NEWS
author wenzelm
Sat May 17 13:54:30 2008 +0200 (2008-05-17)
changeset 26928 ca87aff1ad2d
parent 26925 ce964f0df281
child 26955 ebbaa935eae0
permissions -rw-r--r--
structure Display: less pervasive operations;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Syntax: symbol \<chi> is now considered a letter.  Potential
    10 INCOMPATIBILITY in identifier syntax etc.
    11 
    12 * Outer syntax: string tokens may contain arbitrary character codes
    13 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
    14 "foo_bar".
    15 
    16 * Outer syntax: string tokens no longer admit escaped white space,
    17 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
    18 white space directly.
    19 
    20 * Theory loader: use_thy (and similar operations) no longer set the
    21 implicit ML context, which was occasionally hard to predict and in
    22 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
    23 provides a proper context already.
    24 
    25 * Theory loader: old-style ML proof scripts being *attached* to a thy
    26 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
    27 'use' within a theory file will do the job.
    28 
    29 * Name space merge now observes canonical order, i.e. the second space
    30 is inserted into the first one, while existing entries in the first
    31 space take precedence.  INCOMPATIBILITY in rare situations, may try to
    32 swap theory imports.
    33 
    34 
    35 *** Pure ***
    36 
    37 * Context-dependent token translations.  Default setup reverts locally
    38 fixed variables, and adds hilite markup for undeclared frees.
    39 
    40 * Unused theorems can be found using the new command 'unused_thms'.
    41 There are three ways of invoking it:
    42 
    43 (1) unused_thms
    44      Only finds unused theorems in the current theory.
    45 
    46 (2) unused_thms thy_1 ... thy_n -
    47      Finds unused theorems in the current theory and all of its ancestors,
    48      excluding the theories thy_1 ... thy_n and all of their ancestors.
    49 
    50 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
    51      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
    52      their ancestors, excluding the theories thy_1 ... thy_n and all of
    53      their ancestors.
    54 
    55 In order to increase the readability of the list produced by
    56 unused_thms, theorems that have been created by a particular instance
    57 of a theory command such as 'inductive' or 'function' are considered
    58 to belong to the same "group", meaning that if at least one theorem in
    59 this group is used, the other theorems in the same group are no longer
    60 reported as unused.  Moreover, if all theorems in the group are
    61 unused, only one theorem in the group is displayed.
    62 
    63 Note that proof objects have to be switched on in order for
    64 unused_thms to work properly (i.e. !proofs must be >= 1, which is
    65 usually the case when using Proof General with the default settings).
    66 
    67 * Authentic naming of facts disallows ad-hoc overwriting of previous
    68 theorems within the same name space.  INCOMPATIBILITY, need to remove
    69 duplicate fact bindings, or even accidental fact duplications.  Note
    70 that tools may maintain dynamically scoped facts systematically, using
    71 PureThy.add_thms_dynamic.
    72 
    73 * Command 'hide' now allows to hide from "fact" name space as well.
    74 
    75 * Eliminated destructive theorem database, simpset, claset, and
    76 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
    77 update of theories within ML code.
    78 
    79 * Eliminated theory ProtoPure.  Potential INCOMPATIBILITY.
    80 
    81 * Commands 'use' and 'ML' are now purely functional, operating on
    82 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
    83 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
    84 INCOMPATIBILITY.
    85 
    86 * Command 'setup': discontinued implicit version with ML reference.
    87 
    88 * Instantiation target allows for simultaneous specification of class
    89 instance operations together with an instantiation proof.
    90 Type-checking phase allows to refer to class operations uniformly.
    91 See HOL/Complex/Complex.thy for an Isar example and
    92 HOL/Library/Eval.thy for an ML example.
    93 
    94 * Indexing of literal facts: be more serious about including only
    95 facts from the visible specification/proof context, but not the
    96 background context (locale etc.).  Affects `prop` notation and method
    97 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
    98 situations.
    99 
   100 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   101 "(open)" option, which used to expose internal bound variables to the
   102 proof text.
   103 
   104 * Isar statements: removed obsolete case "rule_context".
   105 INCOMPATIBILITY, better use explicit fixes/assumes.
   106 
   107 * Locale proofs: default proof step now includes 'unfold_locales';
   108 hence 'proof' without argument may be used to unfold locale
   109 predicates.
   110 
   111 
   112 *** Document preparation ***
   113 
   114 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   115 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   116 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   117 spot); renamed link color from "darkblue" to "linkcolor" (default
   118 value unchanged, can be redefined via \definecolor); no longer sets
   119 "a4paper" option (unnecessary or even intrusive).
   120 
   121 * Antiquotation "lemma" takes a proposition and a simple method text
   122 as argument and asserts that the proposition is provable by the
   123 corresponding method invocation.  Prints text of proposition, as does
   124 antiquotation "prop".  A simple method text is either a method name or
   125 a method name plus (optional) method arguments in parentheses,
   126 mimicking the conventions known from Isar proof text.  Useful for
   127 illustration of presented theorems by particular examples.
   128 
   129 
   130 *** HOL ***
   131 
   132 * Merged theories Wellfounded_Recursion, Accessible_Part and
   133 Wellfounded_Relations to "Wellfounded.thy".
   134 
   135 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   136 
   137 * Class finite no longer treats UNIV as class parameter.  Use class
   138 enum from theory Library/Enum instead to achieve a similar effect.
   139 INCOMPATIBILITY.
   140 
   141 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   142 and "Cons".  INCOMPATIBILITY.
   143 
   144 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   145 Potential INCOMPATIBILITY.
   146 
   147 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   148 injective_fst_snd removed, use split_eta and prod_eqI instead.
   149 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   150 
   151 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   152 the same name in theory Orderings:
   153 
   154   less_trans
   155   less_linear
   156   le_imp_less_or_eq
   157   le_less_trans
   158   less_le_trans
   159   less_not_sym
   160   less_asym
   161 
   162 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   163 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   164 and different variable names.
   165 
   166 * Library/Option_ord.thy: Canonical order on option type.
   167 
   168 * Library/RBT.thy: New theory of red-black trees, an efficient
   169 implementation of finite maps.
   170 
   171 * Library/Countable.thy: Type class for countable types.
   172 
   173 * Theory Int: The representation of numerals has changed.  The infix
   174 operator BIT and the bit datatype with constructors B0 and B1 have
   175 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   176 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   177 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   178 accordingly.
   179 
   180 * Theory Nat: definition of <= and < on natural numbers no longer
   181 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   182 le_def and less_def have disappeared.  Consider lemmas not_less
   183 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   184 
   185 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   186 (whose purpose mainly is for various fold_set functionals) have been
   187 abandoned in favor of the existing algebraic classes
   188 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   189 lower_semilattice (resp. upper_semilattice) and linorder.
   190 INCOMPATIBILITY.
   191 
   192 * Theory Transitive_Closure: induct and cases rules now declare proper
   193 case_names ("base" and "step").  INCOMPATIBILITY.
   194 
   195 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   196 lattices.  The form set-specific version is available as
   197 Inductive.lfp_ordinal_induct_set.
   198 
   199 * Renamed theorems "power.simps" to "power_int.simps".
   200 
   201 * Class semiring_div provides basic abstract properties of semirings
   202 with division and modulo operations.  Subsumes former class dvd_mod.
   203 
   204 * Merged theories IntDef, Numeral and IntArith into unified theory
   205 Int.  INCOMPATIBILITY.
   206 
   207 * Theory Library/Code_Index: type "index" now represents natural
   208 numbers rather than integers.  INCOMPATIBILITY.
   209 
   210 * New class "uminus" with operation "uminus" (split of from class
   211 "minus" which now only has operation "minus", binary).
   212 INCOMPATIBILITY.
   213 
   214 * New primrec package.  Specification syntax conforms in style to
   215 definition/function/....  No separate induction rule is provided.  The
   216 "primrec" command distinguishes old-style and new-style specifications
   217 by syntax.  The former primrec package is now named OldPrimrecPackage.
   218 When adjusting theories, beware: constants stemming from new-style
   219 primrec specifications have authentic syntax.
   220 
   221 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   222 
   223 * Library/ListVector: new theory of arithmetic vector operations.
   224 
   225 * Library/Order_Relation: new theory of various orderings as sets of
   226 pairs.  Defines preorders, partial orders, linear orders and
   227 well-orders on sets and on types.
   228 
   229 * Constants "card", "internal_split", "option_map" now with authentic
   230 syntax.  INCOMPATIBILITY.
   231 
   232 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   233 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   234 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   235 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   236 Sup_set_def, le_def, less_def, option_map_def now with object
   237 equality.  INCOMPATIBILITY.
   238 
   239 * Method "induction_scheme" derives user-specified induction rules
   240 from well-founded induction and completeness of patterns. This factors
   241 out some operations that are done internally by the function package
   242 and makes them available separately. See "HOL/ex/Induction_Scheme.thy"
   243 for examples,
   244 
   245 * Records. Removed K_record, and replaced it by pure lambda term
   246 %x. c. The simplifier setup is now more robust against eta expansion.
   247 INCOMPATIBILITY: in cases explicitly referring to K_record.
   248 
   249 * Metis prover is now an order of magnitude faster, and also works
   250 with multithreading.
   251 
   252 * Metis: the maximum number of clauses that can be produced from a
   253 theorem is now given by the attribute max_clauses. Theorems that
   254 exceed this number are ignored, with a warning printed.
   255 
   256 * Sledgehammer no longer produces structured proofs by default. To
   257 enable, declare [[sledgehammer_full = true]]. Attributes
   258 reconstruction_modulus, reconstruction_sorts renamed
   259 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   260 
   261 * More flexible generation of measure functions for termination proofs:
   262 Measure functions can be declared by proving a rule of the form
   263 "is_measure f" and giving it the [measure_function] attribute. The
   264 "is_measure" predicate is logically meaningless (always true), and
   265 just guides the heuristic.  To find suitable measure functions, the
   266 termination prover sets up the goal "is_measure ?f" of the appropriate
   267 type and generates all solutions by prolog-style backwards proof using
   268 the declared rules.
   269 
   270 This setup also deals with rules like 
   271 
   272   "is_measure f ==> is_measure (list_size f)"
   273 
   274 which accomodates nested datatypes that recurse through lists. Similar
   275 rules are predeclared for products and option types.
   276 
   277 
   278 *** ZF ***
   279 
   280 * Renamed some theories to allow to loading both ZF and HOL in the
   281 same session:
   282 
   283   Datatype  -> Datatype_ZF
   284   Inductive -> Inductive_ZF
   285   Int       -> Int_ZF
   286   IntDiv    -> IntDiv_ZF
   287   Nat       -> Nat_ZF
   288   List      -> List_ZF
   289   Main      -> Main_ZF
   290 
   291 INCOMPATIBILITY: ZF theories that import individual theories below
   292 Main might need to be adapted.  Regular theory Main is still
   293 available, as trivial extension of Main_ZF.
   294 
   295 
   296 *** ML ***
   297 
   298 * Functor NamedThmsFun: data is available to the user as dynamic fact
   299 (of the same name).  Removed obsolete print command.
   300 
   301 * Removed obsolete "use_legacy_bindings" function.  INCOMPATIBILITY.
   302 
   303 * ML within Isar: antiquotation @{const name} or @{const
   304 name(typargs)} produces statically-checked Const term.
   305 
   306 * The ``print mode'' is now a thread-local value derived from a global
   307 template (the former print_mode reference), thus access becomes
   308 non-critical.  The global print_mode reference is for session
   309 management only; user-code should use print_mode_value,
   310 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   311 
   312 * Functions system/system_out provide a robust way to invoke external
   313 shell commands, with propagation of interrupts (after Poly/ML 5.2).
   314 Do not use OS.Process.system etc. from the basis library!
   315 
   316 
   317 *** System ***
   318 
   319 * YXML notation provides a simple and efficient alternative to
   320 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   321 isatool yxml as described in the Isabelle system manual.
   322 
   323 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   324 way of changing the user's settings is via
   325 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   326 script.
   327 
   328 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   329 in accordance with Proof General 3.7, which prefers GNU emacs.
   330 
   331 * Multithreading.max_threads := 0 refers to the number of actual CPU
   332 cores of the underlying machine, which is a good starting point for
   333 optimal performance tuning.  The corresponding usedir option -M allows
   334 "max" as an alias for "0".  WARNING: does not work on certain versions
   335 of Mac OS (with Poly/ML 5.1).
   336 
   337 * isatool tty runs Isabelle process with plain tty interaction;
   338 optional line editor may be specified via ISABELLE_LINE_EDITOR
   339 setting, the default settings attempt to locate "ledit" and "rlwrap".
   340 
   341 * isatool browser now works with Cygwin as well, using general
   342 "javapath" function defined in Isabelle process environment.
   343 
   344 * isabelle-process: non-ML sessions are run with "nice", to prevent
   345 Isabelle from flooding interactive front-ends (notably ProofGeneral /
   346 XEmacs).
   347 
   348 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   349 provides general wrapper for managing an Isabelle process in a robust
   350 fashion, with ``cooked'' output from stdin/stderr.
   351 
   352 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   353 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   354 
   355 
   356 
   357 New in Isabelle2007 (November 2007)
   358 -----------------------------------
   359 
   360 *** General ***
   361 
   362 * More uniform information about legacy features, notably a
   363 warning/error of "Legacy feature: ...", depending on the state of the
   364 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   365 legacy features will disappear eventually.
   366 
   367 * Theory syntax: the header format ``theory A = B + C:'' has been
   368 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   369 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   370 
   371 * Theory syntax: the old non-Isar theory file format has been
   372 discontinued altogether.  Note that ML proof scripts may still be used
   373 with Isar theories; migration is usually quite simple with the ML
   374 function use_legacy_bindings.  INCOMPATIBILITY.
   375 
   376 * Theory syntax: some popular names (e.g. 'class', 'declaration',
   377 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
   378 quotes.
   379 
   380 * Theory loader: be more serious about observing the static theory
   381 header specifications (including optional directories), but not the
   382 accidental file locations of previously successful loads.  The strict
   383 update policy of former update_thy is now already performed by
   384 use_thy, so the former has been removed; use_thys updates several
   385 theories simultaneously, just as 'imports' within a theory header
   386 specification, but without merging the results.  Potential
   387 INCOMPATIBILITY: may need to refine theory headers and commands
   388 ROOT.ML which depend on load order.
   389 
   390 * Theory loader: optional support for content-based file
   391 identification, instead of the traditional scheme of full physical
   392 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
   393 (cf. the system manual).  The new scheme allows to work with
   394 non-finished theories in persistent session images, such that source
   395 files may be moved later on without requiring reloads.
   396 
   397 * Theory loader: old-style ML proof scripts being *attached* to a thy
   398 file (with the same base name as the theory) are considered a legacy
   399 feature, which will disappear eventually. Even now, the theory loader
   400 no longer maintains dependencies on such files.
   401 
   402 * Syntax: the scope for resolving ambiguities via type-inference is
   403 now limited to individual terms, instead of whole simultaneous
   404 specifications as before. This greatly reduces the complexity of the
   405 syntax module and improves flexibility by separating parsing and
   406 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
   407 'fixes' etc.) are required in rare situations.
   408 
   409 * Syntax: constants introduced by new-style packages ('definition',
   410 'abbreviation' etc.) are passed through the syntax module in
   411 ``authentic mode''. This means that associated mixfix annotations
   412 really stick to such constants, independently of potential name space
   413 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   414 trees are represented slightly differently, may need to adapt syntax
   415 translations accordingly. Use CONST marker in 'translations' and
   416 @{const_syntax} antiquotation in 'parse_translation' etc.
   417 
   418 * Legacy goal package: reduced interface to the bare minimum required
   419 to keep existing proof scripts running.  Most other user-level
   420 functions are now part of the OldGoals structure, which is *not* open
   421 by default (consider isatool expandshort before open OldGoals).
   422 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   423 these tend to cause confusion about the actual goal (!) context being
   424 used here, which is not necessarily the same as the_context().
   425 
   426 * Command 'find_theorems': supports "*" wild-card in "name:"
   427 criterion; "with_dups" option.  Certain ProofGeneral versions might
   428 support a specific search form (see ProofGeneral/CHANGES).
   429 
   430 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   431 by default, which means that "prems" (and also "fixed variables") are
   432 suppressed from proof state output.  Note that the ProofGeneral
   433 settings mechanism allows to change and save options persistently, but
   434 older versions of Isabelle will fail to start up if a negative prems
   435 limit is imposed.
   436 
   437 * Local theory targets may be specified by non-nested blocks of
   438 ``context/locale/class ... begin'' followed by ``end''.  The body may
   439 contain definitions, theorems etc., including any derived mechanism
   440 that has been implemented on top of these primitives.  This concept
   441 generalizes the existing ``theorem (in ...)'' towards more versatility
   442 and scalability.
   443 
   444 * Proof General interface: proper undo of final 'end' command;
   445 discontinued Isabelle/classic mode (ML proof scripts).
   446 
   447 
   448 *** Document preparation ***
   449 
   450 * Added antiquotation @{theory name} which prints the given name,
   451 after checking that it refers to a valid ancestor theory in the
   452 current context.
   453 
   454 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   455 check the given source text as ML type/structure, printing verbatim.
   456 
   457 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   458 "c args == rhs" given in the current context.  (Any number of
   459 arguments may be given on the LHS.)
   460 
   461 
   462 *** Pure ***
   463 
   464 * The 'class' package offers a combination of axclass and locale to
   465 achieve Haskell-like type classes in Isabelle.  Definitions and
   466 theorems within a class context produce both relative results (with
   467 implicit parameters according to the locale context), and polymorphic
   468 constants with qualified polymorphism (according to the class
   469 context).  Within the body context of a 'class' target, a separate
   470 syntax layer ("user space type system") takes care of converting
   471 between global polymorphic consts and internal locale representation.
   472 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   473 "isatool doc classes" provides a tutorial.
   474 
   475 * Generic code generator framework allows to generate executable
   476 code for ML and Haskell (including Isabelle classes).  A short usage
   477 sketch:
   478 
   479     internal compilation:
   480         export_code <list of constants (term syntax)> in SML
   481     writing SML code to a file:
   482         export_code <list of constants (term syntax)> in SML <filename>
   483     writing OCaml code to a file:
   484         export_code <list of constants (term syntax)> in OCaml <filename>
   485     writing Haskell code to a bunch of files:
   486         export_code <list of constants (term syntax)> in Haskell <filename>
   487 
   488     evaluating closed propositions to True/False using code generation:
   489         method ``eval''
   490 
   491 Reasonable default setup of framework in HOL.
   492 
   493 Theorem attributs for selecting and transforming function equations theorems:
   494 
   495     [code fun]:        select a theorem as function equation for a specific constant
   496     [code fun del]:    deselect a theorem as function equation for a specific constant
   497     [code inline]:     select an equation theorem for unfolding (inlining) in place
   498     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   499 
   500 User-defined serializations (target in {SML, OCaml, Haskell}):
   501 
   502     code_const <and-list of constants (term syntax)>
   503       {(target) <and-list of const target syntax>}+
   504 
   505     code_type <and-list of type constructors>
   506       {(target) <and-list of type target syntax>}+
   507 
   508     code_instance <and-list of instances>
   509       {(target)}+
   510         where instance ::= <type constructor> :: <class>
   511 
   512     code_class <and_list of classes>
   513       {(target) <and-list of class target syntax>}+
   514         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   515 
   516 code_instance and code_class only are effective to target Haskell.
   517 
   518 For example usage see src/HOL/ex/Codegenerator.thy and
   519 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   520 generation from Isabelle/HOL theories is available via "isatool doc
   521 codegen".
   522 
   523 * Code generator: consts in 'consts_code' Isar commands are now
   524 referred to by usual term syntax (including optional type
   525 annotations).
   526 
   527 * Command 'no_translations' removes translation rules from theory
   528 syntax.
   529 
   530 * Overloaded definitions are now actually checked for acyclic
   531 dependencies.  The overloading scheme is slightly more general than
   532 that of Haskell98, although Isabelle does not demand an exact
   533 correspondence to type class and instance declarations.
   534 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   535 exotic versions of overloading -- at the discretion of the user!
   536 
   537 Polymorphic constants are represented via type arguments, i.e. the
   538 instantiation that matches an instance against the most general
   539 declaration given in the signature.  For example, with the declaration
   540 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   541 as c(nat).  Overloading is essentially simultaneous structural
   542 recursion over such type arguments.  Incomplete specification patterns
   543 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   544 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   545 Command 'print_theory' outputs the normalized system of recursive
   546 equations, see section "definitions".
   547 
   548 * Configuration options are maintained within the theory or proof
   549 context (with name and type bool/int/string), providing a very simple
   550 interface to a poor-man's version of general context data.  Tools may
   551 declare options in ML (e.g. using Attrib.config_int) and then refer to
   552 these values using Config.get etc.  Users may change options via an
   553 associated attribute of the same name.  This form of context
   554 declaration works particularly well with commands 'declare' or
   555 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   556 very easy to avoid global references, which would not observe Isar
   557 toplevel undo/redo and fail to work with multithreading.
   558 
   559 Various global ML references of Pure and HOL have been turned into
   560 configuration options:
   561 
   562   Unify.search_bound		unify_search_bound
   563   Unify.trace_bound		unify_trace_bound
   564   Unify.trace_simp		unify_trace_simp
   565   Unify.trace_types		unify_trace_types
   566   Simplifier.simp_depth_limit	simp_depth_limit
   567   Blast.depth_limit		blast_depth_limit
   568   DatatypeProp.dtK		datatype_distinctness_limit
   569   fast_arith_neq_limit  	fast_arith_neq_limit
   570   fast_arith_split_limit	fast_arith_split_limit
   571 
   572 * Named collections of theorems may be easily installed as context
   573 data using the functor NamedThmsFun (see also
   574 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   575 attributes; there is also a toplevel print command.  This facility is
   576 just a common case of general context data, which is the preferred way
   577 for anything more complex than just a list of facts in canonical
   578 order.
   579 
   580 * Isar: command 'declaration' augments a local theory by generic
   581 declaration functions written in ML.  This enables arbitrary content
   582 being added to the context, depending on a morphism that tells the
   583 difference of the original declaration context wrt. the application
   584 context encountered later on.
   585 
   586 * Isar: proper interfaces for simplification procedures.  Command
   587 'simproc_setup' declares named simprocs (with match patterns, and body
   588 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   589 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   590 
   591 * Isar: an extra pair of brackets around attribute declarations
   592 abbreviates a theorem reference involving an internal dummy fact,
   593 which will be ignored later --- only the effect of the attribute on
   594 the background context will persist.  This form of in-place
   595 declarations is particularly useful with commands like 'declare' and
   596 'using', for example ``have A using [[simproc a]] by simp''.
   597 
   598 * Isar: method "assumption" (and implicit closing of subproofs) now
   599 takes simple non-atomic goal assumptions into account: after applying
   600 an assumption as a rule the resulting subgoals are solved by atomic
   601 assumption steps.  This is particularly useful to finish 'obtain'
   602 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   603 without referring to the original premise "!!x. P x ==> thesis" in the
   604 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   605 more permissive.
   606 
   607 * Isar: implicit use of prems from the Isar proof context is
   608 considered a legacy feature.  Common applications like ``have A .''
   609 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   610 referencing facts explicitly here improves readability and
   611 maintainability of proof texts.
   612 
   613 * Isar: improper proof element 'guess' is like 'obtain', but derives
   614 the obtained context from the course of reasoning!  For example:
   615 
   616   assume "EX x y. A x & B y"   -- "any previous fact"
   617   then guess x and y by clarify
   618 
   619 This technique is potentially adventurous, depending on the facts and
   620 proof tools being involved here.
   621 
   622 * Isar: known facts from the proof context may be specified as literal
   623 propositions, using ASCII back-quote syntax.  This works wherever
   624 named facts used to be allowed so far, in proof commands, proof
   625 methods, attributes etc.  Literal facts are retrieved from the context
   626 according to unification of type and term parameters.  For example,
   627 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   628 theorems in the current context, then these are valid literal facts:
   629 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   630 
   631 There is also a proof method "fact" which does the same composition
   632 for explicit goal states, e.g. the following proof texts coincide with
   633 certain special cases of literal facts:
   634 
   635   have "A" by fact                 ==  note `A`
   636   have "A ==> B" by fact           ==  note `A ==> B`
   637   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   638   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   639 
   640 * Isar: ":" (colon) is no longer a symbolic identifier character in
   641 outer syntax.  Thus symbolic identifiers may be used without
   642 additional white space in declarations like this: ``assume *: A''.
   643 
   644 * Isar: 'print_facts' prints all local facts of the current context,
   645 both named and unnamed ones.
   646 
   647 * Isar: 'def' now admits simultaneous definitions, e.g.:
   648 
   649   def x == "t" and y == "u"
   650 
   651 * Isar: added command 'unfolding', which is structurally similar to
   652 'using', but affects both the goal state and facts by unfolding given
   653 rewrite rules.  Thus many occurrences of the 'unfold' method or
   654 'unfolded' attribute may be replaced by first-class proof text.
   655 
   656 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   657 and command 'unfolding' now all support object-level equalities
   658 (potentially conditional).  The underlying notion of rewrite rule is
   659 analogous to the 'rule_format' attribute, but *not* that of the
   660 Simplifier (which is usually more generous).
   661 
   662 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   663 premises of a theorem by n. Useful in conjunction with drule.
   664 
   665 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   666 method expression within a sandbox consisting of the first N
   667 sub-goals, which need to exist.  For example, ``simp_all [3]''
   668 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   669 simplifies all new goals that emerge from applying rule foo to the
   670 originally first one.
   671 
   672 * Isar: schematic goals are no longer restricted to higher-order
   673 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   674 expected.
   675 
   676 * Isar: the conclusion of a long theorem statement is now either
   677 'shows' (a simultaneous conjunction, as before), or 'obtains'
   678 (essentially a disjunction of cases with local parameters and
   679 assumptions).  The latter allows to express general elimination rules
   680 adequately; in this notation common elimination rules look like this:
   681 
   682   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   683     assumes "EX x. P x"
   684     obtains x where "P x"
   685 
   686   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   687     assumes "A & B"
   688     obtains A and B
   689 
   690   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   691     assumes "A | B"
   692     obtains
   693       A
   694     | B
   695 
   696 The subsequent classical rules even refer to the formal "thesis"
   697 explicitly:
   698 
   699   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   700     obtains "~ thesis"
   701 
   702   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   703     obtains "thesis ==> something"
   704 
   705 The actual proof of an 'obtains' statement is analogous to that of the
   706 Isar proof element 'obtain', only that there may be several cases.
   707 Optional case names may be specified in parentheses; these will be
   708 available both in the present proof and as annotations in the
   709 resulting rule, for later use with the 'cases' method (cf. attribute
   710 case_names).
   711 
   712 * Isar: the assumptions of a long theorem statement are available as
   713 "assms" fact in the proof context.  This is more appropriate than the
   714 (historical) "prems", which refers to all assumptions of the current
   715 context, including those from the target locale, proof body etc.
   716 
   717 * Isar: 'print_statement' prints theorems from the current theory or
   718 proof context in long statement form, according to the syntax of a
   719 top-level lemma.
   720 
   721 * Isar: 'obtain' takes an optional case name for the local context
   722 introduction rule (default "that").
   723 
   724 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   725 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   726 to occur.
   727 
   728 * Pure: syntax "CONST name" produces a fully internalized constant
   729 according to the current context.  This is particularly useful for
   730 syntax translations that should refer to internal constant
   731 representations independently of name spaces.
   732 
   733 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   734 instead of "FOO ". This allows multiple binder declarations to coexist
   735 in the same context.  INCOMPATIBILITY.
   736 
   737 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   738 primitive that also works in a locale context (both for constants and
   739 fixed variables). Type declaration and internal syntactic representation
   740 of given constants retrieved from the context. Likewise, the
   741 'no_notation' command allows to remove given syntax annotations from the
   742 current context.
   743 
   744 * Isar/locales: new derived specification elements 'axiomatization',
   745 'definition', 'abbreviation', which support type-inference, admit
   746 object-level specifications (equality, equivalence).  See also the
   747 isar-ref manual.  Examples:
   748 
   749   axiomatization
   750     eq  (infix "===" 50) where
   751     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   752 
   753   definition "f x y = x + y + 1"
   754   definition g where "g x = f x x"
   755 
   756   abbreviation
   757     neq  (infix "=!=" 50) where
   758     "x =!= y == ~ (x === y)"
   759 
   760 These specifications may be also used in a locale context.  Then the
   761 constants being introduced depend on certain fixed parameters, and the
   762 constant name is qualified by the locale base name.  An internal
   763 abbreviation takes care for convenient input and output, making the
   764 parameters implicit and using the original short name.  See also
   765 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   766 entities from a monomorphic theory.
   767 
   768 Presently, abbreviations are only available 'in' a target locale, but
   769 not inherited by general import expressions.  Also note that
   770 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   771 'translations' in common applications.  The "no_abbrevs" print mode
   772 prevents folding of abbreviations in term output.
   773 
   774 Concrete syntax is attached to specified constants in internal form,
   775 independently of name spaces.  The parse tree representation is
   776 slightly different -- use 'notation' instead of raw 'syntax', and
   777 'translations' with explicit "CONST" markup to accommodate this.
   778 
   779 * Pure/Isar: unified syntax for new-style specification mechanisms
   780 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   781 full type inference and dummy patterns ("_").  For example:
   782 
   783   definition "K x _ = x"
   784 
   785   inductive conj for A B
   786   where "A ==> B ==> conj A B"
   787 
   788 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   789 the current context.  Print mode "no_abbrevs" prevents inversion of
   790 abbreviations on output.
   791 
   792 * Isar/locales: improved parameter handling: use of locales "var" and
   793 "struct" no longer necessary; - parameter renamings are no longer
   794 required to be injective.  For example, this allows to define
   795 endomorphisms as locale endom = homom mult mult h.
   796 
   797 * Isar/locales: changed the way locales with predicates are defined.
   798 Instead of accumulating the specification, the imported expression is
   799 now an interpretation.  INCOMPATIBILITY: different normal form of
   800 locale expressions.  In particular, in interpretations of locales with
   801 predicates, goals repesenting already interpreted fragments are not
   802 removed automatically.  Use methods `intro_locales' and
   803 `unfold_locales'; see below.
   804 
   805 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   806 provide backward reasoning on locales predicates.  The methods are
   807 aware of interpretations and discharge corresponding goals.
   808 `intro_locales' is less aggressive then `unfold_locales' and does not
   809 unfold predicates to assumptions.
   810 
   811 * Isar/locales: the order in which locale fragments are accumulated
   812 has changed.  This enables to override declarations from fragments due
   813 to interpretations -- for example, unwanted simp rules.
   814 
   815 * Isar/locales: interpretation in theories and proof contexts has been
   816 extended.  One may now specify (and prove) equations, which are
   817 unfolded in interpreted theorems.  This is useful for replacing
   818 defined concepts (constants depending on locale parameters) by
   819 concepts already existing in the target context.  Example:
   820 
   821   interpretation partial_order ["op <= :: [int, int] => bool"]
   822     where "partial_order.less (op <=) (x::int) y = (x < y)"
   823 
   824 Typically, the constant `partial_order.less' is created by a
   825 definition specification element in the context of locale
   826 partial_order.
   827 
   828 * Method "induct": improved internal context management to support
   829 local fixes and defines on-the-fly. Thus explicit meta-level
   830 connectives !!  and ==> are rarely required anymore in inductive goals
   831 (using object-logic connectives for this purpose has been long
   832 obsolete anyway). Common proof patterns are explained in
   833 src/HOL/Induct/Common_Patterns.thy, see also
   834 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   835 examples.
   836 
   837 * Method "induct": improved handling of simultaneous goals. Instead of
   838 introducing object-level conjunction, the statement is now split into
   839 several conclusions, while the corresponding symbolic cases are nested
   840 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   841 see src/HOL/Induct/Common_Patterns.thy, for example.
   842 
   843 * Method "induct": mutual induction rules are now specified as a list
   844 of rule sharing the same induction cases. HOL packages usually provide
   845 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   846 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   847 mutual induction rules differently, i.e. like this:
   848 
   849   (induct rule: foo_bar.inducts)
   850   (induct set: foo bar)
   851   (induct pred: foo bar)
   852   (induct type: foo bar)
   853 
   854 The ML function ProjectRule.projections turns old-style rules into the
   855 new format.
   856 
   857 * Method "coinduct": dual of induction, see
   858 src/HOL/Library/Coinductive_List.thy for various examples.
   859 
   860 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   861 considered a legacy feature.
   862 
   863 * Attribute "symmetric" produces result with standardized schematic
   864 variables (index 0).  Potential INCOMPATIBILITY.
   865 
   866 * Simplifier: by default the simplifier trace only shows top level
   867 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   868 default. Thus there is less danger of being flooded by the trace. The
   869 trace indicates where parts have been suppressed.
   870   
   871 * Provers/classical: removed obsolete classical version of elim_format
   872 attribute; classical elim/dest rules are now treated uniformly when
   873 manipulating the claset.
   874 
   875 * Provers/classical: stricter checks to ensure that supplied intro,
   876 dest and elim rules are well-formed; dest and elim rules must have at
   877 least one premise.
   878 
   879 * Provers/classical: attributes dest/elim/intro take an optional
   880 weight argument for the rule (just as the Pure versions).  Weights are
   881 ignored by automated tools, but determine the search order of single
   882 rule steps.
   883 
   884 * Syntax: input syntax now supports dummy variable binding "%_. b",
   885 where the body does not mention the bound variable.  Note that dummy
   886 patterns implicitly depend on their context of bounds, which makes
   887 "{_. _}" match any set comprehension as expected.  Potential
   888 INCOMPATIBILITY -- parse translations need to cope with syntactic
   889 constant "_idtdummy" in the binding position.
   890 
   891 * Syntax: removed obsolete syntactic constant "_K" and its associated
   892 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   893 for example "A -> B" => "Pi A (%_. B)".
   894 
   895 * Pure: 'class_deps' command visualizes the subclass relation, using
   896 the graph browser tool.
   897 
   898 * Pure: 'print_theory' now suppresses certain internal declarations by
   899 default; use '!' option for full details.
   900 
   901 
   902 *** HOL ***
   903 
   904 * Method "metis" proves goals by applying the Metis general-purpose
   905 resolution prover (see also http://gilith.com/software/metis/).
   906 Examples are in the directory MetisExamples.  WARNING: the
   907 Isabelle/HOL-Metis integration does not yet work properly with
   908 multi-threading.
   909   
   910 * Command 'sledgehammer' invokes external automatic theorem provers as
   911 background processes.  It generates calls to the "metis" method if
   912 successful. These can be pasted into the proof.  Users do not have to
   913 wait for the automatic provers to return.  WARNING: does not really
   914 work with multi-threading.
   915 
   916 * New "auto_quickcheck" feature tests outermost goal statements for
   917 potential counter-examples.  Controlled by ML references
   918 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   919 5000 milliseconds).  Fails silently if statements is outside of
   920 executable fragment, or any other codgenerator problem occurs.
   921 
   922 * New constant "undefined" with axiom "undefined x = undefined".
   923 
   924 * Added class "HOL.eq", allowing for code generation with polymorphic
   925 equality.
   926 
   927 * Some renaming of class constants due to canonical name prefixing in
   928 the new 'class' package:
   929 
   930     HOL.abs ~> HOL.abs_class.abs
   931     HOL.divide ~> HOL.divide_class.divide
   932     0 ~> HOL.zero_class.zero
   933     1 ~> HOL.one_class.one
   934     op + ~> HOL.plus_class.plus
   935     op - ~> HOL.minus_class.minus
   936     uminus ~> HOL.minus_class.uminus
   937     op * ~> HOL.times_class.times
   938     op < ~> HOL.ord_class.less
   939     op <= > HOL.ord_class.less_eq
   940     Nat.power ~> Power.power_class.power
   941     Nat.size ~> Nat.size_class.size
   942     Numeral.number_of ~> Numeral.number_class.number_of
   943     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
   944     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
   945     Orderings.min ~> Orderings.ord_class.min
   946     Orderings.max ~> Orderings.ord_class.max
   947     Divides.op div ~> Divides.div_class.div
   948     Divides.op mod ~> Divides.div_class.mod
   949     Divides.op dvd ~> Divides.div_class.dvd
   950 
   951 INCOMPATIBILITY.  Adaptions may be required in the following cases:
   952 
   953 a) User-defined constants using any of the names "plus", "minus",
   954 "times", "less" or "less_eq". The standard syntax translations for
   955 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
   956 names.
   957 
   958 b) Variables named "plus", "minus", "times", "less", "less_eq"
   959 INCOMPATIBILITY: use more specific names.
   960 
   961 c) Permutative equations (e.g. "a + b = b + a")
   962 Since the change of names also changes the order of terms, permutative
   963 rewrite rules may get applied in a different order. Experience shows
   964 that this is rarely the case (only two adaptions in the whole Isabelle
   965 distribution).  INCOMPATIBILITY: rewrite proofs
   966 
   967 d) ML code directly refering to constant names
   968 This in general only affects hand-written proof tactics, simprocs and
   969 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
   970 Consider using @{const_name} antiquotation.
   971 
   972 * New class "default" with associated constant "default".
   973 
   974 * Function "sgn" is now overloaded and available on int, real, complex
   975 (and other numeric types), using class "sgn".  Two possible defs of
   976 sgn are given as equational assumptions in the classes sgn_if and
   977 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   978 INCOMPATIBILITY.
   979 
   980 * Locale "partial_order" now unified with class "order" (cf. theory
   981 Orderings), added parameter "less".  INCOMPATIBILITY.
   982 
   983 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
   984 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   985 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   986 
   987 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   988 changed order of proof goals in instance proofs.
   989 
   990 * The transitivity reasoner for partial and linear orders is set up
   991 for classes "order" and "linorder".  Instances of the reasoner are available
   992 in all contexts importing or interpreting the corresponding locales.
   993 Method "order" invokes the reasoner separately; the reasoner
   994 is also integrated with the Simplifier as a solver.  Diagnostic
   995 command 'print_orders' shows the available instances of the reasoner
   996 in the current context.
   997 
   998 * Localized monotonicity predicate in theory "Orderings"; integrated
   999 lemmas max_of_mono and min_of_mono with this predicate.
  1000 INCOMPATIBILITY.
  1001 
  1002 * Formulation of theorem "dense" changed slightly due to integration
  1003 with new class dense_linear_order.
  1004 
  1005 * Uniform lattice theory development in HOL.
  1006 
  1007     constants "meet" and "join" now named "inf" and "sup"
  1008     constant "Meet" now named "Inf"
  1009 
  1010     classes "meet_semilorder" and "join_semilorder" now named
  1011       "lower_semilattice" and "upper_semilattice"
  1012     class "lorder" now named "lattice"
  1013     class "comp_lat" now named "complete_lattice"
  1014 
  1015     Instantiation of lattice classes allows explicit definitions
  1016     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1017 
  1018   INCOMPATIBILITY.  Theorem renames:
  1019 
  1020     meet_left_le            ~> inf_le1
  1021     meet_right_le           ~> inf_le2
  1022     join_left_le            ~> sup_ge1
  1023     join_right_le           ~> sup_ge2
  1024     meet_join_le            ~> inf_sup_ord
  1025     le_meetI                ~> le_infI
  1026     join_leI                ~> le_supI
  1027     le_meet                 ~> le_inf_iff
  1028     le_join                 ~> ge_sup_conv
  1029     meet_idempotent         ~> inf_idem
  1030     join_idempotent         ~> sup_idem
  1031     meet_comm               ~> inf_commute
  1032     join_comm               ~> sup_commute
  1033     meet_leI1               ~> le_infI1
  1034     meet_leI2               ~> le_infI2
  1035     le_joinI1               ~> le_supI1
  1036     le_joinI2               ~> le_supI2
  1037     meet_assoc              ~> inf_assoc
  1038     join_assoc              ~> sup_assoc
  1039     meet_left_comm          ~> inf_left_commute
  1040     meet_left_idempotent    ~> inf_left_idem
  1041     join_left_comm          ~> sup_left_commute
  1042     join_left_idempotent    ~> sup_left_idem
  1043     meet_aci                ~> inf_aci
  1044     join_aci                ~> sup_aci
  1045     le_def_meet             ~> le_iff_inf
  1046     le_def_join             ~> le_iff_sup
  1047     join_absorp2            ~> sup_absorb2
  1048     join_absorp1            ~> sup_absorb1
  1049     meet_absorp1            ~> inf_absorb1
  1050     meet_absorp2            ~> inf_absorb2
  1051     meet_join_absorp        ~> inf_sup_absorb
  1052     join_meet_absorp        ~> sup_inf_absorb
  1053     distrib_join_le         ~> distrib_sup_le
  1054     distrib_meet_le         ~> distrib_inf_le
  1055 
  1056     add_meet_distrib_left   ~> add_inf_distrib_left
  1057     add_join_distrib_left   ~> add_sup_distrib_left
  1058     is_join_neg_meet        ~> is_join_neg_inf
  1059     is_meet_neg_join        ~> is_meet_neg_sup
  1060     add_meet_distrib_right  ~> add_inf_distrib_right
  1061     add_join_distrib_right  ~> add_sup_distrib_right
  1062     add_meet_join_distribs  ~> add_sup_inf_distribs
  1063     join_eq_neg_meet        ~> sup_eq_neg_inf
  1064     meet_eq_neg_join        ~> inf_eq_neg_sup
  1065     add_eq_meet_join        ~> add_eq_inf_sup
  1066     meet_0_imp_0            ~> inf_0_imp_0
  1067     join_0_imp_0            ~> sup_0_imp_0
  1068     meet_0_eq_0             ~> inf_0_eq_0
  1069     join_0_eq_0             ~> sup_0_eq_0
  1070     neg_meet_eq_join        ~> neg_inf_eq_sup
  1071     neg_join_eq_meet        ~> neg_sup_eq_inf
  1072     join_eq_if              ~> sup_eq_if
  1073 
  1074     mono_meet               ~> mono_inf
  1075     mono_join               ~> mono_sup
  1076     meet_bool_eq            ~> inf_bool_eq
  1077     join_bool_eq            ~> sup_bool_eq
  1078     meet_fun_eq             ~> inf_fun_eq
  1079     join_fun_eq             ~> sup_fun_eq
  1080     meet_set_eq             ~> inf_set_eq
  1081     join_set_eq             ~> sup_set_eq
  1082     meet1_iff               ~> inf1_iff
  1083     meet2_iff               ~> inf2_iff
  1084     meet1I                  ~> inf1I
  1085     meet2I                  ~> inf2I
  1086     meet1D1                 ~> inf1D1
  1087     meet2D1                 ~> inf2D1
  1088     meet1D2                 ~> inf1D2
  1089     meet2D2                 ~> inf2D2
  1090     meet1E                  ~> inf1E
  1091     meet2E                  ~> inf2E
  1092     join1_iff               ~> sup1_iff
  1093     join2_iff               ~> sup2_iff
  1094     join1I1                 ~> sup1I1
  1095     join2I1                 ~> sup2I1
  1096     join1I1                 ~> sup1I1
  1097     join2I2                 ~> sup1I2
  1098     join1CI                 ~> sup1CI
  1099     join2CI                 ~> sup2CI
  1100     join1E                  ~> sup1E
  1101     join2E                  ~> sup2E
  1102 
  1103     is_meet_Meet            ~> is_meet_Inf
  1104     Meet_bool_def           ~> Inf_bool_def
  1105     Meet_fun_def            ~> Inf_fun_def
  1106     Meet_greatest           ~> Inf_greatest
  1107     Meet_lower              ~> Inf_lower
  1108     Meet_set_def            ~> Inf_set_def
  1109 
  1110     Sup_def                 ~> Sup_Inf
  1111     Sup_bool_eq             ~> Sup_bool_def
  1112     Sup_fun_eq              ~> Sup_fun_def
  1113     Sup_set_eq              ~> Sup_set_def
  1114 
  1115     listsp_meetI            ~> listsp_infI
  1116     listsp_meet_eq          ~> listsp_inf_eq
  1117 
  1118     meet_min                ~> inf_min
  1119     join_max                ~> sup_max
  1120 
  1121 * Added syntactic class "size"; overloaded constant "size" now has
  1122 type "'a::size ==> bool"
  1123 
  1124 * Internal reorganisation of `size' of datatypes: size theorems
  1125 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1126 simplification rules by default!); theorems "prod.size" now named
  1127 "*.size".
  1128 
  1129 * Class "div" now inherits from class "times" rather than "type".
  1130 INCOMPATIBILITY.
  1131 
  1132 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1133 Linorder etc.  have disappeared; operations defined in terms of
  1134 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1135 
  1136 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1137 
  1138 * HOL-Word: New extensive library and type for generic, fixed size
  1139 machine words, with arithemtic, bit-wise, shifting and rotating
  1140 operations, reflection into int, nat, and bool lists, automation for
  1141 linear arithmetic (by automatic reflection into nat or int), including
  1142 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1143 arithmetic type classes, supporting automatic simplification of
  1144 numerals on all operations.
  1145 
  1146 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1147 
  1148 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1149 
  1150 * Code generator library theories:
  1151   - Code_Integer represents HOL integers by big integer literals in target
  1152     languages.
  1153   - Code_Char represents HOL characters by character literals in target
  1154     languages.
  1155   - Code_Char_chr like Code_Char, but also offers treatment of character
  1156     codes; includes Code_Integer.
  1157   - Executable_Set allows to generate code for finite sets using lists.
  1158   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1159     denominator).
  1160   - Executable_Real implements a subset of real numbers, namly those
  1161     representable by rational numbers.
  1162   - Efficient_Nat implements natural numbers by integers, which in general will
  1163     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1164     includes Code_Integer.
  1165   - Code_Index provides an additional datatype index which is mapped to
  1166     target-language built-in integers.
  1167   - Code_Message provides an additional datatype message_string which is isomorphic to
  1168     strings; messages are mapped to target-language strings.
  1169 
  1170 * New package for inductive predicates
  1171 
  1172   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1173 
  1174     inductive
  1175       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1176       for z_1 :: U_1 and ... and z_n :: U_m
  1177     where
  1178       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1179     | ...
  1180 
  1181   with full support for type-inference, rather than
  1182 
  1183     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1184 
  1185     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1186     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1187 
  1188     inductive "s z_1 ... z_m"
  1189     intros
  1190       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1191       ...
  1192 
  1193   For backward compatibility, there is a wrapper allowing inductive
  1194   sets to be defined with the new package via
  1195 
  1196     inductive_set
  1197       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1198       for z_1 :: U_1 and ... and z_n :: U_m
  1199     where
  1200       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1201     | ...
  1202 
  1203   or
  1204 
  1205     inductive_set
  1206       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1207       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1208       for z_1 :: U_1 and ... and z_n :: U_m
  1209     where
  1210       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1211     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1212     | ...
  1213 
  1214   if the additional syntax "p ..." is required.
  1215 
  1216   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1217   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1218 
  1219   INCOMPATIBILITIES:
  1220 
  1221   - Since declaration and definition of inductive sets or predicates
  1222     is no longer separated, abbreviations involving the newly
  1223     introduced sets or predicates must be specified together with the
  1224     introduction rules after the 'where' keyword (see above), rather
  1225     than before the actual inductive definition.
  1226 
  1227   - The variables in induction and elimination rules are now
  1228     quantified in the order of their occurrence in the introduction
  1229     rules, rather than in alphabetical order. Since this may break
  1230     some proofs, these proofs either have to be repaired, e.g. by
  1231     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1232     statements of the form
  1233 
  1234       case (rule_i a_i_1 ... a_i_{k_i})
  1235 
  1236     or the old order of quantification has to be restored by explicitly adding
  1237     meta-level quantifiers in the introduction rules, i.e.
  1238 
  1239       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1240 
  1241   - The format of the elimination rules is now
  1242 
  1243       p z_1 ... z_m x_1 ... x_n ==>
  1244         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1245         ==> ... ==> P
  1246 
  1247     for predicates and
  1248 
  1249       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1250         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1251         ==> ... ==> P
  1252 
  1253     for sets rather than
  1254 
  1255       x : s z_1 ... z_m ==>
  1256         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1257         ==> ... ==> P
  1258 
  1259     This may require terms in goals to be expanded to n-tuples
  1260     (e.g. using case_tac or simplification with the split_paired_all
  1261     rule) before the above elimination rule is applicable.
  1262 
  1263   - The elimination or case analysis rules for (mutually) inductive
  1264     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1265     list of rules "p_1_..._p_k.elims" is no longer available.
  1266 
  1267 * New package "function"/"fun" for general recursive functions,
  1268 supporting mutual and nested recursion, definitions in local contexts,
  1269 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1270 for small examples, and the separate tutorial on the function
  1271 package. The old recdef "package" is still available as before, but
  1272 users are encouraged to use the new package.
  1273 
  1274 * Method "lexicographic_order" automatically synthesizes termination
  1275 relations as lexicographic combinations of size measures. 
  1276 
  1277 * Case-expressions allow arbitrary constructor-patterns (including
  1278 "_") and take their order into account, like in functional
  1279 programming.  Internally, this is translated into nested
  1280 case-expressions; missing cases are added and mapped to the predefined
  1281 constant "undefined". In complicated cases printing may no longer show
  1282 the original input but the internal form. Lambda-abstractions allow
  1283 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1284 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1285 variable.
  1286 
  1287 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1288 is an abbreviation for "of_nat :: nat => int". The simplification
  1289 rules for "of_nat" have been changed to work like "int" did
  1290 previously.  Potential INCOMPATIBILITY:
  1291   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1292   - of_nat_diff and of_nat_mult are no longer default simp rules
  1293 
  1294 * Method "algebra" solves polynomial equations over (semi)rings using
  1295 Groebner bases. The (semi)ring structure is defined by locales and the
  1296 tool setup depends on that generic context. Installing the method for
  1297 a specific type involves instantiating the locale and possibly adding
  1298 declarations for computation on the coefficients.  The method is
  1299 already instantiated for natural numbers and for the axiomatic class
  1300 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1301 CALCULEMUS 2007 for the general principles underlying this
  1302 architecture of context-aware proof-tools.
  1303 
  1304 * Method "ferrack" implements quantifier elimination over
  1305 special-purpose dense linear orders using locales (analogous to
  1306 "algebra"). The method is already installed for class
  1307 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1308 rat, etc.
  1309 
  1310 * Former constant "List.op @" now named "List.append".  Use ML
  1311 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1312 circumvent possible incompatibilities when working on ML level.
  1313 
  1314 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1315 
  1316 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1317 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1318 
  1319 * New syntax for Haskell-like list comprehension (input only), eg.
  1320 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1321 
  1322 * The special syntax for function "filter" has changed from [x :
  1323 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1324 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1325 
  1326 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1327 defined on nat only, as an abbreviation for [a..<Suc b]
  1328 INCOMPATIBILITY.
  1329 
  1330 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1331 
  1332 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1333 
  1334 * New lemma collection field_simps (an extension of ring_simps) for
  1335 manipulating (in)equations involving division. Multiplies with all
  1336 denominators that can be proved to be non-zero (in equations) or
  1337 positive/negative (in inequations).
  1338 
  1339 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1340 have been improved and renamed to ring_simps, group_simps and
  1341 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1342 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1343 
  1344 * Theory Library/Commutative_Ring: switched from recdef to function
  1345 package; constants add, mul, pow now curried.  Infix syntax for
  1346 algebraic operations.
  1347 
  1348 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1349 INCOMPATIBILITY.
  1350 
  1351 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1352 INCOMPATIBILITY.
  1353 
  1354 * HOL/records: generalised field-update to take a function on the
  1355 field rather than the new value: r(|A := x|) is translated to A_update
  1356 (K x) r The K-combinator that is internally used is called K_record.
  1357 INCOMPATIBILITY: Usage of the plain update functions has to be
  1358 adapted.
  1359  
  1360 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1361 * x = 0, which are required for a semiring.  Richer structures do not
  1362 inherit from semiring_0 anymore, because this property is a theorem
  1363 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1364 there is more to prove, but this is mostly trivial.
  1365 
  1366 * Class "recpower" is generalized to arbitrary monoids, not just
  1367 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1368 commutativity or semiring properties additionally.
  1369 
  1370 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1371 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1372 better use 'abbreviation'.
  1373 
  1374 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1375 
  1376 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1377 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1378 significant changes for setting up numeral syntax for types:
  1379   - New constants Numeral.pred and Numeral.succ instead
  1380       of former Numeral.bin_pred and Numeral.bin_succ.
  1381   - Use integer operations instead of bin_add, bin_mult and so on.
  1382   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1383   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1384 
  1385 See src/HOL/Integ/IntArith.thy for an example setup.
  1386 
  1387 * Command 'normal_form' computes the normal form of a term that may
  1388 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1389 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1390 heavy-duty computations because the functions are compiled to ML
  1391 first.  Correspondingly, a method "normalization" is provided.  See
  1392 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1393 
  1394 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1395 25 like -->); output depends on the "iff" print_mode, the default is
  1396 "A = B" (with priority 50).
  1397 
  1398 * Relations less (<) and less_eq (<=) are also available on type bool.
  1399 Modified syntax to disallow nesting without explicit parentheses,
  1400 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1401 INCOMPATIBILITY.
  1402 
  1403 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1404 
  1405 * Relation composition operator "op O" now has precedence 75 and binds
  1406 stronger than union and intersection. INCOMPATIBILITY.
  1407 
  1408 * The old set interval syntax "{m..n(}" (and relatives) has been
  1409 removed.  Use "{m..<n}" (and relatives) instead.
  1410 
  1411 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1412 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1413 ``declare [[simproc del: neq]]''.
  1414 
  1415 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1416 True/False.
  1417 
  1418 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1419 
  1420 * Theorem setsum_mult renamed to setsum_right_distrib.
  1421 
  1422 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1423 ``rule'' method.
  1424 
  1425 * Reimplemented methods "sat" and "satx", with several improvements:
  1426 goals no longer need to be stated as "<prems> ==> False", equivalences
  1427 (i.e. "=" on type bool) are handled, variable names of the form
  1428 "lit_<n>" are no longer reserved, significant speedup.
  1429 
  1430 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1431 zChaff is still supported as well.
  1432 
  1433 * 'inductive' and 'datatype': provide projections of mutual rules,
  1434 bundled as foo_bar.inducts;
  1435 
  1436 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1437 Library.
  1438 
  1439 * Library: moved theory Accessible_Part to main HOL.
  1440 
  1441 * Library: added theory Coinductive_List of potentially infinite lists
  1442 as greatest fixed-point.
  1443 
  1444 * Library: added theory AssocList which implements (finite) maps as
  1445 association lists.
  1446 
  1447 * Method "evaluation" solves goals (i.e. a boolean expression)
  1448 efficiently by compiling it to ML.  The goal is "proved" (via an
  1449 oracle) if it evaluates to True.
  1450 
  1451 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1452 also when invoked by the simplifier.  This results in the Simplifier
  1453 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1454 Configuration option fast_arith_split_limit=0 recovers the old
  1455 behavior.
  1456 
  1457 * Support for hex (0x20) and binary (0b1001) numerals.
  1458 
  1459 * New method: reify eqs (t), where eqs are equations for an
  1460 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1461 parameter, computes a term s::'b and a list xs::'a list and proves the
  1462 theorem I xs s = t. This is also known as reification or quoting. The
  1463 resulting theorem is applied to the subgoal to substitute t with I xs
  1464 s.  If t is omitted, the subgoal itself is reified.
  1465 
  1466 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1467 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1468 where f is supposed to be a computable function (in the sense of code
  1469 generattion). The method uses reify to compute s and xs as above then
  1470 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1471 r and finally gets the theorem t = r, which is again applied to the
  1472 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1473 
  1474 * Reflection: Automatic reification now handels binding, an example is
  1475 available in src/HOL/ex/ReflectionEx.thy
  1476 
  1477 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1478 command 'statespace' that is similar to 'record', but introduces an
  1479 abstract specification based on the locale infrastructure instead of
  1480 HOL types.  This leads to extra flexibility in composing state spaces,
  1481 in particular multiple inheritance and renaming of components.
  1482 
  1483 
  1484 *** HOL-Complex ***
  1485 
  1486 * Hyperreal: Functions root and sqrt are now defined on negative real
  1487 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1488 Nonnegativity side conditions have been removed from many lemmas, so
  1489 that more subgoals may now be solved by simplification; potential
  1490 INCOMPATIBILITY.
  1491 
  1492 * Real: new type classes formalize real normed vector spaces and
  1493 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1494 and norm :: 'a => real.
  1495 
  1496 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1497 reals into other types. The overloaded constant Reals :: 'a set is now
  1498 defined as range of_real; potential INCOMPATIBILITY.
  1499 
  1500 * Real: proper support for ML code generation, including 'quickcheck'.
  1501 Reals are implemented as arbitrary precision rationals.
  1502 
  1503 * Hyperreal: Several constants that previously worked only for the
  1504 reals have been generalized, so they now work over arbitrary vector
  1505 spaces. Type annotations may need to be added in some cases; potential
  1506 INCOMPATIBILITY.
  1507 
  1508   Infinitesimal  :: ('a::real_normed_vector) star set
  1509   HFinite        :: ('a::real_normed_vector) star set
  1510   HInfinite      :: ('a::real_normed_vector) star set
  1511   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1512   monad          :: ('a::real_normed_vector) star => 'a star set
  1513   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1514   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1515   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1516   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1517   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1518   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1519   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1520   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1521   sgn            :: 'a::real_normed_vector => 'a
  1522   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1523 
  1524 * Complex: Some complex-specific constants are now abbreviations for
  1525 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1526 hnorm.  Other constants have been entirely removed in favor of the
  1527 polymorphic versions (INCOMPATIBILITY):
  1528 
  1529   approx        <-- capprox
  1530   HFinite       <-- CFinite
  1531   HInfinite     <-- CInfinite
  1532   Infinitesimal <-- CInfinitesimal
  1533   monad         <-- cmonad
  1534   galaxy        <-- cgalaxy
  1535   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1536   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1537   (ns)deriv     <-- (ns)cderiv
  1538 
  1539 
  1540 *** HOL-Algebra ***
  1541 
  1542 * Formalisation of ideals and the quotient construction over rings.
  1543 
  1544 * Order and lattice theory no longer based on records.
  1545 INCOMPATIBILITY.
  1546 
  1547 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1548 greatest_closed.  INCOMPATIBILITY.
  1549 
  1550 * Method algebra is now set up via an attribute.  For examples see
  1551 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1552 of algebraic structures.
  1553 
  1554 * Renamed theory CRing to Ring.
  1555 
  1556 
  1557 *** HOL-Nominal ***
  1558 
  1559 * Substantial, yet incomplete support for nominal datatypes (binding
  1560 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1561 src/HOL/Nominal/Examples.  Prospective users should consult
  1562 http://isabelle.in.tum.de/nominal/
  1563 
  1564 
  1565 *** ML ***
  1566 
  1567 * ML basics: just one true type int, which coincides with IntInf.int
  1568 (even on SML/NJ).
  1569 
  1570 * ML within Isar: antiquotations allow to embed statically-checked
  1571 formal entities in the source, referring to the context available at
  1572 compile-time.  For example:
  1573 
  1574 ML {* @{sort "{zero,one}"} *}
  1575 ML {* @{typ "'a => 'b"} *}
  1576 ML {* @{term "%x. x"} *}
  1577 ML {* @{prop "x == y"} *}
  1578 ML {* @{ctyp "'a => 'b"} *}
  1579 ML {* @{cterm "%x. x"} *}
  1580 ML {* @{cprop "x == y"} *}
  1581 ML {* @{thm asm_rl} *}
  1582 ML {* @{thms asm_rl} *}
  1583 ML {* @{type_name c} *}
  1584 ML {* @{type_syntax c} *}
  1585 ML {* @{const_name c} *}
  1586 ML {* @{const_syntax c} *}
  1587 ML {* @{context} *}
  1588 ML {* @{theory} *}
  1589 ML {* @{theory Pure} *}
  1590 ML {* @{theory_ref} *}
  1591 ML {* @{theory_ref Pure} *}
  1592 ML {* @{simpset} *}
  1593 ML {* @{claset} *}
  1594 ML {* @{clasimpset} *}
  1595 
  1596 The same works for sources being ``used'' within an Isar context.
  1597 
  1598 * ML in Isar: improved error reporting; extra verbosity with
  1599 ML_Context.trace enabled.
  1600 
  1601 * Pure/General/table.ML: the join operations now works via exceptions
  1602 DUP/SAME instead of type option. This is simpler in simple cases, and
  1603 admits slightly more efficient complex applications.
  1604 
  1605 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1606 use Context.generic instead of just theory.
  1607 
  1608 * Pure: datatype Context.generic joins theory/Proof.context and
  1609 provides some facilities for code that works in either kind of
  1610 context, notably GenericDataFun for uniform theory and proof data.
  1611 
  1612 * Pure: simplified internal attribute type, which is now always
  1613 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1614 local (Proof.context) attributes have been discontinued, while
  1615 minimizing code duplication. Thm.rule_attribute and
  1616 Thm.declaration_attribute build canonical attributes; see also structure
  1617 Context for further operations on Context.generic, notably
  1618 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1619 declarations and definitions.
  1620 
  1621 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1622 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1623 init only required for impure data. INCOMPATIBILITY: empty really need
  1624 to be empty (no dependencies on theory content!)
  1625 
  1626 * Pure/kernel: consts certification ignores sort constraints given in
  1627 signature declarations. (This information is not relevant to the
  1628 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1629 potential INCOMPATIBILITY.
  1630 
  1631 * Pure: axiomatic type classes are now purely definitional, with
  1632 explicit proofs of class axioms and super class relations performed
  1633 internally. See Pure/axclass.ML for the main internal interfaces --
  1634 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1635 AxClass.axiomatize_class/classrel/arity supersede
  1636 Sign.add_classes/classrel/arities.
  1637 
  1638 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1639 global/local versions on theory vs. Proof.context have been
  1640 discontinued; Attrib.syntax and Method.syntax have been adapted
  1641 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1642 attributes, methods, etc.
  1643 
  1644 * Pure: several functions of signature "... -> theory -> theory * ..."
  1645 have been reoriented to "... -> theory -> ... * theory" in order to
  1646 allow natural usage in combination with the ||>, ||>>, |-> and
  1647 fold_map combinators.
  1648 
  1649 * Pure: official theorem names (closed derivations) and additional
  1650 comments (tags) are now strictly separate.  Name hints -- which are
  1651 maintained as tags -- may be attached any time without affecting the
  1652 derivation.
  1653 
  1654 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1655 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1656 achieve the old behaviour.
  1657 
  1658 * Pure: the "Goal" constant is now called "prop", supporting a
  1659 slightly more general idea of ``protecting'' meta-level rule
  1660 statements.
  1661 
  1662 * Pure: Logic.(un)varify only works in a global context, which is now
  1663 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1664 Logic.legacy_(un)varify as temporary workaround.
  1665 
  1666 * Pure: structure Name provides scalable operations for generating
  1667 internal variable names, notably Name.variants etc.  This replaces
  1668 some popular functions from term.ML:
  1669 
  1670   Term.variant		->  Name.variant
  1671   Term.variantlist	->  Name.variant_list
  1672   Term.invent_names	->  Name.invent_list
  1673 
  1674 Note that low-level renaming rarely occurs in new code -- operations
  1675 from structure Variable are used instead (see below).
  1676 
  1677 * Pure: structure Variable provides fundamental operations for proper
  1678 treatment of fixed/schematic variables in a context.  For example,
  1679 Variable.import introduces fixes for schematics of given facts and
  1680 Variable.export reverses the effect (up to renaming) -- this replaces
  1681 various freeze_thaw operations.
  1682 
  1683 * Pure: structure Goal provides simple interfaces for
  1684 init/conclude/finish and tactical prove operations (replacing former
  1685 Tactic.prove).  Goal.prove is the canonical way to prove results
  1686 within a given context; Goal.prove_global is a degraded version for
  1687 theory level goals, including a global Drule.standard.  Note that
  1688 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1689 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1690 in a locale context).
  1691 
  1692 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1693 and type checking (Syntax.check_term etc.), with common combinations
  1694 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1695 which are considered legacy and await removal.
  1696 
  1697 * Pure/Syntax: generic interfaces for type unchecking
  1698 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1699 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1700 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1701 available for convenience, but refer to the very same operations using
  1702 a mere theory instead of a full context.
  1703 
  1704 * Isar: simplified treatment of user-level errors, using exception
  1705 ERROR of string uniformly.  Function error now merely raises ERROR,
  1706 without any side effect on output channels.  The Isar toplevel takes
  1707 care of proper display of ERROR exceptions.  ML code may use plain
  1708 handle/can/try; cat_error may be used to concatenate errors like this:
  1709 
  1710   ... handle ERROR msg => cat_error msg "..."
  1711 
  1712 Toplevel ML code (run directly or through the Isar toplevel) may be
  1713 embedded into the Isar toplevel with exception display/debug like
  1714 this:
  1715 
  1716   Isar.toplevel (fn () => ...)
  1717 
  1718 INCOMPATIBILITY, removed special transform_error facilities, removed
  1719 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1720 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1721 -- use plain ERROR instead.
  1722 
  1723 * Isar: theory setup now has type (theory -> theory), instead of a
  1724 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1725 
  1726 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1727 ProofContext.debug/verbose flags.
  1728 
  1729 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1730 theory before entering a proof state.  Transactions now always see a
  1731 quasi-functional intermediate checkpoint, both in interactive and
  1732 batch mode.
  1733 
  1734 * Isar: simplified interfaces for outer syntax.  Renamed
  1735 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1736 OuterSyntax.add_parsers -- this functionality is now included in
  1737 OuterSyntax.command etc.  INCOMPATIBILITY.
  1738 
  1739 * Simplifier: the simpset of a running simplification process now
  1740 contains a proof context (cf. Simplifier.the_context), which is the
  1741 very context that the initial simpset has been retrieved from (by
  1742 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1743 (solver, looper etc.) may depend on arbitrary proof data.
  1744 
  1745 * Simplifier.inherit_context inherits the proof context (plus the
  1746 local bounds) of the current simplification process; any simproc
  1747 etc. that calls the Simplifier recursively should do this!  Removed
  1748 former Simplifier.inherit_bounds, which is already included here --
  1749 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1750 specify an explicit context using Simplifier.context/theory_context.
  1751 
  1752 * Simplifier/Classical Reasoner: more abstract interfaces
  1753 change_simpset/claset for modifying the simpset/claset reference of a
  1754 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1755 INCOMPATIBILITY.
  1756 
  1757 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1758 "Trueprop" etc.
  1759 
  1760 
  1761 *** System ***
  1762 
  1763 * settings: the default heap location within ISABELLE_HOME_USER now
  1764 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  1765 Isabelle installations.
  1766 
  1767 * isabelle-process: option -S (secure mode) disables some critical
  1768 operations, notably runtime compilation and evaluation of ML source
  1769 code.
  1770 
  1771 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1772 
  1773 * Support for parallel execution, using native multicore support of
  1774 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1775 independent theories, according to the given theory header
  1776 specifications. The maximum number of worker threads is specified via
  1777 usedir option -M or the "max-threads" setting in Proof General. A
  1778 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1779 to 6 on a 8-core machine.  User-code needs to observe certain
  1780 guidelines for thread-safe programming, see appendix A in the Isar
  1781 Implementation manual.
  1782 
  1783 
  1784 
  1785 New in Isabelle2005 (October 2005)
  1786 ----------------------------------
  1787 
  1788 *** General ***
  1789 
  1790 * Theory headers: the new header syntax for Isar theories is
  1791 
  1792   theory <name>
  1793   imports <theory1> ... <theoryN>
  1794   uses <file1> ... <fileM>
  1795   begin
  1796 
  1797 where the 'uses' part is optional.  The previous syntax
  1798 
  1799   theory <name> = <theory1> + ... + <theoryN>:
  1800 
  1801 will disappear in the next release.  Use isatool fixheaders to convert
  1802 existing theory files.  Note that there is no change in ancient
  1803 non-Isar theories now, but these will disappear soon.
  1804 
  1805 * Theory loader: parent theories can now also be referred to via
  1806 relative and absolute paths.
  1807 
  1808 * Command 'find_theorems' searches for a list of criteria instead of a
  1809 list of constants. Known criteria are: intro, elim, dest, name:string,
  1810 simp:term, and any term. Criteria can be preceded by '-' to select
  1811 theorems that do not match. Intro, elim, dest select theorems that
  1812 match the current goal, name:s selects theorems whose fully qualified
  1813 name contain s, and simp:term selects all simplification rules whose
  1814 lhs match term.  Any other term is interpreted as pattern and selects
  1815 all theorems matching the pattern. Available in ProofGeneral under
  1816 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1817 
  1818   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1819 
  1820 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1821 matching the current goal as introduction rule and not having "HOL."
  1822 in their name (i.e. not being defined in theory HOL).
  1823 
  1824 * Command 'thms_containing' has been discontinued in favour of
  1825 'find_theorems'; INCOMPATIBILITY.
  1826 
  1827 * Communication with Proof General is now 8bit clean, which means that
  1828 Unicode text in UTF-8 encoding may be used within theory texts (both
  1829 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1830 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1831 
  1832   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1833   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1834 
  1835 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1836 Classical Reasoner.  Typical big applications run around 2 times
  1837 faster.
  1838 
  1839 
  1840 *** Document preparation ***
  1841 
  1842 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1843 of raw sources.  Only those symbols that do not require additional
  1844 LaTeX packages (depending on comments in isabellesym.sty) are
  1845 displayed properly, everything else is left verbatim.  isatool display
  1846 and isatool print are used as front ends (these are subject to the
  1847 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1848 
  1849 * Command tags control specific markup of certain regions of text,
  1850 notably folding and hiding.  Predefined tags include "theory" (for
  1851 theory begin and end), "proof" for proof commands, and "ML" for
  1852 commands involving ML code; the additional tags "visible" and
  1853 "invisible" are unused by default.  Users may give explicit tag
  1854 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1855 interpretation of tags is determined by the LaTeX job during document
  1856 preparation: see option -V of isatool usedir, or options -n and -t of
  1857 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1858 \isadroptag.
  1859 
  1860 Several document versions may be produced at the same time via isatool
  1861 usedir (the generated index.html will link all of them).  Typical
  1862 specifications include ''-V document=theory,proof,ML'' to present
  1863 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1864 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1865 these parts without any formal replacement text.  The Isabelle site
  1866 default settings produce ''document'' and ''outline'' versions as
  1867 specified above.
  1868 
  1869 * Several new antiquotations:
  1870 
  1871   @{term_type term} prints a term with its type annotated;
  1872 
  1873   @{typeof term} prints the type of a term;
  1874 
  1875   @{const const} is the same as @{term const}, but checks that the
  1876   argument is a known logical constant;
  1877 
  1878   @{term_style style term} and @{thm_style style thm} print a term or
  1879   theorem applying a "style" to it
  1880 
  1881   @{ML text}
  1882 
  1883 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1884 definitions, equations, inequations etc., 'concl' printing only the
  1885 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1886 to print the specified premise.  TermStyle.add_style provides an ML
  1887 interface for introducing further styles.  See also the "LaTeX Sugar"
  1888 document practical applications.  The ML antiquotation prints
  1889 type-checked ML expressions verbatim.
  1890 
  1891 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1892 and 'text' support optional locale specification '(in loc)', which
  1893 specifies the default context for interpreting antiquotations.  For
  1894 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1895 
  1896 * Option 'locale=NAME' of antiquotations specifies an alternative
  1897 context interpreting the subsequent argument.  For example: @{thm
  1898 [locale=lattice] inf_assoc}.
  1899 
  1900 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1901 a proof context.
  1902 
  1903 * Proper output of antiquotations for theory commands involving a
  1904 proof context (such as 'locale' or 'theorem (in loc) ...').
  1905 
  1906 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1907 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1908 
  1909 * isatool usedir: new option -C (default true) controls whether option
  1910 -D should include a copy of the original document directory; -C false
  1911 prevents unwanted effects such as copying of administrative CVS data.
  1912 
  1913 
  1914 *** Pure ***
  1915 
  1916 * Considerably improved version of 'constdefs' command.  Now performs
  1917 automatic type-inference of declared constants; additional support for
  1918 local structure declarations (cf. locales and HOL records), see also
  1919 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1920 sequential dependencies of definitions within a single 'constdefs'
  1921 section; moreover, the declared name needs to be an identifier.  If
  1922 all fails, consider to fall back on 'consts' and 'defs' separately.
  1923 
  1924 * Improved indexed syntax and implicit structures.  First of all,
  1925 indexed syntax provides a notational device for subscripted
  1926 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1927 expressions.  Secondly, in a local context with structure
  1928 declarations, number indexes \<^sub>n or the empty index (default
  1929 number 1) refer to a certain fixed variable implicitly; option
  1930 show_structs controls printing of implicit structures.  Typical
  1931 applications of these concepts involve record types and locales.
  1932 
  1933 * New command 'no_syntax' removes grammar declarations (and
  1934 translations) resulting from the given syntax specification, which is
  1935 interpreted in the same manner as for the 'syntax' command.
  1936 
  1937 * 'Advanced' translation functions (parse_translation etc.) may depend
  1938 on the signature of the theory context being presently used for
  1939 parsing/printing, see also isar-ref manual.
  1940 
  1941 * Improved 'oracle' command provides a type-safe interface to turn an
  1942 ML expression of type theory -> T -> term into a primitive rule of
  1943 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1944 is already included here); see also FOL/ex/IffExample.thy;
  1945 INCOMPATIBILITY.
  1946 
  1947 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1948 before); "cI" is no longer bound, use "c.intro" instead.
  1949 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1950 axclasses vs. locales.
  1951 
  1952 * Improved internal renaming of symbolic identifiers -- attach primes
  1953 instead of base 26 numbers.
  1954 
  1955 * New flag show_question_marks controls printing of leading question
  1956 marks in schematic variable names.
  1957 
  1958 * In schematic variable names, *any* symbol following \<^isub> or
  1959 \<^isup> is now treated as part of the base name.  For example, the
  1960 following works without printing of awkward ".0" indexes:
  1961 
  1962   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1963     by simp
  1964 
  1965 * Inner syntax includes (*(*nested*) comments*).
  1966 
  1967 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1968 annotations as "(00...)".
  1969 
  1970 * Clear separation of logical types and nonterminals, where the latter
  1971 may only occur in 'syntax' specifications or type abbreviations.
  1972 Before that distinction was only partially implemented via type class
  1973 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1974 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1975 exotic syntax specifications may require further adaption
  1976 (e.g. Cube/Cube.thy).
  1977 
  1978 * Removed obsolete type class "logic", use the top sort {} instead.
  1979 Note that non-logical types should be declared as 'nonterminals'
  1980 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1981 specifications.
  1982 
  1983 * Attributes 'induct' and 'cases': type or set names may now be
  1984 locally fixed variables as well.
  1985 
  1986 * Simplifier: can now control the depth to which conditional rewriting
  1987 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1988 Limit.
  1989 
  1990 * Simplifier: simplification procedures may now take the current
  1991 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1992 interface), which is very useful for calling the Simplifier
  1993 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1994 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1995 low-level mk_simproc no longer applies Logic.varify internally, to
  1996 allow for use in a context of fixed variables.
  1997 
  1998 * thin_tac now works even if the assumption being deleted contains !!
  1999 or ==>.  More generally, erule now works even if the major premise of
  2000 the elimination rule contains !! or ==>.
  2001 
  2002 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2003 
  2004 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2005 from Pure, which contains all common declarations already.  Both
  2006 theories are defined via plain Isabelle/Isar .thy files.
  2007 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2008 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2009 use isatool fixcpure to adapt your theory and ML sources.
  2010 
  2011 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2012 selections of theorems in named facts via index ranges.
  2013 
  2014 * 'print_theorems': in theory mode, really print the difference
  2015 wrt. the last state (works for interactive theory development only),
  2016 in proof mode print all local facts (cf. 'print_facts');
  2017 
  2018 * 'hide': option '(open)' hides only base names.
  2019 
  2020 * More efficient treatment of intermediate checkpoints in interactive
  2021 theory development.
  2022 
  2023 * Code generator is now invoked via code_module (incremental code
  2024 generation) and code_library (modular code generation, ML structures
  2025 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2026 must be quoted when used as identifiers.
  2027 
  2028 * New 'value' command for reading, evaluating and printing terms using
  2029 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2030 quoted when used as identifier.
  2031 
  2032 
  2033 *** Locales ***
  2034 
  2035 * New commands for the interpretation of locale expressions in
  2036 theories (1), locales (2) and proof contexts (3).  These generate
  2037 proof obligations from the expression specification.  After the
  2038 obligations have been discharged, theorems of the expression are added
  2039 to the theory, target locale or proof context.  The synopsis of the
  2040 commands is a follows:
  2041 
  2042   (1) interpretation expr inst
  2043   (2) interpretation target < expr
  2044   (3) interpret expr inst
  2045 
  2046 Interpretation in theories and proof contexts require a parameter
  2047 instantiation of terms from the current context.  This is applied to
  2048 specifications and theorems of the interpreted expression.
  2049 Interpretation in locales only permits parameter renaming through the
  2050 locale expression.  Interpretation is smart in that interpretations
  2051 that are active already do not occur in proof obligations, neither are
  2052 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2053 inspect active interpretations of a particular locale.  For details,
  2054 see the Isar Reference manual.  Examples can be found in
  2055 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2056 
  2057 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2058 'interpret' instead.
  2059 
  2060 * New context element 'constrains' for adding type constraints to
  2061 parameters.
  2062 
  2063 * Context expressions: renaming of parameters with syntax
  2064 redeclaration.
  2065 
  2066 * Locale declaration: 'includes' disallowed.
  2067 
  2068 * Proper static binding of attribute syntax -- i.e. types / terms /
  2069 facts mentioned as arguments are always those of the locale definition
  2070 context, independently of the context of later invocations.  Moreover,
  2071 locale operations (renaming and type / term instantiation) are applied
  2072 to attribute arguments as expected.
  2073 
  2074 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2075 actual attributes; rare situations may require Attrib.attribute to
  2076 embed those attributes into Attrib.src that lack concrete syntax.
  2077 Attribute implementations need to cooperate properly with the static
  2078 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2079 Attrib.XXX_thm etc. already do the right thing without further
  2080 intervention.  Only unusual applications -- such as "where" or "of"
  2081 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2082 on the context and the facts involved -- may have to assign parsed
  2083 values to argument tokens explicitly.
  2084 
  2085 * Changed parameter management in theorem generation for long goal
  2086 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2087 theorem statement in rare situations.
  2088 
  2089 * Locale inspection command 'print_locale' omits notes elements.  Use
  2090 'print_locale!' to have them included in the output.
  2091 
  2092 
  2093 *** Provers ***
  2094 
  2095 * Provers/hypsubst.ML: improved version of the subst method, for
  2096 single-step rewriting: it now works in bound variable contexts. New is
  2097 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2098 rewrite a different subterm than the original subst method, which is
  2099 still available as 'simplesubst'.
  2100 
  2101 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2102 and quasi orders.
  2103 
  2104 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2105 reflexive-transitive closure of relations.
  2106 
  2107 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2108 limit (previously hard-coded with a value of 20) user-definable.
  2109 
  2110 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2111 is peformed already.  Object-logics merely need to finish their
  2112 initial simpset configuration as before.  INCOMPATIBILITY.
  2113 
  2114 
  2115 *** HOL ***
  2116 
  2117 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2118 
  2119   syntax (epsilon)
  2120     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2121 
  2122 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2123 and x-symbol; use option '-m epsilon' to get it actually printed.
  2124 Moreover, the mathematically important symbolic identifier \<epsilon>
  2125 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2126 
  2127 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2128 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2129 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2130 support corresponding Isar calculations.
  2131 
  2132 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2133 instead of ":".
  2134 
  2135 * theory SetInterval: changed the syntax for open intervals:
  2136 
  2137   Old       New
  2138   {..n(}    {..<n}
  2139   {)n..}    {n<..}
  2140   {m..n(}   {m..<n}
  2141   {)m..n}   {m<..n}
  2142   {)m..n(}  {m<..<n}
  2143 
  2144 The old syntax is still supported but will disappear in the next
  2145 release.  For conversion use the following Emacs search and replace
  2146 patterns (these are not perfect but work quite well):
  2147 
  2148   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2149   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2150 
  2151 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2152 equalities in commutative rings; method 'algebra' provides a generic
  2153 interface.
  2154 
  2155 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2156 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2157 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2158 be a tuple pattern.
  2159 
  2160 Some new syntax forms are available:
  2161 
  2162   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2163   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2164   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2165   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2166 
  2167 The latter form "\<Sum>x < k. e" used to be based on a separate
  2168 function "Summation", which has been discontinued.
  2169 
  2170 * theory Finite_Set: in structured induction proofs, the insert case
  2171 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2172 (insert F x)'.
  2173 
  2174 * The 'refute' command has been extended to support a much larger
  2175 fragment of HOL, including axiomatic type classes, constdefs and
  2176 typedefs, inductive datatypes and recursion.
  2177 
  2178 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2179 Requires zChaff with proof generation to be installed.  See
  2180 HOL/ex/SAT_Examples.thy for examples.
  2181 
  2182 * Datatype induction via method 'induct' now preserves the name of the
  2183 induction variable. For example, when proving P(xs::'a list) by
  2184 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2185 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2186 in unstructured proof scripts.
  2187 
  2188 * Reworked implementation of records.  Improved scalability for
  2189 records with many fields, avoiding performance problems for type
  2190 inference. Records are no longer composed of nested field types, but
  2191 of nested extension types. Therefore the record type only grows linear
  2192 in the number of extensions and not in the number of fields.  The
  2193 top-level (users) view on records is preserved.  Potential
  2194 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2195 old record representation. The type generated for a record is called
  2196 <record_name>_ext_type.
  2197 
  2198 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2199 proofs triggered by a record definition or a simproc (if
  2200 quick_and_dirty is enabled).  Definitions of large records can take
  2201 quite long.
  2202 
  2203 New simproc record_upd_simproc for simplification of multiple record
  2204 updates enabled by default.  Moreover, trivial updates are also
  2205 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2206 occasionally, since simplification is more powerful by default.
  2207 
  2208 * typedef: proper support for polymorphic sets, which contain extra
  2209 type-variables in the term.
  2210 
  2211 * Simplifier: automatically reasons about transitivity chains
  2212 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2213 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2214 old proofs break occasionally as simplification may now solve more
  2215 goals than previously.
  2216 
  2217 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2218 present.  Works for all partial orders (class "order"), in particular
  2219 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2220 just like y <= x.
  2221 
  2222 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2223 bound variable or a constant then the let is unfolded.  Otherwise
  2224 first a is simplified to b, and then f b is simplified to g. If
  2225 possible we abstract b from g arriving at "let x = b in h x",
  2226 otherwise we unfold the let and arrive at g.  The simproc can be
  2227 enabled/disabled by the reference use_let_simproc.  Potential
  2228 INCOMPATIBILITY since simplification is more powerful by default.
  2229 
  2230 * Classical reasoning: the meson method now accepts theorems as arguments.
  2231 
  2232 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2233 jobs to provide advice on the provability of subgoals.
  2234 
  2235 * Theory OrderedGroup and Ring_and_Field: various additions and
  2236 improvements to faciliate calculations involving equalities and
  2237 inequalities.
  2238 
  2239 The following theorems have been eliminated or modified
  2240 (INCOMPATIBILITY):
  2241 
  2242   abs_eq             now named abs_of_nonneg
  2243   abs_of_ge_0        now named abs_of_nonneg
  2244   abs_minus_eq       now named abs_of_nonpos
  2245   imp_abs_id         now named abs_of_nonneg
  2246   imp_abs_neg_id     now named abs_of_nonpos
  2247   mult_pos           now named mult_pos_pos
  2248   mult_pos_le        now named mult_nonneg_nonneg
  2249   mult_pos_neg_le    now named mult_nonneg_nonpos
  2250   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2251   mult_neg           now named mult_neg_neg
  2252   mult_neg_le        now named mult_nonpos_nonpos
  2253 
  2254 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2255      
  2256      zero_le_square
  2257      not_square_less_zero 
  2258 
  2259   The following lemmas have been deleted from Real/RealPow:
  2260   
  2261      realpow_zero_zero
  2262      realpow_two
  2263      realpow_less
  2264      zero_le_power
  2265      realpow_two_le
  2266      abs_realpow_two
  2267      realpow_two_abs     
  2268 
  2269 * Theory Parity: added rules for simplifying exponents.
  2270 
  2271 * Theory List:
  2272 
  2273 The following theorems have been eliminated or modified
  2274 (INCOMPATIBILITY):
  2275 
  2276   list_all_Nil       now named list_all.simps(1)
  2277   list_all_Cons      now named list_all.simps(2)
  2278   list_all_conv      now named list_all_iff
  2279   set_mem_eq         now named mem_iff
  2280 
  2281 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2282 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2283 
  2284 
  2285 *** HOL-Complex ***
  2286 
  2287 * Theory RealDef: better support for embedding natural numbers and
  2288 integers in the reals.
  2289 
  2290 The following theorems have been eliminated or modified
  2291 (INCOMPATIBILITY):
  2292 
  2293   exp_ge_add_one_self  now requires no hypotheses
  2294   real_of_int_add      reversed direction of equality (use [symmetric])
  2295   real_of_int_minus    reversed direction of equality (use [symmetric])
  2296   real_of_int_diff     reversed direction of equality (use [symmetric])
  2297   real_of_int_mult     reversed direction of equality (use [symmetric])
  2298 
  2299 * Theory RComplete: expanded support for floor and ceiling functions.
  2300 
  2301 * Theory Ln is new, with properties of the natural logarithm
  2302 
  2303 * Hyperreal: There is a new type constructor "star" for making
  2304 nonstandard types.  The old type names are now type synonyms:
  2305 
  2306   hypreal = real star
  2307   hypnat = nat star
  2308   hcomplex = complex star
  2309 
  2310 * Hyperreal: Many groups of similarly-defined constants have been
  2311 replaced by polymorphic versions (INCOMPATIBILITY):
  2312 
  2313   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2314 
  2315   starset      <-- starsetNat, starsetC
  2316   *s*          <-- *sNat*, *sc*
  2317   starset_n    <-- starsetNat_n, starsetC_n
  2318   *sn*         <-- *sNatn*, *scn*
  2319   InternalSets <-- InternalNatSets, InternalCSets
  2320 
  2321   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2322   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2323   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2324   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2325   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2326 
  2327 * Hyperreal: Many type-specific theorems have been removed in favor of
  2328 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2329 
  2330   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2331   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2332   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2333   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2334   right_minus <-- hypreal_add_minus
  2335   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2336   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2337   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2338   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2339   mult_1_right <-- hcomplex_mult_one_right
  2340   mult_zero_left <-- hcomplex_mult_zero_left
  2341   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2342   right_distrib <-- hypnat_add_mult_distrib2
  2343   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2344   right_inverse <-- hypreal_mult_inverse
  2345   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2346   order_refl <-- {hypreal,hypnat}_le_refl
  2347   order_trans <-- {hypreal,hypnat}_le_trans
  2348   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2349   order_less_le <-- {hypreal,hypnat}_less_le
  2350   linorder_linear <-- {hypreal,hypnat}_le_linear
  2351   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2352   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2353   add_nonneg_nonneg <-- hypreal_le_add_order
  2354 
  2355 * Hyperreal: Separate theorems having to do with type-specific
  2356 versions of constants have been merged into theorems that apply to the
  2357 new polymorphic constants (INCOMPATIBILITY):
  2358 
  2359   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2360   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2361   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2362   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2363   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2364   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2365   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2366   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2367   STAR_diff <-- {STAR,STARC}_diff
  2368   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2369     STARC_hcomplex_of_complex}_image_subset
  2370   starset_n_Un <-- starset{Nat,C}_n_Un
  2371   starset_n_Int <-- starset{Nat,C}_n_Int
  2372   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2373   starset_n_diff <-- starset{Nat,C}_n_diff
  2374   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2375   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2376   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2377   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2378   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2379   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2380   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2381   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2382   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2383   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2384   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2385   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2386   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2387   starfun_diff <-- starfun{C,RC,CR}_diff
  2388   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2389   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2390   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2391   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2392   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2393   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2394   starfun_Id <-- starfunC_Id
  2395   starfun_approx <-- starfun{Nat,CR}_approx
  2396   starfun_capprox <-- starfun{C,RC}_capprox
  2397   starfun_abs <-- starfunNat_rabs
  2398   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2399   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2400   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2401   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2402   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2403   starfun_add_approx <-- starfunCR_add_approx
  2404   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2405   starfun_divide <-- starfun{C,CR,RC}_divide
  2406   starfun_n <-- starfun{Nat,C}_n
  2407   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2408   starfun_n_add <-- starfun{Nat,C}_n_add
  2409   starfun_n_add_minus <-- starfunNat_n_add_minus
  2410   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2411   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2412   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2413 
  2414   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2415   star_n_minus <-- {hypreal,hcomplex}_minus
  2416   star_n_diff <-- {hypreal,hcomplex}_diff
  2417   star_n_mult <-- {hypreal,hcomplex}_mult
  2418   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2419   star_n_le <-- {hypreal,hypnat}_le
  2420   star_n_less <-- {hypreal,hypnat}_less
  2421   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2422   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2423   star_n_abs <-- hypreal_hrabs
  2424   star_n_divide <-- hcomplex_divide
  2425 
  2426   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2427   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2428   star_of_diff <-- hypreal_of_real_diff
  2429   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2430   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2431   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2432   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2433   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2434   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2435   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2436   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2437   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2438   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2439   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2440   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2441   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2442   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2443   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2444   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2445   star_of_power <-- hypreal_of_real_power
  2446   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2447 
  2448 * Hyperreal: new method "transfer" that implements the transfer
  2449 principle of nonstandard analysis. With a subgoal that mentions
  2450 nonstandard types like "'a star", the command "apply transfer"
  2451 replaces it with an equivalent one that mentions only standard types.
  2452 To be successful, all free variables must have standard types; non-
  2453 standard variables must have explicit universal quantifiers.
  2454 
  2455 * Hyperreal: A theory of Taylor series.
  2456 
  2457 
  2458 *** HOLCF ***
  2459 
  2460 * Discontinued special version of 'constdefs' (which used to support
  2461 continuous functions) in favor of the general Pure one with full
  2462 type-inference.
  2463 
  2464 * New simplification procedure for solving continuity conditions; it
  2465 is much faster on terms with many nested lambda abstractions (cubic
  2466 instead of exponential time).
  2467 
  2468 * New syntax for domain package: selector names are now optional.
  2469 Parentheses should be omitted unless argument is lazy, for example:
  2470 
  2471   domain 'a stream = cons "'a" (lazy "'a stream")
  2472 
  2473 * New command 'fixrec' for defining recursive functions with pattern
  2474 matching; defining multiple functions with mutual recursion is also
  2475 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2476 sinr, or any data constructor defined by the domain package. The given
  2477 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2478 syntax and examples.
  2479 
  2480 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2481 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2482 but the proof obligation additionally includes an admissibility
  2483 requirement. The packages generate instances of class cpo or pcpo,
  2484 with continuity and strictness theorems for Rep and Abs.
  2485 
  2486 * HOLCF: Many theorems have been renamed according to a more standard naming
  2487 scheme (INCOMPATIBILITY):
  2488 
  2489   foo_inject:  "foo$x = foo$y ==> x = y"
  2490   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2491   foo_less:    "(foo$x << foo$y) = (x << y)"
  2492   foo_strict:  "foo$UU = UU"
  2493   foo_defined: "... ==> foo$x ~= UU"
  2494   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2495 
  2496 
  2497 *** ZF ***
  2498 
  2499 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2500 including the First Isomorphism Theorem (on quotienting by the kernel
  2501 of a homomorphism).
  2502 
  2503 * ZF/Simplifier: install second copy of type solver that actually
  2504 makes use of TC rules declared to Isar proof contexts (or locales);
  2505 the old version is still required for ML proof scripts.
  2506 
  2507 
  2508 *** Cube ***
  2509 
  2510 * Converted to Isar theory format; use locales instead of axiomatic
  2511 theories.
  2512 
  2513 
  2514 *** ML ***
  2515 
  2516 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2517 for ||>, ||>>, |>>,
  2518 
  2519 * Pure/library.ML no longer defines its own option datatype, but uses
  2520 that of the SML basis, which has constructors NONE and SOME instead of
  2521 None and Some, as well as exception Option.Option instead of OPTION.
  2522 The functions the, if_none, is_some, is_none have been adapted
  2523 accordingly, while Option.map replaces apsome.
  2524 
  2525 * Pure/library.ML: the exception LIST has been given up in favour of
  2526 the standard exceptions Empty and Subscript, as well as
  2527 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2528 superceded by the standard hd and tl functions etc.
  2529 
  2530 A number of basic list functions are no longer exported to the ML
  2531 toplevel, as they are variants of predefined functions.  The following
  2532 suggests how one can translate existing code:
  2533 
  2534     rev_append xs ys = List.revAppend (xs, ys)
  2535     nth_elem (i, xs) = List.nth (xs, i)
  2536     last_elem xs = List.last xs
  2537     flat xss = List.concat xss
  2538     seq fs = List.app fs
  2539     partition P xs = List.partition P xs
  2540     mapfilter f xs = List.mapPartial f xs
  2541 
  2542 * Pure/library.ML: several combinators for linear functional
  2543 transformations, notably reverse application and composition:
  2544 
  2545   x |> f                f #> g
  2546   (x, y) |-> f          f #-> g
  2547 
  2548 * Pure/library.ML: introduced/changed precedence of infix operators:
  2549 
  2550   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2551   infix 2 ?;
  2552   infix 3 o oo ooo oooo;
  2553   infix 4 ~~ upto downto;
  2554 
  2555 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2556 infix operators.
  2557 
  2558 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2559 fold_map support linear functional transformations and nesting.  For
  2560 example:
  2561 
  2562   fold f [x1, ..., xN] y =
  2563     y |> f x1 |> ... |> f xN
  2564 
  2565   (fold o fold) f [xs1, ..., xsN] y =
  2566     y |> fold f xs1 |> ... |> fold f xsN
  2567 
  2568   fold f [x1, ..., xN] =
  2569     f x1 #> ... #> f xN
  2570 
  2571   (fold o fold) f [xs1, ..., xsN] =
  2572     fold f xs1 #> ... #> fold f xsN
  2573 
  2574 * Pure/library.ML: the following selectors on type 'a option are
  2575 available:
  2576 
  2577   the:               'a option -> 'a  (*partial*)
  2578   these:             'a option -> 'a  where 'a = 'b list
  2579   the_default: 'a -> 'a option -> 'a
  2580   the_list:          'a option -> 'a list
  2581 
  2582 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2583 basic operations for association lists, following natural argument
  2584 order; moreover the explicit equality predicate passed here avoids
  2585 potentially expensive polymorphic runtime equality checks.
  2586 The old functions may be expressed as follows:
  2587 
  2588   assoc = uncurry (AList.lookup (op =))
  2589   assocs = these oo AList.lookup (op =)
  2590   overwrite = uncurry (AList.update (op =)) o swap
  2591 
  2592 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2593 
  2594   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2595   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2596 
  2597 replacing make_keylist and keyfilter (occassionally used)
  2598 Naive rewrites:
  2599 
  2600   make_keylist = AList.make
  2601   keyfilter = AList.find (op =)
  2602 
  2603 * eq_fst and eq_snd now take explicit equality parameter, thus
  2604   avoiding eqtypes. Naive rewrites:
  2605 
  2606     eq_fst = eq_fst (op =)
  2607     eq_snd = eq_snd (op =)
  2608 
  2609 * Removed deprecated apl and apr (rarely used).
  2610   Naive rewrites:
  2611 
  2612     apl (n, op) =>>= curry op n
  2613     apr (op, m) =>>= fn n => op (n, m)
  2614 
  2615 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2616 provides a reasonably efficient light-weight implementation of sets as
  2617 lists.
  2618 
  2619 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2620 few new operations; existing lookup and update are now curried to
  2621 follow natural argument order (for use with fold etc.);
  2622 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2623 
  2624 * Pure/General: output via the Isabelle channels of
  2625 writeln/warning/error etc. is now passed through Output.output, with a
  2626 hook for arbitrary transformations depending on the print_mode
  2627 (cf. Output.add_mode -- the first active mode that provides a output
  2628 function wins).  Already formatted output may be embedded into further
  2629 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2630 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2631 accommodate easy composition of diagnostic messages etc.  Programmers
  2632 rarely need to care about Output.output or Output.raw at all, with
  2633 some notable exceptions: Output.output is required when bypassing the
  2634 standard channels (writeln etc.), or in token translations to produce
  2635 properly formatted results; Output.raw is required when capturing
  2636 already output material that will eventually be presented to the user
  2637 a second time.  For the default print mode, both Output.output and
  2638 Output.raw have no effect.
  2639 
  2640 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2641 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2642 cumulative results are displayed at the end of a batch session.
  2643 
  2644 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2645 replaced by File.platform_path and File.shell_path (with appropriate
  2646 hooks).  This provides a clean interface for unusual systems where the
  2647 internal and external process view of file names are different.
  2648 
  2649 * Pure: more efficient orders for basic syntactic entities: added
  2650 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2651 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2652 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2653 orders now -- potential INCOMPATIBILITY for code that depends on a
  2654 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2655 Library.sort_strings on result).
  2656 
  2657 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2658 fold_types traverse types/terms from left to right, observing natural
  2659 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2660 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2661 
  2662 * Pure: name spaces have been refined, with significant changes of the
  2663 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2664 to extern(_table).  The plain name entry path is superceded by a
  2665 general 'naming' context, which also includes the 'policy' to produce
  2666 a fully qualified name and external accesses of a fully qualified
  2667 name; NameSpace.extend is superceded by context dependent
  2668 Sign.declare_name.  Several theory and proof context operations modify
  2669 the naming context.  Especially note Theory.restore_naming and
  2670 ProofContext.restore_naming to get back to a sane state; note that
  2671 Theory.add_path is no longer sufficient to recover from
  2672 Theory.absolute_path in particular.
  2673 
  2674 * Pure: new flags short_names (default false) and unique_names
  2675 (default true) for controlling output of qualified names.  If
  2676 short_names is set, names are printed unqualified.  If unique_names is
  2677 reset, the name prefix is reduced to the minimum required to achieve
  2678 the original result when interning again, even if there is an overlap
  2679 with earlier declarations.
  2680 
  2681 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2682 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2683 (useful for printing error messages).  INCOMPATIBILITY.
  2684 
  2685 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2686 Theory.theory are now identified, referring to the universal
  2687 Context.theory (see Pure/context.ML).  Actual signature and theory
  2688 content is managed as theory data.  The old code and interfaces were
  2689 spread over many files and structures; the new arrangement introduces
  2690 considerable INCOMPATIBILITY to gain more clarity:
  2691 
  2692   Context -- theory management operations (name, identity, inclusion,
  2693     parents, ancestors, merge, etc.), plus generic theory data;
  2694 
  2695   Sign -- logical signature and syntax operations (declaring consts,
  2696     types, etc.), plus certify/read for common entities;
  2697 
  2698   Theory -- logical theory operations (stating axioms, definitions,
  2699     oracles), plus a copy of logical signature operations (consts,
  2700     types, etc.); also a few basic management operations (Theory.copy,
  2701     Theory.merge, etc.)
  2702 
  2703 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2704 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2705 for convenience -- they merely return the theory.
  2706 
  2707 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2708 
  2709 * Pure: the Isar proof context type is already defined early in Pure
  2710 as Context.proof (note that ProofContext.context and Proof.context are
  2711 aliases, where the latter is the preferred name).  This enables other
  2712 Isabelle components to refer to that type even before Isar is present.
  2713 
  2714 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2715 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2716 any of these kinds.  For example, Sign.intern typeK is now
  2717 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2718 Theory.hide_types.  Also note that former
  2719 Theory.hide_classes/types/consts are now
  2720 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2721 internalize their arguments!  INCOMPATIBILITY.
  2722 
  2723 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2724 datatype thmref (with constructors Name and NameSelection) instead of
  2725 plain string -- INCOMPATIBILITY;
  2726 
  2727 * Pure: cases produced by proof methods specify options, where NONE
  2728 means to remove case bindings -- INCOMPATIBILITY in
  2729 (RAW_)METHOD_CASES.
  2730 
  2731 * Pure: the following operations retrieve axioms or theorems from a
  2732 theory node or theory hierarchy, respectively:
  2733 
  2734   Theory.axioms_of: theory -> (string * term) list
  2735   Theory.all_axioms_of: theory -> (string * term) list
  2736   PureThy.thms_of: theory -> (string * thm) list
  2737   PureThy.all_thms_of: theory -> (string * thm) list
  2738 
  2739 * Pure: print_tac now outputs the goal through the trace channel.
  2740 
  2741 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2742 Reference Toplevel.debug (default false) controls detailed printing
  2743 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2744 controls execution profiling -- set to 1 for time and 2 for space
  2745 (both increase the runtime).
  2746 
  2747 * Isar session: The initial use of ROOT.ML is now always timed,
  2748 i.e. the log will show the actual process times, in contrast to the
  2749 elapsed wall-clock time that the outer shell wrapper produces.
  2750 
  2751 * Simplifier: improved handling of bound variables (nameless
  2752 representation, avoid allocating new strings).  Simprocs that invoke
  2753 the Simplifier recursively should use Simplifier.inherit_bounds to
  2754 avoid local name clashes.  Failure to do so produces warnings
  2755 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2756 for further details.
  2757 
  2758 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2759 bindings for all theorems stored within a given theory; this may help
  2760 in porting non-Isar theories to Isar ones, while keeping ML proof
  2761 scripts for the time being.
  2762 
  2763 * ML operator HTML.with_charset specifies the charset begin used for
  2764 generated HTML files.  For example:
  2765 
  2766   HTML.with_charset "utf-8" use_thy "Hebrew";
  2767   HTML.with_charset "utf-8" use_thy "Chinese";
  2768 
  2769 
  2770 *** System ***
  2771 
  2772 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2773 isabelle, isatool etc.).
  2774 
  2775 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2776 isatool doc, isatool mkdir, display_drafts etc.).
  2777 
  2778 * isatool usedir: option -f allows specification of the ML file to be
  2779 used by Isabelle; default is ROOT.ML.
  2780 
  2781 * New isatool version outputs the version identifier of the Isabelle
  2782 distribution being used.
  2783 
  2784 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2785 (containing Boolean satisfiability problems) into Isabelle/HOL
  2786 theories.
  2787 
  2788 
  2789 
  2790 New in Isabelle2004 (April 2004)
  2791 --------------------------------
  2792 
  2793 *** General ***
  2794 
  2795 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2796   Replaces linorder.ML.
  2797 
  2798 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2799   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2800   (\<a>...\<z>), are now considered normal letters, and can therefore
  2801   be used anywhere where an ASCII letter (a...zA...Z) has until
  2802   now. COMPATIBILITY: This obviously changes the parsing of some
  2803   terms, especially where a symbol has been used as a binder, say
  2804   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2805   as an identifier.  Fix it by inserting a space around former
  2806   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2807   existing theory and ML files.
  2808 
  2809 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2810 
  2811 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2812   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2813   a normal (but invisible) letter. For multiple letter subscripts repeat
  2814   \<^isub> like this: x\<^isub>1\<^isub>2.
  2815 
  2816 * Pure: There are now sub-/superscripts that can span more than one
  2817   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2818   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2819   superscript. The new control characters are not identifier parts.
  2820 
  2821 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2822   content of "..." to the latex file instead of \isacntrl... . The "..."
  2823   may consist of any printable characters excluding the end bracket >.
  2824 
  2825 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2826   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2827   declare constants "final", which prevents their being given a definition
  2828   later.  It is useful for constants whose behaviour is fixed axiomatically
  2829   rather than definitionally, such as the meta-logic connectives.
  2830 
  2831 * Pure: 'instance' now handles general arities with general sorts
  2832   (i.e. intersections of classes),
  2833 
  2834 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2835   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2836   It can be changed to alter the colors/layout of generated pages.
  2837 
  2838 
  2839 *** Isar ***
  2840 
  2841 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2842   cut_tac, subgoal_tac and thin_tac:
  2843   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2844     locales are no longer forced to write Isar proof scripts.
  2845     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2846     emulations.
  2847   - INCOMPATIBILITY: names of variables to be instantiated may no
  2848     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2849     This is consistent with the instantiation attribute "where".
  2850 
  2851 * Attributes "where" and "of":
  2852   - Now take type variables of instantiated theorem into account when reading
  2853     the instantiation string.  This fixes a bug that caused instantiated
  2854     theorems to have too special types in some circumstances.
  2855   - "where" permits explicit instantiations of type variables.
  2856 
  2857 * Calculation commands "moreover" and "also" no longer interfere with
  2858   current facts ("this"), admitting arbitrary combinations with "then"
  2859   and derived forms.
  2860 
  2861 * Locales:
  2862   - Goal statements involving the context element "includes" no longer
  2863     generate theorems with internal delta predicates (those ending on
  2864     "_axioms") in the premise.
  2865     Resolve particular premise with <locale>.intro to obtain old form.
  2866   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2867     specification and "includes" elements in goal statement.
  2868   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2869     [intro?] and [elim?] (respectively) by default.
  2870   - Experimental command for instantiation of locales in proof contexts:
  2871         instantiate <label>[<attrs>]: <loc>
  2872     Instantiates locale <loc> and adds all its theorems to the current context
  2873     taking into account their attributes.  Label and attrs are optional
  2874     modifiers, like in theorem declarations.  If present, names of
  2875     instantiated theorems are qualified with <label>, and the attributes
  2876     <attrs> are applied after any attributes these theorems might have already.
  2877       If the locale has assumptions, a chained fact of the form
  2878     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2879     are derived.  The command does not support old-style locales declared
  2880     with "locale (open)".
  2881       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2882 
  2883 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2884   (Isar) contexts.
  2885 
  2886 
  2887 *** HOL ***
  2888 
  2889 * Proof import: new image HOL4 contains the imported library from
  2890   the HOL4 system with about 2500 theorems. It is imported by
  2891   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2892   can be used like any other Isabelle image.  See
  2893   HOL/Import/HOL/README for more information.
  2894 
  2895 * Simplifier:
  2896   - Much improved handling of linear and partial orders.
  2897     Reasoners for linear and partial orders are set up for type classes
  2898     "linorder" and "order" respectively, and are added to the default simpset
  2899     as solvers.  This means that the simplifier can build transitivity chains
  2900     to solve goals from the assumptions.
  2901   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2902     of blast or auto after simplification become unnecessary because the goal
  2903     is solved by simplification already.
  2904 
  2905 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2906     all proved in axiomatic type classes for semirings, rings and fields.
  2907 
  2908 * Numerics:
  2909   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2910     now formalized using the Ring_and_Field theory mentioned above.
  2911   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2912     than before, because now they are set up once in a generic manner.
  2913   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2914     Look for the general versions in Ring_and_Field (and Power if they concern
  2915     exponentiation).
  2916 
  2917 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2918 
  2919 * Records:
  2920   - Record types are now by default printed with their type abbreviation
  2921     instead of the list of all field types. This can be configured via
  2922     the reference "print_record_type_abbr".
  2923   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2924     (not enabled by default).
  2925   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2926     EX x. x = sel r to True (not enabled by default).
  2927   - Tactic "record_split_simp_tac" to split and simplify records added.
  2928 
  2929 * 'specification' command added, allowing for definition by
  2930   specification.  There is also an 'ax_specification' command that
  2931   introduces the new constants axiomatically.
  2932 
  2933 * arith(_tac) is now able to generate counterexamples for reals as well.
  2934 
  2935 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2936 
  2937 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2938   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2939 
  2940 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2941   matrix theory to linear programming.
  2942 
  2943 * Unions and Intersections:
  2944   The latex output syntax of UN and INT has been changed
  2945   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2946   i.e. the index formulae has become a subscript.
  2947   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2948 
  2949 * Unions and Intersections over Intervals:
  2950   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2951   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2952   like in normal math, and corresponding versions for < and for intersection.
  2953 
  2954 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2955   lexicographic dictonary ordering has been added as "lexord".
  2956 
  2957 * ML: the legacy theory structures Int and List have been removed. They had
  2958   conflicted with ML Basis Library structures having the same names.
  2959 
  2960 * 'refute' command added to search for (finite) countermodels.  Only works
  2961   for a fragment of HOL.  The installation of an external SAT solver is
  2962   highly recommended.  See "HOL/Refute.thy" for details.
  2963 
  2964 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2965   formulae under an assignment of free variables to random values.
  2966   In contrast to 'refute', it can deal with inductive datatypes,
  2967   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2968   for examples.
  2969 
  2970 
  2971 *** HOLCF ***
  2972 
  2973 * Streams now come with concatenation and are part of the HOLCF image
  2974 
  2975 
  2976 
  2977 New in Isabelle2003 (May 2003)
  2978 ------------------------------
  2979 
  2980 *** General ***
  2981 
  2982 * Provers/simplifier:
  2983 
  2984   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2985     Assumptions are now subject to complete mutual simplification,
  2986     not just from left to right. The simplifier now preserves
  2987     the order of assumptions.
  2988 
  2989     Potential INCOMPATIBILITY:
  2990 
  2991     -- simp sometimes diverges where the old version did
  2992        not, e.g. invoking simp on the goal
  2993 
  2994         [| P (f x); y = x; f x = f y |] ==> Q
  2995 
  2996        now gives rise to the infinite reduction sequence
  2997 
  2998         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2999 
  3000        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3001        kind of problem.
  3002 
  3003     -- Tactics combining classical reasoner and simplification (such as auto)
  3004        are also affected by this change, because many of them rely on
  3005        simp. They may sometimes diverge as well or yield a different numbers
  3006        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3007        in case of problems. Sometimes subsequent calls to the classical
  3008        reasoner will fail because a preceeding call to the simplifier too
  3009        eagerly simplified the goal, e.g. deleted redundant premises.
  3010 
  3011   - The simplifier trace now shows the names of the applied rewrite rules
  3012 
  3013   - You can limit the number of recursive invocations of the simplifier
  3014     during conditional rewriting (where the simplifie tries to solve the
  3015     conditions before applying the rewrite rule):
  3016     ML "simp_depth_limit := n"
  3017     where n is an integer. Thus you can force termination where previously
  3018     the simplifier would diverge.
  3019 
  3020   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3021 
  3022   - No longer aborts on failed congruence proof.  Instead, the
  3023     congruence is ignored.
  3024 
  3025 * Pure: New generic framework for extracting programs from constructive
  3026   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3027   as HOL/Extraction for some case studies.
  3028 
  3029 * Pure: The main goal of the proof state is no longer shown by default, only
  3030 the subgoals. This behaviour is controlled by a new flag.
  3031    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3032 (ML: Proof.show_main_goal).
  3033 
  3034 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3035 rules whose conclusion matches subgoal 1:
  3036       PG menu: Isabelle/Isar -> Show me -> matching rules
  3037 The rules are ordered by how closely they match the subgoal.
  3038 In particular, rules that solve a subgoal outright are displayed first
  3039 (or rather last, the way they are printed).
  3040 (ML: ProofGeneral.print_intros())
  3041 
  3042 * Pure: New flag trace_unify_fail causes unification to print
  3043 diagnostic information (PG: in trace buffer) when it fails. This is
  3044 useful for figuring out why single step proofs like rule, erule or
  3045 assumption failed.
  3046 
  3047 * Pure: Locale specifications now produce predicate definitions
  3048 according to the body of text (covering assumptions modulo local
  3049 definitions); predicate "loc_axioms" covers newly introduced text,
  3050 while "loc" is cumulative wrt. all included locale expressions; the
  3051 latter view is presented only on export into the global theory
  3052 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3053 on the old view without predicates;
  3054 
  3055 * Pure: predefined locales "var" and "struct" are useful for sharing
  3056 parameters (as in CASL, for example); just specify something like
  3057 ``var x + var y + struct M'' as import;
  3058 
  3059 * Pure: improved thms_containing: proper indexing of facts instead of
  3060 raw theorems; check validity of results wrt. current name space;
  3061 include local facts of proof configuration (also covers active
  3062 locales), cover fixed variables in index; may use "_" in term
  3063 specification; an optional limit for the number of printed facts may
  3064 be given (the default is 40);
  3065 
  3066 * Pure: disallow duplicate fact bindings within new-style theory files
  3067 (batch-mode only);
  3068 
  3069 * Provers: improved induct method: assumptions introduced by case
  3070 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3071 the goal statement); "foo" still refers to all facts collectively;
  3072 
  3073 * Provers: the function blast.overloaded has been removed: all constants
  3074 are regarded as potentially overloaded, which improves robustness in exchange
  3075 for slight decrease in efficiency;
  3076 
  3077 * Provers/linorder: New generic prover for transitivity reasoning over
  3078 linear orders.  Note: this prover is not efficient!
  3079 
  3080 * Isar: preview of problems to finish 'show' now produce an error
  3081 rather than just a warning (in interactive mode);
  3082 
  3083 
  3084 *** HOL ***
  3085 
  3086 * arith(_tac)
  3087 
  3088  - Produces a counter example if it cannot prove a goal.
  3089    Note that the counter example may be spurious if the goal is not a formula
  3090    of quantifier-free linear arithmetic.
  3091    In ProofGeneral the counter example appears in the trace buffer.
  3092 
  3093  - Knows about div k and mod k where k is a numeral of type nat or int.
  3094 
  3095  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3096    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3097    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3098 
  3099 * simp's arithmetic capabilities have been enhanced a bit: it now
  3100 takes ~= in premises into account (by performing a case split);
  3101 
  3102 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3103 are distributed over a sum of terms;
  3104 
  3105 * New tactic "trans_tac" and method "trans" instantiate
  3106 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3107 "<=", "<" and "=").
  3108 
  3109 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3110 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3111 
  3112 * 'typedef' command has new option "open" to suppress the set
  3113 definition;
  3114 
  3115 * functions Min and Max on finite sets have been introduced (theory
  3116 Finite_Set);
  3117 
  3118 * attribute [symmetric] now works for relations as well; it turns
  3119 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3120 
  3121 * induct over a !!-quantified statement (say !!x1..xn):
  3122   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3123 
  3124 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3125 %x. None. Warning: empty_def now refers to the previously hidden definition
  3126 of the empty set.
  3127 
  3128 * Algebra: formalization of classical algebra.  Intended as base for
  3129 any algebraic development in Isabelle.  Currently covers group theory
  3130 (up to Sylow's theorem) and ring theory (Universal Property of
  3131 Univariate Polynomials).  Contributions welcome;
  3132 
  3133 * GroupTheory: deleted, since its material has been moved to Algebra;
  3134 
  3135 * Complex: new directory of the complex numbers with numeric constants,
  3136 nonstandard complex numbers, and some complex analysis, standard and
  3137 nonstandard (Jacques Fleuriot);
  3138 
  3139 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3140 
  3141 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3142 Fleuriot);
  3143 
  3144 * Real/HahnBanach: updated and adapted to locales;
  3145 
  3146 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3147 Gray and Kramer);
  3148 
  3149 * UNITY: added the Meier-Sanders theory of progress sets;
  3150 
  3151 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3152 as abstract algorithms, instantiated to the JVM;
  3153 
  3154 * Bali: Java source language formalization. Type system, operational
  3155 semantics, axiomatic semantics. Supported language features:
  3156 classes, interfaces, objects,virtual methods, static methods,
  3157 static/instance fields, arrays, access modifiers, definite
  3158 assignment, exceptions.
  3159 
  3160 
  3161 *** ZF ***
  3162 
  3163 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3164 universe, etc.);
  3165 
  3166 * Main ZF: virtually all theories converted to new-style format;
  3167 
  3168 
  3169 *** ML ***
  3170 
  3171 * Pure: Tactic.prove provides sane interface for internal proofs;
  3172 omits the infamous "standard" operation, so this is more appropriate
  3173 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3174 
  3175 * Pure: improved error reporting of simprocs;
  3176 
  3177 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3178 up simprocs;
  3179 
  3180 
  3181 *** Document preparation ***
  3182 
  3183 * uses \par instead of \\ for line breaks in theory text. This may
  3184 shift some page breaks in large documents. To get the old behaviour
  3185 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3186 
  3187 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3188 other packages
  3189 
  3190 * \<euro> now needs package babel/greek instead of marvosym (which
  3191 broke \Rightarrow)
  3192 
  3193 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3194 textcomp package)
  3195 
  3196 
  3197 
  3198 New in Isabelle2002 (March 2002)
  3199 --------------------------------
  3200 
  3201 *** Document preparation ***
  3202 
  3203 * greatly simplified document preparation setup, including more
  3204 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3205 instructive isatool mkdir; users should basically be able to get
  3206 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3207 users may run a separate document processing stage manually like this:
  3208 "isatool usedir -D output HOL Test && isatool document Test/output";
  3209 
  3210 * theory dependency graph may now be incorporated into documents;
  3211 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3212 with \includegraphics of LaTeX;
  3213 
  3214 * proper spacing of consecutive markup elements, especially text
  3215 blocks after section headings;
  3216 
  3217 * support bold style (for single symbols only), input syntax is like
  3218 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3219 
  3220 * \<bullet> is now output as bold \cdot by default, which looks much
  3221 better in printed text;
  3222 
  3223 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3224 note that these symbols are currently unavailable in Proof General /
  3225 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3226 
  3227 * isatool latex no longer depends on changed TEXINPUTS, instead
  3228 isatool document copies the Isabelle style files to the target
  3229 location;
  3230 
  3231 
  3232 *** Isar ***
  3233 
  3234 * Pure/Provers: improved proof by cases and induction;
  3235   - 'case' command admits impromptu naming of parameters (such as
  3236     "case (Suc n)");
  3237   - 'induct' method divinates rule instantiation from the inductive
  3238     claim; no longer requires excessive ?P bindings for proper
  3239     instantiation of cases;
  3240   - 'induct' method properly enumerates all possibilities of set/type
  3241     rules; as a consequence facts may be also passed through *type*
  3242     rules without further ado;
  3243   - 'induct' method now derives symbolic cases from the *rulified*
  3244     rule (before it used to rulify cases stemming from the internal
  3245     atomized version); this means that the context of a non-atomic
  3246     statement becomes is included in the hypothesis, avoiding the
  3247     slightly cumbersome show "PROP ?case" form;
  3248   - 'induct' may now use elim-style induction rules without chaining
  3249     facts, using ``missing'' premises from the goal state; this allows
  3250     rules stemming from inductive sets to be applied in unstructured
  3251     scripts, while still benefitting from proper handling of non-atomic
  3252     statements; NB: major inductive premises need to be put first, all
  3253     the rest of the goal is passed through the induction;
  3254   - 'induct' proper support for mutual induction involving non-atomic
  3255     rule statements (uses the new concept of simultaneous goals, see
  3256     below);
  3257   - append all possible rule selections, but only use the first
  3258     success (no backtracking);
  3259   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3260   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3261   - added 'print_induct_rules' (covered by help item in recent Proof
  3262     General versions);
  3263   - moved induct/cases attributes to Pure, methods to Provers;
  3264   - generic method setup instantiated for FOL and HOL;
  3265 
  3266 * Pure: support multiple simultaneous goal statements, for example
  3267 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3268 meta-level mechanism, this acts as if several individual goals had
  3269 been stated separately; in particular common proof methods need to be
  3270 repeated in order to cover all claims; note that a single elimination
  3271 step is *not* sufficient to establish the two conjunctions, so this
  3272 fails:
  3273 
  3274   assume "A & B" then have A and B ..   (*".." fails*)
  3275 
  3276 better use "obtain" in situations as above; alternative refer to
  3277 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3278 
  3279 * Pure: proper integration with ``locales''; unlike the original
  3280 version by Florian Kammller, Isar locales package high-level proof
  3281 contexts rather than raw logical ones (e.g. we admit to include
  3282 attributes everywhere); operations on locales include merge and
  3283 rename; support for implicit arguments (``structures''); simultaneous
  3284 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3285 some examples;
  3286 
  3287 * Pure: the following commands have been ``localized'', supporting a
  3288 target locale specification "(in name)": 'lemma', 'theorem',
  3289 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3290 stored both within the locale and at the theory level (exported and
  3291 qualified by the locale name);
  3292 
  3293 * Pure: theory goals may now be specified in ``long'' form, with
  3294 ad-hoc contexts consisting of arbitrary locale elements. for example
  3295 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3296 definitions may be given, too); the result is a meta-level rule with
  3297 the context elements being discharged in the obvious way;
  3298 
  3299 * Pure: new proof command 'using' allows to augment currently used
  3300 facts after a goal statement ('using' is syntactically analogous to
  3301 'apply', but acts on the goal's facts only); this allows chained facts
  3302 to be separated into parts given before and after a claim, as in
  3303 ``from a and b have C using d and e <proof>'';
  3304 
  3305 * Pure: renamed "antecedent" case to "rule_context";
  3306 
  3307 * Pure: new 'judgment' command records explicit information about the
  3308 object-logic embedding (used by several tools internally); no longer
  3309 use hard-wired "Trueprop";
  3310 
  3311 * Pure: added 'corollary' command;
  3312 
  3313 * Pure: fixed 'token_translation' command;
  3314 
  3315 * Pure: removed obsolete 'exported' attribute;
  3316 
  3317 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3318 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3319 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3320 
  3321 * Pure: method 'atomize' presents local goal premises as object-level
  3322 statements (atomic meta-level propositions); setup controlled via
  3323 rewrite rules declarations of 'atomize' attribute; example
  3324 application: 'induct' method with proper rule statements in improper
  3325 proof *scripts*;
  3326 
  3327 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3328 now consider the syntactic context of assumptions, giving a better
  3329 chance to get type-inference of the arguments right (this is
  3330 especially important for locales);
  3331 
  3332 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3333 mode;
  3334 
  3335 * Pure/obtain: the formal conclusion "thesis", being marked as
  3336 ``internal'', may no longer be reference directly in the text;
  3337 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3338 situations;
  3339 
  3340 * Pure: generic 'sym' attribute which declares a rule both as pure
  3341 'elim?' and for the 'symmetric' operation;
  3342 
  3343 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3344 text; the fixed correlation with particular command syntax has been
  3345 discontinued;
  3346 
  3347 * Pure: new method 'rules' is particularly well-suited for proof
  3348 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3349 but often produces more compact proof terms with less detours;
  3350 
  3351 * Pure/Provers/classical: simplified integration with pure rule
  3352 attributes and methods; the classical "intro?/elim?/dest?"
  3353 declarations coincide with the pure ones; the "rule" method no longer
  3354 includes classically swapped intros; "intro" and "elim" methods no
  3355 longer pick rules from the context; also got rid of ML declarations
  3356 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3357 INCOMPATIBILITY;
  3358 
  3359 * Provers/classical: attribute 'swapped' produces classical inversions
  3360 of introduction rules;
  3361 
  3362 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3363 rules instead of full simplifier context; 'iff' attribute handles
  3364 conditional rules;
  3365 
  3366 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3367 
  3368 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3369 "(permissive)" option to recover old behavior;
  3370 
  3371 * HOL: 'inductive' no longer features separate (collective) attributes
  3372 for 'intros' (was found too confusing);
  3373 
  3374 * HOL: properly declared induction rules less_induct and
  3375 wf_induct_rule;
  3376 
  3377 
  3378 *** HOL ***
  3379 
  3380 * HOL: moved over to sane numeral syntax; the new policy is as
  3381 follows:
  3382 
  3383   - 0 and 1 are polymorphic constants, which are defined on any
  3384   numeric type (nat, int, real etc.);
  3385 
  3386   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3387   binary representation internally;
  3388 
  3389   - type nat has special constructor Suc, and generally prefers Suc 0
  3390   over 1::nat and Suc (Suc 0) over 2::nat;
  3391 
  3392 This change may cause significant problems of INCOMPATIBILITY; here
  3393 are some hints on converting existing sources:
  3394 
  3395   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3396   entities, so expressions involving "-" (unary or binary minus) need
  3397   to be spaced properly;
  3398 
  3399   - existing occurrences of "1" may need to be constraint "1::nat" or
  3400   even replaced by Suc 0; similar for old "2";
  3401 
  3402   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3403 
  3404   - remove all special provisions on numerals in proofs;
  3405 
  3406 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3407 representation (depends on bin_arith_simps in the default context);
  3408 
  3409 * HOL: symbolic syntax for x^2 (numeral 2);
  3410 
  3411 * HOL: the class of all HOL types is now called "type" rather than
  3412 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3413 in axclass/classes, instance/arities, and (usually rare) occurrences
  3414 in typings (of consts etc.); internally the class is called
  3415 "HOL.type", ML programs should refer to HOLogic.typeS;
  3416 
  3417 * HOL/record package improvements:
  3418   - new derived operations "fields" to build a partial record section,
  3419     "extend" to promote a fixed record to a record scheme, and
  3420     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3421     declared as simp by default;
  3422   - shared operations ("more", "fields", etc.) now need to be always
  3423     qualified) --- potential INCOMPATIBILITY;
  3424   - removed "make_scheme" operations (use "make" with "extend") --
  3425     INCOMPATIBILITY;
  3426   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3427   - provides cases/induct rules for use with corresponding Isar
  3428     methods (for concrete records, record schemes, concrete more
  3429     parts, and schematic more parts -- in that order);
  3430   - internal definitions directly based on a light-weight abstract
  3431     theory of product types over typedef rather than datatype;
  3432 
  3433 * HOL: generic code generator for generating executable ML code from
  3434 specifications; specific support for HOL constructs such as inductive
  3435 datatypes and sets, as well as recursive functions; can be invoked
  3436 via 'generate_code' theory section;
  3437 
  3438 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3439 
  3440 * HOL: consolidated and renamed several theories.  In particular:
  3441         Ord.thy has been absorbed into HOL.thy
  3442         String.thy has been absorbed into List.thy
  3443 
  3444 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3445 (beware of argument permutation!);
  3446 
  3447 * HOL: linorder_less_split superseded by linorder_cases;
  3448 
  3449 * HOL/List: "nodups" renamed to "distinct";
  3450 
  3451 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3452 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3453   - Ex_def has changed, now need to use some_eq_ex
  3454 
  3455 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3456 in this (rare) case use:
  3457 
  3458   delSWrapper "split_all_tac"
  3459   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3460 
  3461 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3462 MAY FAIL;
  3463 
  3464 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3465 Isabelle's type classes, ^ on functions and relations has too general
  3466 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3467 necessary to attach explicit type constraints;
  3468 
  3469 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3470 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3471 renamed accordingly (eg "compI" -> "rel_compI").
  3472 
  3473 * HOL: syntax translations now work properly with numerals and records
  3474 expressions;
  3475 
  3476 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3477 of "lam" -- INCOMPATIBILITY;
  3478 
  3479 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3480 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3481 renamed "Product_Type.unit";
  3482 
  3483 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3484 
  3485 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3486 the "cases" method);
  3487 
  3488 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3489 Florian Kammller);
  3490 
  3491 * HOL/IMP: updated and converted to new-style theory format; several
  3492 parts turned into readable document, with proper Isar proof texts and
  3493 some explanations (by Gerwin Klein);
  3494 
  3495 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3496 
  3497 * HOL-Hyperreal is now a logic image;
  3498 
  3499 
  3500 *** HOLCF ***
  3501 
  3502 * Isar: consts/constdefs supports mixfix syntax for continuous
  3503 operations;
  3504 
  3505 * Isar: domain package adapted to new-style theory format, e.g. see
  3506 HOLCF/ex/Dnat.thy;
  3507 
  3508 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3509 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3510 lift.induct_tac, always use UU instead of Undef;
  3511 
  3512 * HOLCF/IMP: updated and converted to new-style theory;
  3513 
  3514 
  3515 *** ZF ***
  3516 
  3517 * Isar: proper integration of logic-specific tools and packages,
  3518 including theory commands '(co)inductive', '(co)datatype',
  3519 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3520 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3521 
  3522 * theory Main no longer includes AC; for the Axiom of Choice, base
  3523 your theory on Main_ZFC;
  3524 
  3525 * the integer library now covers quotients and remainders, with many
  3526 laws relating division to addition, multiplication, etc.;
  3527 
  3528 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3529 typeless version of the formalism;
  3530 
  3531 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3532 format;
  3533 
  3534 * ZF/Induct: new directory for examples of inductive definitions,
  3535 including theory Multiset for multiset orderings; converted to
  3536 new-style theory format;
  3537 
  3538 * ZF: many new theorems about lists, ordinals, etc.;
  3539 
  3540 
  3541 *** General ***
  3542 
  3543 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3544 variable proof controls level of detail: 0 = no proofs (only oracle
  3545 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3546 also ref manual for further ML interfaces;
  3547 
  3548 * Pure/axclass: removed obsolete ML interface
  3549 goal_subclass/goal_arity;
  3550 
  3551 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3552 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3553 separate tokens, so expressions involving minus need to be spaced
  3554 properly;
  3555 
  3556 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3557 rather than "infixl" or "infixr";
  3558 
  3559 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3560 sort constraint specifications in type inference; e.g. "x::_::foo"
  3561 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3562 type variable);
  3563 
  3564 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3565 control output of nested => (types); the default behavior is
  3566 "type_brackets";
  3567 
  3568 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3569 tokens into AST constants;
  3570 
  3571 * Pure/syntax: prefer later declarations of translations and print
  3572 translation functions; potential INCOMPATIBILITY: need to reverse
  3573 multiple declarations for same syntax element constant;
  3574 
  3575 * Pure/show_hyps reset by default (in accordance to existing Isar
  3576 practice);
  3577 
  3578 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3579 addSafter;
  3580 
  3581 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3582 as well;
  3583 
  3584 * system: tested support for MacOS X; should be able to get Isabelle +
  3585 Proof General to work in a plain Terminal after installing Poly/ML
  3586 (e.g. from the Isabelle distribution area) and GNU bash alone
  3587 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3588 support requires further installations, e.g. from
  3589 http://fink.sourceforge.net/);
  3590 
  3591 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3592 
  3593 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3594 of 40 MB), cf. ML_OPTIONS;
  3595 
  3596 * system: Proof General keywords specification is now part of the
  3597 Isabelle distribution (see etc/isar-keywords.el);
  3598 
  3599 * system: support for persistent Proof General sessions (refrain from
  3600 outdating all loaded theories on startup); user may create writable
  3601 logic images like this: ``isabelle -q HOL Test'';
  3602 
  3603 * system: smart selection of Isabelle process versus Isabelle
  3604 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3605 run both "isabelle" and "Isabelle" even if file names are badly
  3606 damaged (executable inspects the case of the first letter of its own
  3607 name); added separate "isabelle-process" and "isabelle-interface";
  3608 
  3609 * system: refrain from any attempt at filtering input streams; no
  3610 longer support ``8bit'' encoding of old isabelle font, instead proper
  3611 iso-latin characters may now be used; the related isatools
  3612 "symbolinput" and "nonascii" have disappeared as well;
  3613 
  3614 * system: removed old "xterm" interface (the print modes "xterm" and
  3615 "xterm_color" are still available for direct use in a suitable
  3616 terminal);
  3617 
  3618 
  3619 
  3620 New in Isabelle99-2 (February 2001)
  3621 -----------------------------------
  3622 
  3623 *** Overview of INCOMPATIBILITIES ***
  3624 
  3625 * HOL: please note that theories in the Library and elsewhere often use the
  3626 new-style (Isar) format; to refer to their theorems in an ML script you must
  3627 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3628 
  3629 * HOL: inductive package no longer splits induction rule aggressively,
  3630 but only as far as specified by the introductions given; the old
  3631 format may be recovered via ML function complete_split_rule or attribute
  3632 'split_rule (complete)';
  3633 
  3634 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3635 gfp_Tarski to gfp_unfold;
  3636 
  3637 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3638 
  3639 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3640 relation); infix "^^" has been renamed "``"; infix "``" has been
  3641 renamed "`"; "univalent" has been renamed "single_valued";
  3642 
  3643 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3644 operation;
  3645 
  3646 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3647 
  3648 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3649 
  3650 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3651 consequence, it is no longer monotonic wrt. the local goal context
  3652 (which is now passed through the inductive cases);
  3653 
  3654 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3655 \<gg> to \<ggreater>;
  3656 
  3657 
  3658 *** Document preparation ***
  3659 
  3660 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3661 available: are "it" for near math-mode best-style output, "sl" for
  3662 slanted text style, and "tt" for plain type-writer; if no
  3663 \isabellestyle command is given, output is according to slanted
  3664 type-writer);
  3665 
  3666 * support sub/super scripts (for single symbols only), input syntax is
  3667 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3668 
  3669 * some more standard symbols; see Appendix A of the system manual for
  3670 the complete list of symbols defined in isabellesym.sty;
  3671 
  3672 * improved isabelle style files; more abstract symbol implementation
  3673 (should now use \isamath{...} and \isatext{...} in custom symbol
  3674 definitions);
  3675 
  3676 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3677 state; Note that presentation of goal states does not conform to
  3678 actual human-readable proof documents.  Please do not include goal
  3679 states into document output unless you really know what you are doing!
  3680 
  3681 * proper indentation of antiquoted output with proportional LaTeX
  3682 fonts;
  3683 
  3684 * no_document ML operator temporarily disables LaTeX document
  3685 generation;
  3686 
  3687 * isatool unsymbolize tunes sources for plain ASCII communication;
  3688 
  3689 
  3690 *** Isar ***
  3691 
  3692 * Pure: Isar now suffers initial goal statements to contain unbound
  3693 schematic variables (this does not conform to actual readable proof
  3694 documents, due to unpredictable outcome and non-compositional proof
  3695 checking); users who know what they are doing may use schematic goals
  3696 for Prolog-style synthesis of proven results;
  3697 
  3698 * Pure: assumption method (an implicit finishing) now handles actual
  3699 rules as well;
  3700 
  3701 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3702 initial goal, declare "that" only as Pure intro (only for single
  3703 steps); the "that" rule assumption may now be involved in implicit
  3704 finishing, thus ".." becomes a feasible for trivial obtains;
  3705 
  3706 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3707 instance proofs may be performed by "..";
  3708 
  3709 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3710 statements as well;
  3711 
  3712 * Pure: more robust selection of calculational rules;
  3713 
  3714 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3715 rule (as well as the assumption rule);
  3716 
  3717 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3718 lemmas, using the graph browser tool;
  3719 
  3720 * Pure: predict failure of "show" in interactive mode;
  3721 
  3722 * Pure: 'thms_containing' now takes actual terms as arguments;
  3723 
  3724 * HOL: improved method 'induct' --- now handles non-atomic goals
  3725 (potential INCOMPATIBILITY); tuned error handling;
  3726 
  3727 * HOL: cases and induct rules now provide explicit hints about the
  3728 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3729 any remaining facts are inserted into the goal verbatim;
  3730 
  3731 * HOL: local contexts (aka cases) may now contain term bindings as
  3732 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3733 the result to be shown in each case;
  3734 
  3735 * HOL: added 'recdef_tc' command;
  3736 
  3737 * isatool convert assists in eliminating legacy ML scripts;
  3738 
  3739 
  3740 *** HOL ***
  3741 
  3742 * HOL/Library: a collection of generic theories to be used together
  3743 with main HOL; the theory loader path already includes this directory
  3744 by default; the following existing theories have been moved here:
  3745 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3746 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3747 
  3748 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3749 modelling and verification task performed in Isabelle/HOL +
  3750 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3751 
  3752 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3753 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3754 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3755 'domain', this makes the theory consistent with mathematical
  3756 literature;
  3757 
  3758 * HOL basics: added overloaded operations "inverse" and "divide"
  3759 (infix "/"), syntax for generic "abs" operation, generic summation
  3760 operator \<Sum>;
  3761 
  3762 * HOL/typedef: simplified package, provide more useful rules (see also
  3763 HOL/subset.thy);
  3764 
  3765 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3766 now expressed as a proper nested rule (old-style tactic scripts may
  3767 require atomize_strip_tac to cope with non-atomic premises);
  3768 
  3769 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3770 to "split_conv" (old name still available for compatibility);
  3771 
  3772 * HOL: improved concrete syntax for strings (e.g. allows translation
  3773 rules with string literals);
  3774 
  3775 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3776  and Fleuriot's mechanization of analysis, including the transcendental
  3777  functions for the reals;
  3778 
  3779 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3780 
  3781 
  3782 *** CTT ***
  3783 
  3784 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3785 "lam" is displayed as TWO lambda-symbols
  3786 
  3787 * CTT: theory Main now available, containing everything (that is, Bool
  3788 and Arith);
  3789 
  3790 
  3791 *** General ***
  3792 
  3793 * Pure: the Simplifier has been implemented properly as a derived rule
  3794 outside of the actual kernel (at last!); the overall performance
  3795 penalty in practical applications is about 50%, while reliability of
  3796 the Isabelle inference kernel has been greatly improved;
  3797 
  3798 * print modes "brackets" and "no_brackets" control output of nested =>
  3799 (types) and ==> (props); the default behaviour is "brackets";
  3800 
  3801 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3802 as assumptions as well;
  3803 
  3804 * system: support Poly/ML 4.0;
  3805 
  3806 * system: isatool install handles KDE version 1 or 2;
  3807 
  3808 
  3809 
  3810 New in Isabelle99-1 (October 2000)
  3811 ----------------------------------
  3812 
  3813 *** Overview of INCOMPATIBILITIES ***
  3814 
  3815 * HOL: simplification of natural numbers is much changed; to partly
  3816 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3817 issue the following ML commands:
  3818 
  3819   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3820   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3821 
  3822 * HOL: simplification no longer dives into case-expressions; this is
  3823 controlled by "t.weak_case_cong" for each datatype t;
  3824 
  3825 * HOL: nat_less_induct renamed to less_induct;
  3826 
  3827 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3828 fixsome to patch .thy and .ML sources automatically;
  3829 
  3830   select_equality  -> some_equality
  3831   select_eq_Ex     -> some_eq_ex
  3832   selectI2EX       -> someI2_ex
  3833   selectI2         -> someI2
  3834   selectI          -> someI
  3835   select1_equality -> some1_equality
  3836   Eps_sym_eq       -> some_sym_eq_trivial
  3837   Eps_eq           -> some_eq_trivial
  3838 
  3839 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3840 
  3841 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3842 instead);
  3843 
  3844 * HOL: the recursion equations generated by 'recdef' are now called
  3845 f.simps instead of f.rules;
  3846 
  3847 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3848 
  3849 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3850 sometimes be needed;
  3851 
  3852 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3853 
  3854 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3855 
  3856 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3857 product is now "<*>" instead of "Times"; the lexicographic product is
  3858 now "<*lex*>" instead of "**";
  3859 
  3860 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3861 of main HOL, but was unused); better use HOL's datatype package;
  3862 
  3863 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3864 the old syntax may be recovered as follows:
  3865 
  3866   syntax (symbols)
  3867     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3868       (infixl "\\<oplus>" 100)
  3869 
  3870 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3871 
  3872 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3873 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3874 internally;
  3875 
  3876 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3877 changed from A/r to A//r;
  3878 
  3879 * ZF: new treatment of arithmetic (nat & int) may break some old
  3880 proofs;
  3881 
  3882 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3883 rulify -> rule_format, elimify -> elim_format, ...);
  3884 
  3885 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3886 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3887 should have to change intro!! to intro? only); replaced "delrule" by
  3888 "rule del";
  3889 
  3890 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3891 
  3892 * Provers: strengthened force_tac by using new first_best_tac;
  3893 
  3894 * LaTeX document preparation: several changes of isabelle.sty (see
  3895 lib/texinputs);
  3896 
  3897 
  3898 *** Document preparation ***
  3899 
  3900 * formal comments (text blocks etc.) in new-style theories may now
  3901 contain antiquotations of thm/prop/term/typ/text to be presented
  3902 according to latex print mode; concrete syntax is like this:
  3903 @{term[show_types] "f(x) = a + x"};
  3904 
  3905 * isatool mkdir provides easy setup of Isabelle session directories,
  3906 including proper document sources;
  3907 
  3908 * generated LaTeX sources are now deleted after successful run
  3909 (isatool document -c); may retain a copy somewhere else via -D option
  3910 of isatool usedir;
  3911 
  3912 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3913 style files, achieving self-contained LaTeX sources and simplifying
  3914 LaTeX debugging;
  3915 
  3916 * old-style theories now produce (crude) LaTeX output as well;
  3917 
  3918 * browser info session directories are now self-contained (may be put
  3919 on WWW server seperately); improved graphs of nested sessions; removed
  3920 graph for 'all sessions';
  3921 
  3922 * several improvements in isabelle style files; \isabellestyle{it}
  3923 produces fake math mode output; \isamarkupheader is now \section by
  3924 default; see lib/texinputs/isabelle.sty etc.;
  3925 
  3926 
  3927 *** Isar ***
  3928 
  3929 * Isar/Pure: local results and corresponding term bindings are now
  3930 subject to Hindley-Milner polymorphism (similar to ML); this
  3931 accommodates incremental type-inference very nicely;
  3932 
  3933 * Isar/Pure: new derived language element 'obtain' supports
  3934 generalized existence reasoning;
  3935 
  3936 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3937 support accumulation of results, without applying any rules yet;
  3938 useful to collect intermediate results without explicit name
  3939 references, and for use with transitivity rules with more than 2
  3940 premises;
  3941 
  3942 * Isar/Pure: scalable support for case-analysis type proofs: new
  3943 'case' language element refers to local contexts symbolically, as
  3944 produced by certain proof methods; internally, case names are attached
  3945 to theorems as "tags";
  3946 
  3947 * Isar/Pure: theory command 'hide' removes declarations from
  3948 class/type/const name spaces;
  3949 
  3950 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3951 indicate potential overloading;
  3952 
  3953 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3954 
  3955 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3956 "{a,b,c}" instead of {a,b,c};
  3957 
  3958 * Isar/Pure now provides its own version of intro/elim/dest
  3959 attributes; useful for building new logics, but beware of confusion
  3960 with the version in Provers/classical;
  3961 
  3962 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3963 case name 'antecedent';
  3964 
  3965 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3966 to the current context is now done automatically);
  3967 
  3968 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3969 for definining proof methods in ML;
  3970 
  3971 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3972 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3973 most cases, one should have to change intro!! to intro? only);
  3974 replaced "delrule" by "rule del";
  3975 
  3976 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3977 'symmetric' attribute (the latter supercedes [RS sym]);
  3978 
  3979 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3980 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3981 well (including splits);
  3982 
  3983 * Isar/Provers: Simplifier and Classical methods now support all kind
  3984 of modifiers used in the past, including 'cong', 'iff', etc.
  3985 
  3986 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3987 of Simplifier and Classical reasoner);
  3988 
  3989 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3990 now support named cases; major packages (inductive, datatype, primrec,
  3991 recdef) support case names and properly name parameters;
  3992 
  3993 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3994 monotonicity conditions are extracted to be proven at end of
  3995 calculations;
  3996 
  3997 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3998 method anyway;
  3999 
  4000 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4001 split_if split_if_asm; datatype package provides theorems foo.splits =
  4002 foo.split foo.split_asm for each datatype;
  4003 
  4004 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4005 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4006 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4007 use "(cases (simplified))" method in proper proof texts);
  4008 
  4009 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4010 
  4011 * Isar: names of theorems etc. may be natural numbers as well;
  4012 
  4013 * Isar: 'pr' command: optional arguments for goals_limit and
  4014 ProofContext.prems_limit; no longer prints theory contexts, but only
  4015 proof states;
  4016 
  4017 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4018 additional print modes to be specified; e.g. "pr(latex)" will print
  4019 proof state according to the Isabelle LaTeX style;
  4020 
  4021 * Isar: improved support for emulating tactic scripts, including proof
  4022 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4023 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4024 (for HOL datatypes);
  4025 
  4026 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4027 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4028 'proof method scripts' have to be in depth-first order;
  4029 
  4030 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4031 
  4032 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4033 should instead use individual commands for printing items
  4034 (print_commands, print_methods etc.);
  4035 
  4036 * Isar: added 'nothing' --- the empty list of theorems;
  4037 
  4038 
  4039 *** HOL ***
  4040 
  4041 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4042 corresponding virtual machine and a specification of its bytecode
  4043 verifier and a lightweight bytecode verifier, including proofs of
  4044 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4045 Cornelia Pusch (see also the homepage of project Bali at
  4046 http://isabelle.in.tum.de/Bali/);
  4047 
  4048 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4049 Clemens Ballarin;
  4050 
  4051 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4052 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4053 Rasmussen;
  4054 
  4055 * HOL/Lattice: fundamental concepts of lattice theory and order
  4056 structures, including duals, properties of bounds versus algebraic
  4057 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4058 Theorem for complete lattices etc.; may also serve as a demonstration
  4059 for abstract algebraic reasoning using axiomatic type classes, and
  4060 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4061 
  4062 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4063 von Oheimb;
  4064 
  4065 * HOL/IMPP: extension of IMP with local variables and mutually
  4066 recursive procedures, by David von Oheimb;
  4067 
  4068 * HOL/Lambda: converted into new-style theory and document;
  4069 
  4070 * HOL/ex/Multiquote: example of multiple nested quotations and
  4071 anti-quotations -- basically a generalized version of de-Bruijn
  4072 representation; very useful in avoiding lifting of operations;
  4073 
  4074 * HOL/record: added general record equality rule to simpset; fixed
  4075 select-update simplification procedure to handle extended records as
  4076 well; admit "r" as field name;
  4077 
  4078 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4079 other numeric types and also as the identity of groups, rings, etc.;
  4080 
  4081 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4082 Types nat and int belong to this axclass;
  4083 
  4084 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4085    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4086    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4087   two terms #m*u and #n*u are replaced by #(m+n)*u
  4088     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4089   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4090     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4091 
  4092 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4093 powerful prover for predicate logic but knows nothing of clasets; see
  4094 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4095 
  4096 * HOL: new version of "case_tac" subsumes both boolean case split and
  4097 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4098 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4099 
  4100 * HOL: simplification no longer dives into case-expressions: only the
  4101 selector expression is simplified, but not the remaining arms; to
  4102 enable full simplification of case-expressions for datatype t, you may
  4103 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4104 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4105 
  4106 * HOL/recdef: the recursion equations generated by 'recdef' for
  4107 function 'f' are now called f.simps instead of f.rules; if all
  4108 termination conditions are proved automatically, these simplification
  4109 rules are added to the simpset, as in primrec; rules may be named
  4110 individually as well, resulting in a separate list of theorems for
  4111 each equation;
  4112 
  4113 * HOL/While is a new theory that provides a while-combinator. It
  4114 permits the definition of tail-recursive functions without the
  4115 provision of a termination measure. The latter is necessary once the
  4116 invariant proof rule for while is applied.
  4117 
  4118 * HOL: new (overloaded) notation for the set of elements below/above
  4119 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4120 
  4121 * HOL: theorems impI, allI, ballI bound as "strip";
  4122 
  4123 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4124 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4125 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4126 
  4127 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4128 
  4129 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4130 main HOL, but was unused);
  4131 
  4132 * HOL: fewer consts declared as global (e.g. have to refer to
  4133 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4134 
  4135 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4136 in case of overlap with user translations (e.g. judgements over
  4137 tuples); (note that the underlying logical represenation is still
  4138 bogus);
  4139 
  4140 
  4141 *** ZF ***
  4142 
  4143 * ZF: simplification automatically cancels common terms in arithmetic
  4144 expressions over nat and int;
  4145 
  4146 * ZF: new treatment of nat to minimize type-checking: all operators
  4147 coerce their operands to a natural number using the function natify,
  4148 making the algebraic laws unconditional;
  4149 
  4150 * ZF: as above, for int: operators coerce their operands to an integer
  4151 using the function intify;
  4152 
  4153 * ZF: the integer library now contains many of the usual laws for the
  4154 orderings, including $<=, and monotonicity laws for $+ and $*;
  4155 
  4156 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4157 simplification;
  4158 
  4159 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4160 to the simplifier and classical reasoner simultaneously;
  4161 
  4162 
  4163 *** General ***
  4164 
  4165 * Provers: blast_tac now handles actual object-logic rules as
  4166 assumptions; note that auto_tac uses blast_tac internally as well;
  4167 
  4168 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4169 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4170 
  4171 * Provers: delrules now handles destruct rules as well (no longer need
  4172 explicit make_elim);
  4173 
  4174 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4175   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4176 use instead the strong form,
  4177   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4178 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4179 from destruct-rules;
  4180 
  4181 * Provers: Simplifier.easy_setup provides a fast path to basic
  4182 Simplifier setup for new object-logics;
  4183 
  4184 * Pure: AST translation rules no longer require constant head on LHS;
  4185 
  4186 * Pure: improved name spaces: ambiguous output is qualified; support
  4187 for hiding of names;
  4188 
  4189 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4190 XSYMBOL_HOME; no longer need to do manual configuration in most
  4191 situations;
  4192 
  4193 * system: compression of ML heaps images may now be controlled via -c
  4194 option of isabelle and isatool usedir (currently only observed by
  4195 Poly/ML);
  4196 
  4197 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4198 useful for remote X11);
  4199 
  4200 * system: provide TAGS file for Isabelle sources;
  4201 
  4202 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4203 order;
  4204 
  4205 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4206 timing flag supersedes proof_timing and Toplevel.trace;
  4207 
  4208 * ML: new combinators |>> and |>>> for incremental transformations
  4209 with secondary results (e.g. certain theory extensions):
  4210 
  4211 * ML: PureThy.add_defs gets additional argument to indicate potential
  4212 overloading (usually false);
  4213 
  4214 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4215 results;
  4216 
  4217 
  4218 
  4219 New in Isabelle99 (October 1999)
  4220 --------------------------------
  4221 
  4222 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4223 
  4224 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4225 are no longer simplified.  (This allows the simplifier to unfold recursive
  4226 functional programs.)  To restore the old behaviour, declare
  4227 
  4228     Delcongs [if_weak_cong];
  4229 
  4230 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4231 complement;
  4232 
  4233 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4234 
  4235 * HOL/datatype: mutual_induct_tac no longer exists --
  4236   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4237 
  4238 * HOL/typedef: fixed type inference for representing set; type
  4239 arguments now have to occur explicitly on the rhs as type constraints;
  4240 
  4241 * ZF: The con_defs part of an inductive definition may no longer refer
  4242 to constants declared in the same theory;
  4243 
  4244 * HOL, ZF: the function mk_cases, generated by the inductive
  4245 definition package, has lost an argument.  To simplify its result, it
  4246 uses the default simpset instead of a supplied list of theorems.
  4247 
  4248 * HOL/List: the constructors of type list are now Nil and Cons;
  4249 
  4250 * Simplifier: the type of the infix ML functions
  4251         setSSolver addSSolver setSolver addSolver
  4252 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4253 for packaging solvers. A solver is created via
  4254         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4255 where the string argument is only a comment.
  4256 
  4257 
  4258 *** Proof tools ***
  4259 
  4260 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4261 decision procedure for linear arithmetic. Currently it is used for
  4262 types `nat', `int', and `real' in HOL (see below); it can, should and
  4263 will be instantiated for other types and logics as well.
  4264 
  4265 * The simplifier now accepts rewrite rules with flexible heads, eg
  4266      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4267   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4268   matching.
  4269 
  4270 
  4271 *** General ***
  4272 
  4273 * New Isabelle/Isar subsystem provides an alternative to traditional
  4274 tactical theorem proving; together with the ProofGeneral/isar user
  4275 interface it offers an interactive environment for developing human
  4276 readable proof documents (Isar == Intelligible semi-automated
  4277 reasoning); for further information see isatool doc isar-ref,
  4278 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4279 
  4280 * improved and simplified presentation of theories: better HTML markup
  4281 (including colors), graph views in several sizes; isatool usedir now
  4282 provides a proper interface for user theories (via -P option); actual
  4283 document preparation based on (PDF)LaTeX is available as well (for
  4284 new-style theories only); see isatool doc system for more information;
  4285 
  4286 * native support for Proof General, both for classic Isabelle and
  4287 Isabelle/Isar;
  4288 
  4289 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4290 using the graph browser tool;
  4291 
  4292 * Isabelle manuals now also available as PDF;
  4293 
  4294 * theory loader rewritten from scratch (may not be fully
  4295 bug-compatible); old loadpath variable has been replaced by show_path,
  4296 add_path, del_path, reset_path functions; new operations such as
  4297 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4298 isatool doc ref);
  4299 
  4300 * improved isatool install: option -k creates KDE application icon,
  4301 option -p DIR installs standalone binaries;
  4302 
  4303 * added ML_PLATFORM setting (useful for cross-platform installations);
  4304 more robust handling of platform specific ML images for SML/NJ;
  4305 
  4306 * the settings environment is now statically scoped, i.e. it is never
  4307 created again in sub-processes invoked from isabelle, isatool, or
  4308 Isabelle;
  4309 
  4310 * path element specification '~~' refers to '$ISABELLE_HOME';
  4311 
  4312 * in locales, the "assumes" and "defines" parts may be omitted if
  4313 empty;
  4314 
  4315 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4316 long arrows);
  4317 
  4318 * new print_mode "HTML";
  4319 
  4320 * new flag show_tags controls display of tags of theorems (which are
  4321 basically just comments that may be attached by some tools);
  4322 
  4323 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4324 mode and goal output format:
  4325 
  4326 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4327 244c244
  4328 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4329 ---
  4330 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4331 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4332 181c181
  4333 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4334 ---
  4335 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4336 
  4337 * function bind_thms stores lists of theorems (cf. bind_thm);
  4338 
  4339 * new shorthand tactics ftac, eatac, datac, fatac;
  4340 
  4341 * qed (and friends) now accept "" as result name; in that case the
  4342 theorem is not stored, but proper checks and presentation of the
  4343 result still apply;
  4344 
  4345 * theorem database now also indexes constants "Trueprop", "all",
  4346 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4347 
  4348 
  4349 *** HOL ***
  4350 
  4351 ** HOL arithmetic **
  4352 
  4353 * There are now decision procedures for linear arithmetic over nat and
  4354 int:
  4355 
  4356 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4357 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4358 are treated as atomic; subformulae not involving type `nat' or `int'
  4359 are ignored; quantified subformulae are ignored unless they are
  4360 positive universal or negative existential. The tactic has to be
  4361 invoked by hand and can be a little bit slow. In particular, the
  4362 running time is exponential in the number of occurrences of `min' and
  4363 `max', and `-' on `nat'.
  4364 
  4365 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4366 (negated) (in)equalities among the premises and the conclusion into
  4367 account (i.e. no compound formulae) and does not know about `min' and
  4368 `max', and `-' on `nat'. It is fast and is used automatically by the
  4369 simplifier.
  4370 
  4371 NB: At the moment, these decision procedures do not cope with mixed
  4372 nat/int formulae where the two parts interact, such as `m < n ==>
  4373 int(m) < int(n)'.
  4374 
  4375 * HOL/Numeral provides a generic theory of numerals (encoded
  4376 efficiently as bit strings); setup for types nat/int/real is in place;
  4377 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4378 int, existing theories and proof scripts may require a few additional
  4379 type constraints;
  4380 
  4381 * integer division and remainder can now be performed on constant
  4382 arguments;
  4383 
  4384 * many properties of integer multiplication, division and remainder
  4385 are now available;
  4386 
  4387 * An interface to the Stanford Validity Checker (SVC) is available through the
  4388 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4389 are proved automatically.  SVC must be installed separately, and its results
  4390 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4391 invocation of the underlying oracle).  For SVC see
  4392   http://verify.stanford.edu/SVC
  4393 
  4394 * IsaMakefile: the HOL-Real target now builds an actual image;
  4395 
  4396 
  4397 ** HOL misc **
  4398 
  4399 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4400 (in Isabelle/Isar) -- by Gertrud Bauer;
  4401 
  4402 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4403 analysis for assembly languages with subtypes;
  4404 
  4405 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4406 -- avoids syntactic ambiguities and treats state, transition, and
  4407 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4408 changed syntax and (many) tactics;
  4409 
  4410 * HOL/inductive: Now also handles more general introduction rules such
  4411   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4412   theorems are now maintained within the theory (maintained via the
  4413   "mono" attribute);
  4414 
  4415 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4416   (using function types) such as
  4417 
  4418   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4419 
  4420 * HOL/record: record_simproc (part of the default simpset) takes care
  4421 of selectors applied to updated records; record_split_tac is no longer
  4422 part of the default claset; update_defs may now be removed from the
  4423 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4424 
  4425   claset_ref () := claset() addSWrapper record_split_wrapper;
  4426   Delsimprocs [record_simproc]
  4427 
  4428 * HOL/typedef: fixed type inference for representing set; type
  4429 arguments now have to occur explicitly on the rhs as type constraints;
  4430 
  4431 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4432 names rather than an ML expression;
  4433 
  4434 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4435 supplied later.  Program schemes can be defined, such as
  4436     "While B C s = (if B s then While B C (C s) else s)"
  4437 where the well-founded relation can be chosen after B and C have been given.
  4438 
  4439 * HOL/List: the constructors of type list are now Nil and Cons;
  4440 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4441 course, ML tools referring to List.list.op # etc. have to be adapted;
  4442 
  4443 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4444 disabled by default; run isabelle with option -m HOL to get back to
  4445 the original Gordon/HOL-style output;
  4446 
  4447 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4448 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4449 
  4450 * HOL basic syntax simplified (more orthogonal): all variants of
  4451 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4452 Eps operator is provided as well: "SOME x. P[x]";
  4453 
  4454 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4455 
  4456 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4457 thus available for user theories;
  4458 
  4459 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4460 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4461 time;
  4462 
  4463 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4464 several times and then mp;
  4465 
  4466 
  4467 *** LK ***
  4468 
  4469 * the notation <<...>> is now available as a notation for sequences of
  4470 formulas;
  4471 
  4472 * the simplifier is now installed
  4473 
  4474 * the axiom system has been generalized (thanks to Soren Heilmann)
  4475 
  4476 * the classical reasoner now has a default rule database
  4477 
  4478 
  4479 *** ZF ***
  4480 
  4481 * new primrec section allows primitive recursive functions to be given
  4482 directly (as in HOL) over datatypes and the natural numbers;
  4483 
  4484 * new tactics induct_tac and exhaust_tac for induction (or case
  4485 analysis) over datatypes and the natural numbers;
  4486 
  4487 * the datatype declaration of type T now defines the recursor T_rec;
  4488 
  4489 * simplification automatically does freeness reasoning for datatype
  4490 constructors;
  4491 
  4492 * automatic type-inference, with AddTCs command to insert new
  4493 type-checking rules;
  4494 
  4495 * datatype introduction rules are now added as Safe Introduction rules
  4496 to the claset;
  4497 
  4498 * the syntax "if P then x else y" is now available in addition to
  4499 if(P,x,y);
  4500 
  4501 
  4502 *** Internal programming interfaces ***
  4503 
  4504 * tuned simplifier trace output; new flag debug_simp;
  4505 
  4506 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4507 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4508 
  4509 * AxClass.axclass_tac lost the theory argument;
  4510 
  4511 * tuned current_goals_markers semantics: begin / end goal avoids
  4512 printing empty lines;
  4513 
  4514 * removed prs and prs_fn hook, which was broken because it did not
  4515 include \n in its semantics, forcing writeln to add one
  4516 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4517 string -> unit if you really want to output text without newline;
  4518 
  4519 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4520 plain output, interface builders may have to enable 'isabelle_font'
  4521 mode to get Isabelle font glyphs as before;
  4522 
  4523 * refined token_translation interface; INCOMPATIBILITY: output length
  4524 now of type real instead of int;
  4525 
  4526 * theory loader actions may be traced via new ThyInfo.add_hook
  4527 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4528 your own database of information attached to *whole* theories -- as
  4529 opposed to intra-theory data slots offered via TheoryDataFun;
  4530 
  4531 * proper handling of dangling sort hypotheses (at last!);
  4532 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4533 extra sort hypotheses that can be witnessed from the type signature;
  4534 the force_strip_shyps flag is gone, any remaining shyps are simply
  4535 left in the theorem (with a warning issued by strip_shyps_warning);
  4536 
  4537 
  4538 
  4539 New in Isabelle98-1 (October 1998)
  4540 ----------------------------------
  4541 
  4542 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4543 
  4544 * several changes of automated proof tools;
  4545 
  4546 * HOL: major changes to the inductive and datatype packages, including
  4547 some minor incompatibilities of theory syntax;
  4548 
  4549 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4550 called `inj_on';
  4551 
  4552 * HOL: removed duplicate thms in Arith:
  4553   less_imp_add_less  should be replaced by  trans_less_add1
  4554   le_imp_add_le      should be replaced by  trans_le_add1
  4555 
  4556 * HOL: unary minus is now overloaded (new type constraints may be
  4557 required);
  4558 
  4559 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4560 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4561 now taken as an integer constant.
  4562 
  4563 * Pure: ML function 'theory_of' renamed to 'theory';
  4564 
  4565 
  4566 *** Proof tools ***
  4567 
  4568 * Simplifier:
  4569   1. Asm_full_simp_tac is now more aggressive.
  4570      1. It will sometimes reorient premises if that increases their power to
  4571         simplify.
  4572      2. It does no longer proceed strictly from left to right but may also
  4573         rotate premises to achieve further simplification.
  4574      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4575      old Asm_full_simp_tac in that it does not rotate premises.
  4576   2. The simplifier now knows a little bit about nat-arithmetic.
  4577 
  4578 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4579 allows for selected deletion of wrappers, by introduction of names for
  4580 wrapper functionals.  This implies that addbefore, addSbefore,
  4581 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4582 and that adding two tactics with the same name overwrites the first
  4583 one (emitting a warning).
  4584   type wrapper = (int -> tactic) -> (int -> tactic)
  4585   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4586   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4587   delWrapper, delSWrapper: claset *  string            -> claset
  4588   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4589 
  4590 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4591 semantics; addbefore now affects only the unsafe part of step_tac
  4592 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4593 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4594 by Force_tac;
  4595 
  4596 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4597 compWrapper; added safe wrapper (and access functions for it);
  4598 
  4599 * HOL/split_all_tac is now much faster and fails if there is nothing
  4600 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4601 and the names of the automatically generated variables have changed.
  4602 split_all_tac has moved within claset() from unsafe wrappers to safe
  4603 wrappers, which means that !!-bound variables are split much more
  4604 aggressively, and safe_tac and clarify_tac now split such variables.
  4605 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4606 Note: the same holds for record_split_tac, which does the job of
  4607 split_all_tac for record fields.
  4608 
  4609 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4610 permanently to the default simpset using Addsplits just like
  4611 Addsimps. They can be removed via Delsplits just like
  4612 Delsimps. Lower-case versions are also available.
  4613 
  4614 * HOL/Simplifier: The rule split_if is now part of the default
  4615 simpset. This means that the simplifier will eliminate all occurrences
  4616 of if-then-else in the conclusion of a goal. To prevent this, you can
  4617 either remove split_if completely from the default simpset by
  4618 `Delsplits [split_if]' or remove it in a specific call of the
  4619 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4620 other case splitting rules to/from the default simpset: every datatype
  4621 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4622 t is the name of the datatype).
  4623 
  4624 * Classical reasoner / Simplifier combination: new force_tac (and
  4625 derivatives Force_tac, force) combines rewriting and classical
  4626 reasoning (and whatever other tools) similarly to auto_tac, but is
  4627 aimed to solve the given subgoal completely.
  4628 
  4629 
  4630 *** General ***
  4631 
  4632 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4633 and `goalw': the theory is no longer needed as an explicit argument -
  4634 the current theory context is used; assumptions are no longer returned
  4635 at the ML-level unless one of them starts with ==> or !!; it is
  4636 recommended to convert to these new commands using isatool fixgoal
  4637 (backup your sources first!);
  4638 
  4639 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4640 the current theory context, and 'theory' to lookup stored theories;
  4641 
  4642 * new theory section 'locale' for declaring constants, assumptions and
  4643 definitions that have local scope;
  4644 
  4645 * new theory section 'nonterminals' for purely syntactic types;
  4646 
  4647 * new theory section 'setup' for generic ML setup functions
  4648 (e.g. package initialization);
  4649 
  4650 * the distribution now includes Isabelle icons: see
  4651 lib/logo/isabelle-{small,tiny}.xpm;
  4652 
  4653 * isatool install - install binaries with absolute references to
  4654 ISABELLE_HOME/bin;
  4655 
  4656 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4657 
  4658 * print mode 'emacs' reserved for Isamode;
  4659 
  4660 * support multiple print (ast) translations per constant name;
  4661 
  4662 * theorems involving oracles are now printed with a suffixed [!];
  4663 
  4664 
  4665 *** HOL ***
  4666 
  4667 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4668 
  4669 * HOL/inductive package reorganized and improved: now supports mutual
  4670 definitions such as
  4671 
  4672   inductive EVEN ODD
  4673     intrs
  4674       null "0 : EVEN"
  4675       oddI "n : EVEN ==> Suc n : ODD"
  4676       evenI "n : ODD ==> Suc n : EVEN"
  4677 
  4678 new theorem list "elims" contains an elimination rule for each of the
  4679 recursive sets; inductive definitions now handle disjunctive premises
  4680 correctly (also ZF);
  4681 
  4682 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4683 "mutual_induct" no longer exists - the induction rule is always
  4684 contained in "induct";
  4685 
  4686 
  4687 * HOL/datatype package re-implemented and greatly improved: now
  4688 supports mutually recursive datatypes such as
  4689 
  4690   datatype
  4691     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4692             | SUM ('a aexp) ('a aexp)
  4693             | DIFF ('a aexp) ('a aexp)
  4694             | NUM 'a
  4695   and
  4696     'a bexp = LESS ('a aexp) ('a aexp)
  4697             | AND ('a bexp) ('a bexp)
  4698             | OR ('a bexp) ('a bexp)
  4699 
  4700 as well as indirectly recursive datatypes such as
  4701 
  4702   datatype
  4703     ('a, 'b) term = Var 'a
  4704                   | App 'b ((('a, 'b) term) list)
  4705 
  4706 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4707 induction on mutually / indirectly recursive datatypes.
  4708 
  4709 Primrec equations are now stored in theory and can be accessed via
  4710 <function_name>.simps.
  4711 
  4712 INCOMPATIBILITIES:
  4713 
  4714   - Theories using datatypes must now have theory Datatype as an
  4715     ancestor.
  4716   - The specific <typename>.induct_tac no longer exists - use the
  4717     generic induct_tac instead.
  4718   - natE has been renamed to nat.exhaust - use exhaust_tac
  4719     instead of res_inst_tac ... natE. Note that the variable
  4720     names in nat.exhaust differ from the names in natE, this
  4721     may cause some "fragile" proofs to fail.
  4722   - The theorems split_<typename>_case and split_<typename>_case_asm
  4723     have been renamed to <typename>.split and <typename>.split_asm.
  4724   - Since default sorts of type variables are now handled correctly,
  4725     some datatype definitions may have to be annotated with explicit
  4726     sort constraints.
  4727   - Primrec definitions no longer require function name and type
  4728     of recursive argument.
  4729 
  4730 Consider using isatool fixdatatype to adapt your theories and proof
  4731 scripts to the new package (backup your sources first!).
  4732 
  4733 
  4734 * HOL/record package: considerably improved implementation; now
  4735 includes concrete syntax for record types, terms, updates; theorems
  4736 for surjective pairing and splitting !!-bound record variables; proof
  4737 support is as follows:
  4738 
  4739   1) standard conversions (selectors or updates applied to record
  4740 constructor terms) are part of the standard simpset;
  4741 
  4742   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4743 made part of standard simpset and claset via addIffs;
  4744 
  4745   3) a tactic for record field splitting (record_split_tac) is part of
  4746 the standard claset (addSWrapper);
  4747 
  4748 To get a better idea about these rules you may retrieve them via
  4749 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4750 the name of your record type.
  4751 
  4752 The split tactic 3) conceptually simplifies by the following rule:
  4753 
  4754   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4755 
  4756 Thus any record variable that is bound by meta-all will automatically
  4757 blow up into some record constructor term, consequently the
  4758 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4759 solve record problems automatically.
  4760 
  4761 
  4762 * reorganized the main HOL image: HOL/Integ and String loaded by
  4763 default; theory Main includes everything;
  4764 
  4765 * automatic simplification of integer sums and comparisons, using cancellation;
  4766 
  4767 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4768 
  4769 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4770 
  4771 * many new identities for unions, intersections, set difference, etc.;
  4772 
  4773 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4774 called split_if, split_split, split_sum_case and split_nat_case (to go
  4775 with add/delsplits);
  4776 
  4777 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4778 (?x::unit) = (); this is made part of the default simpset, which COULD
  4779 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4780 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4781 unit_abs_eta_conv is added in order to counter the effect of
  4782 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4783 %u.f();
  4784 
  4785 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4786 makes more sense);
  4787 
  4788 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4789   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4790   disjointness reasoning but breaking a few old proofs.
  4791 
  4792 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4793 to 'converse' from 'inverse' (for compatibility with ZF and some
  4794 literature);
  4795 
  4796 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4797 the well-founded relation;
  4798 
  4799 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4800     Compl A.  The "Compl" syntax remains available as input syntax for this
  4801     release ONLY.
  4802 
  4803 * HOL/Update: new theory of function updates:
  4804     f(a:=b) == %x. if x=a then b else f x
  4805 may also be iterated as in f(a:=b,c:=d,...);
  4806 
  4807 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4808 
  4809 * HOL/List:
  4810   - new function list_update written xs[i:=v] that updates the i-th
  4811     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4812   - new function `upt' written [i..j(] which generates the list
  4813     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4814     bound write [i..j], which is a shorthand for [i..j+1(].
  4815   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4816 
  4817 * HOL/Arith:
  4818   - removed 'pred' (predecessor) function;
  4819   - generalized some theorems about n-1;
  4820   - many new laws about "div" and "mod";
  4821   - new laws about greatest common divisors (see theory ex/Primes);
  4822 
  4823 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4824 instead of "inverse";
  4825 
  4826 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4827   of the multiset ordering;
  4828 
  4829 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4830   (not included by default);
  4831 
  4832 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4833 
  4834 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4835   programs, i.e. different program variables may have different types.
  4836 
  4837 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4838   [previously, this check worked only if the rewrite rule was unconditional]
  4839   Now rew can involve either definitions or equalities (either == or =).
  4840 
  4841 
  4842 *** ZF ***
  4843 
  4844 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4845   only the theorems proved on ZF.ML;
  4846 
  4847 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4848   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4849   disjointness reasoning but breaking a few old proofs.
  4850 
  4851 * ZF/Update: new theory of function updates
  4852     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4853   may also be iterated as in f(a:=b,c:=d,...);
  4854 
  4855 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4856 
  4857 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4858   [previously, this check worked only if the rewrite rule was unconditional]
  4859   Now rew can involve either definitions or equalities (either == or =).
  4860 
  4861 * case_tac provided for compatibility with HOL
  4862     (like the old excluded_middle_tac, but with subgoals swapped)
  4863 
  4864 
  4865 *** Internal programming interfaces ***
  4866 
  4867 * Pure: several new basic modules made available for general use, see
  4868 also src/Pure/README;
  4869 
  4870 * improved the theory data mechanism to support encapsulation (data
  4871 kind name replaced by private Object.kind, acting as authorization
  4872 key); new type-safe user interface via functor TheoryDataFun; generic
  4873 print_data function becomes basically useless;
  4874 
  4875 * removed global_names compatibility flag -- all theory declarations
  4876 are qualified by default;
  4877 
  4878 * module Pure/Syntax now offers quote / antiquote translation
  4879 functions (useful for Hoare logic etc. with implicit dependencies);
  4880 see HOL/ex/Antiquote for an example use;
  4881 
  4882 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4883 cterm -> thm;
  4884 
  4885 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4886 subgoal;
  4887 
  4888 * Display.print_goals function moved to Locale.print_goals;
  4889 
  4890 * standard print function for goals supports current_goals_markers
  4891 variable for marking begin of proof, end of proof, start of goal; the
  4892 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4893 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4894 for example;
  4895 
  4896 
  4897 
  4898 New in Isabelle98 (January 1998)
  4899 --------------------------------
  4900 
  4901 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4902 
  4903 * changed lexical syntax of terms / types: dots made part of long
  4904 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4905 
  4906 * simpset (and claset) reference variable replaced by functions
  4907 simpset / simpset_ref;
  4908 
  4909 * no longer supports theory aliases (via merge) and non-trivial
  4910 implicit merge of thms' signatures;
  4911 
  4912 * most internal names of constants changed due to qualified names;
  4913 
  4914 * changed Pure/Sequence interface (see Pure/seq.ML);
  4915 
  4916 
  4917 *** General Changes ***
  4918 
  4919 * hierachically structured name spaces (for consts, types, axms, thms
  4920 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4921 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4922 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4923 long_names for fully qualified output names; NOTE: ML programs
  4924 (special tactics, packages etc.) referring to internal names may have
  4925 to be adapted to cope with fully qualified names; in case of severe
  4926 backward campatibility problems try setting 'global_names' at compile
  4927 time to have enrything declared within a flat name space; one may also
  4928 fine tune name declarations in theories via the 'global' and 'local'
  4929 section;
  4930 
  4931 * reimplemented the implicit simpset and claset using the new anytype
  4932 data filed in signatures; references simpset:simpset ref etc. are
  4933 replaced by functions simpset:unit->simpset and
  4934 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4935 to patch your ML files accordingly;
  4936 
  4937 * HTML output now includes theory graph data for display with Java
  4938 applet or isatool browser; data generated automatically via isatool
  4939 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4940 
  4941 * defs may now be conditional; improved rewrite_goals_tac to handle
  4942 conditional equations;
  4943 
  4944 * defs now admits additional type arguments, using TYPE('a) syntax;
  4945 
  4946 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4947 creates a new theory node; implicit merge of thms' signatures is
  4948 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4949 transfer:theory->thm->thm in (rare) cases;
  4950 
  4951 * improved handling of draft signatures / theories; draft thms (and
  4952 ctyps, cterms) are automatically promoted to real ones;
  4953 
  4954 * slightly changed interfaces for oracles: admit many per theory, named
  4955 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4956 
  4957 * print_goals: optional output of const types (set show_consts and
  4958 show_types);
  4959 
  4960 * improved output of warnings (###) and errors (***);
  4961 
  4962 * subgoal_tac displays a warning if the new subgoal has type variables;
  4963 
  4964 * removed old README and Makefiles;
  4965 
  4966 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4967 
  4968 * removed obsolete init_pps and init_database;
  4969 
  4970 * deleted the obsolete tactical STATE, which was declared by
  4971     fun STATE tacfun st = tacfun st st;
  4972 
  4973 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4974 (which abbreviates $HOME);
  4975 
  4976 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4977 use isatool fixseq to adapt your ML programs (this works for fully
  4978 qualified references to the Sequence structure only!);
  4979 
  4980 * use_thy no longer requires writable current directory; it always
  4981 reloads .ML *and* .thy file, if either one is out of date;
  4982 
  4983 
  4984 *** Classical Reasoner ***
  4985 
  4986 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4987 tactics that use classical reasoning to simplify a subgoal without
  4988 splitting it into several subgoals;
  4989 
  4990 * Safe_tac: like safe_tac but uses the default claset;
  4991 
  4992 
  4993 *** Simplifier ***
  4994 
  4995 * added simplification meta rules:
  4996     (asm_)(full_)simplify: simpset -> thm -> thm;
  4997 
  4998 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4999 logics (again);
  5000 
  5001 * added prems argument to simplification procedures;
  5002 
  5003 * HOL, FOL, ZF: added infix function `addsplits':
  5004   instead of `<simpset> setloop (split_tac <thms>)'
  5005   you can simply write `<simpset> addsplits <thms>'
  5006 
  5007 
  5008 *** Syntax ***
  5009 
  5010 * TYPE('a) syntax for type reflection terms;
  5011 
  5012 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5013 
  5014 * pretty printer: changed order of mixfix annotation preference (again!);
  5015 
  5016 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5017 
  5018 
  5019 *** HOL ***
  5020 
  5021 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5022   with `addloop' of the simplifier to faciliate case splitting in premises.
  5023 
  5024 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5025 
  5026 * HOL/Auth: new protocol proofs including some for the Internet
  5027   protocol TLS;
  5028 
  5029 * HOL/Map: new theory of `maps' a la VDM;
  5030 
  5031 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5032 cancelling out common nat summands from =, <, <= (in)equalities, or
  5033 differences; simplification procedures nat_cancel_factor for
  5034 cancelling common factor from =, <, <= (in)equalities over natural
  5035 sums; nat_cancel contains both kinds of procedures, it is installed by
  5036 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5037 
  5038 * HOL/simplifier: terms of the form
  5039   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5040   are rewritten to
  5041   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5042   and those of the form
  5043   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5044   are rewritten to
  5045   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5046 
  5047 * HOL/datatype
  5048   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5049 
  5050   P(t_case f1 ... fn x) =
  5051      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5052         ...
  5053        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5054      )
  5055 
  5056   and a theorem `split_t_case_asm' of the form
  5057 
  5058   P(t_case f1 ... fn x) =
  5059     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5060         ...
  5061        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5062      )
  5063   which can be added to a simpset via `addsplits'. The existing theorems
  5064   expand_list_case and expand_option_case have been renamed to
  5065   split_list_case and split_option_case.
  5066 
  5067 * HOL/Arithmetic:
  5068   - `pred n' is automatically converted to `n-1'.
  5069     Users are strongly encouraged not to use `pred' any longer,
  5070     because it will disappear altogether at some point.
  5071   - Users are strongly encouraged to write "0 < n" rather than
  5072     "n ~= 0". Theorems and proof tools have been modified towards this
  5073     `standard'.
  5074 
  5075 * HOL/Lists:
  5076   the function "set_of_list" has been renamed "set" (and its theorems too);
  5077   the function "nth" now takes its arguments in the reverse order and
  5078   has acquired the infix notation "!" as in "xs!n".
  5079 
  5080 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5081 
  5082 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5083   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5084 
  5085 * HOL/record: extensible records with schematic structural subtyping
  5086 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5087 still lacks various theorems and concrete record syntax;
  5088 
  5089 
  5090 *** HOLCF ***
  5091 
  5092 * removed "axioms" and "generated by" sections;
  5093 
  5094 * replaced "ops" section by extended "consts" section, which is capable of
  5095   handling the continuous function space "->" directly;
  5096 
  5097 * domain package:
  5098   . proves theorems immediately and stores them in the theory,
  5099   . creates hierachical name space,
  5100   . now uses normal mixfix annotations (instead of cinfix...),
  5101   . minor changes to some names and values (for consistency),
  5102   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5103   . separator between mutual domain defs: changed "," to "and",
  5104   . improved handling of sort constraints;  now they have to
  5105     appear on the left-hand side of the equations only;
  5106 
  5107 * fixed LAM <x,y,zs>.b syntax;
  5108 
  5109 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5110 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5111 
  5112 
  5113 *** FOL and ZF ***
  5114 
  5115 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5116   with `addloop' of the simplifier to faciliate case splitting in premises.
  5117 
  5118 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5119 in HOL, they strip ALL and --> from proved theorems;
  5120 
  5121 
  5122 
  5123 New in Isabelle94-8 (May 1997)
  5124 ------------------------------
  5125 
  5126 *** General Changes ***
  5127 
  5128 * new utilities to build / run / maintain Isabelle etc. (in parts
  5129 still somewhat experimental); old Makefiles etc. still functional;
  5130 
  5131 * new 'Isabelle System Manual';
  5132 
  5133 * INSTALL text, together with ./configure and ./build scripts;
  5134 
  5135 * reimplemented type inference for greater efficiency, better error
  5136 messages and clean internal interface;
  5137 
  5138 * prlim command for dealing with lots of subgoals (an easier way of
  5139 setting goals_limit);
  5140 
  5141 
  5142 *** Syntax ***
  5143 
  5144 * supports alternative (named) syntax tables (parser and pretty
  5145 printer); internal interface is provided by add_modesyntax(_i);
  5146 
  5147 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5148 be used in conjunction with the Isabelle symbol font; uses the
  5149 "symbols" syntax table;
  5150 
  5151 * added token_translation interface (may translate name tokens in
  5152 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5153 the current print_mode); IMPORTANT: user print translation functions
  5154 are responsible for marking newly introduced bounds
  5155 (Syntax.mark_boundT);
  5156 
  5157 * token translations for modes "xterm" and "xterm_color" that display
  5158 names in bold, underline etc. or colors (which requires a color
  5159 version of xterm);
  5160 
  5161 * infixes may now be declared with names independent of their syntax;
  5162 
  5163 * added typed_print_translation (like print_translation, but may
  5164 access type of constant);
  5165 
  5166 
  5167 *** Classical Reasoner ***
  5168 
  5169 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5170 some limitations.  Blast_tac...
  5171   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5172   + ignores elimination rules that don't have the correct format
  5173         (the conclusion MUST be a formula variable)
  5174   + ignores types, which can make HOL proofs fail
  5175   + rules must not require higher-order unification, e.g. apply_type in ZF
  5176     [message "Function Var's argument not a bound variable" relates to this]
  5177   + its proof strategy is more general but can actually be slower
  5178 
  5179 * substitution with equality assumptions no longer permutes other
  5180 assumptions;
  5181 
  5182 * minor changes in semantics of addafter (now called addaltern); renamed
  5183 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5184 (and access functions for it);
  5185 
  5186 * improved combination of classical reasoner and simplifier:
  5187   + functions for handling clasimpsets
  5188   + improvement of addss: now the simplifier is called _after_ the
  5189     safe steps.
  5190   + safe variant of addss called addSss: uses safe simplifications
  5191     _during_ the safe steps. It is more complete as it allows multiple
  5192     instantiations of unknowns (e.g. with slow_tac).
  5193 
  5194 *** Simplifier ***
  5195 
  5196 * added interface for simplification procedures (functions that
  5197 produce *proven* rewrite rules on the fly, depending on current
  5198 redex);
  5199 
  5200 * ordering on terms as parameter (used for ordered rewriting);
  5201 
  5202 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5203 
  5204 * the solver is now split into a safe and an unsafe part.
  5205 This should be invisible for the normal user, except that the
  5206 functions setsolver and addsolver have been renamed to setSolver and
  5207 addSolver; added safe_asm_full_simp_tac;
  5208 
  5209 
  5210 *** HOL ***
  5211 
  5212 * a generic induction tactic `induct_tac' which works for all datatypes and
  5213 also for type `nat';
  5214 
  5215 * a generic case distinction tactic `exhaust_tac' which works for all
  5216 datatypes and also for type `nat';
  5217 
  5218 * each datatype comes with a function `size';
  5219 
  5220 * patterns in case expressions allow tuple patterns as arguments to
  5221 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5222 
  5223 * primrec now also works with type nat;
  5224 
  5225 * recdef: a new declaration form, allows general recursive functions to be
  5226 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5227 
  5228 * the constant for negation has been renamed from "not" to "Not" to
  5229 harmonize with FOL, ZF, LK, etc.;
  5230 
  5231 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5232 infinite lists;
  5233 
  5234 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5235 
  5236 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5237 problems in commutative rings, using axiomatic type classes for + and *;
  5238 
  5239 * more examples in HOL/MiniML and HOL/Auth;
  5240 
  5241 * more default rewrite rules for quantifiers, union/intersection;
  5242 
  5243 * a new constant `arbitrary == @x.False';
  5244 
  5245 * HOLCF/IOA replaces old HOL/IOA;
  5246 
  5247 * HOLCF changes: derived all rules and arities
  5248   + axiomatic type classes instead of classes
  5249   + typedef instead of faking type definitions
  5250   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5251   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5252   + eliminated the types void, one, tr
  5253   + use unit lift and bool lift (with translations) instead of one and tr
  5254   + eliminated blift from Lift3.thy (use Def instead of blift)
  5255   all eliminated rules are derived as theorems --> no visible changes ;
  5256 
  5257 
  5258 *** ZF ***
  5259 
  5260 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5261 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5262 as ZF_cs addSIs [equalityI];
  5263 
  5264 
  5265 
  5266 New in Isabelle94-7 (November 96)
  5267 ---------------------------------
  5268 
  5269 * allowing negative levels (as offsets) in prlev and choplev;
  5270 
  5271 * super-linear speedup for large simplifications;
  5272 
  5273 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5274 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5275 FAIL); can suppress it using the command Delsimps (ex_simps @
  5276 all_simps); De Morgan laws are also now included, by default;
  5277 
  5278 * improved printing of ==>  :  ~:
  5279 
  5280 * new object-logic "Sequents" adds linear logic, while replacing LK
  5281 and Modal (thanks to Sara Kalvala);
  5282 
  5283 * HOL/Auth: correctness proofs for authentication protocols;
  5284 
  5285 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5286 examples on HOL/Auth);
  5287 
  5288 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5289 the rewriter and classical reasoner simultaneously;
  5290 
  5291 * function uresult no longer returns theorems in "standard" format;
  5292 regain previous version by: val uresult = standard o uresult;
  5293 
  5294 
  5295 
  5296 New in Isabelle94-6
  5297 -------------------
  5298 
  5299 * oracles -- these establish an interface between Isabelle and trusted
  5300 external reasoners, which may deliver results as theorems;
  5301 
  5302 * proof objects (in particular record all uses of oracles);
  5303 
  5304 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5305 
  5306 * "constdefs" section in theory files;
  5307 
  5308 * "primrec" section (HOL) no longer requires names;
  5309 
  5310 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5311 
  5312 
  5313 
  5314 New in Isabelle94-5
  5315 -------------------
  5316 
  5317 * reduced space requirements;
  5318 
  5319 * automatic HTML generation from theories;
  5320 
  5321 * theory files no longer require "..." (quotes) around most types;
  5322 
  5323 * new examples, including two proofs of the Church-Rosser theorem;
  5324 
  5325 * non-curried (1994) version of HOL is no longer distributed;
  5326 
  5327 
  5328 
  5329 New in Isabelle94-4
  5330 -------------------
  5331 
  5332 * greatly reduced space requirements;
  5333 
  5334 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5335 
  5336 * searchable theorem database (see the section "Retrieving theorems" on
  5337 page 8 of the Reference Manual);
  5338 
  5339 * new examples, including Grabczewski's monumental case study of the
  5340 Axiom of Choice;
  5341 
  5342 * The previous version of HOL renamed to Old_HOL;
  5343 
  5344 * The new version of HOL (previously called CHOL) uses a curried syntax
  5345 for functions.  Application looks like f a b instead of f(a,b);
  5346 
  5347 * Mutually recursive inductive definitions finally work in HOL;
  5348 
  5349 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5350 translates to the operator "split";
  5351 
  5352 
  5353 
  5354 New in Isabelle94-3
  5355 -------------------
  5356 
  5357 * new infix operator, addss, allowing the classical reasoner to
  5358 perform simplification at each step of its search.  Example:
  5359         fast_tac (cs addss ss)
  5360 
  5361 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5362 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5363 look like (a,b) instead of <a,b>;
  5364 
  5365 * PLEASE NOTE: CHOL will eventually replace HOL!
  5366 
  5367 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5368 It translates to the operator "split".  A new theory of integers is available;
  5369 
  5370 * In ZF, integer numerals now denote two's-complement binary integers.
  5371 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5372 
  5373 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5374 of the Axiom of Choice;
  5375 
  5376 
  5377 
  5378 New in Isabelle94-2
  5379 -------------------
  5380 
  5381 * Significantly faster resolution;
  5382 
  5383 * the different sections in a .thy file can now be mixed and repeated
  5384 freely;
  5385 
  5386 * Database of theorems for FOL, HOL and ZF.  New
  5387 commands including qed, qed_goal and bind_thm store theorems in the database.
  5388 
  5389 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5390 a given theory (thms_of), or find out what theory a theorem was proved in
  5391 (theory_of_thm);
  5392 
  5393 * Bugs fixed in the inductive definition and datatype packages;
  5394 
  5395 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5396 and HOL_dup_cs obsolete;
  5397 
  5398 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5399 have been removed;
  5400 
  5401 * Simpler definition of function space in ZF;
  5402 
  5403 * new results about cardinal and ordinal arithmetic in ZF;
  5404 
  5405 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5406 types;
  5407 
  5408 :mode=text:wrap=hard:maxLineLen=72:
  5409 
  5410 $Id$