NEWS
author wenzelm
Mon Sep 22 15:26:11 2008 +0200 (2008-09-22)
changeset 28317 83c4fc383409
parent 28294 3ba048423a99
child 28350 715163ec93c0
permissions -rw-r--r--
added reject_draft;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * The Isabelle System Manual (system) has been updated, with formally
    10 checked references as hyperlinks.
    11 
    12 * Generalized Isar history, with support for linear undo, direct state
    13 addressing etc.
    14 
    15 * Recovered hiding of consts, which was accidentally broken in
    16 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
    17 makes c inaccessible; consider using ``hide (open) const c'' instead.
    18 
    19 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
    20 interface instead.
    21 
    22 
    23 *** Pure ***
    24 
    25 * Changed defaults for unify configuration options:
    26 
    27   unify_trace_bound = 50 (formerly 25)
    28   unify_search_bound = 60 (formerly 30)
    29 
    30 * Different bookkeeping for code equations:
    31   a) On theory merge, the last set of code equations for a particular constant
    32      is taken (in accordance with the policy applied by other parts of the
    33      code generator framework).
    34   b) Code equations stemming from explicit declarations (e.g. code attribute)
    35      gain priority over default code equations stemming from definition, primrec,
    36      fun etc.
    37   INCOMPATIBILITY.
    38 
    39 * Global versions of theorems stemming from classes do not carry
    40 a parameter prefix any longer.  INCOMPATIBILITY.
    41 
    42 * Dropped "locale (open)".  INCOMPATBILITY.
    43 
    44 * Interpretation commands no longer attempt to simplify goal.
    45 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
    46 methods intro_locales and unfold_locales to clarify.
    47 
    48 * Interpretation commands no longer accept interpretation attributes.
    49 INCOMPATBILITY.
    50 
    51 * Command 'instance': attached definitions no longer accepted.
    52 INCOMPATIBILITY, use proper 'instantiation' target.
    53 
    54 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
    55 
    56 * The 'axiomatization' command now only works within a global theory
    57 context.  INCOMPATIBILITY.
    58 
    59 
    60 *** Document preparation ***
    61 
    62 * Antiquotation @{lemma} now imitates a regular terminal proof,
    63 demanding keyword 'by' and supporting the full method expression
    64 syntax just like the Isar command 'by'.
    65 
    66 
    67 *** HOL ***
    68 
    69 * HOL/Main: command "value" now integrates different evaluation
    70 mechanisms.  The result of the first successful evaluation mechanism
    71 is printed.  In square brackets a particular named evaluation
    72 mechanisms may be specified (currently, [SML], [code] or [nbe]).  See
    73 further src/HOL/ex/Eval_Examples.thy.
    74 
    75 * HOL/Orderings: class "wellorder" moved here, with explicit induction
    76 rule "less_induct" as assumption.  For instantiation of "wellorder" by
    77 means of predicate "wf", use rule wf_wellorderI.  INCOMPATIBILITY.
    78 
    79 * HOL/Orderings: added class "preorder" as superclass of "order".
    80 INCOMPATIBILITY: Instantiation proofs for order, linorder
    81 etc. slightly changed.  Some theorems named order_class.* now named
    82 preorder_class.*.
    83 
    84 * HOL/Ring_and_Field and HOL/Divides: Definition of "op dvd" has been
    85 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
    86 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
    87 of lemmas from Divides has been generalized from nat to class
    88 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
    89 renames resulting from duplicate elimination:
    90 
    91     dvd_def_mod ~>          dvd_eq_mod_eq_0
    92     zero_dvd_iff ~>         dvd_0_left_iff
    93     DIVISION_BY_ZERO_DIV ~> div_by_0
    94     DIVISION_BY_ZERO_MOD ~> mod_by_0
    95     mult_div ~>             div_mult_self2_is_id
    96     mult_mod ~>             mod_mult_self2_is_0
    97 
    98 * HOL/Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
    99 zlcm (for int); carried together from various gcd/lcm developements in
   100 the HOL Distribution.  zgcd and zlcm replace former igcd and ilcm;
   101 corresponding theorems renamed accordingly.  INCOMPATIBILY.  To
   102 recover tupled syntax, use syntax declarations like:
   103 
   104     hide (open) const gcd
   105     abbreviation gcd where
   106       "gcd == (%(a, b). GCD.gcd a b)"
   107     notation (output)
   108       GCD.gcd ("gcd '(_, _')")
   109 
   110 (analogously for lcm, zgcd, zlcm).
   111 
   112 * HOL/Real/Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   113 
   114 * New ML antiquotation @{code}: takes constant as argument, generates
   115 corresponding code in background and inserts name of the corresponding
   116 resulting ML value/function/datatype constructor binding in place.
   117 All occurrences of @{code} with a single ML block are generated
   118 simultaneously.  Provides a generic and safe interface for
   119 instrumentalizing code generation.  See HOL/ex/Code_Antiq for a toy
   120 example, or HOL/Complex/ex/ReflectedFerrack for a more ambitious
   121 application.  In future you ought refrain from ad-hoc compiling
   122 generated SML code on the ML toplevel.  Note that (for technical
   123 reasons) @{code} cannot refer to constants for which user-defined
   124 serializations are set.  Refer to the corresponding ML counterpart
   125 directly in that cases.
   126 
   127 * Integrated image HOL-Complex with HOL.  Entry points Main.thy and
   128 Complex_Main.thy remain as they are.
   129 
   130 * New image HOL-Plain provides a minimal HOL with the most important
   131 tools available (inductive, datatype, primrec, ...).  By convention
   132 the corresponding theory Plain should be ancestor of every further
   133 (library) theory.  Some library theories now have ancestor Plain
   134 (instead of Main), thus theory Main occasionally has to be imported
   135 explicitly.
   136 
   137 * The metis method now fails in the usual manner, rather than raising
   138 an exception, if it determines that it cannot prove the theorem.
   139 
   140 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   141 as the structured Isar versions "cases" and "induct", cf. the
   142 corresponding "cases" and "induct" attributes.  Mutual induction rules
   143 are now presented as a list of individual projections
   144 (e.g. foo_bar.inducts for types foo and bar); the old format with
   145 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   146 rare situations a different rule is selected --- notably nested tuple
   147 elimination instead of former prod.exhaust: use explicit (case_tac t
   148 rule: prod.exhaust) here.
   149 
   150 * Attributes "cases", "induct", "coinduct" support "del" option.
   151 
   152 * Removed fact "case_split_thm", which duplicates "case_split".
   153 
   154 * Command 'rep_datatype': instead of theorem names the command now
   155 takes a list of terms denoting the constructors of the type to be
   156 represented as datatype.  The characteristic theorems have to be
   157 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   158 have disappeared in favour of existing ones:
   159 
   160     unit_induct                 ~> unit.induct
   161     prod_induct                 ~> prod.induct
   162     sum_induct                  ~> sum.induct
   163     Suc_Suc_eq                  ~> nat.inject
   164     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   165 
   166 * Library/Nat_Infinity: added addition, numeral syntax and more
   167 instantiations for algebraic structures.  Removed some duplicate
   168 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   169 
   170 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   171 menu.
   172 
   173 
   174 *** HOL-Algebra ***
   175 
   176 * New locales for orders and lattices where the equivalence relation
   177   is not restricted to equality.  INCOMPATIBILITY: all order and
   178   lattice locales use a record structure with field eq for the
   179   equivalence.
   180 
   181 * New theory of factorial domains.
   182 
   183 * Units_l_inv and Units_r_inv are now simprules by default.
   184 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   185 and/or r_inv will now also require deletion of these lemmas.
   186 
   187 * Renamed the following theorems.  INCOMPATIBILITY.
   188 UpperD ~> Upper_memD
   189 LowerD ~> Lower_memD
   190 least_carrier ~> least_closed
   191 greatest_carrier ~> greatest_closed
   192 greatest_Lower_above ~> greatest_Lower_below
   193 one_zero ~> carrier_one_zero
   194 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   195 
   196 
   197 *** HOL-NSA ***
   198 
   199 * Created new image HOL-NSA, containing theories of nonstandard
   200 analysis which were previously part of HOL-Complex.  Entry point
   201 Hyperreal.thy remains valid, but theories formerly using
   202 Complex_Main.thy should now use new entry point Hypercomplex.thy.
   203 
   204 
   205 *** ZF ***
   206 
   207 * Proof of Zorn's Lemma for partial orders.
   208 
   209 
   210 *** ML ***
   211 
   212 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   213 to 'a -> thm, while results are always tagged with an authentic oracle
   214 name.  The Isar command 'oracle' is now polymorphic, no argument type
   215 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   216 accordingly.  Note that extra performance may be gained by producing
   217 the cterm carefully, avoiding slow Thm.cterm_of.
   218 
   219 * ML bindings produced via Isar commands are stored within the Isar
   220 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   221 become thread-safe and work with undo as expected (concerning
   222 top-level bindings, not side-effects on global references).
   223 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   224 compiler at runtime; really global bindings need to be given outside a
   225 theory. [Poly/ML 5.2 or later]
   226 
   227 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   228 context. Top-level ML bindings are stored within the proof context in
   229 a purely sequential fashion, disregarding the nested proof structure.
   230 ML bindings introduced by 'ML_prf' are discarded at the end of the
   231 proof.  [Poly/ML 5.2 or later]
   232 
   233 * Generic Toplevel.add_hook interface allows to analyze the result of
   234 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   235 for theorem dependency output of transactions resulting in a new
   236 theory state.
   237 
   238 * Name bindings in higher specification mechanisms (notably
   239 LocalTheory.define, LocalTheory.note, and derived packages) are now
   240 formalized as type Name.binding, replacing old bstring.
   241 INCOMPATIBILITY, need to wrap strings via Name.binding function, see
   242 also Name.name_of.  Packages should pass name bindings given by the
   243 user to underlying specification mechanisms; this enables precise
   244 tracking of source positions, for example.
   245 
   246 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   247 LocalTheory.note etc.) now refer to the *full* internal name, not the
   248 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   249 
   250 * Rules and tactics that read instantiations (read_instantiate,
   251 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   252 context, which is required for parsing and type-checking.  Moreover,
   253 the variables are specified as plain indexnames, not string encodings
   254 thereof.  INCOMPATIBILITY.
   255 
   256 * Disposed old type and term read functions (Sign.read_def_typ,
   257 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   258 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   259 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   260 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   261 resort for legacy applications.
   262 
   263 * Antiquotations: block-structured compilation context indicated by
   264 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   265 
   266   @{let ?pat = term}                      - term abbreviation (HO matching)
   267   @{note name = fact}                     - fact abbreviation
   268   @{thm fact}                             - singleton fact (with attributes)
   269   @{thms fact}                            - general fact (with attributes)
   270   @{lemma prop by method}                 - singleton goal
   271   @{lemma prop by meth1 meth2}            - singleton goal
   272   @{lemma prop1 ... propN by method}      - general goal
   273   @{lemma prop1 ... propN by meth1 meth2} - general goal
   274   @{lemma (open) ...}                     - open derivation
   275 
   276 
   277 *** System ***
   278 
   279 * Multithreading for Poly/ML 5.1 is no longer supported, only for
   280 Poly/ML 5.2 or later.
   281 
   282 * The Isabelle "emacs" tool provides a specific interface to invoke
   283 Proof General / Emacs, with more explicit failure if that is not
   284 installed (the old isabelle-interface script silently falls back on
   285 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   286 installation location of the Proof General distribution.
   287 
   288 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   289 the Isabelle process into a JVM/Scala application.  See
   290 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   291 process wrapper has been discontinued.)
   292 
   293 * Status messages (with exact source position information) are
   294 emitted, if proper markup print mode is enabled.  This allows
   295 user-interface components to provide detailed feedback on internal
   296 prover operations.
   297 
   298 * Homegrown Isabelle font with unicode layout, see Isabelle/lib/fonts.
   299 
   300 
   301 
   302 New in Isabelle2008 (June 2008)
   303 -------------------------------
   304 
   305 *** General ***
   306 
   307 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   308 and updated, with formally checked references as hyperlinks.
   309 
   310 * Theory loader: use_thy (and similar operations) no longer set the
   311 implicit ML context, which was occasionally hard to predict and in
   312 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   313 provides a proper context already.
   314 
   315 * Theory loader: old-style ML proof scripts being *attached* to a thy
   316 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   317 'use' within a theory file will do the job.
   318 
   319 * Name space merge now observes canonical order, i.e. the second space
   320 is inserted into the first one, while existing entries in the first
   321 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   322 swap theory imports.
   323 
   324 * Syntax: symbol \<chi> is now considered a letter.  Potential
   325 INCOMPATIBILITY in identifier syntax etc.
   326 
   327 * Outer syntax: string tokens no longer admit escaped white space,
   328 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   329 white space without escapes.
   330 
   331 * Outer syntax: string tokens may contain arbitrary character codes
   332 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   333 "foo_bar".
   334 
   335 
   336 *** Pure ***
   337 
   338 * Context-dependent token translations.  Default setup reverts locally
   339 fixed variables, and adds hilite markup for undeclared frees.
   340 
   341 * Unused theorems can be found using the new command 'unused_thms'.
   342 There are three ways of invoking it:
   343 
   344 (1) unused_thms
   345      Only finds unused theorems in the current theory.
   346 
   347 (2) unused_thms thy_1 ... thy_n -
   348      Finds unused theorems in the current theory and all of its ancestors,
   349      excluding the theories thy_1 ... thy_n and all of their ancestors.
   350 
   351 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   352      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   353      their ancestors, excluding the theories thy_1 ... thy_n and all of
   354      their ancestors.
   355 
   356 In order to increase the readability of the list produced by
   357 unused_thms, theorems that have been created by a particular instance
   358 of a theory command such as 'inductive' or 'function' are considered
   359 to belong to the same "group", meaning that if at least one theorem in
   360 this group is used, the other theorems in the same group are no longer
   361 reported as unused.  Moreover, if all theorems in the group are
   362 unused, only one theorem in the group is displayed.
   363 
   364 Note that proof objects have to be switched on in order for
   365 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   366 usually the case when using Proof General with the default settings).
   367 
   368 * Authentic naming of facts disallows ad-hoc overwriting of previous
   369 theorems within the same name space.  INCOMPATIBILITY, need to remove
   370 duplicate fact bindings, or even accidental fact duplications.  Note
   371 that tools may maintain dynamically scoped facts systematically, using
   372 PureThy.add_thms_dynamic.
   373 
   374 * Command 'hide' now allows to hide from "fact" name space as well.
   375 
   376 * Eliminated destructive theorem database, simpset, claset, and
   377 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   378 update of theories within ML code.
   379 
   380 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   381 INCOMPATIBILITY, object-logics depending on former Pure require
   382 additional setup PureThy.old_appl_syntax_setup; object-logics
   383 depending on former CPure need to refer to Pure.
   384 
   385 * Commands 'use' and 'ML' are now purely functional, operating on
   386 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   387 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   388 INCOMPATIBILITY.
   389 
   390 * Command 'setup': discontinued implicit version with ML reference.
   391 
   392 * Instantiation target allows for simultaneous specification of class
   393 instance operations together with an instantiation proof.
   394 Type-checking phase allows to refer to class operations uniformly.
   395 See src/HOL/Complex/Complex.thy for an Isar example and
   396 src/HOL/Library/Eval.thy for an ML example.
   397 
   398 * Indexing of literal facts: be more serious about including only
   399 facts from the visible specification/proof context, but not the
   400 background context (locale etc.).  Affects `prop` notation and method
   401 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   402 situations.
   403 
   404 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   405 "(open)" option, which used to expose internal bound variables to the
   406 proof text.
   407 
   408 * Isar statements: removed obsolete case "rule_context".
   409 INCOMPATIBILITY, better use explicit fixes/assumes.
   410 
   411 * Locale proofs: default proof step now includes 'unfold_locales';
   412 hence 'proof' without argument may be used to unfold locale
   413 predicates.
   414 
   415 
   416 *** Document preparation ***
   417 
   418 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   419 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   420 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   421 spot); renamed link color from "darkblue" to "linkcolor" (default
   422 value unchanged, can be redefined via \definecolor); no longer sets
   423 "a4paper" option (unnecessary or even intrusive).
   424 
   425 * Antiquotation @{lemma A method} proves proposition A by the given
   426 method (either a method name or a method name plus (optional) method
   427 arguments in parentheses) and prints A just like @{prop A}.
   428 
   429 
   430 *** HOL ***
   431 
   432 * New primrec package.  Specification syntax conforms in style to
   433 definition/function/....  No separate induction rule is provided.  The
   434 "primrec" command distinguishes old-style and new-style specifications
   435 by syntax.  The former primrec package is now named OldPrimrecPackage.
   436 When adjusting theories, beware: constants stemming from new-style
   437 primrec specifications have authentic syntax.
   438 
   439 * Metis prover is now an order of magnitude faster, and also works
   440 with multithreading.
   441 
   442 * Metis: the maximum number of clauses that can be produced from a
   443 theorem is now given by the attribute max_clauses.  Theorems that
   444 exceed this number are ignored, with a warning printed.
   445 
   446 * Sledgehammer no longer produces structured proofs by default. To
   447 enable, declare [[sledgehammer_full = true]].  Attributes
   448 reconstruction_modulus, reconstruction_sorts renamed
   449 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   450 
   451 * Method "induct_scheme" derives user-specified induction rules
   452 from well-founded induction and completeness of patterns. This factors
   453 out some operations that are done internally by the function package
   454 and makes them available separately.  See
   455 src/HOL/ex/Induction_Scheme.thy for examples.
   456 
   457 * More flexible generation of measure functions for termination
   458 proofs: Measure functions can be declared by proving a rule of the
   459 form "is_measure f" and giving it the [measure_function] attribute.
   460 The "is_measure" predicate is logically meaningless (always true), and
   461 just guides the heuristic.  To find suitable measure functions, the
   462 termination prover sets up the goal "is_measure ?f" of the appropriate
   463 type and generates all solutions by prolog-style backwards proof using
   464 the declared rules.
   465 
   466 This setup also deals with rules like 
   467 
   468   "is_measure f ==> is_measure (list_size f)"
   469 
   470 which accommodates nested datatypes that recurse through lists.
   471 Similar rules are predeclared for products and option types.
   472 
   473 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   474 
   475   INCOMPATIBILITIES:
   476 
   477   - Definitions of overloaded constants on sets have to be replaced by
   478     definitions on => and bool.
   479 
   480   - Some definitions of overloaded operators on sets can now be proved
   481     using the definitions of the operators on => and bool.  Therefore,
   482     the following theorems have been renamed:
   483 
   484       subset_def   -> subset_eq
   485       psubset_def  -> psubset_eq
   486       set_diff_def -> set_diff_eq
   487       Compl_def    -> Compl_eq
   488       Sup_set_def  -> Sup_set_eq
   489       Inf_set_def  -> Inf_set_eq
   490       sup_set_def  -> sup_set_eq
   491       inf_set_def  -> inf_set_eq
   492 
   493   - Due to the incompleteness of the HO unification algorithm, some
   494     rules such as subst may require manual instantiation, if some of
   495     the unknowns in the rule is a set.
   496 
   497   - Higher order unification and forward proofs:
   498     The proof pattern
   499 
   500       have "P (S::'a set)" <...>
   501       then have "EX S. P S" ..
   502 
   503     no longer works (due to the incompleteness of the HO unification
   504     algorithm) and must be replaced by the pattern
   505 
   506       have "EX S. P S"
   507       proof
   508         show "P S" <...>
   509       qed
   510 
   511   - Calculational reasoning with subst (or similar rules):
   512     The proof pattern
   513 
   514       have "P (S::'a set)" <...>
   515       also have "S = T" <...>
   516       finally have "P T" .
   517 
   518     no longer works (for similar reasons as the previous example) and
   519     must be replaced by something like
   520 
   521       have "P (S::'a set)" <...>
   522       moreover have "S = T" <...>
   523       ultimately have "P T" by simp
   524 
   525   - Tactics or packages written in ML code:
   526     Code performing pattern matching on types via
   527 
   528       Type ("set", [T]) => ...
   529 
   530     must be rewritten. Moreover, functions like strip_type or
   531     binder_types no longer return the right value when applied to a
   532     type of the form
   533 
   534       T1 => ... => Tn => U => bool
   535 
   536     rather than
   537 
   538       T1 => ... => Tn => U set
   539 
   540 * Merged theories Wellfounded_Recursion, Accessible_Part and
   541 Wellfounded_Relations to theory Wellfounded.
   542 
   543 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   544 
   545 * Class finite no longer treats UNIV as class parameter.  Use class
   546 enum from theory Library/Enum instead to achieve a similar effect.
   547 INCOMPATIBILITY.
   548 
   549 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   550 and "Cons".  INCOMPATIBILITY.
   551 
   552 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   553 Potential INCOMPATIBILITY.
   554 
   555 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   556 injective_fst_snd removed, use split_eta and prod_eqI instead.
   557 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   558 
   559 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   560 the same name in theory Orderings:
   561 
   562   less_trans
   563   less_linear
   564   le_imp_less_or_eq
   565   le_less_trans
   566   less_le_trans
   567   less_not_sym
   568   less_asym
   569 
   570 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   571 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   572 and different variable names.
   573 
   574 * Library/Option_ord.thy: Canonical order on option type.
   575 
   576 * Library/RBT.thy: Red-black trees, an efficient implementation of
   577 finite maps.
   578 
   579 * Library/Countable.thy: Type class for countable types.
   580 
   581 * Theory Int: The representation of numerals has changed.  The infix
   582 operator BIT and the bit datatype with constructors B0 and B1 have
   583 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   584 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   585 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   586 accordingly.
   587 
   588 * Theory Nat: definition of <= and < on natural numbers no longer
   589 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   590 le_def and less_def have disappeared.  Consider lemmas not_less
   591 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   592 
   593 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   594 (whose purpose mainly is for various fold_set functionals) have been
   595 abandoned in favor of the existing algebraic classes
   596 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   597 lower_semilattice (resp. upper_semilattice) and linorder.
   598 INCOMPATIBILITY.
   599 
   600 * Theory Transitive_Closure: induct and cases rules now declare proper
   601 case_names ("base" and "step").  INCOMPATIBILITY.
   602 
   603 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   604 lattices.  The form set-specific version is available as
   605 Inductive.lfp_ordinal_induct_set.
   606 
   607 * Renamed theorems "power.simps" to "power_int.simps".
   608 INCOMPATIBILITY.
   609 
   610 * Class semiring_div provides basic abstract properties of semirings
   611 with division and modulo operations.  Subsumes former class dvd_mod.
   612 
   613 * Merged theories IntDef, Numeral and IntArith into unified theory
   614 Int.  INCOMPATIBILITY.
   615 
   616 * Theory Library/Code_Index: type "index" now represents natural
   617 numbers rather than integers.  INCOMPATIBILITY.
   618 
   619 * New class "uminus" with operation "uminus" (split of from class
   620 "minus" which now only has operation "minus", binary).
   621 INCOMPATIBILITY.
   622 
   623 * Constants "card", "internal_split", "option_map" now with authentic
   624 syntax.  INCOMPATIBILITY.
   625 
   626 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   627 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   628 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   629 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   630 Sup_set_def, le_def, less_def, option_map_def now with object
   631 equality.  INCOMPATIBILITY.
   632 
   633 * Records. Removed K_record, and replaced it by pure lambda term
   634 %x. c. The simplifier setup is now more robust against eta expansion.
   635 INCOMPATIBILITY: in cases explicitly referring to K_record.
   636 
   637 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   638 
   639 * Library/ListVector: new theory of arithmetic vector operations.
   640 
   641 * Library/Order_Relation: new theory of various orderings as sets of
   642 pairs.  Defines preorders, partial orders, linear orders and
   643 well-orders on sets and on types.
   644 
   645 
   646 *** ZF ***
   647 
   648 * Renamed some theories to allow to loading both ZF and HOL in the
   649 same session:
   650 
   651   Datatype  -> Datatype_ZF
   652   Inductive -> Inductive_ZF
   653   Int       -> Int_ZF
   654   IntDiv    -> IntDiv_ZF
   655   Nat       -> Nat_ZF
   656   List      -> List_ZF
   657   Main      -> Main_ZF
   658 
   659 INCOMPATIBILITY: ZF theories that import individual theories below
   660 Main might need to be adapted.  Regular theory Main is still
   661 available, as trivial extension of Main_ZF.
   662 
   663 
   664 *** ML ***
   665 
   666 * ML within Isar: antiquotation @{const name} or @{const
   667 name(typargs)} produces statically-checked Const term.
   668 
   669 * Functor NamedThmsFun: data is available to the user as dynamic fact
   670 (of the same name).  Removed obsolete print command.
   671 
   672 * Removed obsolete "use_legacy_bindings" function.
   673 
   674 * The ``print mode'' is now a thread-local value derived from a global
   675 template (the former print_mode reference), thus access becomes
   676 non-critical.  The global print_mode reference is for session
   677 management only; user-code should use print_mode_value,
   678 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   679 
   680 * Functions system/system_out provide a robust way to invoke external
   681 shell commands, with propagation of interrupts (requires Poly/ML 5.2).
   682 Do not use OS.Process.system etc. from the basis library!
   683 
   684 
   685 *** System ***
   686 
   687 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   688 in accordance with Proof General 3.7, which prefers GNU emacs.
   689 
   690 * isatool tty runs Isabelle process with plain tty interaction;
   691 optional line editor may be specified via ISABELLE_LINE_EDITOR
   692 setting, the default settings attempt to locate "ledit" and "rlwrap".
   693 
   694 * isatool browser now works with Cygwin as well, using general
   695 "javapath" function defined in Isabelle process environment.
   696 
   697 * YXML notation provides a simple and efficient alternative to
   698 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   699 isatool yxml as described in the Isabelle system manual.
   700 
   701 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   702 provides general wrapper for managing an Isabelle process in a robust
   703 fashion, with ``cooked'' output from stdin/stderr.
   704 
   705 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   706 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   707 
   708 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   709 way of changing the user's settings is via
   710 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   711 script.
   712 
   713 * Multithreading.max_threads := 0 refers to the number of actual CPU
   714 cores of the underlying machine, which is a good starting point for
   715 optimal performance tuning.  The corresponding usedir option -M allows
   716 "max" as an alias for "0".  WARNING: does not work on certain versions
   717 of Mac OS (with Poly/ML 5.1).
   718 
   719 * isabelle-process: non-ML sessions are run with "nice", to reduce the
   720 adverse effect of Isabelle flooding interactive front-ends (notably
   721 ProofGeneral / XEmacs).
   722 
   723 
   724 
   725 New in Isabelle2007 (November 2007)
   726 -----------------------------------
   727 
   728 *** General ***
   729 
   730 * More uniform information about legacy features, notably a
   731 warning/error of "Legacy feature: ...", depending on the state of the
   732 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   733 legacy features will disappear eventually.
   734 
   735 * Theory syntax: the header format ``theory A = B + C:'' has been
   736 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   737 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   738 
   739 * Theory syntax: the old non-Isar theory file format has been
   740 discontinued altogether.  Note that ML proof scripts may still be used
   741 with Isar theories; migration is usually quite simple with the ML
   742 function use_legacy_bindings.  INCOMPATIBILITY.
   743 
   744 * Theory syntax: some popular names (e.g. 'class', 'declaration',
   745 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
   746 quotes.
   747 
   748 * Theory loader: be more serious about observing the static theory
   749 header specifications (including optional directories), but not the
   750 accidental file locations of previously successful loads.  The strict
   751 update policy of former update_thy is now already performed by
   752 use_thy, so the former has been removed; use_thys updates several
   753 theories simultaneously, just as 'imports' within a theory header
   754 specification, but without merging the results.  Potential
   755 INCOMPATIBILITY: may need to refine theory headers and commands
   756 ROOT.ML which depend on load order.
   757 
   758 * Theory loader: optional support for content-based file
   759 identification, instead of the traditional scheme of full physical
   760 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
   761 (cf. the system manual).  The new scheme allows to work with
   762 non-finished theories in persistent session images, such that source
   763 files may be moved later on without requiring reloads.
   764 
   765 * Theory loader: old-style ML proof scripts being *attached* to a thy
   766 file (with the same base name as the theory) are considered a legacy
   767 feature, which will disappear eventually. Even now, the theory loader
   768 no longer maintains dependencies on such files.
   769 
   770 * Syntax: the scope for resolving ambiguities via type-inference is
   771 now limited to individual terms, instead of whole simultaneous
   772 specifications as before. This greatly reduces the complexity of the
   773 syntax module and improves flexibility by separating parsing and
   774 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
   775 'fixes' etc.) are required in rare situations.
   776 
   777 * Syntax: constants introduced by new-style packages ('definition',
   778 'abbreviation' etc.) are passed through the syntax module in
   779 ``authentic mode''. This means that associated mixfix annotations
   780 really stick to such constants, independently of potential name space
   781 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   782 trees are represented slightly differently, may need to adapt syntax
   783 translations accordingly. Use CONST marker in 'translations' and
   784 @{const_syntax} antiquotation in 'parse_translation' etc.
   785 
   786 * Legacy goal package: reduced interface to the bare minimum required
   787 to keep existing proof scripts running.  Most other user-level
   788 functions are now part of the OldGoals structure, which is *not* open
   789 by default (consider isatool expandshort before open OldGoals).
   790 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   791 these tend to cause confusion about the actual goal (!) context being
   792 used here, which is not necessarily the same as the_context().
   793 
   794 * Command 'find_theorems': supports "*" wild-card in "name:"
   795 criterion; "with_dups" option.  Certain ProofGeneral versions might
   796 support a specific search form (see ProofGeneral/CHANGES).
   797 
   798 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   799 by default, which means that "prems" (and also "fixed variables") are
   800 suppressed from proof state output.  Note that the ProofGeneral
   801 settings mechanism allows to change and save options persistently, but
   802 older versions of Isabelle will fail to start up if a negative prems
   803 limit is imposed.
   804 
   805 * Local theory targets may be specified by non-nested blocks of
   806 ``context/locale/class ... begin'' followed by ``end''.  The body may
   807 contain definitions, theorems etc., including any derived mechanism
   808 that has been implemented on top of these primitives.  This concept
   809 generalizes the existing ``theorem (in ...)'' towards more versatility
   810 and scalability.
   811 
   812 * Proof General interface: proper undo of final 'end' command;
   813 discontinued Isabelle/classic mode (ML proof scripts).
   814 
   815 
   816 *** Document preparation ***
   817 
   818 * Added antiquotation @{theory name} which prints the given name,
   819 after checking that it refers to a valid ancestor theory in the
   820 current context.
   821 
   822 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   823 check the given source text as ML type/structure, printing verbatim.
   824 
   825 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   826 "c args == rhs" given in the current context.  (Any number of
   827 arguments may be given on the LHS.)
   828 
   829 
   830 *** Pure ***
   831 
   832 * The 'class' package offers a combination of axclass and locale to
   833 achieve Haskell-like type classes in Isabelle.  Definitions and
   834 theorems within a class context produce both relative results (with
   835 implicit parameters according to the locale context), and polymorphic
   836 constants with qualified polymorphism (according to the class
   837 context).  Within the body context of a 'class' target, a separate
   838 syntax layer ("user space type system") takes care of converting
   839 between global polymorphic consts and internal locale representation.
   840 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   841 "isatool doc classes" provides a tutorial.
   842 
   843 * Generic code generator framework allows to generate executable
   844 code for ML and Haskell (including Isabelle classes).  A short usage
   845 sketch:
   846 
   847     internal compilation:
   848         export_code <list of constants (term syntax)> in SML
   849     writing SML code to a file:
   850         export_code <list of constants (term syntax)> in SML <filename>
   851     writing OCaml code to a file:
   852         export_code <list of constants (term syntax)> in OCaml <filename>
   853     writing Haskell code to a bunch of files:
   854         export_code <list of constants (term syntax)> in Haskell <filename>
   855 
   856     evaluating closed propositions to True/False using code generation:
   857         method ``eval''
   858 
   859 Reasonable default setup of framework in HOL.
   860 
   861 Theorem attributs for selecting and transforming function equations theorems:
   862 
   863     [code fun]:        select a theorem as function equation for a specific constant
   864     [code fun del]:    deselect a theorem as function equation for a specific constant
   865     [code inline]:     select an equation theorem for unfolding (inlining) in place
   866     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   867 
   868 User-defined serializations (target in {SML, OCaml, Haskell}):
   869 
   870     code_const <and-list of constants (term syntax)>
   871       {(target) <and-list of const target syntax>}+
   872 
   873     code_type <and-list of type constructors>
   874       {(target) <and-list of type target syntax>}+
   875 
   876     code_instance <and-list of instances>
   877       {(target)}+
   878         where instance ::= <type constructor> :: <class>
   879 
   880     code_class <and_list of classes>
   881       {(target) <and-list of class target syntax>}+
   882         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   883 
   884 code_instance and code_class only are effective to target Haskell.
   885 
   886 For example usage see src/HOL/ex/Codegenerator.thy and
   887 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   888 generation from Isabelle/HOL theories is available via "isatool doc
   889 codegen".
   890 
   891 * Code generator: consts in 'consts_code' Isar commands are now
   892 referred to by usual term syntax (including optional type
   893 annotations).
   894 
   895 * Command 'no_translations' removes translation rules from theory
   896 syntax.
   897 
   898 * Overloaded definitions are now actually checked for acyclic
   899 dependencies.  The overloading scheme is slightly more general than
   900 that of Haskell98, although Isabelle does not demand an exact
   901 correspondence to type class and instance declarations.
   902 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   903 exotic versions of overloading -- at the discretion of the user!
   904 
   905 Polymorphic constants are represented via type arguments, i.e. the
   906 instantiation that matches an instance against the most general
   907 declaration given in the signature.  For example, with the declaration
   908 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   909 as c(nat).  Overloading is essentially simultaneous structural
   910 recursion over such type arguments.  Incomplete specification patterns
   911 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   912 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   913 Command 'print_theory' outputs the normalized system of recursive
   914 equations, see section "definitions".
   915 
   916 * Configuration options are maintained within the theory or proof
   917 context (with name and type bool/int/string), providing a very simple
   918 interface to a poor-man's version of general context data.  Tools may
   919 declare options in ML (e.g. using Attrib.config_int) and then refer to
   920 these values using Config.get etc.  Users may change options via an
   921 associated attribute of the same name.  This form of context
   922 declaration works particularly well with commands 'declare' or
   923 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   924 very easy to avoid global references, which would not observe Isar
   925 toplevel undo/redo and fail to work with multithreading.
   926 
   927 Various global ML references of Pure and HOL have been turned into
   928 configuration options:
   929 
   930   Unify.search_bound		unify_search_bound
   931   Unify.trace_bound		unify_trace_bound
   932   Unify.trace_simp		unify_trace_simp
   933   Unify.trace_types		unify_trace_types
   934   Simplifier.simp_depth_limit	simp_depth_limit
   935   Blast.depth_limit		blast_depth_limit
   936   DatatypeProp.dtK		datatype_distinctness_limit
   937   fast_arith_neq_limit  	fast_arith_neq_limit
   938   fast_arith_split_limit	fast_arith_split_limit
   939 
   940 * Named collections of theorems may be easily installed as context
   941 data using the functor NamedThmsFun (see also
   942 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   943 attributes; there is also a toplevel print command.  This facility is
   944 just a common case of general context data, which is the preferred way
   945 for anything more complex than just a list of facts in canonical
   946 order.
   947 
   948 * Isar: command 'declaration' augments a local theory by generic
   949 declaration functions written in ML.  This enables arbitrary content
   950 being added to the context, depending on a morphism that tells the
   951 difference of the original declaration context wrt. the application
   952 context encountered later on.
   953 
   954 * Isar: proper interfaces for simplification procedures.  Command
   955 'simproc_setup' declares named simprocs (with match patterns, and body
   956 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   957 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   958 
   959 * Isar: an extra pair of brackets around attribute declarations
   960 abbreviates a theorem reference involving an internal dummy fact,
   961 which will be ignored later --- only the effect of the attribute on
   962 the background context will persist.  This form of in-place
   963 declarations is particularly useful with commands like 'declare' and
   964 'using', for example ``have A using [[simproc a]] by simp''.
   965 
   966 * Isar: method "assumption" (and implicit closing of subproofs) now
   967 takes simple non-atomic goal assumptions into account: after applying
   968 an assumption as a rule the resulting subgoals are solved by atomic
   969 assumption steps.  This is particularly useful to finish 'obtain'
   970 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   971 without referring to the original premise "!!x. P x ==> thesis" in the
   972 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   973 more permissive.
   974 
   975 * Isar: implicit use of prems from the Isar proof context is
   976 considered a legacy feature.  Common applications like ``have A .''
   977 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   978 referencing facts explicitly here improves readability and
   979 maintainability of proof texts.
   980 
   981 * Isar: improper proof element 'guess' is like 'obtain', but derives
   982 the obtained context from the course of reasoning!  For example:
   983 
   984   assume "EX x y. A x & B y"   -- "any previous fact"
   985   then guess x and y by clarify
   986 
   987 This technique is potentially adventurous, depending on the facts and
   988 proof tools being involved here.
   989 
   990 * Isar: known facts from the proof context may be specified as literal
   991 propositions, using ASCII back-quote syntax.  This works wherever
   992 named facts used to be allowed so far, in proof commands, proof
   993 methods, attributes etc.  Literal facts are retrieved from the context
   994 according to unification of type and term parameters.  For example,
   995 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   996 theorems in the current context, then these are valid literal facts:
   997 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   998 
   999 There is also a proof method "fact" which does the same composition
  1000 for explicit goal states, e.g. the following proof texts coincide with
  1001 certain special cases of literal facts:
  1002 
  1003   have "A" by fact                 ==  note `A`
  1004   have "A ==> B" by fact           ==  note `A ==> B`
  1005   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1006   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1007 
  1008 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1009 outer syntax.  Thus symbolic identifiers may be used without
  1010 additional white space in declarations like this: ``assume *: A''.
  1011 
  1012 * Isar: 'print_facts' prints all local facts of the current context,
  1013 both named and unnamed ones.
  1014 
  1015 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1016 
  1017   def x == "t" and y == "u"
  1018 
  1019 * Isar: added command 'unfolding', which is structurally similar to
  1020 'using', but affects both the goal state and facts by unfolding given
  1021 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1022 'unfolded' attribute may be replaced by first-class proof text.
  1023 
  1024 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1025 and command 'unfolding' now all support object-level equalities
  1026 (potentially conditional).  The underlying notion of rewrite rule is
  1027 analogous to the 'rule_format' attribute, but *not* that of the
  1028 Simplifier (which is usually more generous).
  1029 
  1030 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1031 premises of a theorem by n. Useful in conjunction with drule.
  1032 
  1033 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1034 method expression within a sandbox consisting of the first N
  1035 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1036 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1037 simplifies all new goals that emerge from applying rule foo to the
  1038 originally first one.
  1039 
  1040 * Isar: schematic goals are no longer restricted to higher-order
  1041 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1042 expected.
  1043 
  1044 * Isar: the conclusion of a long theorem statement is now either
  1045 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1046 (essentially a disjunction of cases with local parameters and
  1047 assumptions).  The latter allows to express general elimination rules
  1048 adequately; in this notation common elimination rules look like this:
  1049 
  1050   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1051     assumes "EX x. P x"
  1052     obtains x where "P x"
  1053 
  1054   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1055     assumes "A & B"
  1056     obtains A and B
  1057 
  1058   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1059     assumes "A | B"
  1060     obtains
  1061       A
  1062     | B
  1063 
  1064 The subsequent classical rules even refer to the formal "thesis"
  1065 explicitly:
  1066 
  1067   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1068     obtains "~ thesis"
  1069 
  1070   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1071     obtains "thesis ==> something"
  1072 
  1073 The actual proof of an 'obtains' statement is analogous to that of the
  1074 Isar proof element 'obtain', only that there may be several cases.
  1075 Optional case names may be specified in parentheses; these will be
  1076 available both in the present proof and as annotations in the
  1077 resulting rule, for later use with the 'cases' method (cf. attribute
  1078 case_names).
  1079 
  1080 * Isar: the assumptions of a long theorem statement are available as
  1081 "assms" fact in the proof context.  This is more appropriate than the
  1082 (historical) "prems", which refers to all assumptions of the current
  1083 context, including those from the target locale, proof body etc.
  1084 
  1085 * Isar: 'print_statement' prints theorems from the current theory or
  1086 proof context in long statement form, according to the syntax of a
  1087 top-level lemma.
  1088 
  1089 * Isar: 'obtain' takes an optional case name for the local context
  1090 introduction rule (default "that").
  1091 
  1092 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1093 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1094 to occur.
  1095 
  1096 * Pure: syntax "CONST name" produces a fully internalized constant
  1097 according to the current context.  This is particularly useful for
  1098 syntax translations that should refer to internal constant
  1099 representations independently of name spaces.
  1100 
  1101 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1102 instead of "FOO ". This allows multiple binder declarations to coexist
  1103 in the same context.  INCOMPATIBILITY.
  1104 
  1105 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1106 primitive that also works in a locale context (both for constants and
  1107 fixed variables). Type declaration and internal syntactic representation
  1108 of given constants retrieved from the context. Likewise, the
  1109 'no_notation' command allows to remove given syntax annotations from the
  1110 current context.
  1111 
  1112 * Isar/locales: new derived specification elements 'axiomatization',
  1113 'definition', 'abbreviation', which support type-inference, admit
  1114 object-level specifications (equality, equivalence).  See also the
  1115 isar-ref manual.  Examples:
  1116 
  1117   axiomatization
  1118     eq  (infix "===" 50) where
  1119     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1120 
  1121   definition "f x y = x + y + 1"
  1122   definition g where "g x = f x x"
  1123 
  1124   abbreviation
  1125     neq  (infix "=!=" 50) where
  1126     "x =!= y == ~ (x === y)"
  1127 
  1128 These specifications may be also used in a locale context.  Then the
  1129 constants being introduced depend on certain fixed parameters, and the
  1130 constant name is qualified by the locale base name.  An internal
  1131 abbreviation takes care for convenient input and output, making the
  1132 parameters implicit and using the original short name.  See also
  1133 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1134 entities from a monomorphic theory.
  1135 
  1136 Presently, abbreviations are only available 'in' a target locale, but
  1137 not inherited by general import expressions.  Also note that
  1138 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1139 'translations' in common applications.  The "no_abbrevs" print mode
  1140 prevents folding of abbreviations in term output.
  1141 
  1142 Concrete syntax is attached to specified constants in internal form,
  1143 independently of name spaces.  The parse tree representation is
  1144 slightly different -- use 'notation' instead of raw 'syntax', and
  1145 'translations' with explicit "CONST" markup to accommodate this.
  1146 
  1147 * Pure/Isar: unified syntax for new-style specification mechanisms
  1148 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1149 full type inference and dummy patterns ("_").  For example:
  1150 
  1151   definition "K x _ = x"
  1152 
  1153   inductive conj for A B
  1154   where "A ==> B ==> conj A B"
  1155 
  1156 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1157 the current context.  Print mode "no_abbrevs" prevents inversion of
  1158 abbreviations on output.
  1159 
  1160 * Isar/locales: improved parameter handling: use of locales "var" and
  1161 "struct" no longer necessary; - parameter renamings are no longer
  1162 required to be injective.  For example, this allows to define
  1163 endomorphisms as locale endom = homom mult mult h.
  1164 
  1165 * Isar/locales: changed the way locales with predicates are defined.
  1166 Instead of accumulating the specification, the imported expression is
  1167 now an interpretation.  INCOMPATIBILITY: different normal form of
  1168 locale expressions.  In particular, in interpretations of locales with
  1169 predicates, goals repesenting already interpreted fragments are not
  1170 removed automatically.  Use methods `intro_locales' and
  1171 `unfold_locales'; see below.
  1172 
  1173 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1174 provide backward reasoning on locales predicates.  The methods are
  1175 aware of interpretations and discharge corresponding goals.
  1176 `intro_locales' is less aggressive then `unfold_locales' and does not
  1177 unfold predicates to assumptions.
  1178 
  1179 * Isar/locales: the order in which locale fragments are accumulated
  1180 has changed.  This enables to override declarations from fragments due
  1181 to interpretations -- for example, unwanted simp rules.
  1182 
  1183 * Isar/locales: interpretation in theories and proof contexts has been
  1184 extended.  One may now specify (and prove) equations, which are
  1185 unfolded in interpreted theorems.  This is useful for replacing
  1186 defined concepts (constants depending on locale parameters) by
  1187 concepts already existing in the target context.  Example:
  1188 
  1189   interpretation partial_order ["op <= :: [int, int] => bool"]
  1190     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1191 
  1192 Typically, the constant `partial_order.less' is created by a
  1193 definition specification element in the context of locale
  1194 partial_order.
  1195 
  1196 * Method "induct": improved internal context management to support
  1197 local fixes and defines on-the-fly. Thus explicit meta-level
  1198 connectives !!  and ==> are rarely required anymore in inductive goals
  1199 (using object-logic connectives for this purpose has been long
  1200 obsolete anyway). Common proof patterns are explained in
  1201 src/HOL/Induct/Common_Patterns.thy, see also
  1202 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1203 examples.
  1204 
  1205 * Method "induct": improved handling of simultaneous goals. Instead of
  1206 introducing object-level conjunction, the statement is now split into
  1207 several conclusions, while the corresponding symbolic cases are nested
  1208 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1209 see src/HOL/Induct/Common_Patterns.thy, for example.
  1210 
  1211 * Method "induct": mutual induction rules are now specified as a list
  1212 of rule sharing the same induction cases. HOL packages usually provide
  1213 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1214 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1215 mutual induction rules differently, i.e. like this:
  1216 
  1217   (induct rule: foo_bar.inducts)
  1218   (induct set: foo bar)
  1219   (induct pred: foo bar)
  1220   (induct type: foo bar)
  1221 
  1222 The ML function ProjectRule.projections turns old-style rules into the
  1223 new format.
  1224 
  1225 * Method "coinduct": dual of induction, see
  1226 src/HOL/Library/Coinductive_List.thy for various examples.
  1227 
  1228 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1229 considered a legacy feature.
  1230 
  1231 * Attribute "symmetric" produces result with standardized schematic
  1232 variables (index 0).  Potential INCOMPATIBILITY.
  1233 
  1234 * Simplifier: by default the simplifier trace only shows top level
  1235 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1236 default. Thus there is less danger of being flooded by the trace. The
  1237 trace indicates where parts have been suppressed.
  1238   
  1239 * Provers/classical: removed obsolete classical version of elim_format
  1240 attribute; classical elim/dest rules are now treated uniformly when
  1241 manipulating the claset.
  1242 
  1243 * Provers/classical: stricter checks to ensure that supplied intro,
  1244 dest and elim rules are well-formed; dest and elim rules must have at
  1245 least one premise.
  1246 
  1247 * Provers/classical: attributes dest/elim/intro take an optional
  1248 weight argument for the rule (just as the Pure versions).  Weights are
  1249 ignored by automated tools, but determine the search order of single
  1250 rule steps.
  1251 
  1252 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1253 where the body does not mention the bound variable.  Note that dummy
  1254 patterns implicitly depend on their context of bounds, which makes
  1255 "{_. _}" match any set comprehension as expected.  Potential
  1256 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1257 constant "_idtdummy" in the binding position.
  1258 
  1259 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1260 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1261 for example "A -> B" => "Pi A (%_. B)".
  1262 
  1263 * Pure: 'class_deps' command visualizes the subclass relation, using
  1264 the graph browser tool.
  1265 
  1266 * Pure: 'print_theory' now suppresses certain internal declarations by
  1267 default; use '!' option for full details.
  1268 
  1269 
  1270 *** HOL ***
  1271 
  1272 * Method "metis" proves goals by applying the Metis general-purpose
  1273 resolution prover (see also http://gilith.com/software/metis/).
  1274 Examples are in the directory MetisExamples.  WARNING: the
  1275 Isabelle/HOL-Metis integration does not yet work properly with
  1276 multi-threading.
  1277   
  1278 * Command 'sledgehammer' invokes external automatic theorem provers as
  1279 background processes.  It generates calls to the "metis" method if
  1280 successful. These can be pasted into the proof.  Users do not have to
  1281 wait for the automatic provers to return.  WARNING: does not really
  1282 work with multi-threading.
  1283 
  1284 * New "auto_quickcheck" feature tests outermost goal statements for
  1285 potential counter-examples.  Controlled by ML references
  1286 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1287 5000 milliseconds).  Fails silently if statements is outside of
  1288 executable fragment, or any other codgenerator problem occurs.
  1289 
  1290 * New constant "undefined" with axiom "undefined x = undefined".
  1291 
  1292 * Added class "HOL.eq", allowing for code generation with polymorphic
  1293 equality.
  1294 
  1295 * Some renaming of class constants due to canonical name prefixing in
  1296 the new 'class' package:
  1297 
  1298     HOL.abs ~> HOL.abs_class.abs
  1299     HOL.divide ~> HOL.divide_class.divide
  1300     0 ~> HOL.zero_class.zero
  1301     1 ~> HOL.one_class.one
  1302     op + ~> HOL.plus_class.plus
  1303     op - ~> HOL.minus_class.minus
  1304     uminus ~> HOL.minus_class.uminus
  1305     op * ~> HOL.times_class.times
  1306     op < ~> HOL.ord_class.less
  1307     op <= > HOL.ord_class.less_eq
  1308     Nat.power ~> Power.power_class.power
  1309     Nat.size ~> Nat.size_class.size
  1310     Numeral.number_of ~> Numeral.number_class.number_of
  1311     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1312     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1313     Orderings.min ~> Orderings.ord_class.min
  1314     Orderings.max ~> Orderings.ord_class.max
  1315     Divides.op div ~> Divides.div_class.div
  1316     Divides.op mod ~> Divides.div_class.mod
  1317     Divides.op dvd ~> Divides.div_class.dvd
  1318 
  1319 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1320 
  1321 a) User-defined constants using any of the names "plus", "minus",
  1322 "times", "less" or "less_eq". The standard syntax translations for
  1323 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1324 names.
  1325 
  1326 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1327 INCOMPATIBILITY: use more specific names.
  1328 
  1329 c) Permutative equations (e.g. "a + b = b + a")
  1330 Since the change of names also changes the order of terms, permutative
  1331 rewrite rules may get applied in a different order. Experience shows
  1332 that this is rarely the case (only two adaptions in the whole Isabelle
  1333 distribution).  INCOMPATIBILITY: rewrite proofs
  1334 
  1335 d) ML code directly refering to constant names
  1336 This in general only affects hand-written proof tactics, simprocs and
  1337 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1338 Consider using @{const_name} antiquotation.
  1339 
  1340 * New class "default" with associated constant "default".
  1341 
  1342 * Function "sgn" is now overloaded and available on int, real, complex
  1343 (and other numeric types), using class "sgn".  Two possible defs of
  1344 sgn are given as equational assumptions in the classes sgn_if and
  1345 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1346 INCOMPATIBILITY.
  1347 
  1348 * Locale "partial_order" now unified with class "order" (cf. theory
  1349 Orderings), added parameter "less".  INCOMPATIBILITY.
  1350 
  1351 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1352 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1353 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1354 
  1355 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1356 changed order of proof goals in instance proofs.
  1357 
  1358 * The transitivity reasoner for partial and linear orders is set up
  1359 for classes "order" and "linorder".  Instances of the reasoner are available
  1360 in all contexts importing or interpreting the corresponding locales.
  1361 Method "order" invokes the reasoner separately; the reasoner
  1362 is also integrated with the Simplifier as a solver.  Diagnostic
  1363 command 'print_orders' shows the available instances of the reasoner
  1364 in the current context.
  1365 
  1366 * Localized monotonicity predicate in theory "Orderings"; integrated
  1367 lemmas max_of_mono and min_of_mono with this predicate.
  1368 INCOMPATIBILITY.
  1369 
  1370 * Formulation of theorem "dense" changed slightly due to integration
  1371 with new class dense_linear_order.
  1372 
  1373 * Uniform lattice theory development in HOL.
  1374 
  1375     constants "meet" and "join" now named "inf" and "sup"
  1376     constant "Meet" now named "Inf"
  1377 
  1378     classes "meet_semilorder" and "join_semilorder" now named
  1379       "lower_semilattice" and "upper_semilattice"
  1380     class "lorder" now named "lattice"
  1381     class "comp_lat" now named "complete_lattice"
  1382 
  1383     Instantiation of lattice classes allows explicit definitions
  1384     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1385 
  1386   INCOMPATIBILITY.  Theorem renames:
  1387 
  1388     meet_left_le            ~> inf_le1
  1389     meet_right_le           ~> inf_le2
  1390     join_left_le            ~> sup_ge1
  1391     join_right_le           ~> sup_ge2
  1392     meet_join_le            ~> inf_sup_ord
  1393     le_meetI                ~> le_infI
  1394     join_leI                ~> le_supI
  1395     le_meet                 ~> le_inf_iff
  1396     le_join                 ~> ge_sup_conv
  1397     meet_idempotent         ~> inf_idem
  1398     join_idempotent         ~> sup_idem
  1399     meet_comm               ~> inf_commute
  1400     join_comm               ~> sup_commute
  1401     meet_leI1               ~> le_infI1
  1402     meet_leI2               ~> le_infI2
  1403     le_joinI1               ~> le_supI1
  1404     le_joinI2               ~> le_supI2
  1405     meet_assoc              ~> inf_assoc
  1406     join_assoc              ~> sup_assoc
  1407     meet_left_comm          ~> inf_left_commute
  1408     meet_left_idempotent    ~> inf_left_idem
  1409     join_left_comm          ~> sup_left_commute
  1410     join_left_idempotent    ~> sup_left_idem
  1411     meet_aci                ~> inf_aci
  1412     join_aci                ~> sup_aci
  1413     le_def_meet             ~> le_iff_inf
  1414     le_def_join             ~> le_iff_sup
  1415     join_absorp2            ~> sup_absorb2
  1416     join_absorp1            ~> sup_absorb1
  1417     meet_absorp1            ~> inf_absorb1
  1418     meet_absorp2            ~> inf_absorb2
  1419     meet_join_absorp        ~> inf_sup_absorb
  1420     join_meet_absorp        ~> sup_inf_absorb
  1421     distrib_join_le         ~> distrib_sup_le
  1422     distrib_meet_le         ~> distrib_inf_le
  1423 
  1424     add_meet_distrib_left   ~> add_inf_distrib_left
  1425     add_join_distrib_left   ~> add_sup_distrib_left
  1426     is_join_neg_meet        ~> is_join_neg_inf
  1427     is_meet_neg_join        ~> is_meet_neg_sup
  1428     add_meet_distrib_right  ~> add_inf_distrib_right
  1429     add_join_distrib_right  ~> add_sup_distrib_right
  1430     add_meet_join_distribs  ~> add_sup_inf_distribs
  1431     join_eq_neg_meet        ~> sup_eq_neg_inf
  1432     meet_eq_neg_join        ~> inf_eq_neg_sup
  1433     add_eq_meet_join        ~> add_eq_inf_sup
  1434     meet_0_imp_0            ~> inf_0_imp_0
  1435     join_0_imp_0            ~> sup_0_imp_0
  1436     meet_0_eq_0             ~> inf_0_eq_0
  1437     join_0_eq_0             ~> sup_0_eq_0
  1438     neg_meet_eq_join        ~> neg_inf_eq_sup
  1439     neg_join_eq_meet        ~> neg_sup_eq_inf
  1440     join_eq_if              ~> sup_eq_if
  1441 
  1442     mono_meet               ~> mono_inf
  1443     mono_join               ~> mono_sup
  1444     meet_bool_eq            ~> inf_bool_eq
  1445     join_bool_eq            ~> sup_bool_eq
  1446     meet_fun_eq             ~> inf_fun_eq
  1447     join_fun_eq             ~> sup_fun_eq
  1448     meet_set_eq             ~> inf_set_eq
  1449     join_set_eq             ~> sup_set_eq
  1450     meet1_iff               ~> inf1_iff
  1451     meet2_iff               ~> inf2_iff
  1452     meet1I                  ~> inf1I
  1453     meet2I                  ~> inf2I
  1454     meet1D1                 ~> inf1D1
  1455     meet2D1                 ~> inf2D1
  1456     meet1D2                 ~> inf1D2
  1457     meet2D2                 ~> inf2D2
  1458     meet1E                  ~> inf1E
  1459     meet2E                  ~> inf2E
  1460     join1_iff               ~> sup1_iff
  1461     join2_iff               ~> sup2_iff
  1462     join1I1                 ~> sup1I1
  1463     join2I1                 ~> sup2I1
  1464     join1I1                 ~> sup1I1
  1465     join2I2                 ~> sup1I2
  1466     join1CI                 ~> sup1CI
  1467     join2CI                 ~> sup2CI
  1468     join1E                  ~> sup1E
  1469     join2E                  ~> sup2E
  1470 
  1471     is_meet_Meet            ~> is_meet_Inf
  1472     Meet_bool_def           ~> Inf_bool_def
  1473     Meet_fun_def            ~> Inf_fun_def
  1474     Meet_greatest           ~> Inf_greatest
  1475     Meet_lower              ~> Inf_lower
  1476     Meet_set_def            ~> Inf_set_def
  1477 
  1478     Sup_def                 ~> Sup_Inf
  1479     Sup_bool_eq             ~> Sup_bool_def
  1480     Sup_fun_eq              ~> Sup_fun_def
  1481     Sup_set_eq              ~> Sup_set_def
  1482 
  1483     listsp_meetI            ~> listsp_infI
  1484     listsp_meet_eq          ~> listsp_inf_eq
  1485 
  1486     meet_min                ~> inf_min
  1487     join_max                ~> sup_max
  1488 
  1489 * Added syntactic class "size"; overloaded constant "size" now has
  1490 type "'a::size ==> bool"
  1491 
  1492 * Internal reorganisation of `size' of datatypes: size theorems
  1493 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1494 simplification rules by default!); theorems "prod.size" now named
  1495 "*.size".
  1496 
  1497 * Class "div" now inherits from class "times" rather than "type".
  1498 INCOMPATIBILITY.
  1499 
  1500 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1501 Linorder etc.  have disappeared; operations defined in terms of
  1502 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1503 
  1504 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1505 
  1506 * HOL-Word: New extensive library and type for generic, fixed size
  1507 machine words, with arithemtic, bit-wise, shifting and rotating
  1508 operations, reflection into int, nat, and bool lists, automation for
  1509 linear arithmetic (by automatic reflection into nat or int), including
  1510 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1511 arithmetic type classes, supporting automatic simplification of
  1512 numerals on all operations.
  1513 
  1514 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1515 
  1516 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1517 
  1518 * Code generator library theories:
  1519   - Code_Integer represents HOL integers by big integer literals in target
  1520     languages.
  1521   - Code_Char represents HOL characters by character literals in target
  1522     languages.
  1523   - Code_Char_chr like Code_Char, but also offers treatment of character
  1524     codes; includes Code_Integer.
  1525   - Executable_Set allows to generate code for finite sets using lists.
  1526   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1527     denominator).
  1528   - Executable_Real implements a subset of real numbers, namly those
  1529     representable by rational numbers.
  1530   - Efficient_Nat implements natural numbers by integers, which in general will
  1531     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1532     includes Code_Integer.
  1533   - Code_Index provides an additional datatype index which is mapped to
  1534     target-language built-in integers.
  1535   - Code_Message provides an additional datatype message_string which is isomorphic to
  1536     strings; messages are mapped to target-language strings.
  1537 
  1538 * New package for inductive predicates
  1539 
  1540   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1541 
  1542     inductive
  1543       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1544       for z_1 :: U_1 and ... and z_n :: U_m
  1545     where
  1546       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1547     | ...
  1548 
  1549   with full support for type-inference, rather than
  1550 
  1551     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1552 
  1553     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1554     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1555 
  1556     inductive "s z_1 ... z_m"
  1557     intros
  1558       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1559       ...
  1560 
  1561   For backward compatibility, there is a wrapper allowing inductive
  1562   sets to be defined with the new package via
  1563 
  1564     inductive_set
  1565       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1566       for z_1 :: U_1 and ... and z_n :: U_m
  1567     where
  1568       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1569     | ...
  1570 
  1571   or
  1572 
  1573     inductive_set
  1574       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1575       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1576       for z_1 :: U_1 and ... and z_n :: U_m
  1577     where
  1578       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1579     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1580     | ...
  1581 
  1582   if the additional syntax "p ..." is required.
  1583 
  1584   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1585   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1586 
  1587   INCOMPATIBILITIES:
  1588 
  1589   - Since declaration and definition of inductive sets or predicates
  1590     is no longer separated, abbreviations involving the newly
  1591     introduced sets or predicates must be specified together with the
  1592     introduction rules after the 'where' keyword (see above), rather
  1593     than before the actual inductive definition.
  1594 
  1595   - The variables in induction and elimination rules are now
  1596     quantified in the order of their occurrence in the introduction
  1597     rules, rather than in alphabetical order. Since this may break
  1598     some proofs, these proofs either have to be repaired, e.g. by
  1599     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1600     statements of the form
  1601 
  1602       case (rule_i a_i_1 ... a_i_{k_i})
  1603 
  1604     or the old order of quantification has to be restored by explicitly adding
  1605     meta-level quantifiers in the introduction rules, i.e.
  1606 
  1607       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1608 
  1609   - The format of the elimination rules is now
  1610 
  1611       p z_1 ... z_m x_1 ... x_n ==>
  1612         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1613         ==> ... ==> P
  1614 
  1615     for predicates and
  1616 
  1617       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1618         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1619         ==> ... ==> P
  1620 
  1621     for sets rather than
  1622 
  1623       x : s z_1 ... z_m ==>
  1624         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1625         ==> ... ==> P
  1626 
  1627     This may require terms in goals to be expanded to n-tuples
  1628     (e.g. using case_tac or simplification with the split_paired_all
  1629     rule) before the above elimination rule is applicable.
  1630 
  1631   - The elimination or case analysis rules for (mutually) inductive
  1632     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1633     list of rules "p_1_..._p_k.elims" is no longer available.
  1634 
  1635 * New package "function"/"fun" for general recursive functions,
  1636 supporting mutual and nested recursion, definitions in local contexts,
  1637 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1638 for small examples, and the separate tutorial on the function
  1639 package. The old recdef "package" is still available as before, but
  1640 users are encouraged to use the new package.
  1641 
  1642 * Method "lexicographic_order" automatically synthesizes termination
  1643 relations as lexicographic combinations of size measures. 
  1644 
  1645 * Case-expressions allow arbitrary constructor-patterns (including
  1646 "_") and take their order into account, like in functional
  1647 programming.  Internally, this is translated into nested
  1648 case-expressions; missing cases are added and mapped to the predefined
  1649 constant "undefined". In complicated cases printing may no longer show
  1650 the original input but the internal form. Lambda-abstractions allow
  1651 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1652 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1653 variable.
  1654 
  1655 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1656 is an abbreviation for "of_nat :: nat => int". The simplification
  1657 rules for "of_nat" have been changed to work like "int" did
  1658 previously.  Potential INCOMPATIBILITY:
  1659   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1660   - of_nat_diff and of_nat_mult are no longer default simp rules
  1661 
  1662 * Method "algebra" solves polynomial equations over (semi)rings using
  1663 Groebner bases. The (semi)ring structure is defined by locales and the
  1664 tool setup depends on that generic context. Installing the method for
  1665 a specific type involves instantiating the locale and possibly adding
  1666 declarations for computation on the coefficients.  The method is
  1667 already instantiated for natural numbers and for the axiomatic class
  1668 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1669 CALCULEMUS 2007 for the general principles underlying this
  1670 architecture of context-aware proof-tools.
  1671 
  1672 * Method "ferrack" implements quantifier elimination over
  1673 special-purpose dense linear orders using locales (analogous to
  1674 "algebra"). The method is already installed for class
  1675 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1676 rat, etc.
  1677 
  1678 * Former constant "List.op @" now named "List.append".  Use ML
  1679 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1680 circumvent possible incompatibilities when working on ML level.
  1681 
  1682 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1683 
  1684 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1685 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1686 
  1687 * New syntax for Haskell-like list comprehension (input only), eg.
  1688 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1689 
  1690 * The special syntax for function "filter" has changed from [x :
  1691 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1692 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1693 
  1694 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1695 defined on nat only, as an abbreviation for [a..<Suc b]
  1696 INCOMPATIBILITY.
  1697 
  1698 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1699 
  1700 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1701 
  1702 * New lemma collection field_simps (an extension of ring_simps) for
  1703 manipulating (in)equations involving division. Multiplies with all
  1704 denominators that can be proved to be non-zero (in equations) or
  1705 positive/negative (in inequations).
  1706 
  1707 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1708 have been improved and renamed to ring_simps, group_simps and
  1709 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1710 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1711 
  1712 * Theory Library/Commutative_Ring: switched from recdef to function
  1713 package; constants add, mul, pow now curried.  Infix syntax for
  1714 algebraic operations.
  1715 
  1716 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1717 INCOMPATIBILITY.
  1718 
  1719 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1720 INCOMPATIBILITY.
  1721 
  1722 * HOL/records: generalised field-update to take a function on the
  1723 field rather than the new value: r(|A := x|) is translated to A_update
  1724 (K x) r The K-combinator that is internally used is called K_record.
  1725 INCOMPATIBILITY: Usage of the plain update functions has to be
  1726 adapted.
  1727  
  1728 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1729 * x = 0, which are required for a semiring.  Richer structures do not
  1730 inherit from semiring_0 anymore, because this property is a theorem
  1731 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1732 there is more to prove, but this is mostly trivial.
  1733 
  1734 * Class "recpower" is generalized to arbitrary monoids, not just
  1735 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1736 commutativity or semiring properties additionally.
  1737 
  1738 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1739 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1740 better use 'abbreviation'.
  1741 
  1742 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1743 
  1744 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1745 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1746 significant changes for setting up numeral syntax for types:
  1747   - New constants Numeral.pred and Numeral.succ instead
  1748       of former Numeral.bin_pred and Numeral.bin_succ.
  1749   - Use integer operations instead of bin_add, bin_mult and so on.
  1750   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1751   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1752 
  1753 See src/HOL/Integ/IntArith.thy for an example setup.
  1754 
  1755 * Command 'normal_form' computes the normal form of a term that may
  1756 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1757 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1758 heavy-duty computations because the functions are compiled to ML
  1759 first.  Correspondingly, a method "normalization" is provided.  See
  1760 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1761 
  1762 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1763 25 like -->); output depends on the "iff" print_mode, the default is
  1764 "A = B" (with priority 50).
  1765 
  1766 * Relations less (<) and less_eq (<=) are also available on type bool.
  1767 Modified syntax to disallow nesting without explicit parentheses,
  1768 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1769 INCOMPATIBILITY.
  1770 
  1771 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1772 
  1773 * Relation composition operator "op O" now has precedence 75 and binds
  1774 stronger than union and intersection. INCOMPATIBILITY.
  1775 
  1776 * The old set interval syntax "{m..n(}" (and relatives) has been
  1777 removed.  Use "{m..<n}" (and relatives) instead.
  1778 
  1779 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1780 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1781 ``declare [[simproc del: neq]]''.
  1782 
  1783 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1784 True/False.
  1785 
  1786 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1787 
  1788 * Theorem setsum_mult renamed to setsum_right_distrib.
  1789 
  1790 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1791 ``rule'' method.
  1792 
  1793 * Reimplemented methods "sat" and "satx", with several improvements:
  1794 goals no longer need to be stated as "<prems> ==> False", equivalences
  1795 (i.e. "=" on type bool) are handled, variable names of the form
  1796 "lit_<n>" are no longer reserved, significant speedup.
  1797 
  1798 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1799 zChaff is still supported as well.
  1800 
  1801 * 'inductive' and 'datatype': provide projections of mutual rules,
  1802 bundled as foo_bar.inducts;
  1803 
  1804 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1805 Library.
  1806 
  1807 * Library: moved theory Accessible_Part to main HOL.
  1808 
  1809 * Library: added theory Coinductive_List of potentially infinite lists
  1810 as greatest fixed-point.
  1811 
  1812 * Library: added theory AssocList which implements (finite) maps as
  1813 association lists.
  1814 
  1815 * Method "evaluation" solves goals (i.e. a boolean expression)
  1816 efficiently by compiling it to ML.  The goal is "proved" (via an
  1817 oracle) if it evaluates to True.
  1818 
  1819 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1820 also when invoked by the simplifier.  This results in the Simplifier
  1821 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1822 Configuration option fast_arith_split_limit=0 recovers the old
  1823 behavior.
  1824 
  1825 * Support for hex (0x20) and binary (0b1001) numerals.
  1826 
  1827 * New method: reify eqs (t), where eqs are equations for an
  1828 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1829 parameter, computes a term s::'b and a list xs::'a list and proves the
  1830 theorem I xs s = t. This is also known as reification or quoting. The
  1831 resulting theorem is applied to the subgoal to substitute t with I xs
  1832 s.  If t is omitted, the subgoal itself is reified.
  1833 
  1834 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1835 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1836 where f is supposed to be a computable function (in the sense of code
  1837 generattion). The method uses reify to compute s and xs as above then
  1838 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1839 r and finally gets the theorem t = r, which is again applied to the
  1840 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1841 
  1842 * Reflection: Automatic reification now handels binding, an example is
  1843 available in src/HOL/ex/ReflectionEx.thy
  1844 
  1845 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1846 command 'statespace' that is similar to 'record', but introduces an
  1847 abstract specification based on the locale infrastructure instead of
  1848 HOL types.  This leads to extra flexibility in composing state spaces,
  1849 in particular multiple inheritance and renaming of components.
  1850 
  1851 
  1852 *** HOL-Complex ***
  1853 
  1854 * Hyperreal: Functions root and sqrt are now defined on negative real
  1855 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1856 Nonnegativity side conditions have been removed from many lemmas, so
  1857 that more subgoals may now be solved by simplification; potential
  1858 INCOMPATIBILITY.
  1859 
  1860 * Real: new type classes formalize real normed vector spaces and
  1861 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1862 and norm :: 'a => real.
  1863 
  1864 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1865 reals into other types. The overloaded constant Reals :: 'a set is now
  1866 defined as range of_real; potential INCOMPATIBILITY.
  1867 
  1868 * Real: proper support for ML code generation, including 'quickcheck'.
  1869 Reals are implemented as arbitrary precision rationals.
  1870 
  1871 * Hyperreal: Several constants that previously worked only for the
  1872 reals have been generalized, so they now work over arbitrary vector
  1873 spaces. Type annotations may need to be added in some cases; potential
  1874 INCOMPATIBILITY.
  1875 
  1876   Infinitesimal  :: ('a::real_normed_vector) star set
  1877   HFinite        :: ('a::real_normed_vector) star set
  1878   HInfinite      :: ('a::real_normed_vector) star set
  1879   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1880   monad          :: ('a::real_normed_vector) star => 'a star set
  1881   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1882   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1883   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1884   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1885   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1886   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1887   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1888   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1889   sgn            :: 'a::real_normed_vector => 'a
  1890   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1891 
  1892 * Complex: Some complex-specific constants are now abbreviations for
  1893 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1894 hnorm.  Other constants have been entirely removed in favor of the
  1895 polymorphic versions (INCOMPATIBILITY):
  1896 
  1897   approx        <-- capprox
  1898   HFinite       <-- CFinite
  1899   HInfinite     <-- CInfinite
  1900   Infinitesimal <-- CInfinitesimal
  1901   monad         <-- cmonad
  1902   galaxy        <-- cgalaxy
  1903   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1904   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1905   (ns)deriv     <-- (ns)cderiv
  1906 
  1907 
  1908 *** HOL-Algebra ***
  1909 
  1910 * Formalisation of ideals and the quotient construction over rings.
  1911 
  1912 * Order and lattice theory no longer based on records.
  1913 INCOMPATIBILITY.
  1914 
  1915 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1916 greatest_closed.  INCOMPATIBILITY.
  1917 
  1918 * Method algebra is now set up via an attribute.  For examples see
  1919 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1920 of algebraic structures.
  1921 
  1922 * Renamed theory CRing to Ring.
  1923 
  1924 
  1925 *** HOL-Nominal ***
  1926 
  1927 * Substantial, yet incomplete support for nominal datatypes (binding
  1928 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1929 src/HOL/Nominal/Examples.  Prospective users should consult
  1930 http://isabelle.in.tum.de/nominal/
  1931 
  1932 
  1933 *** ML ***
  1934 
  1935 * ML basics: just one true type int, which coincides with IntInf.int
  1936 (even on SML/NJ).
  1937 
  1938 * ML within Isar: antiquotations allow to embed statically-checked
  1939 formal entities in the source, referring to the context available at
  1940 compile-time.  For example:
  1941 
  1942 ML {* @{sort "{zero,one}"} *}
  1943 ML {* @{typ "'a => 'b"} *}
  1944 ML {* @{term "%x. x"} *}
  1945 ML {* @{prop "x == y"} *}
  1946 ML {* @{ctyp "'a => 'b"} *}
  1947 ML {* @{cterm "%x. x"} *}
  1948 ML {* @{cprop "x == y"} *}
  1949 ML {* @{thm asm_rl} *}
  1950 ML {* @{thms asm_rl} *}
  1951 ML {* @{type_name c} *}
  1952 ML {* @{type_syntax c} *}
  1953 ML {* @{const_name c} *}
  1954 ML {* @{const_syntax c} *}
  1955 ML {* @{context} *}
  1956 ML {* @{theory} *}
  1957 ML {* @{theory Pure} *}
  1958 ML {* @{theory_ref} *}
  1959 ML {* @{theory_ref Pure} *}
  1960 ML {* @{simpset} *}
  1961 ML {* @{claset} *}
  1962 ML {* @{clasimpset} *}
  1963 
  1964 The same works for sources being ``used'' within an Isar context.
  1965 
  1966 * ML in Isar: improved error reporting; extra verbosity with
  1967 ML_Context.trace enabled.
  1968 
  1969 * Pure/General/table.ML: the join operations now works via exceptions
  1970 DUP/SAME instead of type option. This is simpler in simple cases, and
  1971 admits slightly more efficient complex applications.
  1972 
  1973 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1974 use Context.generic instead of just theory.
  1975 
  1976 * Pure: datatype Context.generic joins theory/Proof.context and
  1977 provides some facilities for code that works in either kind of
  1978 context, notably GenericDataFun for uniform theory and proof data.
  1979 
  1980 * Pure: simplified internal attribute type, which is now always
  1981 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1982 local (Proof.context) attributes have been discontinued, while
  1983 minimizing code duplication. Thm.rule_attribute and
  1984 Thm.declaration_attribute build canonical attributes; see also structure
  1985 Context for further operations on Context.generic, notably
  1986 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1987 declarations and definitions.
  1988 
  1989 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1990 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1991 init only required for impure data. INCOMPATIBILITY: empty really need
  1992 to be empty (no dependencies on theory content!)
  1993 
  1994 * Pure/kernel: consts certification ignores sort constraints given in
  1995 signature declarations. (This information is not relevant to the
  1996 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1997 potential INCOMPATIBILITY.
  1998 
  1999 * Pure: axiomatic type classes are now purely definitional, with
  2000 explicit proofs of class axioms and super class relations performed
  2001 internally. See Pure/axclass.ML for the main internal interfaces --
  2002 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2003 AxClass.axiomatize_class/classrel/arity supersede
  2004 Sign.add_classes/classrel/arities.
  2005 
  2006 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2007 global/local versions on theory vs. Proof.context have been
  2008 discontinued; Attrib.syntax and Method.syntax have been adapted
  2009 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2010 attributes, methods, etc.
  2011 
  2012 * Pure: several functions of signature "... -> theory -> theory * ..."
  2013 have been reoriented to "... -> theory -> ... * theory" in order to
  2014 allow natural usage in combination with the ||>, ||>>, |-> and
  2015 fold_map combinators.
  2016 
  2017 * Pure: official theorem names (closed derivations) and additional
  2018 comments (tags) are now strictly separate.  Name hints -- which are
  2019 maintained as tags -- may be attached any time without affecting the
  2020 derivation.
  2021 
  2022 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2023 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2024 achieve the old behaviour.
  2025 
  2026 * Pure: the "Goal" constant is now called "prop", supporting a
  2027 slightly more general idea of ``protecting'' meta-level rule
  2028 statements.
  2029 
  2030 * Pure: Logic.(un)varify only works in a global context, which is now
  2031 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2032 Logic.legacy_(un)varify as temporary workaround.
  2033 
  2034 * Pure: structure Name provides scalable operations for generating
  2035 internal variable names, notably Name.variants etc.  This replaces
  2036 some popular functions from term.ML:
  2037 
  2038   Term.variant		->  Name.variant
  2039   Term.variantlist	->  Name.variant_list
  2040   Term.invent_names	->  Name.invent_list
  2041 
  2042 Note that low-level renaming rarely occurs in new code -- operations
  2043 from structure Variable are used instead (see below).
  2044 
  2045 * Pure: structure Variable provides fundamental operations for proper
  2046 treatment of fixed/schematic variables in a context.  For example,
  2047 Variable.import introduces fixes for schematics of given facts and
  2048 Variable.export reverses the effect (up to renaming) -- this replaces
  2049 various freeze_thaw operations.
  2050 
  2051 * Pure: structure Goal provides simple interfaces for
  2052 init/conclude/finish and tactical prove operations (replacing former
  2053 Tactic.prove).  Goal.prove is the canonical way to prove results
  2054 within a given context; Goal.prove_global is a degraded version for
  2055 theory level goals, including a global Drule.standard.  Note that
  2056 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2057 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2058 in a locale context).
  2059 
  2060 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2061 and type checking (Syntax.check_term etc.), with common combinations
  2062 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2063 which are considered legacy and await removal.
  2064 
  2065 * Pure/Syntax: generic interfaces for type unchecking
  2066 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2067 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2068 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2069 available for convenience, but refer to the very same operations using
  2070 a mere theory instead of a full context.
  2071 
  2072 * Isar: simplified treatment of user-level errors, using exception
  2073 ERROR of string uniformly.  Function error now merely raises ERROR,
  2074 without any side effect on output channels.  The Isar toplevel takes
  2075 care of proper display of ERROR exceptions.  ML code may use plain
  2076 handle/can/try; cat_error may be used to concatenate errors like this:
  2077 
  2078   ... handle ERROR msg => cat_error msg "..."
  2079 
  2080 Toplevel ML code (run directly or through the Isar toplevel) may be
  2081 embedded into the Isar toplevel with exception display/debug like
  2082 this:
  2083 
  2084   Isar.toplevel (fn () => ...)
  2085 
  2086 INCOMPATIBILITY, removed special transform_error facilities, removed
  2087 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2088 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2089 -- use plain ERROR instead.
  2090 
  2091 * Isar: theory setup now has type (theory -> theory), instead of a
  2092 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2093 
  2094 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2095 ProofContext.debug/verbose flags.
  2096 
  2097 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2098 theory before entering a proof state.  Transactions now always see a
  2099 quasi-functional intermediate checkpoint, both in interactive and
  2100 batch mode.
  2101 
  2102 * Isar: simplified interfaces for outer syntax.  Renamed
  2103 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2104 OuterSyntax.add_parsers -- this functionality is now included in
  2105 OuterSyntax.command etc.  INCOMPATIBILITY.
  2106 
  2107 * Simplifier: the simpset of a running simplification process now
  2108 contains a proof context (cf. Simplifier.the_context), which is the
  2109 very context that the initial simpset has been retrieved from (by
  2110 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2111 (solver, looper etc.) may depend on arbitrary proof data.
  2112 
  2113 * Simplifier.inherit_context inherits the proof context (plus the
  2114 local bounds) of the current simplification process; any simproc
  2115 etc. that calls the Simplifier recursively should do this!  Removed
  2116 former Simplifier.inherit_bounds, which is already included here --
  2117 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2118 specify an explicit context using Simplifier.context/theory_context.
  2119 
  2120 * Simplifier/Classical Reasoner: more abstract interfaces
  2121 change_simpset/claset for modifying the simpset/claset reference of a
  2122 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2123 INCOMPATIBILITY.
  2124 
  2125 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2126 "Trueprop" etc.
  2127 
  2128 
  2129 *** System ***
  2130 
  2131 * settings: the default heap location within ISABELLE_HOME_USER now
  2132 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2133 Isabelle installations.
  2134 
  2135 * isabelle-process: option -S (secure mode) disables some critical
  2136 operations, notably runtime compilation and evaluation of ML source
  2137 code.
  2138 
  2139 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2140 
  2141 * Support for parallel execution, using native multicore support of
  2142 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2143 independent theories, according to the given theory header
  2144 specifications. The maximum number of worker threads is specified via
  2145 usedir option -M or the "max-threads" setting in Proof General. A
  2146 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2147 to 6 on a 8-core machine.  User-code needs to observe certain
  2148 guidelines for thread-safe programming, see appendix A in the Isar
  2149 Implementation manual.
  2150 
  2151 
  2152 
  2153 New in Isabelle2005 (October 2005)
  2154 ----------------------------------
  2155 
  2156 *** General ***
  2157 
  2158 * Theory headers: the new header syntax for Isar theories is
  2159 
  2160   theory <name>
  2161   imports <theory1> ... <theoryN>
  2162   uses <file1> ... <fileM>
  2163   begin
  2164 
  2165 where the 'uses' part is optional.  The previous syntax
  2166 
  2167   theory <name> = <theory1> + ... + <theoryN>:
  2168 
  2169 will disappear in the next release.  Use isatool fixheaders to convert
  2170 existing theory files.  Note that there is no change in ancient
  2171 non-Isar theories now, but these will disappear soon.
  2172 
  2173 * Theory loader: parent theories can now also be referred to via
  2174 relative and absolute paths.
  2175 
  2176 * Command 'find_theorems' searches for a list of criteria instead of a
  2177 list of constants. Known criteria are: intro, elim, dest, name:string,
  2178 simp:term, and any term. Criteria can be preceded by '-' to select
  2179 theorems that do not match. Intro, elim, dest select theorems that
  2180 match the current goal, name:s selects theorems whose fully qualified
  2181 name contain s, and simp:term selects all simplification rules whose
  2182 lhs match term.  Any other term is interpreted as pattern and selects
  2183 all theorems matching the pattern. Available in ProofGeneral under
  2184 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2185 
  2186   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2187 
  2188 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2189 matching the current goal as introduction rule and not having "HOL."
  2190 in their name (i.e. not being defined in theory HOL).
  2191 
  2192 * Command 'thms_containing' has been discontinued in favour of
  2193 'find_theorems'; INCOMPATIBILITY.
  2194 
  2195 * Communication with Proof General is now 8bit clean, which means that
  2196 Unicode text in UTF-8 encoding may be used within theory texts (both
  2197 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2198 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2199 
  2200   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2201   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2202 
  2203 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2204 Classical Reasoner.  Typical big applications run around 2 times
  2205 faster.
  2206 
  2207 
  2208 *** Document preparation ***
  2209 
  2210 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2211 of raw sources.  Only those symbols that do not require additional
  2212 LaTeX packages (depending on comments in isabellesym.sty) are
  2213 displayed properly, everything else is left verbatim.  isatool display
  2214 and isatool print are used as front ends (these are subject to the
  2215 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2216 
  2217 * Command tags control specific markup of certain regions of text,
  2218 notably folding and hiding.  Predefined tags include "theory" (for
  2219 theory begin and end), "proof" for proof commands, and "ML" for
  2220 commands involving ML code; the additional tags "visible" and
  2221 "invisible" are unused by default.  Users may give explicit tag
  2222 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2223 interpretation of tags is determined by the LaTeX job during document
  2224 preparation: see option -V of isatool usedir, or options -n and -t of
  2225 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2226 \isadroptag.
  2227 
  2228 Several document versions may be produced at the same time via isatool
  2229 usedir (the generated index.html will link all of them).  Typical
  2230 specifications include ''-V document=theory,proof,ML'' to present
  2231 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2232 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2233 these parts without any formal replacement text.  The Isabelle site
  2234 default settings produce ''document'' and ''outline'' versions as
  2235 specified above.
  2236 
  2237 * Several new antiquotations:
  2238 
  2239   @{term_type term} prints a term with its type annotated;
  2240 
  2241   @{typeof term} prints the type of a term;
  2242 
  2243   @{const const} is the same as @{term const}, but checks that the
  2244   argument is a known logical constant;
  2245 
  2246   @{term_style style term} and @{thm_style style thm} print a term or
  2247   theorem applying a "style" to it
  2248 
  2249   @{ML text}
  2250 
  2251 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2252 definitions, equations, inequations etc., 'concl' printing only the
  2253 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2254 to print the specified premise.  TermStyle.add_style provides an ML
  2255 interface for introducing further styles.  See also the "LaTeX Sugar"
  2256 document practical applications.  The ML antiquotation prints
  2257 type-checked ML expressions verbatim.
  2258 
  2259 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2260 and 'text' support optional locale specification '(in loc)', which
  2261 specifies the default context for interpreting antiquotations.  For
  2262 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2263 
  2264 * Option 'locale=NAME' of antiquotations specifies an alternative
  2265 context interpreting the subsequent argument.  For example: @{thm
  2266 [locale=lattice] inf_assoc}.
  2267 
  2268 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2269 a proof context.
  2270 
  2271 * Proper output of antiquotations for theory commands involving a
  2272 proof context (such as 'locale' or 'theorem (in loc) ...').
  2273 
  2274 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2275 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2276 
  2277 * isatool usedir: new option -C (default true) controls whether option
  2278 -D should include a copy of the original document directory; -C false
  2279 prevents unwanted effects such as copying of administrative CVS data.
  2280 
  2281 
  2282 *** Pure ***
  2283 
  2284 * Considerably improved version of 'constdefs' command.  Now performs
  2285 automatic type-inference of declared constants; additional support for
  2286 local structure declarations (cf. locales and HOL records), see also
  2287 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2288 sequential dependencies of definitions within a single 'constdefs'
  2289 section; moreover, the declared name needs to be an identifier.  If
  2290 all fails, consider to fall back on 'consts' and 'defs' separately.
  2291 
  2292 * Improved indexed syntax and implicit structures.  First of all,
  2293 indexed syntax provides a notational device for subscripted
  2294 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2295 expressions.  Secondly, in a local context with structure
  2296 declarations, number indexes \<^sub>n or the empty index (default
  2297 number 1) refer to a certain fixed variable implicitly; option
  2298 show_structs controls printing of implicit structures.  Typical
  2299 applications of these concepts involve record types and locales.
  2300 
  2301 * New command 'no_syntax' removes grammar declarations (and
  2302 translations) resulting from the given syntax specification, which is
  2303 interpreted in the same manner as for the 'syntax' command.
  2304 
  2305 * 'Advanced' translation functions (parse_translation etc.) may depend
  2306 on the signature of the theory context being presently used for
  2307 parsing/printing, see also isar-ref manual.
  2308 
  2309 * Improved 'oracle' command provides a type-safe interface to turn an
  2310 ML expression of type theory -> T -> term into a primitive rule of
  2311 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2312 is already included here); see also FOL/ex/IffExample.thy;
  2313 INCOMPATIBILITY.
  2314 
  2315 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2316 before); "cI" is no longer bound, use "c.intro" instead.
  2317 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2318 axclasses vs. locales.
  2319 
  2320 * Improved internal renaming of symbolic identifiers -- attach primes
  2321 instead of base 26 numbers.
  2322 
  2323 * New flag show_question_marks controls printing of leading question
  2324 marks in schematic variable names.
  2325 
  2326 * In schematic variable names, *any* symbol following \<^isub> or
  2327 \<^isup> is now treated as part of the base name.  For example, the
  2328 following works without printing of awkward ".0" indexes:
  2329 
  2330   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2331     by simp
  2332 
  2333 * Inner syntax includes (*(*nested*) comments*).
  2334 
  2335 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2336 annotations as "(00...)".
  2337 
  2338 * Clear separation of logical types and nonterminals, where the latter
  2339 may only occur in 'syntax' specifications or type abbreviations.
  2340 Before that distinction was only partially implemented via type class
  2341 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2342 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2343 exotic syntax specifications may require further adaption
  2344 (e.g. Cube/Cube.thy).
  2345 
  2346 * Removed obsolete type class "logic", use the top sort {} instead.
  2347 Note that non-logical types should be declared as 'nonterminals'
  2348 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2349 specifications.
  2350 
  2351 * Attributes 'induct' and 'cases': type or set names may now be
  2352 locally fixed variables as well.
  2353 
  2354 * Simplifier: can now control the depth to which conditional rewriting
  2355 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2356 Limit.
  2357 
  2358 * Simplifier: simplification procedures may now take the current
  2359 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2360 interface), which is very useful for calling the Simplifier
  2361 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2362 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2363 low-level mk_simproc no longer applies Logic.varify internally, to
  2364 allow for use in a context of fixed variables.
  2365 
  2366 * thin_tac now works even if the assumption being deleted contains !!
  2367 or ==>.  More generally, erule now works even if the major premise of
  2368 the elimination rule contains !! or ==>.
  2369 
  2370 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2371 
  2372 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2373 from Pure, which contains all common declarations already.  Both
  2374 theories are defined via plain Isabelle/Isar .thy files.
  2375 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2376 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2377 use isatool fixcpure to adapt your theory and ML sources.
  2378 
  2379 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2380 selections of theorems in named facts via index ranges.
  2381 
  2382 * 'print_theorems': in theory mode, really print the difference
  2383 wrt. the last state (works for interactive theory development only),
  2384 in proof mode print all local facts (cf. 'print_facts');
  2385 
  2386 * 'hide': option '(open)' hides only base names.
  2387 
  2388 * More efficient treatment of intermediate checkpoints in interactive
  2389 theory development.
  2390 
  2391 * Code generator is now invoked via code_module (incremental code
  2392 generation) and code_library (modular code generation, ML structures
  2393 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2394 must be quoted when used as identifiers.
  2395 
  2396 * New 'value' command for reading, evaluating and printing terms using
  2397 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2398 quoted when used as identifier.
  2399 
  2400 
  2401 *** Locales ***
  2402 
  2403 * New commands for the interpretation of locale expressions in
  2404 theories (1), locales (2) and proof contexts (3).  These generate
  2405 proof obligations from the expression specification.  After the
  2406 obligations have been discharged, theorems of the expression are added
  2407 to the theory, target locale or proof context.  The synopsis of the
  2408 commands is a follows:
  2409 
  2410   (1) interpretation expr inst
  2411   (2) interpretation target < expr
  2412   (3) interpret expr inst
  2413 
  2414 Interpretation in theories and proof contexts require a parameter
  2415 instantiation of terms from the current context.  This is applied to
  2416 specifications and theorems of the interpreted expression.
  2417 Interpretation in locales only permits parameter renaming through the
  2418 locale expression.  Interpretation is smart in that interpretations
  2419 that are active already do not occur in proof obligations, neither are
  2420 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2421 inspect active interpretations of a particular locale.  For details,
  2422 see the Isar Reference manual.  Examples can be found in
  2423 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2424 
  2425 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2426 'interpret' instead.
  2427 
  2428 * New context element 'constrains' for adding type constraints to
  2429 parameters.
  2430 
  2431 * Context expressions: renaming of parameters with syntax
  2432 redeclaration.
  2433 
  2434 * Locale declaration: 'includes' disallowed.
  2435 
  2436 * Proper static binding of attribute syntax -- i.e. types / terms /
  2437 facts mentioned as arguments are always those of the locale definition
  2438 context, independently of the context of later invocations.  Moreover,
  2439 locale operations (renaming and type / term instantiation) are applied
  2440 to attribute arguments as expected.
  2441 
  2442 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2443 actual attributes; rare situations may require Attrib.attribute to
  2444 embed those attributes into Attrib.src that lack concrete syntax.
  2445 Attribute implementations need to cooperate properly with the static
  2446 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2447 Attrib.XXX_thm etc. already do the right thing without further
  2448 intervention.  Only unusual applications -- such as "where" or "of"
  2449 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2450 on the context and the facts involved -- may have to assign parsed
  2451 values to argument tokens explicitly.
  2452 
  2453 * Changed parameter management in theorem generation for long goal
  2454 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2455 theorem statement in rare situations.
  2456 
  2457 * Locale inspection command 'print_locale' omits notes elements.  Use
  2458 'print_locale!' to have them included in the output.
  2459 
  2460 
  2461 *** Provers ***
  2462 
  2463 * Provers/hypsubst.ML: improved version of the subst method, for
  2464 single-step rewriting: it now works in bound variable contexts. New is
  2465 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2466 rewrite a different subterm than the original subst method, which is
  2467 still available as 'simplesubst'.
  2468 
  2469 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2470 and quasi orders.
  2471 
  2472 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2473 reflexive-transitive closure of relations.
  2474 
  2475 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2476 limit (previously hard-coded with a value of 20) user-definable.
  2477 
  2478 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2479 is peformed already.  Object-logics merely need to finish their
  2480 initial simpset configuration as before.  INCOMPATIBILITY.
  2481 
  2482 
  2483 *** HOL ***
  2484 
  2485 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2486 
  2487   syntax (epsilon)
  2488     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2489 
  2490 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2491 and x-symbol; use option '-m epsilon' to get it actually printed.
  2492 Moreover, the mathematically important symbolic identifier \<epsilon>
  2493 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2494 
  2495 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2496 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2497 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2498 support corresponding Isar calculations.
  2499 
  2500 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2501 instead of ":".
  2502 
  2503 * theory SetInterval: changed the syntax for open intervals:
  2504 
  2505   Old       New
  2506   {..n(}    {..<n}
  2507   {)n..}    {n<..}
  2508   {m..n(}   {m..<n}
  2509   {)m..n}   {m<..n}
  2510   {)m..n(}  {m<..<n}
  2511 
  2512 The old syntax is still supported but will disappear in the next
  2513 release.  For conversion use the following Emacs search and replace
  2514 patterns (these are not perfect but work quite well):
  2515 
  2516   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2517   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2518 
  2519 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2520 equalities in commutative rings; method 'algebra' provides a generic
  2521 interface.
  2522 
  2523 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2524 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2525 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2526 be a tuple pattern.
  2527 
  2528 Some new syntax forms are available:
  2529 
  2530   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2531   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2532   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2533   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2534 
  2535 The latter form "\<Sum>x < k. e" used to be based on a separate
  2536 function "Summation", which has been discontinued.
  2537 
  2538 * theory Finite_Set: in structured induction proofs, the insert case
  2539 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2540 (insert F x)'.
  2541 
  2542 * The 'refute' command has been extended to support a much larger
  2543 fragment of HOL, including axiomatic type classes, constdefs and
  2544 typedefs, inductive datatypes and recursion.
  2545 
  2546 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2547 Requires zChaff with proof generation to be installed.  See
  2548 HOL/ex/SAT_Examples.thy for examples.
  2549 
  2550 * Datatype induction via method 'induct' now preserves the name of the
  2551 induction variable. For example, when proving P(xs::'a list) by
  2552 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2553 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2554 in unstructured proof scripts.
  2555 
  2556 * Reworked implementation of records.  Improved scalability for
  2557 records with many fields, avoiding performance problems for type
  2558 inference. Records are no longer composed of nested field types, but
  2559 of nested extension types. Therefore the record type only grows linear
  2560 in the number of extensions and not in the number of fields.  The
  2561 top-level (users) view on records is preserved.  Potential
  2562 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2563 old record representation. The type generated for a record is called
  2564 <record_name>_ext_type.
  2565 
  2566 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2567 proofs triggered by a record definition or a simproc (if
  2568 quick_and_dirty is enabled).  Definitions of large records can take
  2569 quite long.
  2570 
  2571 New simproc record_upd_simproc for simplification of multiple record
  2572 updates enabled by default.  Moreover, trivial updates are also
  2573 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2574 occasionally, since simplification is more powerful by default.
  2575 
  2576 * typedef: proper support for polymorphic sets, which contain extra
  2577 type-variables in the term.
  2578 
  2579 * Simplifier: automatically reasons about transitivity chains
  2580 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2581 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2582 old proofs break occasionally as simplification may now solve more
  2583 goals than previously.
  2584 
  2585 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2586 present.  Works for all partial orders (class "order"), in particular
  2587 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2588 just like y <= x.
  2589 
  2590 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2591 bound variable or a constant then the let is unfolded.  Otherwise
  2592 first a is simplified to b, and then f b is simplified to g. If
  2593 possible we abstract b from g arriving at "let x = b in h x",
  2594 otherwise we unfold the let and arrive at g.  The simproc can be
  2595 enabled/disabled by the reference use_let_simproc.  Potential
  2596 INCOMPATIBILITY since simplification is more powerful by default.
  2597 
  2598 * Classical reasoning: the meson method now accepts theorems as arguments.
  2599 
  2600 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2601 jobs to provide advice on the provability of subgoals.
  2602 
  2603 * Theory OrderedGroup and Ring_and_Field: various additions and
  2604 improvements to faciliate calculations involving equalities and
  2605 inequalities.
  2606 
  2607 The following theorems have been eliminated or modified
  2608 (INCOMPATIBILITY):
  2609 
  2610   abs_eq             now named abs_of_nonneg
  2611   abs_of_ge_0        now named abs_of_nonneg
  2612   abs_minus_eq       now named abs_of_nonpos
  2613   imp_abs_id         now named abs_of_nonneg
  2614   imp_abs_neg_id     now named abs_of_nonpos
  2615   mult_pos           now named mult_pos_pos
  2616   mult_pos_le        now named mult_nonneg_nonneg
  2617   mult_pos_neg_le    now named mult_nonneg_nonpos
  2618   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2619   mult_neg           now named mult_neg_neg
  2620   mult_neg_le        now named mult_nonpos_nonpos
  2621 
  2622 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2623      
  2624      zero_le_square
  2625      not_square_less_zero 
  2626 
  2627   The following lemmas have been deleted from Real/RealPow:
  2628   
  2629      realpow_zero_zero
  2630      realpow_two
  2631      realpow_less
  2632      zero_le_power
  2633      realpow_two_le
  2634      abs_realpow_two
  2635      realpow_two_abs     
  2636 
  2637 * Theory Parity: added rules for simplifying exponents.
  2638 
  2639 * Theory List:
  2640 
  2641 The following theorems have been eliminated or modified
  2642 (INCOMPATIBILITY):
  2643 
  2644   list_all_Nil       now named list_all.simps(1)
  2645   list_all_Cons      now named list_all.simps(2)
  2646   list_all_conv      now named list_all_iff
  2647   set_mem_eq         now named mem_iff
  2648 
  2649 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2650 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2651 
  2652 
  2653 *** HOL-Complex ***
  2654 
  2655 * Theory RealDef: better support for embedding natural numbers and
  2656 integers in the reals.
  2657 
  2658 The following theorems have been eliminated or modified
  2659 (INCOMPATIBILITY):
  2660 
  2661   exp_ge_add_one_self  now requires no hypotheses
  2662   real_of_int_add      reversed direction of equality (use [symmetric])
  2663   real_of_int_minus    reversed direction of equality (use [symmetric])
  2664   real_of_int_diff     reversed direction of equality (use [symmetric])
  2665   real_of_int_mult     reversed direction of equality (use [symmetric])
  2666 
  2667 * Theory RComplete: expanded support for floor and ceiling functions.
  2668 
  2669 * Theory Ln is new, with properties of the natural logarithm
  2670 
  2671 * Hyperreal: There is a new type constructor "star" for making
  2672 nonstandard types.  The old type names are now type synonyms:
  2673 
  2674   hypreal = real star
  2675   hypnat = nat star
  2676   hcomplex = complex star
  2677 
  2678 * Hyperreal: Many groups of similarly-defined constants have been
  2679 replaced by polymorphic versions (INCOMPATIBILITY):
  2680 
  2681   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2682 
  2683   starset      <-- starsetNat, starsetC
  2684   *s*          <-- *sNat*, *sc*
  2685   starset_n    <-- starsetNat_n, starsetC_n
  2686   *sn*         <-- *sNatn*, *scn*
  2687   InternalSets <-- InternalNatSets, InternalCSets
  2688 
  2689   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2690   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2691   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2692   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2693   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2694 
  2695 * Hyperreal: Many type-specific theorems have been removed in favor of
  2696 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2697 
  2698   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2699   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2700   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2701   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2702   right_minus <-- hypreal_add_minus
  2703   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2704   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2705   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2706   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2707   mult_1_right <-- hcomplex_mult_one_right
  2708   mult_zero_left <-- hcomplex_mult_zero_left
  2709   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2710   right_distrib <-- hypnat_add_mult_distrib2
  2711   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2712   right_inverse <-- hypreal_mult_inverse
  2713   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2714   order_refl <-- {hypreal,hypnat}_le_refl
  2715   order_trans <-- {hypreal,hypnat}_le_trans
  2716   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2717   order_less_le <-- {hypreal,hypnat}_less_le
  2718   linorder_linear <-- {hypreal,hypnat}_le_linear
  2719   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2720   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2721   add_nonneg_nonneg <-- hypreal_le_add_order
  2722 
  2723 * Hyperreal: Separate theorems having to do with type-specific
  2724 versions of constants have been merged into theorems that apply to the
  2725 new polymorphic constants (INCOMPATIBILITY):
  2726 
  2727   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2728   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2729   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2730   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2731   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2732   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2733   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2734   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2735   STAR_diff <-- {STAR,STARC}_diff
  2736   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2737     STARC_hcomplex_of_complex}_image_subset
  2738   starset_n_Un <-- starset{Nat,C}_n_Un
  2739   starset_n_Int <-- starset{Nat,C}_n_Int
  2740   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2741   starset_n_diff <-- starset{Nat,C}_n_diff
  2742   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2743   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2744   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2745   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2746   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2747   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2748   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2749   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2750   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2751   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2752   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2753   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2754   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2755   starfun_diff <-- starfun{C,RC,CR}_diff
  2756   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2757   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2758   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2759   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2760   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2761   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2762   starfun_Id <-- starfunC_Id
  2763   starfun_approx <-- starfun{Nat,CR}_approx
  2764   starfun_capprox <-- starfun{C,RC}_capprox
  2765   starfun_abs <-- starfunNat_rabs
  2766   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2767   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2768   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2769   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2770   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2771   starfun_add_approx <-- starfunCR_add_approx
  2772   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2773   starfun_divide <-- starfun{C,CR,RC}_divide
  2774   starfun_n <-- starfun{Nat,C}_n
  2775   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2776   starfun_n_add <-- starfun{Nat,C}_n_add
  2777   starfun_n_add_minus <-- starfunNat_n_add_minus
  2778   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2779   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2780   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2781 
  2782   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2783   star_n_minus <-- {hypreal,hcomplex}_minus
  2784   star_n_diff <-- {hypreal,hcomplex}_diff
  2785   star_n_mult <-- {hypreal,hcomplex}_mult
  2786   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2787   star_n_le <-- {hypreal,hypnat}_le
  2788   star_n_less <-- {hypreal,hypnat}_less
  2789   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2790   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2791   star_n_abs <-- hypreal_hrabs
  2792   star_n_divide <-- hcomplex_divide
  2793 
  2794   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2795   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2796   star_of_diff <-- hypreal_of_real_diff
  2797   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2798   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2799   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2800   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2801   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2802   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2803   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2804   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2805   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2806   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2807   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2808   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2809   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2810   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2811   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2812   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2813   star_of_power <-- hypreal_of_real_power
  2814   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2815 
  2816 * Hyperreal: new method "transfer" that implements the transfer
  2817 principle of nonstandard analysis. With a subgoal that mentions
  2818 nonstandard types like "'a star", the command "apply transfer"
  2819 replaces it with an equivalent one that mentions only standard types.
  2820 To be successful, all free variables must have standard types; non-
  2821 standard variables must have explicit universal quantifiers.
  2822 
  2823 * Hyperreal: A theory of Taylor series.
  2824 
  2825 
  2826 *** HOLCF ***
  2827 
  2828 * Discontinued special version of 'constdefs' (which used to support
  2829 continuous functions) in favor of the general Pure one with full
  2830 type-inference.
  2831 
  2832 * New simplification procedure for solving continuity conditions; it
  2833 is much faster on terms with many nested lambda abstractions (cubic
  2834 instead of exponential time).
  2835 
  2836 * New syntax for domain package: selector names are now optional.
  2837 Parentheses should be omitted unless argument is lazy, for example:
  2838 
  2839   domain 'a stream = cons "'a" (lazy "'a stream")
  2840 
  2841 * New command 'fixrec' for defining recursive functions with pattern
  2842 matching; defining multiple functions with mutual recursion is also
  2843 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2844 sinr, or any data constructor defined by the domain package. The given
  2845 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2846 syntax and examples.
  2847 
  2848 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2849 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2850 but the proof obligation additionally includes an admissibility
  2851 requirement. The packages generate instances of class cpo or pcpo,
  2852 with continuity and strictness theorems for Rep and Abs.
  2853 
  2854 * HOLCF: Many theorems have been renamed according to a more standard naming
  2855 scheme (INCOMPATIBILITY):
  2856 
  2857   foo_inject:  "foo$x = foo$y ==> x = y"
  2858   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2859   foo_less:    "(foo$x << foo$y) = (x << y)"
  2860   foo_strict:  "foo$UU = UU"
  2861   foo_defined: "... ==> foo$x ~= UU"
  2862   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2863 
  2864 
  2865 *** ZF ***
  2866 
  2867 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2868 including the First Isomorphism Theorem (on quotienting by the kernel
  2869 of a homomorphism).
  2870 
  2871 * ZF/Simplifier: install second copy of type solver that actually
  2872 makes use of TC rules declared to Isar proof contexts (or locales);
  2873 the old version is still required for ML proof scripts.
  2874 
  2875 
  2876 *** Cube ***
  2877 
  2878 * Converted to Isar theory format; use locales instead of axiomatic
  2879 theories.
  2880 
  2881 
  2882 *** ML ***
  2883 
  2884 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2885 for ||>, ||>>, |>>,
  2886 
  2887 * Pure/library.ML no longer defines its own option datatype, but uses
  2888 that of the SML basis, which has constructors NONE and SOME instead of
  2889 None and Some, as well as exception Option.Option instead of OPTION.
  2890 The functions the, if_none, is_some, is_none have been adapted
  2891 accordingly, while Option.map replaces apsome.
  2892 
  2893 * Pure/library.ML: the exception LIST has been given up in favour of
  2894 the standard exceptions Empty and Subscript, as well as
  2895 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2896 superceded by the standard hd and tl functions etc.
  2897 
  2898 A number of basic list functions are no longer exported to the ML
  2899 toplevel, as they are variants of predefined functions.  The following
  2900 suggests how one can translate existing code:
  2901 
  2902     rev_append xs ys = List.revAppend (xs, ys)
  2903     nth_elem (i, xs) = List.nth (xs, i)
  2904     last_elem xs = List.last xs
  2905     flat xss = List.concat xss
  2906     seq fs = List.app fs
  2907     partition P xs = List.partition P xs
  2908     mapfilter f xs = List.mapPartial f xs
  2909 
  2910 * Pure/library.ML: several combinators for linear functional
  2911 transformations, notably reverse application and composition:
  2912 
  2913   x |> f                f #> g
  2914   (x, y) |-> f          f #-> g
  2915 
  2916 * Pure/library.ML: introduced/changed precedence of infix operators:
  2917 
  2918   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2919   infix 2 ?;
  2920   infix 3 o oo ooo oooo;
  2921   infix 4 ~~ upto downto;
  2922 
  2923 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2924 infix operators.
  2925 
  2926 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2927 fold_map support linear functional transformations and nesting.  For
  2928 example:
  2929 
  2930   fold f [x1, ..., xN] y =
  2931     y |> f x1 |> ... |> f xN
  2932 
  2933   (fold o fold) f [xs1, ..., xsN] y =
  2934     y |> fold f xs1 |> ... |> fold f xsN
  2935 
  2936   fold f [x1, ..., xN] =
  2937     f x1 #> ... #> f xN
  2938 
  2939   (fold o fold) f [xs1, ..., xsN] =
  2940     fold f xs1 #> ... #> fold f xsN
  2941 
  2942 * Pure/library.ML: the following selectors on type 'a option are
  2943 available:
  2944 
  2945   the:               'a option -> 'a  (*partial*)
  2946   these:             'a option -> 'a  where 'a = 'b list
  2947   the_default: 'a -> 'a option -> 'a
  2948   the_list:          'a option -> 'a list
  2949 
  2950 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2951 basic operations for association lists, following natural argument
  2952 order; moreover the explicit equality predicate passed here avoids
  2953 potentially expensive polymorphic runtime equality checks.
  2954 The old functions may be expressed as follows:
  2955 
  2956   assoc = uncurry (AList.lookup (op =))
  2957   assocs = these oo AList.lookup (op =)
  2958   overwrite = uncurry (AList.update (op =)) o swap
  2959 
  2960 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2961 
  2962   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2963   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2964 
  2965 replacing make_keylist and keyfilter (occassionally used)
  2966 Naive rewrites:
  2967 
  2968   make_keylist = AList.make
  2969   keyfilter = AList.find (op =)
  2970 
  2971 * eq_fst and eq_snd now take explicit equality parameter, thus
  2972   avoiding eqtypes. Naive rewrites:
  2973 
  2974     eq_fst = eq_fst (op =)
  2975     eq_snd = eq_snd (op =)
  2976 
  2977 * Removed deprecated apl and apr (rarely used).
  2978   Naive rewrites:
  2979 
  2980     apl (n, op) =>>= curry op n
  2981     apr (op, m) =>>= fn n => op (n, m)
  2982 
  2983 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2984 provides a reasonably efficient light-weight implementation of sets as
  2985 lists.
  2986 
  2987 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2988 few new operations; existing lookup and update are now curried to
  2989 follow natural argument order (for use with fold etc.);
  2990 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2991 
  2992 * Pure/General: output via the Isabelle channels of
  2993 writeln/warning/error etc. is now passed through Output.output, with a
  2994 hook for arbitrary transformations depending on the print_mode
  2995 (cf. Output.add_mode -- the first active mode that provides a output
  2996 function wins).  Already formatted output may be embedded into further
  2997 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2998 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2999 accommodate easy composition of diagnostic messages etc.  Programmers
  3000 rarely need to care about Output.output or Output.raw at all, with
  3001 some notable exceptions: Output.output is required when bypassing the
  3002 standard channels (writeln etc.), or in token translations to produce
  3003 properly formatted results; Output.raw is required when capturing
  3004 already output material that will eventually be presented to the user
  3005 a second time.  For the default print mode, both Output.output and
  3006 Output.raw have no effect.
  3007 
  3008 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3009 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3010 cumulative results are displayed at the end of a batch session.
  3011 
  3012 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3013 replaced by File.platform_path and File.shell_path (with appropriate
  3014 hooks).  This provides a clean interface for unusual systems where the
  3015 internal and external process view of file names are different.
  3016 
  3017 * Pure: more efficient orders for basic syntactic entities: added
  3018 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3019 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3020 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3021 orders now -- potential INCOMPATIBILITY for code that depends on a
  3022 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3023 Library.sort_strings on result).
  3024 
  3025 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3026 fold_types traverse types/terms from left to right, observing natural
  3027 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3028 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3029 
  3030 * Pure: name spaces have been refined, with significant changes of the
  3031 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3032 to extern(_table).  The plain name entry path is superceded by a
  3033 general 'naming' context, which also includes the 'policy' to produce
  3034 a fully qualified name and external accesses of a fully qualified
  3035 name; NameSpace.extend is superceded by context dependent
  3036 Sign.declare_name.  Several theory and proof context operations modify
  3037 the naming context.  Especially note Theory.restore_naming and
  3038 ProofContext.restore_naming to get back to a sane state; note that
  3039 Theory.add_path is no longer sufficient to recover from
  3040 Theory.absolute_path in particular.
  3041 
  3042 * Pure: new flags short_names (default false) and unique_names
  3043 (default true) for controlling output of qualified names.  If
  3044 short_names is set, names are printed unqualified.  If unique_names is
  3045 reset, the name prefix is reduced to the minimum required to achieve
  3046 the original result when interning again, even if there is an overlap
  3047 with earlier declarations.
  3048 
  3049 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3050 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3051 (useful for printing error messages).  INCOMPATIBILITY.
  3052 
  3053 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3054 Theory.theory are now identified, referring to the universal
  3055 Context.theory (see Pure/context.ML).  Actual signature and theory
  3056 content is managed as theory data.  The old code and interfaces were
  3057 spread over many files and structures; the new arrangement introduces
  3058 considerable INCOMPATIBILITY to gain more clarity:
  3059 
  3060   Context -- theory management operations (name, identity, inclusion,
  3061     parents, ancestors, merge, etc.), plus generic theory data;
  3062 
  3063   Sign -- logical signature and syntax operations (declaring consts,
  3064     types, etc.), plus certify/read for common entities;
  3065 
  3066   Theory -- logical theory operations (stating axioms, definitions,
  3067     oracles), plus a copy of logical signature operations (consts,
  3068     types, etc.); also a few basic management operations (Theory.copy,
  3069     Theory.merge, etc.)
  3070 
  3071 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3072 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3073 for convenience -- they merely return the theory.
  3074 
  3075 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3076 
  3077 * Pure: the Isar proof context type is already defined early in Pure
  3078 as Context.proof (note that ProofContext.context and Proof.context are
  3079 aliases, where the latter is the preferred name).  This enables other
  3080 Isabelle components to refer to that type even before Isar is present.
  3081 
  3082 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3083 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3084 any of these kinds.  For example, Sign.intern typeK is now
  3085 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3086 Theory.hide_types.  Also note that former
  3087 Theory.hide_classes/types/consts are now
  3088 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3089 internalize their arguments!  INCOMPATIBILITY.
  3090 
  3091 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3092 datatype thmref (with constructors Name and NameSelection) instead of
  3093 plain string -- INCOMPATIBILITY;
  3094 
  3095 * Pure: cases produced by proof methods specify options, where NONE
  3096 means to remove case bindings -- INCOMPATIBILITY in
  3097 (RAW_)METHOD_CASES.
  3098 
  3099 * Pure: the following operations retrieve axioms or theorems from a
  3100 theory node or theory hierarchy, respectively:
  3101 
  3102   Theory.axioms_of: theory -> (string * term) list
  3103   Theory.all_axioms_of: theory -> (string * term) list
  3104   PureThy.thms_of: theory -> (string * thm) list
  3105   PureThy.all_thms_of: theory -> (string * thm) list
  3106 
  3107 * Pure: print_tac now outputs the goal through the trace channel.
  3108 
  3109 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3110 Reference Toplevel.debug (default false) controls detailed printing
  3111 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3112 controls execution profiling -- set to 1 for time and 2 for space
  3113 (both increase the runtime).
  3114 
  3115 * Isar session: The initial use of ROOT.ML is now always timed,
  3116 i.e. the log will show the actual process times, in contrast to the
  3117 elapsed wall-clock time that the outer shell wrapper produces.
  3118 
  3119 * Simplifier: improved handling of bound variables (nameless
  3120 representation, avoid allocating new strings).  Simprocs that invoke
  3121 the Simplifier recursively should use Simplifier.inherit_bounds to
  3122 avoid local name clashes.  Failure to do so produces warnings
  3123 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3124 for further details.
  3125 
  3126 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3127 bindings for all theorems stored within a given theory; this may help
  3128 in porting non-Isar theories to Isar ones, while keeping ML proof
  3129 scripts for the time being.
  3130 
  3131 * ML operator HTML.with_charset specifies the charset begin used for
  3132 generated HTML files.  For example:
  3133 
  3134   HTML.with_charset "utf-8" use_thy "Hebrew";
  3135   HTML.with_charset "utf-8" use_thy "Chinese";
  3136 
  3137 
  3138 *** System ***
  3139 
  3140 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3141 isabelle, isatool etc.).
  3142 
  3143 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3144 isatool doc, isatool mkdir, display_drafts etc.).
  3145 
  3146 * isatool usedir: option -f allows specification of the ML file to be
  3147 used by Isabelle; default is ROOT.ML.
  3148 
  3149 * New isatool version outputs the version identifier of the Isabelle
  3150 distribution being used.
  3151 
  3152 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3153 (containing Boolean satisfiability problems) into Isabelle/HOL
  3154 theories.
  3155 
  3156 
  3157 
  3158 New in Isabelle2004 (April 2004)
  3159 --------------------------------
  3160 
  3161 *** General ***
  3162 
  3163 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3164   Replaces linorder.ML.
  3165 
  3166 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3167   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3168   (\<a>...\<z>), are now considered normal letters, and can therefore
  3169   be used anywhere where an ASCII letter (a...zA...Z) has until
  3170   now. COMPATIBILITY: This obviously changes the parsing of some
  3171   terms, especially where a symbol has been used as a binder, say
  3172   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3173   as an identifier.  Fix it by inserting a space around former
  3174   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3175   existing theory and ML files.
  3176 
  3177 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3178 
  3179 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3180   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3181   a normal (but invisible) letter. For multiple letter subscripts repeat
  3182   \<^isub> like this: x\<^isub>1\<^isub>2.
  3183 
  3184 * Pure: There are now sub-/superscripts that can span more than one
  3185   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3186   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3187   superscript. The new control characters are not identifier parts.
  3188 
  3189 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3190   content of "..." to the latex file instead of \isacntrl... . The "..."
  3191   may consist of any printable characters excluding the end bracket >.
  3192 
  3193 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3194   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3195   declare constants "final", which prevents their being given a definition
  3196   later.  It is useful for constants whose behaviour is fixed axiomatically
  3197   rather than definitionally, such as the meta-logic connectives.
  3198 
  3199 * Pure: 'instance' now handles general arities with general sorts
  3200   (i.e. intersections of classes),
  3201 
  3202 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3203   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3204   It can be changed to alter the colors/layout of generated pages.
  3205 
  3206 
  3207 *** Isar ***
  3208 
  3209 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3210   cut_tac, subgoal_tac and thin_tac:
  3211   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3212     locales are no longer forced to write Isar proof scripts.
  3213     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3214     emulations.
  3215   - INCOMPATIBILITY: names of variables to be instantiated may no
  3216     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3217     This is consistent with the instantiation attribute "where".
  3218 
  3219 * Attributes "where" and "of":
  3220   - Now take type variables of instantiated theorem into account when reading
  3221     the instantiation string.  This fixes a bug that caused instantiated
  3222     theorems to have too special types in some circumstances.
  3223   - "where" permits explicit instantiations of type variables.
  3224 
  3225 * Calculation commands "moreover" and "also" no longer interfere with
  3226   current facts ("this"), admitting arbitrary combinations with "then"
  3227   and derived forms.
  3228 
  3229 * Locales:
  3230   - Goal statements involving the context element "includes" no longer
  3231     generate theorems with internal delta predicates (those ending on
  3232     "_axioms") in the premise.
  3233     Resolve particular premise with <locale>.intro to obtain old form.
  3234   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3235     specification and "includes" elements in goal statement.
  3236   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3237     [intro?] and [elim?] (respectively) by default.
  3238   - Experimental command for instantiation of locales in proof contexts:
  3239         instantiate <label>[<attrs>]: <loc>
  3240     Instantiates locale <loc> and adds all its theorems to the current context
  3241     taking into account their attributes.  Label and attrs are optional
  3242     modifiers, like in theorem declarations.  If present, names of
  3243     instantiated theorems are qualified with <label>, and the attributes
  3244     <attrs> are applied after any attributes these theorems might have already.
  3245       If the locale has assumptions, a chained fact of the form
  3246     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3247     are derived.  The command does not support old-style locales declared
  3248     with "locale (open)".
  3249       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3250 
  3251 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3252   (Isar) contexts.
  3253 
  3254 
  3255 *** HOL ***
  3256 
  3257 * Proof import: new image HOL4 contains the imported library from
  3258   the HOL4 system with about 2500 theorems. It is imported by
  3259   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3260   can be used like any other Isabelle image.  See
  3261   HOL/Import/HOL/README for more information.
  3262 
  3263 * Simplifier:
  3264   - Much improved handling of linear and partial orders.
  3265     Reasoners for linear and partial orders are set up for type classes
  3266     "linorder" and "order" respectively, and are added to the default simpset
  3267     as solvers.  This means that the simplifier can build transitivity chains
  3268     to solve goals from the assumptions.
  3269   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3270     of blast or auto after simplification become unnecessary because the goal
  3271     is solved by simplification already.
  3272 
  3273 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3274     all proved in axiomatic type classes for semirings, rings and fields.
  3275 
  3276 * Numerics:
  3277   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3278     now formalized using the Ring_and_Field theory mentioned above.
  3279   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3280     than before, because now they are set up once in a generic manner.
  3281   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3282     Look for the general versions in Ring_and_Field (and Power if they concern
  3283     exponentiation).
  3284 
  3285 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3286 
  3287 * Records:
  3288   - Record types are now by default printed with their type abbreviation
  3289     instead of the list of all field types. This can be configured via
  3290     the reference "print_record_type_abbr".
  3291   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3292     (not enabled by default).
  3293   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3294     EX x. x = sel r to True (not enabled by default).
  3295   - Tactic "record_split_simp_tac" to split and simplify records added.
  3296 
  3297 * 'specification' command added, allowing for definition by
  3298   specification.  There is also an 'ax_specification' command that
  3299   introduces the new constants axiomatically.
  3300 
  3301 * arith(_tac) is now able to generate counterexamples for reals as well.
  3302 
  3303 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3304 
  3305 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3306   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3307 
  3308 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3309   matrix theory to linear programming.
  3310 
  3311 * Unions and Intersections:
  3312   The latex output syntax of UN and INT has been changed
  3313   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3314   i.e. the index formulae has become a subscript.
  3315   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3316 
  3317 * Unions and Intersections over Intervals:
  3318   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3319   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3320   like in normal math, and corresponding versions for < and for intersection.
  3321 
  3322 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3323   lexicographic dictonary ordering has been added as "lexord".
  3324 
  3325 * ML: the legacy theory structures Int and List have been removed. They had
  3326   conflicted with ML Basis Library structures having the same names.
  3327 
  3328 * 'refute' command added to search for (finite) countermodels.  Only works
  3329   for a fragment of HOL.  The installation of an external SAT solver is
  3330   highly recommended.  See "HOL/Refute.thy" for details.
  3331 
  3332 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3333   formulae under an assignment of free variables to random values.
  3334   In contrast to 'refute', it can deal with inductive datatypes,
  3335   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3336   for examples.
  3337 
  3338 
  3339 *** HOLCF ***
  3340 
  3341 * Streams now come with concatenation and are part of the HOLCF image
  3342 
  3343 
  3344 
  3345 New in Isabelle2003 (May 2003)
  3346 ------------------------------
  3347 
  3348 *** General ***
  3349 
  3350 * Provers/simplifier:
  3351 
  3352   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3353     Assumptions are now subject to complete mutual simplification,
  3354     not just from left to right. The simplifier now preserves
  3355     the order of assumptions.
  3356 
  3357     Potential INCOMPATIBILITY:
  3358 
  3359     -- simp sometimes diverges where the old version did
  3360        not, e.g. invoking simp on the goal
  3361 
  3362         [| P (f x); y = x; f x = f y |] ==> Q
  3363 
  3364        now gives rise to the infinite reduction sequence
  3365 
  3366         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3367 
  3368        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3369        kind of problem.
  3370 
  3371     -- Tactics combining classical reasoner and simplification (such as auto)
  3372        are also affected by this change, because many of them rely on
  3373        simp. They may sometimes diverge as well or yield a different numbers
  3374        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3375        in case of problems. Sometimes subsequent calls to the classical
  3376        reasoner will fail because a preceeding call to the simplifier too
  3377        eagerly simplified the goal, e.g. deleted redundant premises.
  3378 
  3379   - The simplifier trace now shows the names of the applied rewrite rules
  3380 
  3381   - You can limit the number of recursive invocations of the simplifier
  3382     during conditional rewriting (where the simplifie tries to solve the
  3383     conditions before applying the rewrite rule):
  3384     ML "simp_depth_limit := n"
  3385     where n is an integer. Thus you can force termination where previously
  3386     the simplifier would diverge.
  3387 
  3388   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3389 
  3390   - No longer aborts on failed congruence proof.  Instead, the
  3391     congruence is ignored.
  3392 
  3393 * Pure: New generic framework for extracting programs from constructive
  3394   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3395   as HOL/Extraction for some case studies.
  3396 
  3397 * Pure: The main goal of the proof state is no longer shown by default, only
  3398 the subgoals. This behaviour is controlled by a new flag.
  3399    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3400 (ML: Proof.show_main_goal).
  3401 
  3402 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3403 rules whose conclusion matches subgoal 1:
  3404       PG menu: Isabelle/Isar -> Show me -> matching rules
  3405 The rules are ordered by how closely they match the subgoal.
  3406 In particular, rules that solve a subgoal outright are displayed first
  3407 (or rather last, the way they are printed).
  3408 (ML: ProofGeneral.print_intros())
  3409 
  3410 * Pure: New flag trace_unify_fail causes unification to print
  3411 diagnostic information (PG: in trace buffer) when it fails. This is
  3412 useful for figuring out why single step proofs like rule, erule or
  3413 assumption failed.
  3414 
  3415 * Pure: Locale specifications now produce predicate definitions
  3416 according to the body of text (covering assumptions modulo local
  3417 definitions); predicate "loc_axioms" covers newly introduced text,
  3418 while "loc" is cumulative wrt. all included locale expressions; the
  3419 latter view is presented only on export into the global theory
  3420 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3421 on the old view without predicates;
  3422 
  3423 * Pure: predefined locales "var" and "struct" are useful for sharing
  3424 parameters (as in CASL, for example); just specify something like
  3425 ``var x + var y + struct M'' as import;
  3426 
  3427 * Pure: improved thms_containing: proper indexing of facts instead of
  3428 raw theorems; check validity of results wrt. current name space;
  3429 include local facts of proof configuration (also covers active
  3430 locales), cover fixed variables in index; may use "_" in term
  3431 specification; an optional limit for the number of printed facts may
  3432 be given (the default is 40);
  3433 
  3434 * Pure: disallow duplicate fact bindings within new-style theory files
  3435 (batch-mode only);
  3436 
  3437 * Provers: improved induct method: assumptions introduced by case
  3438 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3439 the goal statement); "foo" still refers to all facts collectively;
  3440 
  3441 * Provers: the function blast.overloaded has been removed: all constants
  3442 are regarded as potentially overloaded, which improves robustness in exchange
  3443 for slight decrease in efficiency;
  3444 
  3445 * Provers/linorder: New generic prover for transitivity reasoning over
  3446 linear orders.  Note: this prover is not efficient!
  3447 
  3448 * Isar: preview of problems to finish 'show' now produce an error
  3449 rather than just a warning (in interactive mode);
  3450 
  3451 
  3452 *** HOL ***
  3453 
  3454 * arith(_tac)
  3455 
  3456  - Produces a counter example if it cannot prove a goal.
  3457    Note that the counter example may be spurious if the goal is not a formula
  3458    of quantifier-free linear arithmetic.
  3459    In ProofGeneral the counter example appears in the trace buffer.
  3460 
  3461  - Knows about div k and mod k where k is a numeral of type nat or int.
  3462 
  3463  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3464    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3465    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3466 
  3467 * simp's arithmetic capabilities have been enhanced a bit: it now
  3468 takes ~= in premises into account (by performing a case split);
  3469 
  3470 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3471 are distributed over a sum of terms;
  3472 
  3473 * New tactic "trans_tac" and method "trans" instantiate
  3474 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3475 "<=", "<" and "=").
  3476 
  3477 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3478 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3479 
  3480 * 'typedef' command has new option "open" to suppress the set
  3481 definition;
  3482 
  3483 * functions Min and Max on finite sets have been introduced (theory
  3484 Finite_Set);
  3485 
  3486 * attribute [symmetric] now works for relations as well; it turns
  3487 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3488 
  3489 * induct over a !!-quantified statement (say !!x1..xn):
  3490   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3491 
  3492 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3493 %x. None. Warning: empty_def now refers to the previously hidden definition
  3494 of the empty set.
  3495 
  3496 * Algebra: formalization of classical algebra.  Intended as base for
  3497 any algebraic development in Isabelle.  Currently covers group theory
  3498 (up to Sylow's theorem) and ring theory (Universal Property of
  3499 Univariate Polynomials).  Contributions welcome;
  3500 
  3501 * GroupTheory: deleted, since its material has been moved to Algebra;
  3502 
  3503 * Complex: new directory of the complex numbers with numeric constants,
  3504 nonstandard complex numbers, and some complex analysis, standard and
  3505 nonstandard (Jacques Fleuriot);
  3506 
  3507 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3508 
  3509 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3510 Fleuriot);
  3511 
  3512 * Real/HahnBanach: updated and adapted to locales;
  3513 
  3514 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3515 Gray and Kramer);
  3516 
  3517 * UNITY: added the Meier-Sanders theory of progress sets;
  3518 
  3519 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3520 as abstract algorithms, instantiated to the JVM;
  3521 
  3522 * Bali: Java source language formalization. Type system, operational
  3523 semantics, axiomatic semantics. Supported language features:
  3524 classes, interfaces, objects,virtual methods, static methods,
  3525 static/instance fields, arrays, access modifiers, definite
  3526 assignment, exceptions.
  3527 
  3528 
  3529 *** ZF ***
  3530 
  3531 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3532 universe, etc.);
  3533 
  3534 * Main ZF: virtually all theories converted to new-style format;
  3535 
  3536 
  3537 *** ML ***
  3538 
  3539 * Pure: Tactic.prove provides sane interface for internal proofs;
  3540 omits the infamous "standard" operation, so this is more appropriate
  3541 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3542 
  3543 * Pure: improved error reporting of simprocs;
  3544 
  3545 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3546 up simprocs;
  3547 
  3548 
  3549 *** Document preparation ***
  3550 
  3551 * uses \par instead of \\ for line breaks in theory text. This may
  3552 shift some page breaks in large documents. To get the old behaviour
  3553 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3554 
  3555 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3556 other packages
  3557 
  3558 * \<euro> now needs package babel/greek instead of marvosym (which
  3559 broke \Rightarrow)
  3560 
  3561 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3562 textcomp package)
  3563 
  3564 
  3565 
  3566 New in Isabelle2002 (March 2002)
  3567 --------------------------------
  3568 
  3569 *** Document preparation ***
  3570 
  3571 * greatly simplified document preparation setup, including more
  3572 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3573 instructive isatool mkdir; users should basically be able to get
  3574 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3575 users may run a separate document processing stage manually like this:
  3576 "isatool usedir -D output HOL Test && isatool document Test/output";
  3577 
  3578 * theory dependency graph may now be incorporated into documents;
  3579 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3580 with \includegraphics of LaTeX;
  3581 
  3582 * proper spacing of consecutive markup elements, especially text
  3583 blocks after section headings;
  3584 
  3585 * support bold style (for single symbols only), input syntax is like
  3586 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3587 
  3588 * \<bullet> is now output as bold \cdot by default, which looks much
  3589 better in printed text;
  3590 
  3591 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3592 note that these symbols are currently unavailable in Proof General /
  3593 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3594 
  3595 * isatool latex no longer depends on changed TEXINPUTS, instead
  3596 isatool document copies the Isabelle style files to the target
  3597 location;
  3598 
  3599 
  3600 *** Isar ***
  3601 
  3602 * Pure/Provers: improved proof by cases and induction;
  3603   - 'case' command admits impromptu naming of parameters (such as
  3604     "case (Suc n)");
  3605   - 'induct' method divinates rule instantiation from the inductive
  3606     claim; no longer requires excessive ?P bindings for proper
  3607     instantiation of cases;
  3608   - 'induct' method properly enumerates all possibilities of set/type
  3609     rules; as a consequence facts may be also passed through *type*
  3610     rules without further ado;
  3611   - 'induct' method now derives symbolic cases from the *rulified*
  3612     rule (before it used to rulify cases stemming from the internal
  3613     atomized version); this means that the context of a non-atomic
  3614     statement becomes is included in the hypothesis, avoiding the
  3615     slightly cumbersome show "PROP ?case" form;
  3616   - 'induct' may now use elim-style induction rules without chaining
  3617     facts, using ``missing'' premises from the goal state; this allows
  3618     rules stemming from inductive sets to be applied in unstructured
  3619     scripts, while still benefitting from proper handling of non-atomic
  3620     statements; NB: major inductive premises need to be put first, all
  3621     the rest of the goal is passed through the induction;
  3622   - 'induct' proper support for mutual induction involving non-atomic
  3623     rule statements (uses the new concept of simultaneous goals, see
  3624     below);
  3625   - append all possible rule selections, but only use the first
  3626     success (no backtracking);
  3627   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3628   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3629   - added 'print_induct_rules' (covered by help item in recent Proof
  3630     General versions);
  3631   - moved induct/cases attributes to Pure, methods to Provers;
  3632   - generic method setup instantiated for FOL and HOL;
  3633 
  3634 * Pure: support multiple simultaneous goal statements, for example
  3635 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3636 meta-level mechanism, this acts as if several individual goals had
  3637 been stated separately; in particular common proof methods need to be
  3638 repeated in order to cover all claims; note that a single elimination
  3639 step is *not* sufficient to establish the two conjunctions, so this
  3640 fails:
  3641 
  3642   assume "A & B" then have A and B ..   (*".." fails*)
  3643 
  3644 better use "obtain" in situations as above; alternative refer to
  3645 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3646 
  3647 * Pure: proper integration with ``locales''; unlike the original
  3648 version by Florian Kammller, Isar locales package high-level proof
  3649 contexts rather than raw logical ones (e.g. we admit to include
  3650 attributes everywhere); operations on locales include merge and
  3651 rename; support for implicit arguments (``structures''); simultaneous
  3652 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3653 some examples;
  3654 
  3655 * Pure: the following commands have been ``localized'', supporting a
  3656 target locale specification "(in name)": 'lemma', 'theorem',
  3657 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3658 stored both within the locale and at the theory level (exported and
  3659 qualified by the locale name);
  3660 
  3661 * Pure: theory goals may now be specified in ``long'' form, with
  3662 ad-hoc contexts consisting of arbitrary locale elements. for example
  3663 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3664 definitions may be given, too); the result is a meta-level rule with
  3665 the context elements being discharged in the obvious way;
  3666 
  3667 * Pure: new proof command 'using' allows to augment currently used
  3668 facts after a goal statement ('using' is syntactically analogous to
  3669 'apply', but acts on the goal's facts only); this allows chained facts
  3670 to be separated into parts given before and after a claim, as in
  3671 ``from a and b have C using d and e <proof>'';
  3672 
  3673 * Pure: renamed "antecedent" case to "rule_context";
  3674 
  3675 * Pure: new 'judgment' command records explicit information about the
  3676 object-logic embedding (used by several tools internally); no longer
  3677 use hard-wired "Trueprop";
  3678 
  3679 * Pure: added 'corollary' command;
  3680 
  3681 * Pure: fixed 'token_translation' command;
  3682 
  3683 * Pure: removed obsolete 'exported' attribute;
  3684 
  3685 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3686 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3687 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3688 
  3689 * Pure: method 'atomize' presents local goal premises as object-level
  3690 statements (atomic meta-level propositions); setup controlled via
  3691 rewrite rules declarations of 'atomize' attribute; example
  3692 application: 'induct' method with proper rule statements in improper
  3693 proof *scripts*;
  3694 
  3695 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3696 now consider the syntactic context of assumptions, giving a better
  3697 chance to get type-inference of the arguments right (this is
  3698 especially important for locales);
  3699 
  3700 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3701 mode;
  3702 
  3703 * Pure/obtain: the formal conclusion "thesis", being marked as
  3704 ``internal'', may no longer be reference directly in the text;
  3705 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3706 situations;
  3707 
  3708 * Pure: generic 'sym' attribute which declares a rule both as pure
  3709 'elim?' and for the 'symmetric' operation;
  3710 
  3711 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3712 text; the fixed correlation with particular command syntax has been
  3713 discontinued;
  3714 
  3715 * Pure: new method 'rules' is particularly well-suited for proof
  3716 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3717 but often produces more compact proof terms with less detours;
  3718 
  3719 * Pure/Provers/classical: simplified integration with pure rule
  3720 attributes and methods; the classical "intro?/elim?/dest?"
  3721 declarations coincide with the pure ones; the "rule" method no longer
  3722 includes classically swapped intros; "intro" and "elim" methods no
  3723 longer pick rules from the context; also got rid of ML declarations
  3724 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3725 INCOMPATIBILITY;
  3726 
  3727 * Provers/classical: attribute 'swapped' produces classical inversions
  3728 of introduction rules;
  3729 
  3730 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3731 rules instead of full simplifier context; 'iff' attribute handles
  3732 conditional rules;
  3733 
  3734 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3735 
  3736 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3737 "(permissive)" option to recover old behavior;
  3738 
  3739 * HOL: 'inductive' no longer features separate (collective) attributes
  3740 for 'intros' (was found too confusing);
  3741 
  3742 * HOL: properly declared induction rules less_induct and
  3743 wf_induct_rule;
  3744 
  3745 
  3746 *** HOL ***
  3747 
  3748 * HOL: moved over to sane numeral syntax; the new policy is as
  3749 follows:
  3750 
  3751   - 0 and 1 are polymorphic constants, which are defined on any
  3752   numeric type (nat, int, real etc.);
  3753 
  3754   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3755   binary representation internally;
  3756 
  3757   - type nat has special constructor Suc, and generally prefers Suc 0
  3758   over 1::nat and Suc (Suc 0) over 2::nat;
  3759 
  3760 This change may cause significant problems of INCOMPATIBILITY; here
  3761 are some hints on converting existing sources:
  3762 
  3763   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3764   entities, so expressions involving "-" (unary or binary minus) need
  3765   to be spaced properly;
  3766 
  3767   - existing occurrences of "1" may need to be constraint "1::nat" or
  3768   even replaced by Suc 0; similar for old "2";
  3769 
  3770   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3771 
  3772   - remove all special provisions on numerals in proofs;
  3773 
  3774 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3775 representation (depends on bin_arith_simps in the default context);
  3776 
  3777 * HOL: symbolic syntax for x^2 (numeral 2);
  3778 
  3779 * HOL: the class of all HOL types is now called "type" rather than
  3780 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3781 in axclass/classes, instance/arities, and (usually rare) occurrences
  3782 in typings (of consts etc.); internally the class is called
  3783 "HOL.type", ML programs should refer to HOLogic.typeS;
  3784 
  3785 * HOL/record package improvements:
  3786   - new derived operations "fields" to build a partial record section,
  3787     "extend" to promote a fixed record to a record scheme, and
  3788     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3789     declared as simp by default;
  3790   - shared operations ("more", "fields", etc.) now need to be always
  3791     qualified) --- potential INCOMPATIBILITY;
  3792   - removed "make_scheme" operations (use "make" with "extend") --
  3793     INCOMPATIBILITY;
  3794   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3795   - provides cases/induct rules for use with corresponding Isar
  3796     methods (for concrete records, record schemes, concrete more
  3797     parts, and schematic more parts -- in that order);
  3798   - internal definitions directly based on a light-weight abstract
  3799     theory of product types over typedef rather than datatype;
  3800 
  3801 * HOL: generic code generator for generating executable ML code from
  3802 specifications; specific support for HOL constructs such as inductive
  3803 datatypes and sets, as well as recursive functions; can be invoked
  3804 via 'generate_code' theory section;
  3805 
  3806 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3807 
  3808 * HOL: consolidated and renamed several theories.  In particular:
  3809         Ord.thy has been absorbed into HOL.thy
  3810         String.thy has been absorbed into List.thy
  3811 
  3812 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3813 (beware of argument permutation!);
  3814 
  3815 * HOL: linorder_less_split superseded by linorder_cases;
  3816 
  3817 * HOL/List: "nodups" renamed to "distinct";
  3818 
  3819 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3820 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3821   - Ex_def has changed, now need to use some_eq_ex
  3822 
  3823 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3824 in this (rare) case use:
  3825 
  3826   delSWrapper "split_all_tac"
  3827   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3828 
  3829 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3830 MAY FAIL;
  3831 
  3832 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3833 Isabelle's type classes, ^ on functions and relations has too general
  3834 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3835 necessary to attach explicit type constraints;
  3836 
  3837 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3838 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3839 renamed accordingly (eg "compI" -> "rel_compI").
  3840 
  3841 * HOL: syntax translations now work properly with numerals and records
  3842 expressions;
  3843 
  3844 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3845 of "lam" -- INCOMPATIBILITY;
  3846 
  3847 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3848 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3849 renamed "Product_Type.unit";
  3850 
  3851 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3852 
  3853 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3854 the "cases" method);
  3855 
  3856 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3857 Florian Kammller);
  3858 
  3859 * HOL/IMP: updated and converted to new-style theory format; several
  3860 parts turned into readable document, with proper Isar proof texts and
  3861 some explanations (by Gerwin Klein);
  3862 
  3863 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3864 
  3865 * HOL-Hyperreal is now a logic image;
  3866 
  3867 
  3868 *** HOLCF ***
  3869 
  3870 * Isar: consts/constdefs supports mixfix syntax for continuous
  3871 operations;
  3872 
  3873 * Isar: domain package adapted to new-style theory format, e.g. see
  3874 HOLCF/ex/Dnat.thy;
  3875 
  3876 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3877 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3878 lift.induct_tac, always use UU instead of Undef;
  3879 
  3880 * HOLCF/IMP: updated and converted to new-style theory;
  3881 
  3882 
  3883 *** ZF ***
  3884 
  3885 * Isar: proper integration of logic-specific tools and packages,
  3886 including theory commands '(co)inductive', '(co)datatype',
  3887 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3888 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3889 
  3890 * theory Main no longer includes AC; for the Axiom of Choice, base
  3891 your theory on Main_ZFC;
  3892 
  3893 * the integer library now covers quotients and remainders, with many
  3894 laws relating division to addition, multiplication, etc.;
  3895 
  3896 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3897 typeless version of the formalism;
  3898 
  3899 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3900 format;
  3901 
  3902 * ZF/Induct: new directory for examples of inductive definitions,
  3903 including theory Multiset for multiset orderings; converted to
  3904 new-style theory format;
  3905 
  3906 * ZF: many new theorems about lists, ordinals, etc.;
  3907 
  3908 
  3909 *** General ***
  3910 
  3911 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3912 variable proof controls level of detail: 0 = no proofs (only oracle
  3913 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3914 also ref manual for further ML interfaces;
  3915 
  3916 * Pure/axclass: removed obsolete ML interface
  3917 goal_subclass/goal_arity;
  3918 
  3919 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3920 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3921 separate tokens, so expressions involving minus need to be spaced
  3922 properly;
  3923 
  3924 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3925 rather than "infixl" or "infixr";
  3926 
  3927 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3928 sort constraint specifications in type inference; e.g. "x::_::foo"
  3929 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3930 type variable);
  3931 
  3932 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3933 control output of nested => (types); the default behavior is
  3934 "type_brackets";
  3935 
  3936 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3937 tokens into AST constants;
  3938 
  3939 * Pure/syntax: prefer later declarations of translations and print
  3940 translation functions; potential INCOMPATIBILITY: need to reverse
  3941 multiple declarations for same syntax element constant;
  3942 
  3943 * Pure/show_hyps reset by default (in accordance to existing Isar
  3944 practice);
  3945 
  3946 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3947 addSafter;
  3948 
  3949 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3950 as well;
  3951 
  3952 * system: tested support for MacOS X; should be able to get Isabelle +
  3953 Proof General to work in a plain Terminal after installing Poly/ML
  3954 (e.g. from the Isabelle distribution area) and GNU bash alone
  3955 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3956 support requires further installations, e.g. from
  3957 http://fink.sourceforge.net/);
  3958 
  3959 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3960 
  3961 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3962 of 40 MB), cf. ML_OPTIONS;
  3963 
  3964 * system: Proof General keywords specification is now part of the
  3965 Isabelle distribution (see etc/isar-keywords.el);
  3966 
  3967 * system: support for persistent Proof General sessions (refrain from
  3968 outdating all loaded theories on startup); user may create writable
  3969 logic images like this: ``isabelle -q HOL Test'';
  3970 
  3971 * system: smart selection of Isabelle process versus Isabelle
  3972 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3973 run both "isabelle" and "Isabelle" even if file names are badly
  3974 damaged (executable inspects the case of the first letter of its own
  3975 name); added separate "isabelle-process" and "isabelle-interface";
  3976 
  3977 * system: refrain from any attempt at filtering input streams; no
  3978 longer support ``8bit'' encoding of old isabelle font, instead proper
  3979 iso-latin characters may now be used; the related isatools
  3980 "symbolinput" and "nonascii" have disappeared as well;
  3981 
  3982 * system: removed old "xterm" interface (the print modes "xterm" and
  3983 "xterm_color" are still available for direct use in a suitable
  3984 terminal);
  3985 
  3986 
  3987 
  3988 New in Isabelle99-2 (February 2001)
  3989 -----------------------------------
  3990 
  3991 *** Overview of INCOMPATIBILITIES ***
  3992 
  3993 * HOL: please note that theories in the Library and elsewhere often use the
  3994 new-style (Isar) format; to refer to their theorems in an ML script you must
  3995 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3996 
  3997 * HOL: inductive package no longer splits induction rule aggressively,
  3998 but only as far as specified by the introductions given; the old
  3999 format may be recovered via ML function complete_split_rule or attribute
  4000 'split_rule (complete)';
  4001 
  4002 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4003 gfp_Tarski to gfp_unfold;
  4004 
  4005 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4006 
  4007 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4008 relation); infix "^^" has been renamed "``"; infix "``" has been
  4009 renamed "`"; "univalent" has been renamed "single_valued";
  4010 
  4011 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4012 operation;
  4013 
  4014 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4015 
  4016 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4017 
  4018 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4019 consequence, it is no longer monotonic wrt. the local goal context
  4020 (which is now passed through the inductive cases);
  4021 
  4022 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4023 \<gg> to \<ggreater>;
  4024 
  4025 
  4026 *** Document preparation ***
  4027 
  4028 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4029 available: are "it" for near math-mode best-style output, "sl" for
  4030 slanted text style, and "tt" for plain type-writer; if no
  4031 \isabellestyle command is given, output is according to slanted
  4032 type-writer);
  4033 
  4034 * support sub/super scripts (for single symbols only), input syntax is
  4035 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4036 
  4037 * some more standard symbols; see Appendix A of the system manual for
  4038 the complete list of symbols defined in isabellesym.sty;
  4039 
  4040 * improved isabelle style files; more abstract symbol implementation
  4041 (should now use \isamath{...} and \isatext{...} in custom symbol
  4042 definitions);
  4043 
  4044 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4045 state; Note that presentation of goal states does not conform to
  4046 actual human-readable proof documents.  Please do not include goal
  4047 states into document output unless you really know what you are doing!
  4048 
  4049 * proper indentation of antiquoted output with proportional LaTeX
  4050 fonts;
  4051 
  4052 * no_document ML operator temporarily disables LaTeX document
  4053 generation;
  4054 
  4055 * isatool unsymbolize tunes sources for plain ASCII communication;
  4056 
  4057 
  4058 *** Isar ***
  4059 
  4060 * Pure: Isar now suffers initial goal statements to contain unbound
  4061 schematic variables (this does not conform to actual readable proof
  4062 documents, due to unpredictable outcome and non-compositional proof
  4063 checking); users who know what they are doing may use schematic goals
  4064 for Prolog-style synthesis of proven results;
  4065 
  4066 * Pure: assumption method (an implicit finishing) now handles actual
  4067 rules as well;
  4068 
  4069 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4070 initial goal, declare "that" only as Pure intro (only for single
  4071 steps); the "that" rule assumption may now be involved in implicit
  4072 finishing, thus ".." becomes a feasible for trivial obtains;
  4073 
  4074 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4075 instance proofs may be performed by "..";
  4076 
  4077 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4078 statements as well;
  4079 
  4080 * Pure: more robust selection of calculational rules;
  4081 
  4082 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4083 rule (as well as the assumption rule);
  4084 
  4085 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4086 lemmas, using the graph browser tool;
  4087 
  4088 * Pure: predict failure of "show" in interactive mode;
  4089 
  4090 * Pure: 'thms_containing' now takes actual terms as arguments;
  4091 
  4092 * HOL: improved method 'induct' --- now handles non-atomic goals
  4093 (potential INCOMPATIBILITY); tuned error handling;
  4094 
  4095 * HOL: cases and induct rules now provide explicit hints about the
  4096 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4097 any remaining facts are inserted into the goal verbatim;
  4098 
  4099 * HOL: local contexts (aka cases) may now contain term bindings as
  4100 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4101 the result to be shown in each case;
  4102 
  4103 * HOL: added 'recdef_tc' command;
  4104 
  4105 * isatool convert assists in eliminating legacy ML scripts;
  4106 
  4107 
  4108 *** HOL ***
  4109 
  4110 * HOL/Library: a collection of generic theories to be used together
  4111 with main HOL; the theory loader path already includes this directory
  4112 by default; the following existing theories have been moved here:
  4113 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4114 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4115 
  4116 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4117 modelling and verification task performed in Isabelle/HOL +
  4118 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4119 
  4120 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4121 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4122 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4123 'domain', this makes the theory consistent with mathematical
  4124 literature;
  4125 
  4126 * HOL basics: added overloaded operations "inverse" and "divide"
  4127 (infix "/"), syntax for generic "abs" operation, generic summation
  4128 operator \<Sum>;
  4129 
  4130 * HOL/typedef: simplified package, provide more useful rules (see also
  4131 HOL/subset.thy);
  4132 
  4133 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4134 now expressed as a proper nested rule (old-style tactic scripts may
  4135 require atomize_strip_tac to cope with non-atomic premises);
  4136 
  4137 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4138 to "split_conv" (old name still available for compatibility);
  4139 
  4140 * HOL: improved concrete syntax for strings (e.g. allows translation
  4141 rules with string literals);
  4142 
  4143 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4144  and Fleuriot's mechanization of analysis, including the transcendental
  4145  functions for the reals;
  4146 
  4147 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4148 
  4149 
  4150 *** CTT ***
  4151 
  4152 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4153 "lam" is displayed as TWO lambda-symbols
  4154 
  4155 * CTT: theory Main now available, containing everything (that is, Bool
  4156 and Arith);
  4157 
  4158 
  4159 *** General ***
  4160 
  4161 * Pure: the Simplifier has been implemented properly as a derived rule
  4162 outside of the actual kernel (at last!); the overall performance
  4163 penalty in practical applications is about 50%, while reliability of
  4164 the Isabelle inference kernel has been greatly improved;
  4165 
  4166 * print modes "brackets" and "no_brackets" control output of nested =>
  4167 (types) and ==> (props); the default behaviour is "brackets";
  4168 
  4169 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4170 as assumptions as well;
  4171 
  4172 * system: support Poly/ML 4.0;
  4173 
  4174 * system: isatool install handles KDE version 1 or 2;
  4175 
  4176 
  4177 
  4178 New in Isabelle99-1 (October 2000)
  4179 ----------------------------------
  4180 
  4181 *** Overview of INCOMPATIBILITIES ***
  4182 
  4183 * HOL: simplification of natural numbers is much changed; to partly
  4184 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4185 issue the following ML commands:
  4186 
  4187   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4188   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4189 
  4190 * HOL: simplification no longer dives into case-expressions; this is
  4191 controlled by "t.weak_case_cong" for each datatype t;
  4192 
  4193 * HOL: nat_less_induct renamed to less_induct;
  4194 
  4195 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4196 fixsome to patch .thy and .ML sources automatically;
  4197 
  4198   select_equality  -> some_equality
  4199   select_eq_Ex     -> some_eq_ex
  4200   selectI2EX       -> someI2_ex
  4201   selectI2         -> someI2
  4202   selectI          -> someI
  4203   select1_equality -> some1_equality
  4204   Eps_sym_eq       -> some_sym_eq_trivial
  4205   Eps_eq           -> some_eq_trivial
  4206 
  4207 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4208 
  4209 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4210 instead);
  4211 
  4212 * HOL: the recursion equations generated by 'recdef' are now called
  4213 f.simps instead of f.rules;
  4214 
  4215 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4216 
  4217 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4218 sometimes be needed;
  4219 
  4220 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4221 
  4222 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4223 
  4224 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4225 product is now "<*>" instead of "Times"; the lexicographic product is
  4226 now "<*lex*>" instead of "**";
  4227 
  4228 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4229 of main HOL, but was unused); better use HOL's datatype package;
  4230 
  4231 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4232 the old syntax may be recovered as follows:
  4233 
  4234   syntax (symbols)
  4235     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4236       (infixl "\\<oplus>" 100)
  4237 
  4238 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4239 
  4240 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4241 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4242 internally;
  4243 
  4244 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4245 changed from A/r to A//r;
  4246 
  4247 * ZF: new treatment of arithmetic (nat & int) may break some old
  4248 proofs;
  4249 
  4250 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4251 rulify -> rule_format, elimify -> elim_format, ...);
  4252 
  4253 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4254 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4255 should have to change intro!! to intro? only); replaced "delrule" by
  4256 "rule del";
  4257 
  4258 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4259 
  4260 * Provers: strengthened force_tac by using new first_best_tac;
  4261 
  4262 * LaTeX document preparation: several changes of isabelle.sty (see
  4263 lib/texinputs);
  4264 
  4265 
  4266 *** Document preparation ***
  4267 
  4268 * formal comments (text blocks etc.) in new-style theories may now
  4269 contain antiquotations of thm/prop/term/typ/text to be presented
  4270 according to latex print mode; concrete syntax is like this:
  4271 @{term[show_types] "f(x) = a + x"};
  4272 
  4273 * isatool mkdir provides easy setup of Isabelle session directories,
  4274 including proper document sources;
  4275 
  4276 * generated LaTeX sources are now deleted after successful run
  4277 (isatool document -c); may retain a copy somewhere else via -D option
  4278 of isatool usedir;
  4279 
  4280 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4281 style files, achieving self-contained LaTeX sources and simplifying
  4282 LaTeX debugging;
  4283 
  4284 * old-style theories now produce (crude) LaTeX output as well;
  4285 
  4286 * browser info session directories are now self-contained (may be put
  4287 on WWW server seperately); improved graphs of nested sessions; removed
  4288 graph for 'all sessions';
  4289 
  4290 * several improvements in isabelle style files; \isabellestyle{it}
  4291 produces fake math mode output; \isamarkupheader is now \section by
  4292 default; see lib/texinputs/isabelle.sty etc.;
  4293 
  4294 
  4295 *** Isar ***
  4296 
  4297 * Isar/Pure: local results and corresponding term bindings are now
  4298 subject to Hindley-Milner polymorphism (similar to ML); this
  4299 accommodates incremental type-inference very nicely;
  4300 
  4301 * Isar/Pure: new derived language element 'obtain' supports
  4302 generalized existence reasoning;
  4303 
  4304 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4305 support accumulation of results, without applying any rules yet;
  4306 useful to collect intermediate results without explicit name
  4307 references, and for use with transitivity rules with more than 2
  4308 premises;
  4309 
  4310 * Isar/Pure: scalable support for case-analysis type proofs: new
  4311 'case' language element refers to local contexts symbolically, as
  4312 produced by certain proof methods; internally, case names are attached
  4313 to theorems as "tags";
  4314 
  4315 * Isar/Pure: theory command 'hide' removes declarations from
  4316 class/type/const name spaces;
  4317 
  4318 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4319 indicate potential overloading;
  4320 
  4321 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4322 
  4323 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4324 "{a,b,c}" instead of {a,b,c};
  4325 
  4326 * Isar/Pure now provides its own version of intro/elim/dest
  4327 attributes; useful for building new logics, but beware of confusion
  4328 with the version in Provers/classical;
  4329 
  4330 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4331 case name 'antecedent';
  4332 
  4333 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4334 to the current context is now done automatically);
  4335 
  4336 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4337 for definining proof methods in ML;
  4338 
  4339 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4340 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4341 most cases, one should have to change intro!! to intro? only);
  4342 replaced "delrule" by "rule del";
  4343 
  4344 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4345 'symmetric' attribute (the latter supercedes [RS sym]);
  4346 
  4347 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4348 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4349 well (including splits);
  4350 
  4351 * Isar/Provers: Simplifier and Classical methods now support all kind
  4352 of modifiers used in the past, including 'cong', 'iff', etc.
  4353 
  4354 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4355 of Simplifier and Classical reasoner);
  4356 
  4357 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4358 now support named cases; major packages (inductive, datatype, primrec,
  4359 recdef) support case names and properly name parameters;
  4360 
  4361 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4362 monotonicity conditions are extracted to be proven at end of
  4363 calculations;
  4364 
  4365 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4366 method anyway;
  4367 
  4368 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4369 split_if split_if_asm; datatype package provides theorems foo.splits =
  4370 foo.split foo.split_asm for each datatype;
  4371 
  4372 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4373 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4374 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4375 use "(cases (simplified))" method in proper proof texts);
  4376 
  4377 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4378 
  4379 * Isar: names of theorems etc. may be natural numbers as well;
  4380 
  4381 * Isar: 'pr' command: optional arguments for goals_limit and
  4382 ProofContext.prems_limit; no longer prints theory contexts, but only
  4383 proof states;
  4384 
  4385 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4386 additional print modes to be specified; e.g. "pr(latex)" will print
  4387 proof state according to the Isabelle LaTeX style;
  4388 
  4389 * Isar: improved support for emulating tactic scripts, including proof
  4390 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4391 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4392 (for HOL datatypes);
  4393 
  4394 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4395 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4396 'proof method scripts' have to be in depth-first order;
  4397 
  4398 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4399 
  4400 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4401 should instead use individual commands for printing items
  4402 (print_commands, print_methods etc.);
  4403 
  4404 * Isar: added 'nothing' --- the empty list of theorems;
  4405 
  4406 
  4407 *** HOL ***
  4408 
  4409 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4410 corresponding virtual machine and a specification of its bytecode
  4411 verifier and a lightweight bytecode verifier, including proofs of
  4412 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4413 Cornelia Pusch (see also the homepage of project Bali at
  4414 http://isabelle.in.tum.de/Bali/);
  4415 
  4416 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4417 Clemens Ballarin;
  4418 
  4419 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4420 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4421 Rasmussen;
  4422 
  4423 * HOL/Lattice: fundamental concepts of lattice theory and order
  4424 structures, including duals, properties of bounds versus algebraic
  4425 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4426 Theorem for complete lattices etc.; may also serve as a demonstration
  4427 for abstract algebraic reasoning using axiomatic type classes, and
  4428 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4429 
  4430 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4431 von Oheimb;
  4432 
  4433 * HOL/IMPP: extension of IMP with local variables and mutually
  4434 recursive procedures, by David von Oheimb;
  4435 
  4436 * HOL/Lambda: converted into new-style theory and document;
  4437 
  4438 * HOL/ex/Multiquote: example of multiple nested quotations and
  4439 anti-quotations -- basically a generalized version of de-Bruijn
  4440 representation; very useful in avoiding lifting of operations;
  4441 
  4442 * HOL/record: added general record equality rule to simpset; fixed
  4443 select-update simplification procedure to handle extended records as
  4444 well; admit "r" as field name;
  4445 
  4446 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4447 other numeric types and also as the identity of groups, rings, etc.;
  4448 
  4449 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4450 Types nat and int belong to this axclass;
  4451 
  4452 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4453    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4454    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4455   two terms #m*u and #n*u are replaced by #(m+n)*u
  4456     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4457   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4458     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4459 
  4460 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4461 powerful prover for predicate logic but knows nothing of clasets; see
  4462 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4463 
  4464 * HOL: new version of "case_tac" subsumes both boolean case split and
  4465 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4466 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4467 
  4468 * HOL: simplification no longer dives into case-expressions: only the
  4469 selector expression is simplified, but not the remaining arms; to
  4470 enable full simplification of case-expressions for datatype t, you may
  4471 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4472 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4473 
  4474 * HOL/recdef: the recursion equations generated by 'recdef' for
  4475 function 'f' are now called f.simps instead of f.rules; if all
  4476 termination conditions are proved automatically, these simplification
  4477 rules are added to the simpset, as in primrec; rules may be named
  4478 individually as well, resulting in a separate list of theorems for
  4479 each equation;
  4480 
  4481 * HOL/While is a new theory that provides a while-combinator. It
  4482 permits the definition of tail-recursive functions without the
  4483 provision of a termination measure. The latter is necessary once the
  4484 invariant proof rule for while is applied.
  4485 
  4486 * HOL: new (overloaded) notation for the set of elements below/above
  4487 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4488 
  4489 * HOL: theorems impI, allI, ballI bound as "strip";
  4490 
  4491 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4492 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4493 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4494 
  4495 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4496 
  4497 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4498 main HOL, but was unused);
  4499 
  4500 * HOL: fewer consts declared as global (e.g. have to refer to
  4501 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4502 
  4503 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4504 in case of overlap with user translations (e.g. judgements over
  4505 tuples); (note that the underlying logical represenation is still
  4506 bogus);
  4507 
  4508 
  4509 *** ZF ***
  4510 
  4511 * ZF: simplification automatically cancels common terms in arithmetic
  4512 expressions over nat and int;
  4513 
  4514 * ZF: new treatment of nat to minimize type-checking: all operators
  4515 coerce their operands to a natural number using the function natify,
  4516 making the algebraic laws unconditional;
  4517 
  4518 * ZF: as above, for int: operators coerce their operands to an integer
  4519 using the function intify;
  4520 
  4521 * ZF: the integer library now contains many of the usual laws for the
  4522 orderings, including $<=, and monotonicity laws for $+ and $*;
  4523 
  4524 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4525 simplification;
  4526 
  4527 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4528 to the simplifier and classical reasoner simultaneously;
  4529 
  4530 
  4531 *** General ***
  4532 
  4533 * Provers: blast_tac now handles actual object-logic rules as
  4534 assumptions; note that auto_tac uses blast_tac internally as well;
  4535 
  4536 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4537 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4538 
  4539 * Provers: delrules now handles destruct rules as well (no longer need
  4540 explicit make_elim);
  4541 
  4542 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4543   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4544 use instead the strong form,
  4545   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4546 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4547 from destruct-rules;
  4548 
  4549 * Provers: Simplifier.easy_setup provides a fast path to basic
  4550 Simplifier setup for new object-logics;
  4551 
  4552 * Pure: AST translation rules no longer require constant head on LHS;
  4553 
  4554 * Pure: improved name spaces: ambiguous output is qualified; support
  4555 for hiding of names;
  4556 
  4557 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4558 XSYMBOL_HOME; no longer need to do manual configuration in most
  4559 situations;
  4560 
  4561 * system: compression of ML heaps images may now be controlled via -c
  4562 option of isabelle and isatool usedir (currently only observed by
  4563 Poly/ML);
  4564 
  4565 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4566 useful for remote X11);
  4567 
  4568 * system: provide TAGS file for Isabelle sources;
  4569 
  4570 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4571 order;
  4572 
  4573 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4574 timing flag supersedes proof_timing and Toplevel.trace;
  4575 
  4576 * ML: new combinators |>> and |>>> for incremental transformations
  4577 with secondary results (e.g. certain theory extensions):
  4578 
  4579 * ML: PureThy.add_defs gets additional argument to indicate potential
  4580 overloading (usually false);
  4581 
  4582 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4583 results;
  4584 
  4585 
  4586 
  4587 New in Isabelle99 (October 1999)
  4588 --------------------------------
  4589 
  4590 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4591 
  4592 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4593 are no longer simplified.  (This allows the simplifier to unfold recursive
  4594 functional programs.)  To restore the old behaviour, declare
  4595 
  4596     Delcongs [if_weak_cong];
  4597 
  4598 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4599 complement;
  4600 
  4601 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4602 
  4603 * HOL/datatype: mutual_induct_tac no longer exists --
  4604   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4605 
  4606 * HOL/typedef: fixed type inference for representing set; type
  4607 arguments now have to occur explicitly on the rhs as type constraints;
  4608 
  4609 * ZF: The con_defs part of an inductive definition may no longer refer
  4610 to constants declared in the same theory;
  4611 
  4612 * HOL, ZF: the function mk_cases, generated by the inductive
  4613 definition package, has lost an argument.  To simplify its result, it
  4614 uses the default simpset instead of a supplied list of theorems.
  4615 
  4616 * HOL/List: the constructors of type list are now Nil and Cons;
  4617 
  4618 * Simplifier: the type of the infix ML functions
  4619         setSSolver addSSolver setSolver addSolver
  4620 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4621 for packaging solvers. A solver is created via
  4622         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4623 where the string argument is only a comment.
  4624 
  4625 
  4626 *** Proof tools ***
  4627 
  4628 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4629 decision procedure for linear arithmetic. Currently it is used for
  4630 types `nat', `int', and `real' in HOL (see below); it can, should and
  4631 will be instantiated for other types and logics as well.
  4632 
  4633 * The simplifier now accepts rewrite rules with flexible heads, eg
  4634      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4635   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4636   matching.
  4637 
  4638 
  4639 *** General ***
  4640 
  4641 * New Isabelle/Isar subsystem provides an alternative to traditional
  4642 tactical theorem proving; together with the ProofGeneral/isar user
  4643 interface it offers an interactive environment for developing human
  4644 readable proof documents (Isar == Intelligible semi-automated
  4645 reasoning); for further information see isatool doc isar-ref,
  4646 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4647 
  4648 * improved and simplified presentation of theories: better HTML markup
  4649 (including colors), graph views in several sizes; isatool usedir now
  4650 provides a proper interface for user theories (via -P option); actual
  4651 document preparation based on (PDF)LaTeX is available as well (for
  4652 new-style theories only); see isatool doc system for more information;
  4653 
  4654 * native support for Proof General, both for classic Isabelle and
  4655 Isabelle/Isar;
  4656 
  4657 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4658 using the graph browser tool;
  4659 
  4660 * Isabelle manuals now also available as PDF;
  4661 
  4662 * theory loader rewritten from scratch (may not be fully
  4663 bug-compatible); old loadpath variable has been replaced by show_path,
  4664 add_path, del_path, reset_path functions; new operations such as
  4665 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4666 isatool doc ref);
  4667 
  4668 * improved isatool install: option -k creates KDE application icon,
  4669 option -p DIR installs standalone binaries;
  4670 
  4671 * added ML_PLATFORM setting (useful for cross-platform installations);
  4672 more robust handling of platform specific ML images for SML/NJ;
  4673 
  4674 * the settings environment is now statically scoped, i.e. it is never
  4675 created again in sub-processes invoked from isabelle, isatool, or
  4676 Isabelle;
  4677 
  4678 * path element specification '~~' refers to '$ISABELLE_HOME';
  4679 
  4680 * in locales, the "assumes" and "defines" parts may be omitted if
  4681 empty;
  4682 
  4683 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4684 long arrows);
  4685 
  4686 * new print_mode "HTML";
  4687 
  4688 * new flag show_tags controls display of tags of theorems (which are
  4689 basically just comments that may be attached by some tools);
  4690 
  4691 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4692 mode and goal output format:
  4693 
  4694 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4695 244c244
  4696 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4697 ---
  4698 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4699 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4700 181c181
  4701 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4702 ---
  4703 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4704 
  4705 * function bind_thms stores lists of theorems (cf. bind_thm);
  4706 
  4707 * new shorthand tactics ftac, eatac, datac, fatac;
  4708 
  4709 * qed (and friends) now accept "" as result name; in that case the
  4710 theorem is not stored, but proper checks and presentation of the
  4711 result still apply;
  4712 
  4713 * theorem database now also indexes constants "Trueprop", "all",
  4714 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4715 
  4716 
  4717 *** HOL ***
  4718 
  4719 ** HOL arithmetic **
  4720 
  4721 * There are now decision procedures for linear arithmetic over nat and
  4722 int:
  4723 
  4724 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4725 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4726 are treated as atomic; subformulae not involving type `nat' or `int'
  4727 are ignored; quantified subformulae are ignored unless they are
  4728 positive universal or negative existential. The tactic has to be
  4729 invoked by hand and can be a little bit slow. In particular, the
  4730 running time is exponential in the number of occurrences of `min' and
  4731 `max', and `-' on `nat'.
  4732 
  4733 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4734 (negated) (in)equalities among the premises and the conclusion into
  4735 account (i.e. no compound formulae) and does not know about `min' and
  4736 `max', and `-' on `nat'. It is fast and is used automatically by the
  4737 simplifier.
  4738 
  4739 NB: At the moment, these decision procedures do not cope with mixed
  4740 nat/int formulae where the two parts interact, such as `m < n ==>
  4741 int(m) < int(n)'.
  4742 
  4743 * HOL/Numeral provides a generic theory of numerals (encoded
  4744 efficiently as bit strings); setup for types nat/int/real is in place;
  4745 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4746 int, existing theories and proof scripts may require a few additional
  4747 type constraints;
  4748 
  4749 * integer division and remainder can now be performed on constant
  4750 arguments;
  4751 
  4752 * many properties of integer multiplication, division and remainder
  4753 are now available;
  4754 
  4755 * An interface to the Stanford Validity Checker (SVC) is available through the
  4756 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4757 are proved automatically.  SVC must be installed separately, and its results
  4758 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4759 invocation of the underlying oracle).  For SVC see
  4760   http://verify.stanford.edu/SVC
  4761 
  4762 * IsaMakefile: the HOL-Real target now builds an actual image;
  4763 
  4764 
  4765 ** HOL misc **
  4766 
  4767 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4768 (in Isabelle/Isar) -- by Gertrud Bauer;
  4769 
  4770 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4771 analysis for assembly languages with subtypes;
  4772 
  4773 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4774 -- avoids syntactic ambiguities and treats state, transition, and
  4775 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4776 changed syntax and (many) tactics;
  4777 
  4778 * HOL/inductive: Now also handles more general introduction rules such
  4779   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4780   theorems are now maintained within the theory (maintained via the
  4781   "mono" attribute);
  4782 
  4783 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4784   (using function types) such as
  4785 
  4786   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4787 
  4788 * HOL/record: record_simproc (part of the default simpset) takes care
  4789 of selectors applied to updated records; record_split_tac is no longer
  4790 part of the default claset; update_defs may now be removed from the
  4791 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4792 
  4793   claset_ref () := claset() addSWrapper record_split_wrapper;
  4794   Delsimprocs [record_simproc]
  4795 
  4796 * HOL/typedef: fixed type inference for representing set; type
  4797 arguments now have to occur explicitly on the rhs as type constraints;
  4798 
  4799 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4800 names rather than an ML expression;
  4801 
  4802 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4803 supplied later.  Program schemes can be defined, such as
  4804     "While B C s = (if B s then While B C (C s) else s)"
  4805 where the well-founded relation can be chosen after B and C have been given.
  4806 
  4807 * HOL/List: the constructors of type list are now Nil and Cons;
  4808 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4809 course, ML tools referring to List.list.op # etc. have to be adapted;
  4810 
  4811 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4812 disabled by default; run isabelle with option -m HOL to get back to
  4813 the original Gordon/HOL-style output;
  4814 
  4815 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4816 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4817 
  4818 * HOL basic syntax simplified (more orthogonal): all variants of
  4819 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4820 Eps operator is provided as well: "SOME x. P[x]";
  4821 
  4822 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4823 
  4824 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4825 thus available for user theories;
  4826 
  4827 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4828 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4829 time;
  4830 
  4831 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4832 several times and then mp;
  4833 
  4834 
  4835 *** LK ***
  4836 
  4837 * the notation <<...>> is now available as a notation for sequences of
  4838 formulas;
  4839 
  4840 * the simplifier is now installed
  4841 
  4842 * the axiom system has been generalized (thanks to Soren Heilmann)
  4843 
  4844 * the classical reasoner now has a default rule database
  4845 
  4846 
  4847 *** ZF ***
  4848 
  4849 * new primrec section allows primitive recursive functions to be given
  4850 directly (as in HOL) over datatypes and the natural numbers;
  4851 
  4852 * new tactics induct_tac and exhaust_tac for induction (or case
  4853 analysis) over datatypes and the natural numbers;
  4854 
  4855 * the datatype declaration of type T now defines the recursor T_rec;
  4856 
  4857 * simplification automatically does freeness reasoning for datatype
  4858 constructors;
  4859 
  4860 * automatic type-inference, with AddTCs command to insert new
  4861 type-checking rules;
  4862 
  4863 * datatype introduction rules are now added as Safe Introduction rules
  4864 to the claset;
  4865 
  4866 * the syntax "if P then x else y" is now available in addition to
  4867 if(P,x,y);
  4868 
  4869 
  4870 *** Internal programming interfaces ***
  4871 
  4872 * tuned simplifier trace output; new flag debug_simp;
  4873 
  4874 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4875 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4876 
  4877 * AxClass.axclass_tac lost the theory argument;
  4878 
  4879 * tuned current_goals_markers semantics: begin / end goal avoids
  4880 printing empty lines;
  4881 
  4882 * removed prs and prs_fn hook, which was broken because it did not
  4883 include \n in its semantics, forcing writeln to add one
  4884 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4885 string -> unit if you really want to output text without newline;
  4886 
  4887 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4888 plain output, interface builders may have to enable 'isabelle_font'
  4889 mode to get Isabelle font glyphs as before;
  4890 
  4891 * refined token_translation interface; INCOMPATIBILITY: output length
  4892 now of type real instead of int;
  4893 
  4894 * theory loader actions may be traced via new ThyInfo.add_hook
  4895 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4896 your own database of information attached to *whole* theories -- as
  4897 opposed to intra-theory data slots offered via TheoryDataFun;
  4898 
  4899 * proper handling of dangling sort hypotheses (at last!);
  4900 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4901 extra sort hypotheses that can be witnessed from the type signature;
  4902 the force_strip_shyps flag is gone, any remaining shyps are simply
  4903 left in the theorem (with a warning issued by strip_shyps_warning);
  4904 
  4905 
  4906 
  4907 New in Isabelle98-1 (October 1998)
  4908 ----------------------------------
  4909 
  4910 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4911 
  4912 * several changes of automated proof tools;
  4913 
  4914 * HOL: major changes to the inductive and datatype packages, including
  4915 some minor incompatibilities of theory syntax;
  4916 
  4917 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4918 called `inj_on';
  4919 
  4920 * HOL: removed duplicate thms in Arith:
  4921   less_imp_add_less  should be replaced by  trans_less_add1
  4922   le_imp_add_le      should be replaced by  trans_le_add1
  4923 
  4924 * HOL: unary minus is now overloaded (new type constraints may be
  4925 required);
  4926 
  4927 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4928 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4929 now taken as an integer constant.
  4930 
  4931 * Pure: ML function 'theory_of' renamed to 'theory';
  4932 
  4933 
  4934 *** Proof tools ***
  4935 
  4936 * Simplifier:
  4937   1. Asm_full_simp_tac is now more aggressive.
  4938      1. It will sometimes reorient premises if that increases their power to
  4939         simplify.
  4940      2. It does no longer proceed strictly from left to right but may also
  4941         rotate premises to achieve further simplification.
  4942      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4943      old Asm_full_simp_tac in that it does not rotate premises.
  4944   2. The simplifier now knows a little bit about nat-arithmetic.
  4945 
  4946 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4947 allows for selected deletion of wrappers, by introduction of names for
  4948 wrapper functionals.  This implies that addbefore, addSbefore,
  4949 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4950 and that adding two tactics with the same name overwrites the first
  4951 one (emitting a warning).
  4952   type wrapper = (int -> tactic) -> (int -> tactic)
  4953   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4954   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4955   delWrapper, delSWrapper: claset *  string            -> claset
  4956   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4957 
  4958 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4959 semantics; addbefore now affects only the unsafe part of step_tac
  4960 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4961 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4962 by Force_tac;
  4963 
  4964 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4965 compWrapper; added safe wrapper (and access functions for it);
  4966 
  4967 * HOL/split_all_tac is now much faster and fails if there is nothing
  4968 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4969 and the names of the automatically generated variables have changed.
  4970 split_all_tac has moved within claset() from unsafe wrappers to safe
  4971 wrappers, which means that !!-bound variables are split much more
  4972 aggressively, and safe_tac and clarify_tac now split such variables.
  4973 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4974 Note: the same holds for record_split_tac, which does the job of
  4975 split_all_tac for record fields.
  4976 
  4977 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4978 permanently to the default simpset using Addsplits just like
  4979 Addsimps. They can be removed via Delsplits just like
  4980 Delsimps. Lower-case versions are also available.
  4981 
  4982 * HOL/Simplifier: The rule split_if is now part of the default
  4983 simpset. This means that the simplifier will eliminate all occurrences
  4984 of if-then-else in the conclusion of a goal. To prevent this, you can
  4985 either remove split_if completely from the default simpset by
  4986 `Delsplits [split_if]' or remove it in a specific call of the
  4987 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4988 other case splitting rules to/from the default simpset: every datatype
  4989 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4990 t is the name of the datatype).
  4991 
  4992 * Classical reasoner / Simplifier combination: new force_tac (and
  4993 derivatives Force_tac, force) combines rewriting and classical
  4994 reasoning (and whatever other tools) similarly to auto_tac, but is
  4995 aimed to solve the given subgoal completely.
  4996 
  4997 
  4998 *** General ***
  4999 
  5000 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5001 and `goalw': the theory is no longer needed as an explicit argument -
  5002 the current theory context is used; assumptions are no longer returned
  5003 at the ML-level unless one of them starts with ==> or !!; it is
  5004 recommended to convert to these new commands using isatool fixgoal
  5005 (backup your sources first!);
  5006 
  5007 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5008 the current theory context, and 'theory' to lookup stored theories;
  5009 
  5010 * new theory section 'locale' for declaring constants, assumptions and
  5011 definitions that have local scope;
  5012 
  5013 * new theory section 'nonterminals' for purely syntactic types;
  5014 
  5015 * new theory section 'setup' for generic ML setup functions
  5016 (e.g. package initialization);
  5017 
  5018 * the distribution now includes Isabelle icons: see
  5019 lib/logo/isabelle-{small,tiny}.xpm;
  5020 
  5021 * isatool install - install binaries with absolute references to
  5022 ISABELLE_HOME/bin;
  5023 
  5024 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5025 
  5026 * print mode 'emacs' reserved for Isamode;
  5027 
  5028 * support multiple print (ast) translations per constant name;
  5029 
  5030 * theorems involving oracles are now printed with a suffixed [!];
  5031 
  5032 
  5033 *** HOL ***
  5034 
  5035 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5036 
  5037 * HOL/inductive package reorganized and improved: now supports mutual
  5038 definitions such as
  5039 
  5040   inductive EVEN ODD
  5041     intrs
  5042       null "0 : EVEN"
  5043       oddI "n : EVEN ==> Suc n : ODD"
  5044       evenI "n : ODD ==> Suc n : EVEN"
  5045 
  5046 new theorem list "elims" contains an elimination rule for each of the
  5047 recursive sets; inductive definitions now handle disjunctive premises
  5048 correctly (also ZF);
  5049 
  5050 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5051 "mutual_induct" no longer exists - the induction rule is always
  5052 contained in "induct";
  5053 
  5054 
  5055 * HOL/datatype package re-implemented and greatly improved: now
  5056 supports mutually recursive datatypes such as
  5057 
  5058   datatype
  5059     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5060             | SUM ('a aexp) ('a aexp)
  5061             | DIFF ('a aexp) ('a aexp)
  5062             | NUM 'a
  5063   and
  5064     'a bexp = LESS ('a aexp) ('a aexp)
  5065             | AND ('a bexp) ('a bexp)
  5066             | OR ('a bexp) ('a bexp)
  5067 
  5068 as well as indirectly recursive datatypes such as
  5069 
  5070   datatype
  5071     ('a, 'b) term = Var 'a
  5072                   | App 'b ((('a, 'b) term) list)
  5073 
  5074 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5075 induction on mutually / indirectly recursive datatypes.
  5076 
  5077 Primrec equations are now stored in theory and can be accessed via
  5078 <function_name>.simps.
  5079 
  5080 INCOMPATIBILITIES:
  5081 
  5082   - Theories using datatypes must now have theory Datatype as an
  5083     ancestor.
  5084   - The specific <typename>.induct_tac no longer exists - use the
  5085     generic induct_tac instead.
  5086   - natE has been renamed to nat.exhaust - use exhaust_tac
  5087     instead of res_inst_tac ... natE. Note that the variable
  5088     names in nat.exhaust differ from the names in natE, this
  5089     may cause some "fragile" proofs to fail.
  5090   - The theorems split_<typename>_case and split_<typename>_case_asm
  5091     have been renamed to <typename>.split and <typename>.split_asm.
  5092   - Since default sorts of type variables are now handled correctly,
  5093     some datatype definitions may have to be annotated with explicit
  5094     sort constraints.
  5095   - Primrec definitions no longer require function name and type
  5096     of recursive argument.
  5097 
  5098 Consider using isatool fixdatatype to adapt your theories and proof
  5099 scripts to the new package (backup your sources first!).
  5100 
  5101 
  5102 * HOL/record package: considerably improved implementation; now
  5103 includes concrete syntax for record types, terms, updates; theorems
  5104 for surjective pairing and splitting !!-bound record variables; proof
  5105 support is as follows:
  5106 
  5107   1) standard conversions (selectors or updates applied to record
  5108 constructor terms) are part of the standard simpset;
  5109 
  5110   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5111 made part of standard simpset and claset via addIffs;
  5112 
  5113   3) a tactic for record field splitting (record_split_tac) is part of
  5114 the standard claset (addSWrapper);
  5115 
  5116 To get a better idea about these rules you may retrieve them via
  5117 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5118 the name of your record type.
  5119 
  5120 The split tactic 3) conceptually simplifies by the following rule:
  5121 
  5122   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5123 
  5124 Thus any record variable that is bound by meta-all will automatically
  5125 blow up into some record constructor term, consequently the
  5126 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5127 solve record problems automatically.
  5128 
  5129 
  5130 * reorganized the main HOL image: HOL/Integ and String loaded by
  5131 default; theory Main includes everything;
  5132 
  5133 * automatic simplification of integer sums and comparisons, using cancellation;
  5134 
  5135 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5136 
  5137 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5138 
  5139 * many new identities for unions, intersections, set difference, etc.;
  5140 
  5141 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5142 called split_if, split_split, split_sum_case and split_nat_case (to go
  5143 with add/delsplits);
  5144 
  5145 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5146 (?x::unit) = (); this is made part of the default simpset, which COULD
  5147 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5148 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5149 unit_abs_eta_conv is added in order to counter the effect of
  5150 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5151 %u.f();
  5152 
  5153 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5154 makes more sense);
  5155 
  5156 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5157   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5158   disjointness reasoning but breaking a few old proofs.
  5159 
  5160 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5161 to 'converse' from 'inverse' (for compatibility with ZF and some
  5162 literature);
  5163 
  5164 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5165 the well-founded relation;
  5166 
  5167 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5168     Compl A.  The "Compl" syntax remains available as input syntax for this
  5169     release ONLY.
  5170 
  5171 * HOL/Update: new theory of function updates:
  5172     f(a:=b) == %x. if x=a then b else f x
  5173 may also be iterated as in f(a:=b,c:=d,...);
  5174 
  5175 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5176 
  5177 * HOL/List:
  5178   - new function list_update written xs[i:=v] that updates the i-th
  5179     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5180   - new function `upt' written [i..j(] which generates the list
  5181     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5182     bound write [i..j], which is a shorthand for [i..j+1(].
  5183   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5184 
  5185 * HOL/Arith:
  5186   - removed 'pred' (predecessor) function;
  5187   - generalized some theorems about n-1;
  5188   - many new laws about "div" and "mod";
  5189   - new laws about greatest common divisors (see theory ex/Primes);
  5190 
  5191 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5192 instead of "inverse";
  5193 
  5194 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5195   of the multiset ordering;
  5196 
  5197 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5198   (not included by default);
  5199 
  5200 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5201 
  5202 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5203   programs, i.e. different program variables may have different types.
  5204 
  5205 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5206   [previously, this check worked only if the rewrite rule was unconditional]
  5207   Now rew can involve either definitions or equalities (either == or =).
  5208 
  5209 
  5210 *** ZF ***
  5211 
  5212 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5213   only the theorems proved on ZF.ML;
  5214 
  5215 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5216   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5217   disjointness reasoning but breaking a few old proofs.
  5218 
  5219 * ZF/Update: new theory of function updates
  5220     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5221   may also be iterated as in f(a:=b,c:=d,...);
  5222 
  5223 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5224 
  5225 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5226   [previously, this check worked only if the rewrite rule was unconditional]
  5227   Now rew can involve either definitions or equalities (either == or =).
  5228 
  5229 * case_tac provided for compatibility with HOL
  5230     (like the old excluded_middle_tac, but with subgoals swapped)
  5231 
  5232 
  5233 *** Internal programming interfaces ***
  5234 
  5235 * Pure: several new basic modules made available for general use, see
  5236 also src/Pure/README;
  5237 
  5238 * improved the theory data mechanism to support encapsulation (data
  5239 kind name replaced by private Object.kind, acting as authorization
  5240 key); new type-safe user interface via functor TheoryDataFun; generic
  5241 print_data function becomes basically useless;
  5242 
  5243 * removed global_names compatibility flag -- all theory declarations
  5244 are qualified by default;
  5245 
  5246 * module Pure/Syntax now offers quote / antiquote translation
  5247 functions (useful for Hoare logic etc. with implicit dependencies);
  5248 see HOL/ex/Antiquote for an example use;
  5249 
  5250 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5251 cterm -> thm;
  5252 
  5253 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5254 subgoal;
  5255 
  5256 * Display.print_goals function moved to Locale.print_goals;
  5257 
  5258 * standard print function for goals supports current_goals_markers
  5259 variable for marking begin of proof, end of proof, start of goal; the
  5260 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5261 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5262 for example;
  5263 
  5264 
  5265 
  5266 New in Isabelle98 (January 1998)
  5267 --------------------------------
  5268 
  5269 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5270 
  5271 * changed lexical syntax of terms / types: dots made part of long
  5272 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5273 
  5274 * simpset (and claset) reference variable replaced by functions
  5275 simpset / simpset_ref;
  5276 
  5277 * no longer supports theory aliases (via merge) and non-trivial
  5278 implicit merge of thms' signatures;
  5279 
  5280 * most internal names of constants changed due to qualified names;
  5281 
  5282 * changed Pure/Sequence interface (see Pure/seq.ML);
  5283 
  5284 
  5285 *** General Changes ***
  5286 
  5287 * hierachically structured name spaces (for consts, types, axms, thms
  5288 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5289 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5290 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5291 long_names for fully qualified output names; NOTE: ML programs
  5292 (special tactics, packages etc.) referring to internal names may have
  5293 to be adapted to cope with fully qualified names; in case of severe
  5294 backward campatibility problems try setting 'global_names' at compile
  5295 time to have enrything declared within a flat name space; one may also
  5296 fine tune name declarations in theories via the 'global' and 'local'
  5297 section;
  5298 
  5299 * reimplemented the implicit simpset and claset using the new anytype
  5300 data filed in signatures; references simpset:simpset ref etc. are
  5301 replaced by functions simpset:unit->simpset and
  5302 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5303 to patch your ML files accordingly;
  5304 
  5305 * HTML output now includes theory graph data for display with Java
  5306 applet or isatool browser; data generated automatically via isatool
  5307 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5308 
  5309 * defs may now be conditional; improved rewrite_goals_tac to handle
  5310 conditional equations;
  5311 
  5312 * defs now admits additional type arguments, using TYPE('a) syntax;
  5313 
  5314 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5315 creates a new theory node; implicit merge of thms' signatures is
  5316 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5317 transfer:theory->thm->thm in (rare) cases;
  5318 
  5319 * improved handling of draft signatures / theories; draft thms (and
  5320 ctyps, cterms) are automatically promoted to real ones;
  5321 
  5322 * slightly changed interfaces for oracles: admit many per theory, named
  5323 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5324 
  5325 * print_goals: optional output of const types (set show_consts and
  5326 show_types);
  5327 
  5328 * improved output of warnings (###) and errors (***);
  5329 
  5330 * subgoal_tac displays a warning if the new subgoal has type variables;
  5331 
  5332 * removed old README and Makefiles;
  5333 
  5334 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5335 
  5336 * removed obsolete init_pps and init_database;
  5337 
  5338 * deleted the obsolete tactical STATE, which was declared by
  5339     fun STATE tacfun st = tacfun st st;
  5340 
  5341 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5342 (which abbreviates $HOME);
  5343 
  5344 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5345 use isatool fixseq to adapt your ML programs (this works for fully
  5346 qualified references to the Sequence structure only!);
  5347 
  5348 * use_thy no longer requires writable current directory; it always
  5349 reloads .ML *and* .thy file, if either one is out of date;
  5350 
  5351 
  5352 *** Classical Reasoner ***
  5353 
  5354 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5355 tactics that use classical reasoning to simplify a subgoal without
  5356 splitting it into several subgoals;
  5357 
  5358 * Safe_tac: like safe_tac but uses the default claset;
  5359 
  5360 
  5361 *** Simplifier ***
  5362 
  5363 * added simplification meta rules:
  5364     (asm_)(full_)simplify: simpset -> thm -> thm;
  5365 
  5366 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5367 logics (again);
  5368 
  5369 * added prems argument to simplification procedures;
  5370 
  5371 * HOL, FOL, ZF: added infix function `addsplits':
  5372   instead of `<simpset> setloop (split_tac <thms>)'
  5373   you can simply write `<simpset> addsplits <thms>'
  5374 
  5375 
  5376 *** Syntax ***
  5377 
  5378 * TYPE('a) syntax for type reflection terms;
  5379 
  5380 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5381 
  5382 * pretty printer: changed order of mixfix annotation preference (again!);
  5383 
  5384 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5385 
  5386 
  5387 *** HOL ***
  5388 
  5389 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5390   with `addloop' of the simplifier to faciliate case splitting in premises.
  5391 
  5392 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5393 
  5394 * HOL/Auth: new protocol proofs including some for the Internet
  5395   protocol TLS;
  5396 
  5397 * HOL/Map: new theory of `maps' a la VDM;
  5398 
  5399 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5400 cancelling out common nat summands from =, <, <= (in)equalities, or
  5401 differences; simplification procedures nat_cancel_factor for
  5402 cancelling common factor from =, <, <= (in)equalities over natural
  5403 sums; nat_cancel contains both kinds of procedures, it is installed by
  5404 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5405 
  5406 * HOL/simplifier: terms of the form
  5407   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5408   are rewritten to
  5409   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5410   and those of the form
  5411   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5412   are rewritten to
  5413   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5414 
  5415 * HOL/datatype
  5416   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5417 
  5418   P(t_case f1 ... fn x) =
  5419      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5420         ...
  5421        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5422      )
  5423 
  5424   and a theorem `split_t_case_asm' of the form
  5425 
  5426   P(t_case f1 ... fn x) =
  5427     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5428         ...
  5429        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5430      )
  5431   which can be added to a simpset via `addsplits'. The existing theorems
  5432   expand_list_case and expand_option_case have been renamed to
  5433   split_list_case and split_option_case.
  5434 
  5435 * HOL/Arithmetic:
  5436   - `pred n' is automatically converted to `n-1'.
  5437     Users are strongly encouraged not to use `pred' any longer,
  5438     because it will disappear altogether at some point.
  5439   - Users are strongly encouraged to write "0 < n" rather than
  5440     "n ~= 0". Theorems and proof tools have been modified towards this
  5441     `standard'.
  5442 
  5443 * HOL/Lists:
  5444   the function "set_of_list" has been renamed "set" (and its theorems too);
  5445   the function "nth" now takes its arguments in the reverse order and
  5446   has acquired the infix notation "!" as in "xs!n".
  5447 
  5448 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5449 
  5450 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5451   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5452 
  5453 * HOL/record: extensible records with schematic structural subtyping
  5454 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5455 still lacks various theorems and concrete record syntax;
  5456 
  5457 
  5458 *** HOLCF ***
  5459 
  5460 * removed "axioms" and "generated by" sections;
  5461 
  5462 * replaced "ops" section by extended "consts" section, which is capable of
  5463   handling the continuous function space "->" directly;
  5464 
  5465 * domain package:
  5466   . proves theorems immediately and stores them in the theory,
  5467   . creates hierachical name space,
  5468   . now uses normal mixfix annotations (instead of cinfix...),
  5469   . minor changes to some names and values (for consistency),
  5470   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5471   . separator between mutual domain defs: changed "," to "and",
  5472   . improved handling of sort constraints;  now they have to
  5473     appear on the left-hand side of the equations only;
  5474 
  5475 * fixed LAM <x,y,zs>.b syntax;
  5476 
  5477 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5478 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5479 
  5480 
  5481 *** FOL and ZF ***
  5482 
  5483 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5484   with `addloop' of the simplifier to faciliate case splitting in premises.
  5485 
  5486 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5487 in HOL, they strip ALL and --> from proved theorems;
  5488 
  5489 
  5490 
  5491 New in Isabelle94-8 (May 1997)
  5492 ------------------------------
  5493 
  5494 *** General Changes ***
  5495 
  5496 * new utilities to build / run / maintain Isabelle etc. (in parts
  5497 still somewhat experimental); old Makefiles etc. still functional;
  5498 
  5499 * new 'Isabelle System Manual';
  5500 
  5501 * INSTALL text, together with ./configure and ./build scripts;
  5502 
  5503 * reimplemented type inference for greater efficiency, better error
  5504 messages and clean internal interface;
  5505 
  5506 * prlim command for dealing with lots of subgoals (an easier way of
  5507 setting goals_limit);
  5508 
  5509 
  5510 *** Syntax ***
  5511 
  5512 * supports alternative (named) syntax tables (parser and pretty
  5513 printer); internal interface is provided by add_modesyntax(_i);
  5514 
  5515 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5516 be used in conjunction with the Isabelle symbol font; uses the
  5517 "symbols" syntax table;
  5518 
  5519 * added token_translation interface (may translate name tokens in
  5520 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5521 the current print_mode); IMPORTANT: user print translation functions
  5522 are responsible for marking newly introduced bounds
  5523 (Syntax.mark_boundT);
  5524 
  5525 * token translations for modes "xterm" and "xterm_color" that display
  5526 names in bold, underline etc. or colors (which requires a color
  5527 version of xterm);
  5528 
  5529 * infixes may now be declared with names independent of their syntax;
  5530 
  5531 * added typed_print_translation (like print_translation, but may
  5532 access type of constant);
  5533 
  5534 
  5535 *** Classical Reasoner ***
  5536 
  5537 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5538 some limitations.  Blast_tac...
  5539   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5540   + ignores elimination rules that don't have the correct format
  5541         (the conclusion MUST be a formula variable)
  5542   + ignores types, which can make HOL proofs fail
  5543   + rules must not require higher-order unification, e.g. apply_type in ZF
  5544     [message "Function Var's argument not a bound variable" relates to this]
  5545   + its proof strategy is more general but can actually be slower
  5546 
  5547 * substitution with equality assumptions no longer permutes other
  5548 assumptions;
  5549 
  5550 * minor changes in semantics of addafter (now called addaltern); renamed
  5551 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5552 (and access functions for it);
  5553 
  5554 * improved combination of classical reasoner and simplifier:
  5555   + functions for handling clasimpsets
  5556   + improvement of addss: now the simplifier is called _after_ the
  5557     safe steps.
  5558   + safe variant of addss called addSss: uses safe simplifications
  5559     _during_ the safe steps. It is more complete as it allows multiple
  5560     instantiations of unknowns (e.g. with slow_tac).
  5561 
  5562 *** Simplifier ***
  5563 
  5564 * added interface for simplification procedures (functions that
  5565 produce *proven* rewrite rules on the fly, depending on current
  5566 redex);
  5567 
  5568 * ordering on terms as parameter (used for ordered rewriting);
  5569 
  5570 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5571 
  5572 * the solver is now split into a safe and an unsafe part.
  5573 This should be invisible for the normal user, except that the
  5574 functions setsolver and addsolver have been renamed to setSolver and
  5575 addSolver; added safe_asm_full_simp_tac;
  5576 
  5577 
  5578 *** HOL ***
  5579 
  5580 * a generic induction tactic `induct_tac' which works for all datatypes and
  5581 also for type `nat';
  5582 
  5583 * a generic case distinction tactic `exhaust_tac' which works for all
  5584 datatypes and also for type `nat';
  5585 
  5586 * each datatype comes with a function `size';
  5587 
  5588 * patterns in case expressions allow tuple patterns as arguments to
  5589 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5590 
  5591 * primrec now also works with type nat;
  5592 
  5593 * recdef: a new declaration form, allows general recursive functions to be
  5594 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5595 
  5596 * the constant for negation has been renamed from "not" to "Not" to
  5597 harmonize with FOL, ZF, LK, etc.;
  5598 
  5599 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5600 infinite lists;
  5601 
  5602 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5603 
  5604 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5605 problems in commutative rings, using axiomatic type classes for + and *;
  5606 
  5607 * more examples in HOL/MiniML and HOL/Auth;
  5608 
  5609 * more default rewrite rules for quantifiers, union/intersection;
  5610 
  5611 * a new constant `arbitrary == @x.False';
  5612 
  5613 * HOLCF/IOA replaces old HOL/IOA;
  5614 
  5615 * HOLCF changes: derived all rules and arities
  5616   + axiomatic type classes instead of classes
  5617   + typedef instead of faking type definitions
  5618   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5619   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5620   + eliminated the types void, one, tr
  5621   + use unit lift and bool lift (with translations) instead of one and tr
  5622   + eliminated blift from Lift3.thy (use Def instead of blift)
  5623   all eliminated rules are derived as theorems --> no visible changes ;
  5624 
  5625 
  5626 *** ZF ***
  5627 
  5628 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5629 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5630 as ZF_cs addSIs [equalityI];
  5631 
  5632 
  5633 
  5634 New in Isabelle94-7 (November 96)
  5635 ---------------------------------
  5636 
  5637 * allowing negative levels (as offsets) in prlev and choplev;
  5638 
  5639 * super-linear speedup for large simplifications;
  5640 
  5641 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5642 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5643 FAIL); can suppress it using the command Delsimps (ex_simps @
  5644 all_simps); De Morgan laws are also now included, by default;
  5645 
  5646 * improved printing of ==>  :  ~:
  5647 
  5648 * new object-logic "Sequents" adds linear logic, while replacing LK
  5649 and Modal (thanks to Sara Kalvala);
  5650 
  5651 * HOL/Auth: correctness proofs for authentication protocols;
  5652 
  5653 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5654 examples on HOL/Auth);
  5655 
  5656 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5657 the rewriter and classical reasoner simultaneously;
  5658 
  5659 * function uresult no longer returns theorems in "standard" format;
  5660 regain previous version by: val uresult = standard o uresult;
  5661 
  5662 
  5663 
  5664 New in Isabelle94-6
  5665 -------------------
  5666 
  5667 * oracles -- these establish an interface between Isabelle and trusted
  5668 external reasoners, which may deliver results as theorems;
  5669 
  5670 * proof objects (in particular record all uses of oracles);
  5671 
  5672 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5673 
  5674 * "constdefs" section in theory files;
  5675 
  5676 * "primrec" section (HOL) no longer requires names;
  5677 
  5678 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5679 
  5680 
  5681 
  5682 New in Isabelle94-5
  5683 -------------------
  5684 
  5685 * reduced space requirements;
  5686 
  5687 * automatic HTML generation from theories;
  5688 
  5689 * theory files no longer require "..." (quotes) around most types;
  5690 
  5691 * new examples, including two proofs of the Church-Rosser theorem;
  5692 
  5693 * non-curried (1994) version of HOL is no longer distributed;
  5694 
  5695 
  5696 
  5697 New in Isabelle94-4
  5698 -------------------
  5699 
  5700 * greatly reduced space requirements;
  5701 
  5702 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5703 
  5704 * searchable theorem database (see the section "Retrieving theorems" on
  5705 page 8 of the Reference Manual);
  5706 
  5707 * new examples, including Grabczewski's monumental case study of the
  5708 Axiom of Choice;
  5709 
  5710 * The previous version of HOL renamed to Old_HOL;
  5711 
  5712 * The new version of HOL (previously called CHOL) uses a curried syntax
  5713 for functions.  Application looks like f a b instead of f(a,b);
  5714 
  5715 * Mutually recursive inductive definitions finally work in HOL;
  5716 
  5717 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5718 translates to the operator "split";
  5719 
  5720 
  5721 
  5722 New in Isabelle94-3
  5723 -------------------
  5724 
  5725 * new infix operator, addss, allowing the classical reasoner to
  5726 perform simplification at each step of its search.  Example:
  5727         fast_tac (cs addss ss)
  5728 
  5729 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5730 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5731 look like (a,b) instead of <a,b>;
  5732 
  5733 * PLEASE NOTE: CHOL will eventually replace HOL!
  5734 
  5735 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5736 It translates to the operator "split".  A new theory of integers is available;
  5737 
  5738 * In ZF, integer numerals now denote two's-complement binary integers.
  5739 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5740 
  5741 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5742 of the Axiom of Choice;
  5743 
  5744 
  5745 
  5746 New in Isabelle94-2
  5747 -------------------
  5748 
  5749 * Significantly faster resolution;
  5750 
  5751 * the different sections in a .thy file can now be mixed and repeated
  5752 freely;
  5753 
  5754 * Database of theorems for FOL, HOL and ZF.  New
  5755 commands including qed, qed_goal and bind_thm store theorems in the database.
  5756 
  5757 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5758 a given theory (thms_of), or find out what theory a theorem was proved in
  5759 (theory_of_thm);
  5760 
  5761 * Bugs fixed in the inductive definition and datatype packages;
  5762 
  5763 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5764 and HOL_dup_cs obsolete;
  5765 
  5766 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5767 have been removed;
  5768 
  5769 * Simpler definition of function space in ZF;
  5770 
  5771 * new results about cardinal and ordinal arithmetic in ZF;
  5772 
  5773 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5774 types;
  5775 
  5776 :mode=text:wrap=hard:maxLineLen=72:
  5777 
  5778 
  5779 $Id$