NEWS
author wenzelm
Sun Jun 08 14:31:06 2008 +0200 (2008-06-08)
changeset 27094 2cf13a72e170
parent 27067 f8a7aff41acb
child 27104 791607529f6d
permissions -rw-r--r--
updated generated file;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2008 (June 2008)
     5 -------------------------------
     6 
     7 *** General ***
     8 
     9 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
    10 and updated, with formally checked references as hyperlinks.
    11 
    12 * Theory loader: use_thy (and similar operations) no longer set the
    13 implicit ML context, which was occasionally hard to predict and in
    14 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
    15 provides a proper context already.
    16 
    17 * Theory loader: old-style ML proof scripts being *attached* to a thy
    18 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
    19 'use' within a theory file will do the job.
    20 
    21 * Name space merge now observes canonical order, i.e. the second space
    22 is inserted into the first one, while existing entries in the first
    23 space take precedence.  INCOMPATIBILITY in rare situations, may try to
    24 swap theory imports.
    25 
    26 * Syntax: symbol \<chi> is now considered a letter.  Potential
    27 INCOMPATIBILITY in identifier syntax etc.
    28 
    29 * Outer syntax: string tokens no longer admit escaped white space,
    30 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
    31 white space without escapes.
    32 
    33 * Outer syntax: string tokens may contain arbitrary character codes
    34 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
    35 "foo_bar".
    36 
    37 
    38 *** Pure ***
    39 
    40 * Context-dependent token translations.  Default setup reverts locally
    41 fixed variables, and adds hilite markup for undeclared frees.
    42 
    43 * Unused theorems can be found using the new command 'unused_thms'.
    44 There are three ways of invoking it:
    45 
    46 (1) unused_thms
    47      Only finds unused theorems in the current theory.
    48 
    49 (2) unused_thms thy_1 ... thy_n -
    50      Finds unused theorems in the current theory and all of its ancestors,
    51      excluding the theories thy_1 ... thy_n and all of their ancestors.
    52 
    53 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
    54      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
    55      their ancestors, excluding the theories thy_1 ... thy_n and all of
    56      their ancestors.
    57 
    58 In order to increase the readability of the list produced by
    59 unused_thms, theorems that have been created by a particular instance
    60 of a theory command such as 'inductive' or 'function' are considered
    61 to belong to the same "group", meaning that if at least one theorem in
    62 this group is used, the other theorems in the same group are no longer
    63 reported as unused.  Moreover, if all theorems in the group are
    64 unused, only one theorem in the group is displayed.
    65 
    66 Note that proof objects have to be switched on in order for
    67 unused_thms to work properly (i.e. !proofs must be >= 1, which is
    68 usually the case when using Proof General with the default settings).
    69 
    70 * Authentic naming of facts disallows ad-hoc overwriting of previous
    71 theorems within the same name space.  INCOMPATIBILITY, need to remove
    72 duplicate fact bindings, or even accidental fact duplications.  Note
    73 that tools may maintain dynamically scoped facts systematically, using
    74 PureThy.add_thms_dynamic.
    75 
    76 * Command 'hide' now allows to hide from "fact" name space as well.
    77 
    78 * Eliminated destructive theorem database, simpset, claset, and
    79 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
    80 update of theories within ML code.
    81 
    82 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
    83 INCOMPATIBILITY, object-logics depending on former Pure require
    84 additional setup PureThy.old_appl_syntax_setup; object-logics
    85 depending on former CPure need to refer to Pure.
    86 
    87 * Commands 'use' and 'ML' are now purely functional, operating on
    88 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
    89 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
    90 INCOMPATIBILITY.
    91 
    92 * Command 'setup': discontinued implicit version with ML reference.
    93 
    94 * Instantiation target allows for simultaneous specification of class
    95 instance operations together with an instantiation proof.
    96 Type-checking phase allows to refer to class operations uniformly.
    97 See src/HOL/Complex/Complex.thy for an Isar example and
    98 src/HOL/Library/Eval.thy for an ML example.
    99 
   100 * Indexing of literal facts: be more serious about including only
   101 facts from the visible specification/proof context, but not the
   102 background context (locale etc.).  Affects `prop` notation and method
   103 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   104 situations.
   105 
   106 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   107 "(open)" option, which used to expose internal bound variables to the
   108 proof text.
   109 
   110 * Isar statements: removed obsolete case "rule_context".
   111 INCOMPATIBILITY, better use explicit fixes/assumes.
   112 
   113 * Locale proofs: default proof step now includes 'unfold_locales';
   114 hence 'proof' without argument may be used to unfold locale
   115 predicates.
   116 
   117 
   118 *** Document preparation ***
   119 
   120 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   121 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   122 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   123 spot); renamed link color from "darkblue" to "linkcolor" (default
   124 value unchanged, can be redefined via \definecolor); no longer sets
   125 "a4paper" option (unnecessary or even intrusive).
   126 
   127 * Antiquotation @{lemma A method} proves proposition A by the given
   128 method (either a method name or a method name plus (optional) method
   129 arguments in parentheses) and prints A just like @{prop A}.
   130 
   131 
   132 *** HOL ***
   133 
   134 * New primrec package.  Specification syntax conforms in style to
   135 definition/function/....  No separate induction rule is provided.  The
   136 "primrec" command distinguishes old-style and new-style specifications
   137 by syntax.  The former primrec package is now named OldPrimrecPackage.
   138 When adjusting theories, beware: constants stemming from new-style
   139 primrec specifications have authentic syntax.
   140 
   141 * Metis prover is now an order of magnitude faster, and also works
   142 with multithreading.
   143 
   144 * Metis: the maximum number of clauses that can be produced from a
   145 theorem is now given by the attribute max_clauses.  Theorems that
   146 exceed this number are ignored, with a warning printed.
   147 
   148 * Sledgehammer no longer produces structured proofs by default. To
   149 enable, declare [[sledgehammer_full = true]].  Attributes
   150 reconstruction_modulus, reconstruction_sorts renamed
   151 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   152 
   153 * Method "induction_scheme" derives user-specified induction rules
   154 from well-founded induction and completeness of patterns. This factors
   155 out some operations that are done internally by the function package
   156 and makes them available separately.  See
   157 src/HOL/ex/Induction_Scheme.thy for examples.
   158 
   159 * More flexible generation of measure functions for termination
   160 proofs: Measure functions can be declared by proving a rule of the
   161 form "is_measure f" and giving it the [measure_function] attribute.
   162 The "is_measure" predicate is logically meaningless (always true), and
   163 just guides the heuristic.  To find suitable measure functions, the
   164 termination prover sets up the goal "is_measure ?f" of the appropriate
   165 type and generates all solutions by prolog-style backwards proof using
   166 the declared rules.
   167 
   168 This setup also deals with rules like 
   169 
   170   "is_measure f ==> is_measure (list_size f)"
   171 
   172 which accommodates nested datatypes that recurse through lists.
   173 Similar rules are predeclared for products and option types.
   174 
   175 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   176 
   177   INCOMPATIBILITIES:
   178 
   179   - Definitions of overloaded constants on sets have to be replaced by
   180     definitions on => and bool.
   181 
   182   - Some definitions of overloaded operators on sets can now be proved
   183     using the definitions of the operators on => and bool.  Therefore,
   184     the following theorems have been renamed:
   185 
   186       subset_def   -> subset_eq
   187       psubset_def  -> psubset_eq
   188       set_diff_def -> set_diff_eq
   189       Compl_def    -> Compl_eq
   190       Sup_set_def  -> Sup_set_eq
   191       Inf_set_def  -> Inf_set_eq
   192       sup_set_def  -> sup_set_eq
   193       inf_set_def  -> inf_set_eq
   194 
   195   - Due to the incompleteness of the HO unification algorithm, some
   196     rules such as subst may require manual instantiation, if some of
   197     the unknowns in the rule is a set.
   198 
   199   - Higher order unification and forward proofs:
   200     The proof pattern
   201 
   202       have "P (S::'a set)" <...>
   203       then have "EX S. P S" ..
   204 
   205     no longer works (due to the incompleteness of the HO unification
   206     algorithm) and must be replaced by the pattern
   207 
   208       have "EX S. P S"
   209       proof
   210         show "P S" <...>
   211       qed
   212 
   213   - Calculational reasoning with subst (or similar rules):
   214     The proof pattern
   215 
   216       have "P (S::'a set)" <...>
   217       also have "S = T" <...>
   218       finally have "P T" .
   219 
   220     no longer works (for similar reasons as the previous example) and
   221     must be replaced by something like
   222 
   223       have "P (S::'a set)" <...>
   224       moreover have "S = T" <...>
   225       ultimately have "P T" by simp
   226 
   227   - Tactics or packages written in ML code:
   228     Code performing pattern matching on types via
   229 
   230       Type ("set", [T]) => ...
   231 
   232     must be rewritten. Moreover, functions like strip_type or
   233     binder_types no longer return the right value when applied to a
   234     type of the form
   235 
   236       T1 => ... => Tn => U => bool
   237 
   238     rather than
   239 
   240       T1 => ... => Tn => U set
   241 
   242 * Merged theories Wellfounded_Recursion, Accessible_Part and
   243 Wellfounded_Relations to theory Wellfounded.
   244 
   245 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   246 
   247 * Class finite no longer treats UNIV as class parameter.  Use class
   248 enum from theory Library/Enum instead to achieve a similar effect.
   249 INCOMPATIBILITY.
   250 
   251 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   252 and "Cons".  INCOMPATIBILITY.
   253 
   254 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   255 Potential INCOMPATIBILITY.
   256 
   257 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   258 injective_fst_snd removed, use split_eta and prod_eqI instead.
   259 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   260 
   261 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   262 the same name in theory Orderings:
   263 
   264   less_trans
   265   less_linear
   266   le_imp_less_or_eq
   267   le_less_trans
   268   less_le_trans
   269   less_not_sym
   270   less_asym
   271 
   272 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   273 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   274 and different variable names.
   275 
   276 * Library/Option_ord.thy: Canonical order on option type.
   277 
   278 * Library/RBT.thy: Red-black trees, an efficient implementation of
   279 finite maps.
   280 
   281 * Library/Countable.thy: Type class for countable types.
   282 
   283 * Theory Int: The representation of numerals has changed.  The infix
   284 operator BIT and the bit datatype with constructors B0 and B1 have
   285 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   286 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   287 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   288 accordingly.
   289 
   290 * Theory Nat: definition of <= and < on natural numbers no longer
   291 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   292 le_def and less_def have disappeared.  Consider lemmas not_less
   293 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   294 
   295 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   296 (whose purpose mainly is for various fold_set functionals) have been
   297 abandoned in favor of the existing algebraic classes
   298 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   299 lower_semilattice (resp. upper_semilattice) and linorder.
   300 INCOMPATIBILITY.
   301 
   302 * Theory Transitive_Closure: induct and cases rules now declare proper
   303 case_names ("base" and "step").  INCOMPATIBILITY.
   304 
   305 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   306 lattices.  The form set-specific version is available as
   307 Inductive.lfp_ordinal_induct_set.
   308 
   309 * Renamed theorems "power.simps" to "power_int.simps".
   310 INCOMPATIBILITY.
   311 
   312 * Class semiring_div provides basic abstract properties of semirings
   313 with division and modulo operations.  Subsumes former class dvd_mod.
   314 
   315 * Merged theories IntDef, Numeral and IntArith into unified theory
   316 Int.  INCOMPATIBILITY.
   317 
   318 * Theory Library/Code_Index: type "index" now represents natural
   319 numbers rather than integers.  INCOMPATIBILITY.
   320 
   321 * New class "uminus" with operation "uminus" (split of from class
   322 "minus" which now only has operation "minus", binary).
   323 INCOMPATIBILITY.
   324 
   325 * Constants "card", "internal_split", "option_map" now with authentic
   326 syntax.  INCOMPATIBILITY.
   327 
   328 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   329 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   330 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   331 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   332 Sup_set_def, le_def, less_def, option_map_def now with object
   333 equality.  INCOMPATIBILITY.
   334 
   335 * Records. Removed K_record, and replaced it by pure lambda term
   336 %x. c. The simplifier setup is now more robust against eta expansion.
   337 INCOMPATIBILITY: in cases explicitly referring to K_record.
   338 
   339 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   340 
   341 * Library/ListVector: new theory of arithmetic vector operations.
   342 
   343 * Library/Order_Relation: new theory of various orderings as sets of
   344 pairs.  Defines preorders, partial orders, linear orders and
   345 well-orders on sets and on types.
   346 
   347 
   348 *** ZF ***
   349 
   350 * Renamed some theories to allow to loading both ZF and HOL in the
   351 same session:
   352 
   353   Datatype  -> Datatype_ZF
   354   Inductive -> Inductive_ZF
   355   Int       -> Int_ZF
   356   IntDiv    -> IntDiv_ZF
   357   Nat       -> Nat_ZF
   358   List      -> List_ZF
   359   Main      -> Main_ZF
   360 
   361 INCOMPATIBILITY: ZF theories that import individual theories below
   362 Main might need to be adapted.  Regular theory Main is still
   363 available, as trivial extension of Main_ZF.
   364 
   365 
   366 *** ML ***
   367 
   368 * ML within Isar: antiquotation @{const name} or @{const
   369 name(typargs)} produces statically-checked Const term.
   370 
   371 * Functor NamedThmsFun: data is available to the user as dynamic fact
   372 (of the same name).  Removed obsolete print command.
   373 
   374 * Removed obsolete "use_legacy_bindings" function.
   375 
   376 * The ``print mode'' is now a thread-local value derived from a global
   377 template (the former print_mode reference), thus access becomes
   378 non-critical.  The global print_mode reference is for session
   379 management only; user-code should use print_mode_value,
   380 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   381 
   382 * Functions system/system_out provide a robust way to invoke external
   383 shell commands, with propagation of interrupts (requires Poly/ML 5.2).
   384 Do not use OS.Process.system etc. from the basis library!
   385 
   386 
   387 *** System ***
   388 
   389 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   390 in accordance with Proof General 3.7, which prefers GNU emacs.
   391 
   392 * isatool tty runs Isabelle process with plain tty interaction;
   393 optional line editor may be specified via ISABELLE_LINE_EDITOR
   394 setting, the default settings attempt to locate "ledit" and "rlwrap".
   395 
   396 * isatool browser now works with Cygwin as well, using general
   397 "javapath" function defined in Isabelle process environment.
   398 
   399 * YXML notation provides a simple and efficient alternative to
   400 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   401 isatool yxml as described in the Isabelle system manual.
   402 
   403 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   404 provides general wrapper for managing an Isabelle process in a robust
   405 fashion, with ``cooked'' output from stdin/stderr.
   406 
   407 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   408 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   409 
   410 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   411 way of changing the user's settings is via
   412 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   413 script.
   414 
   415 * Multithreading.max_threads := 0 refers to the number of actual CPU
   416 cores of the underlying machine, which is a good starting point for
   417 optimal performance tuning.  The corresponding usedir option -M allows
   418 "max" as an alias for "0".  WARNING: does not work on certain versions
   419 of Mac OS (with Poly/ML 5.1).
   420 
   421 * isabelle-process: non-ML sessions are run with "nice", to reduce the
   422 adverse effect of Isabelle flooding interactive front-ends (notably
   423 ProofGeneral / XEmacs).
   424 
   425 
   426 
   427 New in Isabelle2007 (November 2007)
   428 -----------------------------------
   429 
   430 *** General ***
   431 
   432 * More uniform information about legacy features, notably a
   433 warning/error of "Legacy feature: ...", depending on the state of the
   434 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   435 legacy features will disappear eventually.
   436 
   437 * Theory syntax: the header format ``theory A = B + C:'' has been
   438 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   439 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   440 
   441 * Theory syntax: the old non-Isar theory file format has been
   442 discontinued altogether.  Note that ML proof scripts may still be used
   443 with Isar theories; migration is usually quite simple with the ML
   444 function use_legacy_bindings.  INCOMPATIBILITY.
   445 
   446 * Theory syntax: some popular names (e.g. 'class', 'declaration',
   447 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
   448 quotes.
   449 
   450 * Theory loader: be more serious about observing the static theory
   451 header specifications (including optional directories), but not the
   452 accidental file locations of previously successful loads.  The strict
   453 update policy of former update_thy is now already performed by
   454 use_thy, so the former has been removed; use_thys updates several
   455 theories simultaneously, just as 'imports' within a theory header
   456 specification, but without merging the results.  Potential
   457 INCOMPATIBILITY: may need to refine theory headers and commands
   458 ROOT.ML which depend on load order.
   459 
   460 * Theory loader: optional support for content-based file
   461 identification, instead of the traditional scheme of full physical
   462 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
   463 (cf. the system manual).  The new scheme allows to work with
   464 non-finished theories in persistent session images, such that source
   465 files may be moved later on without requiring reloads.
   466 
   467 * Theory loader: old-style ML proof scripts being *attached* to a thy
   468 file (with the same base name as the theory) are considered a legacy
   469 feature, which will disappear eventually. Even now, the theory loader
   470 no longer maintains dependencies on such files.
   471 
   472 * Syntax: the scope for resolving ambiguities via type-inference is
   473 now limited to individual terms, instead of whole simultaneous
   474 specifications as before. This greatly reduces the complexity of the
   475 syntax module and improves flexibility by separating parsing and
   476 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
   477 'fixes' etc.) are required in rare situations.
   478 
   479 * Syntax: constants introduced by new-style packages ('definition',
   480 'abbreviation' etc.) are passed through the syntax module in
   481 ``authentic mode''. This means that associated mixfix annotations
   482 really stick to such constants, independently of potential name space
   483 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   484 trees are represented slightly differently, may need to adapt syntax
   485 translations accordingly. Use CONST marker in 'translations' and
   486 @{const_syntax} antiquotation in 'parse_translation' etc.
   487 
   488 * Legacy goal package: reduced interface to the bare minimum required
   489 to keep existing proof scripts running.  Most other user-level
   490 functions are now part of the OldGoals structure, which is *not* open
   491 by default (consider isatool expandshort before open OldGoals).
   492 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   493 these tend to cause confusion about the actual goal (!) context being
   494 used here, which is not necessarily the same as the_context().
   495 
   496 * Command 'find_theorems': supports "*" wild-card in "name:"
   497 criterion; "with_dups" option.  Certain ProofGeneral versions might
   498 support a specific search form (see ProofGeneral/CHANGES).
   499 
   500 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   501 by default, which means that "prems" (and also "fixed variables") are
   502 suppressed from proof state output.  Note that the ProofGeneral
   503 settings mechanism allows to change and save options persistently, but
   504 older versions of Isabelle will fail to start up if a negative prems
   505 limit is imposed.
   506 
   507 * Local theory targets may be specified by non-nested blocks of
   508 ``context/locale/class ... begin'' followed by ``end''.  The body may
   509 contain definitions, theorems etc., including any derived mechanism
   510 that has been implemented on top of these primitives.  This concept
   511 generalizes the existing ``theorem (in ...)'' towards more versatility
   512 and scalability.
   513 
   514 * Proof General interface: proper undo of final 'end' command;
   515 discontinued Isabelle/classic mode (ML proof scripts).
   516 
   517 
   518 *** Document preparation ***
   519 
   520 * Added antiquotation @{theory name} which prints the given name,
   521 after checking that it refers to a valid ancestor theory in the
   522 current context.
   523 
   524 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   525 check the given source text as ML type/structure, printing verbatim.
   526 
   527 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   528 "c args == rhs" given in the current context.  (Any number of
   529 arguments may be given on the LHS.)
   530 
   531 
   532 *** Pure ***
   533 
   534 * The 'class' package offers a combination of axclass and locale to
   535 achieve Haskell-like type classes in Isabelle.  Definitions and
   536 theorems within a class context produce both relative results (with
   537 implicit parameters according to the locale context), and polymorphic
   538 constants with qualified polymorphism (according to the class
   539 context).  Within the body context of a 'class' target, a separate
   540 syntax layer ("user space type system") takes care of converting
   541 between global polymorphic consts and internal locale representation.
   542 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   543 "isatool doc classes" provides a tutorial.
   544 
   545 * Generic code generator framework allows to generate executable
   546 code for ML and Haskell (including Isabelle classes).  A short usage
   547 sketch:
   548 
   549     internal compilation:
   550         export_code <list of constants (term syntax)> in SML
   551     writing SML code to a file:
   552         export_code <list of constants (term syntax)> in SML <filename>
   553     writing OCaml code to a file:
   554         export_code <list of constants (term syntax)> in OCaml <filename>
   555     writing Haskell code to a bunch of files:
   556         export_code <list of constants (term syntax)> in Haskell <filename>
   557 
   558     evaluating closed propositions to True/False using code generation:
   559         method ``eval''
   560 
   561 Reasonable default setup of framework in HOL.
   562 
   563 Theorem attributs for selecting and transforming function equations theorems:
   564 
   565     [code fun]:        select a theorem as function equation for a specific constant
   566     [code fun del]:    deselect a theorem as function equation for a specific constant
   567     [code inline]:     select an equation theorem for unfolding (inlining) in place
   568     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   569 
   570 User-defined serializations (target in {SML, OCaml, Haskell}):
   571 
   572     code_const <and-list of constants (term syntax)>
   573       {(target) <and-list of const target syntax>}+
   574 
   575     code_type <and-list of type constructors>
   576       {(target) <and-list of type target syntax>}+
   577 
   578     code_instance <and-list of instances>
   579       {(target)}+
   580         where instance ::= <type constructor> :: <class>
   581 
   582     code_class <and_list of classes>
   583       {(target) <and-list of class target syntax>}+
   584         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   585 
   586 code_instance and code_class only are effective to target Haskell.
   587 
   588 For example usage see src/HOL/ex/Codegenerator.thy and
   589 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   590 generation from Isabelle/HOL theories is available via "isatool doc
   591 codegen".
   592 
   593 * Code generator: consts in 'consts_code' Isar commands are now
   594 referred to by usual term syntax (including optional type
   595 annotations).
   596 
   597 * Command 'no_translations' removes translation rules from theory
   598 syntax.
   599 
   600 * Overloaded definitions are now actually checked for acyclic
   601 dependencies.  The overloading scheme is slightly more general than
   602 that of Haskell98, although Isabelle does not demand an exact
   603 correspondence to type class and instance declarations.
   604 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   605 exotic versions of overloading -- at the discretion of the user!
   606 
   607 Polymorphic constants are represented via type arguments, i.e. the
   608 instantiation that matches an instance against the most general
   609 declaration given in the signature.  For example, with the declaration
   610 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   611 as c(nat).  Overloading is essentially simultaneous structural
   612 recursion over such type arguments.  Incomplete specification patterns
   613 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   614 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   615 Command 'print_theory' outputs the normalized system of recursive
   616 equations, see section "definitions".
   617 
   618 * Configuration options are maintained within the theory or proof
   619 context (with name and type bool/int/string), providing a very simple
   620 interface to a poor-man's version of general context data.  Tools may
   621 declare options in ML (e.g. using Attrib.config_int) and then refer to
   622 these values using Config.get etc.  Users may change options via an
   623 associated attribute of the same name.  This form of context
   624 declaration works particularly well with commands 'declare' or
   625 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   626 very easy to avoid global references, which would not observe Isar
   627 toplevel undo/redo and fail to work with multithreading.
   628 
   629 Various global ML references of Pure and HOL have been turned into
   630 configuration options:
   631 
   632   Unify.search_bound		unify_search_bound
   633   Unify.trace_bound		unify_trace_bound
   634   Unify.trace_simp		unify_trace_simp
   635   Unify.trace_types		unify_trace_types
   636   Simplifier.simp_depth_limit	simp_depth_limit
   637   Blast.depth_limit		blast_depth_limit
   638   DatatypeProp.dtK		datatype_distinctness_limit
   639   fast_arith_neq_limit  	fast_arith_neq_limit
   640   fast_arith_split_limit	fast_arith_split_limit
   641 
   642 * Named collections of theorems may be easily installed as context
   643 data using the functor NamedThmsFun (see also
   644 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   645 attributes; there is also a toplevel print command.  This facility is
   646 just a common case of general context data, which is the preferred way
   647 for anything more complex than just a list of facts in canonical
   648 order.
   649 
   650 * Isar: command 'declaration' augments a local theory by generic
   651 declaration functions written in ML.  This enables arbitrary content
   652 being added to the context, depending on a morphism that tells the
   653 difference of the original declaration context wrt. the application
   654 context encountered later on.
   655 
   656 * Isar: proper interfaces for simplification procedures.  Command
   657 'simproc_setup' declares named simprocs (with match patterns, and body
   658 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   659 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   660 
   661 * Isar: an extra pair of brackets around attribute declarations
   662 abbreviates a theorem reference involving an internal dummy fact,
   663 which will be ignored later --- only the effect of the attribute on
   664 the background context will persist.  This form of in-place
   665 declarations is particularly useful with commands like 'declare' and
   666 'using', for example ``have A using [[simproc a]] by simp''.
   667 
   668 * Isar: method "assumption" (and implicit closing of subproofs) now
   669 takes simple non-atomic goal assumptions into account: after applying
   670 an assumption as a rule the resulting subgoals are solved by atomic
   671 assumption steps.  This is particularly useful to finish 'obtain'
   672 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   673 without referring to the original premise "!!x. P x ==> thesis" in the
   674 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   675 more permissive.
   676 
   677 * Isar: implicit use of prems from the Isar proof context is
   678 considered a legacy feature.  Common applications like ``have A .''
   679 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   680 referencing facts explicitly here improves readability and
   681 maintainability of proof texts.
   682 
   683 * Isar: improper proof element 'guess' is like 'obtain', but derives
   684 the obtained context from the course of reasoning!  For example:
   685 
   686   assume "EX x y. A x & B y"   -- "any previous fact"
   687   then guess x and y by clarify
   688 
   689 This technique is potentially adventurous, depending on the facts and
   690 proof tools being involved here.
   691 
   692 * Isar: known facts from the proof context may be specified as literal
   693 propositions, using ASCII back-quote syntax.  This works wherever
   694 named facts used to be allowed so far, in proof commands, proof
   695 methods, attributes etc.  Literal facts are retrieved from the context
   696 according to unification of type and term parameters.  For example,
   697 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   698 theorems in the current context, then these are valid literal facts:
   699 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   700 
   701 There is also a proof method "fact" which does the same composition
   702 for explicit goal states, e.g. the following proof texts coincide with
   703 certain special cases of literal facts:
   704 
   705   have "A" by fact                 ==  note `A`
   706   have "A ==> B" by fact           ==  note `A ==> B`
   707   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   708   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   709 
   710 * Isar: ":" (colon) is no longer a symbolic identifier character in
   711 outer syntax.  Thus symbolic identifiers may be used without
   712 additional white space in declarations like this: ``assume *: A''.
   713 
   714 * Isar: 'print_facts' prints all local facts of the current context,
   715 both named and unnamed ones.
   716 
   717 * Isar: 'def' now admits simultaneous definitions, e.g.:
   718 
   719   def x == "t" and y == "u"
   720 
   721 * Isar: added command 'unfolding', which is structurally similar to
   722 'using', but affects both the goal state and facts by unfolding given
   723 rewrite rules.  Thus many occurrences of the 'unfold' method or
   724 'unfolded' attribute may be replaced by first-class proof text.
   725 
   726 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   727 and command 'unfolding' now all support object-level equalities
   728 (potentially conditional).  The underlying notion of rewrite rule is
   729 analogous to the 'rule_format' attribute, but *not* that of the
   730 Simplifier (which is usually more generous).
   731 
   732 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   733 premises of a theorem by n. Useful in conjunction with drule.
   734 
   735 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   736 method expression within a sandbox consisting of the first N
   737 sub-goals, which need to exist.  For example, ``simp_all [3]''
   738 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   739 simplifies all new goals that emerge from applying rule foo to the
   740 originally first one.
   741 
   742 * Isar: schematic goals are no longer restricted to higher-order
   743 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   744 expected.
   745 
   746 * Isar: the conclusion of a long theorem statement is now either
   747 'shows' (a simultaneous conjunction, as before), or 'obtains'
   748 (essentially a disjunction of cases with local parameters and
   749 assumptions).  The latter allows to express general elimination rules
   750 adequately; in this notation common elimination rules look like this:
   751 
   752   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   753     assumes "EX x. P x"
   754     obtains x where "P x"
   755 
   756   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   757     assumes "A & B"
   758     obtains A and B
   759 
   760   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   761     assumes "A | B"
   762     obtains
   763       A
   764     | B
   765 
   766 The subsequent classical rules even refer to the formal "thesis"
   767 explicitly:
   768 
   769   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   770     obtains "~ thesis"
   771 
   772   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   773     obtains "thesis ==> something"
   774 
   775 The actual proof of an 'obtains' statement is analogous to that of the
   776 Isar proof element 'obtain', only that there may be several cases.
   777 Optional case names may be specified in parentheses; these will be
   778 available both in the present proof and as annotations in the
   779 resulting rule, for later use with the 'cases' method (cf. attribute
   780 case_names).
   781 
   782 * Isar: the assumptions of a long theorem statement are available as
   783 "assms" fact in the proof context.  This is more appropriate than the
   784 (historical) "prems", which refers to all assumptions of the current
   785 context, including those from the target locale, proof body etc.
   786 
   787 * Isar: 'print_statement' prints theorems from the current theory or
   788 proof context in long statement form, according to the syntax of a
   789 top-level lemma.
   790 
   791 * Isar: 'obtain' takes an optional case name for the local context
   792 introduction rule (default "that").
   793 
   794 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   795 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   796 to occur.
   797 
   798 * Pure: syntax "CONST name" produces a fully internalized constant
   799 according to the current context.  This is particularly useful for
   800 syntax translations that should refer to internal constant
   801 representations independently of name spaces.
   802 
   803 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   804 instead of "FOO ". This allows multiple binder declarations to coexist
   805 in the same context.  INCOMPATIBILITY.
   806 
   807 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   808 primitive that also works in a locale context (both for constants and
   809 fixed variables). Type declaration and internal syntactic representation
   810 of given constants retrieved from the context. Likewise, the
   811 'no_notation' command allows to remove given syntax annotations from the
   812 current context.
   813 
   814 * Isar/locales: new derived specification elements 'axiomatization',
   815 'definition', 'abbreviation', which support type-inference, admit
   816 object-level specifications (equality, equivalence).  See also the
   817 isar-ref manual.  Examples:
   818 
   819   axiomatization
   820     eq  (infix "===" 50) where
   821     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   822 
   823   definition "f x y = x + y + 1"
   824   definition g where "g x = f x x"
   825 
   826   abbreviation
   827     neq  (infix "=!=" 50) where
   828     "x =!= y == ~ (x === y)"
   829 
   830 These specifications may be also used in a locale context.  Then the
   831 constants being introduced depend on certain fixed parameters, and the
   832 constant name is qualified by the locale base name.  An internal
   833 abbreviation takes care for convenient input and output, making the
   834 parameters implicit and using the original short name.  See also
   835 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   836 entities from a monomorphic theory.
   837 
   838 Presently, abbreviations are only available 'in' a target locale, but
   839 not inherited by general import expressions.  Also note that
   840 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   841 'translations' in common applications.  The "no_abbrevs" print mode
   842 prevents folding of abbreviations in term output.
   843 
   844 Concrete syntax is attached to specified constants in internal form,
   845 independently of name spaces.  The parse tree representation is
   846 slightly different -- use 'notation' instead of raw 'syntax', and
   847 'translations' with explicit "CONST" markup to accommodate this.
   848 
   849 * Pure/Isar: unified syntax for new-style specification mechanisms
   850 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   851 full type inference and dummy patterns ("_").  For example:
   852 
   853   definition "K x _ = x"
   854 
   855   inductive conj for A B
   856   where "A ==> B ==> conj A B"
   857 
   858 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   859 the current context.  Print mode "no_abbrevs" prevents inversion of
   860 abbreviations on output.
   861 
   862 * Isar/locales: improved parameter handling: use of locales "var" and
   863 "struct" no longer necessary; - parameter renamings are no longer
   864 required to be injective.  For example, this allows to define
   865 endomorphisms as locale endom = homom mult mult h.
   866 
   867 * Isar/locales: changed the way locales with predicates are defined.
   868 Instead of accumulating the specification, the imported expression is
   869 now an interpretation.  INCOMPATIBILITY: different normal form of
   870 locale expressions.  In particular, in interpretations of locales with
   871 predicates, goals repesenting already interpreted fragments are not
   872 removed automatically.  Use methods `intro_locales' and
   873 `unfold_locales'; see below.
   874 
   875 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   876 provide backward reasoning on locales predicates.  The methods are
   877 aware of interpretations and discharge corresponding goals.
   878 `intro_locales' is less aggressive then `unfold_locales' and does not
   879 unfold predicates to assumptions.
   880 
   881 * Isar/locales: the order in which locale fragments are accumulated
   882 has changed.  This enables to override declarations from fragments due
   883 to interpretations -- for example, unwanted simp rules.
   884 
   885 * Isar/locales: interpretation in theories and proof contexts has been
   886 extended.  One may now specify (and prove) equations, which are
   887 unfolded in interpreted theorems.  This is useful for replacing
   888 defined concepts (constants depending on locale parameters) by
   889 concepts already existing in the target context.  Example:
   890 
   891   interpretation partial_order ["op <= :: [int, int] => bool"]
   892     where "partial_order.less (op <=) (x::int) y = (x < y)"
   893 
   894 Typically, the constant `partial_order.less' is created by a
   895 definition specification element in the context of locale
   896 partial_order.
   897 
   898 * Method "induct": improved internal context management to support
   899 local fixes and defines on-the-fly. Thus explicit meta-level
   900 connectives !!  and ==> are rarely required anymore in inductive goals
   901 (using object-logic connectives for this purpose has been long
   902 obsolete anyway). Common proof patterns are explained in
   903 src/HOL/Induct/Common_Patterns.thy, see also
   904 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   905 examples.
   906 
   907 * Method "induct": improved handling of simultaneous goals. Instead of
   908 introducing object-level conjunction, the statement is now split into
   909 several conclusions, while the corresponding symbolic cases are nested
   910 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   911 see src/HOL/Induct/Common_Patterns.thy, for example.
   912 
   913 * Method "induct": mutual induction rules are now specified as a list
   914 of rule sharing the same induction cases. HOL packages usually provide
   915 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   916 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   917 mutual induction rules differently, i.e. like this:
   918 
   919   (induct rule: foo_bar.inducts)
   920   (induct set: foo bar)
   921   (induct pred: foo bar)
   922   (induct type: foo bar)
   923 
   924 The ML function ProjectRule.projections turns old-style rules into the
   925 new format.
   926 
   927 * Method "coinduct": dual of induction, see
   928 src/HOL/Library/Coinductive_List.thy for various examples.
   929 
   930 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   931 considered a legacy feature.
   932 
   933 * Attribute "symmetric" produces result with standardized schematic
   934 variables (index 0).  Potential INCOMPATIBILITY.
   935 
   936 * Simplifier: by default the simplifier trace only shows top level
   937 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   938 default. Thus there is less danger of being flooded by the trace. The
   939 trace indicates where parts have been suppressed.
   940   
   941 * Provers/classical: removed obsolete classical version of elim_format
   942 attribute; classical elim/dest rules are now treated uniformly when
   943 manipulating the claset.
   944 
   945 * Provers/classical: stricter checks to ensure that supplied intro,
   946 dest and elim rules are well-formed; dest and elim rules must have at
   947 least one premise.
   948 
   949 * Provers/classical: attributes dest/elim/intro take an optional
   950 weight argument for the rule (just as the Pure versions).  Weights are
   951 ignored by automated tools, but determine the search order of single
   952 rule steps.
   953 
   954 * Syntax: input syntax now supports dummy variable binding "%_. b",
   955 where the body does not mention the bound variable.  Note that dummy
   956 patterns implicitly depend on their context of bounds, which makes
   957 "{_. _}" match any set comprehension as expected.  Potential
   958 INCOMPATIBILITY -- parse translations need to cope with syntactic
   959 constant "_idtdummy" in the binding position.
   960 
   961 * Syntax: removed obsolete syntactic constant "_K" and its associated
   962 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   963 for example "A -> B" => "Pi A (%_. B)".
   964 
   965 * Pure: 'class_deps' command visualizes the subclass relation, using
   966 the graph browser tool.
   967 
   968 * Pure: 'print_theory' now suppresses certain internal declarations by
   969 default; use '!' option for full details.
   970 
   971 
   972 *** HOL ***
   973 
   974 * Method "metis" proves goals by applying the Metis general-purpose
   975 resolution prover (see also http://gilith.com/software/metis/).
   976 Examples are in the directory MetisExamples.  WARNING: the
   977 Isabelle/HOL-Metis integration does not yet work properly with
   978 multi-threading.
   979   
   980 * Command 'sledgehammer' invokes external automatic theorem provers as
   981 background processes.  It generates calls to the "metis" method if
   982 successful. These can be pasted into the proof.  Users do not have to
   983 wait for the automatic provers to return.  WARNING: does not really
   984 work with multi-threading.
   985 
   986 * New "auto_quickcheck" feature tests outermost goal statements for
   987 potential counter-examples.  Controlled by ML references
   988 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   989 5000 milliseconds).  Fails silently if statements is outside of
   990 executable fragment, or any other codgenerator problem occurs.
   991 
   992 * New constant "undefined" with axiom "undefined x = undefined".
   993 
   994 * Added class "HOL.eq", allowing for code generation with polymorphic
   995 equality.
   996 
   997 * Some renaming of class constants due to canonical name prefixing in
   998 the new 'class' package:
   999 
  1000     HOL.abs ~> HOL.abs_class.abs
  1001     HOL.divide ~> HOL.divide_class.divide
  1002     0 ~> HOL.zero_class.zero
  1003     1 ~> HOL.one_class.one
  1004     op + ~> HOL.plus_class.plus
  1005     op - ~> HOL.minus_class.minus
  1006     uminus ~> HOL.minus_class.uminus
  1007     op * ~> HOL.times_class.times
  1008     op < ~> HOL.ord_class.less
  1009     op <= > HOL.ord_class.less_eq
  1010     Nat.power ~> Power.power_class.power
  1011     Nat.size ~> Nat.size_class.size
  1012     Numeral.number_of ~> Numeral.number_class.number_of
  1013     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1014     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1015     Orderings.min ~> Orderings.ord_class.min
  1016     Orderings.max ~> Orderings.ord_class.max
  1017     Divides.op div ~> Divides.div_class.div
  1018     Divides.op mod ~> Divides.div_class.mod
  1019     Divides.op dvd ~> Divides.div_class.dvd
  1020 
  1021 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1022 
  1023 a) User-defined constants using any of the names "plus", "minus",
  1024 "times", "less" or "less_eq". The standard syntax translations for
  1025 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1026 names.
  1027 
  1028 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1029 INCOMPATIBILITY: use more specific names.
  1030 
  1031 c) Permutative equations (e.g. "a + b = b + a")
  1032 Since the change of names also changes the order of terms, permutative
  1033 rewrite rules may get applied in a different order. Experience shows
  1034 that this is rarely the case (only two adaptions in the whole Isabelle
  1035 distribution).  INCOMPATIBILITY: rewrite proofs
  1036 
  1037 d) ML code directly refering to constant names
  1038 This in general only affects hand-written proof tactics, simprocs and
  1039 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1040 Consider using @{const_name} antiquotation.
  1041 
  1042 * New class "default" with associated constant "default".
  1043 
  1044 * Function "sgn" is now overloaded and available on int, real, complex
  1045 (and other numeric types), using class "sgn".  Two possible defs of
  1046 sgn are given as equational assumptions in the classes sgn_if and
  1047 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1048 INCOMPATIBILITY.
  1049 
  1050 * Locale "partial_order" now unified with class "order" (cf. theory
  1051 Orderings), added parameter "less".  INCOMPATIBILITY.
  1052 
  1053 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1054 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1055 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1056 
  1057 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1058 changed order of proof goals in instance proofs.
  1059 
  1060 * The transitivity reasoner for partial and linear orders is set up
  1061 for classes "order" and "linorder".  Instances of the reasoner are available
  1062 in all contexts importing or interpreting the corresponding locales.
  1063 Method "order" invokes the reasoner separately; the reasoner
  1064 is also integrated with the Simplifier as a solver.  Diagnostic
  1065 command 'print_orders' shows the available instances of the reasoner
  1066 in the current context.
  1067 
  1068 * Localized monotonicity predicate in theory "Orderings"; integrated
  1069 lemmas max_of_mono and min_of_mono with this predicate.
  1070 INCOMPATIBILITY.
  1071 
  1072 * Formulation of theorem "dense" changed slightly due to integration
  1073 with new class dense_linear_order.
  1074 
  1075 * Uniform lattice theory development in HOL.
  1076 
  1077     constants "meet" and "join" now named "inf" and "sup"
  1078     constant "Meet" now named "Inf"
  1079 
  1080     classes "meet_semilorder" and "join_semilorder" now named
  1081       "lower_semilattice" and "upper_semilattice"
  1082     class "lorder" now named "lattice"
  1083     class "comp_lat" now named "complete_lattice"
  1084 
  1085     Instantiation of lattice classes allows explicit definitions
  1086     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1087 
  1088   INCOMPATIBILITY.  Theorem renames:
  1089 
  1090     meet_left_le            ~> inf_le1
  1091     meet_right_le           ~> inf_le2
  1092     join_left_le            ~> sup_ge1
  1093     join_right_le           ~> sup_ge2
  1094     meet_join_le            ~> inf_sup_ord
  1095     le_meetI                ~> le_infI
  1096     join_leI                ~> le_supI
  1097     le_meet                 ~> le_inf_iff
  1098     le_join                 ~> ge_sup_conv
  1099     meet_idempotent         ~> inf_idem
  1100     join_idempotent         ~> sup_idem
  1101     meet_comm               ~> inf_commute
  1102     join_comm               ~> sup_commute
  1103     meet_leI1               ~> le_infI1
  1104     meet_leI2               ~> le_infI2
  1105     le_joinI1               ~> le_supI1
  1106     le_joinI2               ~> le_supI2
  1107     meet_assoc              ~> inf_assoc
  1108     join_assoc              ~> sup_assoc
  1109     meet_left_comm          ~> inf_left_commute
  1110     meet_left_idempotent    ~> inf_left_idem
  1111     join_left_comm          ~> sup_left_commute
  1112     join_left_idempotent    ~> sup_left_idem
  1113     meet_aci                ~> inf_aci
  1114     join_aci                ~> sup_aci
  1115     le_def_meet             ~> le_iff_inf
  1116     le_def_join             ~> le_iff_sup
  1117     join_absorp2            ~> sup_absorb2
  1118     join_absorp1            ~> sup_absorb1
  1119     meet_absorp1            ~> inf_absorb1
  1120     meet_absorp2            ~> inf_absorb2
  1121     meet_join_absorp        ~> inf_sup_absorb
  1122     join_meet_absorp        ~> sup_inf_absorb
  1123     distrib_join_le         ~> distrib_sup_le
  1124     distrib_meet_le         ~> distrib_inf_le
  1125 
  1126     add_meet_distrib_left   ~> add_inf_distrib_left
  1127     add_join_distrib_left   ~> add_sup_distrib_left
  1128     is_join_neg_meet        ~> is_join_neg_inf
  1129     is_meet_neg_join        ~> is_meet_neg_sup
  1130     add_meet_distrib_right  ~> add_inf_distrib_right
  1131     add_join_distrib_right  ~> add_sup_distrib_right
  1132     add_meet_join_distribs  ~> add_sup_inf_distribs
  1133     join_eq_neg_meet        ~> sup_eq_neg_inf
  1134     meet_eq_neg_join        ~> inf_eq_neg_sup
  1135     add_eq_meet_join        ~> add_eq_inf_sup
  1136     meet_0_imp_0            ~> inf_0_imp_0
  1137     join_0_imp_0            ~> sup_0_imp_0
  1138     meet_0_eq_0             ~> inf_0_eq_0
  1139     join_0_eq_0             ~> sup_0_eq_0
  1140     neg_meet_eq_join        ~> neg_inf_eq_sup
  1141     neg_join_eq_meet        ~> neg_sup_eq_inf
  1142     join_eq_if              ~> sup_eq_if
  1143 
  1144     mono_meet               ~> mono_inf
  1145     mono_join               ~> mono_sup
  1146     meet_bool_eq            ~> inf_bool_eq
  1147     join_bool_eq            ~> sup_bool_eq
  1148     meet_fun_eq             ~> inf_fun_eq
  1149     join_fun_eq             ~> sup_fun_eq
  1150     meet_set_eq             ~> inf_set_eq
  1151     join_set_eq             ~> sup_set_eq
  1152     meet1_iff               ~> inf1_iff
  1153     meet2_iff               ~> inf2_iff
  1154     meet1I                  ~> inf1I
  1155     meet2I                  ~> inf2I
  1156     meet1D1                 ~> inf1D1
  1157     meet2D1                 ~> inf2D1
  1158     meet1D2                 ~> inf1D2
  1159     meet2D2                 ~> inf2D2
  1160     meet1E                  ~> inf1E
  1161     meet2E                  ~> inf2E
  1162     join1_iff               ~> sup1_iff
  1163     join2_iff               ~> sup2_iff
  1164     join1I1                 ~> sup1I1
  1165     join2I1                 ~> sup2I1
  1166     join1I1                 ~> sup1I1
  1167     join2I2                 ~> sup1I2
  1168     join1CI                 ~> sup1CI
  1169     join2CI                 ~> sup2CI
  1170     join1E                  ~> sup1E
  1171     join2E                  ~> sup2E
  1172 
  1173     is_meet_Meet            ~> is_meet_Inf
  1174     Meet_bool_def           ~> Inf_bool_def
  1175     Meet_fun_def            ~> Inf_fun_def
  1176     Meet_greatest           ~> Inf_greatest
  1177     Meet_lower              ~> Inf_lower
  1178     Meet_set_def            ~> Inf_set_def
  1179 
  1180     Sup_def                 ~> Sup_Inf
  1181     Sup_bool_eq             ~> Sup_bool_def
  1182     Sup_fun_eq              ~> Sup_fun_def
  1183     Sup_set_eq              ~> Sup_set_def
  1184 
  1185     listsp_meetI            ~> listsp_infI
  1186     listsp_meet_eq          ~> listsp_inf_eq
  1187 
  1188     meet_min                ~> inf_min
  1189     join_max                ~> sup_max
  1190 
  1191 * Added syntactic class "size"; overloaded constant "size" now has
  1192 type "'a::size ==> bool"
  1193 
  1194 * Internal reorganisation of `size' of datatypes: size theorems
  1195 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1196 simplification rules by default!); theorems "prod.size" now named
  1197 "*.size".
  1198 
  1199 * Class "div" now inherits from class "times" rather than "type".
  1200 INCOMPATIBILITY.
  1201 
  1202 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1203 Linorder etc.  have disappeared; operations defined in terms of
  1204 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1205 
  1206 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1207 
  1208 * HOL-Word: New extensive library and type for generic, fixed size
  1209 machine words, with arithemtic, bit-wise, shifting and rotating
  1210 operations, reflection into int, nat, and bool lists, automation for
  1211 linear arithmetic (by automatic reflection into nat or int), including
  1212 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1213 arithmetic type classes, supporting automatic simplification of
  1214 numerals on all operations.
  1215 
  1216 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1217 
  1218 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1219 
  1220 * Code generator library theories:
  1221   - Code_Integer represents HOL integers by big integer literals in target
  1222     languages.
  1223   - Code_Char represents HOL characters by character literals in target
  1224     languages.
  1225   - Code_Char_chr like Code_Char, but also offers treatment of character
  1226     codes; includes Code_Integer.
  1227   - Executable_Set allows to generate code for finite sets using lists.
  1228   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1229     denominator).
  1230   - Executable_Real implements a subset of real numbers, namly those
  1231     representable by rational numbers.
  1232   - Efficient_Nat implements natural numbers by integers, which in general will
  1233     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1234     includes Code_Integer.
  1235   - Code_Index provides an additional datatype index which is mapped to
  1236     target-language built-in integers.
  1237   - Code_Message provides an additional datatype message_string which is isomorphic to
  1238     strings; messages are mapped to target-language strings.
  1239 
  1240 * New package for inductive predicates
  1241 
  1242   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1243 
  1244     inductive
  1245       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1246       for z_1 :: U_1 and ... and z_n :: U_m
  1247     where
  1248       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1249     | ...
  1250 
  1251   with full support for type-inference, rather than
  1252 
  1253     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1254 
  1255     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1256     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1257 
  1258     inductive "s z_1 ... z_m"
  1259     intros
  1260       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1261       ...
  1262 
  1263   For backward compatibility, there is a wrapper allowing inductive
  1264   sets to be defined with the new package via
  1265 
  1266     inductive_set
  1267       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1268       for z_1 :: U_1 and ... and z_n :: U_m
  1269     where
  1270       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1271     | ...
  1272 
  1273   or
  1274 
  1275     inductive_set
  1276       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1277       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1278       for z_1 :: U_1 and ... and z_n :: U_m
  1279     where
  1280       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1281     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1282     | ...
  1283 
  1284   if the additional syntax "p ..." is required.
  1285 
  1286   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1287   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1288 
  1289   INCOMPATIBILITIES:
  1290 
  1291   - Since declaration and definition of inductive sets or predicates
  1292     is no longer separated, abbreviations involving the newly
  1293     introduced sets or predicates must be specified together with the
  1294     introduction rules after the 'where' keyword (see above), rather
  1295     than before the actual inductive definition.
  1296 
  1297   - The variables in induction and elimination rules are now
  1298     quantified in the order of their occurrence in the introduction
  1299     rules, rather than in alphabetical order. Since this may break
  1300     some proofs, these proofs either have to be repaired, e.g. by
  1301     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1302     statements of the form
  1303 
  1304       case (rule_i a_i_1 ... a_i_{k_i})
  1305 
  1306     or the old order of quantification has to be restored by explicitly adding
  1307     meta-level quantifiers in the introduction rules, i.e.
  1308 
  1309       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1310 
  1311   - The format of the elimination rules is now
  1312 
  1313       p z_1 ... z_m x_1 ... x_n ==>
  1314         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1315         ==> ... ==> P
  1316 
  1317     for predicates and
  1318 
  1319       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1320         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1321         ==> ... ==> P
  1322 
  1323     for sets rather than
  1324 
  1325       x : s z_1 ... z_m ==>
  1326         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1327         ==> ... ==> P
  1328 
  1329     This may require terms in goals to be expanded to n-tuples
  1330     (e.g. using case_tac or simplification with the split_paired_all
  1331     rule) before the above elimination rule is applicable.
  1332 
  1333   - The elimination or case analysis rules for (mutually) inductive
  1334     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1335     list of rules "p_1_..._p_k.elims" is no longer available.
  1336 
  1337 * New package "function"/"fun" for general recursive functions,
  1338 supporting mutual and nested recursion, definitions in local contexts,
  1339 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1340 for small examples, and the separate tutorial on the function
  1341 package. The old recdef "package" is still available as before, but
  1342 users are encouraged to use the new package.
  1343 
  1344 * Method "lexicographic_order" automatically synthesizes termination
  1345 relations as lexicographic combinations of size measures. 
  1346 
  1347 * Case-expressions allow arbitrary constructor-patterns (including
  1348 "_") and take their order into account, like in functional
  1349 programming.  Internally, this is translated into nested
  1350 case-expressions; missing cases are added and mapped to the predefined
  1351 constant "undefined". In complicated cases printing may no longer show
  1352 the original input but the internal form. Lambda-abstractions allow
  1353 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1354 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1355 variable.
  1356 
  1357 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1358 is an abbreviation for "of_nat :: nat => int". The simplification
  1359 rules for "of_nat" have been changed to work like "int" did
  1360 previously.  Potential INCOMPATIBILITY:
  1361   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1362   - of_nat_diff and of_nat_mult are no longer default simp rules
  1363 
  1364 * Method "algebra" solves polynomial equations over (semi)rings using
  1365 Groebner bases. The (semi)ring structure is defined by locales and the
  1366 tool setup depends on that generic context. Installing the method for
  1367 a specific type involves instantiating the locale and possibly adding
  1368 declarations for computation on the coefficients.  The method is
  1369 already instantiated for natural numbers and for the axiomatic class
  1370 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1371 CALCULEMUS 2007 for the general principles underlying this
  1372 architecture of context-aware proof-tools.
  1373 
  1374 * Method "ferrack" implements quantifier elimination over
  1375 special-purpose dense linear orders using locales (analogous to
  1376 "algebra"). The method is already installed for class
  1377 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1378 rat, etc.
  1379 
  1380 * Former constant "List.op @" now named "List.append".  Use ML
  1381 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1382 circumvent possible incompatibilities when working on ML level.
  1383 
  1384 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1385 
  1386 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1387 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1388 
  1389 * New syntax for Haskell-like list comprehension (input only), eg.
  1390 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1391 
  1392 * The special syntax for function "filter" has changed from [x :
  1393 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1394 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1395 
  1396 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1397 defined on nat only, as an abbreviation for [a..<Suc b]
  1398 INCOMPATIBILITY.
  1399 
  1400 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1401 
  1402 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1403 
  1404 * New lemma collection field_simps (an extension of ring_simps) for
  1405 manipulating (in)equations involving division. Multiplies with all
  1406 denominators that can be proved to be non-zero (in equations) or
  1407 positive/negative (in inequations).
  1408 
  1409 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1410 have been improved and renamed to ring_simps, group_simps and
  1411 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1412 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1413 
  1414 * Theory Library/Commutative_Ring: switched from recdef to function
  1415 package; constants add, mul, pow now curried.  Infix syntax for
  1416 algebraic operations.
  1417 
  1418 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1419 INCOMPATIBILITY.
  1420 
  1421 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1422 INCOMPATIBILITY.
  1423 
  1424 * HOL/records: generalised field-update to take a function on the
  1425 field rather than the new value: r(|A := x|) is translated to A_update
  1426 (K x) r The K-combinator that is internally used is called K_record.
  1427 INCOMPATIBILITY: Usage of the plain update functions has to be
  1428 adapted.
  1429  
  1430 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1431 * x = 0, which are required for a semiring.  Richer structures do not
  1432 inherit from semiring_0 anymore, because this property is a theorem
  1433 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1434 there is more to prove, but this is mostly trivial.
  1435 
  1436 * Class "recpower" is generalized to arbitrary monoids, not just
  1437 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1438 commutativity or semiring properties additionally.
  1439 
  1440 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1441 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1442 better use 'abbreviation'.
  1443 
  1444 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1445 
  1446 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1447 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1448 significant changes for setting up numeral syntax for types:
  1449   - New constants Numeral.pred and Numeral.succ instead
  1450       of former Numeral.bin_pred and Numeral.bin_succ.
  1451   - Use integer operations instead of bin_add, bin_mult and so on.
  1452   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1453   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1454 
  1455 See src/HOL/Integ/IntArith.thy for an example setup.
  1456 
  1457 * Command 'normal_form' computes the normal form of a term that may
  1458 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1459 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1460 heavy-duty computations because the functions are compiled to ML
  1461 first.  Correspondingly, a method "normalization" is provided.  See
  1462 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1463 
  1464 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1465 25 like -->); output depends on the "iff" print_mode, the default is
  1466 "A = B" (with priority 50).
  1467 
  1468 * Relations less (<) and less_eq (<=) are also available on type bool.
  1469 Modified syntax to disallow nesting without explicit parentheses,
  1470 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1471 INCOMPATIBILITY.
  1472 
  1473 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1474 
  1475 * Relation composition operator "op O" now has precedence 75 and binds
  1476 stronger than union and intersection. INCOMPATIBILITY.
  1477 
  1478 * The old set interval syntax "{m..n(}" (and relatives) has been
  1479 removed.  Use "{m..<n}" (and relatives) instead.
  1480 
  1481 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1482 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1483 ``declare [[simproc del: neq]]''.
  1484 
  1485 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1486 True/False.
  1487 
  1488 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1489 
  1490 * Theorem setsum_mult renamed to setsum_right_distrib.
  1491 
  1492 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1493 ``rule'' method.
  1494 
  1495 * Reimplemented methods "sat" and "satx", with several improvements:
  1496 goals no longer need to be stated as "<prems> ==> False", equivalences
  1497 (i.e. "=" on type bool) are handled, variable names of the form
  1498 "lit_<n>" are no longer reserved, significant speedup.
  1499 
  1500 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1501 zChaff is still supported as well.
  1502 
  1503 * 'inductive' and 'datatype': provide projections of mutual rules,
  1504 bundled as foo_bar.inducts;
  1505 
  1506 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1507 Library.
  1508 
  1509 * Library: moved theory Accessible_Part to main HOL.
  1510 
  1511 * Library: added theory Coinductive_List of potentially infinite lists
  1512 as greatest fixed-point.
  1513 
  1514 * Library: added theory AssocList which implements (finite) maps as
  1515 association lists.
  1516 
  1517 * Method "evaluation" solves goals (i.e. a boolean expression)
  1518 efficiently by compiling it to ML.  The goal is "proved" (via an
  1519 oracle) if it evaluates to True.
  1520 
  1521 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1522 also when invoked by the simplifier.  This results in the Simplifier
  1523 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1524 Configuration option fast_arith_split_limit=0 recovers the old
  1525 behavior.
  1526 
  1527 * Support for hex (0x20) and binary (0b1001) numerals.
  1528 
  1529 * New method: reify eqs (t), where eqs are equations for an
  1530 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1531 parameter, computes a term s::'b and a list xs::'a list and proves the
  1532 theorem I xs s = t. This is also known as reification or quoting. The
  1533 resulting theorem is applied to the subgoal to substitute t with I xs
  1534 s.  If t is omitted, the subgoal itself is reified.
  1535 
  1536 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1537 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1538 where f is supposed to be a computable function (in the sense of code
  1539 generattion). The method uses reify to compute s and xs as above then
  1540 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1541 r and finally gets the theorem t = r, which is again applied to the
  1542 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1543 
  1544 * Reflection: Automatic reification now handels binding, an example is
  1545 available in src/HOL/ex/ReflectionEx.thy
  1546 
  1547 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1548 command 'statespace' that is similar to 'record', but introduces an
  1549 abstract specification based on the locale infrastructure instead of
  1550 HOL types.  This leads to extra flexibility in composing state spaces,
  1551 in particular multiple inheritance and renaming of components.
  1552 
  1553 
  1554 *** HOL-Complex ***
  1555 
  1556 * Hyperreal: Functions root and sqrt are now defined on negative real
  1557 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1558 Nonnegativity side conditions have been removed from many lemmas, so
  1559 that more subgoals may now be solved by simplification; potential
  1560 INCOMPATIBILITY.
  1561 
  1562 * Real: new type classes formalize real normed vector spaces and
  1563 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1564 and norm :: 'a => real.
  1565 
  1566 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1567 reals into other types. The overloaded constant Reals :: 'a set is now
  1568 defined as range of_real; potential INCOMPATIBILITY.
  1569 
  1570 * Real: proper support for ML code generation, including 'quickcheck'.
  1571 Reals are implemented as arbitrary precision rationals.
  1572 
  1573 * Hyperreal: Several constants that previously worked only for the
  1574 reals have been generalized, so they now work over arbitrary vector
  1575 spaces. Type annotations may need to be added in some cases; potential
  1576 INCOMPATIBILITY.
  1577 
  1578   Infinitesimal  :: ('a::real_normed_vector) star set
  1579   HFinite        :: ('a::real_normed_vector) star set
  1580   HInfinite      :: ('a::real_normed_vector) star set
  1581   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1582   monad          :: ('a::real_normed_vector) star => 'a star set
  1583   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1584   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1585   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1586   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1587   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1588   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1589   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1590   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1591   sgn            :: 'a::real_normed_vector => 'a
  1592   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1593 
  1594 * Complex: Some complex-specific constants are now abbreviations for
  1595 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1596 hnorm.  Other constants have been entirely removed in favor of the
  1597 polymorphic versions (INCOMPATIBILITY):
  1598 
  1599   approx        <-- capprox
  1600   HFinite       <-- CFinite
  1601   HInfinite     <-- CInfinite
  1602   Infinitesimal <-- CInfinitesimal
  1603   monad         <-- cmonad
  1604   galaxy        <-- cgalaxy
  1605   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1606   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1607   (ns)deriv     <-- (ns)cderiv
  1608 
  1609 
  1610 *** HOL-Algebra ***
  1611 
  1612 * Formalisation of ideals and the quotient construction over rings.
  1613 
  1614 * Order and lattice theory no longer based on records.
  1615 INCOMPATIBILITY.
  1616 
  1617 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1618 greatest_closed.  INCOMPATIBILITY.
  1619 
  1620 * Method algebra is now set up via an attribute.  For examples see
  1621 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1622 of algebraic structures.
  1623 
  1624 * Renamed theory CRing to Ring.
  1625 
  1626 
  1627 *** HOL-Nominal ***
  1628 
  1629 * Substantial, yet incomplete support for nominal datatypes (binding
  1630 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1631 src/HOL/Nominal/Examples.  Prospective users should consult
  1632 http://isabelle.in.tum.de/nominal/
  1633 
  1634 
  1635 *** ML ***
  1636 
  1637 * ML basics: just one true type int, which coincides with IntInf.int
  1638 (even on SML/NJ).
  1639 
  1640 * ML within Isar: antiquotations allow to embed statically-checked
  1641 formal entities in the source, referring to the context available at
  1642 compile-time.  For example:
  1643 
  1644 ML {* @{sort "{zero,one}"} *}
  1645 ML {* @{typ "'a => 'b"} *}
  1646 ML {* @{term "%x. x"} *}
  1647 ML {* @{prop "x == y"} *}
  1648 ML {* @{ctyp "'a => 'b"} *}
  1649 ML {* @{cterm "%x. x"} *}
  1650 ML {* @{cprop "x == y"} *}
  1651 ML {* @{thm asm_rl} *}
  1652 ML {* @{thms asm_rl} *}
  1653 ML {* @{type_name c} *}
  1654 ML {* @{type_syntax c} *}
  1655 ML {* @{const_name c} *}
  1656 ML {* @{const_syntax c} *}
  1657 ML {* @{context} *}
  1658 ML {* @{theory} *}
  1659 ML {* @{theory Pure} *}
  1660 ML {* @{theory_ref} *}
  1661 ML {* @{theory_ref Pure} *}
  1662 ML {* @{simpset} *}
  1663 ML {* @{claset} *}
  1664 ML {* @{clasimpset} *}
  1665 
  1666 The same works for sources being ``used'' within an Isar context.
  1667 
  1668 * ML in Isar: improved error reporting; extra verbosity with
  1669 ML_Context.trace enabled.
  1670 
  1671 * Pure/General/table.ML: the join operations now works via exceptions
  1672 DUP/SAME instead of type option. This is simpler in simple cases, and
  1673 admits slightly more efficient complex applications.
  1674 
  1675 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1676 use Context.generic instead of just theory.
  1677 
  1678 * Pure: datatype Context.generic joins theory/Proof.context and
  1679 provides some facilities for code that works in either kind of
  1680 context, notably GenericDataFun for uniform theory and proof data.
  1681 
  1682 * Pure: simplified internal attribute type, which is now always
  1683 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1684 local (Proof.context) attributes have been discontinued, while
  1685 minimizing code duplication. Thm.rule_attribute and
  1686 Thm.declaration_attribute build canonical attributes; see also structure
  1687 Context for further operations on Context.generic, notably
  1688 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1689 declarations and definitions.
  1690 
  1691 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1692 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1693 init only required for impure data. INCOMPATIBILITY: empty really need
  1694 to be empty (no dependencies on theory content!)
  1695 
  1696 * Pure/kernel: consts certification ignores sort constraints given in
  1697 signature declarations. (This information is not relevant to the
  1698 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1699 potential INCOMPATIBILITY.
  1700 
  1701 * Pure: axiomatic type classes are now purely definitional, with
  1702 explicit proofs of class axioms and super class relations performed
  1703 internally. See Pure/axclass.ML for the main internal interfaces --
  1704 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1705 AxClass.axiomatize_class/classrel/arity supersede
  1706 Sign.add_classes/classrel/arities.
  1707 
  1708 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1709 global/local versions on theory vs. Proof.context have been
  1710 discontinued; Attrib.syntax and Method.syntax have been adapted
  1711 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1712 attributes, methods, etc.
  1713 
  1714 * Pure: several functions of signature "... -> theory -> theory * ..."
  1715 have been reoriented to "... -> theory -> ... * theory" in order to
  1716 allow natural usage in combination with the ||>, ||>>, |-> and
  1717 fold_map combinators.
  1718 
  1719 * Pure: official theorem names (closed derivations) and additional
  1720 comments (tags) are now strictly separate.  Name hints -- which are
  1721 maintained as tags -- may be attached any time without affecting the
  1722 derivation.
  1723 
  1724 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1725 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1726 achieve the old behaviour.
  1727 
  1728 * Pure: the "Goal" constant is now called "prop", supporting a
  1729 slightly more general idea of ``protecting'' meta-level rule
  1730 statements.
  1731 
  1732 * Pure: Logic.(un)varify only works in a global context, which is now
  1733 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1734 Logic.legacy_(un)varify as temporary workaround.
  1735 
  1736 * Pure: structure Name provides scalable operations for generating
  1737 internal variable names, notably Name.variants etc.  This replaces
  1738 some popular functions from term.ML:
  1739 
  1740   Term.variant		->  Name.variant
  1741   Term.variantlist	->  Name.variant_list
  1742   Term.invent_names	->  Name.invent_list
  1743 
  1744 Note that low-level renaming rarely occurs in new code -- operations
  1745 from structure Variable are used instead (see below).
  1746 
  1747 * Pure: structure Variable provides fundamental operations for proper
  1748 treatment of fixed/schematic variables in a context.  For example,
  1749 Variable.import introduces fixes for schematics of given facts and
  1750 Variable.export reverses the effect (up to renaming) -- this replaces
  1751 various freeze_thaw operations.
  1752 
  1753 * Pure: structure Goal provides simple interfaces for
  1754 init/conclude/finish and tactical prove operations (replacing former
  1755 Tactic.prove).  Goal.prove is the canonical way to prove results
  1756 within a given context; Goal.prove_global is a degraded version for
  1757 theory level goals, including a global Drule.standard.  Note that
  1758 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1759 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1760 in a locale context).
  1761 
  1762 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1763 and type checking (Syntax.check_term etc.), with common combinations
  1764 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1765 which are considered legacy and await removal.
  1766 
  1767 * Pure/Syntax: generic interfaces for type unchecking
  1768 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1769 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1770 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1771 available for convenience, but refer to the very same operations using
  1772 a mere theory instead of a full context.
  1773 
  1774 * Isar: simplified treatment of user-level errors, using exception
  1775 ERROR of string uniformly.  Function error now merely raises ERROR,
  1776 without any side effect on output channels.  The Isar toplevel takes
  1777 care of proper display of ERROR exceptions.  ML code may use plain
  1778 handle/can/try; cat_error may be used to concatenate errors like this:
  1779 
  1780   ... handle ERROR msg => cat_error msg "..."
  1781 
  1782 Toplevel ML code (run directly or through the Isar toplevel) may be
  1783 embedded into the Isar toplevel with exception display/debug like
  1784 this:
  1785 
  1786   Isar.toplevel (fn () => ...)
  1787 
  1788 INCOMPATIBILITY, removed special transform_error facilities, removed
  1789 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1790 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1791 -- use plain ERROR instead.
  1792 
  1793 * Isar: theory setup now has type (theory -> theory), instead of a
  1794 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1795 
  1796 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1797 ProofContext.debug/verbose flags.
  1798 
  1799 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1800 theory before entering a proof state.  Transactions now always see a
  1801 quasi-functional intermediate checkpoint, both in interactive and
  1802 batch mode.
  1803 
  1804 * Isar: simplified interfaces for outer syntax.  Renamed
  1805 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1806 OuterSyntax.add_parsers -- this functionality is now included in
  1807 OuterSyntax.command etc.  INCOMPATIBILITY.
  1808 
  1809 * Simplifier: the simpset of a running simplification process now
  1810 contains a proof context (cf. Simplifier.the_context), which is the
  1811 very context that the initial simpset has been retrieved from (by
  1812 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1813 (solver, looper etc.) may depend on arbitrary proof data.
  1814 
  1815 * Simplifier.inherit_context inherits the proof context (plus the
  1816 local bounds) of the current simplification process; any simproc
  1817 etc. that calls the Simplifier recursively should do this!  Removed
  1818 former Simplifier.inherit_bounds, which is already included here --
  1819 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1820 specify an explicit context using Simplifier.context/theory_context.
  1821 
  1822 * Simplifier/Classical Reasoner: more abstract interfaces
  1823 change_simpset/claset for modifying the simpset/claset reference of a
  1824 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1825 INCOMPATIBILITY.
  1826 
  1827 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1828 "Trueprop" etc.
  1829 
  1830 
  1831 *** System ***
  1832 
  1833 * settings: the default heap location within ISABELLE_HOME_USER now
  1834 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  1835 Isabelle installations.
  1836 
  1837 * isabelle-process: option -S (secure mode) disables some critical
  1838 operations, notably runtime compilation and evaluation of ML source
  1839 code.
  1840 
  1841 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1842 
  1843 * Support for parallel execution, using native multicore support of
  1844 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1845 independent theories, according to the given theory header
  1846 specifications. The maximum number of worker threads is specified via
  1847 usedir option -M or the "max-threads" setting in Proof General. A
  1848 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1849 to 6 on a 8-core machine.  User-code needs to observe certain
  1850 guidelines for thread-safe programming, see appendix A in the Isar
  1851 Implementation manual.
  1852 
  1853 
  1854 
  1855 New in Isabelle2005 (October 2005)
  1856 ----------------------------------
  1857 
  1858 *** General ***
  1859 
  1860 * Theory headers: the new header syntax for Isar theories is
  1861 
  1862   theory <name>
  1863   imports <theory1> ... <theoryN>
  1864   uses <file1> ... <fileM>
  1865   begin
  1866 
  1867 where the 'uses' part is optional.  The previous syntax
  1868 
  1869   theory <name> = <theory1> + ... + <theoryN>:
  1870 
  1871 will disappear in the next release.  Use isatool fixheaders to convert
  1872 existing theory files.  Note that there is no change in ancient
  1873 non-Isar theories now, but these will disappear soon.
  1874 
  1875 * Theory loader: parent theories can now also be referred to via
  1876 relative and absolute paths.
  1877 
  1878 * Command 'find_theorems' searches for a list of criteria instead of a
  1879 list of constants. Known criteria are: intro, elim, dest, name:string,
  1880 simp:term, and any term. Criteria can be preceded by '-' to select
  1881 theorems that do not match. Intro, elim, dest select theorems that
  1882 match the current goal, name:s selects theorems whose fully qualified
  1883 name contain s, and simp:term selects all simplification rules whose
  1884 lhs match term.  Any other term is interpreted as pattern and selects
  1885 all theorems matching the pattern. Available in ProofGeneral under
  1886 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1887 
  1888   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1889 
  1890 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1891 matching the current goal as introduction rule and not having "HOL."
  1892 in their name (i.e. not being defined in theory HOL).
  1893 
  1894 * Command 'thms_containing' has been discontinued in favour of
  1895 'find_theorems'; INCOMPATIBILITY.
  1896 
  1897 * Communication with Proof General is now 8bit clean, which means that
  1898 Unicode text in UTF-8 encoding may be used within theory texts (both
  1899 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1900 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1901 
  1902   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1903   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1904 
  1905 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1906 Classical Reasoner.  Typical big applications run around 2 times
  1907 faster.
  1908 
  1909 
  1910 *** Document preparation ***
  1911 
  1912 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1913 of raw sources.  Only those symbols that do not require additional
  1914 LaTeX packages (depending on comments in isabellesym.sty) are
  1915 displayed properly, everything else is left verbatim.  isatool display
  1916 and isatool print are used as front ends (these are subject to the
  1917 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1918 
  1919 * Command tags control specific markup of certain regions of text,
  1920 notably folding and hiding.  Predefined tags include "theory" (for
  1921 theory begin and end), "proof" for proof commands, and "ML" for
  1922 commands involving ML code; the additional tags "visible" and
  1923 "invisible" are unused by default.  Users may give explicit tag
  1924 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1925 interpretation of tags is determined by the LaTeX job during document
  1926 preparation: see option -V of isatool usedir, or options -n and -t of
  1927 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1928 \isadroptag.
  1929 
  1930 Several document versions may be produced at the same time via isatool
  1931 usedir (the generated index.html will link all of them).  Typical
  1932 specifications include ''-V document=theory,proof,ML'' to present
  1933 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1934 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1935 these parts without any formal replacement text.  The Isabelle site
  1936 default settings produce ''document'' and ''outline'' versions as
  1937 specified above.
  1938 
  1939 * Several new antiquotations:
  1940 
  1941   @{term_type term} prints a term with its type annotated;
  1942 
  1943   @{typeof term} prints the type of a term;
  1944 
  1945   @{const const} is the same as @{term const}, but checks that the
  1946   argument is a known logical constant;
  1947 
  1948   @{term_style style term} and @{thm_style style thm} print a term or
  1949   theorem applying a "style" to it
  1950 
  1951   @{ML text}
  1952 
  1953 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1954 definitions, equations, inequations etc., 'concl' printing only the
  1955 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1956 to print the specified premise.  TermStyle.add_style provides an ML
  1957 interface for introducing further styles.  See also the "LaTeX Sugar"
  1958 document practical applications.  The ML antiquotation prints
  1959 type-checked ML expressions verbatim.
  1960 
  1961 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1962 and 'text' support optional locale specification '(in loc)', which
  1963 specifies the default context for interpreting antiquotations.  For
  1964 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1965 
  1966 * Option 'locale=NAME' of antiquotations specifies an alternative
  1967 context interpreting the subsequent argument.  For example: @{thm
  1968 [locale=lattice] inf_assoc}.
  1969 
  1970 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1971 a proof context.
  1972 
  1973 * Proper output of antiquotations for theory commands involving a
  1974 proof context (such as 'locale' or 'theorem (in loc) ...').
  1975 
  1976 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1977 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1978 
  1979 * isatool usedir: new option -C (default true) controls whether option
  1980 -D should include a copy of the original document directory; -C false
  1981 prevents unwanted effects such as copying of administrative CVS data.
  1982 
  1983 
  1984 *** Pure ***
  1985 
  1986 * Considerably improved version of 'constdefs' command.  Now performs
  1987 automatic type-inference of declared constants; additional support for
  1988 local structure declarations (cf. locales and HOL records), see also
  1989 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1990 sequential dependencies of definitions within a single 'constdefs'
  1991 section; moreover, the declared name needs to be an identifier.  If
  1992 all fails, consider to fall back on 'consts' and 'defs' separately.
  1993 
  1994 * Improved indexed syntax and implicit structures.  First of all,
  1995 indexed syntax provides a notational device for subscripted
  1996 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1997 expressions.  Secondly, in a local context with structure
  1998 declarations, number indexes \<^sub>n or the empty index (default
  1999 number 1) refer to a certain fixed variable implicitly; option
  2000 show_structs controls printing of implicit structures.  Typical
  2001 applications of these concepts involve record types and locales.
  2002 
  2003 * New command 'no_syntax' removes grammar declarations (and
  2004 translations) resulting from the given syntax specification, which is
  2005 interpreted in the same manner as for the 'syntax' command.
  2006 
  2007 * 'Advanced' translation functions (parse_translation etc.) may depend
  2008 on the signature of the theory context being presently used for
  2009 parsing/printing, see also isar-ref manual.
  2010 
  2011 * Improved 'oracle' command provides a type-safe interface to turn an
  2012 ML expression of type theory -> T -> term into a primitive rule of
  2013 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2014 is already included here); see also FOL/ex/IffExample.thy;
  2015 INCOMPATIBILITY.
  2016 
  2017 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2018 before); "cI" is no longer bound, use "c.intro" instead.
  2019 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2020 axclasses vs. locales.
  2021 
  2022 * Improved internal renaming of symbolic identifiers -- attach primes
  2023 instead of base 26 numbers.
  2024 
  2025 * New flag show_question_marks controls printing of leading question
  2026 marks in schematic variable names.
  2027 
  2028 * In schematic variable names, *any* symbol following \<^isub> or
  2029 \<^isup> is now treated as part of the base name.  For example, the
  2030 following works without printing of awkward ".0" indexes:
  2031 
  2032   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2033     by simp
  2034 
  2035 * Inner syntax includes (*(*nested*) comments*).
  2036 
  2037 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2038 annotations as "(00...)".
  2039 
  2040 * Clear separation of logical types and nonterminals, where the latter
  2041 may only occur in 'syntax' specifications or type abbreviations.
  2042 Before that distinction was only partially implemented via type class
  2043 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2044 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2045 exotic syntax specifications may require further adaption
  2046 (e.g. Cube/Cube.thy).
  2047 
  2048 * Removed obsolete type class "logic", use the top sort {} instead.
  2049 Note that non-logical types should be declared as 'nonterminals'
  2050 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2051 specifications.
  2052 
  2053 * Attributes 'induct' and 'cases': type or set names may now be
  2054 locally fixed variables as well.
  2055 
  2056 * Simplifier: can now control the depth to which conditional rewriting
  2057 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2058 Limit.
  2059 
  2060 * Simplifier: simplification procedures may now take the current
  2061 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2062 interface), which is very useful for calling the Simplifier
  2063 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2064 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2065 low-level mk_simproc no longer applies Logic.varify internally, to
  2066 allow for use in a context of fixed variables.
  2067 
  2068 * thin_tac now works even if the assumption being deleted contains !!
  2069 or ==>.  More generally, erule now works even if the major premise of
  2070 the elimination rule contains !! or ==>.
  2071 
  2072 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2073 
  2074 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2075 from Pure, which contains all common declarations already.  Both
  2076 theories are defined via plain Isabelle/Isar .thy files.
  2077 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2078 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2079 use isatool fixcpure to adapt your theory and ML sources.
  2080 
  2081 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2082 selections of theorems in named facts via index ranges.
  2083 
  2084 * 'print_theorems': in theory mode, really print the difference
  2085 wrt. the last state (works for interactive theory development only),
  2086 in proof mode print all local facts (cf. 'print_facts');
  2087 
  2088 * 'hide': option '(open)' hides only base names.
  2089 
  2090 * More efficient treatment of intermediate checkpoints in interactive
  2091 theory development.
  2092 
  2093 * Code generator is now invoked via code_module (incremental code
  2094 generation) and code_library (modular code generation, ML structures
  2095 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2096 must be quoted when used as identifiers.
  2097 
  2098 * New 'value' command for reading, evaluating and printing terms using
  2099 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2100 quoted when used as identifier.
  2101 
  2102 
  2103 *** Locales ***
  2104 
  2105 * New commands for the interpretation of locale expressions in
  2106 theories (1), locales (2) and proof contexts (3).  These generate
  2107 proof obligations from the expression specification.  After the
  2108 obligations have been discharged, theorems of the expression are added
  2109 to the theory, target locale or proof context.  The synopsis of the
  2110 commands is a follows:
  2111 
  2112   (1) interpretation expr inst
  2113   (2) interpretation target < expr
  2114   (3) interpret expr inst
  2115 
  2116 Interpretation in theories and proof contexts require a parameter
  2117 instantiation of terms from the current context.  This is applied to
  2118 specifications and theorems of the interpreted expression.
  2119 Interpretation in locales only permits parameter renaming through the
  2120 locale expression.  Interpretation is smart in that interpretations
  2121 that are active already do not occur in proof obligations, neither are
  2122 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2123 inspect active interpretations of a particular locale.  For details,
  2124 see the Isar Reference manual.  Examples can be found in
  2125 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2126 
  2127 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2128 'interpret' instead.
  2129 
  2130 * New context element 'constrains' for adding type constraints to
  2131 parameters.
  2132 
  2133 * Context expressions: renaming of parameters with syntax
  2134 redeclaration.
  2135 
  2136 * Locale declaration: 'includes' disallowed.
  2137 
  2138 * Proper static binding of attribute syntax -- i.e. types / terms /
  2139 facts mentioned as arguments are always those of the locale definition
  2140 context, independently of the context of later invocations.  Moreover,
  2141 locale operations (renaming and type / term instantiation) are applied
  2142 to attribute arguments as expected.
  2143 
  2144 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2145 actual attributes; rare situations may require Attrib.attribute to
  2146 embed those attributes into Attrib.src that lack concrete syntax.
  2147 Attribute implementations need to cooperate properly with the static
  2148 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2149 Attrib.XXX_thm etc. already do the right thing without further
  2150 intervention.  Only unusual applications -- such as "where" or "of"
  2151 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2152 on the context and the facts involved -- may have to assign parsed
  2153 values to argument tokens explicitly.
  2154 
  2155 * Changed parameter management in theorem generation for long goal
  2156 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2157 theorem statement in rare situations.
  2158 
  2159 * Locale inspection command 'print_locale' omits notes elements.  Use
  2160 'print_locale!' to have them included in the output.
  2161 
  2162 
  2163 *** Provers ***
  2164 
  2165 * Provers/hypsubst.ML: improved version of the subst method, for
  2166 single-step rewriting: it now works in bound variable contexts. New is
  2167 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2168 rewrite a different subterm than the original subst method, which is
  2169 still available as 'simplesubst'.
  2170 
  2171 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2172 and quasi orders.
  2173 
  2174 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2175 reflexive-transitive closure of relations.
  2176 
  2177 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2178 limit (previously hard-coded with a value of 20) user-definable.
  2179 
  2180 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2181 is peformed already.  Object-logics merely need to finish their
  2182 initial simpset configuration as before.  INCOMPATIBILITY.
  2183 
  2184 
  2185 *** HOL ***
  2186 
  2187 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2188 
  2189   syntax (epsilon)
  2190     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2191 
  2192 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2193 and x-symbol; use option '-m epsilon' to get it actually printed.
  2194 Moreover, the mathematically important symbolic identifier \<epsilon>
  2195 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2196 
  2197 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2198 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2199 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2200 support corresponding Isar calculations.
  2201 
  2202 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2203 instead of ":".
  2204 
  2205 * theory SetInterval: changed the syntax for open intervals:
  2206 
  2207   Old       New
  2208   {..n(}    {..<n}
  2209   {)n..}    {n<..}
  2210   {m..n(}   {m..<n}
  2211   {)m..n}   {m<..n}
  2212   {)m..n(}  {m<..<n}
  2213 
  2214 The old syntax is still supported but will disappear in the next
  2215 release.  For conversion use the following Emacs search and replace
  2216 patterns (these are not perfect but work quite well):
  2217 
  2218   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2219   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2220 
  2221 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2222 equalities in commutative rings; method 'algebra' provides a generic
  2223 interface.
  2224 
  2225 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2226 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2227 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2228 be a tuple pattern.
  2229 
  2230 Some new syntax forms are available:
  2231 
  2232   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2233   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2234   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2235   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2236 
  2237 The latter form "\<Sum>x < k. e" used to be based on a separate
  2238 function "Summation", which has been discontinued.
  2239 
  2240 * theory Finite_Set: in structured induction proofs, the insert case
  2241 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2242 (insert F x)'.
  2243 
  2244 * The 'refute' command has been extended to support a much larger
  2245 fragment of HOL, including axiomatic type classes, constdefs and
  2246 typedefs, inductive datatypes and recursion.
  2247 
  2248 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2249 Requires zChaff with proof generation to be installed.  See
  2250 HOL/ex/SAT_Examples.thy for examples.
  2251 
  2252 * Datatype induction via method 'induct' now preserves the name of the
  2253 induction variable. For example, when proving P(xs::'a list) by
  2254 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2255 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2256 in unstructured proof scripts.
  2257 
  2258 * Reworked implementation of records.  Improved scalability for
  2259 records with many fields, avoiding performance problems for type
  2260 inference. Records are no longer composed of nested field types, but
  2261 of nested extension types. Therefore the record type only grows linear
  2262 in the number of extensions and not in the number of fields.  The
  2263 top-level (users) view on records is preserved.  Potential
  2264 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2265 old record representation. The type generated for a record is called
  2266 <record_name>_ext_type.
  2267 
  2268 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2269 proofs triggered by a record definition or a simproc (if
  2270 quick_and_dirty is enabled).  Definitions of large records can take
  2271 quite long.
  2272 
  2273 New simproc record_upd_simproc for simplification of multiple record
  2274 updates enabled by default.  Moreover, trivial updates are also
  2275 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2276 occasionally, since simplification is more powerful by default.
  2277 
  2278 * typedef: proper support for polymorphic sets, which contain extra
  2279 type-variables in the term.
  2280 
  2281 * Simplifier: automatically reasons about transitivity chains
  2282 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2283 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2284 old proofs break occasionally as simplification may now solve more
  2285 goals than previously.
  2286 
  2287 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2288 present.  Works for all partial orders (class "order"), in particular
  2289 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2290 just like y <= x.
  2291 
  2292 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2293 bound variable or a constant then the let is unfolded.  Otherwise
  2294 first a is simplified to b, and then f b is simplified to g. If
  2295 possible we abstract b from g arriving at "let x = b in h x",
  2296 otherwise we unfold the let and arrive at g.  The simproc can be
  2297 enabled/disabled by the reference use_let_simproc.  Potential
  2298 INCOMPATIBILITY since simplification is more powerful by default.
  2299 
  2300 * Classical reasoning: the meson method now accepts theorems as arguments.
  2301 
  2302 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2303 jobs to provide advice on the provability of subgoals.
  2304 
  2305 * Theory OrderedGroup and Ring_and_Field: various additions and
  2306 improvements to faciliate calculations involving equalities and
  2307 inequalities.
  2308 
  2309 The following theorems have been eliminated or modified
  2310 (INCOMPATIBILITY):
  2311 
  2312   abs_eq             now named abs_of_nonneg
  2313   abs_of_ge_0        now named abs_of_nonneg
  2314   abs_minus_eq       now named abs_of_nonpos
  2315   imp_abs_id         now named abs_of_nonneg
  2316   imp_abs_neg_id     now named abs_of_nonpos
  2317   mult_pos           now named mult_pos_pos
  2318   mult_pos_le        now named mult_nonneg_nonneg
  2319   mult_pos_neg_le    now named mult_nonneg_nonpos
  2320   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2321   mult_neg           now named mult_neg_neg
  2322   mult_neg_le        now named mult_nonpos_nonpos
  2323 
  2324 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2325      
  2326      zero_le_square
  2327      not_square_less_zero 
  2328 
  2329   The following lemmas have been deleted from Real/RealPow:
  2330   
  2331      realpow_zero_zero
  2332      realpow_two
  2333      realpow_less
  2334      zero_le_power
  2335      realpow_two_le
  2336      abs_realpow_two
  2337      realpow_two_abs     
  2338 
  2339 * Theory Parity: added rules for simplifying exponents.
  2340 
  2341 * Theory List:
  2342 
  2343 The following theorems have been eliminated or modified
  2344 (INCOMPATIBILITY):
  2345 
  2346   list_all_Nil       now named list_all.simps(1)
  2347   list_all_Cons      now named list_all.simps(2)
  2348   list_all_conv      now named list_all_iff
  2349   set_mem_eq         now named mem_iff
  2350 
  2351 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2352 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2353 
  2354 
  2355 *** HOL-Complex ***
  2356 
  2357 * Theory RealDef: better support for embedding natural numbers and
  2358 integers in the reals.
  2359 
  2360 The following theorems have been eliminated or modified
  2361 (INCOMPATIBILITY):
  2362 
  2363   exp_ge_add_one_self  now requires no hypotheses
  2364   real_of_int_add      reversed direction of equality (use [symmetric])
  2365   real_of_int_minus    reversed direction of equality (use [symmetric])
  2366   real_of_int_diff     reversed direction of equality (use [symmetric])
  2367   real_of_int_mult     reversed direction of equality (use [symmetric])
  2368 
  2369 * Theory RComplete: expanded support for floor and ceiling functions.
  2370 
  2371 * Theory Ln is new, with properties of the natural logarithm
  2372 
  2373 * Hyperreal: There is a new type constructor "star" for making
  2374 nonstandard types.  The old type names are now type synonyms:
  2375 
  2376   hypreal = real star
  2377   hypnat = nat star
  2378   hcomplex = complex star
  2379 
  2380 * Hyperreal: Many groups of similarly-defined constants have been
  2381 replaced by polymorphic versions (INCOMPATIBILITY):
  2382 
  2383   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2384 
  2385   starset      <-- starsetNat, starsetC
  2386   *s*          <-- *sNat*, *sc*
  2387   starset_n    <-- starsetNat_n, starsetC_n
  2388   *sn*         <-- *sNatn*, *scn*
  2389   InternalSets <-- InternalNatSets, InternalCSets
  2390 
  2391   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2392   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2393   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2394   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2395   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2396 
  2397 * Hyperreal: Many type-specific theorems have been removed in favor of
  2398 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2399 
  2400   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2401   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2402   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2403   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2404   right_minus <-- hypreal_add_minus
  2405   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2406   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2407   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2408   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2409   mult_1_right <-- hcomplex_mult_one_right
  2410   mult_zero_left <-- hcomplex_mult_zero_left
  2411   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2412   right_distrib <-- hypnat_add_mult_distrib2
  2413   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2414   right_inverse <-- hypreal_mult_inverse
  2415   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2416   order_refl <-- {hypreal,hypnat}_le_refl
  2417   order_trans <-- {hypreal,hypnat}_le_trans
  2418   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2419   order_less_le <-- {hypreal,hypnat}_less_le
  2420   linorder_linear <-- {hypreal,hypnat}_le_linear
  2421   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2422   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2423   add_nonneg_nonneg <-- hypreal_le_add_order
  2424 
  2425 * Hyperreal: Separate theorems having to do with type-specific
  2426 versions of constants have been merged into theorems that apply to the
  2427 new polymorphic constants (INCOMPATIBILITY):
  2428 
  2429   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2430   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2431   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2432   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2433   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2434   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2435   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2436   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2437   STAR_diff <-- {STAR,STARC}_diff
  2438   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2439     STARC_hcomplex_of_complex}_image_subset
  2440   starset_n_Un <-- starset{Nat,C}_n_Un
  2441   starset_n_Int <-- starset{Nat,C}_n_Int
  2442   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2443   starset_n_diff <-- starset{Nat,C}_n_diff
  2444   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2445   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2446   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2447   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2448   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2449   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2450   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2451   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2452   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2453   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2454   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2455   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2456   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2457   starfun_diff <-- starfun{C,RC,CR}_diff
  2458   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2459   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2460   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2461   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2462   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2463   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2464   starfun_Id <-- starfunC_Id
  2465   starfun_approx <-- starfun{Nat,CR}_approx
  2466   starfun_capprox <-- starfun{C,RC}_capprox
  2467   starfun_abs <-- starfunNat_rabs
  2468   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2469   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2470   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2471   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2472   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2473   starfun_add_approx <-- starfunCR_add_approx
  2474   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2475   starfun_divide <-- starfun{C,CR,RC}_divide
  2476   starfun_n <-- starfun{Nat,C}_n
  2477   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2478   starfun_n_add <-- starfun{Nat,C}_n_add
  2479   starfun_n_add_minus <-- starfunNat_n_add_minus
  2480   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2481   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2482   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2483 
  2484   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2485   star_n_minus <-- {hypreal,hcomplex}_minus
  2486   star_n_diff <-- {hypreal,hcomplex}_diff
  2487   star_n_mult <-- {hypreal,hcomplex}_mult
  2488   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2489   star_n_le <-- {hypreal,hypnat}_le
  2490   star_n_less <-- {hypreal,hypnat}_less
  2491   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2492   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2493   star_n_abs <-- hypreal_hrabs
  2494   star_n_divide <-- hcomplex_divide
  2495 
  2496   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2497   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2498   star_of_diff <-- hypreal_of_real_diff
  2499   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2500   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2501   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2502   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2503   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2504   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2505   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2506   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2507   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2508   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2509   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2510   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2511   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2512   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2513   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2514   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2515   star_of_power <-- hypreal_of_real_power
  2516   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2517 
  2518 * Hyperreal: new method "transfer" that implements the transfer
  2519 principle of nonstandard analysis. With a subgoal that mentions
  2520 nonstandard types like "'a star", the command "apply transfer"
  2521 replaces it with an equivalent one that mentions only standard types.
  2522 To be successful, all free variables must have standard types; non-
  2523 standard variables must have explicit universal quantifiers.
  2524 
  2525 * Hyperreal: A theory of Taylor series.
  2526 
  2527 
  2528 *** HOLCF ***
  2529 
  2530 * Discontinued special version of 'constdefs' (which used to support
  2531 continuous functions) in favor of the general Pure one with full
  2532 type-inference.
  2533 
  2534 * New simplification procedure for solving continuity conditions; it
  2535 is much faster on terms with many nested lambda abstractions (cubic
  2536 instead of exponential time).
  2537 
  2538 * New syntax for domain package: selector names are now optional.
  2539 Parentheses should be omitted unless argument is lazy, for example:
  2540 
  2541   domain 'a stream = cons "'a" (lazy "'a stream")
  2542 
  2543 * New command 'fixrec' for defining recursive functions with pattern
  2544 matching; defining multiple functions with mutual recursion is also
  2545 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2546 sinr, or any data constructor defined by the domain package. The given
  2547 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2548 syntax and examples.
  2549 
  2550 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2551 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2552 but the proof obligation additionally includes an admissibility
  2553 requirement. The packages generate instances of class cpo or pcpo,
  2554 with continuity and strictness theorems for Rep and Abs.
  2555 
  2556 * HOLCF: Many theorems have been renamed according to a more standard naming
  2557 scheme (INCOMPATIBILITY):
  2558 
  2559   foo_inject:  "foo$x = foo$y ==> x = y"
  2560   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2561   foo_less:    "(foo$x << foo$y) = (x << y)"
  2562   foo_strict:  "foo$UU = UU"
  2563   foo_defined: "... ==> foo$x ~= UU"
  2564   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2565 
  2566 
  2567 *** ZF ***
  2568 
  2569 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2570 including the First Isomorphism Theorem (on quotienting by the kernel
  2571 of a homomorphism).
  2572 
  2573 * ZF/Simplifier: install second copy of type solver that actually
  2574 makes use of TC rules declared to Isar proof contexts (or locales);
  2575 the old version is still required for ML proof scripts.
  2576 
  2577 
  2578 *** Cube ***
  2579 
  2580 * Converted to Isar theory format; use locales instead of axiomatic
  2581 theories.
  2582 
  2583 
  2584 *** ML ***
  2585 
  2586 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2587 for ||>, ||>>, |>>,
  2588 
  2589 * Pure/library.ML no longer defines its own option datatype, but uses
  2590 that of the SML basis, which has constructors NONE and SOME instead of
  2591 None and Some, as well as exception Option.Option instead of OPTION.
  2592 The functions the, if_none, is_some, is_none have been adapted
  2593 accordingly, while Option.map replaces apsome.
  2594 
  2595 * Pure/library.ML: the exception LIST has been given up in favour of
  2596 the standard exceptions Empty and Subscript, as well as
  2597 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2598 superceded by the standard hd and tl functions etc.
  2599 
  2600 A number of basic list functions are no longer exported to the ML
  2601 toplevel, as they are variants of predefined functions.  The following
  2602 suggests how one can translate existing code:
  2603 
  2604     rev_append xs ys = List.revAppend (xs, ys)
  2605     nth_elem (i, xs) = List.nth (xs, i)
  2606     last_elem xs = List.last xs
  2607     flat xss = List.concat xss
  2608     seq fs = List.app fs
  2609     partition P xs = List.partition P xs
  2610     mapfilter f xs = List.mapPartial f xs
  2611 
  2612 * Pure/library.ML: several combinators for linear functional
  2613 transformations, notably reverse application and composition:
  2614 
  2615   x |> f                f #> g
  2616   (x, y) |-> f          f #-> g
  2617 
  2618 * Pure/library.ML: introduced/changed precedence of infix operators:
  2619 
  2620   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2621   infix 2 ?;
  2622   infix 3 o oo ooo oooo;
  2623   infix 4 ~~ upto downto;
  2624 
  2625 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2626 infix operators.
  2627 
  2628 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2629 fold_map support linear functional transformations and nesting.  For
  2630 example:
  2631 
  2632   fold f [x1, ..., xN] y =
  2633     y |> f x1 |> ... |> f xN
  2634 
  2635   (fold o fold) f [xs1, ..., xsN] y =
  2636     y |> fold f xs1 |> ... |> fold f xsN
  2637 
  2638   fold f [x1, ..., xN] =
  2639     f x1 #> ... #> f xN
  2640 
  2641   (fold o fold) f [xs1, ..., xsN] =
  2642     fold f xs1 #> ... #> fold f xsN
  2643 
  2644 * Pure/library.ML: the following selectors on type 'a option are
  2645 available:
  2646 
  2647   the:               'a option -> 'a  (*partial*)
  2648   these:             'a option -> 'a  where 'a = 'b list
  2649   the_default: 'a -> 'a option -> 'a
  2650   the_list:          'a option -> 'a list
  2651 
  2652 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2653 basic operations for association lists, following natural argument
  2654 order; moreover the explicit equality predicate passed here avoids
  2655 potentially expensive polymorphic runtime equality checks.
  2656 The old functions may be expressed as follows:
  2657 
  2658   assoc = uncurry (AList.lookup (op =))
  2659   assocs = these oo AList.lookup (op =)
  2660   overwrite = uncurry (AList.update (op =)) o swap
  2661 
  2662 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2663 
  2664   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2665   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2666 
  2667 replacing make_keylist and keyfilter (occassionally used)
  2668 Naive rewrites:
  2669 
  2670   make_keylist = AList.make
  2671   keyfilter = AList.find (op =)
  2672 
  2673 * eq_fst and eq_snd now take explicit equality parameter, thus
  2674   avoiding eqtypes. Naive rewrites:
  2675 
  2676     eq_fst = eq_fst (op =)
  2677     eq_snd = eq_snd (op =)
  2678 
  2679 * Removed deprecated apl and apr (rarely used).
  2680   Naive rewrites:
  2681 
  2682     apl (n, op) =>>= curry op n
  2683     apr (op, m) =>>= fn n => op (n, m)
  2684 
  2685 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2686 provides a reasonably efficient light-weight implementation of sets as
  2687 lists.
  2688 
  2689 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2690 few new operations; existing lookup and update are now curried to
  2691 follow natural argument order (for use with fold etc.);
  2692 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2693 
  2694 * Pure/General: output via the Isabelle channels of
  2695 writeln/warning/error etc. is now passed through Output.output, with a
  2696 hook for arbitrary transformations depending on the print_mode
  2697 (cf. Output.add_mode -- the first active mode that provides a output
  2698 function wins).  Already formatted output may be embedded into further
  2699 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2700 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2701 accommodate easy composition of diagnostic messages etc.  Programmers
  2702 rarely need to care about Output.output or Output.raw at all, with
  2703 some notable exceptions: Output.output is required when bypassing the
  2704 standard channels (writeln etc.), or in token translations to produce
  2705 properly formatted results; Output.raw is required when capturing
  2706 already output material that will eventually be presented to the user
  2707 a second time.  For the default print mode, both Output.output and
  2708 Output.raw have no effect.
  2709 
  2710 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2711 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2712 cumulative results are displayed at the end of a batch session.
  2713 
  2714 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2715 replaced by File.platform_path and File.shell_path (with appropriate
  2716 hooks).  This provides a clean interface for unusual systems where the
  2717 internal and external process view of file names are different.
  2718 
  2719 * Pure: more efficient orders for basic syntactic entities: added
  2720 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2721 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2722 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2723 orders now -- potential INCOMPATIBILITY for code that depends on a
  2724 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2725 Library.sort_strings on result).
  2726 
  2727 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2728 fold_types traverse types/terms from left to right, observing natural
  2729 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2730 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2731 
  2732 * Pure: name spaces have been refined, with significant changes of the
  2733 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2734 to extern(_table).  The plain name entry path is superceded by a
  2735 general 'naming' context, which also includes the 'policy' to produce
  2736 a fully qualified name and external accesses of a fully qualified
  2737 name; NameSpace.extend is superceded by context dependent
  2738 Sign.declare_name.  Several theory and proof context operations modify
  2739 the naming context.  Especially note Theory.restore_naming and
  2740 ProofContext.restore_naming to get back to a sane state; note that
  2741 Theory.add_path is no longer sufficient to recover from
  2742 Theory.absolute_path in particular.
  2743 
  2744 * Pure: new flags short_names (default false) and unique_names
  2745 (default true) for controlling output of qualified names.  If
  2746 short_names is set, names are printed unqualified.  If unique_names is
  2747 reset, the name prefix is reduced to the minimum required to achieve
  2748 the original result when interning again, even if there is an overlap
  2749 with earlier declarations.
  2750 
  2751 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2752 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2753 (useful for printing error messages).  INCOMPATIBILITY.
  2754 
  2755 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2756 Theory.theory are now identified, referring to the universal
  2757 Context.theory (see Pure/context.ML).  Actual signature and theory
  2758 content is managed as theory data.  The old code and interfaces were
  2759 spread over many files and structures; the new arrangement introduces
  2760 considerable INCOMPATIBILITY to gain more clarity:
  2761 
  2762   Context -- theory management operations (name, identity, inclusion,
  2763     parents, ancestors, merge, etc.), plus generic theory data;
  2764 
  2765   Sign -- logical signature and syntax operations (declaring consts,
  2766     types, etc.), plus certify/read for common entities;
  2767 
  2768   Theory -- logical theory operations (stating axioms, definitions,
  2769     oracles), plus a copy of logical signature operations (consts,
  2770     types, etc.); also a few basic management operations (Theory.copy,
  2771     Theory.merge, etc.)
  2772 
  2773 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2774 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2775 for convenience -- they merely return the theory.
  2776 
  2777 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2778 
  2779 * Pure: the Isar proof context type is already defined early in Pure
  2780 as Context.proof (note that ProofContext.context and Proof.context are
  2781 aliases, where the latter is the preferred name).  This enables other
  2782 Isabelle components to refer to that type even before Isar is present.
  2783 
  2784 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2785 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2786 any of these kinds.  For example, Sign.intern typeK is now
  2787 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2788 Theory.hide_types.  Also note that former
  2789 Theory.hide_classes/types/consts are now
  2790 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2791 internalize their arguments!  INCOMPATIBILITY.
  2792 
  2793 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2794 datatype thmref (with constructors Name and NameSelection) instead of
  2795 plain string -- INCOMPATIBILITY;
  2796 
  2797 * Pure: cases produced by proof methods specify options, where NONE
  2798 means to remove case bindings -- INCOMPATIBILITY in
  2799 (RAW_)METHOD_CASES.
  2800 
  2801 * Pure: the following operations retrieve axioms or theorems from a
  2802 theory node or theory hierarchy, respectively:
  2803 
  2804   Theory.axioms_of: theory -> (string * term) list
  2805   Theory.all_axioms_of: theory -> (string * term) list
  2806   PureThy.thms_of: theory -> (string * thm) list
  2807   PureThy.all_thms_of: theory -> (string * thm) list
  2808 
  2809 * Pure: print_tac now outputs the goal through the trace channel.
  2810 
  2811 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2812 Reference Toplevel.debug (default false) controls detailed printing
  2813 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2814 controls execution profiling -- set to 1 for time and 2 for space
  2815 (both increase the runtime).
  2816 
  2817 * Isar session: The initial use of ROOT.ML is now always timed,
  2818 i.e. the log will show the actual process times, in contrast to the
  2819 elapsed wall-clock time that the outer shell wrapper produces.
  2820 
  2821 * Simplifier: improved handling of bound variables (nameless
  2822 representation, avoid allocating new strings).  Simprocs that invoke
  2823 the Simplifier recursively should use Simplifier.inherit_bounds to
  2824 avoid local name clashes.  Failure to do so produces warnings
  2825 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2826 for further details.
  2827 
  2828 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2829 bindings for all theorems stored within a given theory; this may help
  2830 in porting non-Isar theories to Isar ones, while keeping ML proof
  2831 scripts for the time being.
  2832 
  2833 * ML operator HTML.with_charset specifies the charset begin used for
  2834 generated HTML files.  For example:
  2835 
  2836   HTML.with_charset "utf-8" use_thy "Hebrew";
  2837   HTML.with_charset "utf-8" use_thy "Chinese";
  2838 
  2839 
  2840 *** System ***
  2841 
  2842 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2843 isabelle, isatool etc.).
  2844 
  2845 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2846 isatool doc, isatool mkdir, display_drafts etc.).
  2847 
  2848 * isatool usedir: option -f allows specification of the ML file to be
  2849 used by Isabelle; default is ROOT.ML.
  2850 
  2851 * New isatool version outputs the version identifier of the Isabelle
  2852 distribution being used.
  2853 
  2854 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2855 (containing Boolean satisfiability problems) into Isabelle/HOL
  2856 theories.
  2857 
  2858 
  2859 
  2860 New in Isabelle2004 (April 2004)
  2861 --------------------------------
  2862 
  2863 *** General ***
  2864 
  2865 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2866   Replaces linorder.ML.
  2867 
  2868 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2869   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2870   (\<a>...\<z>), are now considered normal letters, and can therefore
  2871   be used anywhere where an ASCII letter (a...zA...Z) has until
  2872   now. COMPATIBILITY: This obviously changes the parsing of some
  2873   terms, especially where a symbol has been used as a binder, say
  2874   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2875   as an identifier.  Fix it by inserting a space around former
  2876   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2877   existing theory and ML files.
  2878 
  2879 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2880 
  2881 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2882   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2883   a normal (but invisible) letter. For multiple letter subscripts repeat
  2884   \<^isub> like this: x\<^isub>1\<^isub>2.
  2885 
  2886 * Pure: There are now sub-/superscripts that can span more than one
  2887   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2888   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2889   superscript. The new control characters are not identifier parts.
  2890 
  2891 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2892   content of "..." to the latex file instead of \isacntrl... . The "..."
  2893   may consist of any printable characters excluding the end bracket >.
  2894 
  2895 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2896   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2897   declare constants "final", which prevents their being given a definition
  2898   later.  It is useful for constants whose behaviour is fixed axiomatically
  2899   rather than definitionally, such as the meta-logic connectives.
  2900 
  2901 * Pure: 'instance' now handles general arities with general sorts
  2902   (i.e. intersections of classes),
  2903 
  2904 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2905   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2906   It can be changed to alter the colors/layout of generated pages.
  2907 
  2908 
  2909 *** Isar ***
  2910 
  2911 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2912   cut_tac, subgoal_tac and thin_tac:
  2913   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2914     locales are no longer forced to write Isar proof scripts.
  2915     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2916     emulations.
  2917   - INCOMPATIBILITY: names of variables to be instantiated may no
  2918     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2919     This is consistent with the instantiation attribute "where".
  2920 
  2921 * Attributes "where" and "of":
  2922   - Now take type variables of instantiated theorem into account when reading
  2923     the instantiation string.  This fixes a bug that caused instantiated
  2924     theorems to have too special types in some circumstances.
  2925   - "where" permits explicit instantiations of type variables.
  2926 
  2927 * Calculation commands "moreover" and "also" no longer interfere with
  2928   current facts ("this"), admitting arbitrary combinations with "then"
  2929   and derived forms.
  2930 
  2931 * Locales:
  2932   - Goal statements involving the context element "includes" no longer
  2933     generate theorems with internal delta predicates (those ending on
  2934     "_axioms") in the premise.
  2935     Resolve particular premise with <locale>.intro to obtain old form.
  2936   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2937     specification and "includes" elements in goal statement.
  2938   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2939     [intro?] and [elim?] (respectively) by default.
  2940   - Experimental command for instantiation of locales in proof contexts:
  2941         instantiate <label>[<attrs>]: <loc>
  2942     Instantiates locale <loc> and adds all its theorems to the current context
  2943     taking into account their attributes.  Label and attrs are optional
  2944     modifiers, like in theorem declarations.  If present, names of
  2945     instantiated theorems are qualified with <label>, and the attributes
  2946     <attrs> are applied after any attributes these theorems might have already.
  2947       If the locale has assumptions, a chained fact of the form
  2948     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2949     are derived.  The command does not support old-style locales declared
  2950     with "locale (open)".
  2951       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2952 
  2953 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2954   (Isar) contexts.
  2955 
  2956 
  2957 *** HOL ***
  2958 
  2959 * Proof import: new image HOL4 contains the imported library from
  2960   the HOL4 system with about 2500 theorems. It is imported by
  2961   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2962   can be used like any other Isabelle image.  See
  2963   HOL/Import/HOL/README for more information.
  2964 
  2965 * Simplifier:
  2966   - Much improved handling of linear and partial orders.
  2967     Reasoners for linear and partial orders are set up for type classes
  2968     "linorder" and "order" respectively, and are added to the default simpset
  2969     as solvers.  This means that the simplifier can build transitivity chains
  2970     to solve goals from the assumptions.
  2971   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2972     of blast or auto after simplification become unnecessary because the goal
  2973     is solved by simplification already.
  2974 
  2975 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2976     all proved in axiomatic type classes for semirings, rings and fields.
  2977 
  2978 * Numerics:
  2979   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2980     now formalized using the Ring_and_Field theory mentioned above.
  2981   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2982     than before, because now they are set up once in a generic manner.
  2983   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2984     Look for the general versions in Ring_and_Field (and Power if they concern
  2985     exponentiation).
  2986 
  2987 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2988 
  2989 * Records:
  2990   - Record types are now by default printed with their type abbreviation
  2991     instead of the list of all field types. This can be configured via
  2992     the reference "print_record_type_abbr".
  2993   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2994     (not enabled by default).
  2995   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2996     EX x. x = sel r to True (not enabled by default).
  2997   - Tactic "record_split_simp_tac" to split and simplify records added.
  2998 
  2999 * 'specification' command added, allowing for definition by
  3000   specification.  There is also an 'ax_specification' command that
  3001   introduces the new constants axiomatically.
  3002 
  3003 * arith(_tac) is now able to generate counterexamples for reals as well.
  3004 
  3005 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3006 
  3007 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3008   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3009 
  3010 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3011   matrix theory to linear programming.
  3012 
  3013 * Unions and Intersections:
  3014   The latex output syntax of UN and INT has been changed
  3015   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3016   i.e. the index formulae has become a subscript.
  3017   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3018 
  3019 * Unions and Intersections over Intervals:
  3020   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3021   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3022   like in normal math, and corresponding versions for < and for intersection.
  3023 
  3024 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3025   lexicographic dictonary ordering has been added as "lexord".
  3026 
  3027 * ML: the legacy theory structures Int and List have been removed. They had
  3028   conflicted with ML Basis Library structures having the same names.
  3029 
  3030 * 'refute' command added to search for (finite) countermodels.  Only works
  3031   for a fragment of HOL.  The installation of an external SAT solver is
  3032   highly recommended.  See "HOL/Refute.thy" for details.
  3033 
  3034 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3035   formulae under an assignment of free variables to random values.
  3036   In contrast to 'refute', it can deal with inductive datatypes,
  3037   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3038   for examples.
  3039 
  3040 
  3041 *** HOLCF ***
  3042 
  3043 * Streams now come with concatenation and are part of the HOLCF image
  3044 
  3045 
  3046 
  3047 New in Isabelle2003 (May 2003)
  3048 ------------------------------
  3049 
  3050 *** General ***
  3051 
  3052 * Provers/simplifier:
  3053 
  3054   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3055     Assumptions are now subject to complete mutual simplification,
  3056     not just from left to right. The simplifier now preserves
  3057     the order of assumptions.
  3058 
  3059     Potential INCOMPATIBILITY:
  3060 
  3061     -- simp sometimes diverges where the old version did
  3062        not, e.g. invoking simp on the goal
  3063 
  3064         [| P (f x); y = x; f x = f y |] ==> Q
  3065 
  3066        now gives rise to the infinite reduction sequence
  3067 
  3068         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3069 
  3070        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3071        kind of problem.
  3072 
  3073     -- Tactics combining classical reasoner and simplification (such as auto)
  3074        are also affected by this change, because many of them rely on
  3075        simp. They may sometimes diverge as well or yield a different numbers
  3076        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3077        in case of problems. Sometimes subsequent calls to the classical
  3078        reasoner will fail because a preceeding call to the simplifier too
  3079        eagerly simplified the goal, e.g. deleted redundant premises.
  3080 
  3081   - The simplifier trace now shows the names of the applied rewrite rules
  3082 
  3083   - You can limit the number of recursive invocations of the simplifier
  3084     during conditional rewriting (where the simplifie tries to solve the
  3085     conditions before applying the rewrite rule):
  3086     ML "simp_depth_limit := n"
  3087     where n is an integer. Thus you can force termination where previously
  3088     the simplifier would diverge.
  3089 
  3090   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3091 
  3092   - No longer aborts on failed congruence proof.  Instead, the
  3093     congruence is ignored.
  3094 
  3095 * Pure: New generic framework for extracting programs from constructive
  3096   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3097   as HOL/Extraction for some case studies.
  3098 
  3099 * Pure: The main goal of the proof state is no longer shown by default, only
  3100 the subgoals. This behaviour is controlled by a new flag.
  3101    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3102 (ML: Proof.show_main_goal).
  3103 
  3104 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3105 rules whose conclusion matches subgoal 1:
  3106       PG menu: Isabelle/Isar -> Show me -> matching rules
  3107 The rules are ordered by how closely they match the subgoal.
  3108 In particular, rules that solve a subgoal outright are displayed first
  3109 (or rather last, the way they are printed).
  3110 (ML: ProofGeneral.print_intros())
  3111 
  3112 * Pure: New flag trace_unify_fail causes unification to print
  3113 diagnostic information (PG: in trace buffer) when it fails. This is
  3114 useful for figuring out why single step proofs like rule, erule or
  3115 assumption failed.
  3116 
  3117 * Pure: Locale specifications now produce predicate definitions
  3118 according to the body of text (covering assumptions modulo local
  3119 definitions); predicate "loc_axioms" covers newly introduced text,
  3120 while "loc" is cumulative wrt. all included locale expressions; the
  3121 latter view is presented only on export into the global theory
  3122 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3123 on the old view without predicates;
  3124 
  3125 * Pure: predefined locales "var" and "struct" are useful for sharing
  3126 parameters (as in CASL, for example); just specify something like
  3127 ``var x + var y + struct M'' as import;
  3128 
  3129 * Pure: improved thms_containing: proper indexing of facts instead of
  3130 raw theorems; check validity of results wrt. current name space;
  3131 include local facts of proof configuration (also covers active
  3132 locales), cover fixed variables in index; may use "_" in term
  3133 specification; an optional limit for the number of printed facts may
  3134 be given (the default is 40);
  3135 
  3136 * Pure: disallow duplicate fact bindings within new-style theory files
  3137 (batch-mode only);
  3138 
  3139 * Provers: improved induct method: assumptions introduced by case
  3140 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3141 the goal statement); "foo" still refers to all facts collectively;
  3142 
  3143 * Provers: the function blast.overloaded has been removed: all constants
  3144 are regarded as potentially overloaded, which improves robustness in exchange
  3145 for slight decrease in efficiency;
  3146 
  3147 * Provers/linorder: New generic prover for transitivity reasoning over
  3148 linear orders.  Note: this prover is not efficient!
  3149 
  3150 * Isar: preview of problems to finish 'show' now produce an error
  3151 rather than just a warning (in interactive mode);
  3152 
  3153 
  3154 *** HOL ***
  3155 
  3156 * arith(_tac)
  3157 
  3158  - Produces a counter example if it cannot prove a goal.
  3159    Note that the counter example may be spurious if the goal is not a formula
  3160    of quantifier-free linear arithmetic.
  3161    In ProofGeneral the counter example appears in the trace buffer.
  3162 
  3163  - Knows about div k and mod k where k is a numeral of type nat or int.
  3164 
  3165  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3166    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3167    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3168 
  3169 * simp's arithmetic capabilities have been enhanced a bit: it now
  3170 takes ~= in premises into account (by performing a case split);
  3171 
  3172 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3173 are distributed over a sum of terms;
  3174 
  3175 * New tactic "trans_tac" and method "trans" instantiate
  3176 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3177 "<=", "<" and "=").
  3178 
  3179 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3180 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3181 
  3182 * 'typedef' command has new option "open" to suppress the set
  3183 definition;
  3184 
  3185 * functions Min and Max on finite sets have been introduced (theory
  3186 Finite_Set);
  3187 
  3188 * attribute [symmetric] now works for relations as well; it turns
  3189 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3190 
  3191 * induct over a !!-quantified statement (say !!x1..xn):
  3192   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3193 
  3194 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3195 %x. None. Warning: empty_def now refers to the previously hidden definition
  3196 of the empty set.
  3197 
  3198 * Algebra: formalization of classical algebra.  Intended as base for
  3199 any algebraic development in Isabelle.  Currently covers group theory
  3200 (up to Sylow's theorem) and ring theory (Universal Property of
  3201 Univariate Polynomials).  Contributions welcome;
  3202 
  3203 * GroupTheory: deleted, since its material has been moved to Algebra;
  3204 
  3205 * Complex: new directory of the complex numbers with numeric constants,
  3206 nonstandard complex numbers, and some complex analysis, standard and
  3207 nonstandard (Jacques Fleuriot);
  3208 
  3209 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3210 
  3211 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3212 Fleuriot);
  3213 
  3214 * Real/HahnBanach: updated and adapted to locales;
  3215 
  3216 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3217 Gray and Kramer);
  3218 
  3219 * UNITY: added the Meier-Sanders theory of progress sets;
  3220 
  3221 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3222 as abstract algorithms, instantiated to the JVM;
  3223 
  3224 * Bali: Java source language formalization. Type system, operational
  3225 semantics, axiomatic semantics. Supported language features:
  3226 classes, interfaces, objects,virtual methods, static methods,
  3227 static/instance fields, arrays, access modifiers, definite
  3228 assignment, exceptions.
  3229 
  3230 
  3231 *** ZF ***
  3232 
  3233 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3234 universe, etc.);
  3235 
  3236 * Main ZF: virtually all theories converted to new-style format;
  3237 
  3238 
  3239 *** ML ***
  3240 
  3241 * Pure: Tactic.prove provides sane interface for internal proofs;
  3242 omits the infamous "standard" operation, so this is more appropriate
  3243 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3244 
  3245 * Pure: improved error reporting of simprocs;
  3246 
  3247 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3248 up simprocs;
  3249 
  3250 
  3251 *** Document preparation ***
  3252 
  3253 * uses \par instead of \\ for line breaks in theory text. This may
  3254 shift some page breaks in large documents. To get the old behaviour
  3255 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3256 
  3257 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3258 other packages
  3259 
  3260 * \<euro> now needs package babel/greek instead of marvosym (which
  3261 broke \Rightarrow)
  3262 
  3263 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3264 textcomp package)
  3265 
  3266 
  3267 
  3268 New in Isabelle2002 (March 2002)
  3269 --------------------------------
  3270 
  3271 *** Document preparation ***
  3272 
  3273 * greatly simplified document preparation setup, including more
  3274 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3275 instructive isatool mkdir; users should basically be able to get
  3276 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3277 users may run a separate document processing stage manually like this:
  3278 "isatool usedir -D output HOL Test && isatool document Test/output";
  3279 
  3280 * theory dependency graph may now be incorporated into documents;
  3281 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3282 with \includegraphics of LaTeX;
  3283 
  3284 * proper spacing of consecutive markup elements, especially text
  3285 blocks after section headings;
  3286 
  3287 * support bold style (for single symbols only), input syntax is like
  3288 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3289 
  3290 * \<bullet> is now output as bold \cdot by default, which looks much
  3291 better in printed text;
  3292 
  3293 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3294 note that these symbols are currently unavailable in Proof General /
  3295 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3296 
  3297 * isatool latex no longer depends on changed TEXINPUTS, instead
  3298 isatool document copies the Isabelle style files to the target
  3299 location;
  3300 
  3301 
  3302 *** Isar ***
  3303 
  3304 * Pure/Provers: improved proof by cases and induction;
  3305   - 'case' command admits impromptu naming of parameters (such as
  3306     "case (Suc n)");
  3307   - 'induct' method divinates rule instantiation from the inductive
  3308     claim; no longer requires excessive ?P bindings for proper
  3309     instantiation of cases;
  3310   - 'induct' method properly enumerates all possibilities of set/type
  3311     rules; as a consequence facts may be also passed through *type*
  3312     rules without further ado;
  3313   - 'induct' method now derives symbolic cases from the *rulified*
  3314     rule (before it used to rulify cases stemming from the internal
  3315     atomized version); this means that the context of a non-atomic
  3316     statement becomes is included in the hypothesis, avoiding the
  3317     slightly cumbersome show "PROP ?case" form;
  3318   - 'induct' may now use elim-style induction rules without chaining
  3319     facts, using ``missing'' premises from the goal state; this allows
  3320     rules stemming from inductive sets to be applied in unstructured
  3321     scripts, while still benefitting from proper handling of non-atomic
  3322     statements; NB: major inductive premises need to be put first, all
  3323     the rest of the goal is passed through the induction;
  3324   - 'induct' proper support for mutual induction involving non-atomic
  3325     rule statements (uses the new concept of simultaneous goals, see
  3326     below);
  3327   - append all possible rule selections, but only use the first
  3328     success (no backtracking);
  3329   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3330   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3331   - added 'print_induct_rules' (covered by help item in recent Proof
  3332     General versions);
  3333   - moved induct/cases attributes to Pure, methods to Provers;
  3334   - generic method setup instantiated for FOL and HOL;
  3335 
  3336 * Pure: support multiple simultaneous goal statements, for example
  3337 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3338 meta-level mechanism, this acts as if several individual goals had
  3339 been stated separately; in particular common proof methods need to be
  3340 repeated in order to cover all claims; note that a single elimination
  3341 step is *not* sufficient to establish the two conjunctions, so this
  3342 fails:
  3343 
  3344   assume "A & B" then have A and B ..   (*".." fails*)
  3345 
  3346 better use "obtain" in situations as above; alternative refer to
  3347 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3348 
  3349 * Pure: proper integration with ``locales''; unlike the original
  3350 version by Florian Kammller, Isar locales package high-level proof
  3351 contexts rather than raw logical ones (e.g. we admit to include
  3352 attributes everywhere); operations on locales include merge and
  3353 rename; support for implicit arguments (``structures''); simultaneous
  3354 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3355 some examples;
  3356 
  3357 * Pure: the following commands have been ``localized'', supporting a
  3358 target locale specification "(in name)": 'lemma', 'theorem',
  3359 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3360 stored both within the locale and at the theory level (exported and
  3361 qualified by the locale name);
  3362 
  3363 * Pure: theory goals may now be specified in ``long'' form, with
  3364 ad-hoc contexts consisting of arbitrary locale elements. for example
  3365 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3366 definitions may be given, too); the result is a meta-level rule with
  3367 the context elements being discharged in the obvious way;
  3368 
  3369 * Pure: new proof command 'using' allows to augment currently used
  3370 facts after a goal statement ('using' is syntactically analogous to
  3371 'apply', but acts on the goal's facts only); this allows chained facts
  3372 to be separated into parts given before and after a claim, as in
  3373 ``from a and b have C using d and e <proof>'';
  3374 
  3375 * Pure: renamed "antecedent" case to "rule_context";
  3376 
  3377 * Pure: new 'judgment' command records explicit information about the
  3378 object-logic embedding (used by several tools internally); no longer
  3379 use hard-wired "Trueprop";
  3380 
  3381 * Pure: added 'corollary' command;
  3382 
  3383 * Pure: fixed 'token_translation' command;
  3384 
  3385 * Pure: removed obsolete 'exported' attribute;
  3386 
  3387 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3388 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3389 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3390 
  3391 * Pure: method 'atomize' presents local goal premises as object-level
  3392 statements (atomic meta-level propositions); setup controlled via
  3393 rewrite rules declarations of 'atomize' attribute; example
  3394 application: 'induct' method with proper rule statements in improper
  3395 proof *scripts*;
  3396 
  3397 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3398 now consider the syntactic context of assumptions, giving a better
  3399 chance to get type-inference of the arguments right (this is
  3400 especially important for locales);
  3401 
  3402 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3403 mode;
  3404 
  3405 * Pure/obtain: the formal conclusion "thesis", being marked as
  3406 ``internal'', may no longer be reference directly in the text;
  3407 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3408 situations;
  3409 
  3410 * Pure: generic 'sym' attribute which declares a rule both as pure
  3411 'elim?' and for the 'symmetric' operation;
  3412 
  3413 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3414 text; the fixed correlation with particular command syntax has been
  3415 discontinued;
  3416 
  3417 * Pure: new method 'rules' is particularly well-suited for proof
  3418 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3419 but often produces more compact proof terms with less detours;
  3420 
  3421 * Pure/Provers/classical: simplified integration with pure rule
  3422 attributes and methods; the classical "intro?/elim?/dest?"
  3423 declarations coincide with the pure ones; the "rule" method no longer
  3424 includes classically swapped intros; "intro" and "elim" methods no
  3425 longer pick rules from the context; also got rid of ML declarations
  3426 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3427 INCOMPATIBILITY;
  3428 
  3429 * Provers/classical: attribute 'swapped' produces classical inversions
  3430 of introduction rules;
  3431 
  3432 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3433 rules instead of full simplifier context; 'iff' attribute handles
  3434 conditional rules;
  3435 
  3436 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3437 
  3438 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3439 "(permissive)" option to recover old behavior;
  3440 
  3441 * HOL: 'inductive' no longer features separate (collective) attributes
  3442 for 'intros' (was found too confusing);
  3443 
  3444 * HOL: properly declared induction rules less_induct and
  3445 wf_induct_rule;
  3446 
  3447 
  3448 *** HOL ***
  3449 
  3450 * HOL: moved over to sane numeral syntax; the new policy is as
  3451 follows:
  3452 
  3453   - 0 and 1 are polymorphic constants, which are defined on any
  3454   numeric type (nat, int, real etc.);
  3455 
  3456   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3457   binary representation internally;
  3458 
  3459   - type nat has special constructor Suc, and generally prefers Suc 0
  3460   over 1::nat and Suc (Suc 0) over 2::nat;
  3461 
  3462 This change may cause significant problems of INCOMPATIBILITY; here
  3463 are some hints on converting existing sources:
  3464 
  3465   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3466   entities, so expressions involving "-" (unary or binary minus) need
  3467   to be spaced properly;
  3468 
  3469   - existing occurrences of "1" may need to be constraint "1::nat" or
  3470   even replaced by Suc 0; similar for old "2";
  3471 
  3472   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3473 
  3474   - remove all special provisions on numerals in proofs;
  3475 
  3476 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3477 representation (depends on bin_arith_simps in the default context);
  3478 
  3479 * HOL: symbolic syntax for x^2 (numeral 2);
  3480 
  3481 * HOL: the class of all HOL types is now called "type" rather than
  3482 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3483 in axclass/classes, instance/arities, and (usually rare) occurrences
  3484 in typings (of consts etc.); internally the class is called
  3485 "HOL.type", ML programs should refer to HOLogic.typeS;
  3486 
  3487 * HOL/record package improvements:
  3488   - new derived operations "fields" to build a partial record section,
  3489     "extend" to promote a fixed record to a record scheme, and
  3490     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3491     declared as simp by default;
  3492   - shared operations ("more", "fields", etc.) now need to be always
  3493     qualified) --- potential INCOMPATIBILITY;
  3494   - removed "make_scheme" operations (use "make" with "extend") --
  3495     INCOMPATIBILITY;
  3496   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3497   - provides cases/induct rules for use with corresponding Isar
  3498     methods (for concrete records, record schemes, concrete more
  3499     parts, and schematic more parts -- in that order);
  3500   - internal definitions directly based on a light-weight abstract
  3501     theory of product types over typedef rather than datatype;
  3502 
  3503 * HOL: generic code generator for generating executable ML code from
  3504 specifications; specific support for HOL constructs such as inductive
  3505 datatypes and sets, as well as recursive functions; can be invoked
  3506 via 'generate_code' theory section;
  3507 
  3508 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3509 
  3510 * HOL: consolidated and renamed several theories.  In particular:
  3511         Ord.thy has been absorbed into HOL.thy
  3512         String.thy has been absorbed into List.thy
  3513 
  3514 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3515 (beware of argument permutation!);
  3516 
  3517 * HOL: linorder_less_split superseded by linorder_cases;
  3518 
  3519 * HOL/List: "nodups" renamed to "distinct";
  3520 
  3521 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3522 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3523   - Ex_def has changed, now need to use some_eq_ex
  3524 
  3525 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3526 in this (rare) case use:
  3527 
  3528   delSWrapper "split_all_tac"
  3529   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3530 
  3531 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3532 MAY FAIL;
  3533 
  3534 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3535 Isabelle's type classes, ^ on functions and relations has too general
  3536 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3537 necessary to attach explicit type constraints;
  3538 
  3539 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3540 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3541 renamed accordingly (eg "compI" -> "rel_compI").
  3542 
  3543 * HOL: syntax translations now work properly with numerals and records
  3544 expressions;
  3545 
  3546 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3547 of "lam" -- INCOMPATIBILITY;
  3548 
  3549 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3550 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3551 renamed "Product_Type.unit";
  3552 
  3553 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3554 
  3555 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3556 the "cases" method);
  3557 
  3558 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3559 Florian Kammller);
  3560 
  3561 * HOL/IMP: updated and converted to new-style theory format; several
  3562 parts turned into readable document, with proper Isar proof texts and
  3563 some explanations (by Gerwin Klein);
  3564 
  3565 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3566 
  3567 * HOL-Hyperreal is now a logic image;
  3568 
  3569 
  3570 *** HOLCF ***
  3571 
  3572 * Isar: consts/constdefs supports mixfix syntax for continuous
  3573 operations;
  3574 
  3575 * Isar: domain package adapted to new-style theory format, e.g. see
  3576 HOLCF/ex/Dnat.thy;
  3577 
  3578 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3579 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3580 lift.induct_tac, always use UU instead of Undef;
  3581 
  3582 * HOLCF/IMP: updated and converted to new-style theory;
  3583 
  3584 
  3585 *** ZF ***
  3586 
  3587 * Isar: proper integration of logic-specific tools and packages,
  3588 including theory commands '(co)inductive', '(co)datatype',
  3589 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3590 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3591 
  3592 * theory Main no longer includes AC; for the Axiom of Choice, base
  3593 your theory on Main_ZFC;
  3594 
  3595 * the integer library now covers quotients and remainders, with many
  3596 laws relating division to addition, multiplication, etc.;
  3597 
  3598 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3599 typeless version of the formalism;
  3600 
  3601 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3602 format;
  3603 
  3604 * ZF/Induct: new directory for examples of inductive definitions,
  3605 including theory Multiset for multiset orderings; converted to
  3606 new-style theory format;
  3607 
  3608 * ZF: many new theorems about lists, ordinals, etc.;
  3609 
  3610 
  3611 *** General ***
  3612 
  3613 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3614 variable proof controls level of detail: 0 = no proofs (only oracle
  3615 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3616 also ref manual for further ML interfaces;
  3617 
  3618 * Pure/axclass: removed obsolete ML interface
  3619 goal_subclass/goal_arity;
  3620 
  3621 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3622 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3623 separate tokens, so expressions involving minus need to be spaced
  3624 properly;
  3625 
  3626 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3627 rather than "infixl" or "infixr";
  3628 
  3629 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3630 sort constraint specifications in type inference; e.g. "x::_::foo"
  3631 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3632 type variable);
  3633 
  3634 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3635 control output of nested => (types); the default behavior is
  3636 "type_brackets";
  3637 
  3638 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3639 tokens into AST constants;
  3640 
  3641 * Pure/syntax: prefer later declarations of translations and print
  3642 translation functions; potential INCOMPATIBILITY: need to reverse
  3643 multiple declarations for same syntax element constant;
  3644 
  3645 * Pure/show_hyps reset by default (in accordance to existing Isar
  3646 practice);
  3647 
  3648 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3649 addSafter;
  3650 
  3651 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3652 as well;
  3653 
  3654 * system: tested support for MacOS X; should be able to get Isabelle +
  3655 Proof General to work in a plain Terminal after installing Poly/ML
  3656 (e.g. from the Isabelle distribution area) and GNU bash alone
  3657 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3658 support requires further installations, e.g. from
  3659 http://fink.sourceforge.net/);
  3660 
  3661 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3662 
  3663 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3664 of 40 MB), cf. ML_OPTIONS;
  3665 
  3666 * system: Proof General keywords specification is now part of the
  3667 Isabelle distribution (see etc/isar-keywords.el);
  3668 
  3669 * system: support for persistent Proof General sessions (refrain from
  3670 outdating all loaded theories on startup); user may create writable
  3671 logic images like this: ``isabelle -q HOL Test'';
  3672 
  3673 * system: smart selection of Isabelle process versus Isabelle
  3674 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3675 run both "isabelle" and "Isabelle" even if file names are badly
  3676 damaged (executable inspects the case of the first letter of its own
  3677 name); added separate "isabelle-process" and "isabelle-interface";
  3678 
  3679 * system: refrain from any attempt at filtering input streams; no
  3680 longer support ``8bit'' encoding of old isabelle font, instead proper
  3681 iso-latin characters may now be used; the related isatools
  3682 "symbolinput" and "nonascii" have disappeared as well;
  3683 
  3684 * system: removed old "xterm" interface (the print modes "xterm" and
  3685 "xterm_color" are still available for direct use in a suitable
  3686 terminal);
  3687 
  3688 
  3689 
  3690 New in Isabelle99-2 (February 2001)
  3691 -----------------------------------
  3692 
  3693 *** Overview of INCOMPATIBILITIES ***
  3694 
  3695 * HOL: please note that theories in the Library and elsewhere often use the
  3696 new-style (Isar) format; to refer to their theorems in an ML script you must
  3697 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3698 
  3699 * HOL: inductive package no longer splits induction rule aggressively,
  3700 but only as far as specified by the introductions given; the old
  3701 format may be recovered via ML function complete_split_rule or attribute
  3702 'split_rule (complete)';
  3703 
  3704 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3705 gfp_Tarski to gfp_unfold;
  3706 
  3707 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3708 
  3709 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3710 relation); infix "^^" has been renamed "``"; infix "``" has been
  3711 renamed "`"; "univalent" has been renamed "single_valued";
  3712 
  3713 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3714 operation;
  3715 
  3716 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3717 
  3718 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3719 
  3720 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3721 consequence, it is no longer monotonic wrt. the local goal context
  3722 (which is now passed through the inductive cases);
  3723 
  3724 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3725 \<gg> to \<ggreater>;
  3726 
  3727 
  3728 *** Document preparation ***
  3729 
  3730 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3731 available: are "it" for near math-mode best-style output, "sl" for
  3732 slanted text style, and "tt" for plain type-writer; if no
  3733 \isabellestyle command is given, output is according to slanted
  3734 type-writer);
  3735 
  3736 * support sub/super scripts (for single symbols only), input syntax is
  3737 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3738 
  3739 * some more standard symbols; see Appendix A of the system manual for
  3740 the complete list of symbols defined in isabellesym.sty;
  3741 
  3742 * improved isabelle style files; more abstract symbol implementation
  3743 (should now use \isamath{...} and \isatext{...} in custom symbol
  3744 definitions);
  3745 
  3746 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3747 state; Note that presentation of goal states does not conform to
  3748 actual human-readable proof documents.  Please do not include goal
  3749 states into document output unless you really know what you are doing!
  3750 
  3751 * proper indentation of antiquoted output with proportional LaTeX
  3752 fonts;
  3753 
  3754 * no_document ML operator temporarily disables LaTeX document
  3755 generation;
  3756 
  3757 * isatool unsymbolize tunes sources for plain ASCII communication;
  3758 
  3759 
  3760 *** Isar ***
  3761 
  3762 * Pure: Isar now suffers initial goal statements to contain unbound
  3763 schematic variables (this does not conform to actual readable proof
  3764 documents, due to unpredictable outcome and non-compositional proof
  3765 checking); users who know what they are doing may use schematic goals
  3766 for Prolog-style synthesis of proven results;
  3767 
  3768 * Pure: assumption method (an implicit finishing) now handles actual
  3769 rules as well;
  3770 
  3771 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3772 initial goal, declare "that" only as Pure intro (only for single
  3773 steps); the "that" rule assumption may now be involved in implicit
  3774 finishing, thus ".." becomes a feasible for trivial obtains;
  3775 
  3776 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3777 instance proofs may be performed by "..";
  3778 
  3779 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3780 statements as well;
  3781 
  3782 * Pure: more robust selection of calculational rules;
  3783 
  3784 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3785 rule (as well as the assumption rule);
  3786 
  3787 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3788 lemmas, using the graph browser tool;
  3789 
  3790 * Pure: predict failure of "show" in interactive mode;
  3791 
  3792 * Pure: 'thms_containing' now takes actual terms as arguments;
  3793 
  3794 * HOL: improved method 'induct' --- now handles non-atomic goals
  3795 (potential INCOMPATIBILITY); tuned error handling;
  3796 
  3797 * HOL: cases and induct rules now provide explicit hints about the
  3798 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3799 any remaining facts are inserted into the goal verbatim;
  3800 
  3801 * HOL: local contexts (aka cases) may now contain term bindings as
  3802 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3803 the result to be shown in each case;
  3804 
  3805 * HOL: added 'recdef_tc' command;
  3806 
  3807 * isatool convert assists in eliminating legacy ML scripts;
  3808 
  3809 
  3810 *** HOL ***
  3811 
  3812 * HOL/Library: a collection of generic theories to be used together
  3813 with main HOL; the theory loader path already includes this directory
  3814 by default; the following existing theories have been moved here:
  3815 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3816 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3817 
  3818 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3819 modelling and verification task performed in Isabelle/HOL +
  3820 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3821 
  3822 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3823 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3824 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3825 'domain', this makes the theory consistent with mathematical
  3826 literature;
  3827 
  3828 * HOL basics: added overloaded operations "inverse" and "divide"
  3829 (infix "/"), syntax for generic "abs" operation, generic summation
  3830 operator \<Sum>;
  3831 
  3832 * HOL/typedef: simplified package, provide more useful rules (see also
  3833 HOL/subset.thy);
  3834 
  3835 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3836 now expressed as a proper nested rule (old-style tactic scripts may
  3837 require atomize_strip_tac to cope with non-atomic premises);
  3838 
  3839 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3840 to "split_conv" (old name still available for compatibility);
  3841 
  3842 * HOL: improved concrete syntax for strings (e.g. allows translation
  3843 rules with string literals);
  3844 
  3845 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3846  and Fleuriot's mechanization of analysis, including the transcendental
  3847  functions for the reals;
  3848 
  3849 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3850 
  3851 
  3852 *** CTT ***
  3853 
  3854 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3855 "lam" is displayed as TWO lambda-symbols
  3856 
  3857 * CTT: theory Main now available, containing everything (that is, Bool
  3858 and Arith);
  3859 
  3860 
  3861 *** General ***
  3862 
  3863 * Pure: the Simplifier has been implemented properly as a derived rule
  3864 outside of the actual kernel (at last!); the overall performance
  3865 penalty in practical applications is about 50%, while reliability of
  3866 the Isabelle inference kernel has been greatly improved;
  3867 
  3868 * print modes "brackets" and "no_brackets" control output of nested =>
  3869 (types) and ==> (props); the default behaviour is "brackets";
  3870 
  3871 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3872 as assumptions as well;
  3873 
  3874 * system: support Poly/ML 4.0;
  3875 
  3876 * system: isatool install handles KDE version 1 or 2;
  3877 
  3878 
  3879 
  3880 New in Isabelle99-1 (October 2000)
  3881 ----------------------------------
  3882 
  3883 *** Overview of INCOMPATIBILITIES ***
  3884 
  3885 * HOL: simplification of natural numbers is much changed; to partly
  3886 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3887 issue the following ML commands:
  3888 
  3889   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3890   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3891 
  3892 * HOL: simplification no longer dives into case-expressions; this is
  3893 controlled by "t.weak_case_cong" for each datatype t;
  3894 
  3895 * HOL: nat_less_induct renamed to less_induct;
  3896 
  3897 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3898 fixsome to patch .thy and .ML sources automatically;
  3899 
  3900   select_equality  -> some_equality
  3901   select_eq_Ex     -> some_eq_ex
  3902   selectI2EX       -> someI2_ex
  3903   selectI2         -> someI2
  3904   selectI          -> someI
  3905   select1_equality -> some1_equality
  3906   Eps_sym_eq       -> some_sym_eq_trivial
  3907   Eps_eq           -> some_eq_trivial
  3908 
  3909 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3910 
  3911 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3912 instead);
  3913 
  3914 * HOL: the recursion equations generated by 'recdef' are now called
  3915 f.simps instead of f.rules;
  3916 
  3917 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3918 
  3919 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3920 sometimes be needed;
  3921 
  3922 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3923 
  3924 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3925 
  3926 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3927 product is now "<*>" instead of "Times"; the lexicographic product is
  3928 now "<*lex*>" instead of "**";
  3929 
  3930 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3931 of main HOL, but was unused); better use HOL's datatype package;
  3932 
  3933 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3934 the old syntax may be recovered as follows:
  3935 
  3936   syntax (symbols)
  3937     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3938       (infixl "\\<oplus>" 100)
  3939 
  3940 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3941 
  3942 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3943 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3944 internally;
  3945 
  3946 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3947 changed from A/r to A//r;
  3948 
  3949 * ZF: new treatment of arithmetic (nat & int) may break some old
  3950 proofs;
  3951 
  3952 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3953 rulify -> rule_format, elimify -> elim_format, ...);
  3954 
  3955 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3956 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3957 should have to change intro!! to intro? only); replaced "delrule" by
  3958 "rule del";
  3959 
  3960 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3961 
  3962 * Provers: strengthened force_tac by using new first_best_tac;
  3963 
  3964 * LaTeX document preparation: several changes of isabelle.sty (see
  3965 lib/texinputs);
  3966 
  3967 
  3968 *** Document preparation ***
  3969 
  3970 * formal comments (text blocks etc.) in new-style theories may now
  3971 contain antiquotations of thm/prop/term/typ/text to be presented
  3972 according to latex print mode; concrete syntax is like this:
  3973 @{term[show_types] "f(x) = a + x"};
  3974 
  3975 * isatool mkdir provides easy setup of Isabelle session directories,
  3976 including proper document sources;
  3977 
  3978 * generated LaTeX sources are now deleted after successful run
  3979 (isatool document -c); may retain a copy somewhere else via -D option
  3980 of isatool usedir;
  3981 
  3982 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3983 style files, achieving self-contained LaTeX sources and simplifying
  3984 LaTeX debugging;
  3985 
  3986 * old-style theories now produce (crude) LaTeX output as well;
  3987 
  3988 * browser info session directories are now self-contained (may be put
  3989 on WWW server seperately); improved graphs of nested sessions; removed
  3990 graph for 'all sessions';
  3991 
  3992 * several improvements in isabelle style files; \isabellestyle{it}
  3993 produces fake math mode output; \isamarkupheader is now \section by
  3994 default; see lib/texinputs/isabelle.sty etc.;
  3995 
  3996 
  3997 *** Isar ***
  3998 
  3999 * Isar/Pure: local results and corresponding term bindings are now
  4000 subject to Hindley-Milner polymorphism (similar to ML); this
  4001 accommodates incremental type-inference very nicely;
  4002 
  4003 * Isar/Pure: new derived language element 'obtain' supports
  4004 generalized existence reasoning;
  4005 
  4006 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4007 support accumulation of results, without applying any rules yet;
  4008 useful to collect intermediate results without explicit name
  4009 references, and for use with transitivity rules with more than 2
  4010 premises;
  4011 
  4012 * Isar/Pure: scalable support for case-analysis type proofs: new
  4013 'case' language element refers to local contexts symbolically, as
  4014 produced by certain proof methods; internally, case names are attached
  4015 to theorems as "tags";
  4016 
  4017 * Isar/Pure: theory command 'hide' removes declarations from
  4018 class/type/const name spaces;
  4019 
  4020 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4021 indicate potential overloading;
  4022 
  4023 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4024 
  4025 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4026 "{a,b,c}" instead of {a,b,c};
  4027 
  4028 * Isar/Pure now provides its own version of intro/elim/dest
  4029 attributes; useful for building new logics, but beware of confusion
  4030 with the version in Provers/classical;
  4031 
  4032 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4033 case name 'antecedent';
  4034 
  4035 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4036 to the current context is now done automatically);
  4037 
  4038 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4039 for definining proof methods in ML;
  4040 
  4041 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4042 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4043 most cases, one should have to change intro!! to intro? only);
  4044 replaced "delrule" by "rule del";
  4045 
  4046 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4047 'symmetric' attribute (the latter supercedes [RS sym]);
  4048 
  4049 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4050 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4051 well (including splits);
  4052 
  4053 * Isar/Provers: Simplifier and Classical methods now support all kind
  4054 of modifiers used in the past, including 'cong', 'iff', etc.
  4055 
  4056 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4057 of Simplifier and Classical reasoner);
  4058 
  4059 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4060 now support named cases; major packages (inductive, datatype, primrec,
  4061 recdef) support case names and properly name parameters;
  4062 
  4063 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4064 monotonicity conditions are extracted to be proven at end of
  4065 calculations;
  4066 
  4067 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4068 method anyway;
  4069 
  4070 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4071 split_if split_if_asm; datatype package provides theorems foo.splits =
  4072 foo.split foo.split_asm for each datatype;
  4073 
  4074 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4075 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4076 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4077 use "(cases (simplified))" method in proper proof texts);
  4078 
  4079 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4080 
  4081 * Isar: names of theorems etc. may be natural numbers as well;
  4082 
  4083 * Isar: 'pr' command: optional arguments for goals_limit and
  4084 ProofContext.prems_limit; no longer prints theory contexts, but only
  4085 proof states;
  4086 
  4087 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4088 additional print modes to be specified; e.g. "pr(latex)" will print
  4089 proof state according to the Isabelle LaTeX style;
  4090 
  4091 * Isar: improved support for emulating tactic scripts, including proof
  4092 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4093 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4094 (for HOL datatypes);
  4095 
  4096 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4097 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4098 'proof method scripts' have to be in depth-first order;
  4099 
  4100 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4101 
  4102 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4103 should instead use individual commands for printing items
  4104 (print_commands, print_methods etc.);
  4105 
  4106 * Isar: added 'nothing' --- the empty list of theorems;
  4107 
  4108 
  4109 *** HOL ***
  4110 
  4111 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4112 corresponding virtual machine and a specification of its bytecode
  4113 verifier and a lightweight bytecode verifier, including proofs of
  4114 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4115 Cornelia Pusch (see also the homepage of project Bali at
  4116 http://isabelle.in.tum.de/Bali/);
  4117 
  4118 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4119 Clemens Ballarin;
  4120 
  4121 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4122 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4123 Rasmussen;
  4124 
  4125 * HOL/Lattice: fundamental concepts of lattice theory and order
  4126 structures, including duals, properties of bounds versus algebraic
  4127 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4128 Theorem for complete lattices etc.; may also serve as a demonstration
  4129 for abstract algebraic reasoning using axiomatic type classes, and
  4130 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4131 
  4132 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4133 von Oheimb;
  4134 
  4135 * HOL/IMPP: extension of IMP with local variables and mutually
  4136 recursive procedures, by David von Oheimb;
  4137 
  4138 * HOL/Lambda: converted into new-style theory and document;
  4139 
  4140 * HOL/ex/Multiquote: example of multiple nested quotations and
  4141 anti-quotations -- basically a generalized version of de-Bruijn
  4142 representation; very useful in avoiding lifting of operations;
  4143 
  4144 * HOL/record: added general record equality rule to simpset; fixed
  4145 select-update simplification procedure to handle extended records as
  4146 well; admit "r" as field name;
  4147 
  4148 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4149 other numeric types and also as the identity of groups, rings, etc.;
  4150 
  4151 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4152 Types nat and int belong to this axclass;
  4153 
  4154 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4155    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4156    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4157   two terms #m*u and #n*u are replaced by #(m+n)*u
  4158     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4159   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4160     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4161 
  4162 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4163 powerful prover for predicate logic but knows nothing of clasets; see
  4164 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4165 
  4166 * HOL: new version of "case_tac" subsumes both boolean case split and
  4167 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4168 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4169 
  4170 * HOL: simplification no longer dives into case-expressions: only the
  4171 selector expression is simplified, but not the remaining arms; to
  4172 enable full simplification of case-expressions for datatype t, you may
  4173 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4174 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4175 
  4176 * HOL/recdef: the recursion equations generated by 'recdef' for
  4177 function 'f' are now called f.simps instead of f.rules; if all
  4178 termination conditions are proved automatically, these simplification
  4179 rules are added to the simpset, as in primrec; rules may be named
  4180 individually as well, resulting in a separate list of theorems for
  4181 each equation;
  4182 
  4183 * HOL/While is a new theory that provides a while-combinator. It
  4184 permits the definition of tail-recursive functions without the
  4185 provision of a termination measure. The latter is necessary once the
  4186 invariant proof rule for while is applied.
  4187 
  4188 * HOL: new (overloaded) notation for the set of elements below/above
  4189 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4190 
  4191 * HOL: theorems impI, allI, ballI bound as "strip";
  4192 
  4193 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4194 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4195 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4196 
  4197 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4198 
  4199 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4200 main HOL, but was unused);
  4201 
  4202 * HOL: fewer consts declared as global (e.g. have to refer to
  4203 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4204 
  4205 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4206 in case of overlap with user translations (e.g. judgements over
  4207 tuples); (note that the underlying logical represenation is still
  4208 bogus);
  4209 
  4210 
  4211 *** ZF ***
  4212 
  4213 * ZF: simplification automatically cancels common terms in arithmetic
  4214 expressions over nat and int;
  4215 
  4216 * ZF: new treatment of nat to minimize type-checking: all operators
  4217 coerce their operands to a natural number using the function natify,
  4218 making the algebraic laws unconditional;
  4219 
  4220 * ZF: as above, for int: operators coerce their operands to an integer
  4221 using the function intify;
  4222 
  4223 * ZF: the integer library now contains many of the usual laws for the
  4224 orderings, including $<=, and monotonicity laws for $+ and $*;
  4225 
  4226 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4227 simplification;
  4228 
  4229 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4230 to the simplifier and classical reasoner simultaneously;
  4231 
  4232 
  4233 *** General ***
  4234 
  4235 * Provers: blast_tac now handles actual object-logic rules as
  4236 assumptions; note that auto_tac uses blast_tac internally as well;
  4237 
  4238 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4239 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4240 
  4241 * Provers: delrules now handles destruct rules as well (no longer need
  4242 explicit make_elim);
  4243 
  4244 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4245   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4246 use instead the strong form,
  4247   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4248 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4249 from destruct-rules;
  4250 
  4251 * Provers: Simplifier.easy_setup provides a fast path to basic
  4252 Simplifier setup for new object-logics;
  4253 
  4254 * Pure: AST translation rules no longer require constant head on LHS;
  4255 
  4256 * Pure: improved name spaces: ambiguous output is qualified; support
  4257 for hiding of names;
  4258 
  4259 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4260 XSYMBOL_HOME; no longer need to do manual configuration in most
  4261 situations;
  4262 
  4263 * system: compression of ML heaps images may now be controlled via -c
  4264 option of isabelle and isatool usedir (currently only observed by
  4265 Poly/ML);
  4266 
  4267 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4268 useful for remote X11);
  4269 
  4270 * system: provide TAGS file for Isabelle sources;
  4271 
  4272 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4273 order;
  4274 
  4275 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4276 timing flag supersedes proof_timing and Toplevel.trace;
  4277 
  4278 * ML: new combinators |>> and |>>> for incremental transformations
  4279 with secondary results (e.g. certain theory extensions):
  4280 
  4281 * ML: PureThy.add_defs gets additional argument to indicate potential
  4282 overloading (usually false);
  4283 
  4284 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4285 results;
  4286 
  4287 
  4288 
  4289 New in Isabelle99 (October 1999)
  4290 --------------------------------
  4291 
  4292 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4293 
  4294 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4295 are no longer simplified.  (This allows the simplifier to unfold recursive
  4296 functional programs.)  To restore the old behaviour, declare
  4297 
  4298     Delcongs [if_weak_cong];
  4299 
  4300 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4301 complement;
  4302 
  4303 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4304 
  4305 * HOL/datatype: mutual_induct_tac no longer exists --
  4306   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4307 
  4308 * HOL/typedef: fixed type inference for representing set; type
  4309 arguments now have to occur explicitly on the rhs as type constraints;
  4310 
  4311 * ZF: The con_defs part of an inductive definition may no longer refer
  4312 to constants declared in the same theory;
  4313 
  4314 * HOL, ZF: the function mk_cases, generated by the inductive
  4315 definition package, has lost an argument.  To simplify its result, it
  4316 uses the default simpset instead of a supplied list of theorems.
  4317 
  4318 * HOL/List: the constructors of type list are now Nil and Cons;
  4319 
  4320 * Simplifier: the type of the infix ML functions
  4321         setSSolver addSSolver setSolver addSolver
  4322 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4323 for packaging solvers. A solver is created via
  4324         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4325 where the string argument is only a comment.
  4326 
  4327 
  4328 *** Proof tools ***
  4329 
  4330 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4331 decision procedure for linear arithmetic. Currently it is used for
  4332 types `nat', `int', and `real' in HOL (see below); it can, should and
  4333 will be instantiated for other types and logics as well.
  4334 
  4335 * The simplifier now accepts rewrite rules with flexible heads, eg
  4336      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4337   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4338   matching.
  4339 
  4340 
  4341 *** General ***
  4342 
  4343 * New Isabelle/Isar subsystem provides an alternative to traditional
  4344 tactical theorem proving; together with the ProofGeneral/isar user
  4345 interface it offers an interactive environment for developing human
  4346 readable proof documents (Isar == Intelligible semi-automated
  4347 reasoning); for further information see isatool doc isar-ref,
  4348 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4349 
  4350 * improved and simplified presentation of theories: better HTML markup
  4351 (including colors), graph views in several sizes; isatool usedir now
  4352 provides a proper interface for user theories (via -P option); actual
  4353 document preparation based on (PDF)LaTeX is available as well (for
  4354 new-style theories only); see isatool doc system for more information;
  4355 
  4356 * native support for Proof General, both for classic Isabelle and
  4357 Isabelle/Isar;
  4358 
  4359 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4360 using the graph browser tool;
  4361 
  4362 * Isabelle manuals now also available as PDF;
  4363 
  4364 * theory loader rewritten from scratch (may not be fully
  4365 bug-compatible); old loadpath variable has been replaced by show_path,
  4366 add_path, del_path, reset_path functions; new operations such as
  4367 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4368 isatool doc ref);
  4369 
  4370 * improved isatool install: option -k creates KDE application icon,
  4371 option -p DIR installs standalone binaries;
  4372 
  4373 * added ML_PLATFORM setting (useful for cross-platform installations);
  4374 more robust handling of platform specific ML images for SML/NJ;
  4375 
  4376 * the settings environment is now statically scoped, i.e. it is never
  4377 created again in sub-processes invoked from isabelle, isatool, or
  4378 Isabelle;
  4379 
  4380 * path element specification '~~' refers to '$ISABELLE_HOME';
  4381 
  4382 * in locales, the "assumes" and "defines" parts may be omitted if
  4383 empty;
  4384 
  4385 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4386 long arrows);
  4387 
  4388 * new print_mode "HTML";
  4389 
  4390 * new flag show_tags controls display of tags of theorems (which are
  4391 basically just comments that may be attached by some tools);
  4392 
  4393 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4394 mode and goal output format:
  4395 
  4396 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4397 244c244
  4398 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4399 ---
  4400 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4401 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4402 181c181
  4403 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4404 ---
  4405 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4406 
  4407 * function bind_thms stores lists of theorems (cf. bind_thm);
  4408 
  4409 * new shorthand tactics ftac, eatac, datac, fatac;
  4410 
  4411 * qed (and friends) now accept "" as result name; in that case the
  4412 theorem is not stored, but proper checks and presentation of the
  4413 result still apply;
  4414 
  4415 * theorem database now also indexes constants "Trueprop", "all",
  4416 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4417 
  4418 
  4419 *** HOL ***
  4420 
  4421 ** HOL arithmetic **
  4422 
  4423 * There are now decision procedures for linear arithmetic over nat and
  4424 int:
  4425 
  4426 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4427 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4428 are treated as atomic; subformulae not involving type `nat' or `int'
  4429 are ignored; quantified subformulae are ignored unless they are
  4430 positive universal or negative existential. The tactic has to be
  4431 invoked by hand and can be a little bit slow. In particular, the
  4432 running time is exponential in the number of occurrences of `min' and
  4433 `max', and `-' on `nat'.
  4434 
  4435 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4436 (negated) (in)equalities among the premises and the conclusion into
  4437 account (i.e. no compound formulae) and does not know about `min' and
  4438 `max', and `-' on `nat'. It is fast and is used automatically by the
  4439 simplifier.
  4440 
  4441 NB: At the moment, these decision procedures do not cope with mixed
  4442 nat/int formulae where the two parts interact, such as `m < n ==>
  4443 int(m) < int(n)'.
  4444 
  4445 * HOL/Numeral provides a generic theory of numerals (encoded
  4446 efficiently as bit strings); setup for types nat/int/real is in place;
  4447 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4448 int, existing theories and proof scripts may require a few additional
  4449 type constraints;
  4450 
  4451 * integer division and remainder can now be performed on constant
  4452 arguments;
  4453 
  4454 * many properties of integer multiplication, division and remainder
  4455 are now available;
  4456 
  4457 * An interface to the Stanford Validity Checker (SVC) is available through the
  4458 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4459 are proved automatically.  SVC must be installed separately, and its results
  4460 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4461 invocation of the underlying oracle).  For SVC see
  4462   http://verify.stanford.edu/SVC
  4463 
  4464 * IsaMakefile: the HOL-Real target now builds an actual image;
  4465 
  4466 
  4467 ** HOL misc **
  4468 
  4469 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4470 (in Isabelle/Isar) -- by Gertrud Bauer;
  4471 
  4472 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4473 analysis for assembly languages with subtypes;
  4474 
  4475 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4476 -- avoids syntactic ambiguities and treats state, transition, and
  4477 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4478 changed syntax and (many) tactics;
  4479 
  4480 * HOL/inductive: Now also handles more general introduction rules such
  4481   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4482   theorems are now maintained within the theory (maintained via the
  4483   "mono" attribute);
  4484 
  4485 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4486   (using function types) such as
  4487 
  4488   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4489 
  4490 * HOL/record: record_simproc (part of the default simpset) takes care
  4491 of selectors applied to updated records; record_split_tac is no longer
  4492 part of the default claset; update_defs may now be removed from the
  4493 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4494 
  4495   claset_ref () := claset() addSWrapper record_split_wrapper;
  4496   Delsimprocs [record_simproc]
  4497 
  4498 * HOL/typedef: fixed type inference for representing set; type
  4499 arguments now have to occur explicitly on the rhs as type constraints;
  4500 
  4501 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4502 names rather than an ML expression;
  4503 
  4504 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4505 supplied later.  Program schemes can be defined, such as
  4506     "While B C s = (if B s then While B C (C s) else s)"
  4507 where the well-founded relation can be chosen after B and C have been given.
  4508 
  4509 * HOL/List: the constructors of type list are now Nil and Cons;
  4510 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4511 course, ML tools referring to List.list.op # etc. have to be adapted;
  4512 
  4513 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4514 disabled by default; run isabelle with option -m HOL to get back to
  4515 the original Gordon/HOL-style output;
  4516 
  4517 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4518 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4519 
  4520 * HOL basic syntax simplified (more orthogonal): all variants of
  4521 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4522 Eps operator is provided as well: "SOME x. P[x]";
  4523 
  4524 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4525 
  4526 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4527 thus available for user theories;
  4528 
  4529 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4530 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4531 time;
  4532 
  4533 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4534 several times and then mp;
  4535 
  4536 
  4537 *** LK ***
  4538 
  4539 * the notation <<...>> is now available as a notation for sequences of
  4540 formulas;
  4541 
  4542 * the simplifier is now installed
  4543 
  4544 * the axiom system has been generalized (thanks to Soren Heilmann)
  4545 
  4546 * the classical reasoner now has a default rule database
  4547 
  4548 
  4549 *** ZF ***
  4550 
  4551 * new primrec section allows primitive recursive functions to be given
  4552 directly (as in HOL) over datatypes and the natural numbers;
  4553 
  4554 * new tactics induct_tac and exhaust_tac for induction (or case
  4555 analysis) over datatypes and the natural numbers;
  4556 
  4557 * the datatype declaration of type T now defines the recursor T_rec;
  4558 
  4559 * simplification automatically does freeness reasoning for datatype
  4560 constructors;
  4561 
  4562 * automatic type-inference, with AddTCs command to insert new
  4563 type-checking rules;
  4564 
  4565 * datatype introduction rules are now added as Safe Introduction rules
  4566 to the claset;
  4567 
  4568 * the syntax "if P then x else y" is now available in addition to
  4569 if(P,x,y);
  4570 
  4571 
  4572 *** Internal programming interfaces ***
  4573 
  4574 * tuned simplifier trace output; new flag debug_simp;
  4575 
  4576 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4577 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4578 
  4579 * AxClass.axclass_tac lost the theory argument;
  4580 
  4581 * tuned current_goals_markers semantics: begin / end goal avoids
  4582 printing empty lines;
  4583 
  4584 * removed prs and prs_fn hook, which was broken because it did not
  4585 include \n in its semantics, forcing writeln to add one
  4586 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4587 string -> unit if you really want to output text without newline;
  4588 
  4589 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4590 plain output, interface builders may have to enable 'isabelle_font'
  4591 mode to get Isabelle font glyphs as before;
  4592 
  4593 * refined token_translation interface; INCOMPATIBILITY: output length
  4594 now of type real instead of int;
  4595 
  4596 * theory loader actions may be traced via new ThyInfo.add_hook
  4597 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4598 your own database of information attached to *whole* theories -- as
  4599 opposed to intra-theory data slots offered via TheoryDataFun;
  4600 
  4601 * proper handling of dangling sort hypotheses (at last!);
  4602 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4603 extra sort hypotheses that can be witnessed from the type signature;
  4604 the force_strip_shyps flag is gone, any remaining shyps are simply
  4605 left in the theorem (with a warning issued by strip_shyps_warning);
  4606 
  4607 
  4608 
  4609 New in Isabelle98-1 (October 1998)
  4610 ----------------------------------
  4611 
  4612 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4613 
  4614 * several changes of automated proof tools;
  4615 
  4616 * HOL: major changes to the inductive and datatype packages, including
  4617 some minor incompatibilities of theory syntax;
  4618 
  4619 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4620 called `inj_on';
  4621 
  4622 * HOL: removed duplicate thms in Arith:
  4623   less_imp_add_less  should be replaced by  trans_less_add1
  4624   le_imp_add_le      should be replaced by  trans_le_add1
  4625 
  4626 * HOL: unary minus is now overloaded (new type constraints may be
  4627 required);
  4628 
  4629 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4630 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4631 now taken as an integer constant.
  4632 
  4633 * Pure: ML function 'theory_of' renamed to 'theory';
  4634 
  4635 
  4636 *** Proof tools ***
  4637 
  4638 * Simplifier:
  4639   1. Asm_full_simp_tac is now more aggressive.
  4640      1. It will sometimes reorient premises if that increases their power to
  4641         simplify.
  4642      2. It does no longer proceed strictly from left to right but may also
  4643         rotate premises to achieve further simplification.
  4644      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4645      old Asm_full_simp_tac in that it does not rotate premises.
  4646   2. The simplifier now knows a little bit about nat-arithmetic.
  4647 
  4648 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4649 allows for selected deletion of wrappers, by introduction of names for
  4650 wrapper functionals.  This implies that addbefore, addSbefore,
  4651 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4652 and that adding two tactics with the same name overwrites the first
  4653 one (emitting a warning).
  4654   type wrapper = (int -> tactic) -> (int -> tactic)
  4655   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4656   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4657   delWrapper, delSWrapper: claset *  string            -> claset
  4658   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4659 
  4660 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4661 semantics; addbefore now affects only the unsafe part of step_tac
  4662 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4663 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4664 by Force_tac;
  4665 
  4666 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4667 compWrapper; added safe wrapper (and access functions for it);
  4668 
  4669 * HOL/split_all_tac is now much faster and fails if there is nothing
  4670 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4671 and the names of the automatically generated variables have changed.
  4672 split_all_tac has moved within claset() from unsafe wrappers to safe
  4673 wrappers, which means that !!-bound variables are split much more
  4674 aggressively, and safe_tac and clarify_tac now split such variables.
  4675 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4676 Note: the same holds for record_split_tac, which does the job of
  4677 split_all_tac for record fields.
  4678 
  4679 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4680 permanently to the default simpset using Addsplits just like
  4681 Addsimps. They can be removed via Delsplits just like
  4682 Delsimps. Lower-case versions are also available.
  4683 
  4684 * HOL/Simplifier: The rule split_if is now part of the default
  4685 simpset. This means that the simplifier will eliminate all occurrences
  4686 of if-then-else in the conclusion of a goal. To prevent this, you can
  4687 either remove split_if completely from the default simpset by
  4688 `Delsplits [split_if]' or remove it in a specific call of the
  4689 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4690 other case splitting rules to/from the default simpset: every datatype
  4691 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4692 t is the name of the datatype).
  4693 
  4694 * Classical reasoner / Simplifier combination: new force_tac (and
  4695 derivatives Force_tac, force) combines rewriting and classical
  4696 reasoning (and whatever other tools) similarly to auto_tac, but is
  4697 aimed to solve the given subgoal completely.
  4698 
  4699 
  4700 *** General ***
  4701 
  4702 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4703 and `goalw': the theory is no longer needed as an explicit argument -
  4704 the current theory context is used; assumptions are no longer returned
  4705 at the ML-level unless one of them starts with ==> or !!; it is
  4706 recommended to convert to these new commands using isatool fixgoal
  4707 (backup your sources first!);
  4708 
  4709 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4710 the current theory context, and 'theory' to lookup stored theories;
  4711 
  4712 * new theory section 'locale' for declaring constants, assumptions and
  4713 definitions that have local scope;
  4714 
  4715 * new theory section 'nonterminals' for purely syntactic types;
  4716 
  4717 * new theory section 'setup' for generic ML setup functions
  4718 (e.g. package initialization);
  4719 
  4720 * the distribution now includes Isabelle icons: see
  4721 lib/logo/isabelle-{small,tiny}.xpm;
  4722 
  4723 * isatool install - install binaries with absolute references to
  4724 ISABELLE_HOME/bin;
  4725 
  4726 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4727 
  4728 * print mode 'emacs' reserved for Isamode;
  4729 
  4730 * support multiple print (ast) translations per constant name;
  4731 
  4732 * theorems involving oracles are now printed with a suffixed [!];
  4733 
  4734 
  4735 *** HOL ***
  4736 
  4737 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4738 
  4739 * HOL/inductive package reorganized and improved: now supports mutual
  4740 definitions such as
  4741 
  4742   inductive EVEN ODD
  4743     intrs
  4744       null "0 : EVEN"
  4745       oddI "n : EVEN ==> Suc n : ODD"
  4746       evenI "n : ODD ==> Suc n : EVEN"
  4747 
  4748 new theorem list "elims" contains an elimination rule for each of the
  4749 recursive sets; inductive definitions now handle disjunctive premises
  4750 correctly (also ZF);
  4751 
  4752 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4753 "mutual_induct" no longer exists - the induction rule is always
  4754 contained in "induct";
  4755 
  4756 
  4757 * HOL/datatype package re-implemented and greatly improved: now
  4758 supports mutually recursive datatypes such as
  4759 
  4760   datatype
  4761     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4762             | SUM ('a aexp) ('a aexp)
  4763             | DIFF ('a aexp) ('a aexp)
  4764             | NUM 'a
  4765   and
  4766     'a bexp = LESS ('a aexp) ('a aexp)
  4767             | AND ('a bexp) ('a bexp)
  4768             | OR ('a bexp) ('a bexp)
  4769 
  4770 as well as indirectly recursive datatypes such as
  4771 
  4772   datatype
  4773     ('a, 'b) term = Var 'a
  4774                   | App 'b ((('a, 'b) term) list)
  4775 
  4776 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4777 induction on mutually / indirectly recursive datatypes.
  4778 
  4779 Primrec equations are now stored in theory and can be accessed via
  4780 <function_name>.simps.
  4781 
  4782 INCOMPATIBILITIES:
  4783 
  4784   - Theories using datatypes must now have theory Datatype as an
  4785     ancestor.
  4786   - The specific <typename>.induct_tac no longer exists - use the
  4787     generic induct_tac instead.
  4788   - natE has been renamed to nat.exhaust - use exhaust_tac
  4789     instead of res_inst_tac ... natE. Note that the variable
  4790     names in nat.exhaust differ from the names in natE, this
  4791     may cause some "fragile" proofs to fail.
  4792   - The theorems split_<typename>_case and split_<typename>_case_asm
  4793     have been renamed to <typename>.split and <typename>.split_asm.
  4794   - Since default sorts of type variables are now handled correctly,
  4795     some datatype definitions may have to be annotated with explicit
  4796     sort constraints.
  4797   - Primrec definitions no longer require function name and type
  4798     of recursive argument.
  4799 
  4800 Consider using isatool fixdatatype to adapt your theories and proof
  4801 scripts to the new package (backup your sources first!).
  4802 
  4803 
  4804 * HOL/record package: considerably improved implementation; now
  4805 includes concrete syntax for record types, terms, updates; theorems
  4806 for surjective pairing and splitting !!-bound record variables; proof
  4807 support is as follows:
  4808 
  4809   1) standard conversions (selectors or updates applied to record
  4810 constructor terms) are part of the standard simpset;
  4811 
  4812   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4813 made part of standard simpset and claset via addIffs;
  4814 
  4815   3) a tactic for record field splitting (record_split_tac) is part of
  4816 the standard claset (addSWrapper);
  4817 
  4818 To get a better idea about these rules you may retrieve them via
  4819 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4820 the name of your record type.
  4821 
  4822 The split tactic 3) conceptually simplifies by the following rule:
  4823 
  4824   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4825 
  4826 Thus any record variable that is bound by meta-all will automatically
  4827 blow up into some record constructor term, consequently the
  4828 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4829 solve record problems automatically.
  4830 
  4831 
  4832 * reorganized the main HOL image: HOL/Integ and String loaded by
  4833 default; theory Main includes everything;
  4834 
  4835 * automatic simplification of integer sums and comparisons, using cancellation;
  4836 
  4837 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4838 
  4839 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4840 
  4841 * many new identities for unions, intersections, set difference, etc.;
  4842 
  4843 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4844 called split_if, split_split, split_sum_case and split_nat_case (to go
  4845 with add/delsplits);
  4846 
  4847 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4848 (?x::unit) = (); this is made part of the default simpset, which COULD
  4849 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4850 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4851 unit_abs_eta_conv is added in order to counter the effect of
  4852 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4853 %u.f();
  4854 
  4855 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4856 makes more sense);
  4857 
  4858 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4859   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4860   disjointness reasoning but breaking a few old proofs.
  4861 
  4862 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4863 to 'converse' from 'inverse' (for compatibility with ZF and some
  4864 literature);
  4865 
  4866 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4867 the well-founded relation;
  4868 
  4869 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4870     Compl A.  The "Compl" syntax remains available as input syntax for this
  4871     release ONLY.
  4872 
  4873 * HOL/Update: new theory of function updates:
  4874     f(a:=b) == %x. if x=a then b else f x
  4875 may also be iterated as in f(a:=b,c:=d,...);
  4876 
  4877 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4878 
  4879 * HOL/List:
  4880   - new function list_update written xs[i:=v] that updates the i-th
  4881     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4882   - new function `upt' written [i..j(] which generates the list
  4883     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4884     bound write [i..j], which is a shorthand for [i..j+1(].
  4885   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4886 
  4887 * HOL/Arith:
  4888   - removed 'pred' (predecessor) function;
  4889   - generalized some theorems about n-1;
  4890   - many new laws about "div" and "mod";
  4891   - new laws about greatest common divisors (see theory ex/Primes);
  4892 
  4893 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4894 instead of "inverse";
  4895 
  4896 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4897   of the multiset ordering;
  4898 
  4899 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4900   (not included by default);
  4901 
  4902 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4903 
  4904 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4905   programs, i.e. different program variables may have different types.
  4906 
  4907 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4908   [previously, this check worked only if the rewrite rule was unconditional]
  4909   Now rew can involve either definitions or equalities (either == or =).
  4910 
  4911 
  4912 *** ZF ***
  4913 
  4914 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4915   only the theorems proved on ZF.ML;
  4916 
  4917 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4918   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4919   disjointness reasoning but breaking a few old proofs.
  4920 
  4921 * ZF/Update: new theory of function updates
  4922     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4923   may also be iterated as in f(a:=b,c:=d,...);
  4924 
  4925 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4926 
  4927 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4928   [previously, this check worked only if the rewrite rule was unconditional]
  4929   Now rew can involve either definitions or equalities (either == or =).
  4930 
  4931 * case_tac provided for compatibility with HOL
  4932     (like the old excluded_middle_tac, but with subgoals swapped)
  4933 
  4934 
  4935 *** Internal programming interfaces ***
  4936 
  4937 * Pure: several new basic modules made available for general use, see
  4938 also src/Pure/README;
  4939 
  4940 * improved the theory data mechanism to support encapsulation (data
  4941 kind name replaced by private Object.kind, acting as authorization
  4942 key); new type-safe user interface via functor TheoryDataFun; generic
  4943 print_data function becomes basically useless;
  4944 
  4945 * removed global_names compatibility flag -- all theory declarations
  4946 are qualified by default;
  4947 
  4948 * module Pure/Syntax now offers quote / antiquote translation
  4949 functions (useful for Hoare logic etc. with implicit dependencies);
  4950 see HOL/ex/Antiquote for an example use;
  4951 
  4952 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4953 cterm -> thm;
  4954 
  4955 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4956 subgoal;
  4957 
  4958 * Display.print_goals function moved to Locale.print_goals;
  4959 
  4960 * standard print function for goals supports current_goals_markers
  4961 variable for marking begin of proof, end of proof, start of goal; the
  4962 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4963 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4964 for example;
  4965 
  4966 
  4967 
  4968 New in Isabelle98 (January 1998)
  4969 --------------------------------
  4970 
  4971 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4972 
  4973 * changed lexical syntax of terms / types: dots made part of long
  4974 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4975 
  4976 * simpset (and claset) reference variable replaced by functions
  4977 simpset / simpset_ref;
  4978 
  4979 * no longer supports theory aliases (via merge) and non-trivial
  4980 implicit merge of thms' signatures;
  4981 
  4982 * most internal names of constants changed due to qualified names;
  4983 
  4984 * changed Pure/Sequence interface (see Pure/seq.ML);
  4985 
  4986 
  4987 *** General Changes ***
  4988 
  4989 * hierachically structured name spaces (for consts, types, axms, thms
  4990 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4991 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4992 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4993 long_names for fully qualified output names; NOTE: ML programs
  4994 (special tactics, packages etc.) referring to internal names may have
  4995 to be adapted to cope with fully qualified names; in case of severe
  4996 backward campatibility problems try setting 'global_names' at compile
  4997 time to have enrything declared within a flat name space; one may also
  4998 fine tune name declarations in theories via the 'global' and 'local'
  4999 section;
  5000 
  5001 * reimplemented the implicit simpset and claset using the new anytype
  5002 data filed in signatures; references simpset:simpset ref etc. are
  5003 replaced by functions simpset:unit->simpset and
  5004 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5005 to patch your ML files accordingly;
  5006 
  5007 * HTML output now includes theory graph data for display with Java
  5008 applet or isatool browser; data generated automatically via isatool
  5009 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5010 
  5011 * defs may now be conditional; improved rewrite_goals_tac to handle
  5012 conditional equations;
  5013 
  5014 * defs now admits additional type arguments, using TYPE('a) syntax;
  5015 
  5016 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5017 creates a new theory node; implicit merge of thms' signatures is
  5018 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5019 transfer:theory->thm->thm in (rare) cases;
  5020 
  5021 * improved handling of draft signatures / theories; draft thms (and
  5022 ctyps, cterms) are automatically promoted to real ones;
  5023 
  5024 * slightly changed interfaces for oracles: admit many per theory, named
  5025 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5026 
  5027 * print_goals: optional output of const types (set show_consts and
  5028 show_types);
  5029 
  5030 * improved output of warnings (###) and errors (***);
  5031 
  5032 * subgoal_tac displays a warning if the new subgoal has type variables;
  5033 
  5034 * removed old README and Makefiles;
  5035 
  5036 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5037 
  5038 * removed obsolete init_pps and init_database;
  5039 
  5040 * deleted the obsolete tactical STATE, which was declared by
  5041     fun STATE tacfun st = tacfun st st;
  5042 
  5043 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5044 (which abbreviates $HOME);
  5045 
  5046 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5047 use isatool fixseq to adapt your ML programs (this works for fully
  5048 qualified references to the Sequence structure only!);
  5049 
  5050 * use_thy no longer requires writable current directory; it always
  5051 reloads .ML *and* .thy file, if either one is out of date;
  5052 
  5053 
  5054 *** Classical Reasoner ***
  5055 
  5056 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5057 tactics that use classical reasoning to simplify a subgoal without
  5058 splitting it into several subgoals;
  5059 
  5060 * Safe_tac: like safe_tac but uses the default claset;
  5061 
  5062 
  5063 *** Simplifier ***
  5064 
  5065 * added simplification meta rules:
  5066     (asm_)(full_)simplify: simpset -> thm -> thm;
  5067 
  5068 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5069 logics (again);
  5070 
  5071 * added prems argument to simplification procedures;
  5072 
  5073 * HOL, FOL, ZF: added infix function `addsplits':
  5074   instead of `<simpset> setloop (split_tac <thms>)'
  5075   you can simply write `<simpset> addsplits <thms>'
  5076 
  5077 
  5078 *** Syntax ***
  5079 
  5080 * TYPE('a) syntax for type reflection terms;
  5081 
  5082 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5083 
  5084 * pretty printer: changed order of mixfix annotation preference (again!);
  5085 
  5086 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5087 
  5088 
  5089 *** HOL ***
  5090 
  5091 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5092   with `addloop' of the simplifier to faciliate case splitting in premises.
  5093 
  5094 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5095 
  5096 * HOL/Auth: new protocol proofs including some for the Internet
  5097   protocol TLS;
  5098 
  5099 * HOL/Map: new theory of `maps' a la VDM;
  5100 
  5101 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5102 cancelling out common nat summands from =, <, <= (in)equalities, or
  5103 differences; simplification procedures nat_cancel_factor for
  5104 cancelling common factor from =, <, <= (in)equalities over natural
  5105 sums; nat_cancel contains both kinds of procedures, it is installed by
  5106 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5107 
  5108 * HOL/simplifier: terms of the form
  5109   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5110   are rewritten to
  5111   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5112   and those of the form
  5113   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5114   are rewritten to
  5115   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5116 
  5117 * HOL/datatype
  5118   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5119 
  5120   P(t_case f1 ... fn x) =
  5121      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5122         ...
  5123        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5124      )
  5125 
  5126   and a theorem `split_t_case_asm' of the form
  5127 
  5128   P(t_case f1 ... fn x) =
  5129     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5130         ...
  5131        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5132      )
  5133   which can be added to a simpset via `addsplits'. The existing theorems
  5134   expand_list_case and expand_option_case have been renamed to
  5135   split_list_case and split_option_case.
  5136 
  5137 * HOL/Arithmetic:
  5138   - `pred n' is automatically converted to `n-1'.
  5139     Users are strongly encouraged not to use `pred' any longer,
  5140     because it will disappear altogether at some point.
  5141   - Users are strongly encouraged to write "0 < n" rather than
  5142     "n ~= 0". Theorems and proof tools have been modified towards this
  5143     `standard'.
  5144 
  5145 * HOL/Lists:
  5146   the function "set_of_list" has been renamed "set" (and its theorems too);
  5147   the function "nth" now takes its arguments in the reverse order and
  5148   has acquired the infix notation "!" as in "xs!n".
  5149 
  5150 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5151 
  5152 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5153   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5154 
  5155 * HOL/record: extensible records with schematic structural subtyping
  5156 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5157 still lacks various theorems and concrete record syntax;
  5158 
  5159 
  5160 *** HOLCF ***
  5161 
  5162 * removed "axioms" and "generated by" sections;
  5163 
  5164 * replaced "ops" section by extended "consts" section, which is capable of
  5165   handling the continuous function space "->" directly;
  5166 
  5167 * domain package:
  5168   . proves theorems immediately and stores them in the theory,
  5169   . creates hierachical name space,
  5170   . now uses normal mixfix annotations (instead of cinfix...),
  5171   . minor changes to some names and values (for consistency),
  5172   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5173   . separator between mutual domain defs: changed "," to "and",
  5174   . improved handling of sort constraints;  now they have to
  5175     appear on the left-hand side of the equations only;
  5176 
  5177 * fixed LAM <x,y,zs>.b syntax;
  5178 
  5179 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5180 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5181 
  5182 
  5183 *** FOL and ZF ***
  5184 
  5185 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5186   with `addloop' of the simplifier to faciliate case splitting in premises.
  5187 
  5188 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5189 in HOL, they strip ALL and --> from proved theorems;
  5190 
  5191 
  5192 
  5193 New in Isabelle94-8 (May 1997)
  5194 ------------------------------
  5195 
  5196 *** General Changes ***
  5197 
  5198 * new utilities to build / run / maintain Isabelle etc. (in parts
  5199 still somewhat experimental); old Makefiles etc. still functional;
  5200 
  5201 * new 'Isabelle System Manual';
  5202 
  5203 * INSTALL text, together with ./configure and ./build scripts;
  5204 
  5205 * reimplemented type inference for greater efficiency, better error
  5206 messages and clean internal interface;
  5207 
  5208 * prlim command for dealing with lots of subgoals (an easier way of
  5209 setting goals_limit);
  5210 
  5211 
  5212 *** Syntax ***
  5213 
  5214 * supports alternative (named) syntax tables (parser and pretty
  5215 printer); internal interface is provided by add_modesyntax(_i);
  5216 
  5217 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5218 be used in conjunction with the Isabelle symbol font; uses the
  5219 "symbols" syntax table;
  5220 
  5221 * added token_translation interface (may translate name tokens in
  5222 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5223 the current print_mode); IMPORTANT: user print translation functions
  5224 are responsible for marking newly introduced bounds
  5225 (Syntax.mark_boundT);
  5226 
  5227 * token translations for modes "xterm" and "xterm_color" that display
  5228 names in bold, underline etc. or colors (which requires a color
  5229 version of xterm);
  5230 
  5231 * infixes may now be declared with names independent of their syntax;
  5232 
  5233 * added typed_print_translation (like print_translation, but may
  5234 access type of constant);
  5235 
  5236 
  5237 *** Classical Reasoner ***
  5238 
  5239 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5240 some limitations.  Blast_tac...
  5241   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5242   + ignores elimination rules that don't have the correct format
  5243         (the conclusion MUST be a formula variable)
  5244   + ignores types, which can make HOL proofs fail
  5245   + rules must not require higher-order unification, e.g. apply_type in ZF
  5246     [message "Function Var's argument not a bound variable" relates to this]
  5247   + its proof strategy is more general but can actually be slower
  5248 
  5249 * substitution with equality assumptions no longer permutes other
  5250 assumptions;
  5251 
  5252 * minor changes in semantics of addafter (now called addaltern); renamed
  5253 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5254 (and access functions for it);
  5255 
  5256 * improved combination of classical reasoner and simplifier:
  5257   + functions for handling clasimpsets
  5258   + improvement of addss: now the simplifier is called _after_ the
  5259     safe steps.
  5260   + safe variant of addss called addSss: uses safe simplifications
  5261     _during_ the safe steps. It is more complete as it allows multiple
  5262     instantiations of unknowns (e.g. with slow_tac).
  5263 
  5264 *** Simplifier ***
  5265 
  5266 * added interface for simplification procedures (functions that
  5267 produce *proven* rewrite rules on the fly, depending on current
  5268 redex);
  5269 
  5270 * ordering on terms as parameter (used for ordered rewriting);
  5271 
  5272 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5273 
  5274 * the solver is now split into a safe and an unsafe part.
  5275 This should be invisible for the normal user, except that the
  5276 functions setsolver and addsolver have been renamed to setSolver and
  5277 addSolver; added safe_asm_full_simp_tac;
  5278 
  5279 
  5280 *** HOL ***
  5281 
  5282 * a generic induction tactic `induct_tac' which works for all datatypes and
  5283 also for type `nat';
  5284 
  5285 * a generic case distinction tactic `exhaust_tac' which works for all
  5286 datatypes and also for type `nat';
  5287 
  5288 * each datatype comes with a function `size';
  5289 
  5290 * patterns in case expressions allow tuple patterns as arguments to
  5291 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5292 
  5293 * primrec now also works with type nat;
  5294 
  5295 * recdef: a new declaration form, allows general recursive functions to be
  5296 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5297 
  5298 * the constant for negation has been renamed from "not" to "Not" to
  5299 harmonize with FOL, ZF, LK, etc.;
  5300 
  5301 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5302 infinite lists;
  5303 
  5304 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5305 
  5306 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5307 problems in commutative rings, using axiomatic type classes for + and *;
  5308 
  5309 * more examples in HOL/MiniML and HOL/Auth;
  5310 
  5311 * more default rewrite rules for quantifiers, union/intersection;
  5312 
  5313 * a new constant `arbitrary == @x.False';
  5314 
  5315 * HOLCF/IOA replaces old HOL/IOA;
  5316 
  5317 * HOLCF changes: derived all rules and arities
  5318   + axiomatic type classes instead of classes
  5319   + typedef instead of faking type definitions
  5320   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5321   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5322   + eliminated the types void, one, tr
  5323   + use unit lift and bool lift (with translations) instead of one and tr
  5324   + eliminated blift from Lift3.thy (use Def instead of blift)
  5325   all eliminated rules are derived as theorems --> no visible changes ;
  5326 
  5327 
  5328 *** ZF ***
  5329 
  5330 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5331 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5332 as ZF_cs addSIs [equalityI];
  5333 
  5334 
  5335 
  5336 New in Isabelle94-7 (November 96)
  5337 ---------------------------------
  5338 
  5339 * allowing negative levels (as offsets) in prlev and choplev;
  5340 
  5341 * super-linear speedup for large simplifications;
  5342 
  5343 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5344 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5345 FAIL); can suppress it using the command Delsimps (ex_simps @
  5346 all_simps); De Morgan laws are also now included, by default;
  5347 
  5348 * improved printing of ==>  :  ~:
  5349 
  5350 * new object-logic "Sequents" adds linear logic, while replacing LK
  5351 and Modal (thanks to Sara Kalvala);
  5352 
  5353 * HOL/Auth: correctness proofs for authentication protocols;
  5354 
  5355 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5356 examples on HOL/Auth);
  5357 
  5358 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5359 the rewriter and classical reasoner simultaneously;
  5360 
  5361 * function uresult no longer returns theorems in "standard" format;
  5362 regain previous version by: val uresult = standard o uresult;
  5363 
  5364 
  5365 
  5366 New in Isabelle94-6
  5367 -------------------
  5368 
  5369 * oracles -- these establish an interface between Isabelle and trusted
  5370 external reasoners, which may deliver results as theorems;
  5371 
  5372 * proof objects (in particular record all uses of oracles);
  5373 
  5374 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5375 
  5376 * "constdefs" section in theory files;
  5377 
  5378 * "primrec" section (HOL) no longer requires names;
  5379 
  5380 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5381 
  5382 
  5383 
  5384 New in Isabelle94-5
  5385 -------------------
  5386 
  5387 * reduced space requirements;
  5388 
  5389 * automatic HTML generation from theories;
  5390 
  5391 * theory files no longer require "..." (quotes) around most types;
  5392 
  5393 * new examples, including two proofs of the Church-Rosser theorem;
  5394 
  5395 * non-curried (1994) version of HOL is no longer distributed;
  5396 
  5397 
  5398 
  5399 New in Isabelle94-4
  5400 -------------------
  5401 
  5402 * greatly reduced space requirements;
  5403 
  5404 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5405 
  5406 * searchable theorem database (see the section "Retrieving theorems" on
  5407 page 8 of the Reference Manual);
  5408 
  5409 * new examples, including Grabczewski's monumental case study of the
  5410 Axiom of Choice;
  5411 
  5412 * The previous version of HOL renamed to Old_HOL;
  5413 
  5414 * The new version of HOL (previously called CHOL) uses a curried syntax
  5415 for functions.  Application looks like f a b instead of f(a,b);
  5416 
  5417 * Mutually recursive inductive definitions finally work in HOL;
  5418 
  5419 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5420 translates to the operator "split";
  5421 
  5422 
  5423 
  5424 New in Isabelle94-3
  5425 -------------------
  5426 
  5427 * new infix operator, addss, allowing the classical reasoner to
  5428 perform simplification at each step of its search.  Example:
  5429         fast_tac (cs addss ss)
  5430 
  5431 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5432 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5433 look like (a,b) instead of <a,b>;
  5434 
  5435 * PLEASE NOTE: CHOL will eventually replace HOL!
  5436 
  5437 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5438 It translates to the operator "split".  A new theory of integers is available;
  5439 
  5440 * In ZF, integer numerals now denote two's-complement binary integers.
  5441 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5442 
  5443 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5444 of the Axiom of Choice;
  5445 
  5446 
  5447 
  5448 New in Isabelle94-2
  5449 -------------------
  5450 
  5451 * Significantly faster resolution;
  5452 
  5453 * the different sections in a .thy file can now be mixed and repeated
  5454 freely;
  5455 
  5456 * Database of theorems for FOL, HOL and ZF.  New
  5457 commands including qed, qed_goal and bind_thm store theorems in the database.
  5458 
  5459 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5460 a given theory (thms_of), or find out what theory a theorem was proved in
  5461 (theory_of_thm);
  5462 
  5463 * Bugs fixed in the inductive definition and datatype packages;
  5464 
  5465 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5466 and HOL_dup_cs obsolete;
  5467 
  5468 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5469 have been removed;
  5470 
  5471 * Simpler definition of function space in ZF;
  5472 
  5473 * new results about cardinal and ordinal arithmetic in ZF;
  5474 
  5475 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5476 types;
  5477 
  5478 :mode=text:wrap=hard:maxLineLen=72:
  5479 
  5480 $Id$