NEWS
author wenzelm
Tue Jun 03 00:20:22 2008 +0200 (2008-06-03)
changeset 27061 a057cb0d7d55
parent 27008 9e39f5403db7
child 27067 f8a7aff41acb
permissions -rw-r--r--
reorganized isar-ref;
     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 * Syntax: symbol \<chi> is now considered a letter.  Potential
    13 INCOMPATIBILITY in identifier syntax etc.
    14 
    15 * Outer syntax: string tokens may contain arbitrary character codes
    16 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
    17 "foo_bar".
    18 
    19 * Outer syntax: string tokens no longer admit escaped white space,
    20 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
    21 white space directly.
    22 
    23 * Theory loader: use_thy (and similar operations) no longer set the
    24 implicit ML context, which was occasionally hard to predict and in
    25 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
    26 provides a proper context already.
    27 
    28 * Theory loader: old-style ML proof scripts being *attached* to a thy
    29 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
    30 'use' within a theory file will do the job.
    31 
    32 * Name space merge now observes canonical order, i.e. the second space
    33 is inserted into the first one, while existing entries in the first
    34 space take precedence.  INCOMPATIBILITY in rare situations, may try to
    35 swap theory imports.
    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 HOL/Complex/Complex.thy for an Isar example and
    98 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 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   135 
   136   INCOMPATIBILITIES:
   137 
   138   - Definitions of overloaded constants on sets have to be replaced by
   139     definitions on => and bool.
   140 
   141   - Some definitions of overloaded operators on sets can now be proved
   142     using the definitions of the operators on => and bool.  Therefore,
   143     the following theorems have been renamed:
   144 
   145       subset_def   -> subset_eq
   146       psubset_def  -> psubset_eq
   147       set_diff_def -> set_diff_eq
   148       Compl_def    -> Compl_eq
   149       Sup_set_def  -> Sup_set_eq
   150       Inf_set_def  -> Inf_set_eq
   151       sup_set_def  -> sup_set_eq
   152       inf_set_def  -> inf_set_eq
   153 
   154   - Due to the incompleteness of the HO unification algorithm, some
   155     rules such as subst may require manual instantiation, if some of
   156     the unknowns in the rule is a set.
   157 
   158   - Higher order unification and forward proofs:
   159     The proof pattern
   160 
   161       have "P (S::'a set)" <...>
   162       then have "EX S. P S" ..
   163 
   164     no longer works (due to the incompleteness of the HO unification
   165     algorithm) and must be replaced by the pattern
   166 
   167       have "EX S. P S"
   168       proof
   169         show "P S" <...>
   170       qed
   171 
   172   - Calculational reasoning with subst (or similar rules):
   173     The proof pattern
   174 
   175       have "P (S::'a set)" <...>
   176       also have "S = T" <...>
   177       finally have "P T" .
   178 
   179     no longer works (for similar reasons as the previous example) and
   180     must be replaced by something like
   181 
   182       have "P (S::'a set)" <...>
   183       moreover have "S = T" <...>
   184       ultimately have "P T" by simp
   185 
   186   - Tactics or packages written in ML code:
   187     Code performing pattern matching on types via
   188 
   189       Type ("set", [T]) => ...
   190 
   191     must be rewritten. Moreover, functions like strip_type or
   192     binder_types no longer return the right value when applied to a
   193     type of the form
   194 
   195       T1 => ... => Tn => U => bool
   196 
   197     rather than
   198 
   199       T1 => ... => Tn => U set
   200 
   201 * Merged theories Wellfounded_Recursion, Accessible_Part and
   202 Wellfounded_Relations to "Wellfounded.thy".
   203 
   204 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   205 
   206 * Class finite no longer treats UNIV as class parameter.  Use class
   207 enum from theory Library/Enum instead to achieve a similar effect.
   208 INCOMPATIBILITY.
   209 
   210 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   211 and "Cons".  INCOMPATIBILITY.
   212 
   213 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   214 Potential INCOMPATIBILITY.
   215 
   216 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   217 injective_fst_snd removed, use split_eta and prod_eqI instead.
   218 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   219 
   220 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   221 the same name in theory Orderings:
   222 
   223   less_trans
   224   less_linear
   225   le_imp_less_or_eq
   226   le_less_trans
   227   less_le_trans
   228   less_not_sym
   229   less_asym
   230 
   231 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   232 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   233 and different variable names.
   234 
   235 * Library/Option_ord.thy: Canonical order on option type.
   236 
   237 * Library/RBT.thy: Red-black trees, an efficient implementation of
   238 finite maps.
   239 
   240 * Library/Countable.thy: Type class for countable types.
   241 
   242 * Theory Int: The representation of numerals has changed.  The infix
   243 operator BIT and the bit datatype with constructors B0 and B1 have
   244 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   245 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   246 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   247 accordingly.
   248 
   249 * Theory Nat: definition of <= and < on natural numbers no longer
   250 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   251 le_def and less_def have disappeared.  Consider lemmas not_less
   252 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   253 
   254 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   255 (whose purpose mainly is for various fold_set functionals) have been
   256 abandoned in favor of the existing algebraic classes
   257 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   258 lower_semilattice (resp. upper_semilattice) and linorder.
   259 INCOMPATIBILITY.
   260 
   261 * Theory Transitive_Closure: induct and cases rules now declare proper
   262 case_names ("base" and "step").  INCOMPATIBILITY.
   263 
   264 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   265 lattices.  The form set-specific version is available as
   266 Inductive.lfp_ordinal_induct_set.
   267 
   268 * Renamed theorems "power.simps" to "power_int.simps".
   269 
   270 * Class semiring_div provides basic abstract properties of semirings
   271 with division and modulo operations.  Subsumes former class dvd_mod.
   272 
   273 * Merged theories IntDef, Numeral and IntArith into unified theory
   274 Int.  INCOMPATIBILITY.
   275 
   276 * Theory Library/Code_Index: type "index" now represents natural
   277 numbers rather than integers.  INCOMPATIBILITY.
   278 
   279 * New class "uminus" with operation "uminus" (split of from class
   280 "minus" which now only has operation "minus", binary).
   281 INCOMPATIBILITY.
   282 
   283 * New primrec package.  Specification syntax conforms in style to
   284 definition/function/....  No separate induction rule is provided.  The
   285 "primrec" command distinguishes old-style and new-style specifications
   286 by syntax.  The former primrec package is now named OldPrimrecPackage.
   287 When adjusting theories, beware: constants stemming from new-style
   288 primrec specifications have authentic syntax.
   289 
   290 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   291 
   292 * Library/ListVector: new theory of arithmetic vector operations.
   293 
   294 * Library/Order_Relation: new theory of various orderings as sets of
   295 pairs.  Defines preorders, partial orders, linear orders and
   296 well-orders on sets and on types.
   297 
   298 * Constants "card", "internal_split", "option_map" now with authentic
   299 syntax.  INCOMPATIBILITY.
   300 
   301 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   302 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   303 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   304 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   305 Sup_set_def, le_def, less_def, option_map_def now with object
   306 equality.  INCOMPATIBILITY.
   307 
   308 * Method "induction_scheme" derives user-specified induction rules
   309 from well-founded induction and completeness of patterns. This factors
   310 out some operations that are done internally by the function package
   311 and makes them available separately. See "HOL/ex/Induction_Scheme.thy"
   312 for examples,
   313 
   314 * Records. Removed K_record, and replaced it by pure lambda term
   315 %x. c. The simplifier setup is now more robust against eta expansion.
   316 INCOMPATIBILITY: in cases explicitly referring to K_record.
   317 
   318 * Metis prover is now an order of magnitude faster, and also works
   319 with multithreading.
   320 
   321 * Metis: the maximum number of clauses that can be produced from a
   322 theorem is now given by the attribute max_clauses. Theorems that
   323 exceed this number are ignored, with a warning printed.
   324 
   325 * Sledgehammer no longer produces structured proofs by default. To
   326 enable, declare [[sledgehammer_full = true]]. Attributes
   327 reconstruction_modulus, reconstruction_sorts renamed
   328 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   329 
   330 * More flexible generation of measure functions for termination
   331 proofs: Measure functions can be declared by proving a rule of the
   332 form "is_measure f" and giving it the [measure_function] attribute.
   333 The "is_measure" predicate is logically meaningless (always true), and
   334 just guides the heuristic.  To find suitable measure functions, the
   335 termination prover sets up the goal "is_measure ?f" of the appropriate
   336 type and generates all solutions by prolog-style backwards proof using
   337 the declared rules.
   338 
   339 This setup also deals with rules like 
   340 
   341   "is_measure f ==> is_measure (list_size f)"
   342 
   343 which accomodates nested datatypes that recurse through lists. Similar
   344 rules are predeclared for products and option types.
   345 
   346 
   347 *** ZF ***
   348 
   349 * Renamed some theories to allow to loading both ZF and HOL in the
   350 same session:
   351 
   352   Datatype  -> Datatype_ZF
   353   Inductive -> Inductive_ZF
   354   Int       -> Int_ZF
   355   IntDiv    -> IntDiv_ZF
   356   Nat       -> Nat_ZF
   357   List      -> List_ZF
   358   Main      -> Main_ZF
   359 
   360 INCOMPATIBILITY: ZF theories that import individual theories below
   361 Main might need to be adapted.  Regular theory Main is still
   362 available, as trivial extension of Main_ZF.
   363 
   364 
   365 *** ML ***
   366 
   367 * Functor NamedThmsFun: data is available to the user as dynamic fact
   368 (of the same name).  Removed obsolete print command.
   369 
   370 * Removed obsolete "use_legacy_bindings" function.  INCOMPATIBILITY.
   371 
   372 * ML within Isar: antiquotation @{const name} or @{const
   373 name(typargs)} produces statically-checked Const term.
   374 
   375 * The ``print mode'' is now a thread-local value derived from a global
   376 template (the former print_mode reference), thus access becomes
   377 non-critical.  The global print_mode reference is for session
   378 management only; user-code should use print_mode_value,
   379 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   380 
   381 * Functions system/system_out provide a robust way to invoke external
   382 shell commands, with propagation of interrupts (requires Poly/ML 5.2).
   383 Do not use OS.Process.system etc. from the basis library!
   384 
   385 
   386 *** System ***
   387 
   388 * YXML notation provides a simple and efficient alternative to
   389 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   390 isatool yxml as described in the Isabelle system manual.
   391 
   392 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   393 way of changing the user's settings is via
   394 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   395 script.
   396 
   397 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   398 in accordance with Proof General 3.7, which prefers GNU emacs.
   399 
   400 * Multithreading.max_threads := 0 refers to the number of actual CPU
   401 cores of the underlying machine, which is a good starting point for
   402 optimal performance tuning.  The corresponding usedir option -M allows
   403 "max" as an alias for "0".  WARNING: does not work on certain versions
   404 of Mac OS (with Poly/ML 5.1).
   405 
   406 * isatool tty runs Isabelle process with plain tty interaction;
   407 optional line editor may be specified via ISABELLE_LINE_EDITOR
   408 setting, the default settings attempt to locate "ledit" and "rlwrap".
   409 
   410 * isatool browser now works with Cygwin as well, using general
   411 "javapath" function defined in Isabelle process environment.
   412 
   413 * isabelle-process: non-ML sessions are run with "nice", to prevent
   414 Isabelle from flooding interactive front-ends (notably ProofGeneral /
   415 XEmacs).
   416 
   417 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   418 provides general wrapper for managing an Isabelle process in a robust
   419 fashion, with ``cooked'' output from stdin/stderr.
   420 
   421 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   422 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   423 
   424 
   425 
   426 New in Isabelle2007 (November 2007)
   427 -----------------------------------
   428 
   429 *** General ***
   430 
   431 * More uniform information about legacy features, notably a
   432 warning/error of "Legacy feature: ...", depending on the state of the
   433 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   434 legacy features will disappear eventually.
   435 
   436 * Theory syntax: the header format ``theory A = B + C:'' has been
   437 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   438 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   439 
   440 * Theory syntax: the old non-Isar theory file format has been
   441 discontinued altogether.  Note that ML proof scripts may still be used
   442 with Isar theories; migration is usually quite simple with the ML
   443 function use_legacy_bindings.  INCOMPATIBILITY.
   444 
   445 * Theory syntax: some popular names (e.g. 'class', 'declaration',
   446 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
   447 quotes.
   448 
   449 * Theory loader: be more serious about observing the static theory
   450 header specifications (including optional directories), but not the
   451 accidental file locations of previously successful loads.  The strict
   452 update policy of former update_thy is now already performed by
   453 use_thy, so the former has been removed; use_thys updates several
   454 theories simultaneously, just as 'imports' within a theory header
   455 specification, but without merging the results.  Potential
   456 INCOMPATIBILITY: may need to refine theory headers and commands
   457 ROOT.ML which depend on load order.
   458 
   459 * Theory loader: optional support for content-based file
   460 identification, instead of the traditional scheme of full physical
   461 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
   462 (cf. the system manual).  The new scheme allows to work with
   463 non-finished theories in persistent session images, such that source
   464 files may be moved later on without requiring reloads.
   465 
   466 * Theory loader: old-style ML proof scripts being *attached* to a thy
   467 file (with the same base name as the theory) are considered a legacy
   468 feature, which will disappear eventually. Even now, the theory loader
   469 no longer maintains dependencies on such files.
   470 
   471 * Syntax: the scope for resolving ambiguities via type-inference is
   472 now limited to individual terms, instead of whole simultaneous
   473 specifications as before. This greatly reduces the complexity of the
   474 syntax module and improves flexibility by separating parsing and
   475 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
   476 'fixes' etc.) are required in rare situations.
   477 
   478 * Syntax: constants introduced by new-style packages ('definition',
   479 'abbreviation' etc.) are passed through the syntax module in
   480 ``authentic mode''. This means that associated mixfix annotations
   481 really stick to such constants, independently of potential name space
   482 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   483 trees are represented slightly differently, may need to adapt syntax
   484 translations accordingly. Use CONST marker in 'translations' and
   485 @{const_syntax} antiquotation in 'parse_translation' etc.
   486 
   487 * Legacy goal package: reduced interface to the bare minimum required
   488 to keep existing proof scripts running.  Most other user-level
   489 functions are now part of the OldGoals structure, which is *not* open
   490 by default (consider isatool expandshort before open OldGoals).
   491 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   492 these tend to cause confusion about the actual goal (!) context being
   493 used here, which is not necessarily the same as the_context().
   494 
   495 * Command 'find_theorems': supports "*" wild-card in "name:"
   496 criterion; "with_dups" option.  Certain ProofGeneral versions might
   497 support a specific search form (see ProofGeneral/CHANGES).
   498 
   499 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   500 by default, which means that "prems" (and also "fixed variables") are
   501 suppressed from proof state output.  Note that the ProofGeneral
   502 settings mechanism allows to change and save options persistently, but
   503 older versions of Isabelle will fail to start up if a negative prems
   504 limit is imposed.
   505 
   506 * Local theory targets may be specified by non-nested blocks of
   507 ``context/locale/class ... begin'' followed by ``end''.  The body may
   508 contain definitions, theorems etc., including any derived mechanism
   509 that has been implemented on top of these primitives.  This concept
   510 generalizes the existing ``theorem (in ...)'' towards more versatility
   511 and scalability.
   512 
   513 * Proof General interface: proper undo of final 'end' command;
   514 discontinued Isabelle/classic mode (ML proof scripts).
   515 
   516 
   517 *** Document preparation ***
   518 
   519 * Added antiquotation @{theory name} which prints the given name,
   520 after checking that it refers to a valid ancestor theory in the
   521 current context.
   522 
   523 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   524 check the given source text as ML type/structure, printing verbatim.
   525 
   526 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   527 "c args == rhs" given in the current context.  (Any number of
   528 arguments may be given on the LHS.)
   529 
   530 
   531 *** Pure ***
   532 
   533 * The 'class' package offers a combination of axclass and locale to
   534 achieve Haskell-like type classes in Isabelle.  Definitions and
   535 theorems within a class context produce both relative results (with
   536 implicit parameters according to the locale context), and polymorphic
   537 constants with qualified polymorphism (according to the class
   538 context).  Within the body context of a 'class' target, a separate
   539 syntax layer ("user space type system") takes care of converting
   540 between global polymorphic consts and internal locale representation.
   541 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   542 "isatool doc classes" provides a tutorial.
   543 
   544 * Generic code generator framework allows to generate executable
   545 code for ML and Haskell (including Isabelle classes).  A short usage
   546 sketch:
   547 
   548     internal compilation:
   549         export_code <list of constants (term syntax)> in SML
   550     writing SML code to a file:
   551         export_code <list of constants (term syntax)> in SML <filename>
   552     writing OCaml code to a file:
   553         export_code <list of constants (term syntax)> in OCaml <filename>
   554     writing Haskell code to a bunch of files:
   555         export_code <list of constants (term syntax)> in Haskell <filename>
   556 
   557     evaluating closed propositions to True/False using code generation:
   558         method ``eval''
   559 
   560 Reasonable default setup of framework in HOL.
   561 
   562 Theorem attributs for selecting and transforming function equations theorems:
   563 
   564     [code fun]:        select a theorem as function equation for a specific constant
   565     [code fun del]:    deselect a theorem as function equation for a specific constant
   566     [code inline]:     select an equation theorem for unfolding (inlining) in place
   567     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   568 
   569 User-defined serializations (target in {SML, OCaml, Haskell}):
   570 
   571     code_const <and-list of constants (term syntax)>
   572       {(target) <and-list of const target syntax>}+
   573 
   574     code_type <and-list of type constructors>
   575       {(target) <and-list of type target syntax>}+
   576 
   577     code_instance <and-list of instances>
   578       {(target)}+
   579         where instance ::= <type constructor> :: <class>
   580 
   581     code_class <and_list of classes>
   582       {(target) <and-list of class target syntax>}+
   583         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   584 
   585 code_instance and code_class only are effective to target Haskell.
   586 
   587 For example usage see src/HOL/ex/Codegenerator.thy and
   588 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   589 generation from Isabelle/HOL theories is available via "isatool doc
   590 codegen".
   591 
   592 * Code generator: consts in 'consts_code' Isar commands are now
   593 referred to by usual term syntax (including optional type
   594 annotations).
   595 
   596 * Command 'no_translations' removes translation rules from theory
   597 syntax.
   598 
   599 * Overloaded definitions are now actually checked for acyclic
   600 dependencies.  The overloading scheme is slightly more general than
   601 that of Haskell98, although Isabelle does not demand an exact
   602 correspondence to type class and instance declarations.
   603 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   604 exotic versions of overloading -- at the discretion of the user!
   605 
   606 Polymorphic constants are represented via type arguments, i.e. the
   607 instantiation that matches an instance against the most general
   608 declaration given in the signature.  For example, with the declaration
   609 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   610 as c(nat).  Overloading is essentially simultaneous structural
   611 recursion over such type arguments.  Incomplete specification patterns
   612 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   613 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   614 Command 'print_theory' outputs the normalized system of recursive
   615 equations, see section "definitions".
   616 
   617 * Configuration options are maintained within the theory or proof
   618 context (with name and type bool/int/string), providing a very simple
   619 interface to a poor-man's version of general context data.  Tools may
   620 declare options in ML (e.g. using Attrib.config_int) and then refer to
   621 these values using Config.get etc.  Users may change options via an
   622 associated attribute of the same name.  This form of context
   623 declaration works particularly well with commands 'declare' or
   624 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   625 very easy to avoid global references, which would not observe Isar
   626 toplevel undo/redo and fail to work with multithreading.
   627 
   628 Various global ML references of Pure and HOL have been turned into
   629 configuration options:
   630 
   631   Unify.search_bound		unify_search_bound
   632   Unify.trace_bound		unify_trace_bound
   633   Unify.trace_simp		unify_trace_simp
   634   Unify.trace_types		unify_trace_types
   635   Simplifier.simp_depth_limit	simp_depth_limit
   636   Blast.depth_limit		blast_depth_limit
   637   DatatypeProp.dtK		datatype_distinctness_limit
   638   fast_arith_neq_limit  	fast_arith_neq_limit
   639   fast_arith_split_limit	fast_arith_split_limit
   640 
   641 * Named collections of theorems may be easily installed as context
   642 data using the functor NamedThmsFun (see also
   643 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   644 attributes; there is also a toplevel print command.  This facility is
   645 just a common case of general context data, which is the preferred way
   646 for anything more complex than just a list of facts in canonical
   647 order.
   648 
   649 * Isar: command 'declaration' augments a local theory by generic
   650 declaration functions written in ML.  This enables arbitrary content
   651 being added to the context, depending on a morphism that tells the
   652 difference of the original declaration context wrt. the application
   653 context encountered later on.
   654 
   655 * Isar: proper interfaces for simplification procedures.  Command
   656 'simproc_setup' declares named simprocs (with match patterns, and body
   657 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   658 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   659 
   660 * Isar: an extra pair of brackets around attribute declarations
   661 abbreviates a theorem reference involving an internal dummy fact,
   662 which will be ignored later --- only the effect of the attribute on
   663 the background context will persist.  This form of in-place
   664 declarations is particularly useful with commands like 'declare' and
   665 'using', for example ``have A using [[simproc a]] by simp''.
   666 
   667 * Isar: method "assumption" (and implicit closing of subproofs) now
   668 takes simple non-atomic goal assumptions into account: after applying
   669 an assumption as a rule the resulting subgoals are solved by atomic
   670 assumption steps.  This is particularly useful to finish 'obtain'
   671 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   672 without referring to the original premise "!!x. P x ==> thesis" in the
   673 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   674 more permissive.
   675 
   676 * Isar: implicit use of prems from the Isar proof context is
   677 considered a legacy feature.  Common applications like ``have A .''
   678 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   679 referencing facts explicitly here improves readability and
   680 maintainability of proof texts.
   681 
   682 * Isar: improper proof element 'guess' is like 'obtain', but derives
   683 the obtained context from the course of reasoning!  For example:
   684 
   685   assume "EX x y. A x & B y"   -- "any previous fact"
   686   then guess x and y by clarify
   687 
   688 This technique is potentially adventurous, depending on the facts and
   689 proof tools being involved here.
   690 
   691 * Isar: known facts from the proof context may be specified as literal
   692 propositions, using ASCII back-quote syntax.  This works wherever
   693 named facts used to be allowed so far, in proof commands, proof
   694 methods, attributes etc.  Literal facts are retrieved from the context
   695 according to unification of type and term parameters.  For example,
   696 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   697 theorems in the current context, then these are valid literal facts:
   698 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   699 
   700 There is also a proof method "fact" which does the same composition
   701 for explicit goal states, e.g. the following proof texts coincide with
   702 certain special cases of literal facts:
   703 
   704   have "A" by fact                 ==  note `A`
   705   have "A ==> B" by fact           ==  note `A ==> B`
   706   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   707   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   708 
   709 * Isar: ":" (colon) is no longer a symbolic identifier character in
   710 outer syntax.  Thus symbolic identifiers may be used without
   711 additional white space in declarations like this: ``assume *: A''.
   712 
   713 * Isar: 'print_facts' prints all local facts of the current context,
   714 both named and unnamed ones.
   715 
   716 * Isar: 'def' now admits simultaneous definitions, e.g.:
   717 
   718   def x == "t" and y == "u"
   719 
   720 * Isar: added command 'unfolding', which is structurally similar to
   721 'using', but affects both the goal state and facts by unfolding given
   722 rewrite rules.  Thus many occurrences of the 'unfold' method or
   723 'unfolded' attribute may be replaced by first-class proof text.
   724 
   725 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   726 and command 'unfolding' now all support object-level equalities
   727 (potentially conditional).  The underlying notion of rewrite rule is
   728 analogous to the 'rule_format' attribute, but *not* that of the
   729 Simplifier (which is usually more generous).
   730 
   731 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   732 premises of a theorem by n. Useful in conjunction with drule.
   733 
   734 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   735 method expression within a sandbox consisting of the first N
   736 sub-goals, which need to exist.  For example, ``simp_all [3]''
   737 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   738 simplifies all new goals that emerge from applying rule foo to the
   739 originally first one.
   740 
   741 * Isar: schematic goals are no longer restricted to higher-order
   742 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   743 expected.
   744 
   745 * Isar: the conclusion of a long theorem statement is now either
   746 'shows' (a simultaneous conjunction, as before), or 'obtains'
   747 (essentially a disjunction of cases with local parameters and
   748 assumptions).  The latter allows to express general elimination rules
   749 adequately; in this notation common elimination rules look like this:
   750 
   751   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   752     assumes "EX x. P x"
   753     obtains x where "P x"
   754 
   755   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   756     assumes "A & B"
   757     obtains A and B
   758 
   759   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   760     assumes "A | B"
   761     obtains
   762       A
   763     | B
   764 
   765 The subsequent classical rules even refer to the formal "thesis"
   766 explicitly:
   767 
   768   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   769     obtains "~ thesis"
   770 
   771   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   772     obtains "thesis ==> something"
   773 
   774 The actual proof of an 'obtains' statement is analogous to that of the
   775 Isar proof element 'obtain', only that there may be several cases.
   776 Optional case names may be specified in parentheses; these will be
   777 available both in the present proof and as annotations in the
   778 resulting rule, for later use with the 'cases' method (cf. attribute
   779 case_names).
   780 
   781 * Isar: the assumptions of a long theorem statement are available as
   782 "assms" fact in the proof context.  This is more appropriate than the
   783 (historical) "prems", which refers to all assumptions of the current
   784 context, including those from the target locale, proof body etc.
   785 
   786 * Isar: 'print_statement' prints theorems from the current theory or
   787 proof context in long statement form, according to the syntax of a
   788 top-level lemma.
   789 
   790 * Isar: 'obtain' takes an optional case name for the local context
   791 introduction rule (default "that").
   792 
   793 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   794 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   795 to occur.
   796 
   797 * Pure: syntax "CONST name" produces a fully internalized constant
   798 according to the current context.  This is particularly useful for
   799 syntax translations that should refer to internal constant
   800 representations independently of name spaces.
   801 
   802 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   803 instead of "FOO ". This allows multiple binder declarations to coexist
   804 in the same context.  INCOMPATIBILITY.
   805 
   806 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   807 primitive that also works in a locale context (both for constants and
   808 fixed variables). Type declaration and internal syntactic representation
   809 of given constants retrieved from the context. Likewise, the
   810 'no_notation' command allows to remove given syntax annotations from the
   811 current context.
   812 
   813 * Isar/locales: new derived specification elements 'axiomatization',
   814 'definition', 'abbreviation', which support type-inference, admit
   815 object-level specifications (equality, equivalence).  See also the
   816 isar-ref manual.  Examples:
   817 
   818   axiomatization
   819     eq  (infix "===" 50) where
   820     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   821 
   822   definition "f x y = x + y + 1"
   823   definition g where "g x = f x x"
   824 
   825   abbreviation
   826     neq  (infix "=!=" 50) where
   827     "x =!= y == ~ (x === y)"
   828 
   829 These specifications may be also used in a locale context.  Then the
   830 constants being introduced depend on certain fixed parameters, and the
   831 constant name is qualified by the locale base name.  An internal
   832 abbreviation takes care for convenient input and output, making the
   833 parameters implicit and using the original short name.  See also
   834 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   835 entities from a monomorphic theory.
   836 
   837 Presently, abbreviations are only available 'in' a target locale, but
   838 not inherited by general import expressions.  Also note that
   839 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   840 'translations' in common applications.  The "no_abbrevs" print mode
   841 prevents folding of abbreviations in term output.
   842 
   843 Concrete syntax is attached to specified constants in internal form,
   844 independently of name spaces.  The parse tree representation is
   845 slightly different -- use 'notation' instead of raw 'syntax', and
   846 'translations' with explicit "CONST" markup to accommodate this.
   847 
   848 * Pure/Isar: unified syntax for new-style specification mechanisms
   849 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   850 full type inference and dummy patterns ("_").  For example:
   851 
   852   definition "K x _ = x"
   853 
   854   inductive conj for A B
   855   where "A ==> B ==> conj A B"
   856 
   857 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   858 the current context.  Print mode "no_abbrevs" prevents inversion of
   859 abbreviations on output.
   860 
   861 * Isar/locales: improved parameter handling: use of locales "var" and
   862 "struct" no longer necessary; - parameter renamings are no longer
   863 required to be injective.  For example, this allows to define
   864 endomorphisms as locale endom = homom mult mult h.
   865 
   866 * Isar/locales: changed the way locales with predicates are defined.
   867 Instead of accumulating the specification, the imported expression is
   868 now an interpretation.  INCOMPATIBILITY: different normal form of
   869 locale expressions.  In particular, in interpretations of locales with
   870 predicates, goals repesenting already interpreted fragments are not
   871 removed automatically.  Use methods `intro_locales' and
   872 `unfold_locales'; see below.
   873 
   874 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   875 provide backward reasoning on locales predicates.  The methods are
   876 aware of interpretations and discharge corresponding goals.
   877 `intro_locales' is less aggressive then `unfold_locales' and does not
   878 unfold predicates to assumptions.
   879 
   880 * Isar/locales: the order in which locale fragments are accumulated
   881 has changed.  This enables to override declarations from fragments due
   882 to interpretations -- for example, unwanted simp rules.
   883 
   884 * Isar/locales: interpretation in theories and proof contexts has been
   885 extended.  One may now specify (and prove) equations, which are
   886 unfolded in interpreted theorems.  This is useful for replacing
   887 defined concepts (constants depending on locale parameters) by
   888 concepts already existing in the target context.  Example:
   889 
   890   interpretation partial_order ["op <= :: [int, int] => bool"]
   891     where "partial_order.less (op <=) (x::int) y = (x < y)"
   892 
   893 Typically, the constant `partial_order.less' is created by a
   894 definition specification element in the context of locale
   895 partial_order.
   896 
   897 * Method "induct": improved internal context management to support
   898 local fixes and defines on-the-fly. Thus explicit meta-level
   899 connectives !!  and ==> are rarely required anymore in inductive goals
   900 (using object-logic connectives for this purpose has been long
   901 obsolete anyway). Common proof patterns are explained in
   902 src/HOL/Induct/Common_Patterns.thy, see also
   903 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   904 examples.
   905 
   906 * Method "induct": improved handling of simultaneous goals. Instead of
   907 introducing object-level conjunction, the statement is now split into
   908 several conclusions, while the corresponding symbolic cases are nested
   909 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   910 see src/HOL/Induct/Common_Patterns.thy, for example.
   911 
   912 * Method "induct": mutual induction rules are now specified as a list
   913 of rule sharing the same induction cases. HOL packages usually provide
   914 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   915 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   916 mutual induction rules differently, i.e. like this:
   917 
   918   (induct rule: foo_bar.inducts)
   919   (induct set: foo bar)
   920   (induct pred: foo bar)
   921   (induct type: foo bar)
   922 
   923 The ML function ProjectRule.projections turns old-style rules into the
   924 new format.
   925 
   926 * Method "coinduct": dual of induction, see
   927 src/HOL/Library/Coinductive_List.thy for various examples.
   928 
   929 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   930 considered a legacy feature.
   931 
   932 * Attribute "symmetric" produces result with standardized schematic
   933 variables (index 0).  Potential INCOMPATIBILITY.
   934 
   935 * Simplifier: by default the simplifier trace only shows top level
   936 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   937 default. Thus there is less danger of being flooded by the trace. The
   938 trace indicates where parts have been suppressed.
   939   
   940 * Provers/classical: removed obsolete classical version of elim_format
   941 attribute; classical elim/dest rules are now treated uniformly when
   942 manipulating the claset.
   943 
   944 * Provers/classical: stricter checks to ensure that supplied intro,
   945 dest and elim rules are well-formed; dest and elim rules must have at
   946 least one premise.
   947 
   948 * Provers/classical: attributes dest/elim/intro take an optional
   949 weight argument for the rule (just as the Pure versions).  Weights are
   950 ignored by automated tools, but determine the search order of single
   951 rule steps.
   952 
   953 * Syntax: input syntax now supports dummy variable binding "%_. b",
   954 where the body does not mention the bound variable.  Note that dummy
   955 patterns implicitly depend on their context of bounds, which makes
   956 "{_. _}" match any set comprehension as expected.  Potential
   957 INCOMPATIBILITY -- parse translations need to cope with syntactic
   958 constant "_idtdummy" in the binding position.
   959 
   960 * Syntax: removed obsolete syntactic constant "_K" and its associated
   961 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   962 for example "A -> B" => "Pi A (%_. B)".
   963 
   964 * Pure: 'class_deps' command visualizes the subclass relation, using
   965 the graph browser tool.
   966 
   967 * Pure: 'print_theory' now suppresses certain internal declarations by
   968 default; use '!' option for full details.
   969 
   970 
   971 *** HOL ***
   972 
   973 * Method "metis" proves goals by applying the Metis general-purpose
   974 resolution prover (see also http://gilith.com/software/metis/).
   975 Examples are in the directory MetisExamples.  WARNING: the
   976 Isabelle/HOL-Metis integration does not yet work properly with
   977 multi-threading.
   978   
   979 * Command 'sledgehammer' invokes external automatic theorem provers as
   980 background processes.  It generates calls to the "metis" method if
   981 successful. These can be pasted into the proof.  Users do not have to
   982 wait for the automatic provers to return.  WARNING: does not really
   983 work with multi-threading.
   984 
   985 * New "auto_quickcheck" feature tests outermost goal statements for
   986 potential counter-examples.  Controlled by ML references
   987 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   988 5000 milliseconds).  Fails silently if statements is outside of
   989 executable fragment, or any other codgenerator problem occurs.
   990 
   991 * New constant "undefined" with axiom "undefined x = undefined".
   992 
   993 * Added class "HOL.eq", allowing for code generation with polymorphic
   994 equality.
   995 
   996 * Some renaming of class constants due to canonical name prefixing in
   997 the new 'class' package:
   998 
   999     HOL.abs ~> HOL.abs_class.abs
  1000     HOL.divide ~> HOL.divide_class.divide
  1001     0 ~> HOL.zero_class.zero
  1002     1 ~> HOL.one_class.one
  1003     op + ~> HOL.plus_class.plus
  1004     op - ~> HOL.minus_class.minus
  1005     uminus ~> HOL.minus_class.uminus
  1006     op * ~> HOL.times_class.times
  1007     op < ~> HOL.ord_class.less
  1008     op <= > HOL.ord_class.less_eq
  1009     Nat.power ~> Power.power_class.power
  1010     Nat.size ~> Nat.size_class.size
  1011     Numeral.number_of ~> Numeral.number_class.number_of
  1012     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1013     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1014     Orderings.min ~> Orderings.ord_class.min
  1015     Orderings.max ~> Orderings.ord_class.max
  1016     Divides.op div ~> Divides.div_class.div
  1017     Divides.op mod ~> Divides.div_class.mod
  1018     Divides.op dvd ~> Divides.div_class.dvd
  1019 
  1020 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1021 
  1022 a) User-defined constants using any of the names "plus", "minus",
  1023 "times", "less" or "less_eq". The standard syntax translations for
  1024 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1025 names.
  1026 
  1027 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1028 INCOMPATIBILITY: use more specific names.
  1029 
  1030 c) Permutative equations (e.g. "a + b = b + a")
  1031 Since the change of names also changes the order of terms, permutative
  1032 rewrite rules may get applied in a different order. Experience shows
  1033 that this is rarely the case (only two adaptions in the whole Isabelle
  1034 distribution).  INCOMPATIBILITY: rewrite proofs
  1035 
  1036 d) ML code directly refering to constant names
  1037 This in general only affects hand-written proof tactics, simprocs and
  1038 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1039 Consider using @{const_name} antiquotation.
  1040 
  1041 * New class "default" with associated constant "default".
  1042 
  1043 * Function "sgn" is now overloaded and available on int, real, complex
  1044 (and other numeric types), using class "sgn".  Two possible defs of
  1045 sgn are given as equational assumptions in the classes sgn_if and
  1046 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1047 INCOMPATIBILITY.
  1048 
  1049 * Locale "partial_order" now unified with class "order" (cf. theory
  1050 Orderings), added parameter "less".  INCOMPATIBILITY.
  1051 
  1052 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1053 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1054 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1055 
  1056 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1057 changed order of proof goals in instance proofs.
  1058 
  1059 * The transitivity reasoner for partial and linear orders is set up
  1060 for classes "order" and "linorder".  Instances of the reasoner are available
  1061 in all contexts importing or interpreting the corresponding locales.
  1062 Method "order" invokes the reasoner separately; the reasoner
  1063 is also integrated with the Simplifier as a solver.  Diagnostic
  1064 command 'print_orders' shows the available instances of the reasoner
  1065 in the current context.
  1066 
  1067 * Localized monotonicity predicate in theory "Orderings"; integrated
  1068 lemmas max_of_mono and min_of_mono with this predicate.
  1069 INCOMPATIBILITY.
  1070 
  1071 * Formulation of theorem "dense" changed slightly due to integration
  1072 with new class dense_linear_order.
  1073 
  1074 * Uniform lattice theory development in HOL.
  1075 
  1076     constants "meet" and "join" now named "inf" and "sup"
  1077     constant "Meet" now named "Inf"
  1078 
  1079     classes "meet_semilorder" and "join_semilorder" now named
  1080       "lower_semilattice" and "upper_semilattice"
  1081     class "lorder" now named "lattice"
  1082     class "comp_lat" now named "complete_lattice"
  1083 
  1084     Instantiation of lattice classes allows explicit definitions
  1085     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1086 
  1087   INCOMPATIBILITY.  Theorem renames:
  1088 
  1089     meet_left_le            ~> inf_le1
  1090     meet_right_le           ~> inf_le2
  1091     join_left_le            ~> sup_ge1
  1092     join_right_le           ~> sup_ge2
  1093     meet_join_le            ~> inf_sup_ord
  1094     le_meetI                ~> le_infI
  1095     join_leI                ~> le_supI
  1096     le_meet                 ~> le_inf_iff
  1097     le_join                 ~> ge_sup_conv
  1098     meet_idempotent         ~> inf_idem
  1099     join_idempotent         ~> sup_idem
  1100     meet_comm               ~> inf_commute
  1101     join_comm               ~> sup_commute
  1102     meet_leI1               ~> le_infI1
  1103     meet_leI2               ~> le_infI2
  1104     le_joinI1               ~> le_supI1
  1105     le_joinI2               ~> le_supI2
  1106     meet_assoc              ~> inf_assoc
  1107     join_assoc              ~> sup_assoc
  1108     meet_left_comm          ~> inf_left_commute
  1109     meet_left_idempotent    ~> inf_left_idem
  1110     join_left_comm          ~> sup_left_commute
  1111     join_left_idempotent    ~> sup_left_idem
  1112     meet_aci                ~> inf_aci
  1113     join_aci                ~> sup_aci
  1114     le_def_meet             ~> le_iff_inf
  1115     le_def_join             ~> le_iff_sup
  1116     join_absorp2            ~> sup_absorb2
  1117     join_absorp1            ~> sup_absorb1
  1118     meet_absorp1            ~> inf_absorb1
  1119     meet_absorp2            ~> inf_absorb2
  1120     meet_join_absorp        ~> inf_sup_absorb
  1121     join_meet_absorp        ~> sup_inf_absorb
  1122     distrib_join_le         ~> distrib_sup_le
  1123     distrib_meet_le         ~> distrib_inf_le
  1124 
  1125     add_meet_distrib_left   ~> add_inf_distrib_left
  1126     add_join_distrib_left   ~> add_sup_distrib_left
  1127     is_join_neg_meet        ~> is_join_neg_inf
  1128     is_meet_neg_join        ~> is_meet_neg_sup
  1129     add_meet_distrib_right  ~> add_inf_distrib_right
  1130     add_join_distrib_right  ~> add_sup_distrib_right
  1131     add_meet_join_distribs  ~> add_sup_inf_distribs
  1132     join_eq_neg_meet        ~> sup_eq_neg_inf
  1133     meet_eq_neg_join        ~> inf_eq_neg_sup
  1134     add_eq_meet_join        ~> add_eq_inf_sup
  1135     meet_0_imp_0            ~> inf_0_imp_0
  1136     join_0_imp_0            ~> sup_0_imp_0
  1137     meet_0_eq_0             ~> inf_0_eq_0
  1138     join_0_eq_0             ~> sup_0_eq_0
  1139     neg_meet_eq_join        ~> neg_inf_eq_sup
  1140     neg_join_eq_meet        ~> neg_sup_eq_inf
  1141     join_eq_if              ~> sup_eq_if
  1142 
  1143     mono_meet               ~> mono_inf
  1144     mono_join               ~> mono_sup
  1145     meet_bool_eq            ~> inf_bool_eq
  1146     join_bool_eq            ~> sup_bool_eq
  1147     meet_fun_eq             ~> inf_fun_eq
  1148     join_fun_eq             ~> sup_fun_eq
  1149     meet_set_eq             ~> inf_set_eq
  1150     join_set_eq             ~> sup_set_eq
  1151     meet1_iff               ~> inf1_iff
  1152     meet2_iff               ~> inf2_iff
  1153     meet1I                  ~> inf1I
  1154     meet2I                  ~> inf2I
  1155     meet1D1                 ~> inf1D1
  1156     meet2D1                 ~> inf2D1
  1157     meet1D2                 ~> inf1D2
  1158     meet2D2                 ~> inf2D2
  1159     meet1E                  ~> inf1E
  1160     meet2E                  ~> inf2E
  1161     join1_iff               ~> sup1_iff
  1162     join2_iff               ~> sup2_iff
  1163     join1I1                 ~> sup1I1
  1164     join2I1                 ~> sup2I1
  1165     join1I1                 ~> sup1I1
  1166     join2I2                 ~> sup1I2
  1167     join1CI                 ~> sup1CI
  1168     join2CI                 ~> sup2CI
  1169     join1E                  ~> sup1E
  1170     join2E                  ~> sup2E
  1171 
  1172     is_meet_Meet            ~> is_meet_Inf
  1173     Meet_bool_def           ~> Inf_bool_def
  1174     Meet_fun_def            ~> Inf_fun_def
  1175     Meet_greatest           ~> Inf_greatest
  1176     Meet_lower              ~> Inf_lower
  1177     Meet_set_def            ~> Inf_set_def
  1178 
  1179     Sup_def                 ~> Sup_Inf
  1180     Sup_bool_eq             ~> Sup_bool_def
  1181     Sup_fun_eq              ~> Sup_fun_def
  1182     Sup_set_eq              ~> Sup_set_def
  1183 
  1184     listsp_meetI            ~> listsp_infI
  1185     listsp_meet_eq          ~> listsp_inf_eq
  1186 
  1187     meet_min                ~> inf_min
  1188     join_max                ~> sup_max
  1189 
  1190 * Added syntactic class "size"; overloaded constant "size" now has
  1191 type "'a::size ==> bool"
  1192 
  1193 * Internal reorganisation of `size' of datatypes: size theorems
  1194 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1195 simplification rules by default!); theorems "prod.size" now named
  1196 "*.size".
  1197 
  1198 * Class "div" now inherits from class "times" rather than "type".
  1199 INCOMPATIBILITY.
  1200 
  1201 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1202 Linorder etc.  have disappeared; operations defined in terms of
  1203 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1204 
  1205 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1206 
  1207 * HOL-Word: New extensive library and type for generic, fixed size
  1208 machine words, with arithemtic, bit-wise, shifting and rotating
  1209 operations, reflection into int, nat, and bool lists, automation for
  1210 linear arithmetic (by automatic reflection into nat or int), including
  1211 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1212 arithmetic type classes, supporting automatic simplification of
  1213 numerals on all operations.
  1214 
  1215 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1216 
  1217 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1218 
  1219 * Code generator library theories:
  1220   - Code_Integer represents HOL integers by big integer literals in target
  1221     languages.
  1222   - Code_Char represents HOL characters by character literals in target
  1223     languages.
  1224   - Code_Char_chr like Code_Char, but also offers treatment of character
  1225     codes; includes Code_Integer.
  1226   - Executable_Set allows to generate code for finite sets using lists.
  1227   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1228     denominator).
  1229   - Executable_Real implements a subset of real numbers, namly those
  1230     representable by rational numbers.
  1231   - Efficient_Nat implements natural numbers by integers, which in general will
  1232     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1233     includes Code_Integer.
  1234   - Code_Index provides an additional datatype index which is mapped to
  1235     target-language built-in integers.
  1236   - Code_Message provides an additional datatype message_string which is isomorphic to
  1237     strings; messages are mapped to target-language strings.
  1238 
  1239 * New package for inductive predicates
  1240 
  1241   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1242 
  1243     inductive
  1244       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1245       for z_1 :: U_1 and ... and z_n :: U_m
  1246     where
  1247       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1248     | ...
  1249 
  1250   with full support for type-inference, rather than
  1251 
  1252     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1253 
  1254     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1255     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1256 
  1257     inductive "s z_1 ... z_m"
  1258     intros
  1259       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1260       ...
  1261 
  1262   For backward compatibility, there is a wrapper allowing inductive
  1263   sets to be defined with the new package via
  1264 
  1265     inductive_set
  1266       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1267       for z_1 :: U_1 and ... and z_n :: U_m
  1268     where
  1269       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1270     | ...
  1271 
  1272   or
  1273 
  1274     inductive_set
  1275       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1276       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1277       for z_1 :: U_1 and ... and z_n :: U_m
  1278     where
  1279       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1280     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1281     | ...
  1282 
  1283   if the additional syntax "p ..." is required.
  1284 
  1285   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1286   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1287 
  1288   INCOMPATIBILITIES:
  1289 
  1290   - Since declaration and definition of inductive sets or predicates
  1291     is no longer separated, abbreviations involving the newly
  1292     introduced sets or predicates must be specified together with the
  1293     introduction rules after the 'where' keyword (see above), rather
  1294     than before the actual inductive definition.
  1295 
  1296   - The variables in induction and elimination rules are now
  1297     quantified in the order of their occurrence in the introduction
  1298     rules, rather than in alphabetical order. Since this may break
  1299     some proofs, these proofs either have to be repaired, e.g. by
  1300     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1301     statements of the form
  1302 
  1303       case (rule_i a_i_1 ... a_i_{k_i})
  1304 
  1305     or the old order of quantification has to be restored by explicitly adding
  1306     meta-level quantifiers in the introduction rules, i.e.
  1307 
  1308       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1309 
  1310   - The format of the elimination rules is now
  1311 
  1312       p z_1 ... z_m x_1 ... x_n ==>
  1313         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1314         ==> ... ==> P
  1315 
  1316     for predicates and
  1317 
  1318       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1319         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1320         ==> ... ==> P
  1321 
  1322     for sets rather than
  1323 
  1324       x : s z_1 ... z_m ==>
  1325         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1326         ==> ... ==> P
  1327 
  1328     This may require terms in goals to be expanded to n-tuples
  1329     (e.g. using case_tac or simplification with the split_paired_all
  1330     rule) before the above elimination rule is applicable.
  1331 
  1332   - The elimination or case analysis rules for (mutually) inductive
  1333     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1334     list of rules "p_1_..._p_k.elims" is no longer available.
  1335 
  1336 * New package "function"/"fun" for general recursive functions,
  1337 supporting mutual and nested recursion, definitions in local contexts,
  1338 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1339 for small examples, and the separate tutorial on the function
  1340 package. The old recdef "package" is still available as before, but
  1341 users are encouraged to use the new package.
  1342 
  1343 * Method "lexicographic_order" automatically synthesizes termination
  1344 relations as lexicographic combinations of size measures. 
  1345 
  1346 * Case-expressions allow arbitrary constructor-patterns (including
  1347 "_") and take their order into account, like in functional
  1348 programming.  Internally, this is translated into nested
  1349 case-expressions; missing cases are added and mapped to the predefined
  1350 constant "undefined". In complicated cases printing may no longer show
  1351 the original input but the internal form. Lambda-abstractions allow
  1352 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1353 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1354 variable.
  1355 
  1356 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1357 is an abbreviation for "of_nat :: nat => int". The simplification
  1358 rules for "of_nat" have been changed to work like "int" did
  1359 previously.  Potential INCOMPATIBILITY:
  1360   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1361   - of_nat_diff and of_nat_mult are no longer default simp rules
  1362 
  1363 * Method "algebra" solves polynomial equations over (semi)rings using
  1364 Groebner bases. The (semi)ring structure is defined by locales and the
  1365 tool setup depends on that generic context. Installing the method for
  1366 a specific type involves instantiating the locale and possibly adding
  1367 declarations for computation on the coefficients.  The method is
  1368 already instantiated for natural numbers and for the axiomatic class
  1369 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1370 CALCULEMUS 2007 for the general principles underlying this
  1371 architecture of context-aware proof-tools.
  1372 
  1373 * Method "ferrack" implements quantifier elimination over
  1374 special-purpose dense linear orders using locales (analogous to
  1375 "algebra"). The method is already installed for class
  1376 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1377 rat, etc.
  1378 
  1379 * Former constant "List.op @" now named "List.append".  Use ML
  1380 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1381 circumvent possible incompatibilities when working on ML level.
  1382 
  1383 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1384 
  1385 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1386 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1387 
  1388 * New syntax for Haskell-like list comprehension (input only), eg.
  1389 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1390 
  1391 * The special syntax for function "filter" has changed from [x :
  1392 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1393 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1394 
  1395 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1396 defined on nat only, as an abbreviation for [a..<Suc b]
  1397 INCOMPATIBILITY.
  1398 
  1399 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1400 
  1401 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1402 
  1403 * New lemma collection field_simps (an extension of ring_simps) for
  1404 manipulating (in)equations involving division. Multiplies with all
  1405 denominators that can be proved to be non-zero (in equations) or
  1406 positive/negative (in inequations).
  1407 
  1408 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1409 have been improved and renamed to ring_simps, group_simps and
  1410 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1411 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1412 
  1413 * Theory Library/Commutative_Ring: switched from recdef to function
  1414 package; constants add, mul, pow now curried.  Infix syntax for
  1415 algebraic operations.
  1416 
  1417 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1418 INCOMPATIBILITY.
  1419 
  1420 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1421 INCOMPATIBILITY.
  1422 
  1423 * HOL/records: generalised field-update to take a function on the
  1424 field rather than the new value: r(|A := x|) is translated to A_update
  1425 (K x) r The K-combinator that is internally used is called K_record.
  1426 INCOMPATIBILITY: Usage of the plain update functions has to be
  1427 adapted.
  1428  
  1429 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1430 * x = 0, which are required for a semiring.  Richer structures do not
  1431 inherit from semiring_0 anymore, because this property is a theorem
  1432 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1433 there is more to prove, but this is mostly trivial.
  1434 
  1435 * Class "recpower" is generalized to arbitrary monoids, not just
  1436 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1437 commutativity or semiring properties additionally.
  1438 
  1439 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1440 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1441 better use 'abbreviation'.
  1442 
  1443 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1444 
  1445 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1446 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1447 significant changes for setting up numeral syntax for types:
  1448   - New constants Numeral.pred and Numeral.succ instead
  1449       of former Numeral.bin_pred and Numeral.bin_succ.
  1450   - Use integer operations instead of bin_add, bin_mult and so on.
  1451   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1452   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1453 
  1454 See src/HOL/Integ/IntArith.thy for an example setup.
  1455 
  1456 * Command 'normal_form' computes the normal form of a term that may
  1457 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1458 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1459 heavy-duty computations because the functions are compiled to ML
  1460 first.  Correspondingly, a method "normalization" is provided.  See
  1461 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1462 
  1463 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1464 25 like -->); output depends on the "iff" print_mode, the default is
  1465 "A = B" (with priority 50).
  1466 
  1467 * Relations less (<) and less_eq (<=) are also available on type bool.
  1468 Modified syntax to disallow nesting without explicit parentheses,
  1469 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1470 INCOMPATIBILITY.
  1471 
  1472 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1473 
  1474 * Relation composition operator "op O" now has precedence 75 and binds
  1475 stronger than union and intersection. INCOMPATIBILITY.
  1476 
  1477 * The old set interval syntax "{m..n(}" (and relatives) has been
  1478 removed.  Use "{m..<n}" (and relatives) instead.
  1479 
  1480 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1481 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1482 ``declare [[simproc del: neq]]''.
  1483 
  1484 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1485 True/False.
  1486 
  1487 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1488 
  1489 * Theorem setsum_mult renamed to setsum_right_distrib.
  1490 
  1491 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1492 ``rule'' method.
  1493 
  1494 * Reimplemented methods "sat" and "satx", with several improvements:
  1495 goals no longer need to be stated as "<prems> ==> False", equivalences
  1496 (i.e. "=" on type bool) are handled, variable names of the form
  1497 "lit_<n>" are no longer reserved, significant speedup.
  1498 
  1499 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1500 zChaff is still supported as well.
  1501 
  1502 * 'inductive' and 'datatype': provide projections of mutual rules,
  1503 bundled as foo_bar.inducts;
  1504 
  1505 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1506 Library.
  1507 
  1508 * Library: moved theory Accessible_Part to main HOL.
  1509 
  1510 * Library: added theory Coinductive_List of potentially infinite lists
  1511 as greatest fixed-point.
  1512 
  1513 * Library: added theory AssocList which implements (finite) maps as
  1514 association lists.
  1515 
  1516 * Method "evaluation" solves goals (i.e. a boolean expression)
  1517 efficiently by compiling it to ML.  The goal is "proved" (via an
  1518 oracle) if it evaluates to True.
  1519 
  1520 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1521 also when invoked by the simplifier.  This results in the Simplifier
  1522 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1523 Configuration option fast_arith_split_limit=0 recovers the old
  1524 behavior.
  1525 
  1526 * Support for hex (0x20) and binary (0b1001) numerals.
  1527 
  1528 * New method: reify eqs (t), where eqs are equations for an
  1529 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1530 parameter, computes a term s::'b and a list xs::'a list and proves the
  1531 theorem I xs s = t. This is also known as reification or quoting. The
  1532 resulting theorem is applied to the subgoal to substitute t with I xs
  1533 s.  If t is omitted, the subgoal itself is reified.
  1534 
  1535 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1536 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1537 where f is supposed to be a computable function (in the sense of code
  1538 generattion). The method uses reify to compute s and xs as above then
  1539 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1540 r and finally gets the theorem t = r, which is again applied to the
  1541 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1542 
  1543 * Reflection: Automatic reification now handels binding, an example is
  1544 available in src/HOL/ex/ReflectionEx.thy
  1545 
  1546 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1547 command 'statespace' that is similar to 'record', but introduces an
  1548 abstract specification based on the locale infrastructure instead of
  1549 HOL types.  This leads to extra flexibility in composing state spaces,
  1550 in particular multiple inheritance and renaming of components.
  1551 
  1552 
  1553 *** HOL-Complex ***
  1554 
  1555 * Hyperreal: Functions root and sqrt are now defined on negative real
  1556 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1557 Nonnegativity side conditions have been removed from many lemmas, so
  1558 that more subgoals may now be solved by simplification; potential
  1559 INCOMPATIBILITY.
  1560 
  1561 * Real: new type classes formalize real normed vector spaces and
  1562 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1563 and norm :: 'a => real.
  1564 
  1565 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1566 reals into other types. The overloaded constant Reals :: 'a set is now
  1567 defined as range of_real; potential INCOMPATIBILITY.
  1568 
  1569 * Real: proper support for ML code generation, including 'quickcheck'.
  1570 Reals are implemented as arbitrary precision rationals.
  1571 
  1572 * Hyperreal: Several constants that previously worked only for the
  1573 reals have been generalized, so they now work over arbitrary vector
  1574 spaces. Type annotations may need to be added in some cases; potential
  1575 INCOMPATIBILITY.
  1576 
  1577   Infinitesimal  :: ('a::real_normed_vector) star set
  1578   HFinite        :: ('a::real_normed_vector) star set
  1579   HInfinite      :: ('a::real_normed_vector) star set
  1580   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1581   monad          :: ('a::real_normed_vector) star => 'a star set
  1582   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1583   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1584   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1585   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1586   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1587   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1588   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1589   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1590   sgn            :: 'a::real_normed_vector => 'a
  1591   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1592 
  1593 * Complex: Some complex-specific constants are now abbreviations for
  1594 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1595 hnorm.  Other constants have been entirely removed in favor of the
  1596 polymorphic versions (INCOMPATIBILITY):
  1597 
  1598   approx        <-- capprox
  1599   HFinite       <-- CFinite
  1600   HInfinite     <-- CInfinite
  1601   Infinitesimal <-- CInfinitesimal
  1602   monad         <-- cmonad
  1603   galaxy        <-- cgalaxy
  1604   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1605   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1606   (ns)deriv     <-- (ns)cderiv
  1607 
  1608 
  1609 *** HOL-Algebra ***
  1610 
  1611 * Formalisation of ideals and the quotient construction over rings.
  1612 
  1613 * Order and lattice theory no longer based on records.
  1614 INCOMPATIBILITY.
  1615 
  1616 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1617 greatest_closed.  INCOMPATIBILITY.
  1618 
  1619 * Method algebra is now set up via an attribute.  For examples see
  1620 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1621 of algebraic structures.
  1622 
  1623 * Renamed theory CRing to Ring.
  1624 
  1625 
  1626 *** HOL-Nominal ***
  1627 
  1628 * Substantial, yet incomplete support for nominal datatypes (binding
  1629 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1630 src/HOL/Nominal/Examples.  Prospective users should consult
  1631 http://isabelle.in.tum.de/nominal/
  1632 
  1633 
  1634 *** ML ***
  1635 
  1636 * ML basics: just one true type int, which coincides with IntInf.int
  1637 (even on SML/NJ).
  1638 
  1639 * ML within Isar: antiquotations allow to embed statically-checked
  1640 formal entities in the source, referring to the context available at
  1641 compile-time.  For example:
  1642 
  1643 ML {* @{sort "{zero,one}"} *}
  1644 ML {* @{typ "'a => 'b"} *}
  1645 ML {* @{term "%x. x"} *}
  1646 ML {* @{prop "x == y"} *}
  1647 ML {* @{ctyp "'a => 'b"} *}
  1648 ML {* @{cterm "%x. x"} *}
  1649 ML {* @{cprop "x == y"} *}
  1650 ML {* @{thm asm_rl} *}
  1651 ML {* @{thms asm_rl} *}
  1652 ML {* @{type_name c} *}
  1653 ML {* @{type_syntax c} *}
  1654 ML {* @{const_name c} *}
  1655 ML {* @{const_syntax c} *}
  1656 ML {* @{context} *}
  1657 ML {* @{theory} *}
  1658 ML {* @{theory Pure} *}
  1659 ML {* @{theory_ref} *}
  1660 ML {* @{theory_ref Pure} *}
  1661 ML {* @{simpset} *}
  1662 ML {* @{claset} *}
  1663 ML {* @{clasimpset} *}
  1664 
  1665 The same works for sources being ``used'' within an Isar context.
  1666 
  1667 * ML in Isar: improved error reporting; extra verbosity with
  1668 ML_Context.trace enabled.
  1669 
  1670 * Pure/General/table.ML: the join operations now works via exceptions
  1671 DUP/SAME instead of type option. This is simpler in simple cases, and
  1672 admits slightly more efficient complex applications.
  1673 
  1674 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1675 use Context.generic instead of just theory.
  1676 
  1677 * Pure: datatype Context.generic joins theory/Proof.context and
  1678 provides some facilities for code that works in either kind of
  1679 context, notably GenericDataFun for uniform theory and proof data.
  1680 
  1681 * Pure: simplified internal attribute type, which is now always
  1682 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1683 local (Proof.context) attributes have been discontinued, while
  1684 minimizing code duplication. Thm.rule_attribute and
  1685 Thm.declaration_attribute build canonical attributes; see also structure
  1686 Context for further operations on Context.generic, notably
  1687 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1688 declarations and definitions.
  1689 
  1690 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1691 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1692 init only required for impure data. INCOMPATIBILITY: empty really need
  1693 to be empty (no dependencies on theory content!)
  1694 
  1695 * Pure/kernel: consts certification ignores sort constraints given in
  1696 signature declarations. (This information is not relevant to the
  1697 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1698 potential INCOMPATIBILITY.
  1699 
  1700 * Pure: axiomatic type classes are now purely definitional, with
  1701 explicit proofs of class axioms and super class relations performed
  1702 internally. See Pure/axclass.ML for the main internal interfaces --
  1703 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1704 AxClass.axiomatize_class/classrel/arity supersede
  1705 Sign.add_classes/classrel/arities.
  1706 
  1707 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1708 global/local versions on theory vs. Proof.context have been
  1709 discontinued; Attrib.syntax and Method.syntax have been adapted
  1710 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1711 attributes, methods, etc.
  1712 
  1713 * Pure: several functions of signature "... -> theory -> theory * ..."
  1714 have been reoriented to "... -> theory -> ... * theory" in order to
  1715 allow natural usage in combination with the ||>, ||>>, |-> and
  1716 fold_map combinators.
  1717 
  1718 * Pure: official theorem names (closed derivations) and additional
  1719 comments (tags) are now strictly separate.  Name hints -- which are
  1720 maintained as tags -- may be attached any time without affecting the
  1721 derivation.
  1722 
  1723 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1724 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1725 achieve the old behaviour.
  1726 
  1727 * Pure: the "Goal" constant is now called "prop", supporting a
  1728 slightly more general idea of ``protecting'' meta-level rule
  1729 statements.
  1730 
  1731 * Pure: Logic.(un)varify only works in a global context, which is now
  1732 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1733 Logic.legacy_(un)varify as temporary workaround.
  1734 
  1735 * Pure: structure Name provides scalable operations for generating
  1736 internal variable names, notably Name.variants etc.  This replaces
  1737 some popular functions from term.ML:
  1738 
  1739   Term.variant		->  Name.variant
  1740   Term.variantlist	->  Name.variant_list
  1741   Term.invent_names	->  Name.invent_list
  1742 
  1743 Note that low-level renaming rarely occurs in new code -- operations
  1744 from structure Variable are used instead (see below).
  1745 
  1746 * Pure: structure Variable provides fundamental operations for proper
  1747 treatment of fixed/schematic variables in a context.  For example,
  1748 Variable.import introduces fixes for schematics of given facts and
  1749 Variable.export reverses the effect (up to renaming) -- this replaces
  1750 various freeze_thaw operations.
  1751 
  1752 * Pure: structure Goal provides simple interfaces for
  1753 init/conclude/finish and tactical prove operations (replacing former
  1754 Tactic.prove).  Goal.prove is the canonical way to prove results
  1755 within a given context; Goal.prove_global is a degraded version for
  1756 theory level goals, including a global Drule.standard.  Note that
  1757 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1758 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1759 in a locale context).
  1760 
  1761 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1762 and type checking (Syntax.check_term etc.), with common combinations
  1763 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1764 which are considered legacy and await removal.
  1765 
  1766 * Pure/Syntax: generic interfaces for type unchecking
  1767 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1768 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1769 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1770 available for convenience, but refer to the very same operations using
  1771 a mere theory instead of a full context.
  1772 
  1773 * Isar: simplified treatment of user-level errors, using exception
  1774 ERROR of string uniformly.  Function error now merely raises ERROR,
  1775 without any side effect on output channels.  The Isar toplevel takes
  1776 care of proper display of ERROR exceptions.  ML code may use plain
  1777 handle/can/try; cat_error may be used to concatenate errors like this:
  1778 
  1779   ... handle ERROR msg => cat_error msg "..."
  1780 
  1781 Toplevel ML code (run directly or through the Isar toplevel) may be
  1782 embedded into the Isar toplevel with exception display/debug like
  1783 this:
  1784 
  1785   Isar.toplevel (fn () => ...)
  1786 
  1787 INCOMPATIBILITY, removed special transform_error facilities, removed
  1788 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1789 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1790 -- use plain ERROR instead.
  1791 
  1792 * Isar: theory setup now has type (theory -> theory), instead of a
  1793 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1794 
  1795 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1796 ProofContext.debug/verbose flags.
  1797 
  1798 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1799 theory before entering a proof state.  Transactions now always see a
  1800 quasi-functional intermediate checkpoint, both in interactive and
  1801 batch mode.
  1802 
  1803 * Isar: simplified interfaces for outer syntax.  Renamed
  1804 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1805 OuterSyntax.add_parsers -- this functionality is now included in
  1806 OuterSyntax.command etc.  INCOMPATIBILITY.
  1807 
  1808 * Simplifier: the simpset of a running simplification process now
  1809 contains a proof context (cf. Simplifier.the_context), which is the
  1810 very context that the initial simpset has been retrieved from (by
  1811 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1812 (solver, looper etc.) may depend on arbitrary proof data.
  1813 
  1814 * Simplifier.inherit_context inherits the proof context (plus the
  1815 local bounds) of the current simplification process; any simproc
  1816 etc. that calls the Simplifier recursively should do this!  Removed
  1817 former Simplifier.inherit_bounds, which is already included here --
  1818 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1819 specify an explicit context using Simplifier.context/theory_context.
  1820 
  1821 * Simplifier/Classical Reasoner: more abstract interfaces
  1822 change_simpset/claset for modifying the simpset/claset reference of a
  1823 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1824 INCOMPATIBILITY.
  1825 
  1826 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1827 "Trueprop" etc.
  1828 
  1829 
  1830 *** System ***
  1831 
  1832 * settings: the default heap location within ISABELLE_HOME_USER now
  1833 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  1834 Isabelle installations.
  1835 
  1836 * isabelle-process: option -S (secure mode) disables some critical
  1837 operations, notably runtime compilation and evaluation of ML source
  1838 code.
  1839 
  1840 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1841 
  1842 * Support for parallel execution, using native multicore support of
  1843 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1844 independent theories, according to the given theory header
  1845 specifications. The maximum number of worker threads is specified via
  1846 usedir option -M or the "max-threads" setting in Proof General. A
  1847 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1848 to 6 on a 8-core machine.  User-code needs to observe certain
  1849 guidelines for thread-safe programming, see appendix A in the Isar
  1850 Implementation manual.
  1851 
  1852 
  1853 
  1854 New in Isabelle2005 (October 2005)
  1855 ----------------------------------
  1856 
  1857 *** General ***
  1858 
  1859 * Theory headers: the new header syntax for Isar theories is
  1860 
  1861   theory <name>
  1862   imports <theory1> ... <theoryN>
  1863   uses <file1> ... <fileM>
  1864   begin
  1865 
  1866 where the 'uses' part is optional.  The previous syntax
  1867 
  1868   theory <name> = <theory1> + ... + <theoryN>:
  1869 
  1870 will disappear in the next release.  Use isatool fixheaders to convert
  1871 existing theory files.  Note that there is no change in ancient
  1872 non-Isar theories now, but these will disappear soon.
  1873 
  1874 * Theory loader: parent theories can now also be referred to via
  1875 relative and absolute paths.
  1876 
  1877 * Command 'find_theorems' searches for a list of criteria instead of a
  1878 list of constants. Known criteria are: intro, elim, dest, name:string,
  1879 simp:term, and any term. Criteria can be preceded by '-' to select
  1880 theorems that do not match. Intro, elim, dest select theorems that
  1881 match the current goal, name:s selects theorems whose fully qualified
  1882 name contain s, and simp:term selects all simplification rules whose
  1883 lhs match term.  Any other term is interpreted as pattern and selects
  1884 all theorems matching the pattern. Available in ProofGeneral under
  1885 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1886 
  1887   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1888 
  1889 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1890 matching the current goal as introduction rule and not having "HOL."
  1891 in their name (i.e. not being defined in theory HOL).
  1892 
  1893 * Command 'thms_containing' has been discontinued in favour of
  1894 'find_theorems'; INCOMPATIBILITY.
  1895 
  1896 * Communication with Proof General is now 8bit clean, which means that
  1897 Unicode text in UTF-8 encoding may be used within theory texts (both
  1898 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1899 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1900 
  1901   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1902   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1903 
  1904 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1905 Classical Reasoner.  Typical big applications run around 2 times
  1906 faster.
  1907 
  1908 
  1909 *** Document preparation ***
  1910 
  1911 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1912 of raw sources.  Only those symbols that do not require additional
  1913 LaTeX packages (depending on comments in isabellesym.sty) are
  1914 displayed properly, everything else is left verbatim.  isatool display
  1915 and isatool print are used as front ends (these are subject to the
  1916 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1917 
  1918 * Command tags control specific markup of certain regions of text,
  1919 notably folding and hiding.  Predefined tags include "theory" (for
  1920 theory begin and end), "proof" for proof commands, and "ML" for
  1921 commands involving ML code; the additional tags "visible" and
  1922 "invisible" are unused by default.  Users may give explicit tag
  1923 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1924 interpretation of tags is determined by the LaTeX job during document
  1925 preparation: see option -V of isatool usedir, or options -n and -t of
  1926 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1927 \isadroptag.
  1928 
  1929 Several document versions may be produced at the same time via isatool
  1930 usedir (the generated index.html will link all of them).  Typical
  1931 specifications include ''-V document=theory,proof,ML'' to present
  1932 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1933 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1934 these parts without any formal replacement text.  The Isabelle site
  1935 default settings produce ''document'' and ''outline'' versions as
  1936 specified above.
  1937 
  1938 * Several new antiquotations:
  1939 
  1940   @{term_type term} prints a term with its type annotated;
  1941 
  1942   @{typeof term} prints the type of a term;
  1943 
  1944   @{const const} is the same as @{term const}, but checks that the
  1945   argument is a known logical constant;
  1946 
  1947   @{term_style style term} and @{thm_style style thm} print a term or
  1948   theorem applying a "style" to it
  1949 
  1950   @{ML text}
  1951 
  1952 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1953 definitions, equations, inequations etc., 'concl' printing only the
  1954 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1955 to print the specified premise.  TermStyle.add_style provides an ML
  1956 interface for introducing further styles.  See also the "LaTeX Sugar"
  1957 document practical applications.  The ML antiquotation prints
  1958 type-checked ML expressions verbatim.
  1959 
  1960 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1961 and 'text' support optional locale specification '(in loc)', which
  1962 specifies the default context for interpreting antiquotations.  For
  1963 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1964 
  1965 * Option 'locale=NAME' of antiquotations specifies an alternative
  1966 context interpreting the subsequent argument.  For example: @{thm
  1967 [locale=lattice] inf_assoc}.
  1968 
  1969 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1970 a proof context.
  1971 
  1972 * Proper output of antiquotations for theory commands involving a
  1973 proof context (such as 'locale' or 'theorem (in loc) ...').
  1974 
  1975 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1976 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1977 
  1978 * isatool usedir: new option -C (default true) controls whether option
  1979 -D should include a copy of the original document directory; -C false
  1980 prevents unwanted effects such as copying of administrative CVS data.
  1981 
  1982 
  1983 *** Pure ***
  1984 
  1985 * Considerably improved version of 'constdefs' command.  Now performs
  1986 automatic type-inference of declared constants; additional support for
  1987 local structure declarations (cf. locales and HOL records), see also
  1988 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1989 sequential dependencies of definitions within a single 'constdefs'
  1990 section; moreover, the declared name needs to be an identifier.  If
  1991 all fails, consider to fall back on 'consts' and 'defs' separately.
  1992 
  1993 * Improved indexed syntax and implicit structures.  First of all,
  1994 indexed syntax provides a notational device for subscripted
  1995 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1996 expressions.  Secondly, in a local context with structure
  1997 declarations, number indexes \<^sub>n or the empty index (default
  1998 number 1) refer to a certain fixed variable implicitly; option
  1999 show_structs controls printing of implicit structures.  Typical
  2000 applications of these concepts involve record types and locales.
  2001 
  2002 * New command 'no_syntax' removes grammar declarations (and
  2003 translations) resulting from the given syntax specification, which is
  2004 interpreted in the same manner as for the 'syntax' command.
  2005 
  2006 * 'Advanced' translation functions (parse_translation etc.) may depend
  2007 on the signature of the theory context being presently used for
  2008 parsing/printing, see also isar-ref manual.
  2009 
  2010 * Improved 'oracle' command provides a type-safe interface to turn an
  2011 ML expression of type theory -> T -> term into a primitive rule of
  2012 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2013 is already included here); see also FOL/ex/IffExample.thy;
  2014 INCOMPATIBILITY.
  2015 
  2016 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2017 before); "cI" is no longer bound, use "c.intro" instead.
  2018 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2019 axclasses vs. locales.
  2020 
  2021 * Improved internal renaming of symbolic identifiers -- attach primes
  2022 instead of base 26 numbers.
  2023 
  2024 * New flag show_question_marks controls printing of leading question
  2025 marks in schematic variable names.
  2026 
  2027 * In schematic variable names, *any* symbol following \<^isub> or
  2028 \<^isup> is now treated as part of the base name.  For example, the
  2029 following works without printing of awkward ".0" indexes:
  2030 
  2031   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2032     by simp
  2033 
  2034 * Inner syntax includes (*(*nested*) comments*).
  2035 
  2036 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2037 annotations as "(00...)".
  2038 
  2039 * Clear separation of logical types and nonterminals, where the latter
  2040 may only occur in 'syntax' specifications or type abbreviations.
  2041 Before that distinction was only partially implemented via type class
  2042 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2043 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2044 exotic syntax specifications may require further adaption
  2045 (e.g. Cube/Cube.thy).
  2046 
  2047 * Removed obsolete type class "logic", use the top sort {} instead.
  2048 Note that non-logical types should be declared as 'nonterminals'
  2049 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2050 specifications.
  2051 
  2052 * Attributes 'induct' and 'cases': type or set names may now be
  2053 locally fixed variables as well.
  2054 
  2055 * Simplifier: can now control the depth to which conditional rewriting
  2056 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2057 Limit.
  2058 
  2059 * Simplifier: simplification procedures may now take the current
  2060 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2061 interface), which is very useful for calling the Simplifier
  2062 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2063 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2064 low-level mk_simproc no longer applies Logic.varify internally, to
  2065 allow for use in a context of fixed variables.
  2066 
  2067 * thin_tac now works even if the assumption being deleted contains !!
  2068 or ==>.  More generally, erule now works even if the major premise of
  2069 the elimination rule contains !! or ==>.
  2070 
  2071 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2072 
  2073 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2074 from Pure, which contains all common declarations already.  Both
  2075 theories are defined via plain Isabelle/Isar .thy files.
  2076 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2077 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2078 use isatool fixcpure to adapt your theory and ML sources.
  2079 
  2080 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2081 selections of theorems in named facts via index ranges.
  2082 
  2083 * 'print_theorems': in theory mode, really print the difference
  2084 wrt. the last state (works for interactive theory development only),
  2085 in proof mode print all local facts (cf. 'print_facts');
  2086 
  2087 * 'hide': option '(open)' hides only base names.
  2088 
  2089 * More efficient treatment of intermediate checkpoints in interactive
  2090 theory development.
  2091 
  2092 * Code generator is now invoked via code_module (incremental code
  2093 generation) and code_library (modular code generation, ML structures
  2094 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2095 must be quoted when used as identifiers.
  2096 
  2097 * New 'value' command for reading, evaluating and printing terms using
  2098 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2099 quoted when used as identifier.
  2100 
  2101 
  2102 *** Locales ***
  2103 
  2104 * New commands for the interpretation of locale expressions in
  2105 theories (1), locales (2) and proof contexts (3).  These generate
  2106 proof obligations from the expression specification.  After the
  2107 obligations have been discharged, theorems of the expression are added
  2108 to the theory, target locale or proof context.  The synopsis of the
  2109 commands is a follows:
  2110 
  2111   (1) interpretation expr inst
  2112   (2) interpretation target < expr
  2113   (3) interpret expr inst
  2114 
  2115 Interpretation in theories and proof contexts require a parameter
  2116 instantiation of terms from the current context.  This is applied to
  2117 specifications and theorems of the interpreted expression.
  2118 Interpretation in locales only permits parameter renaming through the
  2119 locale expression.  Interpretation is smart in that interpretations
  2120 that are active already do not occur in proof obligations, neither are
  2121 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2122 inspect active interpretations of a particular locale.  For details,
  2123 see the Isar Reference manual.  Examples can be found in
  2124 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2125 
  2126 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2127 'interpret' instead.
  2128 
  2129 * New context element 'constrains' for adding type constraints to
  2130 parameters.
  2131 
  2132 * Context expressions: renaming of parameters with syntax
  2133 redeclaration.
  2134 
  2135 * Locale declaration: 'includes' disallowed.
  2136 
  2137 * Proper static binding of attribute syntax -- i.e. types / terms /
  2138 facts mentioned as arguments are always those of the locale definition
  2139 context, independently of the context of later invocations.  Moreover,
  2140 locale operations (renaming and type / term instantiation) are applied
  2141 to attribute arguments as expected.
  2142 
  2143 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2144 actual attributes; rare situations may require Attrib.attribute to
  2145 embed those attributes into Attrib.src that lack concrete syntax.
  2146 Attribute implementations need to cooperate properly with the static
  2147 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2148 Attrib.XXX_thm etc. already do the right thing without further
  2149 intervention.  Only unusual applications -- such as "where" or "of"
  2150 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2151 on the context and the facts involved -- may have to assign parsed
  2152 values to argument tokens explicitly.
  2153 
  2154 * Changed parameter management in theorem generation for long goal
  2155 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2156 theorem statement in rare situations.
  2157 
  2158 * Locale inspection command 'print_locale' omits notes elements.  Use
  2159 'print_locale!' to have them included in the output.
  2160 
  2161 
  2162 *** Provers ***
  2163 
  2164 * Provers/hypsubst.ML: improved version of the subst method, for
  2165 single-step rewriting: it now works in bound variable contexts. New is
  2166 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2167 rewrite a different subterm than the original subst method, which is
  2168 still available as 'simplesubst'.
  2169 
  2170 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2171 and quasi orders.
  2172 
  2173 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2174 reflexive-transitive closure of relations.
  2175 
  2176 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2177 limit (previously hard-coded with a value of 20) user-definable.
  2178 
  2179 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2180 is peformed already.  Object-logics merely need to finish their
  2181 initial simpset configuration as before.  INCOMPATIBILITY.
  2182 
  2183 
  2184 *** HOL ***
  2185 
  2186 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2187 
  2188   syntax (epsilon)
  2189     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2190 
  2191 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2192 and x-symbol; use option '-m epsilon' to get it actually printed.
  2193 Moreover, the mathematically important symbolic identifier \<epsilon>
  2194 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2195 
  2196 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2197 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2198 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2199 support corresponding Isar calculations.
  2200 
  2201 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2202 instead of ":".
  2203 
  2204 * theory SetInterval: changed the syntax for open intervals:
  2205 
  2206   Old       New
  2207   {..n(}    {..<n}
  2208   {)n..}    {n<..}
  2209   {m..n(}   {m..<n}
  2210   {)m..n}   {m<..n}
  2211   {)m..n(}  {m<..<n}
  2212 
  2213 The old syntax is still supported but will disappear in the next
  2214 release.  For conversion use the following Emacs search and replace
  2215 patterns (these are not perfect but work quite well):
  2216 
  2217   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2218   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2219 
  2220 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2221 equalities in commutative rings; method 'algebra' provides a generic
  2222 interface.
  2223 
  2224 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2225 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2226 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2227 be a tuple pattern.
  2228 
  2229 Some new syntax forms are available:
  2230 
  2231   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2232   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2233   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2234   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2235 
  2236 The latter form "\<Sum>x < k. e" used to be based on a separate
  2237 function "Summation", which has been discontinued.
  2238 
  2239 * theory Finite_Set: in structured induction proofs, the insert case
  2240 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2241 (insert F x)'.
  2242 
  2243 * The 'refute' command has been extended to support a much larger
  2244 fragment of HOL, including axiomatic type classes, constdefs and
  2245 typedefs, inductive datatypes and recursion.
  2246 
  2247 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2248 Requires zChaff with proof generation to be installed.  See
  2249 HOL/ex/SAT_Examples.thy for examples.
  2250 
  2251 * Datatype induction via method 'induct' now preserves the name of the
  2252 induction variable. For example, when proving P(xs::'a list) by
  2253 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2254 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2255 in unstructured proof scripts.
  2256 
  2257 * Reworked implementation of records.  Improved scalability for
  2258 records with many fields, avoiding performance problems for type
  2259 inference. Records are no longer composed of nested field types, but
  2260 of nested extension types. Therefore the record type only grows linear
  2261 in the number of extensions and not in the number of fields.  The
  2262 top-level (users) view on records is preserved.  Potential
  2263 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2264 old record representation. The type generated for a record is called
  2265 <record_name>_ext_type.
  2266 
  2267 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2268 proofs triggered by a record definition or a simproc (if
  2269 quick_and_dirty is enabled).  Definitions of large records can take
  2270 quite long.
  2271 
  2272 New simproc record_upd_simproc for simplification of multiple record
  2273 updates enabled by default.  Moreover, trivial updates are also
  2274 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2275 occasionally, since simplification is more powerful by default.
  2276 
  2277 * typedef: proper support for polymorphic sets, which contain extra
  2278 type-variables in the term.
  2279 
  2280 * Simplifier: automatically reasons about transitivity chains
  2281 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2282 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2283 old proofs break occasionally as simplification may now solve more
  2284 goals than previously.
  2285 
  2286 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2287 present.  Works for all partial orders (class "order"), in particular
  2288 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2289 just like y <= x.
  2290 
  2291 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2292 bound variable or a constant then the let is unfolded.  Otherwise
  2293 first a is simplified to b, and then f b is simplified to g. If
  2294 possible we abstract b from g arriving at "let x = b in h x",
  2295 otherwise we unfold the let and arrive at g.  The simproc can be
  2296 enabled/disabled by the reference use_let_simproc.  Potential
  2297 INCOMPATIBILITY since simplification is more powerful by default.
  2298 
  2299 * Classical reasoning: the meson method now accepts theorems as arguments.
  2300 
  2301 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2302 jobs to provide advice on the provability of subgoals.
  2303 
  2304 * Theory OrderedGroup and Ring_and_Field: various additions and
  2305 improvements to faciliate calculations involving equalities and
  2306 inequalities.
  2307 
  2308 The following theorems have been eliminated or modified
  2309 (INCOMPATIBILITY):
  2310 
  2311   abs_eq             now named abs_of_nonneg
  2312   abs_of_ge_0        now named abs_of_nonneg
  2313   abs_minus_eq       now named abs_of_nonpos
  2314   imp_abs_id         now named abs_of_nonneg
  2315   imp_abs_neg_id     now named abs_of_nonpos
  2316   mult_pos           now named mult_pos_pos
  2317   mult_pos_le        now named mult_nonneg_nonneg
  2318   mult_pos_neg_le    now named mult_nonneg_nonpos
  2319   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2320   mult_neg           now named mult_neg_neg
  2321   mult_neg_le        now named mult_nonpos_nonpos
  2322 
  2323 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2324      
  2325      zero_le_square
  2326      not_square_less_zero 
  2327 
  2328   The following lemmas have been deleted from Real/RealPow:
  2329   
  2330      realpow_zero_zero
  2331      realpow_two
  2332      realpow_less
  2333      zero_le_power
  2334      realpow_two_le
  2335      abs_realpow_two
  2336      realpow_two_abs     
  2337 
  2338 * Theory Parity: added rules for simplifying exponents.
  2339 
  2340 * Theory List:
  2341 
  2342 The following theorems have been eliminated or modified
  2343 (INCOMPATIBILITY):
  2344 
  2345   list_all_Nil       now named list_all.simps(1)
  2346   list_all_Cons      now named list_all.simps(2)
  2347   list_all_conv      now named list_all_iff
  2348   set_mem_eq         now named mem_iff
  2349 
  2350 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2351 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2352 
  2353 
  2354 *** HOL-Complex ***
  2355 
  2356 * Theory RealDef: better support for embedding natural numbers and
  2357 integers in the reals.
  2358 
  2359 The following theorems have been eliminated or modified
  2360 (INCOMPATIBILITY):
  2361 
  2362   exp_ge_add_one_self  now requires no hypotheses
  2363   real_of_int_add      reversed direction of equality (use [symmetric])
  2364   real_of_int_minus    reversed direction of equality (use [symmetric])
  2365   real_of_int_diff     reversed direction of equality (use [symmetric])
  2366   real_of_int_mult     reversed direction of equality (use [symmetric])
  2367 
  2368 * Theory RComplete: expanded support for floor and ceiling functions.
  2369 
  2370 * Theory Ln is new, with properties of the natural logarithm
  2371 
  2372 * Hyperreal: There is a new type constructor "star" for making
  2373 nonstandard types.  The old type names are now type synonyms:
  2374 
  2375   hypreal = real star
  2376   hypnat = nat star
  2377   hcomplex = complex star
  2378 
  2379 * Hyperreal: Many groups of similarly-defined constants have been
  2380 replaced by polymorphic versions (INCOMPATIBILITY):
  2381 
  2382   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2383 
  2384   starset      <-- starsetNat, starsetC
  2385   *s*          <-- *sNat*, *sc*
  2386   starset_n    <-- starsetNat_n, starsetC_n
  2387   *sn*         <-- *sNatn*, *scn*
  2388   InternalSets <-- InternalNatSets, InternalCSets
  2389 
  2390   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2391   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2392   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2393   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2394   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2395 
  2396 * Hyperreal: Many type-specific theorems have been removed in favor of
  2397 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2398 
  2399   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2400   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2401   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2402   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2403   right_minus <-- hypreal_add_minus
  2404   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2405   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2406   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2407   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2408   mult_1_right <-- hcomplex_mult_one_right
  2409   mult_zero_left <-- hcomplex_mult_zero_left
  2410   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2411   right_distrib <-- hypnat_add_mult_distrib2
  2412   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2413   right_inverse <-- hypreal_mult_inverse
  2414   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2415   order_refl <-- {hypreal,hypnat}_le_refl
  2416   order_trans <-- {hypreal,hypnat}_le_trans
  2417   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2418   order_less_le <-- {hypreal,hypnat}_less_le
  2419   linorder_linear <-- {hypreal,hypnat}_le_linear
  2420   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2421   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2422   add_nonneg_nonneg <-- hypreal_le_add_order
  2423 
  2424 * Hyperreal: Separate theorems having to do with type-specific
  2425 versions of constants have been merged into theorems that apply to the
  2426 new polymorphic constants (INCOMPATIBILITY):
  2427 
  2428   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2429   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2430   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2431   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2432   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2433   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2434   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2435   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2436   STAR_diff <-- {STAR,STARC}_diff
  2437   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2438     STARC_hcomplex_of_complex}_image_subset
  2439   starset_n_Un <-- starset{Nat,C}_n_Un
  2440   starset_n_Int <-- starset{Nat,C}_n_Int
  2441   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2442   starset_n_diff <-- starset{Nat,C}_n_diff
  2443   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2444   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2445   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2446   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2447   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2448   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2449   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2450   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2451   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2452   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2453   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2454   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2455   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2456   starfun_diff <-- starfun{C,RC,CR}_diff
  2457   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2458   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2459   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2460   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2461   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2462   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2463   starfun_Id <-- starfunC_Id
  2464   starfun_approx <-- starfun{Nat,CR}_approx
  2465   starfun_capprox <-- starfun{C,RC}_capprox
  2466   starfun_abs <-- starfunNat_rabs
  2467   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2468   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2469   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2470   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2471   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2472   starfun_add_approx <-- starfunCR_add_approx
  2473   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2474   starfun_divide <-- starfun{C,CR,RC}_divide
  2475   starfun_n <-- starfun{Nat,C}_n
  2476   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2477   starfun_n_add <-- starfun{Nat,C}_n_add
  2478   starfun_n_add_minus <-- starfunNat_n_add_minus
  2479   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2480   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2481   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2482 
  2483   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2484   star_n_minus <-- {hypreal,hcomplex}_minus
  2485   star_n_diff <-- {hypreal,hcomplex}_diff
  2486   star_n_mult <-- {hypreal,hcomplex}_mult
  2487   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2488   star_n_le <-- {hypreal,hypnat}_le
  2489   star_n_less <-- {hypreal,hypnat}_less
  2490   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2491   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2492   star_n_abs <-- hypreal_hrabs
  2493   star_n_divide <-- hcomplex_divide
  2494 
  2495   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2496   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2497   star_of_diff <-- hypreal_of_real_diff
  2498   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2499   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2500   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2501   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2502   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2503   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2504   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2505   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2506   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2507   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2508   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2509   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2510   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2511   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2512   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2513   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2514   star_of_power <-- hypreal_of_real_power
  2515   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2516 
  2517 * Hyperreal: new method "transfer" that implements the transfer
  2518 principle of nonstandard analysis. With a subgoal that mentions
  2519 nonstandard types like "'a star", the command "apply transfer"
  2520 replaces it with an equivalent one that mentions only standard types.
  2521 To be successful, all free variables must have standard types; non-
  2522 standard variables must have explicit universal quantifiers.
  2523 
  2524 * Hyperreal: A theory of Taylor series.
  2525 
  2526 
  2527 *** HOLCF ***
  2528 
  2529 * Discontinued special version of 'constdefs' (which used to support
  2530 continuous functions) in favor of the general Pure one with full
  2531 type-inference.
  2532 
  2533 * New simplification procedure for solving continuity conditions; it
  2534 is much faster on terms with many nested lambda abstractions (cubic
  2535 instead of exponential time).
  2536 
  2537 * New syntax for domain package: selector names are now optional.
  2538 Parentheses should be omitted unless argument is lazy, for example:
  2539 
  2540   domain 'a stream = cons "'a" (lazy "'a stream")
  2541 
  2542 * New command 'fixrec' for defining recursive functions with pattern
  2543 matching; defining multiple functions with mutual recursion is also
  2544 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2545 sinr, or any data constructor defined by the domain package. The given
  2546 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2547 syntax and examples.
  2548 
  2549 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2550 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2551 but the proof obligation additionally includes an admissibility
  2552 requirement. The packages generate instances of class cpo or pcpo,
  2553 with continuity and strictness theorems for Rep and Abs.
  2554 
  2555 * HOLCF: Many theorems have been renamed according to a more standard naming
  2556 scheme (INCOMPATIBILITY):
  2557 
  2558   foo_inject:  "foo$x = foo$y ==> x = y"
  2559   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2560   foo_less:    "(foo$x << foo$y) = (x << y)"
  2561   foo_strict:  "foo$UU = UU"
  2562   foo_defined: "... ==> foo$x ~= UU"
  2563   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2564 
  2565 
  2566 *** ZF ***
  2567 
  2568 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2569 including the First Isomorphism Theorem (on quotienting by the kernel
  2570 of a homomorphism).
  2571 
  2572 * ZF/Simplifier: install second copy of type solver that actually
  2573 makes use of TC rules declared to Isar proof contexts (or locales);
  2574 the old version is still required for ML proof scripts.
  2575 
  2576 
  2577 *** Cube ***
  2578 
  2579 * Converted to Isar theory format; use locales instead of axiomatic
  2580 theories.
  2581 
  2582 
  2583 *** ML ***
  2584 
  2585 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2586 for ||>, ||>>, |>>,
  2587 
  2588 * Pure/library.ML no longer defines its own option datatype, but uses
  2589 that of the SML basis, which has constructors NONE and SOME instead of
  2590 None and Some, as well as exception Option.Option instead of OPTION.
  2591 The functions the, if_none, is_some, is_none have been adapted
  2592 accordingly, while Option.map replaces apsome.
  2593 
  2594 * Pure/library.ML: the exception LIST has been given up in favour of
  2595 the standard exceptions Empty and Subscript, as well as
  2596 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2597 superceded by the standard hd and tl functions etc.
  2598 
  2599 A number of basic list functions are no longer exported to the ML
  2600 toplevel, as they are variants of predefined functions.  The following
  2601 suggests how one can translate existing code:
  2602 
  2603     rev_append xs ys = List.revAppend (xs, ys)
  2604     nth_elem (i, xs) = List.nth (xs, i)
  2605     last_elem xs = List.last xs
  2606     flat xss = List.concat xss
  2607     seq fs = List.app fs
  2608     partition P xs = List.partition P xs
  2609     mapfilter f xs = List.mapPartial f xs
  2610 
  2611 * Pure/library.ML: several combinators for linear functional
  2612 transformations, notably reverse application and composition:
  2613 
  2614   x |> f                f #> g
  2615   (x, y) |-> f          f #-> g
  2616 
  2617 * Pure/library.ML: introduced/changed precedence of infix operators:
  2618 
  2619   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2620   infix 2 ?;
  2621   infix 3 o oo ooo oooo;
  2622   infix 4 ~~ upto downto;
  2623 
  2624 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2625 infix operators.
  2626 
  2627 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2628 fold_map support linear functional transformations and nesting.  For
  2629 example:
  2630 
  2631   fold f [x1, ..., xN] y =
  2632     y |> f x1 |> ... |> f xN
  2633 
  2634   (fold o fold) f [xs1, ..., xsN] y =
  2635     y |> fold f xs1 |> ... |> fold f xsN
  2636 
  2637   fold f [x1, ..., xN] =
  2638     f x1 #> ... #> f xN
  2639 
  2640   (fold o fold) f [xs1, ..., xsN] =
  2641     fold f xs1 #> ... #> fold f xsN
  2642 
  2643 * Pure/library.ML: the following selectors on type 'a option are
  2644 available:
  2645 
  2646   the:               'a option -> 'a  (*partial*)
  2647   these:             'a option -> 'a  where 'a = 'b list
  2648   the_default: 'a -> 'a option -> 'a
  2649   the_list:          'a option -> 'a list
  2650 
  2651 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2652 basic operations for association lists, following natural argument
  2653 order; moreover the explicit equality predicate passed here avoids
  2654 potentially expensive polymorphic runtime equality checks.
  2655 The old functions may be expressed as follows:
  2656 
  2657   assoc = uncurry (AList.lookup (op =))
  2658   assocs = these oo AList.lookup (op =)
  2659   overwrite = uncurry (AList.update (op =)) o swap
  2660 
  2661 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2662 
  2663   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2664   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2665 
  2666 replacing make_keylist and keyfilter (occassionally used)
  2667 Naive rewrites:
  2668 
  2669   make_keylist = AList.make
  2670   keyfilter = AList.find (op =)
  2671 
  2672 * eq_fst and eq_snd now take explicit equality parameter, thus
  2673   avoiding eqtypes. Naive rewrites:
  2674 
  2675     eq_fst = eq_fst (op =)
  2676     eq_snd = eq_snd (op =)
  2677 
  2678 * Removed deprecated apl and apr (rarely used).
  2679   Naive rewrites:
  2680 
  2681     apl (n, op) =>>= curry op n
  2682     apr (op, m) =>>= fn n => op (n, m)
  2683 
  2684 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2685 provides a reasonably efficient light-weight implementation of sets as
  2686 lists.
  2687 
  2688 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2689 few new operations; existing lookup and update are now curried to
  2690 follow natural argument order (for use with fold etc.);
  2691 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2692 
  2693 * Pure/General: output via the Isabelle channels of
  2694 writeln/warning/error etc. is now passed through Output.output, with a
  2695 hook for arbitrary transformations depending on the print_mode
  2696 (cf. Output.add_mode -- the first active mode that provides a output
  2697 function wins).  Already formatted output may be embedded into further
  2698 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2699 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2700 accommodate easy composition of diagnostic messages etc.  Programmers
  2701 rarely need to care about Output.output or Output.raw at all, with
  2702 some notable exceptions: Output.output is required when bypassing the
  2703 standard channels (writeln etc.), or in token translations to produce
  2704 properly formatted results; Output.raw is required when capturing
  2705 already output material that will eventually be presented to the user
  2706 a second time.  For the default print mode, both Output.output and
  2707 Output.raw have no effect.
  2708 
  2709 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2710 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2711 cumulative results are displayed at the end of a batch session.
  2712 
  2713 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2714 replaced by File.platform_path and File.shell_path (with appropriate
  2715 hooks).  This provides a clean interface for unusual systems where the
  2716 internal and external process view of file names are different.
  2717 
  2718 * Pure: more efficient orders for basic syntactic entities: added
  2719 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2720 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2721 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2722 orders now -- potential INCOMPATIBILITY for code that depends on a
  2723 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2724 Library.sort_strings on result).
  2725 
  2726 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2727 fold_types traverse types/terms from left to right, observing natural
  2728 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2729 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2730 
  2731 * Pure: name spaces have been refined, with significant changes of the
  2732 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2733 to extern(_table).  The plain name entry path is superceded by a
  2734 general 'naming' context, which also includes the 'policy' to produce
  2735 a fully qualified name and external accesses of a fully qualified
  2736 name; NameSpace.extend is superceded by context dependent
  2737 Sign.declare_name.  Several theory and proof context operations modify
  2738 the naming context.  Especially note Theory.restore_naming and
  2739 ProofContext.restore_naming to get back to a sane state; note that
  2740 Theory.add_path is no longer sufficient to recover from
  2741 Theory.absolute_path in particular.
  2742 
  2743 * Pure: new flags short_names (default false) and unique_names
  2744 (default true) for controlling output of qualified names.  If
  2745 short_names is set, names are printed unqualified.  If unique_names is
  2746 reset, the name prefix is reduced to the minimum required to achieve
  2747 the original result when interning again, even if there is an overlap
  2748 with earlier declarations.
  2749 
  2750 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2751 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2752 (useful for printing error messages).  INCOMPATIBILITY.
  2753 
  2754 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2755 Theory.theory are now identified, referring to the universal
  2756 Context.theory (see Pure/context.ML).  Actual signature and theory
  2757 content is managed as theory data.  The old code and interfaces were
  2758 spread over many files and structures; the new arrangement introduces
  2759 considerable INCOMPATIBILITY to gain more clarity:
  2760 
  2761   Context -- theory management operations (name, identity, inclusion,
  2762     parents, ancestors, merge, etc.), plus generic theory data;
  2763 
  2764   Sign -- logical signature and syntax operations (declaring consts,
  2765     types, etc.), plus certify/read for common entities;
  2766 
  2767   Theory -- logical theory operations (stating axioms, definitions,
  2768     oracles), plus a copy of logical signature operations (consts,
  2769     types, etc.); also a few basic management operations (Theory.copy,
  2770     Theory.merge, etc.)
  2771 
  2772 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2773 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2774 for convenience -- they merely return the theory.
  2775 
  2776 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2777 
  2778 * Pure: the Isar proof context type is already defined early in Pure
  2779 as Context.proof (note that ProofContext.context and Proof.context are
  2780 aliases, where the latter is the preferred name).  This enables other
  2781 Isabelle components to refer to that type even before Isar is present.
  2782 
  2783 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2784 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2785 any of these kinds.  For example, Sign.intern typeK is now
  2786 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2787 Theory.hide_types.  Also note that former
  2788 Theory.hide_classes/types/consts are now
  2789 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2790 internalize their arguments!  INCOMPATIBILITY.
  2791 
  2792 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2793 datatype thmref (with constructors Name and NameSelection) instead of
  2794 plain string -- INCOMPATIBILITY;
  2795 
  2796 * Pure: cases produced by proof methods specify options, where NONE
  2797 means to remove case bindings -- INCOMPATIBILITY in
  2798 (RAW_)METHOD_CASES.
  2799 
  2800 * Pure: the following operations retrieve axioms or theorems from a
  2801 theory node or theory hierarchy, respectively:
  2802 
  2803   Theory.axioms_of: theory -> (string * term) list
  2804   Theory.all_axioms_of: theory -> (string * term) list
  2805   PureThy.thms_of: theory -> (string * thm) list
  2806   PureThy.all_thms_of: theory -> (string * thm) list
  2807 
  2808 * Pure: print_tac now outputs the goal through the trace channel.
  2809 
  2810 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2811 Reference Toplevel.debug (default false) controls detailed printing
  2812 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2813 controls execution profiling -- set to 1 for time and 2 for space
  2814 (both increase the runtime).
  2815 
  2816 * Isar session: The initial use of ROOT.ML is now always timed,
  2817 i.e. the log will show the actual process times, in contrast to the
  2818 elapsed wall-clock time that the outer shell wrapper produces.
  2819 
  2820 * Simplifier: improved handling of bound variables (nameless
  2821 representation, avoid allocating new strings).  Simprocs that invoke
  2822 the Simplifier recursively should use Simplifier.inherit_bounds to
  2823 avoid local name clashes.  Failure to do so produces warnings
  2824 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2825 for further details.
  2826 
  2827 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2828 bindings for all theorems stored within a given theory; this may help
  2829 in porting non-Isar theories to Isar ones, while keeping ML proof
  2830 scripts for the time being.
  2831 
  2832 * ML operator HTML.with_charset specifies the charset begin used for
  2833 generated HTML files.  For example:
  2834 
  2835   HTML.with_charset "utf-8" use_thy "Hebrew";
  2836   HTML.with_charset "utf-8" use_thy "Chinese";
  2837 
  2838 
  2839 *** System ***
  2840 
  2841 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2842 isabelle, isatool etc.).
  2843 
  2844 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2845 isatool doc, isatool mkdir, display_drafts etc.).
  2846 
  2847 * isatool usedir: option -f allows specification of the ML file to be
  2848 used by Isabelle; default is ROOT.ML.
  2849 
  2850 * New isatool version outputs the version identifier of the Isabelle
  2851 distribution being used.
  2852 
  2853 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2854 (containing Boolean satisfiability problems) into Isabelle/HOL
  2855 theories.
  2856 
  2857 
  2858 
  2859 New in Isabelle2004 (April 2004)
  2860 --------------------------------
  2861 
  2862 *** General ***
  2863 
  2864 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2865   Replaces linorder.ML.
  2866 
  2867 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2868   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2869   (\<a>...\<z>), are now considered normal letters, and can therefore
  2870   be used anywhere where an ASCII letter (a...zA...Z) has until
  2871   now. COMPATIBILITY: This obviously changes the parsing of some
  2872   terms, especially where a symbol has been used as a binder, say
  2873   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2874   as an identifier.  Fix it by inserting a space around former
  2875   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2876   existing theory and ML files.
  2877 
  2878 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2879 
  2880 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2881   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2882   a normal (but invisible) letter. For multiple letter subscripts repeat
  2883   \<^isub> like this: x\<^isub>1\<^isub>2.
  2884 
  2885 * Pure: There are now sub-/superscripts that can span more than one
  2886   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2887   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2888   superscript. The new control characters are not identifier parts.
  2889 
  2890 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2891   content of "..." to the latex file instead of \isacntrl... . The "..."
  2892   may consist of any printable characters excluding the end bracket >.
  2893 
  2894 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2895   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2896   declare constants "final", which prevents their being given a definition
  2897   later.  It is useful for constants whose behaviour is fixed axiomatically
  2898   rather than definitionally, such as the meta-logic connectives.
  2899 
  2900 * Pure: 'instance' now handles general arities with general sorts
  2901   (i.e. intersections of classes),
  2902 
  2903 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2904   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2905   It can be changed to alter the colors/layout of generated pages.
  2906 
  2907 
  2908 *** Isar ***
  2909 
  2910 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2911   cut_tac, subgoal_tac and thin_tac:
  2912   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2913     locales are no longer forced to write Isar proof scripts.
  2914     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2915     emulations.
  2916   - INCOMPATIBILITY: names of variables to be instantiated may no
  2917     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2918     This is consistent with the instantiation attribute "where".
  2919 
  2920 * Attributes "where" and "of":
  2921   - Now take type variables of instantiated theorem into account when reading
  2922     the instantiation string.  This fixes a bug that caused instantiated
  2923     theorems to have too special types in some circumstances.
  2924   - "where" permits explicit instantiations of type variables.
  2925 
  2926 * Calculation commands "moreover" and "also" no longer interfere with
  2927   current facts ("this"), admitting arbitrary combinations with "then"
  2928   and derived forms.
  2929 
  2930 * Locales:
  2931   - Goal statements involving the context element "includes" no longer
  2932     generate theorems with internal delta predicates (those ending on
  2933     "_axioms") in the premise.
  2934     Resolve particular premise with <locale>.intro to obtain old form.
  2935   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2936     specification and "includes" elements in goal statement.
  2937   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2938     [intro?] and [elim?] (respectively) by default.
  2939   - Experimental command for instantiation of locales in proof contexts:
  2940         instantiate <label>[<attrs>]: <loc>
  2941     Instantiates locale <loc> and adds all its theorems to the current context
  2942     taking into account their attributes.  Label and attrs are optional
  2943     modifiers, like in theorem declarations.  If present, names of
  2944     instantiated theorems are qualified with <label>, and the attributes
  2945     <attrs> are applied after any attributes these theorems might have already.
  2946       If the locale has assumptions, a chained fact of the form
  2947     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2948     are derived.  The command does not support old-style locales declared
  2949     with "locale (open)".
  2950       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2951 
  2952 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2953   (Isar) contexts.
  2954 
  2955 
  2956 *** HOL ***
  2957 
  2958 * Proof import: new image HOL4 contains the imported library from
  2959   the HOL4 system with about 2500 theorems. It is imported by
  2960   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2961   can be used like any other Isabelle image.  See
  2962   HOL/Import/HOL/README for more information.
  2963 
  2964 * Simplifier:
  2965   - Much improved handling of linear and partial orders.
  2966     Reasoners for linear and partial orders are set up for type classes
  2967     "linorder" and "order" respectively, and are added to the default simpset
  2968     as solvers.  This means that the simplifier can build transitivity chains
  2969     to solve goals from the assumptions.
  2970   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2971     of blast or auto after simplification become unnecessary because the goal
  2972     is solved by simplification already.
  2973 
  2974 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2975     all proved in axiomatic type classes for semirings, rings and fields.
  2976 
  2977 * Numerics:
  2978   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2979     now formalized using the Ring_and_Field theory mentioned above.
  2980   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2981     than before, because now they are set up once in a generic manner.
  2982   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2983     Look for the general versions in Ring_and_Field (and Power if they concern
  2984     exponentiation).
  2985 
  2986 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2987 
  2988 * Records:
  2989   - Record types are now by default printed with their type abbreviation
  2990     instead of the list of all field types. This can be configured via
  2991     the reference "print_record_type_abbr".
  2992   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2993     (not enabled by default).
  2994   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2995     EX x. x = sel r to True (not enabled by default).
  2996   - Tactic "record_split_simp_tac" to split and simplify records added.
  2997 
  2998 * 'specification' command added, allowing for definition by
  2999   specification.  There is also an 'ax_specification' command that
  3000   introduces the new constants axiomatically.
  3001 
  3002 * arith(_tac) is now able to generate counterexamples for reals as well.
  3003 
  3004 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3005 
  3006 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3007   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3008 
  3009 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3010   matrix theory to linear programming.
  3011 
  3012 * Unions and Intersections:
  3013   The latex output syntax of UN and INT has been changed
  3014   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3015   i.e. the index formulae has become a subscript.
  3016   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3017 
  3018 * Unions and Intersections over Intervals:
  3019   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3020   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3021   like in normal math, and corresponding versions for < and for intersection.
  3022 
  3023 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3024   lexicographic dictonary ordering has been added as "lexord".
  3025 
  3026 * ML: the legacy theory structures Int and List have been removed. They had
  3027   conflicted with ML Basis Library structures having the same names.
  3028 
  3029 * 'refute' command added to search for (finite) countermodels.  Only works
  3030   for a fragment of HOL.  The installation of an external SAT solver is
  3031   highly recommended.  See "HOL/Refute.thy" for details.
  3032 
  3033 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3034   formulae under an assignment of free variables to random values.
  3035   In contrast to 'refute', it can deal with inductive datatypes,
  3036   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3037   for examples.
  3038 
  3039 
  3040 *** HOLCF ***
  3041 
  3042 * Streams now come with concatenation and are part of the HOLCF image
  3043 
  3044 
  3045 
  3046 New in Isabelle2003 (May 2003)
  3047 ------------------------------
  3048 
  3049 *** General ***
  3050 
  3051 * Provers/simplifier:
  3052 
  3053   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3054     Assumptions are now subject to complete mutual simplification,
  3055     not just from left to right. The simplifier now preserves
  3056     the order of assumptions.
  3057 
  3058     Potential INCOMPATIBILITY:
  3059 
  3060     -- simp sometimes diverges where the old version did
  3061        not, e.g. invoking simp on the goal
  3062 
  3063         [| P (f x); y = x; f x = f y |] ==> Q
  3064 
  3065        now gives rise to the infinite reduction sequence
  3066 
  3067         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3068 
  3069        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3070        kind of problem.
  3071 
  3072     -- Tactics combining classical reasoner and simplification (such as auto)
  3073        are also affected by this change, because many of them rely on
  3074        simp. They may sometimes diverge as well or yield a different numbers
  3075        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3076        in case of problems. Sometimes subsequent calls to the classical
  3077        reasoner will fail because a preceeding call to the simplifier too
  3078        eagerly simplified the goal, e.g. deleted redundant premises.
  3079 
  3080   - The simplifier trace now shows the names of the applied rewrite rules
  3081 
  3082   - You can limit the number of recursive invocations of the simplifier
  3083     during conditional rewriting (where the simplifie tries to solve the
  3084     conditions before applying the rewrite rule):
  3085     ML "simp_depth_limit := n"
  3086     where n is an integer. Thus you can force termination where previously
  3087     the simplifier would diverge.
  3088 
  3089   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3090 
  3091   - No longer aborts on failed congruence proof.  Instead, the
  3092     congruence is ignored.
  3093 
  3094 * Pure: New generic framework for extracting programs from constructive
  3095   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3096   as HOL/Extraction for some case studies.
  3097 
  3098 * Pure: The main goal of the proof state is no longer shown by default, only
  3099 the subgoals. This behaviour is controlled by a new flag.
  3100    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3101 (ML: Proof.show_main_goal).
  3102 
  3103 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3104 rules whose conclusion matches subgoal 1:
  3105       PG menu: Isabelle/Isar -> Show me -> matching rules
  3106 The rules are ordered by how closely they match the subgoal.
  3107 In particular, rules that solve a subgoal outright are displayed first
  3108 (or rather last, the way they are printed).
  3109 (ML: ProofGeneral.print_intros())
  3110 
  3111 * Pure: New flag trace_unify_fail causes unification to print
  3112 diagnostic information (PG: in trace buffer) when it fails. This is
  3113 useful for figuring out why single step proofs like rule, erule or
  3114 assumption failed.
  3115 
  3116 * Pure: Locale specifications now produce predicate definitions
  3117 according to the body of text (covering assumptions modulo local
  3118 definitions); predicate "loc_axioms" covers newly introduced text,
  3119 while "loc" is cumulative wrt. all included locale expressions; the
  3120 latter view is presented only on export into the global theory
  3121 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3122 on the old view without predicates;
  3123 
  3124 * Pure: predefined locales "var" and "struct" are useful for sharing
  3125 parameters (as in CASL, for example); just specify something like
  3126 ``var x + var y + struct M'' as import;
  3127 
  3128 * Pure: improved thms_containing: proper indexing of facts instead of
  3129 raw theorems; check validity of results wrt. current name space;
  3130 include local facts of proof configuration (also covers active
  3131 locales), cover fixed variables in index; may use "_" in term
  3132 specification; an optional limit for the number of printed facts may
  3133 be given (the default is 40);
  3134 
  3135 * Pure: disallow duplicate fact bindings within new-style theory files
  3136 (batch-mode only);
  3137 
  3138 * Provers: improved induct method: assumptions introduced by case
  3139 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3140 the goal statement); "foo" still refers to all facts collectively;
  3141 
  3142 * Provers: the function blast.overloaded has been removed: all constants
  3143 are regarded as potentially overloaded, which improves robustness in exchange
  3144 for slight decrease in efficiency;
  3145 
  3146 * Provers/linorder: New generic prover for transitivity reasoning over
  3147 linear orders.  Note: this prover is not efficient!
  3148 
  3149 * Isar: preview of problems to finish 'show' now produce an error
  3150 rather than just a warning (in interactive mode);
  3151 
  3152 
  3153 *** HOL ***
  3154 
  3155 * arith(_tac)
  3156 
  3157  - Produces a counter example if it cannot prove a goal.
  3158    Note that the counter example may be spurious if the goal is not a formula
  3159    of quantifier-free linear arithmetic.
  3160    In ProofGeneral the counter example appears in the trace buffer.
  3161 
  3162  - Knows about div k and mod k where k is a numeral of type nat or int.
  3163 
  3164  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3165    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3166    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3167 
  3168 * simp's arithmetic capabilities have been enhanced a bit: it now
  3169 takes ~= in premises into account (by performing a case split);
  3170 
  3171 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3172 are distributed over a sum of terms;
  3173 
  3174 * New tactic "trans_tac" and method "trans" instantiate
  3175 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3176 "<=", "<" and "=").
  3177 
  3178 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3179 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3180 
  3181 * 'typedef' command has new option "open" to suppress the set
  3182 definition;
  3183 
  3184 * functions Min and Max on finite sets have been introduced (theory
  3185 Finite_Set);
  3186 
  3187 * attribute [symmetric] now works for relations as well; it turns
  3188 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3189 
  3190 * induct over a !!-quantified statement (say !!x1..xn):
  3191   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3192 
  3193 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3194 %x. None. Warning: empty_def now refers to the previously hidden definition
  3195 of the empty set.
  3196 
  3197 * Algebra: formalization of classical algebra.  Intended as base for
  3198 any algebraic development in Isabelle.  Currently covers group theory
  3199 (up to Sylow's theorem) and ring theory (Universal Property of
  3200 Univariate Polynomials).  Contributions welcome;
  3201 
  3202 * GroupTheory: deleted, since its material has been moved to Algebra;
  3203 
  3204 * Complex: new directory of the complex numbers with numeric constants,
  3205 nonstandard complex numbers, and some complex analysis, standard and
  3206 nonstandard (Jacques Fleuriot);
  3207 
  3208 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3209 
  3210 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3211 Fleuriot);
  3212 
  3213 * Real/HahnBanach: updated and adapted to locales;
  3214 
  3215 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3216 Gray and Kramer);
  3217 
  3218 * UNITY: added the Meier-Sanders theory of progress sets;
  3219 
  3220 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3221 as abstract algorithms, instantiated to the JVM;
  3222 
  3223 * Bali: Java source language formalization. Type system, operational
  3224 semantics, axiomatic semantics. Supported language features:
  3225 classes, interfaces, objects,virtual methods, static methods,
  3226 static/instance fields, arrays, access modifiers, definite
  3227 assignment, exceptions.
  3228 
  3229 
  3230 *** ZF ***
  3231 
  3232 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3233 universe, etc.);
  3234 
  3235 * Main ZF: virtually all theories converted to new-style format;
  3236 
  3237 
  3238 *** ML ***
  3239 
  3240 * Pure: Tactic.prove provides sane interface for internal proofs;
  3241 omits the infamous "standard" operation, so this is more appropriate
  3242 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3243 
  3244 * Pure: improved error reporting of simprocs;
  3245 
  3246 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3247 up simprocs;
  3248 
  3249 
  3250 *** Document preparation ***
  3251 
  3252 * uses \par instead of \\ for line breaks in theory text. This may
  3253 shift some page breaks in large documents. To get the old behaviour
  3254 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3255 
  3256 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3257 other packages
  3258 
  3259 * \<euro> now needs package babel/greek instead of marvosym (which
  3260 broke \Rightarrow)
  3261 
  3262 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3263 textcomp package)
  3264 
  3265 
  3266 
  3267 New in Isabelle2002 (March 2002)
  3268 --------------------------------
  3269 
  3270 *** Document preparation ***
  3271 
  3272 * greatly simplified document preparation setup, including more
  3273 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3274 instructive isatool mkdir; users should basically be able to get
  3275 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3276 users may run a separate document processing stage manually like this:
  3277 "isatool usedir -D output HOL Test && isatool document Test/output";
  3278 
  3279 * theory dependency graph may now be incorporated into documents;
  3280 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3281 with \includegraphics of LaTeX;
  3282 
  3283 * proper spacing of consecutive markup elements, especially text
  3284 blocks after section headings;
  3285 
  3286 * support bold style (for single symbols only), input syntax is like
  3287 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3288 
  3289 * \<bullet> is now output as bold \cdot by default, which looks much
  3290 better in printed text;
  3291 
  3292 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3293 note that these symbols are currently unavailable in Proof General /
  3294 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3295 
  3296 * isatool latex no longer depends on changed TEXINPUTS, instead
  3297 isatool document copies the Isabelle style files to the target
  3298 location;
  3299 
  3300 
  3301 *** Isar ***
  3302 
  3303 * Pure/Provers: improved proof by cases and induction;
  3304   - 'case' command admits impromptu naming of parameters (such as
  3305     "case (Suc n)");
  3306   - 'induct' method divinates rule instantiation from the inductive
  3307     claim; no longer requires excessive ?P bindings for proper
  3308     instantiation of cases;
  3309   - 'induct' method properly enumerates all possibilities of set/type
  3310     rules; as a consequence facts may be also passed through *type*
  3311     rules without further ado;
  3312   - 'induct' method now derives symbolic cases from the *rulified*
  3313     rule (before it used to rulify cases stemming from the internal
  3314     atomized version); this means that the context of a non-atomic
  3315     statement becomes is included in the hypothesis, avoiding the
  3316     slightly cumbersome show "PROP ?case" form;
  3317   - 'induct' may now use elim-style induction rules without chaining
  3318     facts, using ``missing'' premises from the goal state; this allows
  3319     rules stemming from inductive sets to be applied in unstructured
  3320     scripts, while still benefitting from proper handling of non-atomic
  3321     statements; NB: major inductive premises need to be put first, all
  3322     the rest of the goal is passed through the induction;
  3323   - 'induct' proper support for mutual induction involving non-atomic
  3324     rule statements (uses the new concept of simultaneous goals, see
  3325     below);
  3326   - append all possible rule selections, but only use the first
  3327     success (no backtracking);
  3328   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3329   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3330   - added 'print_induct_rules' (covered by help item in recent Proof
  3331     General versions);
  3332   - moved induct/cases attributes to Pure, methods to Provers;
  3333   - generic method setup instantiated for FOL and HOL;
  3334 
  3335 * Pure: support multiple simultaneous goal statements, for example
  3336 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3337 meta-level mechanism, this acts as if several individual goals had
  3338 been stated separately; in particular common proof methods need to be
  3339 repeated in order to cover all claims; note that a single elimination
  3340 step is *not* sufficient to establish the two conjunctions, so this
  3341 fails:
  3342 
  3343   assume "A & B" then have A and B ..   (*".." fails*)
  3344 
  3345 better use "obtain" in situations as above; alternative refer to
  3346 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3347 
  3348 * Pure: proper integration with ``locales''; unlike the original
  3349 version by Florian Kammller, Isar locales package high-level proof
  3350 contexts rather than raw logical ones (e.g. we admit to include
  3351 attributes everywhere); operations on locales include merge and
  3352 rename; support for implicit arguments (``structures''); simultaneous
  3353 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3354 some examples;
  3355 
  3356 * Pure: the following commands have been ``localized'', supporting a
  3357 target locale specification "(in name)": 'lemma', 'theorem',
  3358 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3359 stored both within the locale and at the theory level (exported and
  3360 qualified by the locale name);
  3361 
  3362 * Pure: theory goals may now be specified in ``long'' form, with
  3363 ad-hoc contexts consisting of arbitrary locale elements. for example
  3364 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3365 definitions may be given, too); the result is a meta-level rule with
  3366 the context elements being discharged in the obvious way;
  3367 
  3368 * Pure: new proof command 'using' allows to augment currently used
  3369 facts after a goal statement ('using' is syntactically analogous to
  3370 'apply', but acts on the goal's facts only); this allows chained facts
  3371 to be separated into parts given before and after a claim, as in
  3372 ``from a and b have C using d and e <proof>'';
  3373 
  3374 * Pure: renamed "antecedent" case to "rule_context";
  3375 
  3376 * Pure: new 'judgment' command records explicit information about the
  3377 object-logic embedding (used by several tools internally); no longer
  3378 use hard-wired "Trueprop";
  3379 
  3380 * Pure: added 'corollary' command;
  3381 
  3382 * Pure: fixed 'token_translation' command;
  3383 
  3384 * Pure: removed obsolete 'exported' attribute;
  3385 
  3386 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3387 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3388 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3389 
  3390 * Pure: method 'atomize' presents local goal premises as object-level
  3391 statements (atomic meta-level propositions); setup controlled via
  3392 rewrite rules declarations of 'atomize' attribute; example
  3393 application: 'induct' method with proper rule statements in improper
  3394 proof *scripts*;
  3395 
  3396 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3397 now consider the syntactic context of assumptions, giving a better
  3398 chance to get type-inference of the arguments right (this is
  3399 especially important for locales);
  3400 
  3401 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3402 mode;
  3403 
  3404 * Pure/obtain: the formal conclusion "thesis", being marked as
  3405 ``internal'', may no longer be reference directly in the text;
  3406 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3407 situations;
  3408 
  3409 * Pure: generic 'sym' attribute which declares a rule both as pure
  3410 'elim?' and for the 'symmetric' operation;
  3411 
  3412 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3413 text; the fixed correlation with particular command syntax has been
  3414 discontinued;
  3415 
  3416 * Pure: new method 'rules' is particularly well-suited for proof
  3417 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3418 but often produces more compact proof terms with less detours;
  3419 
  3420 * Pure/Provers/classical: simplified integration with pure rule
  3421 attributes and methods; the classical "intro?/elim?/dest?"
  3422 declarations coincide with the pure ones; the "rule" method no longer
  3423 includes classically swapped intros; "intro" and "elim" methods no
  3424 longer pick rules from the context; also got rid of ML declarations
  3425 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3426 INCOMPATIBILITY;
  3427 
  3428 * Provers/classical: attribute 'swapped' produces classical inversions
  3429 of introduction rules;
  3430 
  3431 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3432 rules instead of full simplifier context; 'iff' attribute handles
  3433 conditional rules;
  3434 
  3435 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3436 
  3437 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3438 "(permissive)" option to recover old behavior;
  3439 
  3440 * HOL: 'inductive' no longer features separate (collective) attributes
  3441 for 'intros' (was found too confusing);
  3442 
  3443 * HOL: properly declared induction rules less_induct and
  3444 wf_induct_rule;
  3445 
  3446 
  3447 *** HOL ***
  3448 
  3449 * HOL: moved over to sane numeral syntax; the new policy is as
  3450 follows:
  3451 
  3452   - 0 and 1 are polymorphic constants, which are defined on any
  3453   numeric type (nat, int, real etc.);
  3454 
  3455   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3456   binary representation internally;
  3457 
  3458   - type nat has special constructor Suc, and generally prefers Suc 0
  3459   over 1::nat and Suc (Suc 0) over 2::nat;
  3460 
  3461 This change may cause significant problems of INCOMPATIBILITY; here
  3462 are some hints on converting existing sources:
  3463 
  3464   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3465   entities, so expressions involving "-" (unary or binary minus) need
  3466   to be spaced properly;
  3467 
  3468   - existing occurrences of "1" may need to be constraint "1::nat" or
  3469   even replaced by Suc 0; similar for old "2";
  3470 
  3471   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3472 
  3473   - remove all special provisions on numerals in proofs;
  3474 
  3475 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3476 representation (depends on bin_arith_simps in the default context);
  3477 
  3478 * HOL: symbolic syntax for x^2 (numeral 2);
  3479 
  3480 * HOL: the class of all HOL types is now called "type" rather than
  3481 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3482 in axclass/classes, instance/arities, and (usually rare) occurrences
  3483 in typings (of consts etc.); internally the class is called
  3484 "HOL.type", ML programs should refer to HOLogic.typeS;
  3485 
  3486 * HOL/record package improvements:
  3487   - new derived operations "fields" to build a partial record section,
  3488     "extend" to promote a fixed record to a record scheme, and
  3489     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3490     declared as simp by default;
  3491   - shared operations ("more", "fields", etc.) now need to be always
  3492     qualified) --- potential INCOMPATIBILITY;
  3493   - removed "make_scheme" operations (use "make" with "extend") --
  3494     INCOMPATIBILITY;
  3495   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3496   - provides cases/induct rules for use with corresponding Isar
  3497     methods (for concrete records, record schemes, concrete more
  3498     parts, and schematic more parts -- in that order);
  3499   - internal definitions directly based on a light-weight abstract
  3500     theory of product types over typedef rather than datatype;
  3501 
  3502 * HOL: generic code generator for generating executable ML code from
  3503 specifications; specific support for HOL constructs such as inductive
  3504 datatypes and sets, as well as recursive functions; can be invoked
  3505 via 'generate_code' theory section;
  3506 
  3507 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3508 
  3509 * HOL: consolidated and renamed several theories.  In particular:
  3510         Ord.thy has been absorbed into HOL.thy
  3511         String.thy has been absorbed into List.thy
  3512 
  3513 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3514 (beware of argument permutation!);
  3515 
  3516 * HOL: linorder_less_split superseded by linorder_cases;
  3517 
  3518 * HOL/List: "nodups" renamed to "distinct";
  3519 
  3520 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3521 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3522   - Ex_def has changed, now need to use some_eq_ex
  3523 
  3524 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3525 in this (rare) case use:
  3526 
  3527   delSWrapper "split_all_tac"
  3528   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3529 
  3530 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3531 MAY FAIL;
  3532 
  3533 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3534 Isabelle's type classes, ^ on functions and relations has too general
  3535 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3536 necessary to attach explicit type constraints;
  3537 
  3538 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3539 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3540 renamed accordingly (eg "compI" -> "rel_compI").
  3541 
  3542 * HOL: syntax translations now work properly with numerals and records
  3543 expressions;
  3544 
  3545 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3546 of "lam" -- INCOMPATIBILITY;
  3547 
  3548 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3549 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3550 renamed "Product_Type.unit";
  3551 
  3552 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3553 
  3554 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3555 the "cases" method);
  3556 
  3557 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3558 Florian Kammller);
  3559 
  3560 * HOL/IMP: updated and converted to new-style theory format; several
  3561 parts turned into readable document, with proper Isar proof texts and
  3562 some explanations (by Gerwin Klein);
  3563 
  3564 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3565 
  3566 * HOL-Hyperreal is now a logic image;
  3567 
  3568 
  3569 *** HOLCF ***
  3570 
  3571 * Isar: consts/constdefs supports mixfix syntax for continuous
  3572 operations;
  3573 
  3574 * Isar: domain package adapted to new-style theory format, e.g. see
  3575 HOLCF/ex/Dnat.thy;
  3576 
  3577 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3578 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3579 lift.induct_tac, always use UU instead of Undef;
  3580 
  3581 * HOLCF/IMP: updated and converted to new-style theory;
  3582 
  3583 
  3584 *** ZF ***
  3585 
  3586 * Isar: proper integration of logic-specific tools and packages,
  3587 including theory commands '(co)inductive', '(co)datatype',
  3588 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3589 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3590 
  3591 * theory Main no longer includes AC; for the Axiom of Choice, base
  3592 your theory on Main_ZFC;
  3593 
  3594 * the integer library now covers quotients and remainders, with many
  3595 laws relating division to addition, multiplication, etc.;
  3596 
  3597 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3598 typeless version of the formalism;
  3599 
  3600 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3601 format;
  3602 
  3603 * ZF/Induct: new directory for examples of inductive definitions,
  3604 including theory Multiset for multiset orderings; converted to
  3605 new-style theory format;
  3606 
  3607 * ZF: many new theorems about lists, ordinals, etc.;
  3608 
  3609 
  3610 *** General ***
  3611 
  3612 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3613 variable proof controls level of detail: 0 = no proofs (only oracle
  3614 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3615 also ref manual for further ML interfaces;
  3616 
  3617 * Pure/axclass: removed obsolete ML interface
  3618 goal_subclass/goal_arity;
  3619 
  3620 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3621 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3622 separate tokens, so expressions involving minus need to be spaced
  3623 properly;
  3624 
  3625 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3626 rather than "infixl" or "infixr";
  3627 
  3628 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3629 sort constraint specifications in type inference; e.g. "x::_::foo"
  3630 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3631 type variable);
  3632 
  3633 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3634 control output of nested => (types); the default behavior is
  3635 "type_brackets";
  3636 
  3637 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3638 tokens into AST constants;
  3639 
  3640 * Pure/syntax: prefer later declarations of translations and print
  3641 translation functions; potential INCOMPATIBILITY: need to reverse
  3642 multiple declarations for same syntax element constant;
  3643 
  3644 * Pure/show_hyps reset by default (in accordance to existing Isar
  3645 practice);
  3646 
  3647 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3648 addSafter;
  3649 
  3650 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3651 as well;
  3652 
  3653 * system: tested support for MacOS X; should be able to get Isabelle +
  3654 Proof General to work in a plain Terminal after installing Poly/ML
  3655 (e.g. from the Isabelle distribution area) and GNU bash alone
  3656 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3657 support requires further installations, e.g. from
  3658 http://fink.sourceforge.net/);
  3659 
  3660 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3661 
  3662 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3663 of 40 MB), cf. ML_OPTIONS;
  3664 
  3665 * system: Proof General keywords specification is now part of the
  3666 Isabelle distribution (see etc/isar-keywords.el);
  3667 
  3668 * system: support for persistent Proof General sessions (refrain from
  3669 outdating all loaded theories on startup); user may create writable
  3670 logic images like this: ``isabelle -q HOL Test'';
  3671 
  3672 * system: smart selection of Isabelle process versus Isabelle
  3673 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3674 run both "isabelle" and "Isabelle" even if file names are badly
  3675 damaged (executable inspects the case of the first letter of its own
  3676 name); added separate "isabelle-process" and "isabelle-interface";
  3677 
  3678 * system: refrain from any attempt at filtering input streams; no
  3679 longer support ``8bit'' encoding of old isabelle font, instead proper
  3680 iso-latin characters may now be used; the related isatools
  3681 "symbolinput" and "nonascii" have disappeared as well;
  3682 
  3683 * system: removed old "xterm" interface (the print modes "xterm" and
  3684 "xterm_color" are still available for direct use in a suitable
  3685 terminal);
  3686 
  3687 
  3688 
  3689 New in Isabelle99-2 (February 2001)
  3690 -----------------------------------
  3691 
  3692 *** Overview of INCOMPATIBILITIES ***
  3693 
  3694 * HOL: please note that theories in the Library and elsewhere often use the
  3695 new-style (Isar) format; to refer to their theorems in an ML script you must
  3696 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3697 
  3698 * HOL: inductive package no longer splits induction rule aggressively,
  3699 but only as far as specified by the introductions given; the old
  3700 format may be recovered via ML function complete_split_rule or attribute
  3701 'split_rule (complete)';
  3702 
  3703 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3704 gfp_Tarski to gfp_unfold;
  3705 
  3706 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3707 
  3708 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3709 relation); infix "^^" has been renamed "``"; infix "``" has been
  3710 renamed "`"; "univalent" has been renamed "single_valued";
  3711 
  3712 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3713 operation;
  3714 
  3715 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3716 
  3717 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3718 
  3719 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3720 consequence, it is no longer monotonic wrt. the local goal context
  3721 (which is now passed through the inductive cases);
  3722 
  3723 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3724 \<gg> to \<ggreater>;
  3725 
  3726 
  3727 *** Document preparation ***
  3728 
  3729 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3730 available: are "it" for near math-mode best-style output, "sl" for
  3731 slanted text style, and "tt" for plain type-writer; if no
  3732 \isabellestyle command is given, output is according to slanted
  3733 type-writer);
  3734 
  3735 * support sub/super scripts (for single symbols only), input syntax is
  3736 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3737 
  3738 * some more standard symbols; see Appendix A of the system manual for
  3739 the complete list of symbols defined in isabellesym.sty;
  3740 
  3741 * improved isabelle style files; more abstract symbol implementation
  3742 (should now use \isamath{...} and \isatext{...} in custom symbol
  3743 definitions);
  3744 
  3745 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3746 state; Note that presentation of goal states does not conform to
  3747 actual human-readable proof documents.  Please do not include goal
  3748 states into document output unless you really know what you are doing!
  3749 
  3750 * proper indentation of antiquoted output with proportional LaTeX
  3751 fonts;
  3752 
  3753 * no_document ML operator temporarily disables LaTeX document
  3754 generation;
  3755 
  3756 * isatool unsymbolize tunes sources for plain ASCII communication;
  3757 
  3758 
  3759 *** Isar ***
  3760 
  3761 * Pure: Isar now suffers initial goal statements to contain unbound
  3762 schematic variables (this does not conform to actual readable proof
  3763 documents, due to unpredictable outcome and non-compositional proof
  3764 checking); users who know what they are doing may use schematic goals
  3765 for Prolog-style synthesis of proven results;
  3766 
  3767 * Pure: assumption method (an implicit finishing) now handles actual
  3768 rules as well;
  3769 
  3770 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3771 initial goal, declare "that" only as Pure intro (only for single
  3772 steps); the "that" rule assumption may now be involved in implicit
  3773 finishing, thus ".." becomes a feasible for trivial obtains;
  3774 
  3775 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3776 instance proofs may be performed by "..";
  3777 
  3778 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3779 statements as well;
  3780 
  3781 * Pure: more robust selection of calculational rules;
  3782 
  3783 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3784 rule (as well as the assumption rule);
  3785 
  3786 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3787 lemmas, using the graph browser tool;
  3788 
  3789 * Pure: predict failure of "show" in interactive mode;
  3790 
  3791 * Pure: 'thms_containing' now takes actual terms as arguments;
  3792 
  3793 * HOL: improved method 'induct' --- now handles non-atomic goals
  3794 (potential INCOMPATIBILITY); tuned error handling;
  3795 
  3796 * HOL: cases and induct rules now provide explicit hints about the
  3797 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3798 any remaining facts are inserted into the goal verbatim;
  3799 
  3800 * HOL: local contexts (aka cases) may now contain term bindings as
  3801 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3802 the result to be shown in each case;
  3803 
  3804 * HOL: added 'recdef_tc' command;
  3805 
  3806 * isatool convert assists in eliminating legacy ML scripts;
  3807 
  3808 
  3809 *** HOL ***
  3810 
  3811 * HOL/Library: a collection of generic theories to be used together
  3812 with main HOL; the theory loader path already includes this directory
  3813 by default; the following existing theories have been moved here:
  3814 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3815 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3816 
  3817 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3818 modelling and verification task performed in Isabelle/HOL +
  3819 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3820 
  3821 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3822 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3823 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3824 'domain', this makes the theory consistent with mathematical
  3825 literature;
  3826 
  3827 * HOL basics: added overloaded operations "inverse" and "divide"
  3828 (infix "/"), syntax for generic "abs" operation, generic summation
  3829 operator \<Sum>;
  3830 
  3831 * HOL/typedef: simplified package, provide more useful rules (see also
  3832 HOL/subset.thy);
  3833 
  3834 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3835 now expressed as a proper nested rule (old-style tactic scripts may
  3836 require atomize_strip_tac to cope with non-atomic premises);
  3837 
  3838 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3839 to "split_conv" (old name still available for compatibility);
  3840 
  3841 * HOL: improved concrete syntax for strings (e.g. allows translation
  3842 rules with string literals);
  3843 
  3844 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3845  and Fleuriot's mechanization of analysis, including the transcendental
  3846  functions for the reals;
  3847 
  3848 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3849 
  3850 
  3851 *** CTT ***
  3852 
  3853 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3854 "lam" is displayed as TWO lambda-symbols
  3855 
  3856 * CTT: theory Main now available, containing everything (that is, Bool
  3857 and Arith);
  3858 
  3859 
  3860 *** General ***
  3861 
  3862 * Pure: the Simplifier has been implemented properly as a derived rule
  3863 outside of the actual kernel (at last!); the overall performance
  3864 penalty in practical applications is about 50%, while reliability of
  3865 the Isabelle inference kernel has been greatly improved;
  3866 
  3867 * print modes "brackets" and "no_brackets" control output of nested =>
  3868 (types) and ==> (props); the default behaviour is "brackets";
  3869 
  3870 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3871 as assumptions as well;
  3872 
  3873 * system: support Poly/ML 4.0;
  3874 
  3875 * system: isatool install handles KDE version 1 or 2;
  3876 
  3877 
  3878 
  3879 New in Isabelle99-1 (October 2000)
  3880 ----------------------------------
  3881 
  3882 *** Overview of INCOMPATIBILITIES ***
  3883 
  3884 * HOL: simplification of natural numbers is much changed; to partly
  3885 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3886 issue the following ML commands:
  3887 
  3888   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3889   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3890 
  3891 * HOL: simplification no longer dives into case-expressions; this is
  3892 controlled by "t.weak_case_cong" for each datatype t;
  3893 
  3894 * HOL: nat_less_induct renamed to less_induct;
  3895 
  3896 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3897 fixsome to patch .thy and .ML sources automatically;
  3898 
  3899   select_equality  -> some_equality
  3900   select_eq_Ex     -> some_eq_ex
  3901   selectI2EX       -> someI2_ex
  3902   selectI2         -> someI2
  3903   selectI          -> someI
  3904   select1_equality -> some1_equality
  3905   Eps_sym_eq       -> some_sym_eq_trivial
  3906   Eps_eq           -> some_eq_trivial
  3907 
  3908 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3909 
  3910 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3911 instead);
  3912 
  3913 * HOL: the recursion equations generated by 'recdef' are now called
  3914 f.simps instead of f.rules;
  3915 
  3916 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3917 
  3918 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3919 sometimes be needed;
  3920 
  3921 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3922 
  3923 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3924 
  3925 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3926 product is now "<*>" instead of "Times"; the lexicographic product is
  3927 now "<*lex*>" instead of "**";
  3928 
  3929 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3930 of main HOL, but was unused); better use HOL's datatype package;
  3931 
  3932 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3933 the old syntax may be recovered as follows:
  3934 
  3935   syntax (symbols)
  3936     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3937       (infixl "\\<oplus>" 100)
  3938 
  3939 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3940 
  3941 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3942 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3943 internally;
  3944 
  3945 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3946 changed from A/r to A//r;
  3947 
  3948 * ZF: new treatment of arithmetic (nat & int) may break some old
  3949 proofs;
  3950 
  3951 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3952 rulify -> rule_format, elimify -> elim_format, ...);
  3953 
  3954 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3955 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3956 should have to change intro!! to intro? only); replaced "delrule" by
  3957 "rule del";
  3958 
  3959 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3960 
  3961 * Provers: strengthened force_tac by using new first_best_tac;
  3962 
  3963 * LaTeX document preparation: several changes of isabelle.sty (see
  3964 lib/texinputs);
  3965 
  3966 
  3967 *** Document preparation ***
  3968 
  3969 * formal comments (text blocks etc.) in new-style theories may now
  3970 contain antiquotations of thm/prop/term/typ/text to be presented
  3971 according to latex print mode; concrete syntax is like this:
  3972 @{term[show_types] "f(x) = a + x"};
  3973 
  3974 * isatool mkdir provides easy setup of Isabelle session directories,
  3975 including proper document sources;
  3976 
  3977 * generated LaTeX sources are now deleted after successful run
  3978 (isatool document -c); may retain a copy somewhere else via -D option
  3979 of isatool usedir;
  3980 
  3981 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3982 style files, achieving self-contained LaTeX sources and simplifying
  3983 LaTeX debugging;
  3984 
  3985 * old-style theories now produce (crude) LaTeX output as well;
  3986 
  3987 * browser info session directories are now self-contained (may be put
  3988 on WWW server seperately); improved graphs of nested sessions; removed
  3989 graph for 'all sessions';
  3990 
  3991 * several improvements in isabelle style files; \isabellestyle{it}
  3992 produces fake math mode output; \isamarkupheader is now \section by
  3993 default; see lib/texinputs/isabelle.sty etc.;
  3994 
  3995 
  3996 *** Isar ***
  3997 
  3998 * Isar/Pure: local results and corresponding term bindings are now
  3999 subject to Hindley-Milner polymorphism (similar to ML); this
  4000 accommodates incremental type-inference very nicely;
  4001 
  4002 * Isar/Pure: new derived language element 'obtain' supports
  4003 generalized existence reasoning;
  4004 
  4005 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4006 support accumulation of results, without applying any rules yet;
  4007 useful to collect intermediate results without explicit name
  4008 references, and for use with transitivity rules with more than 2
  4009 premises;
  4010 
  4011 * Isar/Pure: scalable support for case-analysis type proofs: new
  4012 'case' language element refers to local contexts symbolically, as
  4013 produced by certain proof methods; internally, case names are attached
  4014 to theorems as "tags";
  4015 
  4016 * Isar/Pure: theory command 'hide' removes declarations from
  4017 class/type/const name spaces;
  4018 
  4019 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4020 indicate potential overloading;
  4021 
  4022 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4023 
  4024 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4025 "{a,b,c}" instead of {a,b,c};
  4026 
  4027 * Isar/Pure now provides its own version of intro/elim/dest
  4028 attributes; useful for building new logics, but beware of confusion
  4029 with the version in Provers/classical;
  4030 
  4031 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4032 case name 'antecedent';
  4033 
  4034 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4035 to the current context is now done automatically);
  4036 
  4037 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4038 for definining proof methods in ML;
  4039 
  4040 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4041 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4042 most cases, one should have to change intro!! to intro? only);
  4043 replaced "delrule" by "rule del";
  4044 
  4045 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4046 'symmetric' attribute (the latter supercedes [RS sym]);
  4047 
  4048 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4049 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4050 well (including splits);
  4051 
  4052 * Isar/Provers: Simplifier and Classical methods now support all kind
  4053 of modifiers used in the past, including 'cong', 'iff', etc.
  4054 
  4055 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4056 of Simplifier and Classical reasoner);
  4057 
  4058 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4059 now support named cases; major packages (inductive, datatype, primrec,
  4060 recdef) support case names and properly name parameters;
  4061 
  4062 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4063 monotonicity conditions are extracted to be proven at end of
  4064 calculations;
  4065 
  4066 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4067 method anyway;
  4068 
  4069 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4070 split_if split_if_asm; datatype package provides theorems foo.splits =
  4071 foo.split foo.split_asm for each datatype;
  4072 
  4073 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4074 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4075 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4076 use "(cases (simplified))" method in proper proof texts);
  4077 
  4078 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4079 
  4080 * Isar: names of theorems etc. may be natural numbers as well;
  4081 
  4082 * Isar: 'pr' command: optional arguments for goals_limit and
  4083 ProofContext.prems_limit; no longer prints theory contexts, but only
  4084 proof states;
  4085 
  4086 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4087 additional print modes to be specified; e.g. "pr(latex)" will print
  4088 proof state according to the Isabelle LaTeX style;
  4089 
  4090 * Isar: improved support for emulating tactic scripts, including proof
  4091 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4092 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4093 (for HOL datatypes);
  4094 
  4095 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4096 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4097 'proof method scripts' have to be in depth-first order;
  4098 
  4099 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4100 
  4101 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4102 should instead use individual commands for printing items
  4103 (print_commands, print_methods etc.);
  4104 
  4105 * Isar: added 'nothing' --- the empty list of theorems;
  4106 
  4107 
  4108 *** HOL ***
  4109 
  4110 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4111 corresponding virtual machine and a specification of its bytecode
  4112 verifier and a lightweight bytecode verifier, including proofs of
  4113 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4114 Cornelia Pusch (see also the homepage of project Bali at
  4115 http://isabelle.in.tum.de/Bali/);
  4116 
  4117 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4118 Clemens Ballarin;
  4119 
  4120 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4121 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4122 Rasmussen;
  4123 
  4124 * HOL/Lattice: fundamental concepts of lattice theory and order
  4125 structures, including duals, properties of bounds versus algebraic
  4126 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4127 Theorem for complete lattices etc.; may also serve as a demonstration
  4128 for abstract algebraic reasoning using axiomatic type classes, and
  4129 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4130 
  4131 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4132 von Oheimb;
  4133 
  4134 * HOL/IMPP: extension of IMP with local variables and mutually
  4135 recursive procedures, by David von Oheimb;
  4136 
  4137 * HOL/Lambda: converted into new-style theory and document;
  4138 
  4139 * HOL/ex/Multiquote: example of multiple nested quotations and
  4140 anti-quotations -- basically a generalized version of de-Bruijn
  4141 representation; very useful in avoiding lifting of operations;
  4142 
  4143 * HOL/record: added general record equality rule to simpset; fixed
  4144 select-update simplification procedure to handle extended records as
  4145 well; admit "r" as field name;
  4146 
  4147 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4148 other numeric types and also as the identity of groups, rings, etc.;
  4149 
  4150 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4151 Types nat and int belong to this axclass;
  4152 
  4153 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4154    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4155    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4156   two terms #m*u and #n*u are replaced by #(m+n)*u
  4157     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4158   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4159     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4160 
  4161 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4162 powerful prover for predicate logic but knows nothing of clasets; see
  4163 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4164 
  4165 * HOL: new version of "case_tac" subsumes both boolean case split and
  4166 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4167 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4168 
  4169 * HOL: simplification no longer dives into case-expressions: only the
  4170 selector expression is simplified, but not the remaining arms; to
  4171 enable full simplification of case-expressions for datatype t, you may
  4172 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4173 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4174 
  4175 * HOL/recdef: the recursion equations generated by 'recdef' for
  4176 function 'f' are now called f.simps instead of f.rules; if all
  4177 termination conditions are proved automatically, these simplification
  4178 rules are added to the simpset, as in primrec; rules may be named
  4179 individually as well, resulting in a separate list of theorems for
  4180 each equation;
  4181 
  4182 * HOL/While is a new theory that provides a while-combinator. It
  4183 permits the definition of tail-recursive functions without the
  4184 provision of a termination measure. The latter is necessary once the
  4185 invariant proof rule for while is applied.
  4186 
  4187 * HOL: new (overloaded) notation for the set of elements below/above
  4188 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4189 
  4190 * HOL: theorems impI, allI, ballI bound as "strip";
  4191 
  4192 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4193 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4194 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4195 
  4196 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4197 
  4198 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4199 main HOL, but was unused);
  4200 
  4201 * HOL: fewer consts declared as global (e.g. have to refer to
  4202 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4203 
  4204 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4205 in case of overlap with user translations (e.g. judgements over
  4206 tuples); (note that the underlying logical represenation is still
  4207 bogus);
  4208 
  4209 
  4210 *** ZF ***
  4211 
  4212 * ZF: simplification automatically cancels common terms in arithmetic
  4213 expressions over nat and int;
  4214 
  4215 * ZF: new treatment of nat to minimize type-checking: all operators
  4216 coerce their operands to a natural number using the function natify,
  4217 making the algebraic laws unconditional;
  4218 
  4219 * ZF: as above, for int: operators coerce their operands to an integer
  4220 using the function intify;
  4221 
  4222 * ZF: the integer library now contains many of the usual laws for the
  4223 orderings, including $<=, and monotonicity laws for $+ and $*;
  4224 
  4225 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4226 simplification;
  4227 
  4228 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4229 to the simplifier and classical reasoner simultaneously;
  4230 
  4231 
  4232 *** General ***
  4233 
  4234 * Provers: blast_tac now handles actual object-logic rules as
  4235 assumptions; note that auto_tac uses blast_tac internally as well;
  4236 
  4237 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4238 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4239 
  4240 * Provers: delrules now handles destruct rules as well (no longer need
  4241 explicit make_elim);
  4242 
  4243 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4244   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4245 use instead the strong form,
  4246   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4247 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4248 from destruct-rules;
  4249 
  4250 * Provers: Simplifier.easy_setup provides a fast path to basic
  4251 Simplifier setup for new object-logics;
  4252 
  4253 * Pure: AST translation rules no longer require constant head on LHS;
  4254 
  4255 * Pure: improved name spaces: ambiguous output is qualified; support
  4256 for hiding of names;
  4257 
  4258 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4259 XSYMBOL_HOME; no longer need to do manual configuration in most
  4260 situations;
  4261 
  4262 * system: compression of ML heaps images may now be controlled via -c
  4263 option of isabelle and isatool usedir (currently only observed by
  4264 Poly/ML);
  4265 
  4266 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4267 useful for remote X11);
  4268 
  4269 * system: provide TAGS file for Isabelle sources;
  4270 
  4271 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4272 order;
  4273 
  4274 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4275 timing flag supersedes proof_timing and Toplevel.trace;
  4276 
  4277 * ML: new combinators |>> and |>>> for incremental transformations
  4278 with secondary results (e.g. certain theory extensions):
  4279 
  4280 * ML: PureThy.add_defs gets additional argument to indicate potential
  4281 overloading (usually false);
  4282 
  4283 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4284 results;
  4285 
  4286 
  4287 
  4288 New in Isabelle99 (October 1999)
  4289 --------------------------------
  4290 
  4291 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4292 
  4293 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4294 are no longer simplified.  (This allows the simplifier to unfold recursive
  4295 functional programs.)  To restore the old behaviour, declare
  4296 
  4297     Delcongs [if_weak_cong];
  4298 
  4299 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4300 complement;
  4301 
  4302 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4303 
  4304 * HOL/datatype: mutual_induct_tac no longer exists --
  4305   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4306 
  4307 * HOL/typedef: fixed type inference for representing set; type
  4308 arguments now have to occur explicitly on the rhs as type constraints;
  4309 
  4310 * ZF: The con_defs part of an inductive definition may no longer refer
  4311 to constants declared in the same theory;
  4312 
  4313 * HOL, ZF: the function mk_cases, generated by the inductive
  4314 definition package, has lost an argument.  To simplify its result, it
  4315 uses the default simpset instead of a supplied list of theorems.
  4316 
  4317 * HOL/List: the constructors of type list are now Nil and Cons;
  4318 
  4319 * Simplifier: the type of the infix ML functions
  4320         setSSolver addSSolver setSolver addSolver
  4321 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4322 for packaging solvers. A solver is created via
  4323         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4324 where the string argument is only a comment.
  4325 
  4326 
  4327 *** Proof tools ***
  4328 
  4329 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4330 decision procedure for linear arithmetic. Currently it is used for
  4331 types `nat', `int', and `real' in HOL (see below); it can, should and
  4332 will be instantiated for other types and logics as well.
  4333 
  4334 * The simplifier now accepts rewrite rules with flexible heads, eg
  4335      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4336   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4337   matching.
  4338 
  4339 
  4340 *** General ***
  4341 
  4342 * New Isabelle/Isar subsystem provides an alternative to traditional
  4343 tactical theorem proving; together with the ProofGeneral/isar user
  4344 interface it offers an interactive environment for developing human
  4345 readable proof documents (Isar == Intelligible semi-automated
  4346 reasoning); for further information see isatool doc isar-ref,
  4347 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4348 
  4349 * improved and simplified presentation of theories: better HTML markup
  4350 (including colors), graph views in several sizes; isatool usedir now
  4351 provides a proper interface for user theories (via -P option); actual
  4352 document preparation based on (PDF)LaTeX is available as well (for
  4353 new-style theories only); see isatool doc system for more information;
  4354 
  4355 * native support for Proof General, both for classic Isabelle and
  4356 Isabelle/Isar;
  4357 
  4358 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4359 using the graph browser tool;
  4360 
  4361 * Isabelle manuals now also available as PDF;
  4362 
  4363 * theory loader rewritten from scratch (may not be fully
  4364 bug-compatible); old loadpath variable has been replaced by show_path,
  4365 add_path, del_path, reset_path functions; new operations such as
  4366 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4367 isatool doc ref);
  4368 
  4369 * improved isatool install: option -k creates KDE application icon,
  4370 option -p DIR installs standalone binaries;
  4371 
  4372 * added ML_PLATFORM setting (useful for cross-platform installations);
  4373 more robust handling of platform specific ML images for SML/NJ;
  4374 
  4375 * the settings environment is now statically scoped, i.e. it is never
  4376 created again in sub-processes invoked from isabelle, isatool, or
  4377 Isabelle;
  4378 
  4379 * path element specification '~~' refers to '$ISABELLE_HOME';
  4380 
  4381 * in locales, the "assumes" and "defines" parts may be omitted if
  4382 empty;
  4383 
  4384 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4385 long arrows);
  4386 
  4387 * new print_mode "HTML";
  4388 
  4389 * new flag show_tags controls display of tags of theorems (which are
  4390 basically just comments that may be attached by some tools);
  4391 
  4392 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4393 mode and goal output format:
  4394 
  4395 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4396 244c244
  4397 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4398 ---
  4399 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4400 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4401 181c181
  4402 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4403 ---
  4404 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4405 
  4406 * function bind_thms stores lists of theorems (cf. bind_thm);
  4407 
  4408 * new shorthand tactics ftac, eatac, datac, fatac;
  4409 
  4410 * qed (and friends) now accept "" as result name; in that case the
  4411 theorem is not stored, but proper checks and presentation of the
  4412 result still apply;
  4413 
  4414 * theorem database now also indexes constants "Trueprop", "all",
  4415 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4416 
  4417 
  4418 *** HOL ***
  4419 
  4420 ** HOL arithmetic **
  4421 
  4422 * There are now decision procedures for linear arithmetic over nat and
  4423 int:
  4424 
  4425 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4426 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4427 are treated as atomic; subformulae not involving type `nat' or `int'
  4428 are ignored; quantified subformulae are ignored unless they are
  4429 positive universal or negative existential. The tactic has to be
  4430 invoked by hand and can be a little bit slow. In particular, the
  4431 running time is exponential in the number of occurrences of `min' and
  4432 `max', and `-' on `nat'.
  4433 
  4434 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4435 (negated) (in)equalities among the premises and the conclusion into
  4436 account (i.e. no compound formulae) and does not know about `min' and
  4437 `max', and `-' on `nat'. It is fast and is used automatically by the
  4438 simplifier.
  4439 
  4440 NB: At the moment, these decision procedures do not cope with mixed
  4441 nat/int formulae where the two parts interact, such as `m < n ==>
  4442 int(m) < int(n)'.
  4443 
  4444 * HOL/Numeral provides a generic theory of numerals (encoded
  4445 efficiently as bit strings); setup for types nat/int/real is in place;
  4446 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4447 int, existing theories and proof scripts may require a few additional
  4448 type constraints;
  4449 
  4450 * integer division and remainder can now be performed on constant
  4451 arguments;
  4452 
  4453 * many properties of integer multiplication, division and remainder
  4454 are now available;
  4455 
  4456 * An interface to the Stanford Validity Checker (SVC) is available through the
  4457 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4458 are proved automatically.  SVC must be installed separately, and its results
  4459 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4460 invocation of the underlying oracle).  For SVC see
  4461   http://verify.stanford.edu/SVC
  4462 
  4463 * IsaMakefile: the HOL-Real target now builds an actual image;
  4464 
  4465 
  4466 ** HOL misc **
  4467 
  4468 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4469 (in Isabelle/Isar) -- by Gertrud Bauer;
  4470 
  4471 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4472 analysis for assembly languages with subtypes;
  4473 
  4474 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4475 -- avoids syntactic ambiguities and treats state, transition, and
  4476 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4477 changed syntax and (many) tactics;
  4478 
  4479 * HOL/inductive: Now also handles more general introduction rules such
  4480   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4481   theorems are now maintained within the theory (maintained via the
  4482   "mono" attribute);
  4483 
  4484 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4485   (using function types) such as
  4486 
  4487   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4488 
  4489 * HOL/record: record_simproc (part of the default simpset) takes care
  4490 of selectors applied to updated records; record_split_tac is no longer
  4491 part of the default claset; update_defs may now be removed from the
  4492 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4493 
  4494   claset_ref () := claset() addSWrapper record_split_wrapper;
  4495   Delsimprocs [record_simproc]
  4496 
  4497 * HOL/typedef: fixed type inference for representing set; type
  4498 arguments now have to occur explicitly on the rhs as type constraints;
  4499 
  4500 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4501 names rather than an ML expression;
  4502 
  4503 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4504 supplied later.  Program schemes can be defined, such as
  4505     "While B C s = (if B s then While B C (C s) else s)"
  4506 where the well-founded relation can be chosen after B and C have been given.
  4507 
  4508 * HOL/List: the constructors of type list are now Nil and Cons;
  4509 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4510 course, ML tools referring to List.list.op # etc. have to be adapted;
  4511 
  4512 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4513 disabled by default; run isabelle with option -m HOL to get back to
  4514 the original Gordon/HOL-style output;
  4515 
  4516 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4517 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4518 
  4519 * HOL basic syntax simplified (more orthogonal): all variants of
  4520 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4521 Eps operator is provided as well: "SOME x. P[x]";
  4522 
  4523 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4524 
  4525 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4526 thus available for user theories;
  4527 
  4528 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4529 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4530 time;
  4531 
  4532 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4533 several times and then mp;
  4534 
  4535 
  4536 *** LK ***
  4537 
  4538 * the notation <<...>> is now available as a notation for sequences of
  4539 formulas;
  4540 
  4541 * the simplifier is now installed
  4542 
  4543 * the axiom system has been generalized (thanks to Soren Heilmann)
  4544 
  4545 * the classical reasoner now has a default rule database
  4546 
  4547 
  4548 *** ZF ***
  4549 
  4550 * new primrec section allows primitive recursive functions to be given
  4551 directly (as in HOL) over datatypes and the natural numbers;
  4552 
  4553 * new tactics induct_tac and exhaust_tac for induction (or case
  4554 analysis) over datatypes and the natural numbers;
  4555 
  4556 * the datatype declaration of type T now defines the recursor T_rec;
  4557 
  4558 * simplification automatically does freeness reasoning for datatype
  4559 constructors;
  4560 
  4561 * automatic type-inference, with AddTCs command to insert new
  4562 type-checking rules;
  4563 
  4564 * datatype introduction rules are now added as Safe Introduction rules
  4565 to the claset;
  4566 
  4567 * the syntax "if P then x else y" is now available in addition to
  4568 if(P,x,y);
  4569 
  4570 
  4571 *** Internal programming interfaces ***
  4572 
  4573 * tuned simplifier trace output; new flag debug_simp;
  4574 
  4575 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4576 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4577 
  4578 * AxClass.axclass_tac lost the theory argument;
  4579 
  4580 * tuned current_goals_markers semantics: begin / end goal avoids
  4581 printing empty lines;
  4582 
  4583 * removed prs and prs_fn hook, which was broken because it did not
  4584 include \n in its semantics, forcing writeln to add one
  4585 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4586 string -> unit if you really want to output text without newline;
  4587 
  4588 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4589 plain output, interface builders may have to enable 'isabelle_font'
  4590 mode to get Isabelle font glyphs as before;
  4591 
  4592 * refined token_translation interface; INCOMPATIBILITY: output length
  4593 now of type real instead of int;
  4594 
  4595 * theory loader actions may be traced via new ThyInfo.add_hook
  4596 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4597 your own database of information attached to *whole* theories -- as
  4598 opposed to intra-theory data slots offered via TheoryDataFun;
  4599 
  4600 * proper handling of dangling sort hypotheses (at last!);
  4601 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4602 extra sort hypotheses that can be witnessed from the type signature;
  4603 the force_strip_shyps flag is gone, any remaining shyps are simply
  4604 left in the theorem (with a warning issued by strip_shyps_warning);
  4605 
  4606 
  4607 
  4608 New in Isabelle98-1 (October 1998)
  4609 ----------------------------------
  4610 
  4611 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4612 
  4613 * several changes of automated proof tools;
  4614 
  4615 * HOL: major changes to the inductive and datatype packages, including
  4616 some minor incompatibilities of theory syntax;
  4617 
  4618 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4619 called `inj_on';
  4620 
  4621 * HOL: removed duplicate thms in Arith:
  4622   less_imp_add_less  should be replaced by  trans_less_add1
  4623   le_imp_add_le      should be replaced by  trans_le_add1
  4624 
  4625 * HOL: unary minus is now overloaded (new type constraints may be
  4626 required);
  4627 
  4628 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4629 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4630 now taken as an integer constant.
  4631 
  4632 * Pure: ML function 'theory_of' renamed to 'theory';
  4633 
  4634 
  4635 *** Proof tools ***
  4636 
  4637 * Simplifier:
  4638   1. Asm_full_simp_tac is now more aggressive.
  4639      1. It will sometimes reorient premises if that increases their power to
  4640         simplify.
  4641      2. It does no longer proceed strictly from left to right but may also
  4642         rotate premises to achieve further simplification.
  4643      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4644      old Asm_full_simp_tac in that it does not rotate premises.
  4645   2. The simplifier now knows a little bit about nat-arithmetic.
  4646 
  4647 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4648 allows for selected deletion of wrappers, by introduction of names for
  4649 wrapper functionals.  This implies that addbefore, addSbefore,
  4650 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4651 and that adding two tactics with the same name overwrites the first
  4652 one (emitting a warning).
  4653   type wrapper = (int -> tactic) -> (int -> tactic)
  4654   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4655   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4656   delWrapper, delSWrapper: claset *  string            -> claset
  4657   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4658 
  4659 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4660 semantics; addbefore now affects only the unsafe part of step_tac
  4661 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4662 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4663 by Force_tac;
  4664 
  4665 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4666 compWrapper; added safe wrapper (and access functions for it);
  4667 
  4668 * HOL/split_all_tac is now much faster and fails if there is nothing
  4669 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4670 and the names of the automatically generated variables have changed.
  4671 split_all_tac has moved within claset() from unsafe wrappers to safe
  4672 wrappers, which means that !!-bound variables are split much more
  4673 aggressively, and safe_tac and clarify_tac now split such variables.
  4674 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4675 Note: the same holds for record_split_tac, which does the job of
  4676 split_all_tac for record fields.
  4677 
  4678 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4679 permanently to the default simpset using Addsplits just like
  4680 Addsimps. They can be removed via Delsplits just like
  4681 Delsimps. Lower-case versions are also available.
  4682 
  4683 * HOL/Simplifier: The rule split_if is now part of the default
  4684 simpset. This means that the simplifier will eliminate all occurrences
  4685 of if-then-else in the conclusion of a goal. To prevent this, you can
  4686 either remove split_if completely from the default simpset by
  4687 `Delsplits [split_if]' or remove it in a specific call of the
  4688 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4689 other case splitting rules to/from the default simpset: every datatype
  4690 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4691 t is the name of the datatype).
  4692 
  4693 * Classical reasoner / Simplifier combination: new force_tac (and
  4694 derivatives Force_tac, force) combines rewriting and classical
  4695 reasoning (and whatever other tools) similarly to auto_tac, but is
  4696 aimed to solve the given subgoal completely.
  4697 
  4698 
  4699 *** General ***
  4700 
  4701 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4702 and `goalw': the theory is no longer needed as an explicit argument -
  4703 the current theory context is used; assumptions are no longer returned
  4704 at the ML-level unless one of them starts with ==> or !!; it is
  4705 recommended to convert to these new commands using isatool fixgoal
  4706 (backup your sources first!);
  4707 
  4708 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4709 the current theory context, and 'theory' to lookup stored theories;
  4710 
  4711 * new theory section 'locale' for declaring constants, assumptions and
  4712 definitions that have local scope;
  4713 
  4714 * new theory section 'nonterminals' for purely syntactic types;
  4715 
  4716 * new theory section 'setup' for generic ML setup functions
  4717 (e.g. package initialization);
  4718 
  4719 * the distribution now includes Isabelle icons: see
  4720 lib/logo/isabelle-{small,tiny}.xpm;
  4721 
  4722 * isatool install - install binaries with absolute references to
  4723 ISABELLE_HOME/bin;
  4724 
  4725 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4726 
  4727 * print mode 'emacs' reserved for Isamode;
  4728 
  4729 * support multiple print (ast) translations per constant name;
  4730 
  4731 * theorems involving oracles are now printed with a suffixed [!];
  4732 
  4733 
  4734 *** HOL ***
  4735 
  4736 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4737 
  4738 * HOL/inductive package reorganized and improved: now supports mutual
  4739 definitions such as
  4740 
  4741   inductive EVEN ODD
  4742     intrs
  4743       null "0 : EVEN"
  4744       oddI "n : EVEN ==> Suc n : ODD"
  4745       evenI "n : ODD ==> Suc n : EVEN"
  4746 
  4747 new theorem list "elims" contains an elimination rule for each of the
  4748 recursive sets; inductive definitions now handle disjunctive premises
  4749 correctly (also ZF);
  4750 
  4751 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4752 "mutual_induct" no longer exists - the induction rule is always
  4753 contained in "induct";
  4754 
  4755 
  4756 * HOL/datatype package re-implemented and greatly improved: now
  4757 supports mutually recursive datatypes such as
  4758 
  4759   datatype
  4760     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4761             | SUM ('a aexp) ('a aexp)
  4762             | DIFF ('a aexp) ('a aexp)
  4763             | NUM 'a
  4764   and
  4765     'a bexp = LESS ('a aexp) ('a aexp)
  4766             | AND ('a bexp) ('a bexp)
  4767             | OR ('a bexp) ('a bexp)
  4768 
  4769 as well as indirectly recursive datatypes such as
  4770 
  4771   datatype
  4772     ('a, 'b) term = Var 'a
  4773                   | App 'b ((('a, 'b) term) list)
  4774 
  4775 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4776 induction on mutually / indirectly recursive datatypes.
  4777 
  4778 Primrec equations are now stored in theory and can be accessed via
  4779 <function_name>.simps.
  4780 
  4781 INCOMPATIBILITIES:
  4782 
  4783   - Theories using datatypes must now have theory Datatype as an
  4784     ancestor.
  4785   - The specific <typename>.induct_tac no longer exists - use the
  4786     generic induct_tac instead.
  4787   - natE has been renamed to nat.exhaust - use exhaust_tac
  4788     instead of res_inst_tac ... natE. Note that the variable
  4789     names in nat.exhaust differ from the names in natE, this
  4790     may cause some "fragile" proofs to fail.
  4791   - The theorems split_<typename>_case and split_<typename>_case_asm
  4792     have been renamed to <typename>.split and <typename>.split_asm.
  4793   - Since default sorts of type variables are now handled correctly,
  4794     some datatype definitions may have to be annotated with explicit
  4795     sort constraints.
  4796   - Primrec definitions no longer require function name and type
  4797     of recursive argument.
  4798 
  4799 Consider using isatool fixdatatype to adapt your theories and proof
  4800 scripts to the new package (backup your sources first!).
  4801 
  4802 
  4803 * HOL/record package: considerably improved implementation; now
  4804 includes concrete syntax for record types, terms, updates; theorems
  4805 for surjective pairing and splitting !!-bound record variables; proof
  4806 support is as follows:
  4807 
  4808   1) standard conversions (selectors or updates applied to record
  4809 constructor terms) are part of the standard simpset;
  4810 
  4811   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4812 made part of standard simpset and claset via addIffs;
  4813 
  4814   3) a tactic for record field splitting (record_split_tac) is part of
  4815 the standard claset (addSWrapper);
  4816 
  4817 To get a better idea about these rules you may retrieve them via
  4818 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4819 the name of your record type.
  4820 
  4821 The split tactic 3) conceptually simplifies by the following rule:
  4822 
  4823   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4824 
  4825 Thus any record variable that is bound by meta-all will automatically
  4826 blow up into some record constructor term, consequently the
  4827 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4828 solve record problems automatically.
  4829 
  4830 
  4831 * reorganized the main HOL image: HOL/Integ and String loaded by
  4832 default; theory Main includes everything;
  4833 
  4834 * automatic simplification of integer sums and comparisons, using cancellation;
  4835 
  4836 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4837 
  4838 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4839 
  4840 * many new identities for unions, intersections, set difference, etc.;
  4841 
  4842 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4843 called split_if, split_split, split_sum_case and split_nat_case (to go
  4844 with add/delsplits);
  4845 
  4846 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4847 (?x::unit) = (); this is made part of the default simpset, which COULD
  4848 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4849 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4850 unit_abs_eta_conv is added in order to counter the effect of
  4851 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4852 %u.f();
  4853 
  4854 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4855 makes more sense);
  4856 
  4857 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4858   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4859   disjointness reasoning but breaking a few old proofs.
  4860 
  4861 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4862 to 'converse' from 'inverse' (for compatibility with ZF and some
  4863 literature);
  4864 
  4865 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4866 the well-founded relation;
  4867 
  4868 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4869     Compl A.  The "Compl" syntax remains available as input syntax for this
  4870     release ONLY.
  4871 
  4872 * HOL/Update: new theory of function updates:
  4873     f(a:=b) == %x. if x=a then b else f x
  4874 may also be iterated as in f(a:=b,c:=d,...);
  4875 
  4876 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4877 
  4878 * HOL/List:
  4879   - new function list_update written xs[i:=v] that updates the i-th
  4880     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4881   - new function `upt' written [i..j(] which generates the list
  4882     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4883     bound write [i..j], which is a shorthand for [i..j+1(].
  4884   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4885 
  4886 * HOL/Arith:
  4887   - removed 'pred' (predecessor) function;
  4888   - generalized some theorems about n-1;
  4889   - many new laws about "div" and "mod";
  4890   - new laws about greatest common divisors (see theory ex/Primes);
  4891 
  4892 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4893 instead of "inverse";
  4894 
  4895 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4896   of the multiset ordering;
  4897 
  4898 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4899   (not included by default);
  4900 
  4901 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4902 
  4903 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4904   programs, i.e. different program variables may have different types.
  4905 
  4906 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4907   [previously, this check worked only if the rewrite rule was unconditional]
  4908   Now rew can involve either definitions or equalities (either == or =).
  4909 
  4910 
  4911 *** ZF ***
  4912 
  4913 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4914   only the theorems proved on ZF.ML;
  4915 
  4916 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4917   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4918   disjointness reasoning but breaking a few old proofs.
  4919 
  4920 * ZF/Update: new theory of function updates
  4921     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4922   may also be iterated as in f(a:=b,c:=d,...);
  4923 
  4924 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4925 
  4926 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4927   [previously, this check worked only if the rewrite rule was unconditional]
  4928   Now rew can involve either definitions or equalities (either == or =).
  4929 
  4930 * case_tac provided for compatibility with HOL
  4931     (like the old excluded_middle_tac, but with subgoals swapped)
  4932 
  4933 
  4934 *** Internal programming interfaces ***
  4935 
  4936 * Pure: several new basic modules made available for general use, see
  4937 also src/Pure/README;
  4938 
  4939 * improved the theory data mechanism to support encapsulation (data
  4940 kind name replaced by private Object.kind, acting as authorization
  4941 key); new type-safe user interface via functor TheoryDataFun; generic
  4942 print_data function becomes basically useless;
  4943 
  4944 * removed global_names compatibility flag -- all theory declarations
  4945 are qualified by default;
  4946 
  4947 * module Pure/Syntax now offers quote / antiquote translation
  4948 functions (useful for Hoare logic etc. with implicit dependencies);
  4949 see HOL/ex/Antiquote for an example use;
  4950 
  4951 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4952 cterm -> thm;
  4953 
  4954 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4955 subgoal;
  4956 
  4957 * Display.print_goals function moved to Locale.print_goals;
  4958 
  4959 * standard print function for goals supports current_goals_markers
  4960 variable for marking begin of proof, end of proof, start of goal; the
  4961 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4962 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4963 for example;
  4964 
  4965 
  4966 
  4967 New in Isabelle98 (January 1998)
  4968 --------------------------------
  4969 
  4970 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4971 
  4972 * changed lexical syntax of terms / types: dots made part of long
  4973 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4974 
  4975 * simpset (and claset) reference variable replaced by functions
  4976 simpset / simpset_ref;
  4977 
  4978 * no longer supports theory aliases (via merge) and non-trivial
  4979 implicit merge of thms' signatures;
  4980 
  4981 * most internal names of constants changed due to qualified names;
  4982 
  4983 * changed Pure/Sequence interface (see Pure/seq.ML);
  4984 
  4985 
  4986 *** General Changes ***
  4987 
  4988 * hierachically structured name spaces (for consts, types, axms, thms
  4989 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4990 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4991 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4992 long_names for fully qualified output names; NOTE: ML programs
  4993 (special tactics, packages etc.) referring to internal names may have
  4994 to be adapted to cope with fully qualified names; in case of severe
  4995 backward campatibility problems try setting 'global_names' at compile
  4996 time to have enrything declared within a flat name space; one may also
  4997 fine tune name declarations in theories via the 'global' and 'local'
  4998 section;
  4999 
  5000 * reimplemented the implicit simpset and claset using the new anytype
  5001 data filed in signatures; references simpset:simpset ref etc. are
  5002 replaced by functions simpset:unit->simpset and
  5003 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5004 to patch your ML files accordingly;
  5005 
  5006 * HTML output now includes theory graph data for display with Java
  5007 applet or isatool browser; data generated automatically via isatool
  5008 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5009 
  5010 * defs may now be conditional; improved rewrite_goals_tac to handle
  5011 conditional equations;
  5012 
  5013 * defs now admits additional type arguments, using TYPE('a) syntax;
  5014 
  5015 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5016 creates a new theory node; implicit merge of thms' signatures is
  5017 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5018 transfer:theory->thm->thm in (rare) cases;
  5019 
  5020 * improved handling of draft signatures / theories; draft thms (and
  5021 ctyps, cterms) are automatically promoted to real ones;
  5022 
  5023 * slightly changed interfaces for oracles: admit many per theory, named
  5024 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5025 
  5026 * print_goals: optional output of const types (set show_consts and
  5027 show_types);
  5028 
  5029 * improved output of warnings (###) and errors (***);
  5030 
  5031 * subgoal_tac displays a warning if the new subgoal has type variables;
  5032 
  5033 * removed old README and Makefiles;
  5034 
  5035 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5036 
  5037 * removed obsolete init_pps and init_database;
  5038 
  5039 * deleted the obsolete tactical STATE, which was declared by
  5040     fun STATE tacfun st = tacfun st st;
  5041 
  5042 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5043 (which abbreviates $HOME);
  5044 
  5045 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5046 use isatool fixseq to adapt your ML programs (this works for fully
  5047 qualified references to the Sequence structure only!);
  5048 
  5049 * use_thy no longer requires writable current directory; it always
  5050 reloads .ML *and* .thy file, if either one is out of date;
  5051 
  5052 
  5053 *** Classical Reasoner ***
  5054 
  5055 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5056 tactics that use classical reasoning to simplify a subgoal without
  5057 splitting it into several subgoals;
  5058 
  5059 * Safe_tac: like safe_tac but uses the default claset;
  5060 
  5061 
  5062 *** Simplifier ***
  5063 
  5064 * added simplification meta rules:
  5065     (asm_)(full_)simplify: simpset -> thm -> thm;
  5066 
  5067 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5068 logics (again);
  5069 
  5070 * added prems argument to simplification procedures;
  5071 
  5072 * HOL, FOL, ZF: added infix function `addsplits':
  5073   instead of `<simpset> setloop (split_tac <thms>)'
  5074   you can simply write `<simpset> addsplits <thms>'
  5075 
  5076 
  5077 *** Syntax ***
  5078 
  5079 * TYPE('a) syntax for type reflection terms;
  5080 
  5081 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5082 
  5083 * pretty printer: changed order of mixfix annotation preference (again!);
  5084 
  5085 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5086 
  5087 
  5088 *** HOL ***
  5089 
  5090 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5091   with `addloop' of the simplifier to faciliate case splitting in premises.
  5092 
  5093 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5094 
  5095 * HOL/Auth: new protocol proofs including some for the Internet
  5096   protocol TLS;
  5097 
  5098 * HOL/Map: new theory of `maps' a la VDM;
  5099 
  5100 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5101 cancelling out common nat summands from =, <, <= (in)equalities, or
  5102 differences; simplification procedures nat_cancel_factor for
  5103 cancelling common factor from =, <, <= (in)equalities over natural
  5104 sums; nat_cancel contains both kinds of procedures, it is installed by
  5105 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5106 
  5107 * HOL/simplifier: terms of the form
  5108   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5109   are rewritten to
  5110   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5111   and those of the form
  5112   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5113   are rewritten to
  5114   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5115 
  5116 * HOL/datatype
  5117   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5118 
  5119   P(t_case f1 ... fn x) =
  5120      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5121         ...
  5122        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5123      )
  5124 
  5125   and a theorem `split_t_case_asm' of the form
  5126 
  5127   P(t_case f1 ... fn x) =
  5128     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5129         ...
  5130        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5131      )
  5132   which can be added to a simpset via `addsplits'. The existing theorems
  5133   expand_list_case and expand_option_case have been renamed to
  5134   split_list_case and split_option_case.
  5135 
  5136 * HOL/Arithmetic:
  5137   - `pred n' is automatically converted to `n-1'.
  5138     Users are strongly encouraged not to use `pred' any longer,
  5139     because it will disappear altogether at some point.
  5140   - Users are strongly encouraged to write "0 < n" rather than
  5141     "n ~= 0". Theorems and proof tools have been modified towards this
  5142     `standard'.
  5143 
  5144 * HOL/Lists:
  5145   the function "set_of_list" has been renamed "set" (and its theorems too);
  5146   the function "nth" now takes its arguments in the reverse order and
  5147   has acquired the infix notation "!" as in "xs!n".
  5148 
  5149 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5150 
  5151 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5152   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5153 
  5154 * HOL/record: extensible records with schematic structural subtyping
  5155 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5156 still lacks various theorems and concrete record syntax;
  5157 
  5158 
  5159 *** HOLCF ***
  5160 
  5161 * removed "axioms" and "generated by" sections;
  5162 
  5163 * replaced "ops" section by extended "consts" section, which is capable of
  5164   handling the continuous function space "->" directly;
  5165 
  5166 * domain package:
  5167   . proves theorems immediately and stores them in the theory,
  5168   . creates hierachical name space,
  5169   . now uses normal mixfix annotations (instead of cinfix...),
  5170   . minor changes to some names and values (for consistency),
  5171   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5172   . separator between mutual domain defs: changed "," to "and",
  5173   . improved handling of sort constraints;  now they have to
  5174     appear on the left-hand side of the equations only;
  5175 
  5176 * fixed LAM <x,y,zs>.b syntax;
  5177 
  5178 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5179 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5180 
  5181 
  5182 *** FOL and ZF ***
  5183 
  5184 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5185   with `addloop' of the simplifier to faciliate case splitting in premises.
  5186 
  5187 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5188 in HOL, they strip ALL and --> from proved theorems;
  5189 
  5190 
  5191 
  5192 New in Isabelle94-8 (May 1997)
  5193 ------------------------------
  5194 
  5195 *** General Changes ***
  5196 
  5197 * new utilities to build / run / maintain Isabelle etc. (in parts
  5198 still somewhat experimental); old Makefiles etc. still functional;
  5199 
  5200 * new 'Isabelle System Manual';
  5201 
  5202 * INSTALL text, together with ./configure and ./build scripts;
  5203 
  5204 * reimplemented type inference for greater efficiency, better error
  5205 messages and clean internal interface;
  5206 
  5207 * prlim command for dealing with lots of subgoals (an easier way of
  5208 setting goals_limit);
  5209 
  5210 
  5211 *** Syntax ***
  5212 
  5213 * supports alternative (named) syntax tables (parser and pretty
  5214 printer); internal interface is provided by add_modesyntax(_i);
  5215 
  5216 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5217 be used in conjunction with the Isabelle symbol font; uses the
  5218 "symbols" syntax table;
  5219 
  5220 * added token_translation interface (may translate name tokens in
  5221 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5222 the current print_mode); IMPORTANT: user print translation functions
  5223 are responsible for marking newly introduced bounds
  5224 (Syntax.mark_boundT);
  5225 
  5226 * token translations for modes "xterm" and "xterm_color" that display
  5227 names in bold, underline etc. or colors (which requires a color
  5228 version of xterm);
  5229 
  5230 * infixes may now be declared with names independent of their syntax;
  5231 
  5232 * added typed_print_translation (like print_translation, but may
  5233 access type of constant);
  5234 
  5235 
  5236 *** Classical Reasoner ***
  5237 
  5238 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5239 some limitations.  Blast_tac...
  5240   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5241   + ignores elimination rules that don't have the correct format
  5242         (the conclusion MUST be a formula variable)
  5243   + ignores types, which can make HOL proofs fail
  5244   + rules must not require higher-order unification, e.g. apply_type in ZF
  5245     [message "Function Var's argument not a bound variable" relates to this]
  5246   + its proof strategy is more general but can actually be slower
  5247 
  5248 * substitution with equality assumptions no longer permutes other
  5249 assumptions;
  5250 
  5251 * minor changes in semantics of addafter (now called addaltern); renamed
  5252 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5253 (and access functions for it);
  5254 
  5255 * improved combination of classical reasoner and simplifier:
  5256   + functions for handling clasimpsets
  5257   + improvement of addss: now the simplifier is called _after_ the
  5258     safe steps.
  5259   + safe variant of addss called addSss: uses safe simplifications
  5260     _during_ the safe steps. It is more complete as it allows multiple
  5261     instantiations of unknowns (e.g. with slow_tac).
  5262 
  5263 *** Simplifier ***
  5264 
  5265 * added interface for simplification procedures (functions that
  5266 produce *proven* rewrite rules on the fly, depending on current
  5267 redex);
  5268 
  5269 * ordering on terms as parameter (used for ordered rewriting);
  5270 
  5271 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5272 
  5273 * the solver is now split into a safe and an unsafe part.
  5274 This should be invisible for the normal user, except that the
  5275 functions setsolver and addsolver have been renamed to setSolver and
  5276 addSolver; added safe_asm_full_simp_tac;
  5277 
  5278 
  5279 *** HOL ***
  5280 
  5281 * a generic induction tactic `induct_tac' which works for all datatypes and
  5282 also for type `nat';
  5283 
  5284 * a generic case distinction tactic `exhaust_tac' which works for all
  5285 datatypes and also for type `nat';
  5286 
  5287 * each datatype comes with a function `size';
  5288 
  5289 * patterns in case expressions allow tuple patterns as arguments to
  5290 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5291 
  5292 * primrec now also works with type nat;
  5293 
  5294 * recdef: a new declaration form, allows general recursive functions to be
  5295 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5296 
  5297 * the constant for negation has been renamed from "not" to "Not" to
  5298 harmonize with FOL, ZF, LK, etc.;
  5299 
  5300 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5301 infinite lists;
  5302 
  5303 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5304 
  5305 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5306 problems in commutative rings, using axiomatic type classes for + and *;
  5307 
  5308 * more examples in HOL/MiniML and HOL/Auth;
  5309 
  5310 * more default rewrite rules for quantifiers, union/intersection;
  5311 
  5312 * a new constant `arbitrary == @x.False';
  5313 
  5314 * HOLCF/IOA replaces old HOL/IOA;
  5315 
  5316 * HOLCF changes: derived all rules and arities
  5317   + axiomatic type classes instead of classes
  5318   + typedef instead of faking type definitions
  5319   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5320   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5321   + eliminated the types void, one, tr
  5322   + use unit lift and bool lift (with translations) instead of one and tr
  5323   + eliminated blift from Lift3.thy (use Def instead of blift)
  5324   all eliminated rules are derived as theorems --> no visible changes ;
  5325 
  5326 
  5327 *** ZF ***
  5328 
  5329 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5330 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5331 as ZF_cs addSIs [equalityI];
  5332 
  5333 
  5334 
  5335 New in Isabelle94-7 (November 96)
  5336 ---------------------------------
  5337 
  5338 * allowing negative levels (as offsets) in prlev and choplev;
  5339 
  5340 * super-linear speedup for large simplifications;
  5341 
  5342 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5343 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5344 FAIL); can suppress it using the command Delsimps (ex_simps @
  5345 all_simps); De Morgan laws are also now included, by default;
  5346 
  5347 * improved printing of ==>  :  ~:
  5348 
  5349 * new object-logic "Sequents" adds linear logic, while replacing LK
  5350 and Modal (thanks to Sara Kalvala);
  5351 
  5352 * HOL/Auth: correctness proofs for authentication protocols;
  5353 
  5354 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5355 examples on HOL/Auth);
  5356 
  5357 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5358 the rewriter and classical reasoner simultaneously;
  5359 
  5360 * function uresult no longer returns theorems in "standard" format;
  5361 regain previous version by: val uresult = standard o uresult;
  5362 
  5363 
  5364 
  5365 New in Isabelle94-6
  5366 -------------------
  5367 
  5368 * oracles -- these establish an interface between Isabelle and trusted
  5369 external reasoners, which may deliver results as theorems;
  5370 
  5371 * proof objects (in particular record all uses of oracles);
  5372 
  5373 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5374 
  5375 * "constdefs" section in theory files;
  5376 
  5377 * "primrec" section (HOL) no longer requires names;
  5378 
  5379 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5380 
  5381 
  5382 
  5383 New in Isabelle94-5
  5384 -------------------
  5385 
  5386 * reduced space requirements;
  5387 
  5388 * automatic HTML generation from theories;
  5389 
  5390 * theory files no longer require "..." (quotes) around most types;
  5391 
  5392 * new examples, including two proofs of the Church-Rosser theorem;
  5393 
  5394 * non-curried (1994) version of HOL is no longer distributed;
  5395 
  5396 
  5397 
  5398 New in Isabelle94-4
  5399 -------------------
  5400 
  5401 * greatly reduced space requirements;
  5402 
  5403 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5404 
  5405 * searchable theorem database (see the section "Retrieving theorems" on
  5406 page 8 of the Reference Manual);
  5407 
  5408 * new examples, including Grabczewski's monumental case study of the
  5409 Axiom of Choice;
  5410 
  5411 * The previous version of HOL renamed to Old_HOL;
  5412 
  5413 * The new version of HOL (previously called CHOL) uses a curried syntax
  5414 for functions.  Application looks like f a b instead of f(a,b);
  5415 
  5416 * Mutually recursive inductive definitions finally work in HOL;
  5417 
  5418 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5419 translates to the operator "split";
  5420 
  5421 
  5422 
  5423 New in Isabelle94-3
  5424 -------------------
  5425 
  5426 * new infix operator, addss, allowing the classical reasoner to
  5427 perform simplification at each step of its search.  Example:
  5428         fast_tac (cs addss ss)
  5429 
  5430 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5431 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5432 look like (a,b) instead of <a,b>;
  5433 
  5434 * PLEASE NOTE: CHOL will eventually replace HOL!
  5435 
  5436 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5437 It translates to the operator "split".  A new theory of integers is available;
  5438 
  5439 * In ZF, integer numerals now denote two's-complement binary integers.
  5440 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5441 
  5442 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5443 of the Axiom of Choice;
  5444 
  5445 
  5446 
  5447 New in Isabelle94-2
  5448 -------------------
  5449 
  5450 * Significantly faster resolution;
  5451 
  5452 * the different sections in a .thy file can now be mixed and repeated
  5453 freely;
  5454 
  5455 * Database of theorems for FOL, HOL and ZF.  New
  5456 commands including qed, qed_goal and bind_thm store theorems in the database.
  5457 
  5458 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5459 a given theory (thms_of), or find out what theory a theorem was proved in
  5460 (theory_of_thm);
  5461 
  5462 * Bugs fixed in the inductive definition and datatype packages;
  5463 
  5464 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5465 and HOL_dup_cs obsolete;
  5466 
  5467 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5468 have been removed;
  5469 
  5470 * Simpler definition of function space in ZF;
  5471 
  5472 * new results about cardinal and ordinal arithmetic in ZF;
  5473 
  5474 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5475 types;
  5476 
  5477 :mode=text:wrap=hard:maxLineLen=72:
  5478 
  5479 $Id$