NEWS
author wenzelm
Mon May 12 22:03:33 2008 +0200 (2008-05-12)
changeset 26874 b2daa27fc0a7
parent 26765 f2ea56490bfb
child 26877 c3bb1f397811
permissions -rw-r--r--
misc tuning;
     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 * Locale proofs: default proof step now includes 'unfold_locales';
   101 hence 'proof' without argument may be used to unfold locale
   102 predicates.
   103 
   104 
   105 *** Document preparation ***
   106 
   107 * Antiquotation "lemma" takes a proposition and a simple method text
   108 as argument and asserts that the proposition is provable by the
   109 corresponding method invocation.  Prints text of proposition, as does
   110 antiquotation "prop".  A simple method text is either a method name or
   111 a method name plus (optional) method arguments in parentheses,
   112 mimicking the conventions known from Isar proof text.  Useful for
   113 illustration of presented theorems by particular examples.
   114 
   115 
   116 *** HOL ***
   117 
   118 * Merged theories Wellfounded_Recursion, Accessible_Part and
   119 Wellfounded_Relations to "Wellfounded.thy".
   120 
   121 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   122 
   123 * Class finite no longer treats UNIV as class parameter.  Use class
   124 enum from theory Library/Enum instead to achieve a similar effect.
   125 INCOMPATIBILITY.
   126 
   127 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   128 and "Cons".  INCOMPATIBILITY.
   129 
   130 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   131 Potential INCOMPATIBILITY.
   132 
   133 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   134 injective_fst_snd removed, use split_eta and prod_eqI instead.
   135 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   136 
   137 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   138 the same name in theory Orderings:
   139 
   140   less_trans
   141   less_linear
   142   le_imp_less_or_eq
   143   le_less_trans
   144   less_le_trans
   145   less_not_sym
   146   less_asym
   147 
   148 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   149 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   150 and different variable names.
   151 
   152 * Library/Option_ord.thy: Canonical order on option type.
   153 
   154 * Library/RBT.thy: New theory of red-black trees, an efficient
   155 implementation of finite maps.
   156 
   157 * Library/Countable.thy: Type class for countable types.
   158 
   159 * Theory Int: The representation of numerals has changed.  The infix
   160 operator BIT and the bit datatype with constructors B0 and B1 have
   161 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   162 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   163 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   164 accordingly.
   165 
   166 * Theory Nat: definition of <= and < on natural numbers no longer
   167 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   168 le_def and less_def have disappeared.  Consider lemmas not_less
   169 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   170 
   171 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   172 (whose purpose mainly is for various fold_set functionals) have been
   173 abandoned in favor of the existing algebraic classes
   174 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   175 lower_semilattice (resp. upper_semilattice) and linorder.
   176 INCOMPATIBILITY.
   177 
   178 * Theory Transitive_Closure: induct and cases rules now declare proper
   179 case_names ("base" and "step").  INCOMPATIBILITY.
   180 
   181 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   182 lattices.  The form set-specific version is available as
   183 Inductive.lfp_ordinal_induct_set.
   184 
   185 * Renamed theorems "power.simps" to "power_int.simps".
   186 
   187 * Class semiring_div provides basic abstract properties of semirings
   188 with division and modulo operations.  Subsumes former class dvd_mod.
   189 
   190 * Merged theories IntDef, Numeral and IntArith into unified theory
   191 Int.  INCOMPATIBILITY.
   192 
   193 * Theory Library/Code_Index: type "index" now represents natural
   194 numbers rather than integers.  INCOMPATIBILITY.
   195 
   196 * New class "uminus" with operation "uminus" (split of from class
   197 "minus" which now only has operation "minus", binary).
   198 INCOMPATIBILITY.
   199 
   200 * New primrec package.  Specification syntax conforms in style to
   201 definition/function/....  No separate induction rule is provided.  The
   202 "primrec" command distinguishes old-style and new-style specifications
   203 by syntax.  The former primrec package is now named OldPrimrecPackage.
   204 When adjusting theories, beware: constants stemming from new-style
   205 primrec specifications have authentic syntax.
   206 
   207 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   208 
   209 * Library/ListVector: new theory of arithmetic vector operations.
   210 
   211 * Library/Order_Relation: new theory of various orderings as sets of
   212 pairs.  Defines preorders, partial orders, linear orders and
   213 well-orders on sets and on types.
   214 
   215 * Constants "card", "internal_split", "option_map" now with authentic
   216 syntax.  INCOMPATIBILITY.
   217 
   218 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   219 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   220 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   221 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   222 Sup_set_def, le_def, less_def, option_map_def now with object
   223 equality.  INCOMPATIBILITY.
   224 
   225 * Method "induction_scheme" derives user-specified induction rules
   226 from well-founded induction and completeness of patterns. This factors
   227 out some operations that are done internally by the function package
   228 and makes them available separately. See "HOL/ex/Induction_Scheme.thy"
   229 for examples,
   230 
   231 * Records. Removed K_record, and replaced it by pure lambda term
   232 %x. c. The simplifier setup is now more robust against eta expansion.
   233 INCOMPATIBILITY: in cases explicitly referring to K_record.
   234 
   235 * Metis prover is now an order of magnitude faster, and also works
   236 with multithreading.
   237 
   238 * Metis: the maximum number of clauses that can be produced from a
   239 theorem is now given by the attribute max_clauses. Theorems that
   240 exceed this number are ignored, with a warning printed.
   241 
   242 * Sledgehammer no longer produces structured proofs by default. To
   243 enable, declare [[sledgehammer_full = true]]. Attributes
   244 reconstruction_modulus, reconstruction_sorts renamed
   245 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   246 
   247 
   248 *** ZF ***
   249 
   250 * Renamed some theories to allow to loading both ZF and HOL in the
   251 same session:
   252 
   253   Datatype  -> Datatype_ZF
   254   Inductive -> Inductive_ZF
   255   Int       -> Int_ZF
   256   IntDiv    -> IntDiv_ZF
   257   Nat       -> Nat_ZF
   258   List      -> List_ZF
   259   Main      -> Main_ZF
   260 
   261 INCOMPATIBILITY: ZF theories that import individual theories below
   262 Main might need to be adapted.  Regular theory Main is still
   263 available, as trivial extension of Main_ZF.
   264 
   265 
   266 *** ML ***
   267 
   268 * Functor NamedThmsFun: data is available to the user as dynamic fact
   269 (of the same name).  Removed obsolete print command.
   270 
   271 * Removed obsolete "use_legacy_bindings" function.  INCOMPATIBILITY.
   272 
   273 * ML within Isar: antiquotation @{const name} or @{const
   274 name(typargs)} produces statically-checked Const term.
   275 
   276 * The ``print mode'' is now a thread-local value derived from a global
   277 template (the former print_mode reference), thus access becomes
   278 non-critical.  The global print_mode reference is for session
   279 management only; user-code should use print_mode_value,
   280 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   281 
   282 * Functions system/system_out provide a robust way to invoke external
   283 shell commands, with propagation of interrupts (after Poly/ML 5.2).
   284 Do not use OS.Process.system etc. from the basis library!
   285 
   286 
   287 *** System ***
   288 
   289 * YXML notation provides a simple and efficient alternative to
   290 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   291 isatool yxml as described in the Isabelle system manual.
   292 
   293 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   294 way of changing the user's settings is via
   295 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   296 script.
   297 
   298 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   299 in accordance with Proof General 3.7, which prefers GNU emacs.
   300 
   301 * Multithreading.max_threads := 0 refers to the number of actual CPU
   302 cores of the underlying machine, which is a good starting point for
   303 optimal performance tuning.  The corresponding usedir option -M allows
   304 "max" as an alias for "0".  WARNING: does not work on certain versions
   305 of Mac OS (with Poly/ML 5.1).
   306 
   307 * isatool tty runs Isabelle process with plain tty interaction;
   308 optional line editor may be specified via ISABELLE_LINE_EDITOR
   309 setting, the default settings attempt to locate "ledit" and "rlwrap".
   310 
   311 * isatool browser now works with Cygwin as well, using general
   312 "javapath" function defined in Isabelle process environment.
   313 
   314 * isabelle-process: non-ML sessions are run with "nice", to prevent
   315 Isabelle from flooding interactive front-ends (notably ProofGeneral /
   316 XEmacs).
   317 
   318 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   319 provides general wrapper for managing an Isabelle process in a robust
   320 fashion, with ``cooked'' output from stdin/stderr.
   321 
   322 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   323 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   324 
   325 
   326 
   327 New in Isabelle2007 (November 2007)
   328 -----------------------------------
   329 
   330 *** General ***
   331 
   332 * More uniform information about legacy features, notably a
   333 warning/error of "Legacy feature: ...", depending on the state of the
   334 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   335 legacy features will disappear eventually.
   336 
   337 * Theory syntax: the header format ``theory A = B + C:'' has been
   338 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   339 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   340 
   341 * Theory syntax: the old non-Isar theory file format has been
   342 discontinued altogether.  Note that ML proof scripts may still be used
   343 with Isar theories; migration is usually quite simple with the ML
   344 function use_legacy_bindings.  INCOMPATIBILITY.
   345 
   346 * Theory syntax: some popular names (e.g. 'class', 'declaration',
   347 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
   348 quotes.
   349 
   350 * Theory loader: be more serious about observing the static theory
   351 header specifications (including optional directories), but not the
   352 accidental file locations of previously successful loads.  The strict
   353 update policy of former update_thy is now already performed by
   354 use_thy, so the former has been removed; use_thys updates several
   355 theories simultaneously, just as 'imports' within a theory header
   356 specification, but without merging the results.  Potential
   357 INCOMPATIBILITY: may need to refine theory headers and commands
   358 ROOT.ML which depend on load order.
   359 
   360 * Theory loader: optional support for content-based file
   361 identification, instead of the traditional scheme of full physical
   362 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
   363 (cf. the system manual).  The new scheme allows to work with
   364 non-finished theories in persistent session images, such that source
   365 files may be moved later on without requiring reloads.
   366 
   367 * Theory loader: old-style ML proof scripts being *attached* to a thy
   368 file (with the same base name as the theory) are considered a legacy
   369 feature, which will disappear eventually. Even now, the theory loader
   370 no longer maintains dependencies on such files.
   371 
   372 * Syntax: the scope for resolving ambiguities via type-inference is
   373 now limited to individual terms, instead of whole simultaneous
   374 specifications as before. This greatly reduces the complexity of the
   375 syntax module and improves flexibility by separating parsing and
   376 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
   377 'fixes' etc.) are required in rare situations.
   378 
   379 * Syntax: constants introduced by new-style packages ('definition',
   380 'abbreviation' etc.) are passed through the syntax module in
   381 ``authentic mode''. This means that associated mixfix annotations
   382 really stick to such constants, independently of potential name space
   383 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   384 trees are represented slightly differently, may need to adapt syntax
   385 translations accordingly. Use CONST marker in 'translations' and
   386 @{const_syntax} antiquotation in 'parse_translation' etc.
   387 
   388 * Legacy goal package: reduced interface to the bare minimum required
   389 to keep existing proof scripts running.  Most other user-level
   390 functions are now part of the OldGoals structure, which is *not* open
   391 by default (consider isatool expandshort before open OldGoals).
   392 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   393 these tend to cause confusion about the actual goal (!) context being
   394 used here, which is not necessarily the same as the_context().
   395 
   396 * Command 'find_theorems': supports "*" wild-card in "name:"
   397 criterion; "with_dups" option.  Certain ProofGeneral versions might
   398 support a specific search form (see ProofGeneral/CHANGES).
   399 
   400 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   401 by default, which means that "prems" (and also "fixed variables") are
   402 suppressed from proof state output.  Note that the ProofGeneral
   403 settings mechanism allows to change and save options persistently, but
   404 older versions of Isabelle will fail to start up if a negative prems
   405 limit is imposed.
   406 
   407 * Local theory targets may be specified by non-nested blocks of
   408 ``context/locale/class ... begin'' followed by ``end''.  The body may
   409 contain definitions, theorems etc., including any derived mechanism
   410 that has been implemented on top of these primitives.  This concept
   411 generalizes the existing ``theorem (in ...)'' towards more versatility
   412 and scalability.
   413 
   414 * Proof General interface: proper undo of final 'end' command;
   415 discontinued Isabelle/classic mode (ML proof scripts).
   416 
   417 
   418 *** Document preparation ***
   419 
   420 * Added antiquotation @{theory name} which prints the given name,
   421 after checking that it refers to a valid ancestor theory in the
   422 current context.
   423 
   424 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   425 check the given source text as ML type/structure, printing verbatim.
   426 
   427 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   428 "c args == rhs" given in the current context.  (Any number of
   429 arguments may be given on the LHS.)
   430 
   431 
   432 *** Pure ***
   433 
   434 * The 'class' package offers a combination of axclass and locale to
   435 achieve Haskell-like type classes in Isabelle.  Definitions and
   436 theorems within a class context produce both relative results (with
   437 implicit parameters according to the locale context), and polymorphic
   438 constants with qualified polymorphism (according to the class
   439 context).  Within the body context of a 'class' target, a separate
   440 syntax layer ("user space type system") takes care of converting
   441 between global polymorphic consts and internal locale representation.
   442 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   443 "isatool doc classes" provides a tutorial.
   444 
   445 * Generic code generator framework allows to generate executable
   446 code for ML and Haskell (including Isabelle classes).  A short usage
   447 sketch:
   448 
   449     internal compilation:
   450         export_code <list of constants (term syntax)> in SML
   451     writing SML code to a file:
   452         export_code <list of constants (term syntax)> in SML <filename>
   453     writing OCaml code to a file:
   454         export_code <list of constants (term syntax)> in OCaml <filename>
   455     writing Haskell code to a bunch of files:
   456         export_code <list of constants (term syntax)> in Haskell <filename>
   457 
   458     evaluating closed propositions to True/False using code generation:
   459         method ``eval''
   460 
   461 Reasonable default setup of framework in HOL.
   462 
   463 Theorem attributs for selecting and transforming function equations theorems:
   464 
   465     [code fun]:        select a theorem as function equation for a specific constant
   466     [code fun del]:    deselect a theorem as function equation for a specific constant
   467     [code inline]:     select an equation theorem for unfolding (inlining) in place
   468     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   469 
   470 User-defined serializations (target in {SML, OCaml, Haskell}):
   471 
   472     code_const <and-list of constants (term syntax)>
   473       {(target) <and-list of const target syntax>}+
   474 
   475     code_type <and-list of type constructors>
   476       {(target) <and-list of type target syntax>}+
   477 
   478     code_instance <and-list of instances>
   479       {(target)}+
   480         where instance ::= <type constructor> :: <class>
   481 
   482     code_class <and_list of classes>
   483       {(target) <and-list of class target syntax>}+
   484         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   485 
   486 code_instance and code_class only are effective to target Haskell.
   487 
   488 For example usage see src/HOL/ex/Codegenerator.thy and
   489 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   490 generation from Isabelle/HOL theories is available via "isatool doc
   491 codegen".
   492 
   493 * Code generator: consts in 'consts_code' Isar commands are now
   494 referred to by usual term syntax (including optional type
   495 annotations).
   496 
   497 * Command 'no_translations' removes translation rules from theory
   498 syntax.
   499 
   500 * Overloaded definitions are now actually checked for acyclic
   501 dependencies.  The overloading scheme is slightly more general than
   502 that of Haskell98, although Isabelle does not demand an exact
   503 correspondence to type class and instance declarations.
   504 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   505 exotic versions of overloading -- at the discretion of the user!
   506 
   507 Polymorphic constants are represented via type arguments, i.e. the
   508 instantiation that matches an instance against the most general
   509 declaration given in the signature.  For example, with the declaration
   510 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   511 as c(nat).  Overloading is essentially simultaneous structural
   512 recursion over such type arguments.  Incomplete specification patterns
   513 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   514 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   515 Command 'print_theory' outputs the normalized system of recursive
   516 equations, see section "definitions".
   517 
   518 * Configuration options are maintained within the theory or proof
   519 context (with name and type bool/int/string), providing a very simple
   520 interface to a poor-man's version of general context data.  Tools may
   521 declare options in ML (e.g. using Attrib.config_int) and then refer to
   522 these values using Config.get etc.  Users may change options via an
   523 associated attribute of the same name.  This form of context
   524 declaration works particularly well with commands 'declare' or
   525 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   526 very easy to avoid global references, which would not observe Isar
   527 toplevel undo/redo and fail to work with multithreading.
   528 
   529 Various global ML references of Pure and HOL have been turned into
   530 configuration options:
   531 
   532   Unify.search_bound		unify_search_bound
   533   Unify.trace_bound		unify_trace_bound
   534   Unify.trace_simp		unify_trace_simp
   535   Unify.trace_types		unify_trace_types
   536   Simplifier.simp_depth_limit	simp_depth_limit
   537   Blast.depth_limit		blast_depth_limit
   538   DatatypeProp.dtK		datatype_distinctness_limit
   539   fast_arith_neq_limit  	fast_arith_neq_limit
   540   fast_arith_split_limit	fast_arith_split_limit
   541 
   542 * Named collections of theorems may be easily installed as context
   543 data using the functor NamedThmsFun (see also
   544 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   545 attributes; there is also a toplevel print command.  This facility is
   546 just a common case of general context data, which is the preferred way
   547 for anything more complex than just a list of facts in canonical
   548 order.
   549 
   550 * Isar: command 'declaration' augments a local theory by generic
   551 declaration functions written in ML.  This enables arbitrary content
   552 being added to the context, depending on a morphism that tells the
   553 difference of the original declaration context wrt. the application
   554 context encountered later on.
   555 
   556 * Isar: proper interfaces for simplification procedures.  Command
   557 'simproc_setup' declares named simprocs (with match patterns, and body
   558 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   559 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   560 
   561 * Isar: an extra pair of brackets around attribute declarations
   562 abbreviates a theorem reference involving an internal dummy fact,
   563 which will be ignored later --- only the effect of the attribute on
   564 the background context will persist.  This form of in-place
   565 declarations is particularly useful with commands like 'declare' and
   566 'using', for example ``have A using [[simproc a]] by simp''.
   567 
   568 * Isar: method "assumption" (and implicit closing of subproofs) now
   569 takes simple non-atomic goal assumptions into account: after applying
   570 an assumption as a rule the resulting subgoals are solved by atomic
   571 assumption steps.  This is particularly useful to finish 'obtain'
   572 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   573 without referring to the original premise "!!x. P x ==> thesis" in the
   574 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   575 more permissive.
   576 
   577 * Isar: implicit use of prems from the Isar proof context is
   578 considered a legacy feature.  Common applications like ``have A .''
   579 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   580 referencing facts explicitly here improves readability and
   581 maintainability of proof texts.
   582 
   583 * Isar: improper proof element 'guess' is like 'obtain', but derives
   584 the obtained context from the course of reasoning!  For example:
   585 
   586   assume "EX x y. A x & B y"   -- "any previous fact"
   587   then guess x and y by clarify
   588 
   589 This technique is potentially adventurous, depending on the facts and
   590 proof tools being involved here.
   591 
   592 * Isar: known facts from the proof context may be specified as literal
   593 propositions, using ASCII back-quote syntax.  This works wherever
   594 named facts used to be allowed so far, in proof commands, proof
   595 methods, attributes etc.  Literal facts are retrieved from the context
   596 according to unification of type and term parameters.  For example,
   597 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   598 theorems in the current context, then these are valid literal facts:
   599 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   600 
   601 There is also a proof method "fact" which does the same composition
   602 for explicit goal states, e.g. the following proof texts coincide with
   603 certain special cases of literal facts:
   604 
   605   have "A" by fact                 ==  note `A`
   606   have "A ==> B" by fact           ==  note `A ==> B`
   607   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   608   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   609 
   610 * Isar: ":" (colon) is no longer a symbolic identifier character in
   611 outer syntax.  Thus symbolic identifiers may be used without
   612 additional white space in declarations like this: ``assume *: A''.
   613 
   614 * Isar: 'print_facts' prints all local facts of the current context,
   615 both named and unnamed ones.
   616 
   617 * Isar: 'def' now admits simultaneous definitions, e.g.:
   618 
   619   def x == "t" and y == "u"
   620 
   621 * Isar: added command 'unfolding', which is structurally similar to
   622 'using', but affects both the goal state and facts by unfolding given
   623 rewrite rules.  Thus many occurrences of the 'unfold' method or
   624 'unfolded' attribute may be replaced by first-class proof text.
   625 
   626 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   627 and command 'unfolding' now all support object-level equalities
   628 (potentially conditional).  The underlying notion of rewrite rule is
   629 analogous to the 'rule_format' attribute, but *not* that of the
   630 Simplifier (which is usually more generous).
   631 
   632 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   633 premises of a theorem by n. Useful in conjunction with drule.
   634 
   635 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   636 method expression within a sandbox consisting of the first N
   637 sub-goals, which need to exist.  For example, ``simp_all [3]''
   638 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   639 simplifies all new goals that emerge from applying rule foo to the
   640 originally first one.
   641 
   642 * Isar: schematic goals are no longer restricted to higher-order
   643 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   644 expected.
   645 
   646 * Isar: the conclusion of a long theorem statement is now either
   647 'shows' (a simultaneous conjunction, as before), or 'obtains'
   648 (essentially a disjunction of cases with local parameters and
   649 assumptions).  The latter allows to express general elimination rules
   650 adequately; in this notation common elimination rules look like this:
   651 
   652   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   653     assumes "EX x. P x"
   654     obtains x where "P x"
   655 
   656   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   657     assumes "A & B"
   658     obtains A and B
   659 
   660   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   661     assumes "A | B"
   662     obtains
   663       A
   664     | B
   665 
   666 The subsequent classical rules even refer to the formal "thesis"
   667 explicitly:
   668 
   669   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   670     obtains "~ thesis"
   671 
   672   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   673     obtains "thesis ==> something"
   674 
   675 The actual proof of an 'obtains' statement is analogous to that of the
   676 Isar proof element 'obtain', only that there may be several cases.
   677 Optional case names may be specified in parentheses; these will be
   678 available both in the present proof and as annotations in the
   679 resulting rule, for later use with the 'cases' method (cf. attribute
   680 case_names).
   681 
   682 * Isar: the assumptions of a long theorem statement are available as
   683 "assms" fact in the proof context.  This is more appropriate than the
   684 (historical) "prems", which refers to all assumptions of the current
   685 context, including those from the target locale, proof body etc.
   686 
   687 * Isar: 'print_statement' prints theorems from the current theory or
   688 proof context in long statement form, according to the syntax of a
   689 top-level lemma.
   690 
   691 * Isar: 'obtain' takes an optional case name for the local context
   692 introduction rule (default "that").
   693 
   694 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   695 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   696 to occur.
   697 
   698 * Pure: syntax "CONST name" produces a fully internalized constant
   699 according to the current context.  This is particularly useful for
   700 syntax translations that should refer to internal constant
   701 representations independently of name spaces.
   702 
   703 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   704 instead of "FOO ". This allows multiple binder declarations to coexist
   705 in the same context.  INCOMPATIBILITY.
   706 
   707 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   708 primitive that also works in a locale context (both for constants and
   709 fixed variables). Type declaration and internal syntactic representation
   710 of given constants retrieved from the context. Likewise, the
   711 'no_notation' command allows to remove given syntax annotations from the
   712 current context.
   713 
   714 * Isar/locales: new derived specification elements 'axiomatization',
   715 'definition', 'abbreviation', which support type-inference, admit
   716 object-level specifications (equality, equivalence).  See also the
   717 isar-ref manual.  Examples:
   718 
   719   axiomatization
   720     eq  (infix "===" 50) where
   721     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   722 
   723   definition "f x y = x + y + 1"
   724   definition g where "g x = f x x"
   725 
   726   abbreviation
   727     neq  (infix "=!=" 50) where
   728     "x =!= y == ~ (x === y)"
   729 
   730 These specifications may be also used in a locale context.  Then the
   731 constants being introduced depend on certain fixed parameters, and the
   732 constant name is qualified by the locale base name.  An internal
   733 abbreviation takes care for convenient input and output, making the
   734 parameters implicit and using the original short name.  See also
   735 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   736 entities from a monomorphic theory.
   737 
   738 Presently, abbreviations are only available 'in' a target locale, but
   739 not inherited by general import expressions.  Also note that
   740 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   741 'translations' in common applications.  The "no_abbrevs" print mode
   742 prevents folding of abbreviations in term output.
   743 
   744 Concrete syntax is attached to specified constants in internal form,
   745 independently of name spaces.  The parse tree representation is
   746 slightly different -- use 'notation' instead of raw 'syntax', and
   747 'translations' with explicit "CONST" markup to accommodate this.
   748 
   749 * Pure/Isar: unified syntax for new-style specification mechanisms
   750 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   751 full type inference and dummy patterns ("_").  For example:
   752 
   753   definition "K x _ = x"
   754 
   755   inductive conj for A B
   756   where "A ==> B ==> conj A B"
   757 
   758 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   759 the current context.  Print mode "no_abbrevs" prevents inversion of
   760 abbreviations on output.
   761 
   762 * Isar/locales: improved parameter handling: use of locales "var" and
   763 "struct" no longer necessary; - parameter renamings are no longer
   764 required to be injective.  For example, this allows to define
   765 endomorphisms as locale endom = homom mult mult h.
   766 
   767 * Isar/locales: changed the way locales with predicates are defined.
   768 Instead of accumulating the specification, the imported expression is
   769 now an interpretation.  INCOMPATIBILITY: different normal form of
   770 locale expressions.  In particular, in interpretations of locales with
   771 predicates, goals repesenting already interpreted fragments are not
   772 removed automatically.  Use methods `intro_locales' and
   773 `unfold_locales'; see below.
   774 
   775 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   776 provide backward reasoning on locales predicates.  The methods are
   777 aware of interpretations and discharge corresponding goals.
   778 `intro_locales' is less aggressive then `unfold_locales' and does not
   779 unfold predicates to assumptions.
   780 
   781 * Isar/locales: the order in which locale fragments are accumulated
   782 has changed.  This enables to override declarations from fragments due
   783 to interpretations -- for example, unwanted simp rules.
   784 
   785 * Isar/locales: interpretation in theories and proof contexts has been
   786 extended.  One may now specify (and prove) equations, which are
   787 unfolded in interpreted theorems.  This is useful for replacing
   788 defined concepts (constants depending on locale parameters) by
   789 concepts already existing in the target context.  Example:
   790 
   791   interpretation partial_order ["op <= :: [int, int] => bool"]
   792     where "partial_order.less (op <=) (x::int) y = (x < y)"
   793 
   794 Typically, the constant `partial_order.less' is created by a
   795 definition specification element in the context of locale
   796 partial_order.
   797 
   798 * Method "induct": improved internal context management to support
   799 local fixes and defines on-the-fly. Thus explicit meta-level
   800 connectives !!  and ==> are rarely required anymore in inductive goals
   801 (using object-logic connectives for this purpose has been long
   802 obsolete anyway). Common proof patterns are explained in
   803 src/HOL/Induct/Common_Patterns.thy, see also
   804 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   805 examples.
   806 
   807 * Method "induct": improved handling of simultaneous goals. Instead of
   808 introducing object-level conjunction, the statement is now split into
   809 several conclusions, while the corresponding symbolic cases are nested
   810 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   811 see src/HOL/Induct/Common_Patterns.thy, for example.
   812 
   813 * Method "induct": mutual induction rules are now specified as a list
   814 of rule sharing the same induction cases. HOL packages usually provide
   815 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   816 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   817 mutual induction rules differently, i.e. like this:
   818 
   819   (induct rule: foo_bar.inducts)
   820   (induct set: foo bar)
   821   (induct pred: foo bar)
   822   (induct type: foo bar)
   823 
   824 The ML function ProjectRule.projections turns old-style rules into the
   825 new format.
   826 
   827 * Method "coinduct": dual of induction, see
   828 src/HOL/Library/Coinductive_List.thy for various examples.
   829 
   830 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   831 considered a legacy feature.
   832 
   833 * Attribute "symmetric" produces result with standardized schematic
   834 variables (index 0).  Potential INCOMPATIBILITY.
   835 
   836 * Simplifier: by default the simplifier trace only shows top level
   837 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   838 default. Thus there is less danger of being flooded by the trace. The
   839 trace indicates where parts have been suppressed.
   840   
   841 * Provers/classical: removed obsolete classical version of elim_format
   842 attribute; classical elim/dest rules are now treated uniformly when
   843 manipulating the claset.
   844 
   845 * Provers/classical: stricter checks to ensure that supplied intro,
   846 dest and elim rules are well-formed; dest and elim rules must have at
   847 least one premise.
   848 
   849 * Provers/classical: attributes dest/elim/intro take an optional
   850 weight argument for the rule (just as the Pure versions).  Weights are
   851 ignored by automated tools, but determine the search order of single
   852 rule steps.
   853 
   854 * Syntax: input syntax now supports dummy variable binding "%_. b",
   855 where the body does not mention the bound variable.  Note that dummy
   856 patterns implicitly depend on their context of bounds, which makes
   857 "{_. _}" match any set comprehension as expected.  Potential
   858 INCOMPATIBILITY -- parse translations need to cope with syntactic
   859 constant "_idtdummy" in the binding position.
   860 
   861 * Syntax: removed obsolete syntactic constant "_K" and its associated
   862 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   863 for example "A -> B" => "Pi A (%_. B)".
   864 
   865 * Pure: 'class_deps' command visualizes the subclass relation, using
   866 the graph browser tool.
   867 
   868 * Pure: 'print_theory' now suppresses certain internal declarations by
   869 default; use '!' option for full details.
   870 
   871 
   872 *** HOL ***
   873 
   874 * Method "metis" proves goals by applying the Metis general-purpose
   875 resolution prover (see also http://gilith.com/software/metis/).
   876 Examples are in the directory MetisExamples.  WARNING: the
   877 Isabelle/HOL-Metis integration does not yet work properly with
   878 multi-threading.
   879   
   880 * Command 'sledgehammer' invokes external automatic theorem provers as
   881 background processes.  It generates calls to the "metis" method if
   882 successful. These can be pasted into the proof.  Users do not have to
   883 wait for the automatic provers to return.  WARNING: does not really
   884 work with multi-threading.
   885 
   886 * New "auto_quickcheck" feature tests outermost goal statements for
   887 potential counter-examples.  Controlled by ML references
   888 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   889 5000 milliseconds).  Fails silently if statements is outside of
   890 executable fragment, or any other codgenerator problem occurs.
   891 
   892 * New constant "undefined" with axiom "undefined x = undefined".
   893 
   894 * Added class "HOL.eq", allowing for code generation with polymorphic
   895 equality.
   896 
   897 * Some renaming of class constants due to canonical name prefixing in
   898 the new 'class' package:
   899 
   900     HOL.abs ~> HOL.abs_class.abs
   901     HOL.divide ~> HOL.divide_class.divide
   902     0 ~> HOL.zero_class.zero
   903     1 ~> HOL.one_class.one
   904     op + ~> HOL.plus_class.plus
   905     op - ~> HOL.minus_class.minus
   906     uminus ~> HOL.minus_class.uminus
   907     op * ~> HOL.times_class.times
   908     op < ~> HOL.ord_class.less
   909     op <= > HOL.ord_class.less_eq
   910     Nat.power ~> Power.power_class.power
   911     Nat.size ~> Nat.size_class.size
   912     Numeral.number_of ~> Numeral.number_class.number_of
   913     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
   914     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
   915     Orderings.min ~> Orderings.ord_class.min
   916     Orderings.max ~> Orderings.ord_class.max
   917     Divides.op div ~> Divides.div_class.div
   918     Divides.op mod ~> Divides.div_class.mod
   919     Divides.op dvd ~> Divides.div_class.dvd
   920 
   921 INCOMPATIBILITY.  Adaptions may be required in the following cases:
   922 
   923 a) User-defined constants using any of the names "plus", "minus",
   924 "times", "less" or "less_eq". The standard syntax translations for
   925 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
   926 names.
   927 
   928 b) Variables named "plus", "minus", "times", "less", "less_eq"
   929 INCOMPATIBILITY: use more specific names.
   930 
   931 c) Permutative equations (e.g. "a + b = b + a")
   932 Since the change of names also changes the order of terms, permutative
   933 rewrite rules may get applied in a different order. Experience shows
   934 that this is rarely the case (only two adaptions in the whole Isabelle
   935 distribution).  INCOMPATIBILITY: rewrite proofs
   936 
   937 d) ML code directly refering to constant names
   938 This in general only affects hand-written proof tactics, simprocs and
   939 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
   940 Consider using @{const_name} antiquotation.
   941 
   942 * New class "default" with associated constant "default".
   943 
   944 * Function "sgn" is now overloaded and available on int, real, complex
   945 (and other numeric types), using class "sgn".  Two possible defs of
   946 sgn are given as equational assumptions in the classes sgn_if and
   947 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   948 INCOMPATIBILITY.
   949 
   950 * Locale "partial_order" now unified with class "order" (cf. theory
   951 Orderings), added parameter "less".  INCOMPATIBILITY.
   952 
   953 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
   954 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   955 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   956 
   957 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   958 changed order of proof goals in instance proofs.
   959 
   960 * The transitivity reasoner for partial and linear orders is set up
   961 for classes "order" and "linorder".  Instances of the reasoner are available
   962 in all contexts importing or interpreting the corresponding locales.
   963 Method "order" invokes the reasoner separately; the reasoner
   964 is also integrated with the Simplifier as a solver.  Diagnostic
   965 command 'print_orders' shows the available instances of the reasoner
   966 in the current context.
   967 
   968 * Localized monotonicity predicate in theory "Orderings"; integrated
   969 lemmas max_of_mono and min_of_mono with this predicate.
   970 INCOMPATIBILITY.
   971 
   972 * Formulation of theorem "dense" changed slightly due to integration
   973 with new class dense_linear_order.
   974 
   975 * Uniform lattice theory development in HOL.
   976 
   977     constants "meet" and "join" now named "inf" and "sup"
   978     constant "Meet" now named "Inf"
   979 
   980     classes "meet_semilorder" and "join_semilorder" now named
   981       "lower_semilattice" and "upper_semilattice"
   982     class "lorder" now named "lattice"
   983     class "comp_lat" now named "complete_lattice"
   984 
   985     Instantiation of lattice classes allows explicit definitions
   986     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
   987 
   988   INCOMPATIBILITY.  Theorem renames:
   989 
   990     meet_left_le            ~> inf_le1
   991     meet_right_le           ~> inf_le2
   992     join_left_le            ~> sup_ge1
   993     join_right_le           ~> sup_ge2
   994     meet_join_le            ~> inf_sup_ord
   995     le_meetI                ~> le_infI
   996     join_leI                ~> le_supI
   997     le_meet                 ~> le_inf_iff
   998     le_join                 ~> ge_sup_conv
   999     meet_idempotent         ~> inf_idem
  1000     join_idempotent         ~> sup_idem
  1001     meet_comm               ~> inf_commute
  1002     join_comm               ~> sup_commute
  1003     meet_leI1               ~> le_infI1
  1004     meet_leI2               ~> le_infI2
  1005     le_joinI1               ~> le_supI1
  1006     le_joinI2               ~> le_supI2
  1007     meet_assoc              ~> inf_assoc
  1008     join_assoc              ~> sup_assoc
  1009     meet_left_comm          ~> inf_left_commute
  1010     meet_left_idempotent    ~> inf_left_idem
  1011     join_left_comm          ~> sup_left_commute
  1012     join_left_idempotent    ~> sup_left_idem
  1013     meet_aci                ~> inf_aci
  1014     join_aci                ~> sup_aci
  1015     le_def_meet             ~> le_iff_inf
  1016     le_def_join             ~> le_iff_sup
  1017     join_absorp2            ~> sup_absorb2
  1018     join_absorp1            ~> sup_absorb1
  1019     meet_absorp1            ~> inf_absorb1
  1020     meet_absorp2            ~> inf_absorb2
  1021     meet_join_absorp        ~> inf_sup_absorb
  1022     join_meet_absorp        ~> sup_inf_absorb
  1023     distrib_join_le         ~> distrib_sup_le
  1024     distrib_meet_le         ~> distrib_inf_le
  1025 
  1026     add_meet_distrib_left   ~> add_inf_distrib_left
  1027     add_join_distrib_left   ~> add_sup_distrib_left
  1028     is_join_neg_meet        ~> is_join_neg_inf
  1029     is_meet_neg_join        ~> is_meet_neg_sup
  1030     add_meet_distrib_right  ~> add_inf_distrib_right
  1031     add_join_distrib_right  ~> add_sup_distrib_right
  1032     add_meet_join_distribs  ~> add_sup_inf_distribs
  1033     join_eq_neg_meet        ~> sup_eq_neg_inf
  1034     meet_eq_neg_join        ~> inf_eq_neg_sup
  1035     add_eq_meet_join        ~> add_eq_inf_sup
  1036     meet_0_imp_0            ~> inf_0_imp_0
  1037     join_0_imp_0            ~> sup_0_imp_0
  1038     meet_0_eq_0             ~> inf_0_eq_0
  1039     join_0_eq_0             ~> sup_0_eq_0
  1040     neg_meet_eq_join        ~> neg_inf_eq_sup
  1041     neg_join_eq_meet        ~> neg_sup_eq_inf
  1042     join_eq_if              ~> sup_eq_if
  1043 
  1044     mono_meet               ~> mono_inf
  1045     mono_join               ~> mono_sup
  1046     meet_bool_eq            ~> inf_bool_eq
  1047     join_bool_eq            ~> sup_bool_eq
  1048     meet_fun_eq             ~> inf_fun_eq
  1049     join_fun_eq             ~> sup_fun_eq
  1050     meet_set_eq             ~> inf_set_eq
  1051     join_set_eq             ~> sup_set_eq
  1052     meet1_iff               ~> inf1_iff
  1053     meet2_iff               ~> inf2_iff
  1054     meet1I                  ~> inf1I
  1055     meet2I                  ~> inf2I
  1056     meet1D1                 ~> inf1D1
  1057     meet2D1                 ~> inf2D1
  1058     meet1D2                 ~> inf1D2
  1059     meet2D2                 ~> inf2D2
  1060     meet1E                  ~> inf1E
  1061     meet2E                  ~> inf2E
  1062     join1_iff               ~> sup1_iff
  1063     join2_iff               ~> sup2_iff
  1064     join1I1                 ~> sup1I1
  1065     join2I1                 ~> sup2I1
  1066     join1I1                 ~> sup1I1
  1067     join2I2                 ~> sup1I2
  1068     join1CI                 ~> sup1CI
  1069     join2CI                 ~> sup2CI
  1070     join1E                  ~> sup1E
  1071     join2E                  ~> sup2E
  1072 
  1073     is_meet_Meet            ~> is_meet_Inf
  1074     Meet_bool_def           ~> Inf_bool_def
  1075     Meet_fun_def            ~> Inf_fun_def
  1076     Meet_greatest           ~> Inf_greatest
  1077     Meet_lower              ~> Inf_lower
  1078     Meet_set_def            ~> Inf_set_def
  1079 
  1080     Sup_def                 ~> Sup_Inf
  1081     Sup_bool_eq             ~> Sup_bool_def
  1082     Sup_fun_eq              ~> Sup_fun_def
  1083     Sup_set_eq              ~> Sup_set_def
  1084 
  1085     listsp_meetI            ~> listsp_infI
  1086     listsp_meet_eq          ~> listsp_inf_eq
  1087 
  1088     meet_min                ~> inf_min
  1089     join_max                ~> sup_max
  1090 
  1091 * Added syntactic class "size"; overloaded constant "size" now has
  1092 type "'a::size ==> bool"
  1093 
  1094 * Internal reorganisation of `size' of datatypes: size theorems
  1095 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1096 simplification rules by default!); theorems "prod.size" now named
  1097 "*.size".
  1098 
  1099 * Class "div" now inherits from class "times" rather than "type".
  1100 INCOMPATIBILITY.
  1101 
  1102 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1103 Linorder etc.  have disappeared; operations defined in terms of
  1104 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1105 
  1106 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1107 
  1108 * HOL-Word: New extensive library and type for generic, fixed size
  1109 machine words, with arithemtic, bit-wise, shifting and rotating
  1110 operations, reflection into int, nat, and bool lists, automation for
  1111 linear arithmetic (by automatic reflection into nat or int), including
  1112 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1113 arithmetic type classes, supporting automatic simplification of
  1114 numerals on all operations.
  1115 
  1116 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1117 
  1118 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1119 
  1120 * Code generator library theories:
  1121   - Code_Integer represents HOL integers by big integer literals in target
  1122     languages.
  1123   - Code_Char represents HOL characters by character literals in target
  1124     languages.
  1125   - Code_Char_chr like Code_Char, but also offers treatment of character
  1126     codes; includes Code_Integer.
  1127   - Executable_Set allows to generate code for finite sets using lists.
  1128   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1129     denominator).
  1130   - Executable_Real implements a subset of real numbers, namly those
  1131     representable by rational numbers.
  1132   - Efficient_Nat implements natural numbers by integers, which in general will
  1133     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1134     includes Code_Integer.
  1135   - Code_Index provides an additional datatype index which is mapped to
  1136     target-language built-in integers.
  1137   - Code_Message provides an additional datatype message_string which is isomorphic to
  1138     strings; messages are mapped to target-language strings.
  1139 
  1140 * New package for inductive predicates
  1141 
  1142   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1143 
  1144     inductive
  1145       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1146       for z_1 :: U_1 and ... and z_n :: U_m
  1147     where
  1148       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1149     | ...
  1150 
  1151   with full support for type-inference, rather than
  1152 
  1153     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1154 
  1155     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1156     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1157 
  1158     inductive "s z_1 ... z_m"
  1159     intros
  1160       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1161       ...
  1162 
  1163   For backward compatibility, there is a wrapper allowing inductive
  1164   sets to be defined with the new package via
  1165 
  1166     inductive_set
  1167       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1168       for z_1 :: U_1 and ... and z_n :: U_m
  1169     where
  1170       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1171     | ...
  1172 
  1173   or
  1174 
  1175     inductive_set
  1176       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1177       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1178       for z_1 :: U_1 and ... and z_n :: U_m
  1179     where
  1180       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1181     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1182     | ...
  1183 
  1184   if the additional syntax "p ..." is required.
  1185 
  1186   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1187   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1188 
  1189   INCOMPATIBILITIES:
  1190 
  1191   - Since declaration and definition of inductive sets or predicates
  1192     is no longer separated, abbreviations involving the newly
  1193     introduced sets or predicates must be specified together with the
  1194     introduction rules after the 'where' keyword (see above), rather
  1195     than before the actual inductive definition.
  1196 
  1197   - The variables in induction and elimination rules are now
  1198     quantified in the order of their occurrence in the introduction
  1199     rules, rather than in alphabetical order. Since this may break
  1200     some proofs, these proofs either have to be repaired, e.g. by
  1201     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1202     statements of the form
  1203 
  1204       case (rule_i a_i_1 ... a_i_{k_i})
  1205 
  1206     or the old order of quantification has to be restored by explicitly adding
  1207     meta-level quantifiers in the introduction rules, i.e.
  1208 
  1209       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1210 
  1211   - The format of the elimination rules is now
  1212 
  1213       p z_1 ... z_m x_1 ... x_n ==>
  1214         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1215         ==> ... ==> P
  1216 
  1217     for predicates and
  1218 
  1219       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1220         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1221         ==> ... ==> P
  1222 
  1223     for sets rather than
  1224 
  1225       x : s z_1 ... z_m ==>
  1226         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1227         ==> ... ==> P
  1228 
  1229     This may require terms in goals to be expanded to n-tuples
  1230     (e.g. using case_tac or simplification with the split_paired_all
  1231     rule) before the above elimination rule is applicable.
  1232 
  1233   - The elimination or case analysis rules for (mutually) inductive
  1234     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1235     list of rules "p_1_..._p_k.elims" is no longer available.
  1236 
  1237 * New package "function"/"fun" for general recursive functions,
  1238 supporting mutual and nested recursion, definitions in local contexts,
  1239 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1240 for small examples, and the separate tutorial on the function
  1241 package. The old recdef "package" is still available as before, but
  1242 users are encouraged to use the new package.
  1243 
  1244 * Method "lexicographic_order" automatically synthesizes termination
  1245 relations as lexicographic combinations of size measures. 
  1246 
  1247 * Case-expressions allow arbitrary constructor-patterns (including
  1248 "_") and take their order into account, like in functional
  1249 programming.  Internally, this is translated into nested
  1250 case-expressions; missing cases are added and mapped to the predefined
  1251 constant "undefined". In complicated cases printing may no longer show
  1252 the original input but the internal form. Lambda-abstractions allow
  1253 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1254 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1255 variable.
  1256 
  1257 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1258 is an abbreviation for "of_nat :: nat => int". The simplification
  1259 rules for "of_nat" have been changed to work like "int" did
  1260 previously.  Potential INCOMPATIBILITY:
  1261   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1262   - of_nat_diff and of_nat_mult are no longer default simp rules
  1263 
  1264 * Method "algebra" solves polynomial equations over (semi)rings using
  1265 Groebner bases. The (semi)ring structure is defined by locales and the
  1266 tool setup depends on that generic context. Installing the method for
  1267 a specific type involves instantiating the locale and possibly adding
  1268 declarations for computation on the coefficients.  The method is
  1269 already instantiated for natural numbers and for the axiomatic class
  1270 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1271 CALCULEMUS 2007 for the general principles underlying this
  1272 architecture of context-aware proof-tools.
  1273 
  1274 * Method "ferrack" implements quantifier elimination over
  1275 special-purpose dense linear orders using locales (analogous to
  1276 "algebra"). The method is already installed for class
  1277 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1278 rat, etc.
  1279 
  1280 * Former constant "List.op @" now named "List.append".  Use ML
  1281 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1282 circumvent possible incompatibilities when working on ML level.
  1283 
  1284 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1285 
  1286 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1287 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1288 
  1289 * New syntax for Haskell-like list comprehension (input only), eg.
  1290 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1291 
  1292 * The special syntax for function "filter" has changed from [x :
  1293 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1294 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1295 
  1296 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1297 defined on nat only, as an abbreviation for [a..<Suc b]
  1298 INCOMPATIBILITY.
  1299 
  1300 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1301 
  1302 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1303 
  1304 * New lemma collection field_simps (an extension of ring_simps) for
  1305 manipulating (in)equations involving division. Multiplies with all
  1306 denominators that can be proved to be non-zero (in equations) or
  1307 positive/negative (in inequations).
  1308 
  1309 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1310 have been improved and renamed to ring_simps, group_simps and
  1311 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1312 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1313 
  1314 * Theory Library/Commutative_Ring: switched from recdef to function
  1315 package; constants add, mul, pow now curried.  Infix syntax for
  1316 algebraic operations.
  1317 
  1318 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1319 INCOMPATIBILITY.
  1320 
  1321 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1322 INCOMPATIBILITY.
  1323 
  1324 * HOL/records: generalised field-update to take a function on the
  1325 field rather than the new value: r(|A := x|) is translated to A_update
  1326 (K x) r The K-combinator that is internally used is called K_record.
  1327 INCOMPATIBILITY: Usage of the plain update functions has to be
  1328 adapted.
  1329  
  1330 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1331 * x = 0, which are required for a semiring.  Richer structures do not
  1332 inherit from semiring_0 anymore, because this property is a theorem
  1333 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1334 there is more to prove, but this is mostly trivial.
  1335 
  1336 * Class "recpower" is generalized to arbitrary monoids, not just
  1337 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1338 commutativity or semiring properties additionally.
  1339 
  1340 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1341 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1342 better use 'abbreviation'.
  1343 
  1344 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1345 
  1346 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1347 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1348 significant changes for setting up numeral syntax for types:
  1349   - New constants Numeral.pred and Numeral.succ instead
  1350       of former Numeral.bin_pred and Numeral.bin_succ.
  1351   - Use integer operations instead of bin_add, bin_mult and so on.
  1352   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1353   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1354 
  1355 See src/HOL/Integ/IntArith.thy for an example setup.
  1356 
  1357 * Command 'normal_form' computes the normal form of a term that may
  1358 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1359 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1360 heavy-duty computations because the functions are compiled to ML
  1361 first.  Correspondingly, a method "normalization" is provided.  See
  1362 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1363 
  1364 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1365 25 like -->); output depends on the "iff" print_mode, the default is
  1366 "A = B" (with priority 50).
  1367 
  1368 * Relations less (<) and less_eq (<=) are also available on type bool.
  1369 Modified syntax to disallow nesting without explicit parentheses,
  1370 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1371 INCOMPATIBILITY.
  1372 
  1373 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1374 
  1375 * Relation composition operator "op O" now has precedence 75 and binds
  1376 stronger than union and intersection. INCOMPATIBILITY.
  1377 
  1378 * The old set interval syntax "{m..n(}" (and relatives) has been
  1379 removed.  Use "{m..<n}" (and relatives) instead.
  1380 
  1381 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1382 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1383 ``declare [[simproc del: neq]]''.
  1384 
  1385 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1386 True/False.
  1387 
  1388 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1389 
  1390 * Theorem setsum_mult renamed to setsum_right_distrib.
  1391 
  1392 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1393 ``rule'' method.
  1394 
  1395 * Reimplemented methods "sat" and "satx", with several improvements:
  1396 goals no longer need to be stated as "<prems> ==> False", equivalences
  1397 (i.e. "=" on type bool) are handled, variable names of the form
  1398 "lit_<n>" are no longer reserved, significant speedup.
  1399 
  1400 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1401 zChaff is still supported as well.
  1402 
  1403 * 'inductive' and 'datatype': provide projections of mutual rules,
  1404 bundled as foo_bar.inducts;
  1405 
  1406 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1407 Library.
  1408 
  1409 * Library: moved theory Accessible_Part to main HOL.
  1410 
  1411 * Library: added theory Coinductive_List of potentially infinite lists
  1412 as greatest fixed-point.
  1413 
  1414 * Library: added theory AssocList which implements (finite) maps as
  1415 association lists.
  1416 
  1417 * Method "evaluation" solves goals (i.e. a boolean expression)
  1418 efficiently by compiling it to ML.  The goal is "proved" (via an
  1419 oracle) if it evaluates to True.
  1420 
  1421 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1422 also when invoked by the simplifier.  This results in the Simplifier
  1423 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1424 Configuration option fast_arith_split_limit=0 recovers the old
  1425 behavior.
  1426 
  1427 * Support for hex (0x20) and binary (0b1001) numerals.
  1428 
  1429 * New method: reify eqs (t), where eqs are equations for an
  1430 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1431 parameter, computes a term s::'b and a list xs::'a list and proves the
  1432 theorem I xs s = t. This is also known as reification or quoting. The
  1433 resulting theorem is applied to the subgoal to substitute t with I xs
  1434 s.  If t is omitted, the subgoal itself is reified.
  1435 
  1436 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1437 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1438 where f is supposed to be a computable function (in the sense of code
  1439 generattion). The method uses reify to compute s and xs as above then
  1440 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1441 r and finally gets the theorem t = r, which is again applied to the
  1442 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1443 
  1444 * Reflection: Automatic reification now handels binding, an example is
  1445 available in src/HOL/ex/ReflectionEx.thy
  1446 
  1447 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1448 command 'statespace' that is similar to 'record', but introduces an
  1449 abstract specification based on the locale infrastructure instead of
  1450 HOL types.  This leads to extra flexibility in composing state spaces,
  1451 in particular multiple inheritance and renaming of components.
  1452 
  1453 
  1454 *** HOL-Complex ***
  1455 
  1456 * Hyperreal: Functions root and sqrt are now defined on negative real
  1457 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1458 Nonnegativity side conditions have been removed from many lemmas, so
  1459 that more subgoals may now be solved by simplification; potential
  1460 INCOMPATIBILITY.
  1461 
  1462 * Real: new type classes formalize real normed vector spaces and
  1463 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1464 and norm :: 'a => real.
  1465 
  1466 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1467 reals into other types. The overloaded constant Reals :: 'a set is now
  1468 defined as range of_real; potential INCOMPATIBILITY.
  1469 
  1470 * Real: proper support for ML code generation, including 'quickcheck'.
  1471 Reals are implemented as arbitrary precision rationals.
  1472 
  1473 * Hyperreal: Several constants that previously worked only for the
  1474 reals have been generalized, so they now work over arbitrary vector
  1475 spaces. Type annotations may need to be added in some cases; potential
  1476 INCOMPATIBILITY.
  1477 
  1478   Infinitesimal  :: ('a::real_normed_vector) star set
  1479   HFinite        :: ('a::real_normed_vector) star set
  1480   HInfinite      :: ('a::real_normed_vector) star set
  1481   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1482   monad          :: ('a::real_normed_vector) star => 'a star set
  1483   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1484   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1485   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1486   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1487   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1488   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1489   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1490   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1491   sgn            :: 'a::real_normed_vector => 'a
  1492   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1493 
  1494 * Complex: Some complex-specific constants are now abbreviations for
  1495 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1496 hnorm.  Other constants have been entirely removed in favor of the
  1497 polymorphic versions (INCOMPATIBILITY):
  1498 
  1499   approx        <-- capprox
  1500   HFinite       <-- CFinite
  1501   HInfinite     <-- CInfinite
  1502   Infinitesimal <-- CInfinitesimal
  1503   monad         <-- cmonad
  1504   galaxy        <-- cgalaxy
  1505   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1506   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1507   (ns)deriv     <-- (ns)cderiv
  1508 
  1509 
  1510 *** HOL-Algebra ***
  1511 
  1512 * Formalisation of ideals and the quotient construction over rings.
  1513 
  1514 * Order and lattice theory no longer based on records.
  1515 INCOMPATIBILITY.
  1516 
  1517 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1518 greatest_closed.  INCOMPATIBILITY.
  1519 
  1520 * Method algebra is now set up via an attribute.  For examples see
  1521 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1522 of algebraic structures.
  1523 
  1524 * Renamed theory CRing to Ring.
  1525 
  1526 
  1527 *** HOL-Nominal ***
  1528 
  1529 * Substantial, yet incomplete support for nominal datatypes (binding
  1530 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1531 src/HOL/Nominal/Examples.  Prospective users should consult
  1532 http://isabelle.in.tum.de/nominal/
  1533 
  1534 
  1535 *** ML ***
  1536 
  1537 * ML basics: just one true type int, which coincides with IntInf.int
  1538 (even on SML/NJ).
  1539 
  1540 * ML within Isar: antiquotations allow to embed statically-checked
  1541 formal entities in the source, referring to the context available at
  1542 compile-time.  For example:
  1543 
  1544 ML {* @{sort "{zero,one}"} *}
  1545 ML {* @{typ "'a => 'b"} *}
  1546 ML {* @{term "%x. x"} *}
  1547 ML {* @{prop "x == y"} *}
  1548 ML {* @{ctyp "'a => 'b"} *}
  1549 ML {* @{cterm "%x. x"} *}
  1550 ML {* @{cprop "x == y"} *}
  1551 ML {* @{thm asm_rl} *}
  1552 ML {* @{thms asm_rl} *}
  1553 ML {* @{type_name c} *}
  1554 ML {* @{type_syntax c} *}
  1555 ML {* @{const_name c} *}
  1556 ML {* @{const_syntax c} *}
  1557 ML {* @{context} *}
  1558 ML {* @{theory} *}
  1559 ML {* @{theory Pure} *}
  1560 ML {* @{theory_ref} *}
  1561 ML {* @{theory_ref Pure} *}
  1562 ML {* @{simpset} *}
  1563 ML {* @{claset} *}
  1564 ML {* @{clasimpset} *}
  1565 
  1566 The same works for sources being ``used'' within an Isar context.
  1567 
  1568 * ML in Isar: improved error reporting; extra verbosity with
  1569 ML_Context.trace enabled.
  1570 
  1571 * Pure/General/table.ML: the join operations now works via exceptions
  1572 DUP/SAME instead of type option. This is simpler in simple cases, and
  1573 admits slightly more efficient complex applications.
  1574 
  1575 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1576 use Context.generic instead of just theory.
  1577 
  1578 * Pure: datatype Context.generic joins theory/Proof.context and
  1579 provides some facilities for code that works in either kind of
  1580 context, notably GenericDataFun for uniform theory and proof data.
  1581 
  1582 * Pure: simplified internal attribute type, which is now always
  1583 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1584 local (Proof.context) attributes have been discontinued, while
  1585 minimizing code duplication. Thm.rule_attribute and
  1586 Thm.declaration_attribute build canonical attributes; see also structure
  1587 Context for further operations on Context.generic, notably
  1588 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1589 declarations and definitions.
  1590 
  1591 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1592 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1593 init only required for impure data. INCOMPATIBILITY: empty really need
  1594 to be empty (no dependencies on theory content!)
  1595 
  1596 * Pure/kernel: consts certification ignores sort constraints given in
  1597 signature declarations. (This information is not relevant to the
  1598 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1599 potential INCOMPATIBILITY.
  1600 
  1601 * Pure: axiomatic type classes are now purely definitional, with
  1602 explicit proofs of class axioms and super class relations performed
  1603 internally. See Pure/axclass.ML for the main internal interfaces --
  1604 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1605 AxClass.axiomatize_class/classrel/arity supersede
  1606 Sign.add_classes/classrel/arities.
  1607 
  1608 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1609 global/local versions on theory vs. Proof.context have been
  1610 discontinued; Attrib.syntax and Method.syntax have been adapted
  1611 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1612 attributes, methods, etc.
  1613 
  1614 * Pure: several functions of signature "... -> theory -> theory * ..."
  1615 have been reoriented to "... -> theory -> ... * theory" in order to
  1616 allow natural usage in combination with the ||>, ||>>, |-> and
  1617 fold_map combinators.
  1618 
  1619 * Pure: official theorem names (closed derivations) and additional
  1620 comments (tags) are now strictly separate.  Name hints -- which are
  1621 maintained as tags -- may be attached any time without affecting the
  1622 derivation.
  1623 
  1624 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1625 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1626 achieve the old behaviour.
  1627 
  1628 * Pure: the "Goal" constant is now called "prop", supporting a
  1629 slightly more general idea of ``protecting'' meta-level rule
  1630 statements.
  1631 
  1632 * Pure: Logic.(un)varify only works in a global context, which is now
  1633 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1634 Logic.legacy_(un)varify as temporary workaround.
  1635 
  1636 * Pure: structure Name provides scalable operations for generating
  1637 internal variable names, notably Name.variants etc.  This replaces
  1638 some popular functions from term.ML:
  1639 
  1640   Term.variant		->  Name.variant
  1641   Term.variantlist	->  Name.variant_list
  1642   Term.invent_names	->  Name.invent_list
  1643 
  1644 Note that low-level renaming rarely occurs in new code -- operations
  1645 from structure Variable are used instead (see below).
  1646 
  1647 * Pure: structure Variable provides fundamental operations for proper
  1648 treatment of fixed/schematic variables in a context.  For example,
  1649 Variable.import introduces fixes for schematics of given facts and
  1650 Variable.export reverses the effect (up to renaming) -- this replaces
  1651 various freeze_thaw operations.
  1652 
  1653 * Pure: structure Goal provides simple interfaces for
  1654 init/conclude/finish and tactical prove operations (replacing former
  1655 Tactic.prove).  Goal.prove is the canonical way to prove results
  1656 within a given context; Goal.prove_global is a degraded version for
  1657 theory level goals, including a global Drule.standard.  Note that
  1658 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1659 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1660 in a locale context).
  1661 
  1662 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1663 and type checking (Syntax.check_term etc.), with common combinations
  1664 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1665 which are considered legacy and await removal.
  1666 
  1667 * Pure/Syntax: generic interfaces for type unchecking
  1668 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1669 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1670 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1671 available for convenience, but refer to the very same operations using
  1672 a mere theory instead of a full context.
  1673 
  1674 * Isar: simplified treatment of user-level errors, using exception
  1675 ERROR of string uniformly.  Function error now merely raises ERROR,
  1676 without any side effect on output channels.  The Isar toplevel takes
  1677 care of proper display of ERROR exceptions.  ML code may use plain
  1678 handle/can/try; cat_error may be used to concatenate errors like this:
  1679 
  1680   ... handle ERROR msg => cat_error msg "..."
  1681 
  1682 Toplevel ML code (run directly or through the Isar toplevel) may be
  1683 embedded into the Isar toplevel with exception display/debug like
  1684 this:
  1685 
  1686   Isar.toplevel (fn () => ...)
  1687 
  1688 INCOMPATIBILITY, removed special transform_error facilities, removed
  1689 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1690 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1691 -- use plain ERROR instead.
  1692 
  1693 * Isar: theory setup now has type (theory -> theory), instead of a
  1694 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1695 
  1696 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1697 ProofContext.debug/verbose flags.
  1698 
  1699 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1700 theory before entering a proof state.  Transactions now always see a
  1701 quasi-functional intermediate checkpoint, both in interactive and
  1702 batch mode.
  1703 
  1704 * Isar: simplified interfaces for outer syntax.  Renamed
  1705 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1706 OuterSyntax.add_parsers -- this functionality is now included in
  1707 OuterSyntax.command etc.  INCOMPATIBILITY.
  1708 
  1709 * Simplifier: the simpset of a running simplification process now
  1710 contains a proof context (cf. Simplifier.the_context), which is the
  1711 very context that the initial simpset has been retrieved from (by
  1712 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1713 (solver, looper etc.) may depend on arbitrary proof data.
  1714 
  1715 * Simplifier.inherit_context inherits the proof context (plus the
  1716 local bounds) of the current simplification process; any simproc
  1717 etc. that calls the Simplifier recursively should do this!  Removed
  1718 former Simplifier.inherit_bounds, which is already included here --
  1719 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1720 specify an explicit context using Simplifier.context/theory_context.
  1721 
  1722 * Simplifier/Classical Reasoner: more abstract interfaces
  1723 change_simpset/claset for modifying the simpset/claset reference of a
  1724 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1725 INCOMPATIBILITY.
  1726 
  1727 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1728 "Trueprop" etc.
  1729 
  1730 
  1731 *** System ***
  1732 
  1733 * settings: the default heap location within ISABELLE_HOME_USER now
  1734 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  1735 Isabelle installations.
  1736 
  1737 * isabelle-process: option -S (secure mode) disables some critical
  1738 operations, notably runtime compilation and evaluation of ML source
  1739 code.
  1740 
  1741 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1742 
  1743 * Support for parallel execution, using native multicore support of
  1744 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1745 independent theories, according to the given theory header
  1746 specifications. The maximum number of worker threads is specified via
  1747 usedir option -M or the "max-threads" setting in Proof General. A
  1748 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1749 to 6 on a 8-core machine.  User-code needs to observe certain
  1750 guidelines for thread-safe programming, see appendix A in the Isar
  1751 Implementation manual.
  1752 
  1753 
  1754 
  1755 New in Isabelle2005 (October 2005)
  1756 ----------------------------------
  1757 
  1758 *** General ***
  1759 
  1760 * Theory headers: the new header syntax for Isar theories is
  1761 
  1762   theory <name>
  1763   imports <theory1> ... <theoryN>
  1764   uses <file1> ... <fileM>
  1765   begin
  1766 
  1767 where the 'uses' part is optional.  The previous syntax
  1768 
  1769   theory <name> = <theory1> + ... + <theoryN>:
  1770 
  1771 will disappear in the next release.  Use isatool fixheaders to convert
  1772 existing theory files.  Note that there is no change in ancient
  1773 non-Isar theories now, but these will disappear soon.
  1774 
  1775 * Theory loader: parent theories can now also be referred to via
  1776 relative and absolute paths.
  1777 
  1778 * Command 'find_theorems' searches for a list of criteria instead of a
  1779 list of constants. Known criteria are: intro, elim, dest, name:string,
  1780 simp:term, and any term. Criteria can be preceded by '-' to select
  1781 theorems that do not match. Intro, elim, dest select theorems that
  1782 match the current goal, name:s selects theorems whose fully qualified
  1783 name contain s, and simp:term selects all simplification rules whose
  1784 lhs match term.  Any other term is interpreted as pattern and selects
  1785 all theorems matching the pattern. Available in ProofGeneral under
  1786 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1787 
  1788   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1789 
  1790 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1791 matching the current goal as introduction rule and not having "HOL."
  1792 in their name (i.e. not being defined in theory HOL).
  1793 
  1794 * Command 'thms_containing' has been discontinued in favour of
  1795 'find_theorems'; INCOMPATIBILITY.
  1796 
  1797 * Communication with Proof General is now 8bit clean, which means that
  1798 Unicode text in UTF-8 encoding may be used within theory texts (both
  1799 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1800 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1801 
  1802   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1803   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1804 
  1805 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1806 Classical Reasoner.  Typical big applications run around 2 times
  1807 faster.
  1808 
  1809 
  1810 *** Document preparation ***
  1811 
  1812 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1813 of raw sources.  Only those symbols that do not require additional
  1814 LaTeX packages (depending on comments in isabellesym.sty) are
  1815 displayed properly, everything else is left verbatim.  isatool display
  1816 and isatool print are used as front ends (these are subject to the
  1817 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1818 
  1819 * Command tags control specific markup of certain regions of text,
  1820 notably folding and hiding.  Predefined tags include "theory" (for
  1821 theory begin and end), "proof" for proof commands, and "ML" for
  1822 commands involving ML code; the additional tags "visible" and
  1823 "invisible" are unused by default.  Users may give explicit tag
  1824 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1825 interpretation of tags is determined by the LaTeX job during document
  1826 preparation: see option -V of isatool usedir, or options -n and -t of
  1827 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1828 \isadroptag.
  1829 
  1830 Several document versions may be produced at the same time via isatool
  1831 usedir (the generated index.html will link all of them).  Typical
  1832 specifications include ''-V document=theory,proof,ML'' to present
  1833 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1834 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1835 these parts without any formal replacement text.  The Isabelle site
  1836 default settings produce ''document'' and ''outline'' versions as
  1837 specified above.
  1838 
  1839 * Several new antiquotations:
  1840 
  1841   @{term_type term} prints a term with its type annotated;
  1842 
  1843   @{typeof term} prints the type of a term;
  1844 
  1845   @{const const} is the same as @{term const}, but checks that the
  1846   argument is a known logical constant;
  1847 
  1848   @{term_style style term} and @{thm_style style thm} print a term or
  1849   theorem applying a "style" to it
  1850 
  1851   @{ML text}
  1852 
  1853 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1854 definitions, equations, inequations etc., 'concl' printing only the
  1855 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1856 to print the specified premise.  TermStyle.add_style provides an ML
  1857 interface for introducing further styles.  See also the "LaTeX Sugar"
  1858 document practical applications.  The ML antiquotation prints
  1859 type-checked ML expressions verbatim.
  1860 
  1861 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1862 and 'text' support optional locale specification '(in loc)', which
  1863 specifies the default context for interpreting antiquotations.  For
  1864 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1865 
  1866 * Option 'locale=NAME' of antiquotations specifies an alternative
  1867 context interpreting the subsequent argument.  For example: @{thm
  1868 [locale=lattice] inf_assoc}.
  1869 
  1870 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1871 a proof context.
  1872 
  1873 * Proper output of antiquotations for theory commands involving a
  1874 proof context (such as 'locale' or 'theorem (in loc) ...').
  1875 
  1876 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1877 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1878 
  1879 * isatool usedir: new option -C (default true) controls whether option
  1880 -D should include a copy of the original document directory; -C false
  1881 prevents unwanted effects such as copying of administrative CVS data.
  1882 
  1883 
  1884 *** Pure ***
  1885 
  1886 * Considerably improved version of 'constdefs' command.  Now performs
  1887 automatic type-inference of declared constants; additional support for
  1888 local structure declarations (cf. locales and HOL records), see also
  1889 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1890 sequential dependencies of definitions within a single 'constdefs'
  1891 section; moreover, the declared name needs to be an identifier.  If
  1892 all fails, consider to fall back on 'consts' and 'defs' separately.
  1893 
  1894 * Improved indexed syntax and implicit structures.  First of all,
  1895 indexed syntax provides a notational device for subscripted
  1896 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1897 expressions.  Secondly, in a local context with structure
  1898 declarations, number indexes \<^sub>n or the empty index (default
  1899 number 1) refer to a certain fixed variable implicitly; option
  1900 show_structs controls printing of implicit structures.  Typical
  1901 applications of these concepts involve record types and locales.
  1902 
  1903 * New command 'no_syntax' removes grammar declarations (and
  1904 translations) resulting from the given syntax specification, which is
  1905 interpreted in the same manner as for the 'syntax' command.
  1906 
  1907 * 'Advanced' translation functions (parse_translation etc.) may depend
  1908 on the signature of the theory context being presently used for
  1909 parsing/printing, see also isar-ref manual.
  1910 
  1911 * Improved 'oracle' command provides a type-safe interface to turn an
  1912 ML expression of type theory -> T -> term into a primitive rule of
  1913 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1914 is already included here); see also FOL/ex/IffExample.thy;
  1915 INCOMPATIBILITY.
  1916 
  1917 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1918 before); "cI" is no longer bound, use "c.intro" instead.
  1919 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1920 axclasses vs. locales.
  1921 
  1922 * Improved internal renaming of symbolic identifiers -- attach primes
  1923 instead of base 26 numbers.
  1924 
  1925 * New flag show_question_marks controls printing of leading question
  1926 marks in schematic variable names.
  1927 
  1928 * In schematic variable names, *any* symbol following \<^isub> or
  1929 \<^isup> is now treated as part of the base name.  For example, the
  1930 following works without printing of awkward ".0" indexes:
  1931 
  1932   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1933     by simp
  1934 
  1935 * Inner syntax includes (*(*nested*) comments*).
  1936 
  1937 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1938 annotations as "(00...)".
  1939 
  1940 * Clear separation of logical types and nonterminals, where the latter
  1941 may only occur in 'syntax' specifications or type abbreviations.
  1942 Before that distinction was only partially implemented via type class
  1943 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1944 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1945 exotic syntax specifications may require further adaption
  1946 (e.g. Cube/Cube.thy).
  1947 
  1948 * Removed obsolete type class "logic", use the top sort {} instead.
  1949 Note that non-logical types should be declared as 'nonterminals'
  1950 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1951 specifications.
  1952 
  1953 * Attributes 'induct' and 'cases': type or set names may now be
  1954 locally fixed variables as well.
  1955 
  1956 * Simplifier: can now control the depth to which conditional rewriting
  1957 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1958 Limit.
  1959 
  1960 * Simplifier: simplification procedures may now take the current
  1961 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1962 interface), which is very useful for calling the Simplifier
  1963 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1964 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1965 low-level mk_simproc no longer applies Logic.varify internally, to
  1966 allow for use in a context of fixed variables.
  1967 
  1968 * thin_tac now works even if the assumption being deleted contains !!
  1969 or ==>.  More generally, erule now works even if the major premise of
  1970 the elimination rule contains !! or ==>.
  1971 
  1972 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1973 
  1974 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1975 from Pure, which contains all common declarations already.  Both
  1976 theories are defined via plain Isabelle/Isar .thy files.
  1977 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1978 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1979 use isatool fixcpure to adapt your theory and ML sources.
  1980 
  1981 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1982 selections of theorems in named facts via index ranges.
  1983 
  1984 * 'print_theorems': in theory mode, really print the difference
  1985 wrt. the last state (works for interactive theory development only),
  1986 in proof mode print all local facts (cf. 'print_facts');
  1987 
  1988 * 'hide': option '(open)' hides only base names.
  1989 
  1990 * More efficient treatment of intermediate checkpoints in interactive
  1991 theory development.
  1992 
  1993 * Code generator is now invoked via code_module (incremental code
  1994 generation) and code_library (modular code generation, ML structures
  1995 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1996 must be quoted when used as identifiers.
  1997 
  1998 * New 'value' command for reading, evaluating and printing terms using
  1999 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2000 quoted when used as identifier.
  2001 
  2002 
  2003 *** Locales ***
  2004 
  2005 * New commands for the interpretation of locale expressions in
  2006 theories (1), locales (2) and proof contexts (3).  These generate
  2007 proof obligations from the expression specification.  After the
  2008 obligations have been discharged, theorems of the expression are added
  2009 to the theory, target locale or proof context.  The synopsis of the
  2010 commands is a follows:
  2011 
  2012   (1) interpretation expr inst
  2013   (2) interpretation target < expr
  2014   (3) interpret expr inst
  2015 
  2016 Interpretation in theories and proof contexts require a parameter
  2017 instantiation of terms from the current context.  This is applied to
  2018 specifications and theorems of the interpreted expression.
  2019 Interpretation in locales only permits parameter renaming through the
  2020 locale expression.  Interpretation is smart in that interpretations
  2021 that are active already do not occur in proof obligations, neither are
  2022 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2023 inspect active interpretations of a particular locale.  For details,
  2024 see the Isar Reference manual.  Examples can be found in
  2025 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2026 
  2027 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2028 'interpret' instead.
  2029 
  2030 * New context element 'constrains' for adding type constraints to
  2031 parameters.
  2032 
  2033 * Context expressions: renaming of parameters with syntax
  2034 redeclaration.
  2035 
  2036 * Locale declaration: 'includes' disallowed.
  2037 
  2038 * Proper static binding of attribute syntax -- i.e. types / terms /
  2039 facts mentioned as arguments are always those of the locale definition
  2040 context, independently of the context of later invocations.  Moreover,
  2041 locale operations (renaming and type / term instantiation) are applied
  2042 to attribute arguments as expected.
  2043 
  2044 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2045 actual attributes; rare situations may require Attrib.attribute to
  2046 embed those attributes into Attrib.src that lack concrete syntax.
  2047 Attribute implementations need to cooperate properly with the static
  2048 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2049 Attrib.XXX_thm etc. already do the right thing without further
  2050 intervention.  Only unusual applications -- such as "where" or "of"
  2051 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2052 on the context and the facts involved -- may have to assign parsed
  2053 values to argument tokens explicitly.
  2054 
  2055 * Changed parameter management in theorem generation for long goal
  2056 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2057 theorem statement in rare situations.
  2058 
  2059 * Locale inspection command 'print_locale' omits notes elements.  Use
  2060 'print_locale!' to have them included in the output.
  2061 
  2062 
  2063 *** Provers ***
  2064 
  2065 * Provers/hypsubst.ML: improved version of the subst method, for
  2066 single-step rewriting: it now works in bound variable contexts. New is
  2067 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2068 rewrite a different subterm than the original subst method, which is
  2069 still available as 'simplesubst'.
  2070 
  2071 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2072 and quasi orders.
  2073 
  2074 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2075 reflexive-transitive closure of relations.
  2076 
  2077 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2078 limit (previously hard-coded with a value of 20) user-definable.
  2079 
  2080 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2081 is peformed already.  Object-logics merely need to finish their
  2082 initial simpset configuration as before.  INCOMPATIBILITY.
  2083 
  2084 
  2085 *** HOL ***
  2086 
  2087 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2088 
  2089   syntax (epsilon)
  2090     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2091 
  2092 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2093 and x-symbol; use option '-m epsilon' to get it actually printed.
  2094 Moreover, the mathematically important symbolic identifier \<epsilon>
  2095 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2096 
  2097 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2098 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2099 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2100 support corresponding Isar calculations.
  2101 
  2102 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2103 instead of ":".
  2104 
  2105 * theory SetInterval: changed the syntax for open intervals:
  2106 
  2107   Old       New
  2108   {..n(}    {..<n}
  2109   {)n..}    {n<..}
  2110   {m..n(}   {m..<n}
  2111   {)m..n}   {m<..n}
  2112   {)m..n(}  {m<..<n}
  2113 
  2114 The old syntax is still supported but will disappear in the next
  2115 release.  For conversion use the following Emacs search and replace
  2116 patterns (these are not perfect but work quite well):
  2117 
  2118   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2119   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2120 
  2121 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2122 equalities in commutative rings; method 'algebra' provides a generic
  2123 interface.
  2124 
  2125 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2126 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2127 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2128 be a tuple pattern.
  2129 
  2130 Some new syntax forms are available:
  2131 
  2132   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2133   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2134   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2135   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2136 
  2137 The latter form "\<Sum>x < k. e" used to be based on a separate
  2138 function "Summation", which has been discontinued.
  2139 
  2140 * theory Finite_Set: in structured induction proofs, the insert case
  2141 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2142 (insert F x)'.
  2143 
  2144 * The 'refute' command has been extended to support a much larger
  2145 fragment of HOL, including axiomatic type classes, constdefs and
  2146 typedefs, inductive datatypes and recursion.
  2147 
  2148 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2149 Requires zChaff with proof generation to be installed.  See
  2150 HOL/ex/SAT_Examples.thy for examples.
  2151 
  2152 * Datatype induction via method 'induct' now preserves the name of the
  2153 induction variable. For example, when proving P(xs::'a list) by
  2154 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2155 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2156 in unstructured proof scripts.
  2157 
  2158 * Reworked implementation of records.  Improved scalability for
  2159 records with many fields, avoiding performance problems for type
  2160 inference. Records are no longer composed of nested field types, but
  2161 of nested extension types. Therefore the record type only grows linear
  2162 in the number of extensions and not in the number of fields.  The
  2163 top-level (users) view on records is preserved.  Potential
  2164 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2165 old record representation. The type generated for a record is called
  2166 <record_name>_ext_type.
  2167 
  2168 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2169 proofs triggered by a record definition or a simproc (if
  2170 quick_and_dirty is enabled).  Definitions of large records can take
  2171 quite long.
  2172 
  2173 New simproc record_upd_simproc for simplification of multiple record
  2174 updates enabled by default.  Moreover, trivial updates are also
  2175 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2176 occasionally, since simplification is more powerful by default.
  2177 
  2178 * typedef: proper support for polymorphic sets, which contain extra
  2179 type-variables in the term.
  2180 
  2181 * Simplifier: automatically reasons about transitivity chains
  2182 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2183 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2184 old proofs break occasionally as simplification may now solve more
  2185 goals than previously.
  2186 
  2187 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2188 present.  Works for all partial orders (class "order"), in particular
  2189 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2190 just like y <= x.
  2191 
  2192 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2193 bound variable or a constant then the let is unfolded.  Otherwise
  2194 first a is simplified to b, and then f b is simplified to g. If
  2195 possible we abstract b from g arriving at "let x = b in h x",
  2196 otherwise we unfold the let and arrive at g.  The simproc can be
  2197 enabled/disabled by the reference use_let_simproc.  Potential
  2198 INCOMPATIBILITY since simplification is more powerful by default.
  2199 
  2200 * Classical reasoning: the meson method now accepts theorems as arguments.
  2201 
  2202 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2203 jobs to provide advice on the provability of subgoals.
  2204 
  2205 * Theory OrderedGroup and Ring_and_Field: various additions and
  2206 improvements to faciliate calculations involving equalities and
  2207 inequalities.
  2208 
  2209 The following theorems have been eliminated or modified
  2210 (INCOMPATIBILITY):
  2211 
  2212   abs_eq             now named abs_of_nonneg
  2213   abs_of_ge_0        now named abs_of_nonneg
  2214   abs_minus_eq       now named abs_of_nonpos
  2215   imp_abs_id         now named abs_of_nonneg
  2216   imp_abs_neg_id     now named abs_of_nonpos
  2217   mult_pos           now named mult_pos_pos
  2218   mult_pos_le        now named mult_nonneg_nonneg
  2219   mult_pos_neg_le    now named mult_nonneg_nonpos
  2220   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2221   mult_neg           now named mult_neg_neg
  2222   mult_neg_le        now named mult_nonpos_nonpos
  2223 
  2224 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2225      
  2226      zero_le_square
  2227      not_square_less_zero 
  2228 
  2229   The following lemmas have been deleted from Real/RealPow:
  2230   
  2231      realpow_zero_zero
  2232      realpow_two
  2233      realpow_less
  2234      zero_le_power
  2235      realpow_two_le
  2236      abs_realpow_two
  2237      realpow_two_abs     
  2238 
  2239 * Theory Parity: added rules for simplifying exponents.
  2240 
  2241 * Theory List:
  2242 
  2243 The following theorems have been eliminated or modified
  2244 (INCOMPATIBILITY):
  2245 
  2246   list_all_Nil       now named list_all.simps(1)
  2247   list_all_Cons      now named list_all.simps(2)
  2248   list_all_conv      now named list_all_iff
  2249   set_mem_eq         now named mem_iff
  2250 
  2251 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2252 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2253 
  2254 
  2255 *** HOL-Complex ***
  2256 
  2257 * Theory RealDef: better support for embedding natural numbers and
  2258 integers in the reals.
  2259 
  2260 The following theorems have been eliminated or modified
  2261 (INCOMPATIBILITY):
  2262 
  2263   exp_ge_add_one_self  now requires no hypotheses
  2264   real_of_int_add      reversed direction of equality (use [symmetric])
  2265   real_of_int_minus    reversed direction of equality (use [symmetric])
  2266   real_of_int_diff     reversed direction of equality (use [symmetric])
  2267   real_of_int_mult     reversed direction of equality (use [symmetric])
  2268 
  2269 * Theory RComplete: expanded support for floor and ceiling functions.
  2270 
  2271 * Theory Ln is new, with properties of the natural logarithm
  2272 
  2273 * Hyperreal: There is a new type constructor "star" for making
  2274 nonstandard types.  The old type names are now type synonyms:
  2275 
  2276   hypreal = real star
  2277   hypnat = nat star
  2278   hcomplex = complex star
  2279 
  2280 * Hyperreal: Many groups of similarly-defined constants have been
  2281 replaced by polymorphic versions (INCOMPATIBILITY):
  2282 
  2283   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2284 
  2285   starset      <-- starsetNat, starsetC
  2286   *s*          <-- *sNat*, *sc*
  2287   starset_n    <-- starsetNat_n, starsetC_n
  2288   *sn*         <-- *sNatn*, *scn*
  2289   InternalSets <-- InternalNatSets, InternalCSets
  2290 
  2291   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2292   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2293   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2294   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2295   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2296 
  2297 * Hyperreal: Many type-specific theorems have been removed in favor of
  2298 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2299 
  2300   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2301   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2302   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2303   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2304   right_minus <-- hypreal_add_minus
  2305   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2306   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2307   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2308   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2309   mult_1_right <-- hcomplex_mult_one_right
  2310   mult_zero_left <-- hcomplex_mult_zero_left
  2311   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2312   right_distrib <-- hypnat_add_mult_distrib2
  2313   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2314   right_inverse <-- hypreal_mult_inverse
  2315   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2316   order_refl <-- {hypreal,hypnat}_le_refl
  2317   order_trans <-- {hypreal,hypnat}_le_trans
  2318   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2319   order_less_le <-- {hypreal,hypnat}_less_le
  2320   linorder_linear <-- {hypreal,hypnat}_le_linear
  2321   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2322   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2323   add_nonneg_nonneg <-- hypreal_le_add_order
  2324 
  2325 * Hyperreal: Separate theorems having to do with type-specific
  2326 versions of constants have been merged into theorems that apply to the
  2327 new polymorphic constants (INCOMPATIBILITY):
  2328 
  2329   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2330   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2331   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2332   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2333   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2334   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2335   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2336   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2337   STAR_diff <-- {STAR,STARC}_diff
  2338   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2339     STARC_hcomplex_of_complex}_image_subset
  2340   starset_n_Un <-- starset{Nat,C}_n_Un
  2341   starset_n_Int <-- starset{Nat,C}_n_Int
  2342   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2343   starset_n_diff <-- starset{Nat,C}_n_diff
  2344   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2345   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2346   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2347   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2348   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2349   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2350   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2351   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2352   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2353   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2354   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2355   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2356   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2357   starfun_diff <-- starfun{C,RC,CR}_diff
  2358   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2359   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2360   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2361   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2362   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2363   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2364   starfun_Id <-- starfunC_Id
  2365   starfun_approx <-- starfun{Nat,CR}_approx
  2366   starfun_capprox <-- starfun{C,RC}_capprox
  2367   starfun_abs <-- starfunNat_rabs
  2368   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2369   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2370   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2371   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2372   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2373   starfun_add_approx <-- starfunCR_add_approx
  2374   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2375   starfun_divide <-- starfun{C,CR,RC}_divide
  2376   starfun_n <-- starfun{Nat,C}_n
  2377   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2378   starfun_n_add <-- starfun{Nat,C}_n_add
  2379   starfun_n_add_minus <-- starfunNat_n_add_minus
  2380   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2381   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2382   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2383 
  2384   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2385   star_n_minus <-- {hypreal,hcomplex}_minus
  2386   star_n_diff <-- {hypreal,hcomplex}_diff
  2387   star_n_mult <-- {hypreal,hcomplex}_mult
  2388   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2389   star_n_le <-- {hypreal,hypnat}_le
  2390   star_n_less <-- {hypreal,hypnat}_less
  2391   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2392   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2393   star_n_abs <-- hypreal_hrabs
  2394   star_n_divide <-- hcomplex_divide
  2395 
  2396   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2397   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2398   star_of_diff <-- hypreal_of_real_diff
  2399   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2400   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2401   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2402   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2403   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2404   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2405   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2406   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2407   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2408   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2409   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2410   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2411   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2412   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2413   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2414   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2415   star_of_power <-- hypreal_of_real_power
  2416   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2417 
  2418 * Hyperreal: new method "transfer" that implements the transfer
  2419 principle of nonstandard analysis. With a subgoal that mentions
  2420 nonstandard types like "'a star", the command "apply transfer"
  2421 replaces it with an equivalent one that mentions only standard types.
  2422 To be successful, all free variables must have standard types; non-
  2423 standard variables must have explicit universal quantifiers.
  2424 
  2425 * Hyperreal: A theory of Taylor series.
  2426 
  2427 
  2428 *** HOLCF ***
  2429 
  2430 * Discontinued special version of 'constdefs' (which used to support
  2431 continuous functions) in favor of the general Pure one with full
  2432 type-inference.
  2433 
  2434 * New simplification procedure for solving continuity conditions; it
  2435 is much faster on terms with many nested lambda abstractions (cubic
  2436 instead of exponential time).
  2437 
  2438 * New syntax for domain package: selector names are now optional.
  2439 Parentheses should be omitted unless argument is lazy, for example:
  2440 
  2441   domain 'a stream = cons "'a" (lazy "'a stream")
  2442 
  2443 * New command 'fixrec' for defining recursive functions with pattern
  2444 matching; defining multiple functions with mutual recursion is also
  2445 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2446 sinr, or any data constructor defined by the domain package. The given
  2447 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2448 syntax and examples.
  2449 
  2450 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2451 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2452 but the proof obligation additionally includes an admissibility
  2453 requirement. The packages generate instances of class cpo or pcpo,
  2454 with continuity and strictness theorems for Rep and Abs.
  2455 
  2456 * HOLCF: Many theorems have been renamed according to a more standard naming
  2457 scheme (INCOMPATIBILITY):
  2458 
  2459   foo_inject:  "foo$x = foo$y ==> x = y"
  2460   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2461   foo_less:    "(foo$x << foo$y) = (x << y)"
  2462   foo_strict:  "foo$UU = UU"
  2463   foo_defined: "... ==> foo$x ~= UU"
  2464   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2465 
  2466 
  2467 *** ZF ***
  2468 
  2469 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2470 including the First Isomorphism Theorem (on quotienting by the kernel
  2471 of a homomorphism).
  2472 
  2473 * ZF/Simplifier: install second copy of type solver that actually
  2474 makes use of TC rules declared to Isar proof contexts (or locales);
  2475 the old version is still required for ML proof scripts.
  2476 
  2477 
  2478 *** Cube ***
  2479 
  2480 * Converted to Isar theory format; use locales instead of axiomatic
  2481 theories.
  2482 
  2483 
  2484 *** ML ***
  2485 
  2486 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2487 for ||>, ||>>, |>>,
  2488 
  2489 * Pure/library.ML no longer defines its own option datatype, but uses
  2490 that of the SML basis, which has constructors NONE and SOME instead of
  2491 None and Some, as well as exception Option.Option instead of OPTION.
  2492 The functions the, if_none, is_some, is_none have been adapted
  2493 accordingly, while Option.map replaces apsome.
  2494 
  2495 * Pure/library.ML: the exception LIST has been given up in favour of
  2496 the standard exceptions Empty and Subscript, as well as
  2497 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2498 superceded by the standard hd and tl functions etc.
  2499 
  2500 A number of basic list functions are no longer exported to the ML
  2501 toplevel, as they are variants of predefined functions.  The following
  2502 suggests how one can translate existing code:
  2503 
  2504     rev_append xs ys = List.revAppend (xs, ys)
  2505     nth_elem (i, xs) = List.nth (xs, i)
  2506     last_elem xs = List.last xs
  2507     flat xss = List.concat xss
  2508     seq fs = List.app fs
  2509     partition P xs = List.partition P xs
  2510     mapfilter f xs = List.mapPartial f xs
  2511 
  2512 * Pure/library.ML: several combinators for linear functional
  2513 transformations, notably reverse application and composition:
  2514 
  2515   x |> f                f #> g
  2516   (x, y) |-> f          f #-> g
  2517 
  2518 * Pure/library.ML: introduced/changed precedence of infix operators:
  2519 
  2520   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2521   infix 2 ?;
  2522   infix 3 o oo ooo oooo;
  2523   infix 4 ~~ upto downto;
  2524 
  2525 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2526 infix operators.
  2527 
  2528 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2529 fold_map support linear functional transformations and nesting.  For
  2530 example:
  2531 
  2532   fold f [x1, ..., xN] y =
  2533     y |> f x1 |> ... |> f xN
  2534 
  2535   (fold o fold) f [xs1, ..., xsN] y =
  2536     y |> fold f xs1 |> ... |> fold f xsN
  2537 
  2538   fold f [x1, ..., xN] =
  2539     f x1 #> ... #> f xN
  2540 
  2541   (fold o fold) f [xs1, ..., xsN] =
  2542     fold f xs1 #> ... #> fold f xsN
  2543 
  2544 * Pure/library.ML: the following selectors on type 'a option are
  2545 available:
  2546 
  2547   the:               'a option -> 'a  (*partial*)
  2548   these:             'a option -> 'a  where 'a = 'b list
  2549   the_default: 'a -> 'a option -> 'a
  2550   the_list:          'a option -> 'a list
  2551 
  2552 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2553 basic operations for association lists, following natural argument
  2554 order; moreover the explicit equality predicate passed here avoids
  2555 potentially expensive polymorphic runtime equality checks.
  2556 The old functions may be expressed as follows:
  2557 
  2558   assoc = uncurry (AList.lookup (op =))
  2559   assocs = these oo AList.lookup (op =)
  2560   overwrite = uncurry (AList.update (op =)) o swap
  2561 
  2562 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2563 
  2564   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2565   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2566 
  2567 replacing make_keylist and keyfilter (occassionally used)
  2568 Naive rewrites:
  2569 
  2570   make_keylist = AList.make
  2571   keyfilter = AList.find (op =)
  2572 
  2573 * eq_fst and eq_snd now take explicit equality parameter, thus
  2574   avoiding eqtypes. Naive rewrites:
  2575 
  2576     eq_fst = eq_fst (op =)
  2577     eq_snd = eq_snd (op =)
  2578 
  2579 * Removed deprecated apl and apr (rarely used).
  2580   Naive rewrites:
  2581 
  2582     apl (n, op) =>>= curry op n
  2583     apr (op, m) =>>= fn n => op (n, m)
  2584 
  2585 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2586 provides a reasonably efficient light-weight implementation of sets as
  2587 lists.
  2588 
  2589 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2590 few new operations; existing lookup and update are now curried to
  2591 follow natural argument order (for use with fold etc.);
  2592 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2593 
  2594 * Pure/General: output via the Isabelle channels of
  2595 writeln/warning/error etc. is now passed through Output.output, with a
  2596 hook for arbitrary transformations depending on the print_mode
  2597 (cf. Output.add_mode -- the first active mode that provides a output
  2598 function wins).  Already formatted output may be embedded into further
  2599 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2600 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2601 accommodate easy composition of diagnostic messages etc.  Programmers
  2602 rarely need to care about Output.output or Output.raw at all, with
  2603 some notable exceptions: Output.output is required when bypassing the
  2604 standard channels (writeln etc.), or in token translations to produce
  2605 properly formatted results; Output.raw is required when capturing
  2606 already output material that will eventually be presented to the user
  2607 a second time.  For the default print mode, both Output.output and
  2608 Output.raw have no effect.
  2609 
  2610 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2611 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2612 cumulative results are displayed at the end of a batch session.
  2613 
  2614 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2615 replaced by File.platform_path and File.shell_path (with appropriate
  2616 hooks).  This provides a clean interface for unusual systems where the
  2617 internal and external process view of file names are different.
  2618 
  2619 * Pure: more efficient orders for basic syntactic entities: added
  2620 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2621 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2622 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2623 orders now -- potential INCOMPATIBILITY for code that depends on a
  2624 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2625 Library.sort_strings on result).
  2626 
  2627 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2628 fold_types traverse types/terms from left to right, observing natural
  2629 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2630 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2631 
  2632 * Pure: name spaces have been refined, with significant changes of the
  2633 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2634 to extern(_table).  The plain name entry path is superceded by a
  2635 general 'naming' context, which also includes the 'policy' to produce
  2636 a fully qualified name and external accesses of a fully qualified
  2637 name; NameSpace.extend is superceded by context dependent
  2638 Sign.declare_name.  Several theory and proof context operations modify
  2639 the naming context.  Especially note Theory.restore_naming and
  2640 ProofContext.restore_naming to get back to a sane state; note that
  2641 Theory.add_path is no longer sufficient to recover from
  2642 Theory.absolute_path in particular.
  2643 
  2644 * Pure: new flags short_names (default false) and unique_names
  2645 (default true) for controlling output of qualified names.  If
  2646 short_names is set, names are printed unqualified.  If unique_names is
  2647 reset, the name prefix is reduced to the minimum required to achieve
  2648 the original result when interning again, even if there is an overlap
  2649 with earlier declarations.
  2650 
  2651 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2652 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2653 (useful for printing error messages).  INCOMPATIBILITY.
  2654 
  2655 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2656 Theory.theory are now identified, referring to the universal
  2657 Context.theory (see Pure/context.ML).  Actual signature and theory
  2658 content is managed as theory data.  The old code and interfaces were
  2659 spread over many files and structures; the new arrangement introduces
  2660 considerable INCOMPATIBILITY to gain more clarity:
  2661 
  2662   Context -- theory management operations (name, identity, inclusion,
  2663     parents, ancestors, merge, etc.), plus generic theory data;
  2664 
  2665   Sign -- logical signature and syntax operations (declaring consts,
  2666     types, etc.), plus certify/read for common entities;
  2667 
  2668   Theory -- logical theory operations (stating axioms, definitions,
  2669     oracles), plus a copy of logical signature operations (consts,
  2670     types, etc.); also a few basic management operations (Theory.copy,
  2671     Theory.merge, etc.)
  2672 
  2673 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2674 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2675 for convenience -- they merely return the theory.
  2676 
  2677 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2678 
  2679 * Pure: the Isar proof context type is already defined early in Pure
  2680 as Context.proof (note that ProofContext.context and Proof.context are
  2681 aliases, where the latter is the preferred name).  This enables other
  2682 Isabelle components to refer to that type even before Isar is present.
  2683 
  2684 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2685 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2686 any of these kinds.  For example, Sign.intern typeK is now
  2687 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2688 Theory.hide_types.  Also note that former
  2689 Theory.hide_classes/types/consts are now
  2690 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2691 internalize their arguments!  INCOMPATIBILITY.
  2692 
  2693 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2694 datatype thmref (with constructors Name and NameSelection) instead of
  2695 plain string -- INCOMPATIBILITY;
  2696 
  2697 * Pure: cases produced by proof methods specify options, where NONE
  2698 means to remove case bindings -- INCOMPATIBILITY in
  2699 (RAW_)METHOD_CASES.
  2700 
  2701 * Pure: the following operations retrieve axioms or theorems from a
  2702 theory node or theory hierarchy, respectively:
  2703 
  2704   Theory.axioms_of: theory -> (string * term) list
  2705   Theory.all_axioms_of: theory -> (string * term) list
  2706   PureThy.thms_of: theory -> (string * thm) list
  2707   PureThy.all_thms_of: theory -> (string * thm) list
  2708 
  2709 * Pure: print_tac now outputs the goal through the trace channel.
  2710 
  2711 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2712 Reference Toplevel.debug (default false) controls detailed printing
  2713 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2714 controls execution profiling -- set to 1 for time and 2 for space
  2715 (both increase the runtime).
  2716 
  2717 * Isar session: The initial use of ROOT.ML is now always timed,
  2718 i.e. the log will show the actual process times, in contrast to the
  2719 elapsed wall-clock time that the outer shell wrapper produces.
  2720 
  2721 * Simplifier: improved handling of bound variables (nameless
  2722 representation, avoid allocating new strings).  Simprocs that invoke
  2723 the Simplifier recursively should use Simplifier.inherit_bounds to
  2724 avoid local name clashes.  Failure to do so produces warnings
  2725 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2726 for further details.
  2727 
  2728 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2729 bindings for all theorems stored within a given theory; this may help
  2730 in porting non-Isar theories to Isar ones, while keeping ML proof
  2731 scripts for the time being.
  2732 
  2733 * ML operator HTML.with_charset specifies the charset begin used for
  2734 generated HTML files.  For example:
  2735 
  2736   HTML.with_charset "utf-8" use_thy "Hebrew";
  2737   HTML.with_charset "utf-8" use_thy "Chinese";
  2738 
  2739 
  2740 *** System ***
  2741 
  2742 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2743 isabelle, isatool etc.).
  2744 
  2745 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2746 isatool doc, isatool mkdir, display_drafts etc.).
  2747 
  2748 * isatool usedir: option -f allows specification of the ML file to be
  2749 used by Isabelle; default is ROOT.ML.
  2750 
  2751 * New isatool version outputs the version identifier of the Isabelle
  2752 distribution being used.
  2753 
  2754 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2755 (containing Boolean satisfiability problems) into Isabelle/HOL
  2756 theories.
  2757 
  2758 
  2759 
  2760 New in Isabelle2004 (April 2004)
  2761 --------------------------------
  2762 
  2763 *** General ***
  2764 
  2765 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2766   Replaces linorder.ML.
  2767 
  2768 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2769   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2770   (\<a>...\<z>), are now considered normal letters, and can therefore
  2771   be used anywhere where an ASCII letter (a...zA...Z) has until
  2772   now. COMPATIBILITY: This obviously changes the parsing of some
  2773   terms, especially where a symbol has been used as a binder, say
  2774   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2775   as an identifier.  Fix it by inserting a space around former
  2776   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2777   existing theory and ML files.
  2778 
  2779 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2780 
  2781 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2782   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2783   a normal (but invisible) letter. For multiple letter subscripts repeat
  2784   \<^isub> like this: x\<^isub>1\<^isub>2.
  2785 
  2786 * Pure: There are now sub-/superscripts that can span more than one
  2787   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2788   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2789   superscript. The new control characters are not identifier parts.
  2790 
  2791 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2792   content of "..." to the latex file instead of \isacntrl... . The "..."
  2793   may consist of any printable characters excluding the end bracket >.
  2794 
  2795 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2796   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2797   declare constants "final", which prevents their being given a definition
  2798   later.  It is useful for constants whose behaviour is fixed axiomatically
  2799   rather than definitionally, such as the meta-logic connectives.
  2800 
  2801 * Pure: 'instance' now handles general arities with general sorts
  2802   (i.e. intersections of classes),
  2803 
  2804 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2805   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2806   It can be changed to alter the colors/layout of generated pages.
  2807 
  2808 
  2809 *** Isar ***
  2810 
  2811 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2812   cut_tac, subgoal_tac and thin_tac:
  2813   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2814     locales are no longer forced to write Isar proof scripts.
  2815     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2816     emulations.
  2817   - INCOMPATIBILITY: names of variables to be instantiated may no
  2818     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2819     This is consistent with the instantiation attribute "where".
  2820 
  2821 * Attributes "where" and "of":
  2822   - Now take type variables of instantiated theorem into account when reading
  2823     the instantiation string.  This fixes a bug that caused instantiated
  2824     theorems to have too special types in some circumstances.
  2825   - "where" permits explicit instantiations of type variables.
  2826 
  2827 * Calculation commands "moreover" and "also" no longer interfere with
  2828   current facts ("this"), admitting arbitrary combinations with "then"
  2829   and derived forms.
  2830 
  2831 * Locales:
  2832   - Goal statements involving the context element "includes" no longer
  2833     generate theorems with internal delta predicates (those ending on
  2834     "_axioms") in the premise.
  2835     Resolve particular premise with <locale>.intro to obtain old form.
  2836   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2837     specification and "includes" elements in goal statement.
  2838   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2839     [intro?] and [elim?] (respectively) by default.
  2840   - Experimental command for instantiation of locales in proof contexts:
  2841         instantiate <label>[<attrs>]: <loc>
  2842     Instantiates locale <loc> and adds all its theorems to the current context
  2843     taking into account their attributes.  Label and attrs are optional
  2844     modifiers, like in theorem declarations.  If present, names of
  2845     instantiated theorems are qualified with <label>, and the attributes
  2846     <attrs> are applied after any attributes these theorems might have already.
  2847       If the locale has assumptions, a chained fact of the form
  2848     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2849     are derived.  The command does not support old-style locales declared
  2850     with "locale (open)".
  2851       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2852 
  2853 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2854   (Isar) contexts.
  2855 
  2856 
  2857 *** HOL ***
  2858 
  2859 * Proof import: new image HOL4 contains the imported library from
  2860   the HOL4 system with about 2500 theorems. It is imported by
  2861   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2862   can be used like any other Isabelle image.  See
  2863   HOL/Import/HOL/README for more information.
  2864 
  2865 * Simplifier:
  2866   - Much improved handling of linear and partial orders.
  2867     Reasoners for linear and partial orders are set up for type classes
  2868     "linorder" and "order" respectively, and are added to the default simpset
  2869     as solvers.  This means that the simplifier can build transitivity chains
  2870     to solve goals from the assumptions.
  2871   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2872     of blast or auto after simplification become unnecessary because the goal
  2873     is solved by simplification already.
  2874 
  2875 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2876     all proved in axiomatic type classes for semirings, rings and fields.
  2877 
  2878 * Numerics:
  2879   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2880     now formalized using the Ring_and_Field theory mentioned above.
  2881   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2882     than before, because now they are set up once in a generic manner.
  2883   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2884     Look for the general versions in Ring_and_Field (and Power if they concern
  2885     exponentiation).
  2886 
  2887 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2888 
  2889 * Records:
  2890   - Record types are now by default printed with their type abbreviation
  2891     instead of the list of all field types. This can be configured via
  2892     the reference "print_record_type_abbr".
  2893   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2894     (not enabled by default).
  2895   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2896     EX x. x = sel r to True (not enabled by default).
  2897   - Tactic "record_split_simp_tac" to split and simplify records added.
  2898 
  2899 * 'specification' command added, allowing for definition by
  2900   specification.  There is also an 'ax_specification' command that
  2901   introduces the new constants axiomatically.
  2902 
  2903 * arith(_tac) is now able to generate counterexamples for reals as well.
  2904 
  2905 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2906 
  2907 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2908   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2909 
  2910 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2911   matrix theory to linear programming.
  2912 
  2913 * Unions and Intersections:
  2914   The latex output syntax of UN and INT has been changed
  2915   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2916   i.e. the index formulae has become a subscript.
  2917   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2918 
  2919 * Unions and Intersections over Intervals:
  2920   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2921   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2922   like in normal math, and corresponding versions for < and for intersection.
  2923 
  2924 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2925   lexicographic dictonary ordering has been added as "lexord".
  2926 
  2927 * ML: the legacy theory structures Int and List have been removed. They had
  2928   conflicted with ML Basis Library structures having the same names.
  2929 
  2930 * 'refute' command added to search for (finite) countermodels.  Only works
  2931   for a fragment of HOL.  The installation of an external SAT solver is
  2932   highly recommended.  See "HOL/Refute.thy" for details.
  2933 
  2934 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2935   formulae under an assignment of free variables to random values.
  2936   In contrast to 'refute', it can deal with inductive datatypes,
  2937   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2938   for examples.
  2939 
  2940 
  2941 *** HOLCF ***
  2942 
  2943 * Streams now come with concatenation and are part of the HOLCF image
  2944 
  2945 
  2946 
  2947 New in Isabelle2003 (May 2003)
  2948 ------------------------------
  2949 
  2950 *** General ***
  2951 
  2952 * Provers/simplifier:
  2953 
  2954   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2955     Assumptions are now subject to complete mutual simplification,
  2956     not just from left to right. The simplifier now preserves
  2957     the order of assumptions.
  2958 
  2959     Potential INCOMPATIBILITY:
  2960 
  2961     -- simp sometimes diverges where the old version did
  2962        not, e.g. invoking simp on the goal
  2963 
  2964         [| P (f x); y = x; f x = f y |] ==> Q
  2965 
  2966        now gives rise to the infinite reduction sequence
  2967 
  2968         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2969 
  2970        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2971        kind of problem.
  2972 
  2973     -- Tactics combining classical reasoner and simplification (such as auto)
  2974        are also affected by this change, because many of them rely on
  2975        simp. They may sometimes diverge as well or yield a different numbers
  2976        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2977        in case of problems. Sometimes subsequent calls to the classical
  2978        reasoner will fail because a preceeding call to the simplifier too
  2979        eagerly simplified the goal, e.g. deleted redundant premises.
  2980 
  2981   - The simplifier trace now shows the names of the applied rewrite rules
  2982 
  2983   - You can limit the number of recursive invocations of the simplifier
  2984     during conditional rewriting (where the simplifie tries to solve the
  2985     conditions before applying the rewrite rule):
  2986     ML "simp_depth_limit := n"
  2987     where n is an integer. Thus you can force termination where previously
  2988     the simplifier would diverge.
  2989 
  2990   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2991 
  2992   - No longer aborts on failed congruence proof.  Instead, the
  2993     congruence is ignored.
  2994 
  2995 * Pure: New generic framework for extracting programs from constructive
  2996   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2997   as HOL/Extraction for some case studies.
  2998 
  2999 * Pure: The main goal of the proof state is no longer shown by default, only
  3000 the subgoals. This behaviour is controlled by a new flag.
  3001    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3002 (ML: Proof.show_main_goal).
  3003 
  3004 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3005 rules whose conclusion matches subgoal 1:
  3006       PG menu: Isabelle/Isar -> Show me -> matching rules
  3007 The rules are ordered by how closely they match the subgoal.
  3008 In particular, rules that solve a subgoal outright are displayed first
  3009 (or rather last, the way they are printed).
  3010 (ML: ProofGeneral.print_intros())
  3011 
  3012 * Pure: New flag trace_unify_fail causes unification to print
  3013 diagnostic information (PG: in trace buffer) when it fails. This is
  3014 useful for figuring out why single step proofs like rule, erule or
  3015 assumption failed.
  3016 
  3017 * Pure: Locale specifications now produce predicate definitions
  3018 according to the body of text (covering assumptions modulo local
  3019 definitions); predicate "loc_axioms" covers newly introduced text,
  3020 while "loc" is cumulative wrt. all included locale expressions; the
  3021 latter view is presented only on export into the global theory
  3022 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3023 on the old view without predicates;
  3024 
  3025 * Pure: predefined locales "var" and "struct" are useful for sharing
  3026 parameters (as in CASL, for example); just specify something like
  3027 ``var x + var y + struct M'' as import;
  3028 
  3029 * Pure: improved thms_containing: proper indexing of facts instead of
  3030 raw theorems; check validity of results wrt. current name space;
  3031 include local facts of proof configuration (also covers active
  3032 locales), cover fixed variables in index; may use "_" in term
  3033 specification; an optional limit for the number of printed facts may
  3034 be given (the default is 40);
  3035 
  3036 * Pure: disallow duplicate fact bindings within new-style theory files
  3037 (batch-mode only);
  3038 
  3039 * Provers: improved induct method: assumptions introduced by case
  3040 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3041 the goal statement); "foo" still refers to all facts collectively;
  3042 
  3043 * Provers: the function blast.overloaded has been removed: all constants
  3044 are regarded as potentially overloaded, which improves robustness in exchange
  3045 for slight decrease in efficiency;
  3046 
  3047 * Provers/linorder: New generic prover for transitivity reasoning over
  3048 linear orders.  Note: this prover is not efficient!
  3049 
  3050 * Isar: preview of problems to finish 'show' now produce an error
  3051 rather than just a warning (in interactive mode);
  3052 
  3053 
  3054 *** HOL ***
  3055 
  3056 * arith(_tac)
  3057 
  3058  - Produces a counter example if it cannot prove a goal.
  3059    Note that the counter example may be spurious if the goal is not a formula
  3060    of quantifier-free linear arithmetic.
  3061    In ProofGeneral the counter example appears in the trace buffer.
  3062 
  3063  - Knows about div k and mod k where k is a numeral of type nat or int.
  3064 
  3065  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3066    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3067    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3068 
  3069 * simp's arithmetic capabilities have been enhanced a bit: it now
  3070 takes ~= in premises into account (by performing a case split);
  3071 
  3072 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3073 are distributed over a sum of terms;
  3074 
  3075 * New tactic "trans_tac" and method "trans" instantiate
  3076 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3077 "<=", "<" and "=").
  3078 
  3079 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3080 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3081 
  3082 * 'typedef' command has new option "open" to suppress the set
  3083 definition;
  3084 
  3085 * functions Min and Max on finite sets have been introduced (theory
  3086 Finite_Set);
  3087 
  3088 * attribute [symmetric] now works for relations as well; it turns
  3089 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3090 
  3091 * induct over a !!-quantified statement (say !!x1..xn):
  3092   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3093 
  3094 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3095 %x. None. Warning: empty_def now refers to the previously hidden definition
  3096 of the empty set.
  3097 
  3098 * Algebra: formalization of classical algebra.  Intended as base for
  3099 any algebraic development in Isabelle.  Currently covers group theory
  3100 (up to Sylow's theorem) and ring theory (Universal Property of
  3101 Univariate Polynomials).  Contributions welcome;
  3102 
  3103 * GroupTheory: deleted, since its material has been moved to Algebra;
  3104 
  3105 * Complex: new directory of the complex numbers with numeric constants,
  3106 nonstandard complex numbers, and some complex analysis, standard and
  3107 nonstandard (Jacques Fleuriot);
  3108 
  3109 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3110 
  3111 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3112 Fleuriot);
  3113 
  3114 * Real/HahnBanach: updated and adapted to locales;
  3115 
  3116 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3117 Gray and Kramer);
  3118 
  3119 * UNITY: added the Meier-Sanders theory of progress sets;
  3120 
  3121 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3122 as abstract algorithms, instantiated to the JVM;
  3123 
  3124 * Bali: Java source language formalization. Type system, operational
  3125 semantics, axiomatic semantics. Supported language features:
  3126 classes, interfaces, objects,virtual methods, static methods,
  3127 static/instance fields, arrays, access modifiers, definite
  3128 assignment, exceptions.
  3129 
  3130 
  3131 *** ZF ***
  3132 
  3133 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3134 universe, etc.);
  3135 
  3136 * Main ZF: virtually all theories converted to new-style format;
  3137 
  3138 
  3139 *** ML ***
  3140 
  3141 * Pure: Tactic.prove provides sane interface for internal proofs;
  3142 omits the infamous "standard" operation, so this is more appropriate
  3143 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3144 
  3145 * Pure: improved error reporting of simprocs;
  3146 
  3147 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3148 up simprocs;
  3149 
  3150 
  3151 *** Document preparation ***
  3152 
  3153 * uses \par instead of \\ for line breaks in theory text. This may
  3154 shift some page breaks in large documents. To get the old behaviour
  3155 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3156 
  3157 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3158 other packages
  3159 
  3160 * \<euro> now needs package babel/greek instead of marvosym (which
  3161 broke \Rightarrow)
  3162 
  3163 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3164 textcomp package)
  3165 
  3166 
  3167 
  3168 New in Isabelle2002 (March 2002)
  3169 --------------------------------
  3170 
  3171 *** Document preparation ***
  3172 
  3173 * greatly simplified document preparation setup, including more
  3174 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3175 instructive isatool mkdir; users should basically be able to get
  3176 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3177 users may run a separate document processing stage manually like this:
  3178 "isatool usedir -D output HOL Test && isatool document Test/output";
  3179 
  3180 * theory dependency graph may now be incorporated into documents;
  3181 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3182 with \includegraphics of LaTeX;
  3183 
  3184 * proper spacing of consecutive markup elements, especially text
  3185 blocks after section headings;
  3186 
  3187 * support bold style (for single symbols only), input syntax is like
  3188 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3189 
  3190 * \<bullet> is now output as bold \cdot by default, which looks much
  3191 better in printed text;
  3192 
  3193 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3194 note that these symbols are currently unavailable in Proof General /
  3195 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3196 
  3197 * isatool latex no longer depends on changed TEXINPUTS, instead
  3198 isatool document copies the Isabelle style files to the target
  3199 location;
  3200 
  3201 
  3202 *** Isar ***
  3203 
  3204 * Pure/Provers: improved proof by cases and induction;
  3205   - 'case' command admits impromptu naming of parameters (such as
  3206     "case (Suc n)");
  3207   - 'induct' method divinates rule instantiation from the inductive
  3208     claim; no longer requires excessive ?P bindings for proper
  3209     instantiation of cases;
  3210   - 'induct' method properly enumerates all possibilities of set/type
  3211     rules; as a consequence facts may be also passed through *type*
  3212     rules without further ado;
  3213   - 'induct' method now derives symbolic cases from the *rulified*
  3214     rule (before it used to rulify cases stemming from the internal
  3215     atomized version); this means that the context of a non-atomic
  3216     statement becomes is included in the hypothesis, avoiding the
  3217     slightly cumbersome show "PROP ?case" form;
  3218   - 'induct' may now use elim-style induction rules without chaining
  3219     facts, using ``missing'' premises from the goal state; this allows
  3220     rules stemming from inductive sets to be applied in unstructured
  3221     scripts, while still benefitting from proper handling of non-atomic
  3222     statements; NB: major inductive premises need to be put first, all
  3223     the rest of the goal is passed through the induction;
  3224   - 'induct' proper support for mutual induction involving non-atomic
  3225     rule statements (uses the new concept of simultaneous goals, see
  3226     below);
  3227   - append all possible rule selections, but only use the first
  3228     success (no backtracking);
  3229   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3230   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3231   - added 'print_induct_rules' (covered by help item in recent Proof
  3232     General versions);
  3233   - moved induct/cases attributes to Pure, methods to Provers;
  3234   - generic method setup instantiated for FOL and HOL;
  3235 
  3236 * Pure: support multiple simultaneous goal statements, for example
  3237 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3238 meta-level mechanism, this acts as if several individual goals had
  3239 been stated separately; in particular common proof methods need to be
  3240 repeated in order to cover all claims; note that a single elimination
  3241 step is *not* sufficient to establish the two conjunctions, so this
  3242 fails:
  3243 
  3244   assume "A & B" then have A and B ..   (*".." fails*)
  3245 
  3246 better use "obtain" in situations as above; alternative refer to
  3247 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3248 
  3249 * Pure: proper integration with ``locales''; unlike the original
  3250 version by Florian Kammller, Isar locales package high-level proof
  3251 contexts rather than raw logical ones (e.g. we admit to include
  3252 attributes everywhere); operations on locales include merge and
  3253 rename; support for implicit arguments (``structures''); simultaneous
  3254 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3255 some examples;
  3256 
  3257 * Pure: the following commands have been ``localized'', supporting a
  3258 target locale specification "(in name)": 'lemma', 'theorem',
  3259 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3260 stored both within the locale and at the theory level (exported and
  3261 qualified by the locale name);
  3262 
  3263 * Pure: theory goals may now be specified in ``long'' form, with
  3264 ad-hoc contexts consisting of arbitrary locale elements. for example
  3265 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3266 definitions may be given, too); the result is a meta-level rule with
  3267 the context elements being discharged in the obvious way;
  3268 
  3269 * Pure: new proof command 'using' allows to augment currently used
  3270 facts after a goal statement ('using' is syntactically analogous to
  3271 'apply', but acts on the goal's facts only); this allows chained facts
  3272 to be separated into parts given before and after a claim, as in
  3273 ``from a and b have C using d and e <proof>'';
  3274 
  3275 * Pure: renamed "antecedent" case to "rule_context";
  3276 
  3277 * Pure: new 'judgment' command records explicit information about the
  3278 object-logic embedding (used by several tools internally); no longer
  3279 use hard-wired "Trueprop";
  3280 
  3281 * Pure: added 'corollary' command;
  3282 
  3283 * Pure: fixed 'token_translation' command;
  3284 
  3285 * Pure: removed obsolete 'exported' attribute;
  3286 
  3287 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3288 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3289 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3290 
  3291 * Pure: method 'atomize' presents local goal premises as object-level
  3292 statements (atomic meta-level propositions); setup controlled via
  3293 rewrite rules declarations of 'atomize' attribute; example
  3294 application: 'induct' method with proper rule statements in improper
  3295 proof *scripts*;
  3296 
  3297 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3298 now consider the syntactic context of assumptions, giving a better
  3299 chance to get type-inference of the arguments right (this is
  3300 especially important for locales);
  3301 
  3302 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3303 mode;
  3304 
  3305 * Pure/obtain: the formal conclusion "thesis", being marked as
  3306 ``internal'', may no longer be reference directly in the text;
  3307 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3308 situations;
  3309 
  3310 * Pure: generic 'sym' attribute which declares a rule both as pure
  3311 'elim?' and for the 'symmetric' operation;
  3312 
  3313 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3314 text; the fixed correlation with particular command syntax has been
  3315 discontinued;
  3316 
  3317 * Pure: new method 'rules' is particularly well-suited for proof
  3318 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3319 but often produces more compact proof terms with less detours;
  3320 
  3321 * Pure/Provers/classical: simplified integration with pure rule
  3322 attributes and methods; the classical "intro?/elim?/dest?"
  3323 declarations coincide with the pure ones; the "rule" method no longer
  3324 includes classically swapped intros; "intro" and "elim" methods no
  3325 longer pick rules from the context; also got rid of ML declarations
  3326 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3327 INCOMPATIBILITY;
  3328 
  3329 * Provers/classical: attribute 'swapped' produces classical inversions
  3330 of introduction rules;
  3331 
  3332 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3333 rules instead of full simplifier context; 'iff' attribute handles
  3334 conditional rules;
  3335 
  3336 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3337 
  3338 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3339 "(permissive)" option to recover old behavior;
  3340 
  3341 * HOL: 'inductive' no longer features separate (collective) attributes
  3342 for 'intros' (was found too confusing);
  3343 
  3344 * HOL: properly declared induction rules less_induct and
  3345 wf_induct_rule;
  3346 
  3347 
  3348 *** HOL ***
  3349 
  3350 * HOL: moved over to sane numeral syntax; the new policy is as
  3351 follows:
  3352 
  3353   - 0 and 1 are polymorphic constants, which are defined on any
  3354   numeric type (nat, int, real etc.);
  3355 
  3356   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3357   binary representation internally;
  3358 
  3359   - type nat has special constructor Suc, and generally prefers Suc 0
  3360   over 1::nat and Suc (Suc 0) over 2::nat;
  3361 
  3362 This change may cause significant problems of INCOMPATIBILITY; here
  3363 are some hints on converting existing sources:
  3364 
  3365   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3366   entities, so expressions involving "-" (unary or binary minus) need
  3367   to be spaced properly;
  3368 
  3369   - existing occurrences of "1" may need to be constraint "1::nat" or
  3370   even replaced by Suc 0; similar for old "2";
  3371 
  3372   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3373 
  3374   - remove all special provisions on numerals in proofs;
  3375 
  3376 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3377 representation (depends on bin_arith_simps in the default context);
  3378 
  3379 * HOL: symbolic syntax for x^2 (numeral 2);
  3380 
  3381 * HOL: the class of all HOL types is now called "type" rather than
  3382 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3383 in axclass/classes, instance/arities, and (usually rare) occurrences
  3384 in typings (of consts etc.); internally the class is called
  3385 "HOL.type", ML programs should refer to HOLogic.typeS;
  3386 
  3387 * HOL/record package improvements:
  3388   - new derived operations "fields" to build a partial record section,
  3389     "extend" to promote a fixed record to a record scheme, and
  3390     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3391     declared as simp by default;
  3392   - shared operations ("more", "fields", etc.) now need to be always
  3393     qualified) --- potential INCOMPATIBILITY;
  3394   - removed "make_scheme" operations (use "make" with "extend") --
  3395     INCOMPATIBILITY;
  3396   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3397   - provides cases/induct rules for use with corresponding Isar
  3398     methods (for concrete records, record schemes, concrete more
  3399     parts, and schematic more parts -- in that order);
  3400   - internal definitions directly based on a light-weight abstract
  3401     theory of product types over typedef rather than datatype;
  3402 
  3403 * HOL: generic code generator for generating executable ML code from
  3404 specifications; specific support for HOL constructs such as inductive
  3405 datatypes and sets, as well as recursive functions; can be invoked
  3406 via 'generate_code' theory section;
  3407 
  3408 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3409 
  3410 * HOL: consolidated and renamed several theories.  In particular:
  3411         Ord.thy has been absorbed into HOL.thy
  3412         String.thy has been absorbed into List.thy
  3413 
  3414 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3415 (beware of argument permutation!);
  3416 
  3417 * HOL: linorder_less_split superseded by linorder_cases;
  3418 
  3419 * HOL/List: "nodups" renamed to "distinct";
  3420 
  3421 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3422 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3423   - Ex_def has changed, now need to use some_eq_ex
  3424 
  3425 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3426 in this (rare) case use:
  3427 
  3428   delSWrapper "split_all_tac"
  3429   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3430 
  3431 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3432 MAY FAIL;
  3433 
  3434 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3435 Isabelle's type classes, ^ on functions and relations has too general
  3436 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3437 necessary to attach explicit type constraints;
  3438 
  3439 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3440 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3441 renamed accordingly (eg "compI" -> "rel_compI").
  3442 
  3443 * HOL: syntax translations now work properly with numerals and records
  3444 expressions;
  3445 
  3446 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3447 of "lam" -- INCOMPATIBILITY;
  3448 
  3449 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3450 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3451 renamed "Product_Type.unit";
  3452 
  3453 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3454 
  3455 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3456 the "cases" method);
  3457 
  3458 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3459 Florian Kammller);
  3460 
  3461 * HOL/IMP: updated and converted to new-style theory format; several
  3462 parts turned into readable document, with proper Isar proof texts and
  3463 some explanations (by Gerwin Klein);
  3464 
  3465 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3466 
  3467 * HOL-Hyperreal is now a logic image;
  3468 
  3469 
  3470 *** HOLCF ***
  3471 
  3472 * Isar: consts/constdefs supports mixfix syntax for continuous
  3473 operations;
  3474 
  3475 * Isar: domain package adapted to new-style theory format, e.g. see
  3476 HOLCF/ex/Dnat.thy;
  3477 
  3478 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3479 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3480 lift.induct_tac, always use UU instead of Undef;
  3481 
  3482 * HOLCF/IMP: updated and converted to new-style theory;
  3483 
  3484 
  3485 *** ZF ***
  3486 
  3487 * Isar: proper integration of logic-specific tools and packages,
  3488 including theory commands '(co)inductive', '(co)datatype',
  3489 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3490 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3491 
  3492 * theory Main no longer includes AC; for the Axiom of Choice, base
  3493 your theory on Main_ZFC;
  3494 
  3495 * the integer library now covers quotients and remainders, with many
  3496 laws relating division to addition, multiplication, etc.;
  3497 
  3498 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3499 typeless version of the formalism;
  3500 
  3501 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3502 format;
  3503 
  3504 * ZF/Induct: new directory for examples of inductive definitions,
  3505 including theory Multiset for multiset orderings; converted to
  3506 new-style theory format;
  3507 
  3508 * ZF: many new theorems about lists, ordinals, etc.;
  3509 
  3510 
  3511 *** General ***
  3512 
  3513 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3514 variable proof controls level of detail: 0 = no proofs (only oracle
  3515 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3516 also ref manual for further ML interfaces;
  3517 
  3518 * Pure/axclass: removed obsolete ML interface
  3519 goal_subclass/goal_arity;
  3520 
  3521 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3522 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3523 separate tokens, so expressions involving minus need to be spaced
  3524 properly;
  3525 
  3526 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3527 rather than "infixl" or "infixr";
  3528 
  3529 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3530 sort constraint specifications in type inference; e.g. "x::_::foo"
  3531 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3532 type variable);
  3533 
  3534 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3535 control output of nested => (types); the default behavior is
  3536 "type_brackets";
  3537 
  3538 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3539 tokens into AST constants;
  3540 
  3541 * Pure/syntax: prefer later declarations of translations and print
  3542 translation functions; potential INCOMPATIBILITY: need to reverse
  3543 multiple declarations for same syntax element constant;
  3544 
  3545 * Pure/show_hyps reset by default (in accordance to existing Isar
  3546 practice);
  3547 
  3548 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3549 addSafter;
  3550 
  3551 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3552 as well;
  3553 
  3554 * system: tested support for MacOS X; should be able to get Isabelle +
  3555 Proof General to work in a plain Terminal after installing Poly/ML
  3556 (e.g. from the Isabelle distribution area) and GNU bash alone
  3557 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3558 support requires further installations, e.g. from
  3559 http://fink.sourceforge.net/);
  3560 
  3561 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3562 
  3563 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3564 of 40 MB), cf. ML_OPTIONS;
  3565 
  3566 * system: Proof General keywords specification is now part of the
  3567 Isabelle distribution (see etc/isar-keywords.el);
  3568 
  3569 * system: support for persistent Proof General sessions (refrain from
  3570 outdating all loaded theories on startup); user may create writable
  3571 logic images like this: ``isabelle -q HOL Test'';
  3572 
  3573 * system: smart selection of Isabelle process versus Isabelle
  3574 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3575 run both "isabelle" and "Isabelle" even if file names are badly
  3576 damaged (executable inspects the case of the first letter of its own
  3577 name); added separate "isabelle-process" and "isabelle-interface";
  3578 
  3579 * system: refrain from any attempt at filtering input streams; no
  3580 longer support ``8bit'' encoding of old isabelle font, instead proper
  3581 iso-latin characters may now be used; the related isatools
  3582 "symbolinput" and "nonascii" have disappeared as well;
  3583 
  3584 * system: removed old "xterm" interface (the print modes "xterm" and
  3585 "xterm_color" are still available for direct use in a suitable
  3586 terminal);
  3587 
  3588 
  3589 
  3590 New in Isabelle99-2 (February 2001)
  3591 -----------------------------------
  3592 
  3593 *** Overview of INCOMPATIBILITIES ***
  3594 
  3595 * HOL: please note that theories in the Library and elsewhere often use the
  3596 new-style (Isar) format; to refer to their theorems in an ML script you must
  3597 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3598 
  3599 * HOL: inductive package no longer splits induction rule aggressively,
  3600 but only as far as specified by the introductions given; the old
  3601 format may be recovered via ML function complete_split_rule or attribute
  3602 'split_rule (complete)';
  3603 
  3604 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3605 gfp_Tarski to gfp_unfold;
  3606 
  3607 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3608 
  3609 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3610 relation); infix "^^" has been renamed "``"; infix "``" has been
  3611 renamed "`"; "univalent" has been renamed "single_valued";
  3612 
  3613 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3614 operation;
  3615 
  3616 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3617 
  3618 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3619 
  3620 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3621 consequence, it is no longer monotonic wrt. the local goal context
  3622 (which is now passed through the inductive cases);
  3623 
  3624 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3625 \<gg> to \<ggreater>;
  3626 
  3627 
  3628 *** Document preparation ***
  3629 
  3630 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3631 available: are "it" for near math-mode best-style output, "sl" for
  3632 slanted text style, and "tt" for plain type-writer; if no
  3633 \isabellestyle command is given, output is according to slanted
  3634 type-writer);
  3635 
  3636 * support sub/super scripts (for single symbols only), input syntax is
  3637 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3638 
  3639 * some more standard symbols; see Appendix A of the system manual for
  3640 the complete list of symbols defined in isabellesym.sty;
  3641 
  3642 * improved isabelle style files; more abstract symbol implementation
  3643 (should now use \isamath{...} and \isatext{...} in custom symbol
  3644 definitions);
  3645 
  3646 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3647 state; Note that presentation of goal states does not conform to
  3648 actual human-readable proof documents.  Please do not include goal
  3649 states into document output unless you really know what you are doing!
  3650 
  3651 * proper indentation of antiquoted output with proportional LaTeX
  3652 fonts;
  3653 
  3654 * no_document ML operator temporarily disables LaTeX document
  3655 generation;
  3656 
  3657 * isatool unsymbolize tunes sources for plain ASCII communication;
  3658 
  3659 
  3660 *** Isar ***
  3661 
  3662 * Pure: Isar now suffers initial goal statements to contain unbound
  3663 schematic variables (this does not conform to actual readable proof
  3664 documents, due to unpredictable outcome and non-compositional proof
  3665 checking); users who know what they are doing may use schematic goals
  3666 for Prolog-style synthesis of proven results;
  3667 
  3668 * Pure: assumption method (an implicit finishing) now handles actual
  3669 rules as well;
  3670 
  3671 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3672 initial goal, declare "that" only as Pure intro (only for single
  3673 steps); the "that" rule assumption may now be involved in implicit
  3674 finishing, thus ".." becomes a feasible for trivial obtains;
  3675 
  3676 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3677 instance proofs may be performed by "..";
  3678 
  3679 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3680 statements as well;
  3681 
  3682 * Pure: more robust selection of calculational rules;
  3683 
  3684 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3685 rule (as well as the assumption rule);
  3686 
  3687 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3688 lemmas, using the graph browser tool;
  3689 
  3690 * Pure: predict failure of "show" in interactive mode;
  3691 
  3692 * Pure: 'thms_containing' now takes actual terms as arguments;
  3693 
  3694 * HOL: improved method 'induct' --- now handles non-atomic goals
  3695 (potential INCOMPATIBILITY); tuned error handling;
  3696 
  3697 * HOL: cases and induct rules now provide explicit hints about the
  3698 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3699 any remaining facts are inserted into the goal verbatim;
  3700 
  3701 * HOL: local contexts (aka cases) may now contain term bindings as
  3702 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3703 the result to be shown in each case;
  3704 
  3705 * HOL: added 'recdef_tc' command;
  3706 
  3707 * isatool convert assists in eliminating legacy ML scripts;
  3708 
  3709 
  3710 *** HOL ***
  3711 
  3712 * HOL/Library: a collection of generic theories to be used together
  3713 with main HOL; the theory loader path already includes this directory
  3714 by default; the following existing theories have been moved here:
  3715 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3716 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3717 
  3718 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3719 modelling and verification task performed in Isabelle/HOL +
  3720 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3721 
  3722 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3723 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3724 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3725 'domain', this makes the theory consistent with mathematical
  3726 literature;
  3727 
  3728 * HOL basics: added overloaded operations "inverse" and "divide"
  3729 (infix "/"), syntax for generic "abs" operation, generic summation
  3730 operator \<Sum>;
  3731 
  3732 * HOL/typedef: simplified package, provide more useful rules (see also
  3733 HOL/subset.thy);
  3734 
  3735 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3736 now expressed as a proper nested rule (old-style tactic scripts may
  3737 require atomize_strip_tac to cope with non-atomic premises);
  3738 
  3739 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3740 to "split_conv" (old name still available for compatibility);
  3741 
  3742 * HOL: improved concrete syntax for strings (e.g. allows translation
  3743 rules with string literals);
  3744 
  3745 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3746  and Fleuriot's mechanization of analysis, including the transcendental
  3747  functions for the reals;
  3748 
  3749 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3750 
  3751 
  3752 *** CTT ***
  3753 
  3754 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3755 "lam" is displayed as TWO lambda-symbols
  3756 
  3757 * CTT: theory Main now available, containing everything (that is, Bool
  3758 and Arith);
  3759 
  3760 
  3761 *** General ***
  3762 
  3763 * Pure: the Simplifier has been implemented properly as a derived rule
  3764 outside of the actual kernel (at last!); the overall performance
  3765 penalty in practical applications is about 50%, while reliability of
  3766 the Isabelle inference kernel has been greatly improved;
  3767 
  3768 * print modes "brackets" and "no_brackets" control output of nested =>
  3769 (types) and ==> (props); the default behaviour is "brackets";
  3770 
  3771 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3772 as assumptions as well;
  3773 
  3774 * system: support Poly/ML 4.0;
  3775 
  3776 * system: isatool install handles KDE version 1 or 2;
  3777 
  3778 
  3779 
  3780 New in Isabelle99-1 (October 2000)
  3781 ----------------------------------
  3782 
  3783 *** Overview of INCOMPATIBILITIES ***
  3784 
  3785 * HOL: simplification of natural numbers is much changed; to partly
  3786 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3787 issue the following ML commands:
  3788 
  3789   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3790   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3791 
  3792 * HOL: simplification no longer dives into case-expressions; this is
  3793 controlled by "t.weak_case_cong" for each datatype t;
  3794 
  3795 * HOL: nat_less_induct renamed to less_induct;
  3796 
  3797 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3798 fixsome to patch .thy and .ML sources automatically;
  3799 
  3800   select_equality  -> some_equality
  3801   select_eq_Ex     -> some_eq_ex
  3802   selectI2EX       -> someI2_ex
  3803   selectI2         -> someI2
  3804   selectI          -> someI
  3805   select1_equality -> some1_equality
  3806   Eps_sym_eq       -> some_sym_eq_trivial
  3807   Eps_eq           -> some_eq_trivial
  3808 
  3809 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3810 
  3811 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3812 instead);
  3813 
  3814 * HOL: the recursion equations generated by 'recdef' are now called
  3815 f.simps instead of f.rules;
  3816 
  3817 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3818 
  3819 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3820 sometimes be needed;
  3821 
  3822 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3823 
  3824 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3825 
  3826 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3827 product is now "<*>" instead of "Times"; the lexicographic product is
  3828 now "<*lex*>" instead of "**";
  3829 
  3830 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3831 of main HOL, but was unused); better use HOL's datatype package;
  3832 
  3833 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3834 the old syntax may be recovered as follows:
  3835 
  3836   syntax (symbols)
  3837     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3838       (infixl "\\<oplus>" 100)
  3839 
  3840 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3841 
  3842 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3843 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3844 internally;
  3845 
  3846 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3847 changed from A/r to A//r;
  3848 
  3849 * ZF: new treatment of arithmetic (nat & int) may break some old
  3850 proofs;
  3851 
  3852 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3853 rulify -> rule_format, elimify -> elim_format, ...);
  3854 
  3855 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3856 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3857 should have to change intro!! to intro? only); replaced "delrule" by
  3858 "rule del";
  3859 
  3860 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3861 
  3862 * Provers: strengthened force_tac by using new first_best_tac;
  3863 
  3864 * LaTeX document preparation: several changes of isabelle.sty (see
  3865 lib/texinputs);
  3866 
  3867 
  3868 *** Document preparation ***
  3869 
  3870 * formal comments (text blocks etc.) in new-style theories may now
  3871 contain antiquotations of thm/prop/term/typ/text to be presented
  3872 according to latex print mode; concrete syntax is like this:
  3873 @{term[show_types] "f(x) = a + x"};
  3874 
  3875 * isatool mkdir provides easy setup of Isabelle session directories,
  3876 including proper document sources;
  3877 
  3878 * generated LaTeX sources are now deleted after successful run
  3879 (isatool document -c); may retain a copy somewhere else via -D option
  3880 of isatool usedir;
  3881 
  3882 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3883 style files, achieving self-contained LaTeX sources and simplifying
  3884 LaTeX debugging;
  3885 
  3886 * old-style theories now produce (crude) LaTeX output as well;
  3887 
  3888 * browser info session directories are now self-contained (may be put
  3889 on WWW server seperately); improved graphs of nested sessions; removed
  3890 graph for 'all sessions';
  3891 
  3892 * several improvements in isabelle style files; \isabellestyle{it}
  3893 produces fake math mode output; \isamarkupheader is now \section by
  3894 default; see lib/texinputs/isabelle.sty etc.;
  3895 
  3896 
  3897 *** Isar ***
  3898 
  3899 * Isar/Pure: local results and corresponding term bindings are now
  3900 subject to Hindley-Milner polymorphism (similar to ML); this
  3901 accommodates incremental type-inference very nicely;
  3902 
  3903 * Isar/Pure: new derived language element 'obtain' supports
  3904 generalized existence reasoning;
  3905 
  3906 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3907 support accumulation of results, without applying any rules yet;
  3908 useful to collect intermediate results without explicit name
  3909 references, and for use with transitivity rules with more than 2
  3910 premises;
  3911 
  3912 * Isar/Pure: scalable support for case-analysis type proofs: new
  3913 'case' language element refers to local contexts symbolically, as
  3914 produced by certain proof methods; internally, case names are attached
  3915 to theorems as "tags";
  3916 
  3917 * Isar/Pure: theory command 'hide' removes declarations from
  3918 class/type/const name spaces;
  3919 
  3920 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3921 indicate potential overloading;
  3922 
  3923 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3924 
  3925 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3926 "{a,b,c}" instead of {a,b,c};
  3927 
  3928 * Isar/Pure now provides its own version of intro/elim/dest
  3929 attributes; useful for building new logics, but beware of confusion
  3930 with the version in Provers/classical;
  3931 
  3932 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3933 case name 'antecedent';
  3934 
  3935 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3936 to the current context is now done automatically);
  3937 
  3938 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3939 for definining proof methods in ML;
  3940 
  3941 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3942 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3943 most cases, one should have to change intro!! to intro? only);
  3944 replaced "delrule" by "rule del";
  3945 
  3946 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3947 'symmetric' attribute (the latter supercedes [RS sym]);
  3948 
  3949 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3950 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3951 well (including splits);
  3952 
  3953 * Isar/Provers: Simplifier and Classical methods now support all kind
  3954 of modifiers used in the past, including 'cong', 'iff', etc.
  3955 
  3956 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3957 of Simplifier and Classical reasoner);
  3958 
  3959 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3960 now support named cases; major packages (inductive, datatype, primrec,
  3961 recdef) support case names and properly name parameters;
  3962 
  3963 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3964 monotonicity conditions are extracted to be proven at end of
  3965 calculations;
  3966 
  3967 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3968 method anyway;
  3969 
  3970 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3971 split_if split_if_asm; datatype package provides theorems foo.splits =
  3972 foo.split foo.split_asm for each datatype;
  3973 
  3974 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3975 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3976 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3977 use "(cases (simplified))" method in proper proof texts);
  3978 
  3979 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3980 
  3981 * Isar: names of theorems etc. may be natural numbers as well;
  3982 
  3983 * Isar: 'pr' command: optional arguments for goals_limit and
  3984 ProofContext.prems_limit; no longer prints theory contexts, but only
  3985 proof states;
  3986 
  3987 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3988 additional print modes to be specified; e.g. "pr(latex)" will print
  3989 proof state according to the Isabelle LaTeX style;
  3990 
  3991 * Isar: improved support for emulating tactic scripts, including proof
  3992 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3993 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3994 (for HOL datatypes);
  3995 
  3996 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3997 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3998 'proof method scripts' have to be in depth-first order;
  3999 
  4000 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4001 
  4002 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4003 should instead use individual commands for printing items
  4004 (print_commands, print_methods etc.);
  4005 
  4006 * Isar: added 'nothing' --- the empty list of theorems;
  4007 
  4008 
  4009 *** HOL ***
  4010 
  4011 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4012 corresponding virtual machine and a specification of its bytecode
  4013 verifier and a lightweight bytecode verifier, including proofs of
  4014 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4015 Cornelia Pusch (see also the homepage of project Bali at
  4016 http://isabelle.in.tum.de/Bali/);
  4017 
  4018 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4019 Clemens Ballarin;
  4020 
  4021 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4022 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4023 Rasmussen;
  4024 
  4025 * HOL/Lattice: fundamental concepts of lattice theory and order
  4026 structures, including duals, properties of bounds versus algebraic
  4027 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4028 Theorem for complete lattices etc.; may also serve as a demonstration
  4029 for abstract algebraic reasoning using axiomatic type classes, and
  4030 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4031 
  4032 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4033 von Oheimb;
  4034 
  4035 * HOL/IMPP: extension of IMP with local variables and mutually
  4036 recursive procedures, by David von Oheimb;
  4037 
  4038 * HOL/Lambda: converted into new-style theory and document;
  4039 
  4040 * HOL/ex/Multiquote: example of multiple nested quotations and
  4041 anti-quotations -- basically a generalized version of de-Bruijn
  4042 representation; very useful in avoiding lifting of operations;
  4043 
  4044 * HOL/record: added general record equality rule to simpset; fixed
  4045 select-update simplification procedure to handle extended records as
  4046 well; admit "r" as field name;
  4047 
  4048 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4049 other numeric types and also as the identity of groups, rings, etc.;
  4050 
  4051 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4052 Types nat and int belong to this axclass;
  4053 
  4054 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4055    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4056    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4057   two terms #m*u and #n*u are replaced by #(m+n)*u
  4058     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4059   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4060     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4061 
  4062 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4063 powerful prover for predicate logic but knows nothing of clasets; see
  4064 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4065 
  4066 * HOL: new version of "case_tac" subsumes both boolean case split and
  4067 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4068 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4069 
  4070 * HOL: simplification no longer dives into case-expressions: only the
  4071 selector expression is simplified, but not the remaining arms; to
  4072 enable full simplification of case-expressions for datatype t, you may
  4073 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4074 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4075 
  4076 * HOL/recdef: the recursion equations generated by 'recdef' for
  4077 function 'f' are now called f.simps instead of f.rules; if all
  4078 termination conditions are proved automatically, these simplification
  4079 rules are added to the simpset, as in primrec; rules may be named
  4080 individually as well, resulting in a separate list of theorems for
  4081 each equation;
  4082 
  4083 * HOL/While is a new theory that provides a while-combinator. It
  4084 permits the definition of tail-recursive functions without the
  4085 provision of a termination measure. The latter is necessary once the
  4086 invariant proof rule for while is applied.
  4087 
  4088 * HOL: new (overloaded) notation for the set of elements below/above
  4089 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4090 
  4091 * HOL: theorems impI, allI, ballI bound as "strip";
  4092 
  4093 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4094 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4095 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4096 
  4097 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4098 
  4099 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4100 main HOL, but was unused);
  4101 
  4102 * HOL: fewer consts declared as global (e.g. have to refer to
  4103 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4104 
  4105 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4106 in case of overlap with user translations (e.g. judgements over
  4107 tuples); (note that the underlying logical represenation is still
  4108 bogus);
  4109 
  4110 
  4111 *** ZF ***
  4112 
  4113 * ZF: simplification automatically cancels common terms in arithmetic
  4114 expressions over nat and int;
  4115 
  4116 * ZF: new treatment of nat to minimize type-checking: all operators
  4117 coerce their operands to a natural number using the function natify,
  4118 making the algebraic laws unconditional;
  4119 
  4120 * ZF: as above, for int: operators coerce their operands to an integer
  4121 using the function intify;
  4122 
  4123 * ZF: the integer library now contains many of the usual laws for the
  4124 orderings, including $<=, and monotonicity laws for $+ and $*;
  4125 
  4126 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4127 simplification;
  4128 
  4129 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4130 to the simplifier and classical reasoner simultaneously;
  4131 
  4132 
  4133 *** General ***
  4134 
  4135 * Provers: blast_tac now handles actual object-logic rules as
  4136 assumptions; note that auto_tac uses blast_tac internally as well;
  4137 
  4138 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4139 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4140 
  4141 * Provers: delrules now handles destruct rules as well (no longer need
  4142 explicit make_elim);
  4143 
  4144 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4145   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4146 use instead the strong form,
  4147   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4148 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4149 from destruct-rules;
  4150 
  4151 * Provers: Simplifier.easy_setup provides a fast path to basic
  4152 Simplifier setup for new object-logics;
  4153 
  4154 * Pure: AST translation rules no longer require constant head on LHS;
  4155 
  4156 * Pure: improved name spaces: ambiguous output is qualified; support
  4157 for hiding of names;
  4158 
  4159 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4160 XSYMBOL_HOME; no longer need to do manual configuration in most
  4161 situations;
  4162 
  4163 * system: compression of ML heaps images may now be controlled via -c
  4164 option of isabelle and isatool usedir (currently only observed by
  4165 Poly/ML);
  4166 
  4167 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4168 useful for remote X11);
  4169 
  4170 * system: provide TAGS file for Isabelle sources;
  4171 
  4172 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4173 order;
  4174 
  4175 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4176 timing flag supersedes proof_timing and Toplevel.trace;
  4177 
  4178 * ML: new combinators |>> and |>>> for incremental transformations
  4179 with secondary results (e.g. certain theory extensions):
  4180 
  4181 * ML: PureThy.add_defs gets additional argument to indicate potential
  4182 overloading (usually false);
  4183 
  4184 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4185 results;
  4186 
  4187 
  4188 
  4189 New in Isabelle99 (October 1999)
  4190 --------------------------------
  4191 
  4192 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4193 
  4194 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4195 are no longer simplified.  (This allows the simplifier to unfold recursive
  4196 functional programs.)  To restore the old behaviour, declare
  4197 
  4198     Delcongs [if_weak_cong];
  4199 
  4200 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4201 complement;
  4202 
  4203 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4204 
  4205 * HOL/datatype: mutual_induct_tac no longer exists --
  4206   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4207 
  4208 * HOL/typedef: fixed type inference for representing set; type
  4209 arguments now have to occur explicitly on the rhs as type constraints;
  4210 
  4211 * ZF: The con_defs part of an inductive definition may no longer refer
  4212 to constants declared in the same theory;
  4213 
  4214 * HOL, ZF: the function mk_cases, generated by the inductive
  4215 definition package, has lost an argument.  To simplify its result, it
  4216 uses the default simpset instead of a supplied list of theorems.
  4217 
  4218 * HOL/List: the constructors of type list are now Nil and Cons;
  4219 
  4220 * Simplifier: the type of the infix ML functions
  4221         setSSolver addSSolver setSolver addSolver
  4222 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4223 for packaging solvers. A solver is created via
  4224         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4225 where the string argument is only a comment.
  4226 
  4227 
  4228 *** Proof tools ***
  4229 
  4230 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4231 decision procedure for linear arithmetic. Currently it is used for
  4232 types `nat', `int', and `real' in HOL (see below); it can, should and
  4233 will be instantiated for other types and logics as well.
  4234 
  4235 * The simplifier now accepts rewrite rules with flexible heads, eg
  4236      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4237   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4238   matching.
  4239 
  4240 
  4241 *** General ***
  4242 
  4243 * New Isabelle/Isar subsystem provides an alternative to traditional
  4244 tactical theorem proving; together with the ProofGeneral/isar user
  4245 interface it offers an interactive environment for developing human
  4246 readable proof documents (Isar == Intelligible semi-automated
  4247 reasoning); for further information see isatool doc isar-ref,
  4248 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4249 
  4250 * improved and simplified presentation of theories: better HTML markup
  4251 (including colors), graph views in several sizes; isatool usedir now
  4252 provides a proper interface for user theories (via -P option); actual
  4253 document preparation based on (PDF)LaTeX is available as well (for
  4254 new-style theories only); see isatool doc system for more information;
  4255 
  4256 * native support for Proof General, both for classic Isabelle and
  4257 Isabelle/Isar;
  4258 
  4259 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4260 using the graph browser tool;
  4261 
  4262 * Isabelle manuals now also available as PDF;
  4263 
  4264 * theory loader rewritten from scratch (may not be fully
  4265 bug-compatible); old loadpath variable has been replaced by show_path,
  4266 add_path, del_path, reset_path functions; new operations such as
  4267 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4268 isatool doc ref);
  4269 
  4270 * improved isatool install: option -k creates KDE application icon,
  4271 option -p DIR installs standalone binaries;
  4272 
  4273 * added ML_PLATFORM setting (useful for cross-platform installations);
  4274 more robust handling of platform specific ML images for SML/NJ;
  4275 
  4276 * the settings environment is now statically scoped, i.e. it is never
  4277 created again in sub-processes invoked from isabelle, isatool, or
  4278 Isabelle;
  4279 
  4280 * path element specification '~~' refers to '$ISABELLE_HOME';
  4281 
  4282 * in locales, the "assumes" and "defines" parts may be omitted if
  4283 empty;
  4284 
  4285 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4286 long arrows);
  4287 
  4288 * new print_mode "HTML";
  4289 
  4290 * new flag show_tags controls display of tags of theorems (which are
  4291 basically just comments that may be attached by some tools);
  4292 
  4293 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4294 mode and goal output format:
  4295 
  4296 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4297 244c244
  4298 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4299 ---
  4300 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4301 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4302 181c181
  4303 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4304 ---
  4305 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4306 
  4307 * function bind_thms stores lists of theorems (cf. bind_thm);
  4308 
  4309 * new shorthand tactics ftac, eatac, datac, fatac;
  4310 
  4311 * qed (and friends) now accept "" as result name; in that case the
  4312 theorem is not stored, but proper checks and presentation of the
  4313 result still apply;
  4314 
  4315 * theorem database now also indexes constants "Trueprop", "all",
  4316 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4317 
  4318 
  4319 *** HOL ***
  4320 
  4321 ** HOL arithmetic **
  4322 
  4323 * There are now decision procedures for linear arithmetic over nat and
  4324 int:
  4325 
  4326 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4327 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4328 are treated as atomic; subformulae not involving type `nat' or `int'
  4329 are ignored; quantified subformulae are ignored unless they are
  4330 positive universal or negative existential. The tactic has to be
  4331 invoked by hand and can be a little bit slow. In particular, the
  4332 running time is exponential in the number of occurrences of `min' and
  4333 `max', and `-' on `nat'.
  4334 
  4335 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4336 (negated) (in)equalities among the premises and the conclusion into
  4337 account (i.e. no compound formulae) and does not know about `min' and
  4338 `max', and `-' on `nat'. It is fast and is used automatically by the
  4339 simplifier.
  4340 
  4341 NB: At the moment, these decision procedures do not cope with mixed
  4342 nat/int formulae where the two parts interact, such as `m < n ==>
  4343 int(m) < int(n)'.
  4344 
  4345 * HOL/Numeral provides a generic theory of numerals (encoded
  4346 efficiently as bit strings); setup for types nat/int/real is in place;
  4347 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4348 int, existing theories and proof scripts may require a few additional
  4349 type constraints;
  4350 
  4351 * integer division and remainder can now be performed on constant
  4352 arguments;
  4353 
  4354 * many properties of integer multiplication, division and remainder
  4355 are now available;
  4356 
  4357 * An interface to the Stanford Validity Checker (SVC) is available through the
  4358 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4359 are proved automatically.  SVC must be installed separately, and its results
  4360 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4361 invocation of the underlying oracle).  For SVC see
  4362   http://verify.stanford.edu/SVC
  4363 
  4364 * IsaMakefile: the HOL-Real target now builds an actual image;
  4365 
  4366 
  4367 ** HOL misc **
  4368 
  4369 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4370 (in Isabelle/Isar) -- by Gertrud Bauer;
  4371 
  4372 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4373 analysis for assembly languages with subtypes;
  4374 
  4375 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4376 -- avoids syntactic ambiguities and treats state, transition, and
  4377 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4378 changed syntax and (many) tactics;
  4379 
  4380 * HOL/inductive: Now also handles more general introduction rules such
  4381   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4382   theorems are now maintained within the theory (maintained via the
  4383   "mono" attribute);
  4384 
  4385 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4386   (using function types) such as
  4387 
  4388   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4389 
  4390 * HOL/record: record_simproc (part of the default simpset) takes care
  4391 of selectors applied to updated records; record_split_tac is no longer
  4392 part of the default claset; update_defs may now be removed from the
  4393 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4394 
  4395   claset_ref () := claset() addSWrapper record_split_wrapper;
  4396   Delsimprocs [record_simproc]
  4397 
  4398 * HOL/typedef: fixed type inference for representing set; type
  4399 arguments now have to occur explicitly on the rhs as type constraints;
  4400 
  4401 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4402 names rather than an ML expression;
  4403 
  4404 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4405 supplied later.  Program schemes can be defined, such as
  4406     "While B C s = (if B s then While B C (C s) else s)"
  4407 where the well-founded relation can be chosen after B and C have been given.
  4408 
  4409 * HOL/List: the constructors of type list are now Nil and Cons;
  4410 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4411 course, ML tools referring to List.list.op # etc. have to be adapted;
  4412 
  4413 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4414 disabled by default; run isabelle with option -m HOL to get back to
  4415 the original Gordon/HOL-style output;
  4416 
  4417 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4418 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4419 
  4420 * HOL basic syntax simplified (more orthogonal): all variants of
  4421 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4422 Eps operator is provided as well: "SOME x. P[x]";
  4423 
  4424 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4425 
  4426 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4427 thus available for user theories;
  4428 
  4429 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4430 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4431 time;
  4432 
  4433 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4434 several times and then mp;
  4435 
  4436 
  4437 *** LK ***
  4438 
  4439 * the notation <<...>> is now available as a notation for sequences of
  4440 formulas;
  4441 
  4442 * the simplifier is now installed
  4443 
  4444 * the axiom system has been generalized (thanks to Soren Heilmann)
  4445 
  4446 * the classical reasoner now has a default rule database
  4447 
  4448 
  4449 *** ZF ***
  4450 
  4451 * new primrec section allows primitive recursive functions to be given
  4452 directly (as in HOL) over datatypes and the natural numbers;
  4453 
  4454 * new tactics induct_tac and exhaust_tac for induction (or case
  4455 analysis) over datatypes and the natural numbers;
  4456 
  4457 * the datatype declaration of type T now defines the recursor T_rec;
  4458 
  4459 * simplification automatically does freeness reasoning for datatype
  4460 constructors;
  4461 
  4462 * automatic type-inference, with AddTCs command to insert new
  4463 type-checking rules;
  4464 
  4465 * datatype introduction rules are now added as Safe Introduction rules
  4466 to the claset;
  4467 
  4468 * the syntax "if P then x else y" is now available in addition to
  4469 if(P,x,y);
  4470 
  4471 
  4472 *** Internal programming interfaces ***
  4473 
  4474 * tuned simplifier trace output; new flag debug_simp;
  4475 
  4476 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4477 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4478 
  4479 * AxClass.axclass_tac lost the theory argument;
  4480 
  4481 * tuned current_goals_markers semantics: begin / end goal avoids
  4482 printing empty lines;
  4483 
  4484 * removed prs and prs_fn hook, which was broken because it did not
  4485 include \n in its semantics, forcing writeln to add one
  4486 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4487 string -> unit if you really want to output text without newline;
  4488 
  4489 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4490 plain output, interface builders may have to enable 'isabelle_font'
  4491 mode to get Isabelle font glyphs as before;
  4492 
  4493 * refined token_translation interface; INCOMPATIBILITY: output length
  4494 now of type real instead of int;
  4495 
  4496 * theory loader actions may be traced via new ThyInfo.add_hook
  4497 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4498 your own database of information attached to *whole* theories -- as
  4499 opposed to intra-theory data slots offered via TheoryDataFun;
  4500 
  4501 * proper handling of dangling sort hypotheses (at last!);
  4502 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4503 extra sort hypotheses that can be witnessed from the type signature;
  4504 the force_strip_shyps flag is gone, any remaining shyps are simply
  4505 left in the theorem (with a warning issued by strip_shyps_warning);
  4506 
  4507 
  4508 
  4509 New in Isabelle98-1 (October 1998)
  4510 ----------------------------------
  4511 
  4512 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4513 
  4514 * several changes of automated proof tools;
  4515 
  4516 * HOL: major changes to the inductive and datatype packages, including
  4517 some minor incompatibilities of theory syntax;
  4518 
  4519 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4520 called `inj_on';
  4521 
  4522 * HOL: removed duplicate thms in Arith:
  4523   less_imp_add_less  should be replaced by  trans_less_add1
  4524   le_imp_add_le      should be replaced by  trans_le_add1
  4525 
  4526 * HOL: unary minus is now overloaded (new type constraints may be
  4527 required);
  4528 
  4529 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4530 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4531 now taken as an integer constant.
  4532 
  4533 * Pure: ML function 'theory_of' renamed to 'theory';
  4534 
  4535 
  4536 *** Proof tools ***
  4537 
  4538 * Simplifier:
  4539   1. Asm_full_simp_tac is now more aggressive.
  4540      1. It will sometimes reorient premises if that increases their power to
  4541         simplify.
  4542      2. It does no longer proceed strictly from left to right but may also
  4543         rotate premises to achieve further simplification.
  4544      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4545      old Asm_full_simp_tac in that it does not rotate premises.
  4546   2. The simplifier now knows a little bit about nat-arithmetic.
  4547 
  4548 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4549 allows for selected deletion of wrappers, by introduction of names for
  4550 wrapper functionals.  This implies that addbefore, addSbefore,
  4551 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4552 and that adding two tactics with the same name overwrites the first
  4553 one (emitting a warning).
  4554   type wrapper = (int -> tactic) -> (int -> tactic)
  4555   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4556   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4557   delWrapper, delSWrapper: claset *  string            -> claset
  4558   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4559 
  4560 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4561 semantics; addbefore now affects only the unsafe part of step_tac
  4562 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4563 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4564 by Force_tac;
  4565 
  4566 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4567 compWrapper; added safe wrapper (and access functions for it);
  4568 
  4569 * HOL/split_all_tac is now much faster and fails if there is nothing
  4570 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4571 and the names of the automatically generated variables have changed.
  4572 split_all_tac has moved within claset() from unsafe wrappers to safe
  4573 wrappers, which means that !!-bound variables are split much more
  4574 aggressively, and safe_tac and clarify_tac now split such variables.
  4575 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4576 Note: the same holds for record_split_tac, which does the job of
  4577 split_all_tac for record fields.
  4578 
  4579 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4580 permanently to the default simpset using Addsplits just like
  4581 Addsimps. They can be removed via Delsplits just like
  4582 Delsimps. Lower-case versions are also available.
  4583 
  4584 * HOL/Simplifier: The rule split_if is now part of the default
  4585 simpset. This means that the simplifier will eliminate all occurrences
  4586 of if-then-else in the conclusion of a goal. To prevent this, you can
  4587 either remove split_if completely from the default simpset by
  4588 `Delsplits [split_if]' or remove it in a specific call of the
  4589 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4590 other case splitting rules to/from the default simpset: every datatype
  4591 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4592 t is the name of the datatype).
  4593 
  4594 * Classical reasoner / Simplifier combination: new force_tac (and
  4595 derivatives Force_tac, force) combines rewriting and classical
  4596 reasoning (and whatever other tools) similarly to auto_tac, but is
  4597 aimed to solve the given subgoal completely.
  4598 
  4599 
  4600 *** General ***
  4601 
  4602 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4603 and `goalw': the theory is no longer needed as an explicit argument -
  4604 the current theory context is used; assumptions are no longer returned
  4605 at the ML-level unless one of them starts with ==> or !!; it is
  4606 recommended to convert to these new commands using isatool fixgoal
  4607 (backup your sources first!);
  4608 
  4609 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4610 the current theory context, and 'theory' to lookup stored theories;
  4611 
  4612 * new theory section 'locale' for declaring constants, assumptions and
  4613 definitions that have local scope;
  4614 
  4615 * new theory section 'nonterminals' for purely syntactic types;
  4616 
  4617 * new theory section 'setup' for generic ML setup functions
  4618 (e.g. package initialization);
  4619 
  4620 * the distribution now includes Isabelle icons: see
  4621 lib/logo/isabelle-{small,tiny}.xpm;
  4622 
  4623 * isatool install - install binaries with absolute references to
  4624 ISABELLE_HOME/bin;
  4625 
  4626 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4627 
  4628 * print mode 'emacs' reserved for Isamode;
  4629 
  4630 * support multiple print (ast) translations per constant name;
  4631 
  4632 * theorems involving oracles are now printed with a suffixed [!];
  4633 
  4634 
  4635 *** HOL ***
  4636 
  4637 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4638 
  4639 * HOL/inductive package reorganized and improved: now supports mutual
  4640 definitions such as
  4641 
  4642   inductive EVEN ODD
  4643     intrs
  4644       null "0 : EVEN"
  4645       oddI "n : EVEN ==> Suc n : ODD"
  4646       evenI "n : ODD ==> Suc n : EVEN"
  4647 
  4648 new theorem list "elims" contains an elimination rule for each of the
  4649 recursive sets; inductive definitions now handle disjunctive premises
  4650 correctly (also ZF);
  4651 
  4652 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4653 "mutual_induct" no longer exists - the induction rule is always
  4654 contained in "induct";
  4655 
  4656 
  4657 * HOL/datatype package re-implemented and greatly improved: now
  4658 supports mutually recursive datatypes such as
  4659 
  4660   datatype
  4661     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4662             | SUM ('a aexp) ('a aexp)
  4663             | DIFF ('a aexp) ('a aexp)
  4664             | NUM 'a
  4665   and
  4666     'a bexp = LESS ('a aexp) ('a aexp)
  4667             | AND ('a bexp) ('a bexp)
  4668             | OR ('a bexp) ('a bexp)
  4669 
  4670 as well as indirectly recursive datatypes such as
  4671 
  4672   datatype
  4673     ('a, 'b) term = Var 'a
  4674                   | App 'b ((('a, 'b) term) list)
  4675 
  4676 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4677 induction on mutually / indirectly recursive datatypes.
  4678 
  4679 Primrec equations are now stored in theory and can be accessed via
  4680 <function_name>.simps.
  4681 
  4682 INCOMPATIBILITIES:
  4683 
  4684   - Theories using datatypes must now have theory Datatype as an
  4685     ancestor.
  4686   - The specific <typename>.induct_tac no longer exists - use the
  4687     generic induct_tac instead.
  4688   - natE has been renamed to nat.exhaust - use exhaust_tac
  4689     instead of res_inst_tac ... natE. Note that the variable
  4690     names in nat.exhaust differ from the names in natE, this
  4691     may cause some "fragile" proofs to fail.
  4692   - The theorems split_<typename>_case and split_<typename>_case_asm
  4693     have been renamed to <typename>.split and <typename>.split_asm.
  4694   - Since default sorts of type variables are now handled correctly,
  4695     some datatype definitions may have to be annotated with explicit
  4696     sort constraints.
  4697   - Primrec definitions no longer require function name and type
  4698     of recursive argument.
  4699 
  4700 Consider using isatool fixdatatype to adapt your theories and proof
  4701 scripts to the new package (backup your sources first!).
  4702 
  4703 
  4704 * HOL/record package: considerably improved implementation; now
  4705 includes concrete syntax for record types, terms, updates; theorems
  4706 for surjective pairing and splitting !!-bound record variables; proof
  4707 support is as follows:
  4708 
  4709   1) standard conversions (selectors or updates applied to record
  4710 constructor terms) are part of the standard simpset;
  4711 
  4712   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4713 made part of standard simpset and claset via addIffs;
  4714 
  4715   3) a tactic for record field splitting (record_split_tac) is part of
  4716 the standard claset (addSWrapper);
  4717 
  4718 To get a better idea about these rules you may retrieve them via
  4719 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4720 the name of your record type.
  4721 
  4722 The split tactic 3) conceptually simplifies by the following rule:
  4723 
  4724   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4725 
  4726 Thus any record variable that is bound by meta-all will automatically
  4727 blow up into some record constructor term, consequently the
  4728 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4729 solve record problems automatically.
  4730 
  4731 
  4732 * reorganized the main HOL image: HOL/Integ and String loaded by
  4733 default; theory Main includes everything;
  4734 
  4735 * automatic simplification of integer sums and comparisons, using cancellation;
  4736 
  4737 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4738 
  4739 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4740 
  4741 * many new identities for unions, intersections, set difference, etc.;
  4742 
  4743 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4744 called split_if, split_split, split_sum_case and split_nat_case (to go
  4745 with add/delsplits);
  4746 
  4747 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4748 (?x::unit) = (); this is made part of the default simpset, which COULD
  4749 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4750 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4751 unit_abs_eta_conv is added in order to counter the effect of
  4752 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4753 %u.f();
  4754 
  4755 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4756 makes more sense);
  4757 
  4758 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4759   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4760   disjointness reasoning but breaking a few old proofs.
  4761 
  4762 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4763 to 'converse' from 'inverse' (for compatibility with ZF and some
  4764 literature);
  4765 
  4766 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4767 the well-founded relation;
  4768 
  4769 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4770     Compl A.  The "Compl" syntax remains available as input syntax for this
  4771     release ONLY.
  4772 
  4773 * HOL/Update: new theory of function updates:
  4774     f(a:=b) == %x. if x=a then b else f x
  4775 may also be iterated as in f(a:=b,c:=d,...);
  4776 
  4777 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4778 
  4779 * HOL/List:
  4780   - new function list_update written xs[i:=v] that updates the i-th
  4781     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4782   - new function `upt' written [i..j(] which generates the list
  4783     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4784     bound write [i..j], which is a shorthand for [i..j+1(].
  4785   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4786 
  4787 * HOL/Arith:
  4788   - removed 'pred' (predecessor) function;
  4789   - generalized some theorems about n-1;
  4790   - many new laws about "div" and "mod";
  4791   - new laws about greatest common divisors (see theory ex/Primes);
  4792 
  4793 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4794 instead of "inverse";
  4795 
  4796 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4797   of the multiset ordering;
  4798 
  4799 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4800   (not included by default);
  4801 
  4802 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4803 
  4804 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4805   programs, i.e. different program variables may have different types.
  4806 
  4807 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4808   [previously, this check worked only if the rewrite rule was unconditional]
  4809   Now rew can involve either definitions or equalities (either == or =).
  4810 
  4811 
  4812 *** ZF ***
  4813 
  4814 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4815   only the theorems proved on ZF.ML;
  4816 
  4817 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4818   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4819   disjointness reasoning but breaking a few old proofs.
  4820 
  4821 * ZF/Update: new theory of function updates
  4822     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4823   may also be iterated as in f(a:=b,c:=d,...);
  4824 
  4825 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4826 
  4827 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4828   [previously, this check worked only if the rewrite rule was unconditional]
  4829   Now rew can involve either definitions or equalities (either == or =).
  4830 
  4831 * case_tac provided for compatibility with HOL
  4832     (like the old excluded_middle_tac, but with subgoals swapped)
  4833 
  4834 
  4835 *** Internal programming interfaces ***
  4836 
  4837 * Pure: several new basic modules made available for general use, see
  4838 also src/Pure/README;
  4839 
  4840 * improved the theory data mechanism to support encapsulation (data
  4841 kind name replaced by private Object.kind, acting as authorization
  4842 key); new type-safe user interface via functor TheoryDataFun; generic
  4843 print_data function becomes basically useless;
  4844 
  4845 * removed global_names compatibility flag -- all theory declarations
  4846 are qualified by default;
  4847 
  4848 * module Pure/Syntax now offers quote / antiquote translation
  4849 functions (useful for Hoare logic etc. with implicit dependencies);
  4850 see HOL/ex/Antiquote for an example use;
  4851 
  4852 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4853 cterm -> thm;
  4854 
  4855 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4856 subgoal;
  4857 
  4858 * Display.print_goals function moved to Locale.print_goals;
  4859 
  4860 * standard print function for goals supports current_goals_markers
  4861 variable for marking begin of proof, end of proof, start of goal; the
  4862 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4863 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4864 for example;
  4865 
  4866 
  4867 
  4868 New in Isabelle98 (January 1998)
  4869 --------------------------------
  4870 
  4871 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4872 
  4873 * changed lexical syntax of terms / types: dots made part of long
  4874 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4875 
  4876 * simpset (and claset) reference variable replaced by functions
  4877 simpset / simpset_ref;
  4878 
  4879 * no longer supports theory aliases (via merge) and non-trivial
  4880 implicit merge of thms' signatures;
  4881 
  4882 * most internal names of constants changed due to qualified names;
  4883 
  4884 * changed Pure/Sequence interface (see Pure/seq.ML);
  4885 
  4886 
  4887 *** General Changes ***
  4888 
  4889 * hierachically structured name spaces (for consts, types, axms, thms
  4890 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4891 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4892 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4893 long_names for fully qualified output names; NOTE: ML programs
  4894 (special tactics, packages etc.) referring to internal names may have
  4895 to be adapted to cope with fully qualified names; in case of severe
  4896 backward campatibility problems try setting 'global_names' at compile
  4897 time to have enrything declared within a flat name space; one may also
  4898 fine tune name declarations in theories via the 'global' and 'local'
  4899 section;
  4900 
  4901 * reimplemented the implicit simpset and claset using the new anytype
  4902 data filed in signatures; references simpset:simpset ref etc. are
  4903 replaced by functions simpset:unit->simpset and
  4904 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4905 to patch your ML files accordingly;
  4906 
  4907 * HTML output now includes theory graph data for display with Java
  4908 applet or isatool browser; data generated automatically via isatool
  4909 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4910 
  4911 * defs may now be conditional; improved rewrite_goals_tac to handle
  4912 conditional equations;
  4913 
  4914 * defs now admits additional type arguments, using TYPE('a) syntax;
  4915 
  4916 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4917 creates a new theory node; implicit merge of thms' signatures is
  4918 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4919 transfer:theory->thm->thm in (rare) cases;
  4920 
  4921 * improved handling of draft signatures / theories; draft thms (and
  4922 ctyps, cterms) are automatically promoted to real ones;
  4923 
  4924 * slightly changed interfaces for oracles: admit many per theory, named
  4925 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4926 
  4927 * print_goals: optional output of const types (set show_consts and
  4928 show_types);
  4929 
  4930 * improved output of warnings (###) and errors (***);
  4931 
  4932 * subgoal_tac displays a warning if the new subgoal has type variables;
  4933 
  4934 * removed old README and Makefiles;
  4935 
  4936 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4937 
  4938 * removed obsolete init_pps and init_database;
  4939 
  4940 * deleted the obsolete tactical STATE, which was declared by
  4941     fun STATE tacfun st = tacfun st st;
  4942 
  4943 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4944 (which abbreviates $HOME);
  4945 
  4946 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4947 use isatool fixseq to adapt your ML programs (this works for fully
  4948 qualified references to the Sequence structure only!);
  4949 
  4950 * use_thy no longer requires writable current directory; it always
  4951 reloads .ML *and* .thy file, if either one is out of date;
  4952 
  4953 
  4954 *** Classical Reasoner ***
  4955 
  4956 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4957 tactics that use classical reasoning to simplify a subgoal without
  4958 splitting it into several subgoals;
  4959 
  4960 * Safe_tac: like safe_tac but uses the default claset;
  4961 
  4962 
  4963 *** Simplifier ***
  4964 
  4965 * added simplification meta rules:
  4966     (asm_)(full_)simplify: simpset -> thm -> thm;
  4967 
  4968 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4969 logics (again);
  4970 
  4971 * added prems argument to simplification procedures;
  4972 
  4973 * HOL, FOL, ZF: added infix function `addsplits':
  4974   instead of `<simpset> setloop (split_tac <thms>)'
  4975   you can simply write `<simpset> addsplits <thms>'
  4976 
  4977 
  4978 *** Syntax ***
  4979 
  4980 * TYPE('a) syntax for type reflection terms;
  4981 
  4982 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4983 
  4984 * pretty printer: changed order of mixfix annotation preference (again!);
  4985 
  4986 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4987 
  4988 
  4989 *** HOL ***
  4990 
  4991 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4992   with `addloop' of the simplifier to faciliate case splitting in premises.
  4993 
  4994 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4995 
  4996 * HOL/Auth: new protocol proofs including some for the Internet
  4997   protocol TLS;
  4998 
  4999 * HOL/Map: new theory of `maps' a la VDM;
  5000 
  5001 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5002 cancelling out common nat summands from =, <, <= (in)equalities, or
  5003 differences; simplification procedures nat_cancel_factor for
  5004 cancelling common factor from =, <, <= (in)equalities over natural
  5005 sums; nat_cancel contains both kinds of procedures, it is installed by
  5006 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5007 
  5008 * HOL/simplifier: terms of the form
  5009   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5010   are rewritten to
  5011   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5012   and those of the form
  5013   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5014   are rewritten to
  5015   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5016 
  5017 * HOL/datatype
  5018   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5019 
  5020   P(t_case f1 ... fn x) =
  5021      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5022         ...
  5023        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5024      )
  5025 
  5026   and a theorem `split_t_case_asm' of the form
  5027 
  5028   P(t_case f1 ... fn x) =
  5029     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5030         ...
  5031        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5032      )
  5033   which can be added to a simpset via `addsplits'. The existing theorems
  5034   expand_list_case and expand_option_case have been renamed to
  5035   split_list_case and split_option_case.
  5036 
  5037 * HOL/Arithmetic:
  5038   - `pred n' is automatically converted to `n-1'.
  5039     Users are strongly encouraged not to use `pred' any longer,
  5040     because it will disappear altogether at some point.
  5041   - Users are strongly encouraged to write "0 < n" rather than
  5042     "n ~= 0". Theorems and proof tools have been modified towards this
  5043     `standard'.
  5044 
  5045 * HOL/Lists:
  5046   the function "set_of_list" has been renamed "set" (and its theorems too);
  5047   the function "nth" now takes its arguments in the reverse order and
  5048   has acquired the infix notation "!" as in "xs!n".
  5049 
  5050 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5051 
  5052 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5053   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5054 
  5055 * HOL/record: extensible records with schematic structural subtyping
  5056 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5057 still lacks various theorems and concrete record syntax;
  5058 
  5059 
  5060 *** HOLCF ***
  5061 
  5062 * removed "axioms" and "generated by" sections;
  5063 
  5064 * replaced "ops" section by extended "consts" section, which is capable of
  5065   handling the continuous function space "->" directly;
  5066 
  5067 * domain package:
  5068   . proves theorems immediately and stores them in the theory,
  5069   . creates hierachical name space,
  5070   . now uses normal mixfix annotations (instead of cinfix...),
  5071   . minor changes to some names and values (for consistency),
  5072   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5073   . separator between mutual domain defs: changed "," to "and",
  5074   . improved handling of sort constraints;  now they have to
  5075     appear on the left-hand side of the equations only;
  5076 
  5077 * fixed LAM <x,y,zs>.b syntax;
  5078 
  5079 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5080 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5081 
  5082 
  5083 *** FOL and ZF ***
  5084 
  5085 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5086   with `addloop' of the simplifier to faciliate case splitting in premises.
  5087 
  5088 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5089 in HOL, they strip ALL and --> from proved theorems;
  5090 
  5091 
  5092 
  5093 New in Isabelle94-8 (May 1997)
  5094 ------------------------------
  5095 
  5096 *** General Changes ***
  5097 
  5098 * new utilities to build / run / maintain Isabelle etc. (in parts
  5099 still somewhat experimental); old Makefiles etc. still functional;
  5100 
  5101 * new 'Isabelle System Manual';
  5102 
  5103 * INSTALL text, together with ./configure and ./build scripts;
  5104 
  5105 * reimplemented type inference for greater efficiency, better error
  5106 messages and clean internal interface;
  5107 
  5108 * prlim command for dealing with lots of subgoals (an easier way of
  5109 setting goals_limit);
  5110 
  5111 
  5112 *** Syntax ***
  5113 
  5114 * supports alternative (named) syntax tables (parser and pretty
  5115 printer); internal interface is provided by add_modesyntax(_i);
  5116 
  5117 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5118 be used in conjunction with the Isabelle symbol font; uses the
  5119 "symbols" syntax table;
  5120 
  5121 * added token_translation interface (may translate name tokens in
  5122 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5123 the current print_mode); IMPORTANT: user print translation functions
  5124 are responsible for marking newly introduced bounds
  5125 (Syntax.mark_boundT);
  5126 
  5127 * token translations for modes "xterm" and "xterm_color" that display
  5128 names in bold, underline etc. or colors (which requires a color
  5129 version of xterm);
  5130 
  5131 * infixes may now be declared with names independent of their syntax;
  5132 
  5133 * added typed_print_translation (like print_translation, but may
  5134 access type of constant);
  5135 
  5136 
  5137 *** Classical Reasoner ***
  5138 
  5139 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5140 some limitations.  Blast_tac...
  5141   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5142   + ignores elimination rules that don't have the correct format
  5143         (the conclusion MUST be a formula variable)
  5144   + ignores types, which can make HOL proofs fail
  5145   + rules must not require higher-order unification, e.g. apply_type in ZF
  5146     [message "Function Var's argument not a bound variable" relates to this]
  5147   + its proof strategy is more general but can actually be slower
  5148 
  5149 * substitution with equality assumptions no longer permutes other
  5150 assumptions;
  5151 
  5152 * minor changes in semantics of addafter (now called addaltern); renamed
  5153 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5154 (and access functions for it);
  5155 
  5156 * improved combination of classical reasoner and simplifier:
  5157   + functions for handling clasimpsets
  5158   + improvement of addss: now the simplifier is called _after_ the
  5159     safe steps.
  5160   + safe variant of addss called addSss: uses safe simplifications
  5161     _during_ the safe steps. It is more complete as it allows multiple
  5162     instantiations of unknowns (e.g. with slow_tac).
  5163 
  5164 *** Simplifier ***
  5165 
  5166 * added interface for simplification procedures (functions that
  5167 produce *proven* rewrite rules on the fly, depending on current
  5168 redex);
  5169 
  5170 * ordering on terms as parameter (used for ordered rewriting);
  5171 
  5172 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5173 
  5174 * the solver is now split into a safe and an unsafe part.
  5175 This should be invisible for the normal user, except that the
  5176 functions setsolver and addsolver have been renamed to setSolver and
  5177 addSolver; added safe_asm_full_simp_tac;
  5178 
  5179 
  5180 *** HOL ***
  5181 
  5182 * a generic induction tactic `induct_tac' which works for all datatypes and
  5183 also for type `nat';
  5184 
  5185 * a generic case distinction tactic `exhaust_tac' which works for all
  5186 datatypes and also for type `nat';
  5187 
  5188 * each datatype comes with a function `size';
  5189 
  5190 * patterns in case expressions allow tuple patterns as arguments to
  5191 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5192 
  5193 * primrec now also works with type nat;
  5194 
  5195 * recdef: a new declaration form, allows general recursive functions to be
  5196 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5197 
  5198 * the constant for negation has been renamed from "not" to "Not" to
  5199 harmonize with FOL, ZF, LK, etc.;
  5200 
  5201 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5202 infinite lists;
  5203 
  5204 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5205 
  5206 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5207 problems in commutative rings, using axiomatic type classes for + and *;
  5208 
  5209 * more examples in HOL/MiniML and HOL/Auth;
  5210 
  5211 * more default rewrite rules for quantifiers, union/intersection;
  5212 
  5213 * a new constant `arbitrary == @x.False';
  5214 
  5215 * HOLCF/IOA replaces old HOL/IOA;
  5216 
  5217 * HOLCF changes: derived all rules and arities
  5218   + axiomatic type classes instead of classes
  5219   + typedef instead of faking type definitions
  5220   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5221   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5222   + eliminated the types void, one, tr
  5223   + use unit lift and bool lift (with translations) instead of one and tr
  5224   + eliminated blift from Lift3.thy (use Def instead of blift)
  5225   all eliminated rules are derived as theorems --> no visible changes ;
  5226 
  5227 
  5228 *** ZF ***
  5229 
  5230 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5231 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5232 as ZF_cs addSIs [equalityI];
  5233 
  5234 
  5235 
  5236 New in Isabelle94-7 (November 96)
  5237 ---------------------------------
  5238 
  5239 * allowing negative levels (as offsets) in prlev and choplev;
  5240 
  5241 * super-linear speedup for large simplifications;
  5242 
  5243 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5244 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5245 FAIL); can suppress it using the command Delsimps (ex_simps @
  5246 all_simps); De Morgan laws are also now included, by default;
  5247 
  5248 * improved printing of ==>  :  ~:
  5249 
  5250 * new object-logic "Sequents" adds linear logic, while replacing LK
  5251 and Modal (thanks to Sara Kalvala);
  5252 
  5253 * HOL/Auth: correctness proofs for authentication protocols;
  5254 
  5255 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5256 examples on HOL/Auth);
  5257 
  5258 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5259 the rewriter and classical reasoner simultaneously;
  5260 
  5261 * function uresult no longer returns theorems in "standard" format;
  5262 regain previous version by: val uresult = standard o uresult;
  5263 
  5264 
  5265 
  5266 New in Isabelle94-6
  5267 -------------------
  5268 
  5269 * oracles -- these establish an interface between Isabelle and trusted
  5270 external reasoners, which may deliver results as theorems;
  5271 
  5272 * proof objects (in particular record all uses of oracles);
  5273 
  5274 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5275 
  5276 * "constdefs" section in theory files;
  5277 
  5278 * "primrec" section (HOL) no longer requires names;
  5279 
  5280 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5281 
  5282 
  5283 
  5284 New in Isabelle94-5
  5285 -------------------
  5286 
  5287 * reduced space requirements;
  5288 
  5289 * automatic HTML generation from theories;
  5290 
  5291 * theory files no longer require "..." (quotes) around most types;
  5292 
  5293 * new examples, including two proofs of the Church-Rosser theorem;
  5294 
  5295 * non-curried (1994) version of HOL is no longer distributed;
  5296 
  5297 
  5298 
  5299 New in Isabelle94-4
  5300 -------------------
  5301 
  5302 * greatly reduced space requirements;
  5303 
  5304 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5305 
  5306 * searchable theorem database (see the section "Retrieving theorems" on
  5307 page 8 of the Reference Manual);
  5308 
  5309 * new examples, including Grabczewski's monumental case study of the
  5310 Axiom of Choice;
  5311 
  5312 * The previous version of HOL renamed to Old_HOL;
  5313 
  5314 * The new version of HOL (previously called CHOL) uses a curried syntax
  5315 for functions.  Application looks like f a b instead of f(a,b);
  5316 
  5317 * Mutually recursive inductive definitions finally work in HOL;
  5318 
  5319 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5320 translates to the operator "split";
  5321 
  5322 
  5323 
  5324 New in Isabelle94-3
  5325 -------------------
  5326 
  5327 * new infix operator, addss, allowing the classical reasoner to
  5328 perform simplification at each step of its search.  Example:
  5329         fast_tac (cs addss ss)
  5330 
  5331 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5332 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5333 look like (a,b) instead of <a,b>;
  5334 
  5335 * PLEASE NOTE: CHOL will eventually replace HOL!
  5336 
  5337 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5338 It translates to the operator "split".  A new theory of integers is available;
  5339 
  5340 * In ZF, integer numerals now denote two's-complement binary integers.
  5341 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5342 
  5343 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5344 of the Axiom of Choice;
  5345 
  5346 
  5347 
  5348 New in Isabelle94-2
  5349 -------------------
  5350 
  5351 * Significantly faster resolution;
  5352 
  5353 * the different sections in a .thy file can now be mixed and repeated
  5354 freely;
  5355 
  5356 * Database of theorems for FOL, HOL and ZF.  New
  5357 commands including qed, qed_goal and bind_thm store theorems in the database.
  5358 
  5359 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5360 a given theory (thms_of), or find out what theory a theorem was proved in
  5361 (theory_of_thm);
  5362 
  5363 * Bugs fixed in the inductive definition and datatype packages;
  5364 
  5365 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5366 and HOL_dup_cs obsolete;
  5367 
  5368 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5369 have been removed;
  5370 
  5371 * Simpler definition of function space in ZF;
  5372 
  5373 * new results about cardinal and ordinal arithmetic in ZF;
  5374 
  5375 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5376 types;
  5377 
  5378 :mode=text:wrap=hard:maxLineLen=72:
  5379 
  5380 $Id$