potential INCOMPATIBILITY); tuned error handling;
  7471 
  7472 * HOL: cases and induct rules now provide explicit hints about the
  7473 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  7474 any remaining facts are inserted into the goal verbatim;
  7475 
  7476 * HOL: local contexts (aka cases) may now contain term bindings as
  7477 well; the 'cases' and 'induct' methods new provide a ?case binding for
  7478 the result to be shown in each case;
  7479 
  7480 * HOL: added 'recdef_tc' command;
  7481 
  7482 * isatool convert assists in eliminating legacy ML scripts;
  7483 
  7484 
  7485 *** HOL ***
  7486 
  7487 * HOL/Library: a collection of generic theories to be used together
  7488 with main HOL; the theory loader path already includes this directory
  7489 by default; the following existing theories have been moved here:
  7490 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  7491 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  7492 
  7493 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  7494 modelling and verification task performed in Isabelle/HOL +
  7495 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  7496 
  7497 * HOL/Algebra: special summation operator SUM no longer exists, it has
  7498 been replaced by setsum; infix 'assoc' now has priority 50 (like
  7499 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  7500 'domain', this makes the theory consistent with mathematical
  7501 literature;
  7502 
  7503 * HOL basics: added overloaded operations "inverse" and "divide"
  7504 (infix "/"), syntax for generic "abs" operation, generic summation
  7505 operator \<Sum>;
  7506 
  7507 * HOL/typedef: simplified package, provide more useful rules (see also
  7508 HOL/subset.thy);
  7509 
  7510 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  7511 now expressed as a proper nested rule (old-style tactic scripts may
  7512 require atomize_strip_tac to cope with non-atomic premises);
  7513 
  7514 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  7515 to "split_conv" (old name still available for compatibility);
  7516 
  7517 * HOL: improved concrete syntax for strings (e.g. allows translation
  7518 rules with string literals);
  7519 
  7520 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  7521  and Fleuriot's mechanization of analysis, including the transcendental
  7522  functions for the reals;
  7523 
  7524 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  7525 
  7526 
  7527 *** CTT ***
  7528 
  7529 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  7530 "lam" is displayed as TWO lambda-symbols
  7531 
  7532 * CTT: theory Main now available, containing everything (that is, Bool
  7533 and Arith);
  7534 
  7535 
  7536 *** General ***
  7537 
  7538 * Pure: the Simplifier has been implemented properly as a derived rule
  7539 outside of the actual kernel (at last!); the overall performance
  7540 penalty in practical applications is about 50%, while reliability of
  7541 the Isabelle inference kernel has been greatly improved;
  7542 
  7543 * print modes "brackets" and "no_brackets" control output of nested =>
  7544 (types) and ==> (props); the default behaviour is "brackets";
  7545 
  7546 * Provers: fast_tac (and friends) now handle actual object-logic rules
  7547 as assumptions as well;
  7548 
  7549 * system: support Poly/ML 4.0;
  7550 
  7551 * system: isatool install handles KDE version 1 or 2;
  7552 
  7553 
  7554 
  7555 New in Isabelle99-1 (October 2000)
  7556 ----------------------------------
  7557 
  7558 *** Overview of INCOMPATIBILITIES ***
  7559 
  7560 * HOL: simplification of natural numbers is much changed; to partly
  7561 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  7562 issue the following ML commands:
  7563 
  7564   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  7565   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  7566 
  7567 * HOL: simplification no longer dives into case-expressions; this is
  7568 controlled by "t.weak_case_cong" for each datatype t;
  7569 
  7570 * HOL: nat_less_induct renamed to less_induct;
  7571 
  7572 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  7573 fixsome to patch .thy and .ML sources automatically;
  7574 
  7575   select_equality  -> some_equality
  7576   select_eq_Ex     -> some_eq_ex
  7577   selectI2EX       -> someI2_ex
  7578   selectI2         -> someI2
  7579   selectI          -> someI
  7580   select1_equality -> some1_equality
  7581   Eps_sym_eq       -> some_sym_eq_trivial
  7582   Eps_eq           -> some_eq_trivial
  7583 
  7584 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  7585 
  7586 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  7587 instead);
  7588 
  7589 * HOL: the recursion equations generated by 'recdef' are now called
  7590 f.simps instead of f.rules;
  7591 
  7592 * HOL: qed_spec_mp now also handles bounded ALL as well;
  7593 
  7594 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  7595 sometimes be needed;
  7596 
  7597 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  7598 
  7599 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  7600 
  7601 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  7602 product is now "<*>" instead of "Times"; the lexicographic product is
  7603 now "<*lex*>" instead of "**";
  7604 
  7605 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  7606 of main HOL, but was unused); better use HOL's datatype package;
  7607 
  7608 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  7609 the old syntax may be recovered as follows:
  7610 
  7611   syntax (symbols)
  7612     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  7613       (infixl "\\<oplus>" 100)
  7614 
  7615 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7616 
  7617 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  7618 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  7619 internally;
  7620 
  7621 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  7622 changed from A/r to A//r;
  7623 
  7624 * ZF: new treatment of arithmetic (nat & int) may break some old
  7625 proofs;
  7626 
  7627 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  7628 rulify -> rule_format, elimify -> elim_format, ...);
  7629 
  7630 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7631 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  7632 should have to change intro!! to intro? only); replaced "delrule" by
  7633 "rule del";
  7634 
  7635 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  7636 
  7637 * Provers: strengthened force_tac by using new first_best_tac;
  7638 
  7639 * LaTeX document preparation: several changes of isabelle.sty (see
  7640 lib/texinputs);
  7641 
  7642 
  7643 *** Document preparation ***
  7644 
  7645 * formal comments (text blocks etc.) in new-style theories may now
  7646 contain antiquotations of thm/prop/term/typ/text to be presented
  7647 according to latex print mode; concrete syntax is like this:
  7648 @{term[show_types] "f(x) = a + x"};
  7649 
  7650 * isatool mkdir provides easy setup of Isabelle session directories,
  7651 including proper document sources;
  7652 
  7653 * generated LaTeX sources are now deleted after successful run
  7654 (isatool document -c); may retain a copy somewhere else via -D option
  7655 of isatool usedir;
  7656 
  7657 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  7658 style files, achieving self-contained LaTeX sources and simplifying
  7659 LaTeX debugging;
  7660 
  7661 * old-style theories now produce (crude) LaTeX output as well;
  7662 
  7663 * browser info session directories are now self-contained (may be put
  7664 on WWW server seperately); improved graphs of nested sessions; removed
  7665 graph for 'all sessions';
  7666 
  7667 * several improvements in isabelle style files; \isabellestyle{it}
  7668 produces fake math mode output; \isamarkupheader is now \section by
  7669 default; see lib/texinputs/isabelle.sty etc.;
  7670 
  7671 
  7672 *** Isar ***
  7673 
  7674 * Isar/Pure: local results and corresponding term bindings are now
  7675 subject to Hindley-Milner polymorphism (similar to ML); this
  7676 accommodates incremental type-inference very nicely;
  7677 
  7678 * Isar/Pure: new derived language element 'obtain' supports
  7679 generalized existence reasoning;
  7680 
  7681 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  7682 support accumulation of results, without applying any rules yet;
  7683 useful to collect intermediate results without explicit name
  7684 references, and for use with transitivity rules with more than 2
  7685 premises;
  7686 
  7687 * Isar/Pure: scalable support for case-analysis type proofs: new
  7688 'case' language element refers to local contexts symbolically, as
  7689 produced by certain proof methods; internally, case names are attached
  7690 to theorems as "tags";
  7691 
  7692 * Isar/Pure: theory command 'hide' removes declarations from
  7693 class/type/const name spaces;
  7694 
  7695 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  7696 indicate potential overloading;
  7697 
  7698 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  7699 
  7700 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  7701 "{a,b,c}" instead of {a,b,c};
  7702 
  7703 * Isar/Pure now provides its own version of intro/elim/dest
  7704 attributes; useful for building new logics, but beware of confusion
  7705 with the version in Provers/classical;
  7706 
  7707 * Isar/Pure: the local context of (non-atomic) goals is provided via
  7708 case name 'antecedent';
  7709 
  7710 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  7711 to the current context is now done automatically);
  7712 
  7713 * Isar/Pure: theory command 'method_setup' provides a simple interface
  7714 for definining proof methods in ML;
  7715 
  7716 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7717 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  7718 most cases, one should have to change intro!! to intro? only);
  7719 replaced "delrule" by "rule del";
  7720 
  7721 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  7722 'symmetric' attribute (the latter supercedes [RS sym]);
  7723 
  7724 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  7725 method modifier); 'simp' method: 'only:' modifier removes loopers as
  7726 well (including splits);
  7727 
  7728 * Isar/Provers: Simplifier and Classical methods now support all kind
  7729 of modifiers used in the past, including 'cong', 'iff', etc.
  7730 
  7731 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  7732 of Simplifier and Classical reasoner);
  7733 
  7734 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  7735 now support named cases; major packages (inductive, datatype, primrec,
  7736 recdef) support case names and properly name parameters;
  7737 
  7738 * Isar/HOL: new transitivity rules for substitution in inequalities --
  7739 monotonicity conditions are extracted to be proven at end of
  7740 calculations;
  7741 
  7742 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  7743 method anyway;
  7744 
  7745 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  7746 split_if split_if_asm; datatype package provides theorems foo.splits =
  7747 foo.split foo.split_asm for each datatype;
  7748 
  7749 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  7750 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  7751 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  7752 use "(cases (simplified))" method in proper proof texts);
  7753 
  7754 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  7755 
  7756 * Isar: names of theorems etc. may be natural numbers as well;
  7757 
  7758 * Isar: 'pr' command: optional arguments for goals_limit and
  7759 ProofContext.prems_limit; no longer prints theory contexts, but only
  7760 proof states;
  7761 
  7762 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  7763 additional print modes to be specified; e.g. "pr(latex)" will print
  7764 proof state according to the Isabelle LaTeX style;
  7765 
  7766 * Isar: improved support for emulating tactic scripts, including proof
  7767 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  7768 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  7769 (for HOL datatypes);
  7770 
  7771 * Isar: simplified (more robust) goal selection of proof methods: 1st
  7772 goal, all goals, or explicit goal specifier (tactic emulation); thus
  7773 'proof method scripts' have to be in depth-first order;
  7774 
  7775 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  7776 
  7777 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  7778 should instead use individual commands for printing items
  7779 (print_commands, print_methods etc.);
  7780 
  7781 * Isar: added 'nothing' --- the empty list of theorems;
  7782 
  7783 
  7784 *** HOL ***
  7785 
  7786 * HOL/MicroJava: formalization of a fragment of Java, together with a
  7787 corresponding virtual machine and a specification of its bytecode
  7788 verifier and a lightweight bytecode verifier, including proofs of
  7789 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  7790 Cornelia Pusch (see also the homepage of project Bali at
  7791 http://isabelle.in.tum.de/Bali/);
  7792 
  7793 * HOL/Algebra: new theory of rings and univariate polynomials, by
  7794 Clemens Ballarin;
  7795 
  7796 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  7797 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  7798 Rasmussen;
  7799 
  7800 * HOL/Lattice: fundamental concepts of lattice theory and order
  7801 structures, including duals, properties of bounds versus algebraic
  7802 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  7803 Theorem for complete lattices etc.; may also serve as a demonstration
  7804 for abstract algebraic reasoning using axiomatic type classes, and
  7805 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  7806 
  7807 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  7808 von Oheimb;
  7809 
  7810 * HOL/IMPP: extension of IMP with local variables and mutually
  7811 recursive procedures, by David von Oheimb;
  7812 
  7813 * HOL/Lambda: converted into new-style theory and document;
  7814 
  7815 * HOL/ex/Multiquote: example of multiple nested quotations and
  7816 anti-quotations -- basically a generalized version of de-Bruijn
  7817 representation; very useful in avoiding lifting of operations;
  7818 
  7819 * HOL/record: added general record equality rule to simpset; fixed
  7820 select-update simplification procedure to handle extended records as
  7821 well; admit "r" as field name;
  7822 
  7823 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  7824 other numeric types and also as the identity of groups, rings, etc.;
  7825 
  7826 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  7827 Types nat and int belong to this axclass;
  7828 
  7829 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  7830    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  7831    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  7832   two terms #m*u and #n*u are replaced by #(m+n)*u
  7833     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  7834   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  7835     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  7836 
  7837 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  7838 powerful prover for predicate logic but knows nothing of clasets; see
  7839 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  7840 
  7841 * HOL: new version of "case_tac" subsumes both boolean case split and
  7842 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  7843 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  7844 
  7845 * HOL: simplification no longer dives into case-expressions: only the
  7846 selector expression is simplified, but not the remaining arms; to
  7847 enable full simplification of case-expressions for datatype t, you may
  7848 remove t.weak_case_cong from the simpset, either globally (Delcongs
  7849 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  7850 
  7851 * HOL/recdef: the recursion equations generated by 'recdef' for
  7852 function 'f' are now called f.simps instead of f.rules; if all
  7853 termination conditions are proved automatically, these simplification
  7854 rules are added to the simpset, as in primrec; rules may be named
  7855 individually as well, resulting in a separate list of theorems for
  7856 each equation;
  7857 
  7858 * HOL/While is a new theory that provides a while-combinator. It
  7859 permits the definition of tail-recursive functions without the
  7860 provision of a termination measure. The latter is necessary once the
  7861 invariant proof rule for while is applied.
  7862 
  7863 * HOL: new (overloaded) notation for the set of elements below/above
  7864 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7865 
  7866 * HOL: theorems impI, allI, ballI bound as "strip";
  7867 
  7868 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7869 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7870 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7871 
  7872 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7873 
  7874 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7875 main HOL, but was unused);
  7876 
  7877 * HOL: fewer consts declared as global (e.g. have to refer to
  7878 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7879 
  7880 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7881 in case of overlap with user translations (e.g. judgements over
  7882 tuples); (note that the underlying logical represenation is still
  7883 bogus);
  7884 
  7885 
  7886 *** ZF ***
  7887 
  7888 * ZF: simplification automatically cancels common terms in arithmetic
  7889 expressions over nat and int;
  7890 
  7891 * ZF: new treatment of nat to minimize type-checking: all operators
  7892 coerce their operands to a natural number using the function natify,
  7893 making the algebraic laws unconditional;
  7894 
  7895 * ZF: as above, for int: operators coerce their operands to an integer
  7896 using the function intify;
  7897 
  7898 * ZF: the integer library now contains many of the usual laws for the
  7899 orderings, including $<=, and monotonicity laws for $+ and $*;
  7900 
  7901 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7902 simplification;
  7903 
  7904 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7905 to the simplifier and classical reasoner simultaneously;
  7906 
  7907 
  7908 *** General ***
  7909 
  7910 * Provers: blast_tac now handles actual object-logic rules as
  7911 assumptions; note that auto_tac uses blast_tac internally as well;
  7912 
  7913 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7914 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7915 
  7916 * Provers: delrules now handles destruct rules as well (no longer need
  7917 explicit make_elim);
  7918 
  7919 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7920   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7921 use instead the strong form,
  7922   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7923 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7924 from destruct-rules;
  7925 
  7926 * Provers: Simplifier.easy_setup provides a fast path to basic
  7927 Simplifier setup for new object-logics;
  7928 
  7929 * Pure: AST translation rules no longer require constant head on LHS;
  7930 
  7931 * Pure: improved name spaces: ambiguous output is qualified; support
  7932 for hiding of names;
  7933 
  7934 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7935 XSYMBOL_HOME; no longer need to do manual configuration in most
  7936 situations;
  7937 
  7938 * system: compression of ML heaps images may now be controlled via -c
  7939 option of isabelle and isatool usedir (currently only observed by
  7940 Poly/ML);
  7941 
  7942 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7943 useful for remote X11);
  7944 
  7945 * system: provide TAGS file for Isabelle sources;
  7946 
  7947 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7948 order;
  7949 
  7950 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7951 timing flag supersedes proof_timing and Toplevel.trace;
  7952 
  7953 * ML: new combinators |>> and |>>> for incremental transformations
  7954 with secondary results (e.g. certain theory extensions):
  7955 
  7956 * ML: PureThy.add_defs gets additional argument to indicate potential
  7957 overloading (usually false);
  7958 
  7959 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7960 results;
  7961 
  7962 
  7963 
  7964 New in Isabelle99 (October 1999)
  7965 --------------------------------
  7966 
  7967 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7968 
  7969 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7970 are no longer simplified.  (This allows the simplifier to unfold recursive
  7971 functional programs.)  To restore the old behaviour, declare
  7972 
  7973     Delcongs [if_weak_cong];
  7974 
  7975 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7976 complement;
  7977 
  7978 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7979 
  7980 * HOL/datatype: mutual_induct_tac no longer exists --
  7981   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7982 
  7983 * HOL/typedef: fixed type inference for representing set; type
  7984 arguments now have to occur explicitly on the rhs as type constraints;
  7985 
  7986 * ZF: The con_defs part of an inductive definition may no longer refer
  7987 to constants declared in the same theory;
  7988 
  7989 * HOL, ZF: the function mk_cases, generated by the inductive
  7990 definition package, has lost an argument.  To simplify its result, it
  7991 uses the default simpset instead of a supplied list of theorems.
  7992 
  7993 * HOL/List: the constructors of type list are now Nil and Cons;
  7994 
  7995 * Simplifier: the type of the infix ML functions
  7996         setSSolver addSSolver setSolver addSolver
  7997 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7998 for packaging solvers. A solver is created via
  7999         mk_solver: string -> (thm list -> int -> tactic) -> solver
  8000 where the string argument is only a comment.
  8001 
  8002 
  8003 *** Proof tools ***
  8004 
  8005 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  8006 decision procedure for linear arithmetic. Currently it is used for
  8007 types `nat', `int', and `real' in HOL (see below); it can, should and
  8008 will be instantiated for other types and logics as well.
  8009 
  8010 * The simplifier now accepts rewrite rules with flexible heads, eg
  8011      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  8012   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  8013   matching.
  8014 
  8015 
  8016 *** General ***
  8017 
  8018 * New Isabelle/Isar subsystem provides an alternative to traditional
  8019 tactical theorem proving; together with the ProofGeneral/isar user
  8020 interface it offers an interactive environment for developing human
  8021 readable proof documents (Isar == Intelligible semi-automated
  8022 reasoning); for further information see isatool doc isar-ref,
  8023 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  8024 
  8025 * improved and simplified presentation of theories: better HTML markup
  8026 (including colors), graph views in several sizes; isatool usedir now
  8027 provides a proper interface for user theories (via -P option); actual
  8028 document preparation based on (PDF)LaTeX is available as well (for
  8029 new-style theories only); see isatool doc system for more information;
  8030 
  8031 * native support for Proof General, both for classic Isabelle and
  8032 Isabelle/Isar;
  8033 
  8034 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  8035 using the graph browser tool;
  8036 
  8037 * Isabelle manuals now also available as PDF;
  8038 
  8039 * theory loader rewritten from scratch (may not be fully
  8040 bug-compatible); old loadpath variable has been replaced by show_path,
  8041 add_path, del_path, reset_path functions; new operations such as
  8042 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  8043 isatool doc ref);
  8044 
  8045 * improved isatool install: option -k creates KDE application icon,
  8046 option -p DIR installs standalone binaries;
  8047 
  8048 * added ML_PLATFORM setting (useful for cross-platform installations);
  8049 more robust handling of platform specific ML images for SML/NJ;
  8050 
  8051 * the settings environment is now statically scoped, i.e. it is never
  8052 created again in sub-processes invoked from isabelle, isatool, or
  8053 Isabelle;
  8054 
  8055 * path element specification '~~' refers to '$ISABELLE_HOME';
  8056 
  8057 * in locales, the "assumes" and "defines" parts may be omitted if
  8058 empty;
  8059 
  8060 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  8061 long arrows);
  8062 
  8063 * new print_mode "HTML";
  8064 
  8065 * new flag show_tags controls display of tags of theorems (which are
  8066 basically just comments that may be attached by some tools);
  8067 
  8068 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  8069 mode and goal output format:
  8070 
  8071 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  8072 244c244
  8073 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  8074 ---
  8075 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  8076 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  8077 181c181
  8078 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  8079 ---
  8080 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  8081 
  8082 * function bind_thms stores lists of theorems (cf. bind_thm);
  8083 
  8084 * new shorthand tactics ftac, eatac, datac, fatac;
  8085 
  8086 * qed (and friends) now accept "" as result name; in that case the
  8087 theorem is not stored, but proper checks and presentation of the
  8088 result still apply;
  8089 
  8090 * theorem database now also indexes constants "Trueprop", "all",
  8091 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  8092 
  8093 
  8094 *** HOL ***
  8095 
  8096 ** HOL arithmetic **
  8097 
  8098 * There are now decision procedures for linear arithmetic over nat and
  8099 int:
  8100 
  8101 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  8102 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  8103 are treated as atomic; subformulae not involving type `nat' or `int'
  8104 are ignored; quantified subformulae are ignored unless they are
  8105 positive universal or negative existential. The tactic has to be
  8106 invoked by hand and can be a little bit slow. In particular, the
  8107 running time is exponential in the number of occurrences of `min' and
  8108 `max', and `-' on `nat'.
  8109 
  8110 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  8111 (negated) (in)equalities among the premises and the conclusion into
  8112 account (i.e. no compound formulae) and does not know about `min' and
  8113 `max', and `-' on `nat'. It is fast and is used automatically by the
  8114 simplifier.
  8115 
  8116 NB: At the moment, these decision procedures do not cope with mixed
  8117 nat/int formulae where the two parts interact, such as `m < n ==>
  8118 int(m) < int(n)'.
  8119 
  8120 * HOL/Numeral provides a generic theory of numerals (encoded
  8121 efficiently as bit strings); setup for types nat/int/real is in place;
  8122 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  8123 int, existing theories and proof scripts may require a few additional
  8124 type constraints;
  8125 
  8126 * integer division and remainder can now be performed on constant
  8127 arguments;
  8128 
  8129 * many properties of integer multiplication, division and remainder
  8130 are now available;
  8131 
  8132 * An interface to the Stanford Validity Checker (SVC) is available through the
  8133 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  8134 are proved automatically.  SVC must be installed separately, and its results
  8135 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  8136 invocation of the underlying oracle).  For SVC see
  8137   http://verify.stanford.edu/SVC
  8138 
  8139 * IsaMakefile: the HOL-Real target now builds an actual image;
  8140 
  8141 
  8142 ** HOL misc **
  8143 
  8144 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  8145 (in Isabelle/Isar) -- by Gertrud Bauer;
  8146 
  8147 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  8148 analysis for assembly languages with subtypes;
  8149 
  8150 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  8151 -- avoids syntactic ambiguities and treats state, transition, and
  8152 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  8153 changed syntax and (many) tactics;
  8154 
  8155 * HOL/inductive: Now also handles more general introduction rules such
  8156   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  8157   theorems are now maintained within the theory (maintained via the
  8158   "mono" attribute);
  8159 
  8160 * HOL/datatype: Now also handles arbitrarily branching datatypes
  8161   (using function types) such as
  8162 
  8163   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  8164 
  8165 * HOL/record: record_simproc (part of the default simpset) takes care
  8166 of selectors applied to updated records; record_split_tac is no longer
  8167 part of the default claset; update_defs may now be removed from the
  8168 simpset in many cases; COMPATIBILITY: old behavior achieved by
  8169 
  8170   claset_ref () := claset() addSWrapper record_split_wrapper;
  8171   Delsimprocs [record_simproc]
  8172 
  8173 * HOL/typedef: fixed type inference for representing set; type
  8174 arguments now have to occur explicitly on the rhs as type constraints;
  8175 
  8176 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  8177 names rather than an ML expression;
  8178 
  8179 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  8180 supplied later.  Program schemes can be defined, such as
  8181     "While B C s = (if B s then While B C (C s) else s)"
  8182 where the well-founded relation can be chosen after B and C have been given.
  8183 
  8184 * HOL/List: the constructors of type list are now Nil and Cons;
  8185 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  8186 course, ML tools referring to List.list.op # etc. have to be adapted;
  8187 
  8188 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  8189 disabled by default; run isabelle with option -m HOL to get back to
  8190 the original Gordon/HOL-style output;
  8191 
  8192 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  8193 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  8194 
  8195 * HOL basic syntax simplified (more orthogonal): all variants of
  8196 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  8197 Eps operator is provided as well: "SOME x. P[x]";
  8198 
  8199 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  8200 
  8201 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  8202 thus available for user theories;
  8203 
  8204 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  8205 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  8206 time;
  8207 
  8208 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  8209 several times and then mp;
  8210 
  8211 
  8212 *** LK ***
  8213 
  8214 * the notation <<...>> is now available as a notation for sequences of
  8215 formulas;
  8216 
  8217 * the simplifier is now installed
  8218 
  8219 * the axiom system has been generalized (thanks to Soren Heilmann)
  8220 
  8221 * the classical reasoner now has a default rule database
  8222 
  8223 
  8224 *** ZF ***
  8225 
  8226 * new primrec section allows primitive recursive functions to be given
  8227 directly (as in HOL) over datatypes and the natural numbers;
  8228 
  8229 * new tactics induct_tac and exhaust_tac for induction (or case
  8230 analysis) over datatypes and the natural numbers;
  8231 
  8232 * the datatype declaration of type T now defines the recursor T_rec;
  8233 
  8234 * simplification automatically does freeness reasoning for datatype
  8235 constructors;
  8236 
  8237 * automatic type-inference, with AddTCs command to insert new
  8238 type-checking rules;
  8239 
  8240 * datatype introduction rules are now added as Safe Introduction rules
  8241 to the claset;
  8242 
  8243 * the syntax "if P then x else y" is now available in addition to
  8244 if(P,x,y);
  8245 
  8246 
  8247 *** Internal programming interfaces ***
  8248 
  8249 * tuned simplifier trace output; new flag debug_simp;
  8250 
  8251 * structures Vartab / Termtab (instances of TableFun) offer efficient
  8252 tables indexed by indexname_ord / term_ord (compatible with aconv);
  8253 
  8254 * AxClass.axclass_tac lost the theory argument;
  8255 
  8256 * tuned current_goals_markers semantics: begin / end goal avoids
  8257 printing empty lines;
  8258 
  8259 * removed prs and prs_fn hook, which was broken because it did not
  8260 include \n in its semantics, forcing writeln to add one
  8261 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  8262 string -> unit if you really want to output text without newline;
  8263 
  8264 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  8265 plain output, interface builders may have to enable 'isabelle_font'
  8266 mode to get Isabelle font glyphs as before;
  8267 
  8268 * refined token_translation interface; INCOMPATIBILITY: output length
  8269 now of type real instead of int;
  8270 
  8271 * theory loader actions may be traced via new ThyInfo.add_hook
  8272 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8273 your own database of information attached to *whole* theories -- as
  8274 opposed to intra-theory data slots offered via TheoryDataFun;
  8275 
  8276 * proper handling of dangling sort hypotheses (at last!);
  8277 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8278 extra sort hypotheses that can be witnessed from the type signature;
  8279 the force_strip_shyps flag is gone, any remaining shyps are simply
  8280 left in the theorem (with a warning issued by strip_shyps_warning);
  8281 
  8282 
  8283 
  8284 New in Isabelle98-1 (October 1998)
  8285 ----------------------------------
  8286 
  8287 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8288 
  8289 * several changes of automated proof tools;
  8290 
  8291 * HOL: major changes to the inductive and datatype packages, including
  8292 some minor incompatibilities of theory syntax;
  8293 
  8294 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8295 called `inj_on';
  8296 
  8297 * HOL: removed duplicate thms in Arith:
  8298   less_imp_add_less  should be replaced by  trans_less_add1
  8299   le_imp_add_le      should be replaced by  trans_le_add1
  8300 
  8301 * HOL: unary minus is now overloaded (new type constraints may be
  8302 required);
  8303 
  8304 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8305 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8306 now taken as an integer constant.
  8307 
  8308 * Pure: ML function 'theory_of' renamed to 'theory';
  8309 
  8310 
  8311 *** Proof tools ***
  8312 
  8313 * Simplifier:
  8314   1. Asm_full_simp_tac is now more aggressive.
  8315      1. It will sometimes reorient premises if that increases their power to
  8316         simplify.
  8317      2. It does no longer proceed strictly from left to right but may also
  8318         rotate premises to achieve further simplification.
  8319      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8320      old Asm_full_simp_tac in that it does not rotate premises.
  8321   2. The simplifier now knows a little bit about nat-arithmetic.
  8322 
  8323 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8324 allows for selected deletion of wrappers, by introduction of names for
  8325 wrapper functionals.  This implies that addbefore, addSbefore,
  8326 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8327 and that adding two tactics with the same name overwrites the first
  8328 one (emitting a warning).
  8329   type wrapper = (int -> tactic) -> (int -> tactic)
  8330   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8331   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8332   delWrapper, delSWrapper: claset *  string            -> claset
  8333   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8334 
  8335 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8336 semantics; addbefore now affects only the unsafe part of step_tac
  8337 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8338 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8339 by Force_tac;
  8340 
  8341 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8342 compWrapper; added safe wrapper (and access functions for it);
  8343 
  8344 * HOL/split_all_tac is now much faster and fails if there is nothing
  8345 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8346 and the names of the automatically generated variables have changed.
  8347 split_all_tac has moved within claset() from unsafe wrappers to safe
  8348 wrappers, which means that !!-bound variables are split much more
  8349 aggressively, and safe_tac and clarify_tac now split such variables.
  8350 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8351 Note: the same holds for record_split_tac, which does the job of
  8352 split_all_tac for record fields.
  8353 
  8354 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8355 permanently to the default simpset using Addsplits just like
  8356 Addsimps. They can be removed via Delsplits just like
  8357 Delsimps. Lower-case versions are also available.
  8358 
  8359 * HOL/Simplifier: The rule split_if is now part of the default
  8360 simpset. This means that the simplifier will eliminate all occurrences
  8361 of if-then-else in the conclusion of a goal. To prevent this, you can
  8362 either remove split_if completely from the default simpset by
  8363 `Delsplits [split_if]' or remove it in a specific call of the
  8364 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8365 other case splitting rules to/from the default simpset: every datatype
  8366 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8367 t is the name of the datatype).
  8368 
  8369 * Classical reasoner / Simplifier combination: new force_tac (and
  8370 derivatives Force_tac, force) combines rewriting and classical
  8371 reasoning (and whatever other tools) similarly to auto_tac, but is
  8372 aimed to solve the given subgoal completely.
  8373 
  8374 
  8375 *** General ***
  8376 
  8377 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8378 and `goalw': the theory is no longer needed as an explicit argument -
  8379 the current theory context is used; assumptions are no longer returned
  8380 at the ML-level unless one of them starts with ==> or !!; it is
  8381 recommended to convert to these new commands using isatool fixgoal
  8382 (backup your sources first!);
  8383 
  8384 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8385 the current theory context, and 'theory' to lookup stored theories;
  8386 
  8387 * new theory section 'locale' for declaring constants, assumptions and
  8388 definitions that have local scope;
  8389 
  8390 * new theory section 'nonterminals' for purely syntactic types;
  8391 
  8392 * new theory section 'setup' for generic ML setup functions
  8393 (e.g. package initialization);
  8394 
  8395 * the distribution now includes Isabelle icons: see
  8396 lib/logo/isabelle-{small,tiny}.xpm;
  8397 
  8398 * isatool install - install binaries with absolute references to
  8399 ISABELLE_HOME/bin;
  8400 
  8401 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8402 
  8403 * print mode 'emacs' reserved for Isamode;
  8404 
  8405 * support multiple print (ast) translations per constant name;
  8406 
  8407 * theorems involving oracles are now printed with a suffixed [!];
  8408 
  8409 
  8410 *** HOL ***
  8411 
  8412 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8413 
  8414 * HOL/inductive package reorganized and improved: now supports mutual
  8415 definitions such as
  8416 
  8417   inductive EVEN ODD
  8418     intrs
  8419       null "0 : EVEN"
  8420       oddI "n : EVEN ==> Suc n : ODD"
  8421       evenI "n : ODD ==> Suc n : EVEN"
  8422 
  8423 new theorem list "elims" contains an elimination rule for each of the
  8424 recursive sets; inductive definitions now handle disjunctive premises
  8425 correctly (also ZF);
  8426 
  8427 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  8428 "mutual_induct" no longer exists - the induction rule is always
  8429 contained in "induct";
  8430 
  8431 
  8432 * HOL/datatype package re-implemented and greatly improved: now
  8433 supports mutually recursive datatypes such as
  8434 
  8435   datatype
  8436     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  8437             | SUM ('a aexp) ('a aexp)
  8438             | DIFF ('a aexp) ('a aexp)
  8439             | NUM 'a
  8440   and
  8441     'a bexp = LESS ('a aexp) ('a aexp)
  8442             | AND ('a bexp) ('a bexp)
  8443             | OR ('a bexp) ('a bexp)
  8444 
  8445 as well as indirectly recursive datatypes such as
  8446 
  8447   datatype
  8448     ('a, 'b) term = Var 'a
  8449                   | App 'b ((('a, 'b) term) list)
  8450 
  8451 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  8452 induction on mutually / indirectly recursive datatypes.
  8453 
  8454 Primrec equations are now stored in theory and can be accessed via
  8455 <function_name>.simps.
  8456 
  8457 INCOMPATIBILITIES:
  8458 
  8459   - Theories using datatypes must now have theory Datatype as an
  8460     ancestor.
  8461   - The specific <typename>.induct_tac no longer exists - use the
  8462     generic induct_tac instead.
  8463   - natE has been renamed to nat.exhaust - use exhaust_tac
  8464     instead of res_inst_tac ... natE. Note that the variable
  8465     names in nat.exhaust differ from the names in natE, this
  8466     may cause some "fragile" proofs to fail.
  8467   - The theorems split_<typename>_case and split_<typename>_case_asm
  8468     have been renamed to <typename>.split and <typename>.split_asm.
  8469   - Since default sorts of type variables are now handled correctly,
  8470     some datatype definitions may have to be annotated with explicit
  8471     sort constraints.
  8472   - Primrec definitions no longer require function name and type
  8473     of recursive argument.
  8474 
  8475 Consider using isatool fixdatatype to adapt your theories and proof
  8476 scripts to the new package (backup your sources first!).
  8477 
  8478 
  8479 * HOL/record package: considerably improved implementation; now
  8480 includes concrete syntax for record types, terms, updates; theorems
  8481 for surjective pairing and splitting !!-bound record variables; proof
  8482 support is as follows:
  8483 
  8484   1) standard conversions (selectors or updates applied to record
  8485 constructor terms) are part of the standard simpset;
  8486 
  8487   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  8488 made part of standard simpset and claset via addIffs;
  8489 
  8490   3) a tactic for record field splitting (record_split_tac) is part of
  8491 the standard claset (addSWrapper);
  8492 
  8493 To get a better idea about these rules you may retrieve them via
  8494 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  8495 the name of your record type.
  8496 
  8497 The split tactic 3) conceptually simplifies by the following rule:
  8498 
  8499   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  8500 
  8501 Thus any record variable that is bound by meta-all will automatically
  8502 blow up into some record constructor term, consequently the
  8503 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  8504 solve record problems automatically.
  8505 
  8506 
  8507 * reorganized the main HOL image: HOL/Integ and String loaded by
  8508 default; theory Main includes everything;
  8509 
  8510 * automatic simplification of integer sums and comparisons, using cancellation;
  8511 
  8512 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  8513 
  8514 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  8515 
  8516 * many new identities for unions, intersections, set difference, etc.;
  8517 
  8518 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  8519 called split_if, split_split, split_sum_case and split_nat_case (to go
  8520 with add/delsplits);
  8521 
  8522 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  8523 (?x::unit) = (); this is made part of the default simpset, which COULD
  8524 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  8525 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  8526 unit_abs_eta_conv is added in order to counter the effect of
  8527 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  8528 %u.f();
  8529 
  8530 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  8531 makes more sense);
  8532 
  8533 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8534   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8535   disjointness reasoning but breaking a few old proofs.
  8536 
  8537 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  8538 to 'converse' from 'inverse' (for compatibility with ZF and some
  8539 literature);
  8540 
  8541 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  8542 the well-founded relation;
  8543 
  8544 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  8545     Compl A.  The "Compl" syntax remains available as input syntax for this
  8546     release ONLY.
  8547 
  8548 * HOL/Update: new theory of function updates:
  8549     f(a:=b) == %x. if x=a then b else f x
  8550 may also be iterated as in f(a:=b,c:=d,...);
  8551 
  8552 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  8553 
  8554 * HOL/List:
  8555   - new function list_update written xs[i:=v] that updates the i-th
  8556     list position. May also be iterated as in xs[i:=a,j:=b,...].
  8557   - new function `upt' written [i..j(] which generates the list
  8558     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  8559     bound write [i..j], which is a shorthand for [i..j+1(].
  8560   - new lexicographic orderings and corresponding wellfoundedness theorems.
  8561 
  8562 * HOL/Arith:
  8563   - removed 'pred' (predecessor) function;
  8564   - generalized some theorems about n-1;
  8565   - many new laws about "div" and "mod";
  8566   - new laws about greatest common divisors (see theory ex/Primes);
  8567 
  8568 * HOL/Relation: renamed the relational operator r^-1 "converse"
  8569 instead of "inverse";
  8570 
  8571 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  8572   of the multiset ordering;
  8573 
  8574 * directory HOL/Real: a construction of the reals using Dedekind cuts
  8575   (not included by default);
  8576 
  8577 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  8578 
  8579 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  8580   programs, i.e. different program variables may have different types.
  8581 
  8582 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8583   [previously, this check worked only if the rewrite rule was unconditional]
  8584   Now rew can involve either definitions or equalities (either == or =).
  8585 
  8586 
  8587 *** ZF ***
  8588 
  8589 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  8590   only the theorems proved on ZF.ML;
  8591 
  8592 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8593   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8594   disjointness reasoning but breaking a few old proofs.
  8595 
  8596 * ZF/Update: new theory of function updates
  8597     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  8598   may also be iterated as in f(a:=b,c:=d,...);
  8599 
  8600 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  8601 
  8602 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8603   [previously, this check worked only if the rewrite rule was unconditional]
  8604   Now rew can involve either definitions or equalities (either == or =).
  8605 
  8606 * case_tac provided for compatibility with HOL
  8607     (like the old excluded_middle_tac, but with subgoals swapped)
  8608 
  8609 
  8610 *** Internal programming interfaces ***
  8611 
  8612 * Pure: several new basic modules made available for general use, see
  8613 also src/Pure/README;
  8614 
  8615 * improved the theory data mechanism to support encapsulation (data
  8616 kind name replaced by private Object.kind, acting as authorization
  8617 key); new type-safe user interface via functor TheoryDataFun; generic
  8618 print_data function becomes basically useless;
  8619 
  8620 * removed global_names compatibility flag -- all theory declarations
  8621 are qualified by default;
  8622 
  8623 * module Pure/Syntax now offers quote / antiquote translation
  8624 functions (useful for Hoare logic etc. with implicit dependencies);
  8625 see HOL/ex/Antiquote for an example use;
  8626 
  8627 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  8628 cterm -> thm;
  8629 
  8630 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  8631 subgoal;
  8632 
  8633 * Display.print_goals function moved to Locale.print_goals;
  8634 
  8635 * standard print function for goals supports current_goals_markers
  8636 variable for marking begin of proof, end of proof, start of goal; the
  8637 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  8638 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  8639 for example;
  8640 
  8641 
  8642 
  8643 New in Isabelle98 (January 1998)
  8644 --------------------------------
  8645 
  8646 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8647 
  8648 * changed lexical syntax of terms / types: dots made part of long
  8649 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  8650 
  8651 * simpset (and claset) reference variable replaced by functions
  8652 simpset / simpset_ref;
  8653 
  8654 * no longer supports theory aliases (via merge) and non-trivial
  8655 implicit merge of thms' signatures;
  8656 
  8657 * most internal names of constants changed due to qualified names;
  8658 
  8659 * changed Pure/Sequence interface (see Pure/seq.ML);
  8660 
  8661 
  8662 *** General Changes ***
  8663 
  8664 * hierachically structured name spaces (for consts, types, axms, thms
  8665 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  8666 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  8667 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  8668 long_names for fully qualified output names; NOTE: ML programs
  8669 (special tactics, packages etc.) referring to internal names may have
  8670 to be adapted to cope with fully qualified names; in case of severe
  8671 backward campatibility problems try setting 'global_names' at compile
  8672 time to have enrything declared within a flat name space; one may also
  8673 fine tune name declarations in theories via the 'global' and 'local'
  8674 section;
  8675 
  8676 * reimplemented the implicit simpset and claset using the new anytype
  8677 data filed in signatures; references simpset:simpset ref etc. are
  8678 replaced by functions simpset:unit->simpset and
  8679 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  8680 to patch your ML files accordingly;
  8681 
  8682 * HTML output now includes theory graph data for display with Java
  8683 applet or isatool browser; data generated automatically via isatool
  8684 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  8685 
  8686 * defs may now be conditional; improved rewrite_goals_tac to handle
  8687 conditional equations;
  8688 
  8689 * defs now admits additional type arguments, using TYPE('a) syntax;
  8690 
  8691 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  8692 creates a new theory node; implicit merge of thms' signatures is
  8693 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  8694 transfer:theory->thm->thm in (rare) cases;
  8695 
  8696 * improved handling of draft signatures / theories; draft thms (and
  8697 ctyps, cterms) are automatically promoted to real ones;
  8698 
  8699 * slightly changed interfaces for oracles: admit many per theory, named
  8700 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  8701 
  8702 * print_goals: optional output of const types (set show_consts and
  8703 show_types);
  8704 
  8705 * improved output of warnings (###) and errors (***);
  8706 
  8707 * subgoal_tac displays a warning if the new subgoal has type variables;
  8708 
  8709 * removed old README and Makefiles;
  8710 
  8711 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  8712 
  8713 * removed obsolete init_pps and init_database;
  8714 
  8715 * deleted the obsolete tactical STATE, which was declared by
  8716     fun STATE tacfun st = tacfun st st;
  8717 
  8718 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  8719 (which abbreviates $HOME);
  8720 
  8721 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  8722 use isatool fixseq to adapt your ML programs (this works for fully
  8723 qualified references to the Sequence structure only!);
  8724 
  8725 * use_thy no longer requires writable current directory; it always
  8726 reloads .ML *and* .thy file, if either one is out of date;
  8727 
  8728 
  8729 *** Classical Reasoner ***
  8730 
  8731 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  8732 tactics that use classical reasoning to simplify a subgoal without
  8733 splitting it into several subgoals;
  8734 
  8735 * Safe_tac: like safe_tac but uses the default claset;
  8736 
  8737 
  8738 *** Simplifier ***
  8739 
  8740 * added simplification meta rules:
  8741     (asm_)(full_)simplify: simpset -> thm -> thm;
  8742 
  8743 * simplifier.ML no longer part of Pure -- has to be loaded by object
  8744 logics (again);
  8745 
  8746 * added prems argument to simplification procedures;
  8747 
  8748 * HOL, FOL, ZF: added infix function `addsplits':
  8749   instead of `<simpset> setloop (split_tac <thms>)'
  8750   you can simply write `<simpset> addsplits <thms>'
  8751 
  8752 
  8753 *** Syntax ***
  8754 
  8755 * TYPE('a) syntax for type reflection terms;
  8756 
  8757 * no longer handles consts with name "" -- declare as 'syntax' instead;
  8758 
  8759 * pretty printer: changed order of mixfix annotation preference (again!);
  8760 
  8761 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  8762 
  8763 
  8764 *** HOL ***
  8765 
  8766 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8767   with `addloop' of the simplifier to faciliate case splitting in premises.
  8768 
  8769 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  8770 
  8771 * HOL/Auth: new protocol proofs including some for the Internet
  8772   protocol TLS;
  8773 
  8774 * HOL/Map: new theory of `maps' a la VDM;
  8775 
  8776 * HOL/simplifier: simplification procedures nat_cancel_sums for
  8777 cancelling out common nat summands from =, <, <= (in)equalities, or
  8778 differences; simplification procedures nat_cancel_factor for
  8779 cancelling common factor from =, <, <= (in)equalities over natural
  8780 sums; nat_cancel contains both kinds of procedures, it is installed by
  8781 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  8782 
  8783 * HOL/simplifier: terms of the form
  8784   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  8785   are rewritten to
  8786   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  8787   and those of the form
  8788   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  8789   are rewritten to
  8790   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  8791 
  8792 * HOL/datatype
  8793   Each datatype `t' now comes with a theorem `split_t_case' of the form
  8794 
  8795   P(t_case f1 ... fn x) =
  8796      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  8797         ...
  8798        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  8799      )
  8800 
  8801   and a theorem `split_t_case_asm' of the form
  8802 
  8803   P(t_case f1 ... fn x) =
  8804     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  8805         ...
  8806        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  8807      )
  8808   which can be added to a simpset via `addsplits'. The existing theorems
  8809   expand_list_case and expand_option_case have been renamed to
  8810   split_list_case and split_option_case.
  8811 
  8812 * HOL/Arithmetic:
  8813   - `pred n' is automatically converted to `n-1'.
  8814     Users are strongly encouraged not to use `pred' any longer,
  8815     because it will disappear altogether at some point.
  8816   - Users are strongly encouraged to write "0 < n" rather than
  8817     "n ~= 0". Theorems and proof tools have been modified towards this
  8818     `standard'.
  8819 
  8820 * HOL/Lists:
  8821   the function "set_of_list" has been renamed "set" (and its theorems too);
  8822   the function "nth" now takes its arguments in the reverse order and
  8823   has acquired the infix notation "!" as in "xs!n".
  8824 
  8825 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  8826 
  8827 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  8828   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  8829 
  8830 * HOL/record: extensible records with schematic structural subtyping
  8831 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  8832 still lacks various theorems and concrete record syntax;
  8833 
  8834 
  8835 *** HOLCF ***
  8836 
  8837 * removed "axioms" and "generated by" sections;
  8838 
  8839 * replaced "ops" section by extended "consts" section, which is capable of
  8840   handling the continuous function space "->" directly;
  8841 
  8842 * domain package:
  8843   . proves theorems immediately and stores them in the theory,
  8844   . creates hierachical name space,
  8845   . now uses normal mixfix annotations (instead of cinfix...),
  8846   . minor changes to some names and values (for consistency),
  8847   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  8848   . separator between mutual domain defs: changed "," to "and",
  8849   . improved handling of sort constraints;  now they have to
  8850     appear on the left-hand side of the equations only;
  8851 
  8852 * fixed LAM <x,y,zs>.b syntax;
  8853 
  8854 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  8855 adm (%x. P (t x)), where P is chainfinite and t continuous;
  8856 
  8857 
  8858 *** FOL and ZF ***
  8859 
  8860 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8861   with `addloop' of the simplifier to faciliate case splitting in premises.
  8862 
  8863 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8864 in HOL, they strip ALL and --> from proved theorems;
  8865 
  8866 
  8867 
  8868 New in Isabelle94-8 (May 1997)
  8869 ------------------------------
  8870 
  8871 *** General Changes ***
  8872 
  8873 * new utilities to build / run / maintain Isabelle etc. (in parts
  8874 still somewhat experimental); old Makefiles etc. still functional;
  8875 
  8876 * new 'Isabelle System Manual';
  8877 
  8878 * INSTALL text, together with ./configure and ./build scripts;
  8879 
  8880 * reimplemented type inference for greater efficiency, better error
  8881 messages and clean internal interface;
  8882 
  8883 * prlim command for dealing with lots of subgoals (an easier way of
  8884 setting goals_limit);
  8885 
  8886 
  8887 *** Syntax ***
  8888 
  8889 * supports alternative (named) syntax tables (parser and pretty
  8890 printer); internal interface is provided by add_modesyntax(_i);
  8891 
  8892 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8893 be used in conjunction with the Isabelle symbol font; uses the
  8894 "symbols" syntax table;
  8895 
  8896 * added token_translation interface (may translate name tokens in
  8897 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8898 the current print_mode); IMPORTANT: user print translation functions
  8899 are responsible for marking newly introduced bounds
  8900 (Syntax.mark_boundT);
  8901 
  8902 * token translations for modes "xterm" and "xterm_color" that display
  8903 names in bold, underline etc. or colors (which requires a color
  8904 version of xterm);
  8905 
  8906 * infixes may now be declared with names independent of their syntax;
  8907 
  8908 * added typed_print_translation (like print_translation, but may
  8909 access type of constant);
  8910 
  8911 
  8912 *** Classical Reasoner ***
  8913 
  8914 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8915 some limitations.  Blast_tac...
  8916   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8917   + ignores elimination rules that don't have the correct format
  8918         (the conclusion MUST be a formula variable)
  8919   + ignores types, which can make HOL proofs fail
  8920   + rules must not require higher-order unification, e.g. apply_type in ZF
  8921     [message "Function Var's argument not a bound variable" relates to this]
  8922   + its proof strategy is more general but can actually be slower
  8923 
  8924 * substitution with equality assumptions no longer permutes other
  8925 assumptions;
  8926 
  8927 * minor changes in semantics of addafter (now called addaltern); renamed
  8928 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8929 (and access functions for it);
  8930 
  8931 * improved combination of classical reasoner and simplifier:
  8932   + functions for handling clasimpsets
  8933   + improvement of addss: now the simplifier is called _after_ the
  8934     safe steps.
  8935   + safe variant of addss called addSss: uses safe simplifications
  8936     _during_ the safe steps. It is more complete as it allows multiple
  8937     instantiations of unknowns (e.g. with slow_tac).
  8938 
  8939 *** Simplifier ***
  8940 
  8941 * added interface for simplification procedures (functions that
  8942 produce *proven* rewrite rules on the fly, depending on current
  8943 redex);
  8944 
  8945 * ordering on terms as parameter (used for ordered rewriting);
  8946 
  8947 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8948 
  8949 * the solver is now split into a safe and an unsafe part.
  8950 This should be invisible for the normal user, except that the
  8951 functions setsolver and addsolver have been renamed to setSolver and
  8952 addSolver; added safe_asm_full_simp_tac;
  8953 
  8954 
  8955 *** HOL ***
  8956 
  8957 * a generic induction tactic `induct_tac' which works for all datatypes and
  8958 also for type `nat';
  8959 
  8960 * a generic case distinction tactic `exhaust_tac' which works for all
  8961 datatypes and also for type `nat';
  8962 
  8963 * each datatype comes with a function `size';
  8964 
  8965 * patterns in case expressions allow tuple patterns as arguments to
  8966 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8967 
  8968 * primrec now also works with type nat;
  8969 
  8970 * recdef: a new declaration form, allows general recursive functions to be
  8971 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8972 
  8973 * the constant for negation has been renamed from "not" to "Not" to
  8974 harmonize with FOL, ZF, LK, etc.;
  8975 
  8976 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8977 infinite lists;
  8978 
  8979 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8980 
  8981 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8982 problems in commutative rings, using axiomatic type classes for + and *;
  8983 
  8984 * more examples in HOL/MiniML and HOL/Auth;
  8985 
  8986 * more default rewrite rules for quantifiers, union/intersection;
  8987 
  8988 * a new constant `arbitrary == @x.False';
  8989 
  8990 * HOLCF/IOA replaces old HOL/IOA;
  8991 
  8992 * HOLCF changes: derived all rules and arities
  8993   + axiomatic type classes instead of classes
  8994   + typedef instead of faking type definitions
  8995   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8996   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8997   + eliminated the types void, one, tr
  8998   + use unit lift and bool lift (with translations) instead of one and tr
  8999   + eliminated blift from Lift3.thy (use Def instead of blift)
  9000   all eliminated rules are derived as theorems --> no visible changes ;
  9001 
  9002 
  9003 *** ZF ***
  9004 
  9005 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  9006 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  9007 as ZF_cs addSIs [equalityI];
  9008 
  9009 
  9010 
  9011 New in Isabelle94-7 (November 96)
  9012 ---------------------------------
  9013 
  9014 * allowing negative levels (as offsets) in prlev and choplev;
  9015 
  9016 * super-linear speedup for large simplifications;
  9017 
  9018 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  9019 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  9020 FAIL); can suppress it using the command Delsimps (ex_simps @
  9021 all_simps); De Morgan laws are also now included, by default;
  9022 
  9023 * improved printing of ==>  :  ~:
  9024 
  9025 * new object-logic "Sequents" adds linear logic, while replacing LK
  9026 and Modal (thanks to Sara Kalvala);
  9027 
  9028 * HOL/Auth: correctness proofs for authentication protocols;
  9029 
  9030 * HOL: new auto_tac combines rewriting and classical reasoning (many
  9031 examples on HOL/Auth);
  9032 
  9033 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  9034 the rewriter and classical reasoner simultaneously;
  9035 
  9036 * function uresult no longer returns theorems in "standard" format;
  9037 regain previous version by: val uresult = standard o uresult;
  9038 
  9039 
  9040 
  9041 New in Isabelle94-6
  9042 -------------------
  9043 
  9044 * oracles -- these establish an interface between Isabelle and trusted
  9045 external reasoners, which may deliver results as theorems;
  9046 
  9047 * proof objects (in particular record all uses of oracles);
  9048 
  9049 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  9050 
  9051 * "constdefs" section in theory files;
  9052 
  9053 * "primrec" section (HOL) no longer requires names;
  9054 
  9055 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  9056 
  9057 
  9058 
  9059 New in Isabelle94-5
  9060 -------------------
  9061 
  9062 * reduced space requirements;
  9063 
  9064 * automatic HTML generation from theories;
  9065 
  9066 * theory files no longer require "..." (quotes) around most types;
  9067 
  9068 * new examples, including two proofs of the Church-Rosser theorem;
  9069 
  9070 * non-curried (1994) version of HOL is no longer distributed;
  9071 
  9072 
  9073 
  9074 New in Isabelle94-4
  9075 -------------------
  9076 
  9077 * greatly reduced space requirements;
  9078 
  9079 * theory files (.thy) no longer require \...\ escapes at line breaks;
  9080 
  9081 * searchable theorem database (see the section "Retrieving theorems" on
  9082 page 8 of the Reference Manual);
  9083 
  9084 * new examples, including Grabczewski's monumental case study of the
  9085 Axiom of Choice;
  9086 
  9087 * The previous version of HOL renamed to Old_HOL;
  9088 
  9089 * The new version of HOL (previously called CHOL) uses a curried syntax
  9090 for functions.  Application looks like f a b instead of f(a,b);
  9091 
  9092 * Mutually recursive inductive definitions finally work in HOL;
  9093 
  9094 * In ZF, pattern-matching on tuples is now available in all abstractions and
  9095 translates to the operator "split";
  9096 
  9097 
  9098 
  9099 New in Isabelle94-3
  9100 -------------------
  9101 
  9102 * new infix operator, addss, allowing the classical reasoner to
  9103 perform simplification at each step of its search.  Example:
  9104         fast_tac (cs addss ss)
  9105 
  9106 * a new logic, CHOL, the same as HOL, but with a curried syntax
  9107 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  9108 look like (a,b) instead of <a,b>;
  9109 
  9110 * PLEASE NOTE: CHOL will eventually replace HOL!
  9111 
  9112 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  9113 It translates to the operator "split".  A new theory of integers is available;
  9114 
  9115 * In ZF, integer numerals now denote two's-complement binary integers.
  9116 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  9117 
  9118 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  9119 of the Axiom of Choice;
  9120 
  9121 
  9122 
  9123 New in Isabelle94-2
  9124 -------------------
  9125 
  9126 * Significantly faster resolution;
  9127 
  9128 * the different sections in a .thy file can now be mixed and repeated
  9129 freely;
  9130 
  9131 * Database of theorems for FOL, HOL and ZF.  New
  9132 commands including qed, qed_goal and bind_thm store theorems in the database.
  9133 
  9134 * Simple database queries: return a named theorem (get_thm) or all theorems of
  9135 a given theory (thms_of), or find out what theory a theorem was proved in
  9136 (theory_of_thm);
  9137 
  9138 * Bugs fixed in the inductive definition and datatype packages;
  9139 
  9140 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  9141 and HOL_dup_cs obsolete;
  9142 
  9143 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  9144 have been removed;
  9145 
  9146 * Simpler definition of function space in ZF;
  9147 
  9148 * new results about cardinal and ordinal arithmetic in ZF;
  9149 
  9150 * 'subtype' facility in HOL for introducing new types as subsets of existing
  9151 types;
  9152 
  9153 :mode=text:wrap=hard:maxLineLen=72: