NEWS
author haftmann
Tue Feb 03 21:26:21 2009 +0100 (2009-02-03 ago)
changeset 29797 08ef36ed2f8a
parent 29788 1b80ebe713a4
child 29805 a5da150bd0ab
permissions -rw-r--r--
handling type classes without parameters
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Simplified main Isabelle executables, with less surprises on
    10 case-insensitive file-systems (such as Mac OS).
    11 
    12   - The main Isabelle tool wrapper is now called "isabelle" instead of
    13     "isatool."
    14 
    15   - The former "isabelle" alias for "isabelle-process" has been
    16     removed (should rarely occur to regular users).
    17 
    18   - The former "isabelle-interface" and its alias "Isabelle" have been
    19     removed (interfaces are now regular Isabelle tools).
    20 
    21 Within scripts and make files, the Isabelle environment variables
    22 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
    23 respectively.  (The latter are still available as legacy feature.)
    24 
    25 The old isabelle-interface wrapper could react in confusing ways if
    26 the interface was uninstalled or changed otherwise.  Individual
    27 interface tool configuration is now more explicit, see also the
    28 Isabelle system manual.  In particular, Proof General is now available
    29 via "isabelle emacs".
    30 
    31 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
    32 purge installed copies of Isabelle executables and re-run "isabelle
    33 install -p ...", or use symlinks.
    34 
    35 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
    36 old ~/isabelle, which was slightly non-standard and apt cause
    37 surprises on case-insensitive file-systems.
    38 
    39 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
    40 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
    41 care is required when using older releases of Isabelle.  Note that
    42 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
    43 Isabelle distribution.
    44 
    45 * Proofs of fully specified statements are run in parallel on
    46 multi-core systems.  A speedup factor of 2-3 can be expected on a
    47 regular 4-core machine, if the initial heap space is made reasonably
    48 large (cf. Poly/ML option -H).  [Poly/ML 5.2.1 or later]
    49 
    50 * The Isabelle System Manual (system) has been updated, with formally
    51 checked references as hyperlinks.
    52 
    53 * Generalized Isar history, with support for linear undo, direct state
    54 addressing etc.
    55 
    56 * Recovered hiding of consts, which was accidentally broken in
    57 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
    58 makes c inaccessible; consider using ``hide (open) const c'' instead.
    59 
    60 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
    61 interface instead.
    62 
    63 * There is a new syntactic category "float_const" for signed decimal
    64 fractions (e.g. 123.45 or -123.45).
    65 
    66 
    67 *** Pure ***
    68 
    69 * Class declaration: sc. "base sort" must not be given in import list
    70 any longer but is inferred from the specification.  Particularly in HOL,
    71 write
    72 
    73     class foo = ...     instead of      class foo = type + ...
    74 
    75 * Type binding gradually replaces formerly used type bstring for names
    76 to be bound.  Name space interface for declarations has been simplified:
    77 
    78   NameSpace.declare: NameSpace.naming
    79     -> binding -> NameSpace.T -> string * NameSpace.T
    80   NameSpace.bind: NameSpace.naming
    81     -> binding * 'a -> 'a NameSpace.table -> string * 'a NameSpace.table
    82          (*exception Symtab.DUP*)
    83 
    84 See further modules src/Pure/General/binding.ML and
    85 src/Pure/General/name_space.ML
    86 
    87 * Module moves in repository:
    88     src/Pure/Tools/value.ML ~> src/Tools/
    89     src/Pure/Tools/quickcheck.ML ~> src/Tools/
    90 
    91 * Slightly more coherent Pure syntax, with updated documentation in
    92 isar-ref manual.  Removed locales meta_term_syntax and
    93 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
    94 INCOMPATIBILITY in rare situations.
    95 
    96 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
    97 hypotheses.  Sorts required in the course of reasoning need to be
    98 covered by the constraints in the initial statement, completed by the
    99 type instance information of the background theory.  Non-trivial sort
   100 hypotheses, which rarely occur in practice, may be specified via
   101 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   102 
   103   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   104 
   105 The result contains an implicit sort hypotheses as before --
   106 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   107 normalization.
   108 
   109 * Changed defaults for unify configuration options:
   110 
   111   unify_trace_bound = 50 (formerly 25)
   112   unify_search_bound = 60 (formerly 30)
   113 
   114 * Different bookkeeping for code equations:
   115   a) On theory merge, the last set of code equations for a particular constant
   116      is taken (in accordance with the policy applied by other parts of the
   117      code generator framework).
   118   b) Code equations stemming from explicit declarations (e.g. code attribute)
   119      gain priority over default code equations stemming from definition, primrec,
   120      fun etc.
   121   INCOMPATIBILITY.
   122 
   123 * Global versions of theorems stemming from classes do not carry
   124 a parameter prefix any longer.  INCOMPATIBILITY.
   125 
   126 * Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   127 In existing theorem specifications replace the includes element by the
   128 respective context elements of the included locale, omitting those that
   129 are already present in the theorem specification.  Multiple assume
   130 elements of a locale should be replaced by a single one involving the
   131 locale predicate.  In the proof body, declarations (most notably
   132 theorems) may be regained by interpreting the respective locales in the
   133 proof context as required (command "interpret").
   134 If using "includes" in replacement of a target solely because the
   135 parameter types in the theorem are not as general as in the target,
   136 consider declaring a new locale with additional type constraints on the
   137 parameters (context element "constrains").
   138 
   139 * Dropped "locale (open)".  INCOMPATIBILITY.
   140 
   141 * Interpretation commands no longer attempt to simplify goal.
   142 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   143 methods intro_locales and unfold_locales to clarify.
   144 
   145 * Interpretation commands no longer accept interpretation attributes.
   146 INCOMPATBILITY.
   147 
   148 * Complete re-implementation of locales.  INCOMPATIBILITY.
   149 The most important changes are listed below.  See documentation
   150 (forthcoming) and tutorial (also forthcoming) for details.
   151 
   152 - In locale expressions, instantiation replaces renaming.  Parameters
   153 must be declared in a for clause.  To aid compatibility with previous
   154 parameter inheritance, in locale declarations, parameters that are not
   155 'touched' (instantiation position "_" or omitted) are implicitly added
   156 with their syntax at the beginning of the for clause.
   157 
   158 - Syntax from abbreviations and definitions in locales is available in
   159 locale expressions and context elements.  The latter is particularly
   160 useful in locale declarations.
   161 
   162 - More flexible mechanisms to qualify names generated by locale
   163 expressions.  Qualifiers (prefixes) may be specified in locale
   164 expressions.  Available are normal qualifiers (syntax "name:") and strict
   165 qualifiers (syntax "name!:").  The latter must occur in name references
   166 and are useful to avoid accidental hiding of names, the former are
   167 optional.  Qualifiers derived from the parameter names of a locale are no
   168 longer generated.
   169 
   170 - "sublocale l < e" replaces "interpretation l < e".  The instantiation
   171 clause in "interpretation" and "interpret" (square brackets) is no
   172 longer available.  Use locale expressions.
   173 
   174 - When converting proof scripts, be sure to replace qualifiers in
   175 "interpretation" and "interpret" by strict qualifiers.  Qualifiers in
   176 locale expressions range over a single locale instance only.
   177 
   178 * Command 'instance': attached definitions no longer accepted.
   179 INCOMPATIBILITY, use proper 'instantiation' target.
   180 
   181 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   182 
   183 * The 'axiomatization' command now only works within a global theory
   184 context.  INCOMPATIBILITY.
   185 
   186 
   187 *** Document preparation ***
   188 
   189 * Antiquotation @{lemma} now imitates a regular terminal proof,
   190 demanding keyword 'by' and supporting the full method expression
   191 syntax just like the Isar command 'by'.
   192 
   193 
   194 *** HOL ***
   195 
   196 * Auxiliary class "itself" has disappeared -- classes without any parameter
   197 are treated as expected by the 'class' command.
   198 
   199 * Theory "Reflection" now resides in HOL/Library.  Common reflection examples
   200 (Cooper, MIR, Ferrack) now in distinct session directory HOL/Reflection.
   201 
   202 * Entry point to Word library now simply named "Word".  INCOMPATIBILITY.
   203 
   204 * Made source layout more coherent with logical distribution
   205 structure:
   206 
   207     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   208     src/HOL/Library/Code_Message.thy ~> src/HOL/
   209     src/HOL/Library/Dense_Linear_Order.thy ~> src/HOL/
   210     src/HOL/Library/GCD.thy ~> src/HOL/
   211     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   212     src/HOL/Library/Parity.thy ~> src/HOL/
   213     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   214     src/HOL/Real/ContNotDenum.thy ~> src/HOL/
   215     src/HOL/Real/Lubs.thy ~> src/HOL/
   216     src/HOL/Real/PReal.thy ~> src/HOL/
   217     src/HOL/Real/Rational.thy ~> src/HOL/
   218     src/HOL/Real/RComplete.thy ~> src/HOL/
   219     src/HOL/Real/RealDef.thy ~> src/HOL/
   220     src/HOL/Real/RealPow.thy ~> src/HOL/
   221     src/HOL/Real/Real.thy ~> src/HOL/
   222     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   223     src/HOL/Complex/Complex.thy ~> src/HOL/
   224     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/
   225     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/
   226     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   227     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   228     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   229     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   230     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   231     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   232     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   233     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   234     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   235     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   236     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   237     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   238     src/HOL/Real/Float ~> src/HOL/Library/
   239     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   240     src/HOL/Real/RealVector.thy ~> src/HOL/
   241 
   242     src/HOL/arith_data.ML ~> src/HOL/Tools
   243     src/HOL/hologic.ML ~> src/HOL/Tools
   244     src/HOL/simpdata.ML ~> src/HOL/Tools
   245     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   246     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   247     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   248     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   249     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   250     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   251     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   252 
   253     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   254     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   255     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   256     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   257     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   258     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   259 
   260 * If methods "eval" and "evaluation" encounter a structured proof state
   261 with !!/==>, only the conclusion is evaluated to True (if possible),
   262 avoiding strange error messages.
   263 
   264 * Simplifier: simproc for let expressions now unfolds if bound variable
   265 occurs at most one time in let expression body.  INCOMPATIBILITY.
   266 
   267 * New classes "top" and "bot" with corresponding operations "top" and "bot"
   268 in theory Orderings;  instantiation of class "complete_lattice" requires
   269 instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   270 
   271 * Changed definition lemma "less_fun_def" in order to provide an instance
   272 for preorders on functions;  use lemma "less_le" instead.  INCOMPATIBILITY.
   273 
   274 * Unified theorem tables for both code code generators.  Thus
   275 [code func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   276 
   277 * Constants "undefined" and "default" replace "arbitrary".  Usually
   278 "undefined" is the right choice to replace "arbitrary", though logically
   279 there is no difference.  INCOMPATIBILITY.
   280 
   281 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   282 Posix processes.  Avoids potentially expensive forking of the ML
   283 process.  New thread-based implementation also works on non-Unix
   284 platforms (Cygwin).  Provers are no longer hardwired, but defined
   285 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   286 commands are covered in the isar-ref manual
   287 
   288 * Wrapper scripts for remote SystemOnTPTP service allows to use
   289 sledgehammer without local ATP installation (Vampire etc.).  See also
   290 ISABELLE_HOME/contrib/SystemOnTPTP and the VAMPIRE_HOME setting
   291 variable.  Other provers may be included via suitable ML wrappers, see
   292 also src/HOL/ATP_Linkup.thy.
   293 
   294 * Normalization by evaluation now allows non-leftlinear equations.
   295 Declare with attribute [code nbe].
   296 
   297 * Command "value" now integrates different evaluation
   298 mechanisms.  The result of the first successful evaluation mechanism
   299 is printed.  In square brackets a particular named evaluation
   300 mechanisms may be specified (currently, [SML], [code] or [nbe]).  See
   301 further src/HOL/ex/Eval_Examples.thy.
   302 
   303 * New method "sizechange" to automate termination proofs using (a
   304 modification of) the size-change principle. Requires SAT solver. See
   305 src/HOL/ex/Termination.thy for examples.
   306 
   307 * HOL/Orderings: class "wellorder" moved here, with explicit induction
   308 rule "less_induct" as assumption.  For instantiation of "wellorder" by
   309 means of predicate "wf", use rule wf_wellorderI.  INCOMPATIBILITY.
   310 
   311 * HOL/Orderings: added class "preorder" as superclass of "order".
   312 INCOMPATIBILITY: Instantiation proofs for order, linorder
   313 etc. slightly changed.  Some theorems named order_class.* now named
   314 preorder_class.*.
   315 
   316 * HOL/Finite_Set: added a new fold combinator of type
   317   ('a => 'b => 'b) => 'b => 'a set => 'b
   318 Occasionally this is more convenient than the old fold combinator which is
   319 now defined in terms of the new one and renamed to fold_image.
   320 
   321 * HOL/Ring_and_Field and HOL/OrderedGroup: The lemmas "group_simps" and
   322 "ring_simps" have been replaced by "algebra_simps" (which can be extended with
   323 further lemmas!). At the moment both still exist but the former will disappear
   324 at some point.
   325 
   326 * HOL/Ring_and_Field and HOL/Divides: Definition of "op dvd" has been
   327 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   328 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   329 of lemmas from Divides has been generalized from nat to class
   330 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   331 renames resulting from duplicate elimination:
   332 
   333     dvd_def_mod ~>          dvd_eq_mod_eq_0
   334     zero_dvd_iff ~>         dvd_0_left_iff
   335     dvd_0 ~>                dvd_0_right
   336     DIVISION_BY_ZERO_DIV ~> div_by_0
   337     DIVISION_BY_ZERO_MOD ~> mod_by_0
   338     mult_div ~>             div_mult_self2_is_id
   339     mult_mod ~>             mod_mult_self2_is_0
   340 
   341 * HOL/Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   342 zlcm (for int); carried together from various gcd/lcm developements in
   343 the HOL Distribution.  zgcd and zlcm replace former igcd and ilcm;
   344 corresponding theorems renamed accordingly.  INCOMPATIBILY.  To
   345 recover tupled syntax, use syntax declarations like:
   346 
   347     hide (open) const gcd
   348     abbreviation gcd where
   349       "gcd == (%(a, b). GCD.gcd a b)"
   350     notation (output)
   351       GCD.gcd ("gcd '(_, _')")
   352 
   353 (analogously for lcm, zgcd, zlcm).
   354 
   355 * HOL/Real/Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   356 
   357 * The real numbers offer decimal input syntax: 12.34 is translated into
   358   1234/10^4. This translation is not reversed upon output.
   359 
   360 * New ML antiquotation @{code}: takes constant as argument, generates
   361 corresponding code in background and inserts name of the corresponding
   362 resulting ML value/function/datatype constructor binding in place.
   363 All occurrences of @{code} with a single ML block are generated
   364 simultaneously.  Provides a generic and safe interface for
   365 instrumentalizing code generation.  See HOL/ex/Code_Antiq for a toy
   366 example, or HOL/Complex/ex/ReflectedFerrack for a more ambitious
   367 application.  In future you ought refrain from ad-hoc compiling
   368 generated SML code on the ML toplevel.  Note that (for technical
   369 reasons) @{code} cannot refer to constants for which user-defined
   370 serializations are set.  Refer to the corresponding ML counterpart
   371 directly in that cases.
   372 
   373 * Integrated image HOL-Complex with HOL.  Entry points Main.thy and
   374 Complex_Main.thy remain as they are.
   375 
   376 * New image HOL-Plain provides a minimal HOL with the most important
   377 tools available (inductive, datatype, primrec, ...).  By convention
   378 the corresponding theory Plain should be ancestor of every further
   379 (library) theory.  Some library theories now have ancestor Plain
   380 (instead of Main), thus theory Main occasionally has to be imported
   381 explicitly.
   382 
   383 * The metis method now fails in the usual manner, rather than raising
   384 an exception, if it determines that it cannot prove the theorem.
   385 
   386 * The metis method no longer fails because the theorem is too trivial
   387 (contains the empty clause).
   388 
   389 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   390 as the structured Isar versions "cases" and "induct", cf. the
   391 corresponding "cases" and "induct" attributes.  Mutual induction rules
   392 are now presented as a list of individual projections
   393 (e.g. foo_bar.inducts for types foo and bar); the old format with
   394 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   395 rare situations a different rule is selected --- notably nested tuple
   396 elimination instead of former prod.exhaust: use explicit (case_tac t
   397 rule: prod.exhaust) here.
   398 
   399 * Attributes "cases", "induct", "coinduct" support "del" option.
   400 
   401 * Removed fact "case_split_thm", which duplicates "case_split".
   402 
   403 * Command 'rep_datatype': instead of theorem names the command now
   404 takes a list of terms denoting the constructors of the type to be
   405 represented as datatype.  The characteristic theorems have to be
   406 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   407 have disappeared in favour of existing ones:
   408 
   409     unit_induct                 ~> unit.induct
   410     prod_induct                 ~> prod.induct
   411     sum_induct                  ~> sum.induct
   412     Suc_Suc_eq                  ~> nat.inject
   413     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   414 
   415 * Library/Nat_Infinity: added addition, numeral syntax and more
   416 instantiations for algebraic structures.  Removed some duplicate
   417 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   418 
   419 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   420 menu.
   421 
   422 
   423 *** HOL-Algebra ***
   424 
   425 * New locales for orders and lattices where the equivalence relation
   426   is not restricted to equality.  INCOMPATIBILITY: all order and
   427   lattice locales use a record structure with field eq for the
   428   equivalence.
   429 
   430 * New theory of factorial domains.
   431 
   432 * Units_l_inv and Units_r_inv are now simprules by default.
   433 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   434 and/or r_inv will now also require deletion of these lemmas.
   435 
   436 * Renamed the following theorems.  INCOMPATIBILITY.
   437 UpperD ~> Upper_memD
   438 LowerD ~> Lower_memD
   439 least_carrier ~> least_closed
   440 greatest_carrier ~> greatest_closed
   441 greatest_Lower_above ~> greatest_Lower_below
   442 one_zero ~> carrier_one_zero
   443 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   444 
   445 
   446 *** HOL-NSA ***
   447 
   448 * Created new image HOL-NSA, containing theories of nonstandard
   449 analysis which were previously part of HOL-Complex.  Entry point
   450 Hyperreal.thy remains valid, but theories formerly using
   451 Complex_Main.thy should now use new entry point Hypercomplex.thy.
   452 
   453 
   454 *** ZF ***
   455 
   456 * Proof of Zorn's Lemma for partial orders.
   457 
   458 
   459 *** ML ***
   460 
   461 * High-level support for concurrent ML programming, see
   462 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   463 particularly convenient to organize independent functional
   464 computations.  The concept of "synchronized variables" provides a
   465 higher-order interface for components with shared state, avoiding the
   466 delicate details of mutexes and condition variables.  [Poly/ML 5.2.1
   467 or later]
   468 
   469 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   470 to 'a -> thm, while results are always tagged with an authentic oracle
   471 name.  The Isar command 'oracle' is now polymorphic, no argument type
   472 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   473 accordingly.  Note that extra performance may be gained by producing
   474 the cterm carefully, avoiding slow Thm.cterm_of.
   475 
   476 * ML bindings produced via Isar commands are stored within the Isar
   477 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   478 become thread-safe and work with undo as expected (concerning
   479 top-level bindings, not side-effects on global references).
   480 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   481 compiler at runtime; really global bindings need to be given outside a
   482 theory. [Poly/ML 5.2 or later]
   483 
   484 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   485 context. Top-level ML bindings are stored within the proof context in
   486 a purely sequential fashion, disregarding the nested proof structure.
   487 ML bindings introduced by 'ML_prf' are discarded at the end of the
   488 proof.  [Poly/ML 5.2 or later]
   489 
   490 * Generic Toplevel.add_hook interface allows to analyze the result of
   491 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   492 for theorem dependency output of transactions resulting in a new
   493 theory state.
   494 
   495 * Name bindings in higher specification mechanisms (notably
   496 LocalTheory.define, LocalTheory.note, and derived packages) are now
   497 formalized as type Name.binding, replacing old bstring.
   498 INCOMPATIBILITY, need to wrap strings via Name.binding function, see
   499 also Name.name_of.  Packages should pass name bindings given by the
   500 user to underlying specification mechanisms; this enables precise
   501 tracking of source positions, for example.
   502 
   503 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   504 LocalTheory.note etc.) now refer to the *full* internal name, not the
   505 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   506 
   507 * Rules and tactics that read instantiations (read_instantiate,
   508 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   509 context, which is required for parsing and type-checking.  Moreover,
   510 the variables are specified as plain indexnames, not string encodings
   511 thereof.  INCOMPATIBILITY.
   512 
   513 * Disposed old type and term read functions (Sign.read_def_typ,
   514 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   515 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   516 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   517 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   518 resort for legacy applications.
   519 
   520 * Antiquotations: block-structured compilation context indicated by
   521 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   522 
   523   @{let ?pat = term}                      - term abbreviation (HO matching)
   524   @{note name = fact}                     - fact abbreviation
   525   @{thm fact}                             - singleton fact (with attributes)
   526   @{thms fact}                            - general fact (with attributes)
   527   @{lemma prop by method}                 - singleton goal
   528   @{lemma prop by meth1 meth2}            - singleton goal
   529   @{lemma prop1 ... propN by method}      - general goal
   530   @{lemma prop1 ... propN by meth1 meth2} - general goal
   531   @{lemma (open) ...}                     - open derivation
   532 
   533 
   534 *** System ***
   535 
   536 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   537 Poly/ML 5.2.1 or later.
   538 
   539 * The Isabelle "emacs" tool provides a specific interface to invoke
   540 Proof General / Emacs, with more explicit failure if that is not
   541 installed (the old isabelle-interface script silently falls back on
   542 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   543 installation location of the Proof General distribution.
   544 
   545 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   546 the Isabelle process into a JVM/Scala application.  See
   547 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   548 process wrapper has been discontinued.)
   549 
   550 * Status messages (with exact source position information) are
   551 emitted, if proper markup print mode is enabled.  This allows
   552 user-interface components to provide detailed feedback on internal
   553 prover operations.
   554 
   555 * Homegrown Isabelle font with unicode layout, see Isabelle/lib/fonts.
   556 
   557 
   558 
   559 New in Isabelle2008 (June 2008)
   560 -------------------------------
   561 
   562 *** General ***
   563 
   564 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   565 and updated, with formally checked references as hyperlinks.
   566 
   567 * Theory loader: use_thy (and similar operations) no longer set the
   568 implicit ML context, which was occasionally hard to predict and in
   569 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   570 provides a proper context already.
   571 
   572 * Theory loader: old-style ML proof scripts being *attached* to a thy
   573 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   574 'use' within a theory file will do the job.
   575 
   576 * Name space merge now observes canonical order, i.e. the second space
   577 is inserted into the first one, while existing entries in the first
   578 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   579 swap theory imports.
   580 
   581 * Syntax: symbol \<chi> is now considered a letter.  Potential
   582 INCOMPATIBILITY in identifier syntax etc.
   583 
   584 * Outer syntax: string tokens no longer admit escaped white space,
   585 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   586 white space without escapes.
   587 
   588 * Outer syntax: string tokens may contain arbitrary character codes
   589 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   590 "foo_bar".
   591 
   592 
   593 *** Pure ***
   594 
   595 * Context-dependent token translations.  Default setup reverts locally
   596 fixed variables, and adds hilite markup for undeclared frees.
   597 
   598 * Unused theorems can be found using the new command 'unused_thms'.
   599 There are three ways of invoking it:
   600 
   601 (1) unused_thms
   602      Only finds unused theorems in the current theory.
   603 
   604 (2) unused_thms thy_1 ... thy_n -
   605      Finds unused theorems in the current theory and all of its ancestors,
   606      excluding the theories thy_1 ... thy_n and all of their ancestors.
   607 
   608 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   609      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   610      their ancestors, excluding the theories thy_1 ... thy_n and all of
   611      their ancestors.
   612 
   613 In order to increase the readability of the list produced by
   614 unused_thms, theorems that have been created by a particular instance
   615 of a theory command such as 'inductive' or 'function' are considered
   616 to belong to the same "group", meaning that if at least one theorem in
   617 this group is used, the other theorems in the same group are no longer
   618 reported as unused.  Moreover, if all theorems in the group are
   619 unused, only one theorem in the group is displayed.
   620 
   621 Note that proof objects have to be switched on in order for
   622 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   623 usually the case when using Proof General with the default settings).
   624 
   625 * Authentic naming of facts disallows ad-hoc overwriting of previous
   626 theorems within the same name space.  INCOMPATIBILITY, need to remove
   627 duplicate fact bindings, or even accidental fact duplications.  Note
   628 that tools may maintain dynamically scoped facts systematically, using
   629 PureThy.add_thms_dynamic.
   630 
   631 * Command 'hide' now allows to hide from "fact" name space as well.
   632 
   633 * Eliminated destructive theorem database, simpset, claset, and
   634 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   635 update of theories within ML code.
   636 
   637 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   638 INCOMPATIBILITY, object-logics depending on former Pure require
   639 additional setup PureThy.old_appl_syntax_setup; object-logics
   640 depending on former CPure need to refer to Pure.
   641 
   642 * Commands 'use' and 'ML' are now purely functional, operating on
   643 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   644 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   645 INCOMPATIBILITY.
   646 
   647 * Command 'setup': discontinued implicit version with ML reference.
   648 
   649 * Instantiation target allows for simultaneous specification of class
   650 instance operations together with an instantiation proof.
   651 Type-checking phase allows to refer to class operations uniformly.
   652 See src/HOL/Complex/Complex.thy for an Isar example and
   653 src/HOL/Library/Eval.thy for an ML example.
   654 
   655 * Indexing of literal facts: be more serious about including only
   656 facts from the visible specification/proof context, but not the
   657 background context (locale etc.).  Affects `prop` notation and method
   658 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   659 situations.
   660 
   661 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   662 "(open)" option, which used to expose internal bound variables to the
   663 proof text.
   664 
   665 * Isar statements: removed obsolete case "rule_context".
   666 INCOMPATIBILITY, better use explicit fixes/assumes.
   667 
   668 * Locale proofs: default proof step now includes 'unfold_locales';
   669 hence 'proof' without argument may be used to unfold locale
   670 predicates.
   671 
   672 
   673 *** Document preparation ***
   674 
   675 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   676 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   677 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   678 spot); renamed link color from "darkblue" to "linkcolor" (default
   679 value unchanged, can be redefined via \definecolor); no longer sets
   680 "a4paper" option (unnecessary or even intrusive).
   681 
   682 * Antiquotation @{lemma A method} proves proposition A by the given
   683 method (either a method name or a method name plus (optional) method
   684 arguments in parentheses) and prints A just like @{prop A}.
   685 
   686 
   687 *** HOL ***
   688 
   689 * New primrec package.  Specification syntax conforms in style to
   690 definition/function/....  No separate induction rule is provided.  The
   691 "primrec" command distinguishes old-style and new-style specifications
   692 by syntax.  The former primrec package is now named OldPrimrecPackage.
   693 When adjusting theories, beware: constants stemming from new-style
   694 primrec specifications have authentic syntax.
   695 
   696 * Metis prover is now an order of magnitude faster, and also works
   697 with multithreading.
   698 
   699 * Metis: the maximum number of clauses that can be produced from a
   700 theorem is now given by the attribute max_clauses.  Theorems that
   701 exceed this number are ignored, with a warning printed.
   702 
   703 * Sledgehammer no longer produces structured proofs by default. To
   704 enable, declare [[sledgehammer_full = true]].  Attributes
   705 reconstruction_modulus, reconstruction_sorts renamed
   706 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   707 
   708 * Method "induct_scheme" derives user-specified induction rules
   709 from well-founded induction and completeness of patterns. This factors
   710 out some operations that are done internally by the function package
   711 and makes them available separately.  See
   712 src/HOL/ex/Induction_Scheme.thy for examples.
   713 
   714 * More flexible generation of measure functions for termination
   715 proofs: Measure functions can be declared by proving a rule of the
   716 form "is_measure f" and giving it the [measure_function] attribute.
   717 The "is_measure" predicate is logically meaningless (always true), and
   718 just guides the heuristic.  To find suitable measure functions, the
   719 termination prover sets up the goal "is_measure ?f" of the appropriate
   720 type and generates all solutions by prolog-style backwards proof using
   721 the declared rules.
   722 
   723 This setup also deals with rules like 
   724 
   725   "is_measure f ==> is_measure (list_size f)"
   726 
   727 which accommodates nested datatypes that recurse through lists.
   728 Similar rules are predeclared for products and option types.
   729 
   730 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   731 
   732   INCOMPATIBILITIES:
   733 
   734   - Definitions of overloaded constants on sets have to be replaced by
   735     definitions on => and bool.
   736 
   737   - Some definitions of overloaded operators on sets can now be proved
   738     using the definitions of the operators on => and bool.  Therefore,
   739     the following theorems have been renamed:
   740 
   741       subset_def   -> subset_eq
   742       psubset_def  -> psubset_eq
   743       set_diff_def -> set_diff_eq
   744       Compl_def    -> Compl_eq
   745       Sup_set_def  -> Sup_set_eq
   746       Inf_set_def  -> Inf_set_eq
   747       sup_set_def  -> sup_set_eq
   748       inf_set_def  -> inf_set_eq
   749 
   750   - Due to the incompleteness of the HO unification algorithm, some
   751     rules such as subst may require manual instantiation, if some of
   752     the unknowns in the rule is a set.
   753 
   754   - Higher order unification and forward proofs:
   755     The proof pattern
   756 
   757       have "P (S::'a set)" <...>
   758       then have "EX S. P S" ..
   759 
   760     no longer works (due to the incompleteness of the HO unification
   761     algorithm) and must be replaced by the pattern
   762 
   763       have "EX S. P S"
   764       proof
   765         show "P S" <...>
   766       qed
   767 
   768   - Calculational reasoning with subst (or similar rules):
   769     The proof pattern
   770 
   771       have "P (S::'a set)" <...>
   772       also have "S = T" <...>
   773       finally have "P T" .
   774 
   775     no longer works (for similar reasons as the previous example) and
   776     must be replaced by something like
   777 
   778       have "P (S::'a set)" <...>
   779       moreover have "S = T" <...>
   780       ultimately have "P T" by simp
   781 
   782   - Tactics or packages written in ML code:
   783     Code performing pattern matching on types via
   784 
   785       Type ("set", [T]) => ...
   786 
   787     must be rewritten. Moreover, functions like strip_type or
   788     binder_types no longer return the right value when applied to a
   789     type of the form
   790 
   791       T1 => ... => Tn => U => bool
   792 
   793     rather than
   794 
   795       T1 => ... => Tn => U set
   796 
   797 * Merged theories Wellfounded_Recursion, Accessible_Part and
   798 Wellfounded_Relations to theory Wellfounded.
   799 
   800 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   801 
   802 * Class finite no longer treats UNIV as class parameter.  Use class
   803 enum from theory Library/Enum instead to achieve a similar effect.
   804 INCOMPATIBILITY.
   805 
   806 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   807 and "Cons".  INCOMPATIBILITY.
   808 
   809 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   810 Potential INCOMPATIBILITY.
   811 
   812 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   813 injective_fst_snd removed, use split_eta and prod_eqI instead.
   814 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   815 
   816 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   817 the same name in theory Orderings:
   818 
   819   less_trans
   820   less_linear
   821   le_imp_less_or_eq
   822   le_less_trans
   823   less_le_trans
   824   less_not_sym
   825   less_asym
   826 
   827 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   828 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   829 and different variable names.
   830 
   831 * Library/Option_ord.thy: Canonical order on option type.
   832 
   833 * Library/RBT.thy: Red-black trees, an efficient implementation of
   834 finite maps.
   835 
   836 * Library/Countable.thy: Type class for countable types.
   837 
   838 * Theory Int: The representation of numerals has changed.  The infix
   839 operator BIT and the bit datatype with constructors B0 and B1 have
   840 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   841 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   842 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   843 accordingly.
   844 
   845 * Theory Nat: definition of <= and < on natural numbers no longer
   846 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   847 le_def and less_def have disappeared.  Consider lemmas not_less
   848 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   849 
   850 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   851 (whose purpose mainly is for various fold_set functionals) have been
   852 abandoned in favor of the existing algebraic classes
   853 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   854 lower_semilattice (resp. upper_semilattice) and linorder.
   855 INCOMPATIBILITY.
   856 
   857 * Theory Transitive_Closure: induct and cases rules now declare proper
   858 case_names ("base" and "step").  INCOMPATIBILITY.
   859 
   860 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   861 lattices.  The form set-specific version is available as
   862 Inductive.lfp_ordinal_induct_set.
   863 
   864 * Renamed theorems "power.simps" to "power_int.simps".
   865 INCOMPATIBILITY.
   866 
   867 * Class semiring_div provides basic abstract properties of semirings
   868 with division and modulo operations.  Subsumes former class dvd_mod.
   869 
   870 * Merged theories IntDef, Numeral and IntArith into unified theory
   871 Int.  INCOMPATIBILITY.
   872 
   873 * Theory Library/Code_Index: type "index" now represents natural
   874 numbers rather than integers.  INCOMPATIBILITY.
   875 
   876 * New class "uminus" with operation "uminus" (split of from class
   877 "minus" which now only has operation "minus", binary).
   878 INCOMPATIBILITY.
   879 
   880 * Constants "card", "internal_split", "option_map" now with authentic
   881 syntax.  INCOMPATIBILITY.
   882 
   883 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   884 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   885 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   886 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   887 Sup_set_def, le_def, less_def, option_map_def now with object
   888 equality.  INCOMPATIBILITY.
   889 
   890 * Records. Removed K_record, and replaced it by pure lambda term
   891 %x. c. The simplifier setup is now more robust against eta expansion.
   892 INCOMPATIBILITY: in cases explicitly referring to K_record.
   893 
   894 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   895 
   896 * Library/ListVector: new theory of arithmetic vector operations.
   897 
   898 * Library/Order_Relation: new theory of various orderings as sets of
   899 pairs.  Defines preorders, partial orders, linear orders and
   900 well-orders on sets and on types.
   901 
   902 
   903 *** ZF ***
   904 
   905 * Renamed some theories to allow to loading both ZF and HOL in the
   906 same session:
   907 
   908   Datatype  -> Datatype_ZF
   909   Inductive -> Inductive_ZF
   910   Int       -> Int_ZF
   911   IntDiv    -> IntDiv_ZF
   912   Nat       -> Nat_ZF
   913   List      -> List_ZF
   914   Main      -> Main_ZF
   915 
   916 INCOMPATIBILITY: ZF theories that import individual theories below
   917 Main might need to be adapted.  Regular theory Main is still
   918 available, as trivial extension of Main_ZF.
   919 
   920 
   921 *** ML ***
   922 
   923 * ML within Isar: antiquotation @{const name} or @{const
   924 name(typargs)} produces statically-checked Const term.
   925 
   926 * Functor NamedThmsFun: data is available to the user as dynamic fact
   927 (of the same name).  Removed obsolete print command.
   928 
   929 * Removed obsolete "use_legacy_bindings" function.
   930 
   931 * The ``print mode'' is now a thread-local value derived from a global
   932 template (the former print_mode reference), thus access becomes
   933 non-critical.  The global print_mode reference is for session
   934 management only; user-code should use print_mode_value,
   935 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   936 
   937 * Functions system/system_out provide a robust way to invoke external
   938 shell commands, with propagation of interrupts (requires Poly/ML
   939 5.2.1).  Do not use OS.Process.system etc. from the basis library!
   940 
   941 
   942 *** System ***
   943 
   944 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   945 in accordance with Proof General 3.7, which prefers GNU emacs.
   946 
   947 * isatool tty runs Isabelle process with plain tty interaction;
   948 optional line editor may be specified via ISABELLE_LINE_EDITOR
   949 setting, the default settings attempt to locate "ledit" and "rlwrap".
   950 
   951 * isatool browser now works with Cygwin as well, using general
   952 "javapath" function defined in Isabelle process environment.
   953 
   954 * YXML notation provides a simple and efficient alternative to
   955 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   956 isatool yxml as described in the Isabelle system manual.
   957 
   958 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   959 provides general wrapper for managing an Isabelle process in a robust
   960 fashion, with ``cooked'' output from stdin/stderr.
   961 
   962 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   963 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   964 
   965 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   966 way of changing the user's settings is via
   967 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   968 script.
   969 
   970 * Multithreading.max_threads := 0 refers to the number of actual CPU
   971 cores of the underlying machine, which is a good starting point for
   972 optimal performance tuning.  The corresponding usedir option -M allows
   973 "max" as an alias for "0".  WARNING: does not work on certain versions
   974 of Mac OS (with Poly/ML 5.1).
   975 
   976 * isabelle-process: non-ML sessions are run with "nice", to reduce the
   977 adverse effect of Isabelle flooding interactive front-ends (notably
   978 ProofGeneral / XEmacs).
   979 
   980 
   981 
   982 New in Isabelle2007 (November 2007)
   983 -----------------------------------
   984 
   985 *** General ***
   986 
   987 * More uniform information about legacy features, notably a
   988 warning/error of "Legacy feature: ...", depending on the state of the
   989 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
   990 legacy features will disappear eventually.
   991 
   992 * Theory syntax: the header format ``theory A = B + C:'' has been
   993 discontinued in favour of ``theory A imports B C begin''.  Use isatool
   994 fixheaders to convert existing theory files.  INCOMPATIBILITY.
   995 
   996 * Theory syntax: the old non-Isar theory file format has been
   997 discontinued altogether.  Note that ML proof scripts may still be used
   998 with Isar theories; migration is usually quite simple with the ML
   999 function use_legacy_bindings.  INCOMPATIBILITY.
  1000 
  1001 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1002 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1003 quotes.
  1004 
  1005 * Theory loader: be more serious about observing the static theory
  1006 header specifications (including optional directories), but not the
  1007 accidental file locations of previously successful loads.  The strict
  1008 update policy of former update_thy is now already performed by
  1009 use_thy, so the former has been removed; use_thys updates several
  1010 theories simultaneously, just as 'imports' within a theory header
  1011 specification, but without merging the results.  Potential
  1012 INCOMPATIBILITY: may need to refine theory headers and commands
  1013 ROOT.ML which depend on load order.
  1014 
  1015 * Theory loader: optional support for content-based file
  1016 identification, instead of the traditional scheme of full physical
  1017 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1018 (cf. the system manual).  The new scheme allows to work with
  1019 non-finished theories in persistent session images, such that source
  1020 files may be moved later on without requiring reloads.
  1021 
  1022 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1023 file (with the same base name as the theory) are considered a legacy
  1024 feature, which will disappear eventually. Even now, the theory loader
  1025 no longer maintains dependencies on such files.
  1026 
  1027 * Syntax: the scope for resolving ambiguities via type-inference is
  1028 now limited to individual terms, instead of whole simultaneous
  1029 specifications as before. This greatly reduces the complexity of the
  1030 syntax module and improves flexibility by separating parsing and
  1031 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1032 'fixes' etc.) are required in rare situations.
  1033 
  1034 * Syntax: constants introduced by new-style packages ('definition',
  1035 'abbreviation' etc.) are passed through the syntax module in
  1036 ``authentic mode''. This means that associated mixfix annotations
  1037 really stick to such constants, independently of potential name space
  1038 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1039 trees are represented slightly differently, may need to adapt syntax
  1040 translations accordingly. Use CONST marker in 'translations' and
  1041 @{const_syntax} antiquotation in 'parse_translation' etc.
  1042 
  1043 * Legacy goal package: reduced interface to the bare minimum required
  1044 to keep existing proof scripts running.  Most other user-level
  1045 functions are now part of the OldGoals structure, which is *not* open
  1046 by default (consider isatool expandshort before open OldGoals).
  1047 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1048 these tend to cause confusion about the actual goal (!) context being
  1049 used here, which is not necessarily the same as the_context().
  1050 
  1051 * Command 'find_theorems': supports "*" wild-card in "name:"
  1052 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1053 support a specific search form (see ProofGeneral/CHANGES).
  1054 
  1055 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1056 by default, which means that "prems" (and also "fixed variables") are
  1057 suppressed from proof state output.  Note that the ProofGeneral
  1058 settings mechanism allows to change and save options persistently, but
  1059 older versions of Isabelle will fail to start up if a negative prems
  1060 limit is imposed.
  1061 
  1062 * Local theory targets may be specified by non-nested blocks of
  1063 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1064 contain definitions, theorems etc., including any derived mechanism
  1065 that has been implemented on top of these primitives.  This concept
  1066 generalizes the existing ``theorem (in ...)'' towards more versatility
  1067 and scalability.
  1068 
  1069 * Proof General interface: proper undo of final 'end' command;
  1070 discontinued Isabelle/classic mode (ML proof scripts).
  1071 
  1072 
  1073 *** Document preparation ***
  1074 
  1075 * Added antiquotation @{theory name} which prints the given name,
  1076 after checking that it refers to a valid ancestor theory in the
  1077 current context.
  1078 
  1079 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1080 check the given source text as ML type/structure, printing verbatim.
  1081 
  1082 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1083 "c args == rhs" given in the current context.  (Any number of
  1084 arguments may be given on the LHS.)
  1085 
  1086 
  1087 *** Pure ***
  1088 
  1089 * The 'class' package offers a combination of axclass and locale to
  1090 achieve Haskell-like type classes in Isabelle.  Definitions and
  1091 theorems within a class context produce both relative results (with
  1092 implicit parameters according to the locale context), and polymorphic
  1093 constants with qualified polymorphism (according to the class
  1094 context).  Within the body context of a 'class' target, a separate
  1095 syntax layer ("user space type system") takes care of converting
  1096 between global polymorphic consts and internal locale representation.
  1097 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1098 "isatool doc classes" provides a tutorial.
  1099 
  1100 * Generic code generator framework allows to generate executable
  1101 code for ML and Haskell (including Isabelle classes).  A short usage
  1102 sketch:
  1103 
  1104     internal compilation:
  1105         export_code <list of constants (term syntax)> in SML
  1106     writing SML code to a file:
  1107         export_code <list of constants (term syntax)> in SML <filename>
  1108     writing OCaml code to a file:
  1109         export_code <list of constants (term syntax)> in OCaml <filename>
  1110     writing Haskell code to a bunch of files:
  1111         export_code <list of constants (term syntax)> in Haskell <filename>
  1112 
  1113     evaluating closed propositions to True/False using code generation:
  1114         method ``eval''
  1115 
  1116 Reasonable default setup of framework in HOL.
  1117 
  1118 Theorem attributs for selecting and transforming function equations theorems:
  1119 
  1120     [code fun]:        select a theorem as function equation for a specific constant
  1121     [code fun del]:    deselect a theorem as function equation for a specific constant
  1122     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1123     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1124 
  1125 User-defined serializations (target in {SML, OCaml, Haskell}):
  1126 
  1127     code_const <and-list of constants (term syntax)>
  1128       {(target) <and-list of const target syntax>}+
  1129 
  1130     code_type <and-list of type constructors>
  1131       {(target) <and-list of type target syntax>}+
  1132 
  1133     code_instance <and-list of instances>
  1134       {(target)}+
  1135         where instance ::= <type constructor> :: <class>
  1136 
  1137     code_class <and_list of classes>
  1138       {(target) <and-list of class target syntax>}+
  1139         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1140 
  1141 code_instance and code_class only are effective to target Haskell.
  1142 
  1143 For example usage see src/HOL/ex/Codegenerator.thy and
  1144 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1145 generation from Isabelle/HOL theories is available via "isatool doc
  1146 codegen".
  1147 
  1148 * Code generator: consts in 'consts_code' Isar commands are now
  1149 referred to by usual term syntax (including optional type
  1150 annotations).
  1151 
  1152 * Command 'no_translations' removes translation rules from theory
  1153 syntax.
  1154 
  1155 * Overloaded definitions are now actually checked for acyclic
  1156 dependencies.  The overloading scheme is slightly more general than
  1157 that of Haskell98, although Isabelle does not demand an exact
  1158 correspondence to type class and instance declarations.
  1159 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1160 exotic versions of overloading -- at the discretion of the user!
  1161 
  1162 Polymorphic constants are represented via type arguments, i.e. the
  1163 instantiation that matches an instance against the most general
  1164 declaration given in the signature.  For example, with the declaration
  1165 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1166 as c(nat).  Overloading is essentially simultaneous structural
  1167 recursion over such type arguments.  Incomplete specification patterns
  1168 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1169 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1170 Command 'print_theory' outputs the normalized system of recursive
  1171 equations, see section "definitions".
  1172 
  1173 * Configuration options are maintained within the theory or proof
  1174 context (with name and type bool/int/string), providing a very simple
  1175 interface to a poor-man's version of general context data.  Tools may
  1176 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1177 these values using Config.get etc.  Users may change options via an
  1178 associated attribute of the same name.  This form of context
  1179 declaration works particularly well with commands 'declare' or
  1180 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1181 very easy to avoid global references, which would not observe Isar
  1182 toplevel undo/redo and fail to work with multithreading.
  1183 
  1184 Various global ML references of Pure and HOL have been turned into
  1185 configuration options:
  1186 
  1187   Unify.search_bound		unify_search_bound
  1188   Unify.trace_bound		unify_trace_bound
  1189   Unify.trace_simp		unify_trace_simp
  1190   Unify.trace_types		unify_trace_types
  1191   Simplifier.simp_depth_limit	simp_depth_limit
  1192   Blast.depth_limit		blast_depth_limit
  1193   DatatypeProp.dtK		datatype_distinctness_limit
  1194   fast_arith_neq_limit  	fast_arith_neq_limit
  1195   fast_arith_split_limit	fast_arith_split_limit
  1196 
  1197 * Named collections of theorems may be easily installed as context
  1198 data using the functor NamedThmsFun (see also
  1199 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1200 attributes; there is also a toplevel print command.  This facility is
  1201 just a common case of general context data, which is the preferred way
  1202 for anything more complex than just a list of facts in canonical
  1203 order.
  1204 
  1205 * Isar: command 'declaration' augments a local theory by generic
  1206 declaration functions written in ML.  This enables arbitrary content
  1207 being added to the context, depending on a morphism that tells the
  1208 difference of the original declaration context wrt. the application
  1209 context encountered later on.
  1210 
  1211 * Isar: proper interfaces for simplification procedures.  Command
  1212 'simproc_setup' declares named simprocs (with match patterns, and body
  1213 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1214 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1215 
  1216 * Isar: an extra pair of brackets around attribute declarations
  1217 abbreviates a theorem reference involving an internal dummy fact,
  1218 which will be ignored later --- only the effect of the attribute on
  1219 the background context will persist.  This form of in-place
  1220 declarations is particularly useful with commands like 'declare' and
  1221 'using', for example ``have A using [[simproc a]] by simp''.
  1222 
  1223 * Isar: method "assumption" (and implicit closing of subproofs) now
  1224 takes simple non-atomic goal assumptions into account: after applying
  1225 an assumption as a rule the resulting subgoals are solved by atomic
  1226 assumption steps.  This is particularly useful to finish 'obtain'
  1227 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1228 without referring to the original premise "!!x. P x ==> thesis" in the
  1229 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1230 more permissive.
  1231 
  1232 * Isar: implicit use of prems from the Isar proof context is
  1233 considered a legacy feature.  Common applications like ``have A .''
  1234 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1235 referencing facts explicitly here improves readability and
  1236 maintainability of proof texts.
  1237 
  1238 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1239 the obtained context from the course of reasoning!  For example:
  1240 
  1241   assume "EX x y. A x & B y"   -- "any previous fact"
  1242   then guess x and y by clarify
  1243 
  1244 This technique is potentially adventurous, depending on the facts and
  1245 proof tools being involved here.
  1246 
  1247 * Isar: known facts from the proof context may be specified as literal
  1248 propositions, using ASCII back-quote syntax.  This works wherever
  1249 named facts used to be allowed so far, in proof commands, proof
  1250 methods, attributes etc.  Literal facts are retrieved from the context
  1251 according to unification of type and term parameters.  For example,
  1252 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1253 theorems in the current context, then these are valid literal facts:
  1254 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1255 
  1256 There is also a proof method "fact" which does the same composition
  1257 for explicit goal states, e.g. the following proof texts coincide with
  1258 certain special cases of literal facts:
  1259 
  1260   have "A" by fact                 ==  note `A`
  1261   have "A ==> B" by fact           ==  note `A ==> B`
  1262   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1263   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1264 
  1265 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1266 outer syntax.  Thus symbolic identifiers may be used without
  1267 additional white space in declarations like this: ``assume *: A''.
  1268 
  1269 * Isar: 'print_facts' prints all local facts of the current context,
  1270 both named and unnamed ones.
  1271 
  1272 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1273 
  1274   def x == "t" and y == "u"
  1275 
  1276 * Isar: added command 'unfolding', which is structurally similar to
  1277 'using', but affects both the goal state and facts by unfolding given
  1278 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1279 'unfolded' attribute may be replaced by first-class proof text.
  1280 
  1281 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1282 and command 'unfolding' now all support object-level equalities
  1283 (potentially conditional).  The underlying notion of rewrite rule is
  1284 analogous to the 'rule_format' attribute, but *not* that of the
  1285 Simplifier (which is usually more generous).
  1286 
  1287 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1288 premises of a theorem by n. Useful in conjunction with drule.
  1289 
  1290 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1291 method expression within a sandbox consisting of the first N
  1292 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1293 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1294 simplifies all new goals that emerge from applying rule foo to the
  1295 originally first one.
  1296 
  1297 * Isar: schematic goals are no longer restricted to higher-order
  1298 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1299 expected.
  1300 
  1301 * Isar: the conclusion of a long theorem statement is now either
  1302 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1303 (essentially a disjunction of cases with local parameters and
  1304 assumptions).  The latter allows to express general elimination rules
  1305 adequately; in this notation common elimination rules look like this:
  1306 
  1307   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1308     assumes "EX x. P x"
  1309     obtains x where "P x"
  1310 
  1311   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1312     assumes "A & B"
  1313     obtains A and B
  1314 
  1315   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1316     assumes "A | B"
  1317     obtains
  1318       A
  1319     | B
  1320 
  1321 The subsequent classical rules even refer to the formal "thesis"
  1322 explicitly:
  1323 
  1324   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1325     obtains "~ thesis"
  1326 
  1327   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1328     obtains "thesis ==> something"
  1329 
  1330 The actual proof of an 'obtains' statement is analogous to that of the
  1331 Isar proof element 'obtain', only that there may be several cases.
  1332 Optional case names may be specified in parentheses; these will be
  1333 available both in the present proof and as annotations in the
  1334 resulting rule, for later use with the 'cases' method (cf. attribute
  1335 case_names).
  1336 
  1337 * Isar: the assumptions of a long theorem statement are available as
  1338 "assms" fact in the proof context.  This is more appropriate than the
  1339 (historical) "prems", which refers to all assumptions of the current
  1340 context, including those from the target locale, proof body etc.
  1341 
  1342 * Isar: 'print_statement' prints theorems from the current theory or
  1343 proof context in long statement form, according to the syntax of a
  1344 top-level lemma.
  1345 
  1346 * Isar: 'obtain' takes an optional case name for the local context
  1347 introduction rule (default "that").
  1348 
  1349 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1350 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1351 to occur.
  1352 
  1353 * Pure: syntax "CONST name" produces a fully internalized constant
  1354 according to the current context.  This is particularly useful for
  1355 syntax translations that should refer to internal constant
  1356 representations independently of name spaces.
  1357 
  1358 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1359 instead of "FOO ". This allows multiple binder declarations to coexist
  1360 in the same context.  INCOMPATIBILITY.
  1361 
  1362 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1363 primitive that also works in a locale context (both for constants and
  1364 fixed variables). Type declaration and internal syntactic representation
  1365 of given constants retrieved from the context. Likewise, the
  1366 'no_notation' command allows to remove given syntax annotations from the
  1367 current context.
  1368 
  1369 * Isar/locales: new derived specification elements 'axiomatization',
  1370 'definition', 'abbreviation', which support type-inference, admit
  1371 object-level specifications (equality, equivalence).  See also the
  1372 isar-ref manual.  Examples:
  1373 
  1374   axiomatization
  1375     eq  (infix "===" 50) where
  1376     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1377 
  1378   definition "f x y = x + y + 1"
  1379   definition g where "g x = f x x"
  1380 
  1381   abbreviation
  1382     neq  (infix "=!=" 50) where
  1383     "x =!= y == ~ (x === y)"
  1384 
  1385 These specifications may be also used in a locale context.  Then the
  1386 constants being introduced depend on certain fixed parameters, and the
  1387 constant name is qualified by the locale base name.  An internal
  1388 abbreviation takes care for convenient input and output, making the
  1389 parameters implicit and using the original short name.  See also
  1390 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1391 entities from a monomorphic theory.
  1392 
  1393 Presently, abbreviations are only available 'in' a target locale, but
  1394 not inherited by general import expressions.  Also note that
  1395 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1396 'translations' in common applications.  The "no_abbrevs" print mode
  1397 prevents folding of abbreviations in term output.
  1398 
  1399 Concrete syntax is attached to specified constants in internal form,
  1400 independently of name spaces.  The parse tree representation is
  1401 slightly different -- use 'notation' instead of raw 'syntax', and
  1402 'translations' with explicit "CONST" markup to accommodate this.
  1403 
  1404 * Pure/Isar: unified syntax for new-style specification mechanisms
  1405 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1406 full type inference and dummy patterns ("_").  For example:
  1407 
  1408   definition "K x _ = x"
  1409 
  1410   inductive conj for A B
  1411   where "A ==> B ==> conj A B"
  1412 
  1413 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1414 the current context.  Print mode "no_abbrevs" prevents inversion of
  1415 abbreviations on output.
  1416 
  1417 * Isar/locales: improved parameter handling: use of locales "var" and
  1418 "struct" no longer necessary; - parameter renamings are no longer
  1419 required to be injective.  For example, this allows to define
  1420 endomorphisms as locale endom = homom mult mult h.
  1421 
  1422 * Isar/locales: changed the way locales with predicates are defined.
  1423 Instead of accumulating the specification, the imported expression is
  1424 now an interpretation.  INCOMPATIBILITY: different normal form of
  1425 locale expressions.  In particular, in interpretations of locales with
  1426 predicates, goals repesenting already interpreted fragments are not
  1427 removed automatically.  Use methods `intro_locales' and
  1428 `unfold_locales'; see below.
  1429 
  1430 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1431 provide backward reasoning on locales predicates.  The methods are
  1432 aware of interpretations and discharge corresponding goals.
  1433 `intro_locales' is less aggressive then `unfold_locales' and does not
  1434 unfold predicates to assumptions.
  1435 
  1436 * Isar/locales: the order in which locale fragments are accumulated
  1437 has changed.  This enables to override declarations from fragments due
  1438 to interpretations -- for example, unwanted simp rules.
  1439 
  1440 * Isar/locales: interpretation in theories and proof contexts has been
  1441 extended.  One may now specify (and prove) equations, which are
  1442 unfolded in interpreted theorems.  This is useful for replacing
  1443 defined concepts (constants depending on locale parameters) by
  1444 concepts already existing in the target context.  Example:
  1445 
  1446   interpretation partial_order ["op <= :: [int, int] => bool"]
  1447     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1448 
  1449 Typically, the constant `partial_order.less' is created by a
  1450 definition specification element in the context of locale
  1451 partial_order.
  1452 
  1453 * Method "induct": improved internal context management to support
  1454 local fixes and defines on-the-fly. Thus explicit meta-level
  1455 connectives !!  and ==> are rarely required anymore in inductive goals
  1456 (using object-logic connectives for this purpose has been long
  1457 obsolete anyway). Common proof patterns are explained in
  1458 src/HOL/Induct/Common_Patterns.thy, see also
  1459 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1460 examples.
  1461 
  1462 * Method "induct": improved handling of simultaneous goals. Instead of
  1463 introducing object-level conjunction, the statement is now split into
  1464 several conclusions, while the corresponding symbolic cases are nested
  1465 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1466 see src/HOL/Induct/Common_Patterns.thy, for example.
  1467 
  1468 * Method "induct": mutual induction rules are now specified as a list
  1469 of rule sharing the same induction cases. HOL packages usually provide
  1470 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1471 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1472 mutual induction rules differently, i.e. like this:
  1473 
  1474   (induct rule: foo_bar.inducts)
  1475   (induct set: foo bar)
  1476   (induct pred: foo bar)
  1477   (induct type: foo bar)
  1478 
  1479 The ML function ProjectRule.projections turns old-style rules into the
  1480 new format.
  1481 
  1482 * Method "coinduct": dual of induction, see
  1483 src/HOL/Library/Coinductive_List.thy for various examples.
  1484 
  1485 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1486 considered a legacy feature.
  1487 
  1488 * Attribute "symmetric" produces result with standardized schematic
  1489 variables (index 0).  Potential INCOMPATIBILITY.
  1490 
  1491 * Simplifier: by default the simplifier trace only shows top level
  1492 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1493 default. Thus there is less danger of being flooded by the trace. The
  1494 trace indicates where parts have been suppressed.
  1495   
  1496 * Provers/classical: removed obsolete classical version of elim_format
  1497 attribute; classical elim/dest rules are now treated uniformly when
  1498 manipulating the claset.
  1499 
  1500 * Provers/classical: stricter checks to ensure that supplied intro,
  1501 dest and elim rules are well-formed; dest and elim rules must have at
  1502 least one premise.
  1503 
  1504 * Provers/classical: attributes dest/elim/intro take an optional
  1505 weight argument for the rule (just as the Pure versions).  Weights are
  1506 ignored by automated tools, but determine the search order of single
  1507 rule steps.
  1508 
  1509 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1510 where the body does not mention the bound variable.  Note that dummy
  1511 patterns implicitly depend on their context of bounds, which makes
  1512 "{_. _}" match any set comprehension as expected.  Potential
  1513 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1514 constant "_idtdummy" in the binding position.
  1515 
  1516 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1517 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1518 for example "A -> B" => "Pi A (%_. B)".
  1519 
  1520 * Pure: 'class_deps' command visualizes the subclass relation, using
  1521 the graph browser tool.
  1522 
  1523 * Pure: 'print_theory' now suppresses certain internal declarations by
  1524 default; use '!' option for full details.
  1525 
  1526 
  1527 *** HOL ***
  1528 
  1529 * Method "metis" proves goals by applying the Metis general-purpose
  1530 resolution prover (see also http://gilith.com/software/metis/).
  1531 Examples are in the directory MetisExamples.  WARNING: the
  1532 Isabelle/HOL-Metis integration does not yet work properly with
  1533 multi-threading.
  1534   
  1535 * Command 'sledgehammer' invokes external automatic theorem provers as
  1536 background processes.  It generates calls to the "metis" method if
  1537 successful. These can be pasted into the proof.  Users do not have to
  1538 wait for the automatic provers to return.  WARNING: does not really
  1539 work with multi-threading.
  1540 
  1541 * New "auto_quickcheck" feature tests outermost goal statements for
  1542 potential counter-examples.  Controlled by ML references
  1543 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1544 5000 milliseconds).  Fails silently if statements is outside of
  1545 executable fragment, or any other codgenerator problem occurs.
  1546 
  1547 * New constant "undefined" with axiom "undefined x = undefined".
  1548 
  1549 * Added class "HOL.eq", allowing for code generation with polymorphic
  1550 equality.
  1551 
  1552 * Some renaming of class constants due to canonical name prefixing in
  1553 the new 'class' package:
  1554 
  1555     HOL.abs ~> HOL.abs_class.abs
  1556     HOL.divide ~> HOL.divide_class.divide
  1557     0 ~> HOL.zero_class.zero
  1558     1 ~> HOL.one_class.one
  1559     op + ~> HOL.plus_class.plus
  1560     op - ~> HOL.minus_class.minus
  1561     uminus ~> HOL.minus_class.uminus
  1562     op * ~> HOL.times_class.times
  1563     op < ~> HOL.ord_class.less
  1564     op <= > HOL.ord_class.less_eq
  1565     Nat.power ~> Power.power_class.power
  1566     Nat.size ~> Nat.size_class.size
  1567     Numeral.number_of ~> Numeral.number_class.number_of
  1568     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1569     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1570     Orderings.min ~> Orderings.ord_class.min
  1571     Orderings.max ~> Orderings.ord_class.max
  1572     Divides.op div ~> Divides.div_class.div
  1573     Divides.op mod ~> Divides.div_class.mod
  1574     Divides.op dvd ~> Divides.div_class.dvd
  1575 
  1576 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1577 
  1578 a) User-defined constants using any of the names "plus", "minus",
  1579 "times", "less" or "less_eq". The standard syntax translations for
  1580 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1581 names.
  1582 
  1583 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1584 INCOMPATIBILITY: use more specific names.
  1585 
  1586 c) Permutative equations (e.g. "a + b = b + a")
  1587 Since the change of names also changes the order of terms, permutative
  1588 rewrite rules may get applied in a different order. Experience shows
  1589 that this is rarely the case (only two adaptions in the whole Isabelle
  1590 distribution).  INCOMPATIBILITY: rewrite proofs
  1591 
  1592 d) ML code directly refering to constant names
  1593 This in general only affects hand-written proof tactics, simprocs and
  1594 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1595 Consider using @{const_name} antiquotation.
  1596 
  1597 * New class "default" with associated constant "default".
  1598 
  1599 * Function "sgn" is now overloaded and available on int, real, complex
  1600 (and other numeric types), using class "sgn".  Two possible defs of
  1601 sgn are given as equational assumptions in the classes sgn_if and
  1602 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1603 INCOMPATIBILITY.
  1604 
  1605 * Locale "partial_order" now unified with class "order" (cf. theory
  1606 Orderings), added parameter "less".  INCOMPATIBILITY.
  1607 
  1608 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1609 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1610 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1611 
  1612 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1613 changed order of proof goals in instance proofs.
  1614 
  1615 * The transitivity reasoner for partial and linear orders is set up
  1616 for classes "order" and "linorder".  Instances of the reasoner are available
  1617 in all contexts importing or interpreting the corresponding locales.
  1618 Method "order" invokes the reasoner separately; the reasoner
  1619 is also integrated with the Simplifier as a solver.  Diagnostic
  1620 command 'print_orders' shows the available instances of the reasoner
  1621 in the current context.
  1622 
  1623 * Localized monotonicity predicate in theory "Orderings"; integrated
  1624 lemmas max_of_mono and min_of_mono with this predicate.
  1625 INCOMPATIBILITY.
  1626 
  1627 * Formulation of theorem "dense" changed slightly due to integration
  1628 with new class dense_linear_order.
  1629 
  1630 * Uniform lattice theory development in HOL.
  1631 
  1632     constants "meet" and "join" now named "inf" and "sup"
  1633     constant "Meet" now named "Inf"
  1634 
  1635     classes "meet_semilorder" and "join_semilorder" now named
  1636       "lower_semilattice" and "upper_semilattice"
  1637     class "lorder" now named "lattice"
  1638     class "comp_lat" now named "complete_lattice"
  1639 
  1640     Instantiation of lattice classes allows explicit definitions
  1641     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1642 
  1643   INCOMPATIBILITY.  Theorem renames:
  1644 
  1645     meet_left_le            ~> inf_le1
  1646     meet_right_le           ~> inf_le2
  1647     join_left_le            ~> sup_ge1
  1648     join_right_le           ~> sup_ge2
  1649     meet_join_le            ~> inf_sup_ord
  1650     le_meetI                ~> le_infI
  1651     join_leI                ~> le_supI
  1652     le_meet                 ~> le_inf_iff
  1653     le_join                 ~> ge_sup_conv
  1654     meet_idempotent         ~> inf_idem
  1655     join_idempotent         ~> sup_idem
  1656     meet_comm               ~> inf_commute
  1657     join_comm               ~> sup_commute
  1658     meet_leI1               ~> le_infI1
  1659     meet_leI2               ~> le_infI2
  1660     le_joinI1               ~> le_supI1
  1661     le_joinI2               ~> le_supI2
  1662     meet_assoc              ~> inf_assoc
  1663     join_assoc              ~> sup_assoc
  1664     meet_left_comm          ~> inf_left_commute
  1665     meet_left_idempotent    ~> inf_left_idem
  1666     join_left_comm          ~> sup_left_commute
  1667     join_left_idempotent    ~> sup_left_idem
  1668     meet_aci                ~> inf_aci
  1669     join_aci                ~> sup_aci
  1670     le_def_meet             ~> le_iff_inf
  1671     le_def_join             ~> le_iff_sup
  1672     join_absorp2            ~> sup_absorb2
  1673     join_absorp1            ~> sup_absorb1
  1674     meet_absorp1            ~> inf_absorb1
  1675     meet_absorp2            ~> inf_absorb2
  1676     meet_join_absorp        ~> inf_sup_absorb
  1677     join_meet_absorp        ~> sup_inf_absorb
  1678     distrib_join_le         ~> distrib_sup_le
  1679     distrib_meet_le         ~> distrib_inf_le
  1680 
  1681     add_meet_distrib_left   ~> add_inf_distrib_left
  1682     add_join_distrib_left   ~> add_sup_distrib_left
  1683     is_join_neg_meet        ~> is_join_neg_inf
  1684     is_meet_neg_join        ~> is_meet_neg_sup
  1685     add_meet_distrib_right  ~> add_inf_distrib_right
  1686     add_join_distrib_right  ~> add_sup_distrib_right
  1687     add_meet_join_distribs  ~> add_sup_inf_distribs
  1688     join_eq_neg_meet        ~> sup_eq_neg_inf
  1689     meet_eq_neg_join        ~> inf_eq_neg_sup
  1690     add_eq_meet_join        ~> add_eq_inf_sup
  1691     meet_0_imp_0            ~> inf_0_imp_0
  1692     join_0_imp_0            ~> sup_0_imp_0
  1693     meet_0_eq_0             ~> inf_0_eq_0
  1694     join_0_eq_0             ~> sup_0_eq_0
  1695     neg_meet_eq_join        ~> neg_inf_eq_sup
  1696     neg_join_eq_meet        ~> neg_sup_eq_inf
  1697     join_eq_if              ~> sup_eq_if
  1698 
  1699     mono_meet               ~> mono_inf
  1700     mono_join               ~> mono_sup
  1701     meet_bool_eq            ~> inf_bool_eq
  1702     join_bool_eq            ~> sup_bool_eq
  1703     meet_fun_eq             ~> inf_fun_eq
  1704     join_fun_eq             ~> sup_fun_eq
  1705     meet_set_eq             ~> inf_set_eq
  1706     join_set_eq             ~> sup_set_eq
  1707     meet1_iff               ~> inf1_iff
  1708     meet2_iff               ~> inf2_iff
  1709     meet1I                  ~> inf1I
  1710     meet2I                  ~> inf2I
  1711     meet1D1                 ~> inf1D1
  1712     meet2D1                 ~> inf2D1
  1713     meet1D2                 ~> inf1D2
  1714     meet2D2                 ~> inf2D2
  1715     meet1E                  ~> inf1E
  1716     meet2E                  ~> inf2E
  1717     join1_iff               ~> sup1_iff
  1718     join2_iff               ~> sup2_iff
  1719     join1I1                 ~> sup1I1
  1720     join2I1                 ~> sup2I1
  1721     join1I1                 ~> sup1I1
  1722     join2I2                 ~> sup1I2
  1723     join1CI                 ~> sup1CI
  1724     join2CI                 ~> sup2CI
  1725     join1E                  ~> sup1E
  1726     join2E                  ~> sup2E
  1727 
  1728     is_meet_Meet            ~> is_meet_Inf
  1729     Meet_bool_def           ~> Inf_bool_def
  1730     Meet_fun_def            ~> Inf_fun_def
  1731     Meet_greatest           ~> Inf_greatest
  1732     Meet_lower              ~> Inf_lower
  1733     Meet_set_def            ~> Inf_set_def
  1734 
  1735     Sup_def                 ~> Sup_Inf
  1736     Sup_bool_eq             ~> Sup_bool_def
  1737     Sup_fun_eq              ~> Sup_fun_def
  1738     Sup_set_eq              ~> Sup_set_def
  1739 
  1740     listsp_meetI            ~> listsp_infI
  1741     listsp_meet_eq          ~> listsp_inf_eq
  1742 
  1743     meet_min                ~> inf_min
  1744     join_max                ~> sup_max
  1745 
  1746 * Added syntactic class "size"; overloaded constant "size" now has
  1747 type "'a::size ==> bool"
  1748 
  1749 * Internal reorganisation of `size' of datatypes: size theorems
  1750 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1751 simplification rules by default!); theorems "prod.size" now named
  1752 "*.size".
  1753 
  1754 * Class "div" now inherits from class "times" rather than "type".
  1755 INCOMPATIBILITY.
  1756 
  1757 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1758 Linorder etc.  have disappeared; operations defined in terms of
  1759 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1760 
  1761 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1762 
  1763 * HOL-Word: New extensive library and type for generic, fixed size
  1764 machine words, with arithemtic, bit-wise, shifting and rotating
  1765 operations, reflection into int, nat, and bool lists, automation for
  1766 linear arithmetic (by automatic reflection into nat or int), including
  1767 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1768 arithmetic type classes, supporting automatic simplification of
  1769 numerals on all operations.
  1770 
  1771 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1772 
  1773 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1774 
  1775 * Code generator library theories:
  1776   - Code_Integer represents HOL integers by big integer literals in target
  1777     languages.
  1778   - Code_Char represents HOL characters by character literals in target
  1779     languages.
  1780   - Code_Char_chr like Code_Char, but also offers treatment of character
  1781     codes; includes Code_Integer.
  1782   - Executable_Set allows to generate code for finite sets using lists.
  1783   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1784     denominator).
  1785   - Executable_Real implements a subset of real numbers, namly those
  1786     representable by rational numbers.
  1787   - Efficient_Nat implements natural numbers by integers, which in general will
  1788     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1789     includes Code_Integer.
  1790   - Code_Index provides an additional datatype index which is mapped to
  1791     target-language built-in integers.
  1792   - Code_Message provides an additional datatype message_string which is isomorphic to
  1793     strings; messages are mapped to target-language strings.
  1794 
  1795 * New package for inductive predicates
  1796 
  1797   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1798 
  1799     inductive
  1800       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1801       for z_1 :: U_1 and ... and z_n :: U_m
  1802     where
  1803       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1804     | ...
  1805 
  1806   with full support for type-inference, rather than
  1807 
  1808     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1809 
  1810     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1811     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1812 
  1813     inductive "s z_1 ... z_m"
  1814     intros
  1815       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1816       ...
  1817 
  1818   For backward compatibility, there is a wrapper allowing inductive
  1819   sets to be defined with the new package via
  1820 
  1821     inductive_set
  1822       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1823       for z_1 :: U_1 and ... and z_n :: U_m
  1824     where
  1825       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1826     | ...
  1827 
  1828   or
  1829 
  1830     inductive_set
  1831       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1832       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1833       for z_1 :: U_1 and ... and z_n :: U_m
  1834     where
  1835       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1836     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1837     | ...
  1838 
  1839   if the additional syntax "p ..." is required.
  1840 
  1841   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1842   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1843 
  1844   INCOMPATIBILITIES:
  1845 
  1846   - Since declaration and definition of inductive sets or predicates
  1847     is no longer separated, abbreviations involving the newly
  1848     introduced sets or predicates must be specified together with the
  1849     introduction rules after the 'where' keyword (see above), rather
  1850     than before the actual inductive definition.
  1851 
  1852   - The variables in induction and elimination rules are now
  1853     quantified in the order of their occurrence in the introduction
  1854     rules, rather than in alphabetical order. Since this may break
  1855     some proofs, these proofs either have to be repaired, e.g. by
  1856     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1857     statements of the form
  1858 
  1859       case (rule_i a_i_1 ... a_i_{k_i})
  1860 
  1861     or the old order of quantification has to be restored by explicitly adding
  1862     meta-level quantifiers in the introduction rules, i.e.
  1863 
  1864       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1865 
  1866   - The format of the elimination rules is now
  1867 
  1868       p z_1 ... z_m x_1 ... x_n ==>
  1869         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1870         ==> ... ==> P
  1871 
  1872     for predicates and
  1873 
  1874       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1875         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1876         ==> ... ==> P
  1877 
  1878     for sets rather than
  1879 
  1880       x : s z_1 ... z_m ==>
  1881         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1882         ==> ... ==> P
  1883 
  1884     This may require terms in goals to be expanded to n-tuples
  1885     (e.g. using case_tac or simplification with the split_paired_all
  1886     rule) before the above elimination rule is applicable.
  1887 
  1888   - The elimination or case analysis rules for (mutually) inductive
  1889     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1890     list of rules "p_1_..._p_k.elims" is no longer available.
  1891 
  1892 * New package "function"/"fun" for general recursive functions,
  1893 supporting mutual and nested recursion, definitions in local contexts,
  1894 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1895 for small examples, and the separate tutorial on the function
  1896 package. The old recdef "package" is still available as before, but
  1897 users are encouraged to use the new package.
  1898 
  1899 * Method "lexicographic_order" automatically synthesizes termination
  1900 relations as lexicographic combinations of size measures. 
  1901 
  1902 * Case-expressions allow arbitrary constructor-patterns (including
  1903 "_") and take their order into account, like in functional
  1904 programming.  Internally, this is translated into nested
  1905 case-expressions; missing cases are added and mapped to the predefined
  1906 constant "undefined". In complicated cases printing may no longer show
  1907 the original input but the internal form. Lambda-abstractions allow
  1908 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1909 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1910 variable.
  1911 
  1912 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1913 is an abbreviation for "of_nat :: nat => int". The simplification
  1914 rules for "of_nat" have been changed to work like "int" did
  1915 previously.  Potential INCOMPATIBILITY:
  1916   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1917   - of_nat_diff and of_nat_mult are no longer default simp rules
  1918 
  1919 * Method "algebra" solves polynomial equations over (semi)rings using
  1920 Groebner bases. The (semi)ring structure is defined by locales and the
  1921 tool setup depends on that generic context. Installing the method for
  1922 a specific type involves instantiating the locale and possibly adding
  1923 declarations for computation on the coefficients.  The method is
  1924 already instantiated for natural numbers and for the axiomatic class
  1925 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1926 CALCULEMUS 2007 for the general principles underlying this
  1927 architecture of context-aware proof-tools.
  1928 
  1929 * Method "ferrack" implements quantifier elimination over
  1930 special-purpose dense linear orders using locales (analogous to
  1931 "algebra"). The method is already installed for class
  1932 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1933 rat, etc.
  1934 
  1935 * Former constant "List.op @" now named "List.append".  Use ML
  1936 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1937 circumvent possible incompatibilities when working on ML level.
  1938 
  1939 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1940 
  1941 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1942 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1943 
  1944 * New syntax for Haskell-like list comprehension (input only), eg.
  1945 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1946 
  1947 * The special syntax for function "filter" has changed from [x :
  1948 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1949 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1950 
  1951 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1952 defined on nat only, as an abbreviation for [a..<Suc b]
  1953 INCOMPATIBILITY.
  1954 
  1955 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1956 
  1957 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1958 
  1959 * New lemma collection field_simps (an extension of ring_simps) for
  1960 manipulating (in)equations involving division. Multiplies with all
  1961 denominators that can be proved to be non-zero (in equations) or
  1962 positive/negative (in inequations).
  1963 
  1964 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1965 have been improved and renamed to ring_simps, group_simps and
  1966 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1967 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1968 
  1969 * Theory Library/Commutative_Ring: switched from recdef to function
  1970 package; constants add, mul, pow now curried.  Infix syntax for
  1971 algebraic operations.
  1972 
  1973 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1974 INCOMPATIBILITY.
  1975 
  1976 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1977 INCOMPATIBILITY.
  1978 
  1979 * HOL/records: generalised field-update to take a function on the
  1980 field rather than the new value: r(|A := x|) is translated to A_update
  1981 (K x) r The K-combinator that is internally used is called K_record.
  1982 INCOMPATIBILITY: Usage of the plain update functions has to be
  1983 adapted.
  1984  
  1985 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1986 * x = 0, which are required for a semiring.  Richer structures do not
  1987 inherit from semiring_0 anymore, because this property is a theorem
  1988 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1989 there is more to prove, but this is mostly trivial.
  1990 
  1991 * Class "recpower" is generalized to arbitrary monoids, not just
  1992 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1993 commutativity or semiring properties additionally.
  1994 
  1995 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1996 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1997 better use 'abbreviation'.
  1998 
  1999 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2000 
  2001 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2002 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2003 significant changes for setting up numeral syntax for types:
  2004   - New constants Numeral.pred and Numeral.succ instead
  2005       of former Numeral.bin_pred and Numeral.bin_succ.
  2006   - Use integer operations instead of bin_add, bin_mult and so on.
  2007   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2008   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2009 
  2010 See src/HOL/Integ/IntArith.thy for an example setup.
  2011 
  2012 * Command 'normal_form' computes the normal form of a term that may
  2013 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2014 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2015 heavy-duty computations because the functions are compiled to ML
  2016 first.  Correspondingly, a method "normalization" is provided.  See
  2017 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2018 
  2019 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2020 25 like -->); output depends on the "iff" print_mode, the default is
  2021 "A = B" (with priority 50).
  2022 
  2023 * Relations less (<) and less_eq (<=) are also available on type bool.
  2024 Modified syntax to disallow nesting without explicit parentheses,
  2025 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2026 INCOMPATIBILITY.
  2027 
  2028 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2029 
  2030 * Relation composition operator "op O" now has precedence 75 and binds
  2031 stronger than union and intersection. INCOMPATIBILITY.
  2032 
  2033 * The old set interval syntax "{m..n(}" (and relatives) has been
  2034 removed.  Use "{m..<n}" (and relatives) instead.
  2035 
  2036 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2037 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2038 ``declare [[simproc del: neq]]''.
  2039 
  2040 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2041 True/False.
  2042 
  2043 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2044 
  2045 * Theorem setsum_mult renamed to setsum_right_distrib.
  2046 
  2047 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2048 ``rule'' method.
  2049 
  2050 * Reimplemented methods "sat" and "satx", with several improvements:
  2051 goals no longer need to be stated as "<prems> ==> False", equivalences
  2052 (i.e. "=" on type bool) are handled, variable names of the form
  2053 "lit_<n>" are no longer reserved, significant speedup.
  2054 
  2055 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2056 zChaff is still supported as well.
  2057 
  2058 * 'inductive' and 'datatype': provide projections of mutual rules,
  2059 bundled as foo_bar.inducts;
  2060 
  2061 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2062 Library.
  2063 
  2064 * Library: moved theory Accessible_Part to main HOL.
  2065 
  2066 * Library: added theory Coinductive_List of potentially infinite lists
  2067 as greatest fixed-point.
  2068 
  2069 * Library: added theory AssocList which implements (finite) maps as
  2070 association lists.
  2071 
  2072 * Method "evaluation" solves goals (i.e. a boolean expression)
  2073 efficiently by compiling it to ML.  The goal is "proved" (via an
  2074 oracle) if it evaluates to True.
  2075 
  2076 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2077 also when invoked by the simplifier.  This results in the Simplifier
  2078 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2079 Configuration option fast_arith_split_limit=0 recovers the old
  2080 behavior.
  2081 
  2082 * Support for hex (0x20) and binary (0b1001) numerals.
  2083 
  2084 * New method: reify eqs (t), where eqs are equations for an
  2085 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2086 parameter, computes a term s::'b and a list xs::'a list and proves the
  2087 theorem I xs s = t. This is also known as reification or quoting. The
  2088 resulting theorem is applied to the subgoal to substitute t with I xs
  2089 s.  If t is omitted, the subgoal itself is reified.
  2090 
  2091 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2092 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2093 where f is supposed to be a computable function (in the sense of code
  2094 generattion). The method uses reify to compute s and xs as above then
  2095 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2096 r and finally gets the theorem t = r, which is again applied to the
  2097 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2098 
  2099 * Reflection: Automatic reification now handels binding, an example is
  2100 available in src/HOL/ex/ReflectionEx.thy
  2101 
  2102 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2103 command 'statespace' that is similar to 'record', but introduces an
  2104 abstract specification based on the locale infrastructure instead of
  2105 HOL types.  This leads to extra flexibility in composing state spaces,
  2106 in particular multiple inheritance and renaming of components.
  2107 
  2108 
  2109 *** HOL-Complex ***
  2110 
  2111 * Hyperreal: Functions root and sqrt are now defined on negative real
  2112 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2113 Nonnegativity side conditions have been removed from many lemmas, so
  2114 that more subgoals may now be solved by simplification; potential
  2115 INCOMPATIBILITY.
  2116 
  2117 * Real: new type classes formalize real normed vector spaces and
  2118 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2119 and norm :: 'a => real.
  2120 
  2121 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2122 reals into other types. The overloaded constant Reals :: 'a set is now
  2123 defined as range of_real; potential INCOMPATIBILITY.
  2124 
  2125 * Real: proper support for ML code generation, including 'quickcheck'.
  2126 Reals are implemented as arbitrary precision rationals.
  2127 
  2128 * Hyperreal: Several constants that previously worked only for the
  2129 reals have been generalized, so they now work over arbitrary vector
  2130 spaces. Type annotations may need to be added in some cases; potential
  2131 INCOMPATIBILITY.
  2132 
  2133   Infinitesimal  :: ('a::real_normed_vector) star set
  2134   HFinite        :: ('a::real_normed_vector) star set
  2135   HInfinite      :: ('a::real_normed_vector) star set
  2136   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2137   monad          :: ('a::real_normed_vector) star => 'a star set
  2138   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2139   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2140   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2141   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2142   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2143   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2144   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2145   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2146   sgn            :: 'a::real_normed_vector => 'a
  2147   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2148 
  2149 * Complex: Some complex-specific constants are now abbreviations for
  2150 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2151 hnorm.  Other constants have been entirely removed in favor of the
  2152 polymorphic versions (INCOMPATIBILITY):
  2153 
  2154   approx        <-- capprox
  2155   HFinite       <-- CFinite
  2156   HInfinite     <-- CInfinite
  2157   Infinitesimal <-- CInfinitesimal
  2158   monad         <-- cmonad
  2159   galaxy        <-- cgalaxy
  2160   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2161   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2162   (ns)deriv     <-- (ns)cderiv
  2163 
  2164 
  2165 *** HOL-Algebra ***
  2166 
  2167 * Formalisation of ideals and the quotient construction over rings.
  2168 
  2169 * Order and lattice theory no longer based on records.
  2170 INCOMPATIBILITY.
  2171 
  2172 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2173 greatest_closed.  INCOMPATIBILITY.
  2174 
  2175 * Method algebra is now set up via an attribute.  For examples see
  2176 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2177 of algebraic structures.
  2178 
  2179 * Renamed theory CRing to Ring.
  2180 
  2181 
  2182 *** HOL-Nominal ***
  2183 
  2184 * Substantial, yet incomplete support for nominal datatypes (binding
  2185 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2186 src/HOL/Nominal/Examples.  Prospective users should consult
  2187 http://isabelle.in.tum.de/nominal/
  2188 
  2189 
  2190 *** ML ***
  2191 
  2192 * ML basics: just one true type int, which coincides with IntInf.int
  2193 (even on SML/NJ).
  2194 
  2195 * ML within Isar: antiquotations allow to embed statically-checked
  2196 formal entities in the source, referring to the context available at
  2197 compile-time.  For example:
  2198 
  2199 ML {* @{sort "{zero,one}"} *}
  2200 ML {* @{typ "'a => 'b"} *}
  2201 ML {* @{term "%x. x"} *}
  2202 ML {* @{prop "x == y"} *}
  2203 ML {* @{ctyp "'a => 'b"} *}
  2204 ML {* @{cterm "%x. x"} *}
  2205 ML {* @{cprop "x == y"} *}
  2206 ML {* @{thm asm_rl} *}
  2207 ML {* @{thms asm_rl} *}
  2208 ML {* @{type_name c} *}
  2209 ML {* @{type_syntax c} *}
  2210 ML {* @{const_name c} *}
  2211 ML {* @{const_syntax c} *}
  2212 ML {* @{context} *}
  2213 ML {* @{theory} *}
  2214 ML {* @{theory Pure} *}
  2215 ML {* @{theory_ref} *}
  2216 ML {* @{theory_ref Pure} *}
  2217 ML {* @{simpset} *}
  2218 ML {* @{claset} *}
  2219 ML {* @{clasimpset} *}
  2220 
  2221 The same works for sources being ``used'' within an Isar context.
  2222 
  2223 * ML in Isar: improved error reporting; extra verbosity with
  2224 ML_Context.trace enabled.
  2225 
  2226 * Pure/General/table.ML: the join operations now works via exceptions
  2227 DUP/SAME instead of type option. This is simpler in simple cases, and
  2228 admits slightly more efficient complex applications.
  2229 
  2230 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2231 use Context.generic instead of just theory.
  2232 
  2233 * Pure: datatype Context.generic joins theory/Proof.context and
  2234 provides some facilities for code that works in either kind of
  2235 context, notably GenericDataFun for uniform theory and proof data.
  2236 
  2237 * Pure: simplified internal attribute type, which is now always
  2238 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2239 local (Proof.context) attributes have been discontinued, while
  2240 minimizing code duplication. Thm.rule_attribute and
  2241 Thm.declaration_attribute build canonical attributes; see also structure
  2242 Context for further operations on Context.generic, notably
  2243 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2244 declarations and definitions.
  2245 
  2246 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2247 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2248 init only required for impure data. INCOMPATIBILITY: empty really need
  2249 to be empty (no dependencies on theory content!)
  2250 
  2251 * Pure/kernel: consts certification ignores sort constraints given in
  2252 signature declarations. (This information is not relevant to the
  2253 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2254 potential INCOMPATIBILITY.
  2255 
  2256 * Pure: axiomatic type classes are now purely definitional, with
  2257 explicit proofs of class axioms and super class relations performed
  2258 internally. See Pure/axclass.ML for the main internal interfaces --
  2259 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2260 AxClass.axiomatize_class/classrel/arity supersede
  2261 Sign.add_classes/classrel/arities.
  2262 
  2263 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2264 global/local versions on theory vs. Proof.context have been
  2265 discontinued; Attrib.syntax and Method.syntax have been adapted
  2266 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2267 attributes, methods, etc.
  2268 
  2269 * Pure: several functions of signature "... -> theory -> theory * ..."
  2270 have been reoriented to "... -> theory -> ... * theory" in order to
  2271 allow natural usage in combination with the ||>, ||>>, |-> and
  2272 fold_map combinators.
  2273 
  2274 * Pure: official theorem names (closed derivations) and additional
  2275 comments (tags) are now strictly separate.  Name hints -- which are
  2276 maintained as tags -- may be attached any time without affecting the
  2277 derivation.
  2278 
  2279 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2280 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2281 achieve the old behaviour.
  2282 
  2283 * Pure: the "Goal" constant is now called "prop", supporting a
  2284 slightly more general idea of ``protecting'' meta-level rule
  2285 statements.
  2286 
  2287 * Pure: Logic.(un)varify only works in a global context, which is now
  2288 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2289 Logic.legacy_(un)varify as temporary workaround.
  2290 
  2291 * Pure: structure Name provides scalable operations for generating
  2292 internal variable names, notably Name.variants etc.  This replaces
  2293 some popular functions from term.ML:
  2294 
  2295   Term.variant		->  Name.variant
  2296   Term.variantlist	->  Name.variant_list
  2297   Term.invent_names	->  Name.invent_list
  2298 
  2299 Note that low-level renaming rarely occurs in new code -- operations
  2300 from structure Variable are used instead (see below).
  2301 
  2302 * Pure: structure Variable provides fundamental operations for proper
  2303 treatment of fixed/schematic variables in a context.  For example,
  2304 Variable.import introduces fixes for schematics of given facts and
  2305 Variable.export reverses the effect (up to renaming) -- this replaces
  2306 various freeze_thaw operations.
  2307 
  2308 * Pure: structure Goal provides simple interfaces for
  2309 init/conclude/finish and tactical prove operations (replacing former
  2310 Tactic.prove).  Goal.prove is the canonical way to prove results
  2311 within a given context; Goal.prove_global is a degraded version for
  2312 theory level goals, including a global Drule.standard.  Note that
  2313 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2314 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2315 in a locale context).
  2316 
  2317 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2318 and type checking (Syntax.check_term etc.), with common combinations
  2319 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2320 which are considered legacy and await removal.
  2321 
  2322 * Pure/Syntax: generic interfaces for type unchecking
  2323 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2324 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2325 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2326 available for convenience, but refer to the very same operations using
  2327 a mere theory instead of a full context.
  2328 
  2329 * Isar: simplified treatment of user-level errors, using exception
  2330 ERROR of string uniformly.  Function error now merely raises ERROR,
  2331 without any side effect on output channels.  The Isar toplevel takes
  2332 care of proper display of ERROR exceptions.  ML code may use plain
  2333 handle/can/try; cat_error may be used to concatenate errors like this:
  2334 
  2335   ... handle ERROR msg => cat_error msg "..."
  2336 
  2337 Toplevel ML code (run directly or through the Isar toplevel) may be
  2338 embedded into the Isar toplevel with exception display/debug like
  2339 this:
  2340 
  2341   Isar.toplevel (fn () => ...)
  2342 
  2343 INCOMPATIBILITY, removed special transform_error facilities, removed
  2344 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2345 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2346 -- use plain ERROR instead.
  2347 
  2348 * Isar: theory setup now has type (theory -> theory), instead of a
  2349 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2350 
  2351 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2352 ProofContext.debug/verbose flags.
  2353 
  2354 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2355 theory before entering a proof state.  Transactions now always see a
  2356 quasi-functional intermediate checkpoint, both in interactive and
  2357 batch mode.
  2358 
  2359 * Isar: simplified interfaces for outer syntax.  Renamed
  2360 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2361 OuterSyntax.add_parsers -- this functionality is now included in
  2362 OuterSyntax.command etc.  INCOMPATIBILITY.
  2363 
  2364 * Simplifier: the simpset of a running simplification process now
  2365 contains a proof context (cf. Simplifier.the_context), which is the
  2366 very context that the initial simpset has been retrieved from (by
  2367 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2368 (solver, looper etc.) may depend on arbitrary proof data.
  2369 
  2370 * Simplifier.inherit_context inherits the proof context (plus the
  2371 local bounds) of the current simplification process; any simproc
  2372 etc. that calls the Simplifier recursively should do this!  Removed
  2373 former Simplifier.inherit_bounds, which is already included here --
  2374 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2375 specify an explicit context using Simplifier.context/theory_context.
  2376 
  2377 * Simplifier/Classical Reasoner: more abstract interfaces
  2378 change_simpset/claset for modifying the simpset/claset reference of a
  2379 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2380 INCOMPATIBILITY.
  2381 
  2382 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2383 "Trueprop" etc.
  2384 
  2385 
  2386 *** System ***
  2387 
  2388 * settings: the default heap location within ISABELLE_HOME_USER now
  2389 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2390 Isabelle installations.
  2391 
  2392 * isabelle-process: option -S (secure mode) disables some critical
  2393 operations, notably runtime compilation and evaluation of ML source
  2394 code.
  2395 
  2396 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2397 
  2398 * Support for parallel execution, using native multicore support of
  2399 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2400 independent theories, according to the given theory header
  2401 specifications. The maximum number of worker threads is specified via
  2402 usedir option -M or the "max-threads" setting in Proof General. A
  2403 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2404 to 6 on a 8-core machine.  User-code needs to observe certain
  2405 guidelines for thread-safe programming, see appendix A in the Isar
  2406 Implementation manual.
  2407 
  2408 
  2409 
  2410 New in Isabelle2005 (October 2005)
  2411 ----------------------------------
  2412 
  2413 *** General ***
  2414 
  2415 * Theory headers: the new header syntax for Isar theories is
  2416 
  2417   theory <name>
  2418   imports <theory1> ... <theoryN>
  2419   uses <file1> ... <fileM>
  2420   begin
  2421 
  2422 where the 'uses' part is optional.  The previous syntax
  2423 
  2424   theory <name> = <theory1> + ... + <theoryN>:
  2425 
  2426 will disappear in the next release.  Use isatool fixheaders to convert
  2427 existing theory files.  Note that there is no change in ancient
  2428 non-Isar theories now, but these will disappear soon.
  2429 
  2430 * Theory loader: parent theories can now also be referred to via
  2431 relative and absolute paths.
  2432 
  2433 * Command 'find_theorems' searches for a list of criteria instead of a
  2434 list of constants. Known criteria are: intro, elim, dest, name:string,
  2435 simp:term, and any term. Criteria can be preceded by '-' to select
  2436 theorems that do not match. Intro, elim, dest select theorems that
  2437 match the current goal, name:s selects theorems whose fully qualified
  2438 name contain s, and simp:term selects all simplification rules whose
  2439 lhs match term.  Any other term is interpreted as pattern and selects
  2440 all theorems matching the pattern. Available in ProofGeneral under
  2441 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2442 
  2443   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2444 
  2445 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2446 matching the current goal as introduction rule and not having "HOL."
  2447 in their name (i.e. not being defined in theory HOL).
  2448 
  2449 * Command 'thms_containing' has been discontinued in favour of
  2450 'find_theorems'; INCOMPATIBILITY.
  2451 
  2452 * Communication with Proof General is now 8bit clean, which means that
  2453 Unicode text in UTF-8 encoding may be used within theory texts (both
  2454 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2455 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2456 
  2457   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2458   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2459 
  2460 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2461 Classical Reasoner.  Typical big applications run around 2 times
  2462 faster.
  2463 
  2464 
  2465 *** Document preparation ***
  2466 
  2467 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2468 of raw sources.  Only those symbols that do not require additional
  2469 LaTeX packages (depending on comments in isabellesym.sty) are
  2470 displayed properly, everything else is left verbatim.  isatool display
  2471 and isatool print are used as front ends (these are subject to the
  2472 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2473 
  2474 * Command tags control specific markup of certain regions of text,
  2475 notably folding and hiding.  Predefined tags include "theory" (for
  2476 theory begin and end), "proof" for proof commands, and "ML" for
  2477 commands involving ML code; the additional tags "visible" and
  2478 "invisible" are unused by default.  Users may give explicit tag
  2479 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2480 interpretation of tags is determined by the LaTeX job during document
  2481 preparation: see option -V of isatool usedir, or options -n and -t of
  2482 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2483 \isadroptag.
  2484 
  2485 Several document versions may be produced at the same time via isatool
  2486 usedir (the generated index.html will link all of them).  Typical
  2487 specifications include ''-V document=theory,proof,ML'' to present
  2488 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2489 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2490 these parts without any formal replacement text.  The Isabelle site
  2491 default settings produce ''document'' and ''outline'' versions as
  2492 specified above.
  2493 
  2494 * Several new antiquotations:
  2495 
  2496   @{term_type term} prints a term with its type annotated;
  2497 
  2498   @{typeof term} prints the type of a term;
  2499 
  2500   @{const const} is the same as @{term const}, but checks that the
  2501   argument is a known logical constant;
  2502 
  2503   @{term_style style term} and @{thm_style style thm} print a term or
  2504   theorem applying a "style" to it
  2505 
  2506   @{ML text}
  2507 
  2508 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2509 definitions, equations, inequations etc., 'concl' printing only the
  2510 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2511 to print the specified premise.  TermStyle.add_style provides an ML
  2512 interface for introducing further styles.  See also the "LaTeX Sugar"
  2513 document practical applications.  The ML antiquotation prints
  2514 type-checked ML expressions verbatim.
  2515 
  2516 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2517 and 'text' support optional locale specification '(in loc)', which
  2518 specifies the default context for interpreting antiquotations.  For
  2519 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2520 
  2521 * Option 'locale=NAME' of antiquotations specifies an alternative
  2522 context interpreting the subsequent argument.  For example: @{thm
  2523 [locale=lattice] inf_assoc}.
  2524 
  2525 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2526 a proof context.
  2527 
  2528 * Proper output of antiquotations for theory commands involving a
  2529 proof context (such as 'locale' or 'theorem (in loc) ...').
  2530 
  2531 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2532 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2533 
  2534 * isatool usedir: new option -C (default true) controls whether option
  2535 -D should include a copy of the original document directory; -C false
  2536 prevents unwanted effects such as copying of administrative CVS data.
  2537 
  2538 
  2539 *** Pure ***
  2540 
  2541 * Considerably improved version of 'constdefs' command.  Now performs
  2542 automatic type-inference of declared constants; additional support for
  2543 local structure declarations (cf. locales and HOL records), see also
  2544 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2545 sequential dependencies of definitions within a single 'constdefs'
  2546 section; moreover, the declared name needs to be an identifier.  If
  2547 all fails, consider to fall back on 'consts' and 'defs' separately.
  2548 
  2549 * Improved indexed syntax and implicit structures.  First of all,
  2550 indexed syntax provides a notational device for subscripted
  2551 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2552 expressions.  Secondly, in a local context with structure
  2553 declarations, number indexes \<^sub>n or the empty index (default
  2554 number 1) refer to a certain fixed variable implicitly; option
  2555 show_structs controls printing of implicit structures.  Typical
  2556 applications of these concepts involve record types and locales.
  2557 
  2558 * New command 'no_syntax' removes grammar declarations (and
  2559 translations) resulting from the given syntax specification, which is
  2560 interpreted in the same manner as for the 'syntax' command.
  2561 
  2562 * 'Advanced' translation functions (parse_translation etc.) may depend
  2563 on the signature of the theory context being presently used for
  2564 parsing/printing, see also isar-ref manual.
  2565 
  2566 * Improved 'oracle' command provides a type-safe interface to turn an
  2567 ML expression of type theory -> T -> term into a primitive rule of
  2568 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2569 is already included here); see also FOL/ex/IffExample.thy;
  2570 INCOMPATIBILITY.
  2571 
  2572 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2573 before); "cI" is no longer bound, use "c.intro" instead.
  2574 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2575 axclasses vs. locales.
  2576 
  2577 * Improved internal renaming of symbolic identifiers -- attach primes
  2578 instead of base 26 numbers.
  2579 
  2580 * New flag show_question_marks controls printing of leading question
  2581 marks in schematic variable names.
  2582 
  2583 * In schematic variable names, *any* symbol following \<^isub> or
  2584 \<^isup> is now treated as part of the base name.  For example, the
  2585 following works without printing of awkward ".0" indexes:
  2586 
  2587   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2588     by simp
  2589 
  2590 * Inner syntax includes (*(*nested*) comments*).
  2591 
  2592 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2593 annotations as "(00...)".
  2594 
  2595 * Clear separation of logical types and nonterminals, where the latter
  2596 may only occur in 'syntax' specifications or type abbreviations.
  2597 Before that distinction was only partially implemented via type class
  2598 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2599 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2600 exotic syntax specifications may require further adaption
  2601 (e.g. Cube/Cube.thy).
  2602 
  2603 * Removed obsolete type class "logic", use the top sort {} instead.
  2604 Note that non-logical types should be declared as 'nonterminals'
  2605 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2606 specifications.
  2607 
  2608 * Attributes 'induct' and 'cases': type or set names may now be
  2609 locally fixed variables as well.
  2610 
  2611 * Simplifier: can now control the depth to which conditional rewriting
  2612 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2613 Limit.
  2614 
  2615 * Simplifier: simplification procedures may now take the current
  2616 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2617 interface), which is very useful for calling the Simplifier
  2618 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2619 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2620 low-level mk_simproc no longer applies Logic.varify internally, to
  2621 allow for use in a context of fixed variables.
  2622 
  2623 * thin_tac now works even if the assumption being deleted contains !!
  2624 or ==>.  More generally, erule now works even if the major premise of
  2625 the elimination rule contains !! or ==>.
  2626 
  2627 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2628 
  2629 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2630 from Pure, which contains all common declarations already.  Both
  2631 theories are defined via plain Isabelle/Isar .thy files.
  2632 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2633 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2634 use isatool fixcpure to adapt your theory and ML sources.
  2635 
  2636 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2637 selections of theorems in named facts via index ranges.
  2638 
  2639 * 'print_theorems': in theory mode, really print the difference
  2640 wrt. the last state (works for interactive theory development only),
  2641 in proof mode print all local facts (cf. 'print_facts');
  2642 
  2643 * 'hide': option '(open)' hides only base names.
  2644 
  2645 * More efficient treatment of intermediate checkpoints in interactive
  2646 theory development.
  2647 
  2648 * Code generator is now invoked via code_module (incremental code
  2649 generation) and code_library (modular code generation, ML structures
  2650 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2651 must be quoted when used as identifiers.
  2652 
  2653 * New 'value' command for reading, evaluating and printing terms using
  2654 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2655 quoted when used as identifier.
  2656 
  2657 
  2658 *** Locales ***
  2659 
  2660 * New commands for the interpretation of locale expressions in
  2661 theories (1), locales (2) and proof contexts (3).  These generate
  2662 proof obligations from the expression specification.  After the
  2663 obligations have been discharged, theorems of the expression are added
  2664 to the theory, target locale or proof context.  The synopsis of the
  2665 commands is a follows:
  2666 
  2667   (1) interpretation expr inst
  2668   (2) interpretation target < expr
  2669   (3) interpret expr inst
  2670 
  2671 Interpretation in theories and proof contexts require a parameter
  2672 instantiation of terms from the current context.  This is applied to
  2673 specifications and theorems of the interpreted expression.
  2674 Interpretation in locales only permits parameter renaming through the
  2675 locale expression.  Interpretation is smart in that interpretations
  2676 that are active already do not occur in proof obligations, neither are
  2677 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2678 inspect active interpretations of a particular locale.  For details,
  2679 see the Isar Reference manual.  Examples can be found in
  2680 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2681 
  2682 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2683 'interpret' instead.
  2684 
  2685 * New context element 'constrains' for adding type constraints to
  2686 parameters.
  2687 
  2688 * Context expressions: renaming of parameters with syntax
  2689 redeclaration.
  2690 
  2691 * Locale declaration: 'includes' disallowed.
  2692 
  2693 * Proper static binding of attribute syntax -- i.e. types / terms /
  2694 facts mentioned as arguments are always those of the locale definition
  2695 context, independently of the context of later invocations.  Moreover,
  2696 locale operations (renaming and type / term instantiation) are applied
  2697 to attribute arguments as expected.
  2698 
  2699 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2700 actual attributes; rare situations may require Attrib.attribute to
  2701 embed those attributes into Attrib.src that lack concrete syntax.
  2702 Attribute implementations need to cooperate properly with the static
  2703 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2704 Attrib.XXX_thm etc. already do the right thing without further
  2705 intervention.  Only unusual applications -- such as "where" or "of"
  2706 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2707 on the context and the facts involved -- may have to assign parsed
  2708 values to argument tokens explicitly.
  2709 
  2710 * Changed parameter management in theorem generation for long goal
  2711 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2712 theorem statement in rare situations.
  2713 
  2714 * Locale inspection command 'print_locale' omits notes elements.  Use
  2715 'print_locale!' to have them included in the output.
  2716 
  2717 
  2718 *** Provers ***
  2719 
  2720 * Provers/hypsubst.ML: improved version of the subst method, for
  2721 single-step rewriting: it now works in bound variable contexts. New is
  2722 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2723 rewrite a different subterm than the original subst method, which is
  2724 still available as 'simplesubst'.
  2725 
  2726 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2727 and quasi orders.
  2728 
  2729 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2730 reflexive-transitive closure of relations.
  2731 
  2732 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2733 limit (previously hard-coded with a value of 20) user-definable.
  2734 
  2735 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2736 is peformed already.  Object-logics merely need to finish their
  2737 initial simpset configuration as before.  INCOMPATIBILITY.
  2738 
  2739 
  2740 *** HOL ***
  2741 
  2742 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2743 
  2744   syntax (epsilon)
  2745     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2746 
  2747 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2748 and x-symbol; use option '-m epsilon' to get it actually printed.
  2749 Moreover, the mathematically important symbolic identifier \<epsilon>
  2750 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2751 
  2752 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2753 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2754 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2755 support corresponding Isar calculations.
  2756 
  2757 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2758 instead of ":".
  2759 
  2760 * theory SetInterval: changed the syntax for open intervals:
  2761 
  2762   Old       New
  2763   {..n(}    {..<n}
  2764   {)n..}    {n<..}
  2765   {m..n(}   {m..<n}
  2766   {)m..n}   {m<..n}
  2767   {)m..n(}  {m<..<n}
  2768 
  2769 The old syntax is still supported but will disappear in the next
  2770 release.  For conversion use the following Emacs search and replace
  2771 patterns (these are not perfect but work quite well):
  2772 
  2773   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2774   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2775 
  2776 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2777 equalities in commutative rings; method 'algebra' provides a generic
  2778 interface.
  2779 
  2780 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2781 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2782 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2783 be a tuple pattern.
  2784 
  2785 Some new syntax forms are available:
  2786 
  2787   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2788   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2789   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2790   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2791 
  2792 The latter form "\<Sum>x < k. e" used to be based on a separate
  2793 function "Summation", which has been discontinued.
  2794 
  2795 * theory Finite_Set: in structured induction proofs, the insert case
  2796 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2797 (insert F x)'.
  2798 
  2799 * The 'refute' command has been extended to support a much larger
  2800 fragment of HOL, including axiomatic type classes, constdefs and
  2801 typedefs, inductive datatypes and recursion.
  2802 
  2803 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2804 Requires zChaff with proof generation to be installed.  See
  2805 HOL/ex/SAT_Examples.thy for examples.
  2806 
  2807 * Datatype induction via method 'induct' now preserves the name of the
  2808 induction variable. For example, when proving P(xs::'a list) by
  2809 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2810 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2811 in unstructured proof scripts.
  2812 
  2813 * Reworked implementation of records.  Improved scalability for
  2814 records with many fields, avoiding performance problems for type
  2815 inference. Records are no longer composed of nested field types, but
  2816 of nested extension types. Therefore the record type only grows linear
  2817 in the number of extensions and not in the number of fields.  The
  2818 top-level (users) view on records is preserved.  Potential
  2819 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2820 old record representation. The type generated for a record is called
  2821 <record_name>_ext_type.
  2822 
  2823 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2824 proofs triggered by a record definition or a simproc (if
  2825 quick_and_dirty is enabled).  Definitions of large records can take
  2826 quite long.
  2827 
  2828 New simproc record_upd_simproc for simplification of multiple record
  2829 updates enabled by default.  Moreover, trivial updates are also
  2830 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2831 occasionally, since simplification is more powerful by default.
  2832 
  2833 * typedef: proper support for polymorphic sets, which contain extra
  2834 type-variables in the term.
  2835 
  2836 * Simplifier: automatically reasons about transitivity chains
  2837 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2838 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2839 old proofs break occasionally as simplification may now solve more
  2840 goals than previously.
  2841 
  2842 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2843 present.  Works for all partial orders (class "order"), in particular
  2844 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2845 just like y <= x.
  2846 
  2847 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2848 bound variable or a constant then the let is unfolded.  Otherwise
  2849 first a is simplified to b, and then f b is simplified to g. If
  2850 possible we abstract b from g arriving at "let x = b in h x",
  2851 otherwise we unfold the let and arrive at g.  The simproc can be
  2852 enabled/disabled by the reference use_let_simproc.  Potential
  2853 INCOMPATIBILITY since simplification is more powerful by default.
  2854 
  2855 * Classical reasoning: the meson method now accepts theorems as arguments.
  2856 
  2857 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2858 jobs to provide advice on the provability of subgoals.
  2859 
  2860 * Theory OrderedGroup and Ring_and_Field: various additions and
  2861 improvements to faciliate calculations involving equalities and
  2862 inequalities.
  2863 
  2864 The following theorems have been eliminated or modified
  2865 (INCOMPATIBILITY):
  2866 
  2867   abs_eq             now named abs_of_nonneg
  2868   abs_of_ge_0        now named abs_of_nonneg
  2869   abs_minus_eq       now named abs_of_nonpos
  2870   imp_abs_id         now named abs_of_nonneg
  2871   imp_abs_neg_id     now named abs_of_nonpos
  2872   mult_pos           now named mult_pos_pos
  2873   mult_pos_le        now named mult_nonneg_nonneg
  2874   mult_pos_neg_le    now named mult_nonneg_nonpos
  2875   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2876   mult_neg           now named mult_neg_neg
  2877   mult_neg_le        now named mult_nonpos_nonpos
  2878 
  2879 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2880      
  2881      zero_le_square
  2882      not_square_less_zero 
  2883 
  2884   The following lemmas have been deleted from Real/RealPow:
  2885   
  2886      realpow_zero_zero
  2887      realpow_two
  2888      realpow_less
  2889      zero_le_power
  2890      realpow_two_le
  2891      abs_realpow_two
  2892      realpow_two_abs     
  2893 
  2894 * Theory Parity: added rules for simplifying exponents.
  2895 
  2896 * Theory List:
  2897 
  2898 The following theorems have been eliminated or modified
  2899 (INCOMPATIBILITY):
  2900 
  2901   list_all_Nil       now named list_all.simps(1)
  2902   list_all_Cons      now named list_all.simps(2)
  2903   list_all_conv      now named list_all_iff
  2904   set_mem_eq         now named mem_iff
  2905 
  2906 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2907 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2908 
  2909 
  2910 *** HOL-Complex ***
  2911 
  2912 * Theory RealDef: better support for embedding natural numbers and
  2913 integers in the reals.
  2914 
  2915 The following theorems have been eliminated or modified
  2916 (INCOMPATIBILITY):
  2917 
  2918   exp_ge_add_one_self  now requires no hypotheses
  2919   real_of_int_add      reversed direction of equality (use [symmetric])
  2920   real_of_int_minus    reversed direction of equality (use [symmetric])
  2921   real_of_int_diff     reversed direction of equality (use [symmetric])
  2922   real_of_int_mult     reversed direction of equality (use [symmetric])
  2923 
  2924 * Theory RComplete: expanded support for floor and ceiling functions.
  2925 
  2926 * Theory Ln is new, with properties of the natural logarithm
  2927 
  2928 * Hyperreal: There is a new type constructor "star" for making
  2929 nonstandard types.  The old type names are now type synonyms:
  2930 
  2931   hypreal = real star
  2932   hypnat = nat star
  2933   hcomplex = complex star
  2934 
  2935 * Hyperreal: Many groups of similarly-defined constants have been
  2936 replaced by polymorphic versions (INCOMPATIBILITY):
  2937 
  2938   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2939 
  2940   starset      <-- starsetNat, starsetC
  2941   *s*          <-- *sNat*, *sc*
  2942   starset_n    <-- starsetNat_n, starsetC_n
  2943   *sn*         <-- *sNatn*, *scn*
  2944   InternalSets <-- InternalNatSets, InternalCSets
  2945 
  2946   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2947   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2948   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2949   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2950   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2951 
  2952 * Hyperreal: Many type-specific theorems have been removed in favor of
  2953 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2954 
  2955   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2956   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2957   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2958   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2959   right_minus <-- hypreal_add_minus
  2960   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2961   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2962   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2963   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2964   mult_1_right <-- hcomplex_mult_one_right
  2965   mult_zero_left <-- hcomplex_mult_zero_left
  2966   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2967   right_distrib <-- hypnat_add_mult_distrib2
  2968   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2969   right_inverse <-- hypreal_mult_inverse
  2970   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2971   order_refl <-- {hypreal,hypnat}_le_refl
  2972   order_trans <-- {hypreal,hypnat}_le_trans
  2973   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2974   order_less_le <-- {hypreal,hypnat}_less_le
  2975   linorder_linear <-- {hypreal,hypnat}_le_linear
  2976   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2977   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2978   add_nonneg_nonneg <-- hypreal_le_add_order
  2979 
  2980 * Hyperreal: Separate theorems having to do with type-specific
  2981 versions of constants have been merged into theorems that apply to the
  2982 new polymorphic constants (INCOMPATIBILITY):
  2983 
  2984   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2985   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2986   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2987   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2988   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2989   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2990   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2991   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2992   STAR_diff <-- {STAR,STARC}_diff
  2993   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2994     STARC_hcomplex_of_complex}_image_subset
  2995   starset_n_Un <-- starset{Nat,C}_n_Un
  2996   starset_n_Int <-- starset{Nat,C}_n_Int
  2997   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2998   starset_n_diff <-- starset{Nat,C}_n_diff
  2999   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3000   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3001   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3002   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3003   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3004   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3005   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3006   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3007   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3008   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3009   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3010   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3011   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3012   starfun_diff <-- starfun{C,RC,CR}_diff
  3013   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3014   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3015   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3016   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3017   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3018   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3019   starfun_Id <-- starfunC_Id
  3020   starfun_approx <-- starfun{Nat,CR}_approx
  3021   starfun_capprox <-- starfun{C,RC}_capprox
  3022   starfun_abs <-- starfunNat_rabs
  3023   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3024   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3025   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3026   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3027   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3028   starfun_add_approx <-- starfunCR_add_approx
  3029   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3030   starfun_divide <-- starfun{C,CR,RC}_divide
  3031   starfun_n <-- starfun{Nat,C}_n
  3032   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3033   starfun_n_add <-- starfun{Nat,C}_n_add
  3034   starfun_n_add_minus <-- starfunNat_n_add_minus
  3035   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3036   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3037   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3038 
  3039   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3040   star_n_minus <-- {hypreal,hcomplex}_minus
  3041   star_n_diff <-- {hypreal,hcomplex}_diff
  3042   star_n_mult <-- {hypreal,hcomplex}_mult
  3043   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3044   star_n_le <-- {hypreal,hypnat}_le
  3045   star_n_less <-- {hypreal,hypnat}_less
  3046   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3047   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3048   star_n_abs <-- hypreal_hrabs
  3049   star_n_divide <-- hcomplex_divide
  3050 
  3051   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3052   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3053   star_of_diff <-- hypreal_of_real_diff
  3054   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3055   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3056   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3057   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3058   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3059   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3060   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3061   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3062   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3063   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3064   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3065   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3066   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3067   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3068   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3069   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3070   star_of_power <-- hypreal_of_real_power
  3071   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3072 
  3073 * Hyperreal: new method "transfer" that implements the transfer
  3074 principle of nonstandard analysis. With a subgoal that mentions
  3075 nonstandard types like "'a star", the command "apply transfer"
  3076 replaces it with an equivalent one that mentions only standard types.
  3077 To be successful, all free variables must have standard types; non-
  3078 standard variables must have explicit universal quantifiers.
  3079 
  3080 * Hyperreal: A theory of Taylor series.
  3081 
  3082 
  3083 *** HOLCF ***
  3084 
  3085 * Discontinued special version of 'constdefs' (which used to support
  3086 continuous functions) in favor of the general Pure one with full
  3087 type-inference.
  3088 
  3089 * New simplification procedure for solving continuity conditions; it
  3090 is much faster on terms with many nested lambda abstractions (cubic
  3091 instead of exponential time).
  3092 
  3093 * New syntax for domain package: selector names are now optional.
  3094 Parentheses should be omitted unless argument is lazy, for example:
  3095 
  3096   domain 'a stream = cons "'a" (lazy "'a stream")
  3097 
  3098 * New command 'fixrec' for defining recursive functions with pattern
  3099 matching; defining multiple functions with mutual recursion is also
  3100 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3101 sinr, or any data constructor defined by the domain package. The given
  3102 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3103 syntax and examples.
  3104 
  3105 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3106 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3107 but the proof obligation additionally includes an admissibility
  3108 requirement. The packages generate instances of class cpo or pcpo,
  3109 with continuity and strictness theorems for Rep and Abs.
  3110 
  3111 * HOLCF: Many theorems have been renamed according to a more standard naming
  3112 scheme (INCOMPATIBILITY):
  3113 
  3114   foo_inject:  "foo$x = foo$y ==> x = y"
  3115   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3116   foo_less:    "(foo$x << foo$y) = (x << y)"
  3117   foo_strict:  "foo$UU = UU"
  3118   foo_defined: "... ==> foo$x ~= UU"
  3119   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3120 
  3121 
  3122 *** ZF ***
  3123 
  3124 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3125 including the First Isomorphism Theorem (on quotienting by the kernel
  3126 of a homomorphism).
  3127 
  3128 * ZF/Simplifier: install second copy of type solver that actually
  3129 makes use of TC rules declared to Isar proof contexts (or locales);
  3130 the old version is still required for ML proof scripts.
  3131 
  3132 
  3133 *** Cube ***
  3134 
  3135 * Converted to Isar theory format; use locales instead of axiomatic
  3136 theories.
  3137 
  3138 
  3139 *** ML ***
  3140 
  3141 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3142 for ||>, ||>>, |>>,
  3143 
  3144 * Pure/library.ML no longer defines its own option datatype, but uses
  3145 that of the SML basis, which has constructors NONE and SOME instead of
  3146 None and Some, as well as exception Option.Option instead of OPTION.
  3147 The functions the, if_none, is_some, is_none have been adapted
  3148 accordingly, while Option.map replaces apsome.
  3149 
  3150 * Pure/library.ML: the exception LIST has been given up in favour of
  3151 the standard exceptions Empty and Subscript, as well as
  3152 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3153 superceded by the standard hd and tl functions etc.
  3154 
  3155 A number of basic list functions are no longer exported to the ML
  3156 toplevel, as they are variants of predefined functions.  The following
  3157 suggests how one can translate existing code:
  3158 
  3159     rev_append xs ys = List.revAppend (xs, ys)
  3160     nth_elem (i, xs) = List.nth (xs, i)
  3161     last_elem xs = List.last xs
  3162     flat xss = List.concat xss
  3163     seq fs = List.app fs
  3164     partition P xs = List.partition P xs
  3165     mapfilter f xs = List.mapPartial f xs
  3166 
  3167 * Pure/library.ML: several combinators for linear functional
  3168 transformations, notably reverse application and composition:
  3169 
  3170   x |> f                f #> g
  3171   (x, y) |-> f          f #-> g
  3172 
  3173 * Pure/library.ML: introduced/changed precedence of infix operators:
  3174 
  3175   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3176   infix 2 ?;
  3177   infix 3 o oo ooo oooo;
  3178   infix 4 ~~ upto downto;
  3179 
  3180 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3181 infix operators.
  3182 
  3183 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3184 fold_map support linear functional transformations and nesting.  For
  3185 example:
  3186 
  3187   fold f [x1, ..., xN] y =
  3188     y |> f x1 |> ... |> f xN
  3189 
  3190   (fold o fold) f [xs1, ..., xsN] y =
  3191     y |> fold f xs1 |> ... |> fold f xsN
  3192 
  3193   fold f [x1, ..., xN] =
  3194     f x1 #> ... #> f xN
  3195 
  3196   (fold o fold) f [xs1, ..., xsN] =
  3197     fold f xs1 #> ... #> fold f xsN
  3198 
  3199 * Pure/library.ML: the following selectors on type 'a option are
  3200 available:
  3201 
  3202   the:               'a option -> 'a  (*partial*)
  3203   these:             'a option -> 'a  where 'a = 'b list
  3204   the_default: 'a -> 'a option -> 'a
  3205   the_list:          'a option -> 'a list
  3206 
  3207 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3208 basic operations for association lists, following natural argument
  3209 order; moreover the explicit equality predicate passed here avoids
  3210 potentially expensive polymorphic runtime equality checks.
  3211 The old functions may be expressed as follows:
  3212 
  3213   assoc = uncurry (AList.lookup (op =))
  3214   assocs = these oo AList.lookup (op =)
  3215   overwrite = uncurry (AList.update (op =)) o swap
  3216 
  3217 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3218 
  3219   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3220   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3221 
  3222 replacing make_keylist and keyfilter (occassionally used)
  3223 Naive rewrites:
  3224 
  3225   make_keylist = AList.make
  3226   keyfilter = AList.find (op =)
  3227 
  3228 * eq_fst and eq_snd now take explicit equality parameter, thus
  3229   avoiding eqtypes. Naive rewrites:
  3230 
  3231     eq_fst = eq_fst (op =)
  3232     eq_snd = eq_snd (op =)
  3233 
  3234 * Removed deprecated apl and apr (rarely used).
  3235   Naive rewrites:
  3236 
  3237     apl (n, op) =>>= curry op n
  3238     apr (op, m) =>>= fn n => op (n, m)
  3239 
  3240 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3241 provides a reasonably efficient light-weight implementation of sets as
  3242 lists.
  3243 
  3244 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3245 few new operations; existing lookup and update are now curried to
  3246 follow natural argument order (for use with fold etc.);
  3247 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3248 
  3249 * Pure/General: output via the Isabelle channels of
  3250 writeln/warning/error etc. is now passed through Output.output, with a
  3251 hook for arbitrary transformations depending on the print_mode
  3252 (cf. Output.add_mode -- the first active mode that provides a output
  3253 function wins).  Already formatted output may be embedded into further
  3254 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3255 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3256 accommodate easy composition of diagnostic messages etc.  Programmers
  3257 rarely need to care about Output.output or Output.raw at all, with
  3258 some notable exceptions: Output.output is required when bypassing the
  3259 standard channels (writeln etc.), or in token translations to produce
  3260 properly formatted results; Output.raw is required when capturing
  3261 already output material that will eventually be presented to the user
  3262 a second time.  For the default print mode, both Output.output and
  3263 Output.raw have no effect.
  3264 
  3265 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3266 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3267 cumulative results are displayed at the end of a batch session.
  3268 
  3269 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3270 replaced by File.platform_path and File.shell_path (with appropriate
  3271 hooks).  This provides a clean interface for unusual systems where the
  3272 internal and external process view of file names are different.
  3273 
  3274 * Pure: more efficient orders for basic syntactic entities: added
  3275 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3276 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3277 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3278 orders now -- potential INCOMPATIBILITY for code that depends on a
  3279 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3280 Library.sort_strings on result).
  3281 
  3282 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3283 fold_types traverse types/terms from left to right, observing natural
  3284 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3285 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3286 
  3287 * Pure: name spaces have been refined, with significant changes of the
  3288 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3289 to extern(_table).  The plain name entry path is superceded by a
  3290 general 'naming' context, which also includes the 'policy' to produce
  3291 a fully qualified name and external accesses of a fully qualified
  3292 name; NameSpace.extend is superceded by context dependent
  3293 Sign.declare_name.  Several theory and proof context operations modify
  3294 the naming context.  Especially note Theory.restore_naming and
  3295 ProofContext.restore_naming to get back to a sane state; note that
  3296 Theory.add_path is no longer sufficient to recover from
  3297 Theory.absolute_path in particular.
  3298 
  3299 * Pure: new flags short_names (default false) and unique_names
  3300 (default true) for controlling output of qualified names.  If
  3301 short_names is set, names are printed unqualified.  If unique_names is
  3302 reset, the name prefix is reduced to the minimum required to achieve
  3303 the original result when interning again, even if there is an overlap
  3304 with earlier declarations.
  3305 
  3306 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3307 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3308 (useful for printing error messages).  INCOMPATIBILITY.
  3309 
  3310 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3311 Theory.theory are now identified, referring to the universal
  3312 Context.theory (see Pure/context.ML).  Actual signature and theory
  3313 content is managed as theory data.  The old code and interfaces were
  3314 spread over many files and structures; the new arrangement introduces
  3315 considerable INCOMPATIBILITY to gain more clarity:
  3316 
  3317   Context -- theory management operations (name, identity, inclusion,
  3318     parents, ancestors, merge, etc.), plus generic theory data;
  3319 
  3320   Sign -- logical signature and syntax operations (declaring consts,
  3321     types, etc.), plus certify/read for common entities;
  3322 
  3323   Theory -- logical theory operations (stating axioms, definitions,
  3324     oracles), plus a copy of logical signature operations (consts,
  3325     types, etc.); also a few basic management operations (Theory.copy,
  3326     Theory.merge, etc.)
  3327 
  3328 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3329 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3330 for convenience -- they merely return the theory.
  3331 
  3332 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3333 
  3334 * Pure: the Isar proof context type is already defined early in Pure
  3335 as Context.proof (note that ProofContext.context and Proof.context are
  3336 aliases, where the latter is the preferred name).  This enables other
  3337 Isabelle components to refer to that type even before Isar is present.
  3338 
  3339 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3340 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3341 any of these kinds.  For example, Sign.intern typeK is now
  3342 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3343 Theory.hide_types.  Also note that former
  3344 Theory.hide_classes/types/consts are now
  3345 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3346 internalize their arguments!  INCOMPATIBILITY.
  3347 
  3348 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3349 datatype thmref (with constructors Name and NameSelection) instead of
  3350 plain string -- INCOMPATIBILITY;
  3351 
  3352 * Pure: cases produced by proof methods specify options, where NONE
  3353 means to remove case bindings -- INCOMPATIBILITY in
  3354 (RAW_)METHOD_CASES.
  3355 
  3356 * Pure: the following operations retrieve axioms or theorems from a
  3357 theory node or theory hierarchy, respectively:
  3358 
  3359   Theory.axioms_of: theory -> (string * term) list
  3360   Theory.all_axioms_of: theory -> (string * term) list
  3361   PureThy.thms_of: theory -> (string * thm) list
  3362   PureThy.all_thms_of: theory -> (string * thm) list
  3363 
  3364 * Pure: print_tac now outputs the goal through the trace channel.
  3365 
  3366 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3367 Reference Toplevel.debug (default false) controls detailed printing
  3368 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3369 controls execution profiling -- set to 1 for time and 2 for space
  3370 (both increase the runtime).
  3371 
  3372 * Isar session: The initial use of ROOT.ML is now always timed,
  3373 i.e. the log will show the actual process times, in contrast to the
  3374 elapsed wall-clock time that the outer shell wrapper produces.
  3375 
  3376 * Simplifier: improved handling of bound variables (nameless
  3377 representation, avoid allocating new strings).  Simprocs that invoke
  3378 the Simplifier recursively should use Simplifier.inherit_bounds to
  3379 avoid local name clashes.  Failure to do so produces warnings
  3380 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3381 for further details.
  3382 
  3383 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3384 bindings for all theorems stored within a given theory; this may help
  3385 in porting non-Isar theories to Isar ones, while keeping ML proof
  3386 scripts for the time being.
  3387 
  3388 * ML operator HTML.with_charset specifies the charset begin used for
  3389 generated HTML files.  For example:
  3390 
  3391   HTML.with_charset "utf-8" use_thy "Hebrew";
  3392   HTML.with_charset "utf-8" use_thy "Chinese";
  3393 
  3394 
  3395 *** System ***
  3396 
  3397 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3398 isabelle, isatool etc.).
  3399 
  3400 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3401 isatool doc, isatool mkdir, display_drafts etc.).
  3402 
  3403 * isatool usedir: option -f allows specification of the ML file to be
  3404 used by Isabelle; default is ROOT.ML.
  3405 
  3406 * New isatool version outputs the version identifier of the Isabelle
  3407 distribution being used.
  3408 
  3409 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3410 (containing Boolean satisfiability problems) into Isabelle/HOL
  3411 theories.
  3412 
  3413 
  3414 
  3415 New in Isabelle2004 (April 2004)
  3416 --------------------------------
  3417 
  3418 *** General ***
  3419 
  3420 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3421   Replaces linorder.ML.
  3422 
  3423 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3424   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3425   (\<a>...\<z>), are now considered normal letters, and can therefore
  3426   be used anywhere where an ASCII letter (a...zA...Z) has until
  3427   now. COMPATIBILITY: This obviously changes the parsing of some
  3428   terms, especially where a symbol has been used as a binder, say
  3429   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3430   as an identifier.  Fix it by inserting a space around former
  3431   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3432   existing theory and ML files.
  3433 
  3434 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3435 
  3436 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3437   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3438   a normal (but invisible) letter. For multiple letter subscripts repeat
  3439   \<^isub> like this: x\<^isub>1\<^isub>2.
  3440 
  3441 * Pure: There are now sub-/superscripts that can span more than one
  3442   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3443   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3444   superscript. The new control characters are not identifier parts.
  3445 
  3446 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3447   content of "..." to the latex file instead of \isacntrl... . The "..."
  3448   may consist of any printable characters excluding the end bracket >.
  3449 
  3450 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3451   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3452   declare constants "final", which prevents their being given a definition
  3453   later.  It is useful for constants whose behaviour is fixed axiomatically
  3454   rather than definitionally, such as the meta-logic connectives.
  3455 
  3456 * Pure: 'instance' now handles general arities with general sorts
  3457   (i.e. intersections of classes),
  3458 
  3459 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3460   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3461   It can be changed to alter the colors/layout of generated pages.
  3462 
  3463 
  3464 *** Isar ***
  3465 
  3466 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3467   cut_tac, subgoal_tac and thin_tac:
  3468   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3469     locales are no longer forced to write Isar proof scripts.
  3470     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3471     emulations.
  3472   - INCOMPATIBILITY: names of variables to be instantiated may no
  3473     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3474     This is consistent with the instantiation attribute "where".
  3475 
  3476 * Attributes "where" and "of":
  3477   - Now take type variables of instantiated theorem into account when reading
  3478     the instantiation string.  This fixes a bug that caused instantiated
  3479     theorems to have too special types in some circumstances.
  3480   - "where" permits explicit instantiations of type variables.
  3481 
  3482 * Calculation commands "moreover" and "also" no longer interfere with
  3483   current facts ("this"), admitting arbitrary combinations with "then"
  3484   and derived forms.
  3485 
  3486 * Locales:
  3487   - Goal statements involving the context element "includes" no longer
  3488     generate theorems with internal delta predicates (those ending on
  3489     "_axioms") in the premise.
  3490     Resolve particular premise with <locale>.intro to obtain old form.
  3491   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3492     specification and "includes" elements in goal statement.
  3493   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3494     [intro?] and [elim?] (respectively) by default.
  3495   - Experimental command for instantiation of locales in proof contexts:
  3496         instantiate <label>[<attrs>]: <loc>
  3497     Instantiates locale <loc> and adds all its theorems to the current context
  3498     taking into account their attributes.  Label and attrs are optional
  3499     modifiers, like in theorem declarations.  If present, names of
  3500     instantiated theorems are qualified with <label>, and the attributes
  3501     <attrs> are applied after any attributes these theorems might have already.
  3502       If the locale has assumptions, a chained fact of the form
  3503     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3504     are derived.  The command does not support old-style locales declared
  3505     with "locale (open)".
  3506       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3507 
  3508 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3509   (Isar) contexts.
  3510 
  3511 
  3512 *** HOL ***
  3513 
  3514 * Proof import: new image HOL4 contains the imported library from
  3515   the HOL4 system with about 2500 theorems. It is imported by
  3516   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3517   can be used like any other Isabelle image.  See
  3518   HOL/Import/HOL/README for more information.
  3519 
  3520 * Simplifier:
  3521   - Much improved handling of linear and partial orders.
  3522     Reasoners for linear and partial orders are set up for type classes
  3523     "linorder" and "order" respectively, and are added to the default simpset
  3524     as solvers.  This means that the simplifier can build transitivity chains
  3525     to solve goals from the assumptions.
  3526   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3527     of blast or auto after simplification become unnecessary because the goal
  3528     is solved by simplification already.
  3529 
  3530 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3531     all proved in axiomatic type classes for semirings, rings and fields.
  3532 
  3533 * Numerics:
  3534   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3535     now formalized using the Ring_and_Field theory mentioned above.
  3536   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3537     than before, because now they are set up once in a generic manner.
  3538   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3539     Look for the general versions in Ring_and_Field (and Power if they concern
  3540     exponentiation).
  3541 
  3542 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3543 
  3544 * Records:
  3545   - Record types are now by default printed with their type abbreviation
  3546     instead of the list of all field types. This can be configured via
  3547     the reference "print_record_type_abbr".
  3548   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3549     (not enabled by default).
  3550   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3551     EX x. x = sel r to True (not enabled by default).
  3552   - Tactic "record_split_simp_tac" to split and simplify records added.
  3553 
  3554 * 'specification' command added, allowing for definition by
  3555   specification.  There is also an 'ax_specification' command that
  3556   introduces the new constants axiomatically.
  3557 
  3558 * arith(_tac) is now able to generate counterexamples for reals as well.
  3559 
  3560 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3561 
  3562 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3563   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3564 
  3565 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3566   matrix theory to linear programming.
  3567 
  3568 * Unions and Intersections:
  3569   The latex output syntax of UN and INT has been changed
  3570   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3571   i.e. the index formulae has become a subscript.
  3572   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3573 
  3574 * Unions and Intersections over Intervals:
  3575   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3576   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3577   like in normal math, and corresponding versions for < and for intersection.
  3578 
  3579 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3580   lexicographic dictonary ordering has been added as "lexord".
  3581 
  3582 * ML: the legacy theory structures Int and List have been removed. They had
  3583   conflicted with ML Basis Library structures having the same names.
  3584 
  3585 * 'refute' command added to search for (finite) countermodels.  Only works
  3586   for a fragment of HOL.  The installation of an external SAT solver is
  3587   highly recommended.  See "HOL/Refute.thy" for details.
  3588 
  3589 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3590   formulae under an assignment of free variables to random values.
  3591   In contrast to 'refute', it can deal with inductive datatypes,
  3592   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3593   for examples.
  3594 
  3595 
  3596 *** HOLCF ***
  3597 
  3598 * Streams now come with concatenation and are part of the HOLCF image
  3599 
  3600 
  3601 
  3602 New in Isabelle2003 (May 2003)
  3603 ------------------------------
  3604 
  3605 *** General ***
  3606 
  3607 * Provers/simplifier:
  3608 
  3609   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3610     Assumptions are now subject to complete mutual simplification,
  3611     not just from left to right. The simplifier now preserves
  3612     the order of assumptions.
  3613 
  3614     Potential INCOMPATIBILITY:
  3615 
  3616     -- simp sometimes diverges where the old version did
  3617        not, e.g. invoking simp on the goal
  3618 
  3619         [| P (f x); y = x; f x = f y |] ==> Q
  3620 
  3621        now gives rise to the infinite reduction sequence
  3622 
  3623         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3624 
  3625        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3626        kind of problem.
  3627 
  3628     -- Tactics combining classical reasoner and simplification (such as auto)
  3629        are also affected by this change, because many of them rely on
  3630        simp. They may sometimes diverge as well or yield a different numbers
  3631        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3632        in case of problems. Sometimes subsequent calls to the classical
  3633        reasoner will fail because a preceeding call to the simplifier too
  3634        eagerly simplified the goal, e.g. deleted redundant premises.
  3635 
  3636   - The simplifier trace now shows the names of the applied rewrite rules
  3637 
  3638   - You can limit the number of recursive invocations of the simplifier
  3639     during conditional rewriting (where the simplifie tries to solve the
  3640     conditions before applying the rewrite rule):
  3641     ML "simp_depth_limit := n"
  3642     where n is an integer. Thus you can force termination where previously
  3643     the simplifier would diverge.
  3644 
  3645   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3646 
  3647   - No longer aborts on failed congruence proof.  Instead, the
  3648     congruence is ignored.
  3649 
  3650 * Pure: New generic framework for extracting programs from constructive
  3651   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3652   as HOL/Extraction for some case studies.
  3653 
  3654 * Pure: The main goal of the proof state is no longer shown by default, only
  3655 the subgoals. This behaviour is controlled by a new flag.
  3656    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3657 (ML: Proof.show_main_goal).
  3658 
  3659 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3660 rules whose conclusion matches subgoal 1:
  3661       PG menu: Isabelle/Isar -> Show me -> matching rules
  3662 The rules are ordered by how closely they match the subgoal.
  3663 In particular, rules that solve a subgoal outright are displayed first
  3664 (or rather last, the way they are printed).
  3665 (ML: ProofGeneral.print_intros())
  3666 
  3667 * Pure: New flag trace_unify_fail causes unification to print
  3668 diagnostic information (PG: in trace buffer) when it fails. This is
  3669 useful for figuring out why single step proofs like rule, erule or
  3670 assumption failed.
  3671 
  3672 * Pure: Locale specifications now produce predicate definitions
  3673 according to the body of text (covering assumptions modulo local
  3674 definitions); predicate "loc_axioms" covers newly introduced text,
  3675 while "loc" is cumulative wrt. all included locale expressions; the
  3676 latter view is presented only on export into the global theory
  3677 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3678 on the old view without predicates;
  3679 
  3680 * Pure: predefined locales "var" and "struct" are useful for sharing
  3681 parameters (as in CASL, for example); just specify something like
  3682 ``var x + var y + struct M'' as import;
  3683 
  3684 * Pure: improved thms_containing: proper indexing of facts instead of
  3685 raw theorems; check validity of results wrt. current name space;
  3686 include local facts of proof configuration (also covers active
  3687 locales), cover fixed variables in index; may use "_" in term
  3688 specification; an optional limit for the number of printed facts may
  3689 be given (the default is 40);
  3690 
  3691 * Pure: disallow duplicate fact bindings within new-style theory files
  3692 (batch-mode only);
  3693 
  3694 * Provers: improved induct method: assumptions introduced by case
  3695 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3696 the goal statement); "foo" still refers to all facts collectively;
  3697 
  3698 * Provers: the function blast.overloaded has been removed: all constants
  3699 are regarded as potentially overloaded, which improves robustness in exchange
  3700 for slight decrease in efficiency;
  3701 
  3702 * Provers/linorder: New generic prover for transitivity reasoning over
  3703 linear orders.  Note: this prover is not efficient!
  3704 
  3705 * Isar: preview of problems to finish 'show' now produce an error
  3706 rather than just a warning (in interactive mode);
  3707 
  3708 
  3709 *** HOL ***
  3710 
  3711 * arith(_tac)
  3712 
  3713  - Produces a counter example if it cannot prove a goal.
  3714    Note that the counter example may be spurious if the goal is not a formula
  3715    of quantifier-free linear arithmetic.
  3716    In ProofGeneral the counter example appears in the trace buffer.
  3717 
  3718  - Knows about div k and mod k where k is a numeral of type nat or int.
  3719 
  3720  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3721    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3722    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3723 
  3724 * simp's arithmetic capabilities have been enhanced a bit: it now
  3725 takes ~= in premises into account (by performing a case split);
  3726 
  3727 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3728 are distributed over a sum of terms;
  3729 
  3730 * New tactic "trans_tac" and method "trans" instantiate
  3731 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3732 "<=", "<" and "=").
  3733 
  3734 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3735 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3736 
  3737 * 'typedef' command has new option "open" to suppress the set
  3738 definition;
  3739 
  3740 * functions Min and Max on finite sets have been introduced (theory
  3741 Finite_Set);
  3742 
  3743 * attribute [symmetric] now works for relations as well; it turns
  3744 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3745 
  3746 * induct over a !!-quantified statement (say !!x1..xn):
  3747   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3748 
  3749 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3750 %x. None. Warning: empty_def now refers to the previously hidden definition
  3751 of the empty set.
  3752 
  3753 * Algebra: formalization of classical algebra.  Intended as base for
  3754 any algebraic development in Isabelle.  Currently covers group theory
  3755 (up to Sylow's theorem) and ring theory (Universal Property of
  3756 Univariate Polynomials).  Contributions welcome;
  3757 
  3758 * GroupTheory: deleted, since its material has been moved to Algebra;
  3759 
  3760 * Complex: new directory of the complex numbers with numeric constants,
  3761 nonstandard complex numbers, and some complex analysis, standard and
  3762 nonstandard (Jacques Fleuriot);
  3763 
  3764 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3765 
  3766 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3767 Fleuriot);
  3768 
  3769 * Real/HahnBanach: updated and adapted to locales;
  3770 
  3771 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3772 Gray and Kramer);
  3773 
  3774 * UNITY: added the Meier-Sanders theory of progress sets;
  3775 
  3776 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3777 as abstract algorithms, instantiated to the JVM;
  3778 
  3779 * Bali: Java source language formalization. Type system, operational
  3780 semantics, axiomatic semantics. Supported language features:
  3781 classes, interfaces, objects,virtual methods, static methods,
  3782 static/instance fields, arrays, access modifiers, definite
  3783 assignment, exceptions.
  3784 
  3785 
  3786 *** ZF ***
  3787 
  3788 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3789 universe, etc.);
  3790 
  3791 * Main ZF: virtually all theories converted to new-style format;
  3792 
  3793 
  3794 *** ML ***
  3795 
  3796 * Pure: Tactic.prove provides sane interface for internal proofs;
  3797 omits the infamous "standard" operation, so this is more appropriate
  3798 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3799 
  3800 * Pure: improved error reporting of simprocs;
  3801 
  3802 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3803 up simprocs;
  3804 
  3805 
  3806 *** Document preparation ***
  3807 
  3808 * uses \par instead of \\ for line breaks in theory text. This may
  3809 shift some page breaks in large documents. To get the old behaviour
  3810 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3811 
  3812 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3813 other packages
  3814 
  3815 * \<euro> now needs package babel/greek instead of marvosym (which
  3816 broke \Rightarrow)
  3817 
  3818 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3819 textcomp package)
  3820 
  3821 
  3822 
  3823 New in Isabelle2002 (March 2002)
  3824 --------------------------------
  3825 
  3826 *** Document preparation ***
  3827 
  3828 * greatly simplified document preparation setup, including more
  3829 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3830 instructive isatool mkdir; users should basically be able to get
  3831 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3832 users may run a separate document processing stage manually like this:
  3833 "isatool usedir -D output HOL Test && isatool document Test/output";
  3834 
  3835 * theory dependency graph may now be incorporated into documents;
  3836 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3837 with \includegraphics of LaTeX;
  3838 
  3839 * proper spacing of consecutive markup elements, especially text
  3840 blocks after section headings;
  3841 
  3842 * support bold style (for single symbols only), input syntax is like
  3843 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3844 
  3845 * \<bullet> is now output as bold \cdot by default, which looks much
  3846 better in printed text;
  3847 
  3848 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3849 note that these symbols are currently unavailable in Proof General /
  3850 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3851 
  3852 * isatool latex no longer depends on changed TEXINPUTS, instead
  3853 isatool document copies the Isabelle style files to the target
  3854 location;
  3855 
  3856 
  3857 *** Isar ***
  3858 
  3859 * Pure/Provers: improved proof by cases and induction;
  3860   - 'case' command admits impromptu naming of parameters (such as
  3861     "case (Suc n)");
  3862   - 'induct' method divinates rule instantiation from the inductive
  3863     claim; no longer requires excessive ?P bindings for proper
  3864     instantiation of cases;
  3865   - 'induct' method properly enumerates all possibilities of set/type
  3866     rules; as a consequence facts may be also passed through *type*
  3867     rules without further ado;
  3868   - 'induct' method now derives symbolic cases from the *rulified*
  3869     rule (before it used to rulify cases stemming from the internal
  3870     atomized version); this means that the context of a non-atomic
  3871     statement becomes is included in the hypothesis, avoiding the
  3872     slightly cumbersome show "PROP ?case" form;
  3873   - 'induct' may now use elim-style induction rules without chaining
  3874     facts, using ``missing'' premises from the goal state; this allows
  3875     rules stemming from inductive sets to be applied in unstructured
  3876     scripts, while still benefitting from proper handling of non-atomic
  3877     statements; NB: major inductive premises need to be put first, all
  3878     the rest of the goal is passed through the induction;
  3879   - 'induct' proper support for mutual induction involving non-atomic
  3880     rule statements (uses the new concept of simultaneous goals, see
  3881     below);
  3882   - append all possible rule selections, but only use the first
  3883     success (no backtracking);
  3884   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3885   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3886   - added 'print_induct_rules' (covered by help item in recent Proof
  3887     General versions);
  3888   - moved induct/cases attributes to Pure, methods to Provers;
  3889   - generic method setup instantiated for FOL and HOL;
  3890 
  3891 * Pure: support multiple simultaneous goal statements, for example
  3892 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3893 meta-level mechanism, this acts as if several individual goals had
  3894 been stated separately; in particular common proof methods need to be
  3895 repeated in order to cover all claims; note that a single elimination
  3896 step is *not* sufficient to establish the two conjunctions, so this
  3897 fails:
  3898 
  3899   assume "A & B" then have A and B ..   (*".." fails*)
  3900 
  3901 better use "obtain" in situations as above; alternative refer to
  3902 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3903 
  3904 * Pure: proper integration with ``locales''; unlike the original
  3905 version by Florian Kammller, Isar locales package high-level proof
  3906 contexts rather than raw logical ones (e.g. we admit to include
  3907 attributes everywhere); operations on locales include merge and
  3908 rename; support for implicit arguments (``structures''); simultaneous
  3909 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3910 some examples;
  3911 
  3912 * Pure: the following commands have been ``localized'', supporting a
  3913 target locale specification "(in name)": 'lemma', 'theorem',
  3914 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3915 stored both within the locale and at the theory level (exported and
  3916 qualified by the locale name);
  3917 
  3918 * Pure: theory goals may now be specified in ``long'' form, with
  3919 ad-hoc contexts consisting of arbitrary locale elements. for example
  3920 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3921 definitions may be given, too); the result is a meta-level rule with
  3922 the context elements being discharged in the obvious way;
  3923 
  3924 * Pure: new proof command 'using' allows to augment currently used
  3925 facts after a goal statement ('using' is syntactically analogous to
  3926 'apply', but acts on the goal's facts only); this allows chained facts
  3927 to be separated into parts given before and after a claim, as in
  3928 ``from a and b have C using d and e <proof>'';
  3929 
  3930 * Pure: renamed "antecedent" case to "rule_context";
  3931 
  3932 * Pure: new 'judgment' command records explicit information about the
  3933 object-logic embedding (used by several tools internally); no longer
  3934 use hard-wired "Trueprop";
  3935 
  3936 * Pure: added 'corollary' command;
  3937 
  3938 * Pure: fixed 'token_translation' command;
  3939 
  3940 * Pure: removed obsolete 'exported' attribute;
  3941 
  3942 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3943 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3944 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3945 
  3946 * Pure: method 'atomize' presents local goal premises as object-level
  3947 statements (atomic meta-level propositions); setup controlled via
  3948 rewrite rules declarations of 'atomize' attribute; example
  3949 application: 'induct' method with proper rule statements in improper
  3950 proof *scripts*;
  3951 
  3952 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3953 now consider the syntactic context of assumptions, giving a better
  3954 chance to get type-inference of the arguments right (this is
  3955 especially important for locales);
  3956 
  3957 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3958 mode;
  3959 
  3960 * Pure/obtain: the formal conclusion "thesis", being marked as
  3961 ``internal'', may no longer be reference directly in the text;
  3962 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3963 situations;
  3964 
  3965 * Pure: generic 'sym' attribute which declares a rule both as pure
  3966 'elim?' and for the 'symmetric' operation;
  3967 
  3968 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3969 text; the fixed correlation with particular command syntax has been
  3970 discontinued;
  3971 
  3972 * Pure: new method 'rules' is particularly well-suited for proof
  3973 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3974 but often produces more compact proof terms with less detours;
  3975 
  3976 * Pure/Provers/classical: simplified integration with pure rule
  3977 attributes and methods; the classical "intro?/elim?/dest?"
  3978 declarations coincide with the pure ones; the "rule" method no longer
  3979 includes classically swapped intros; "intro" and "elim" methods no
  3980 longer pick rules from the context; also got rid of ML declarations
  3981 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3982 INCOMPATIBILITY;
  3983 
  3984 * Provers/classical: attribute 'swapped' produces classical inversions
  3985 of introduction rules;
  3986 
  3987 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3988 rules instead of full simplifier context; 'iff' attribute handles
  3989 conditional rules;
  3990 
  3991 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3992 
  3993 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3994 "(permissive)" option to recover old behavior;
  3995 
  3996 * HOL: 'inductive' no longer features separate (collective) attributes
  3997 for 'intros' (was found too confusing);
  3998 
  3999 * HOL: properly declared induction rules less_induct and
  4000 wf_induct_rule;
  4001 
  4002 
  4003 *** HOL ***
  4004 
  4005 * HOL: moved over to sane numeral syntax; the new policy is as
  4006 follows:
  4007 
  4008   - 0 and 1 are polymorphic constants, which are defined on any
  4009   numeric type (nat, int, real etc.);
  4010 
  4011   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4012   binary representation internally;
  4013 
  4014   - type nat has special constructor Suc, and generally prefers Suc 0
  4015   over 1::nat and Suc (Suc 0) over 2::nat;
  4016 
  4017 This change may cause significant problems of INCOMPATIBILITY; here
  4018 are some hints on converting existing sources:
  4019 
  4020   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4021   entities, so expressions involving "-" (unary or binary minus) need
  4022   to be spaced properly;
  4023 
  4024   - existing occurrences of "1" may need to be constraint "1::nat" or
  4025   even replaced by Suc 0; similar for old "2";
  4026 
  4027   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4028 
  4029   - remove all special provisions on numerals in proofs;
  4030 
  4031 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4032 representation (depends on bin_arith_simps in the default context);
  4033 
  4034 * HOL: symbolic syntax for x^2 (numeral 2);
  4035 
  4036 * HOL: the class of all HOL types is now called "type" rather than
  4037 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4038 in axclass/classes, instance/arities, and (usually rare) occurrences
  4039 in typings (of consts etc.); internally the class is called
  4040 "HOL.type", ML programs should refer to HOLogic.typeS;
  4041 
  4042 * HOL/record package improvements:
  4043   - new derived operations "fields" to build a partial record section,
  4044     "extend" to promote a fixed record to a record scheme, and
  4045     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4046     declared as simp by default;
  4047   - shared operations ("more", "fields", etc.) now need to be always
  4048     qualified) --- potential INCOMPATIBILITY;
  4049   - removed "make_scheme" operations (use "make" with "extend") --
  4050     INCOMPATIBILITY;
  4051   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4052   - provides cases/induct rules for use with corresponding Isar
  4053     methods (for concrete records, record schemes, concrete more
  4054     parts, and schematic more parts -- in that order);
  4055   - internal definitions directly based on a light-weight abstract
  4056     theory of product types over typedef rather than datatype;
  4057 
  4058 * HOL: generic code generator for generating executable ML code from
  4059 specifications; specific support for HOL constructs such as inductive
  4060 datatypes and sets, as well as recursive functions; can be invoked
  4061 via 'generate_code' theory section;
  4062 
  4063 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4064 
  4065 * HOL: consolidated and renamed several theories.  In particular:
  4066         Ord.thy has been absorbed into HOL.thy
  4067         String.thy has been absorbed into List.thy
  4068 
  4069 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4070 (beware of argument permutation!);
  4071 
  4072 * HOL: linorder_less_split superseded by linorder_cases;
  4073 
  4074 * HOL/List: "nodups" renamed to "distinct";
  4075 
  4076 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4077 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4078   - Ex_def has changed, now need to use some_eq_ex
  4079 
  4080 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4081 in this (rare) case use:
  4082 
  4083   delSWrapper "split_all_tac"
  4084   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4085 
  4086 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4087 MAY FAIL;
  4088 
  4089 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4090 Isabelle's type classes, ^ on functions and relations has too general
  4091 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4092 necessary to attach explicit type constraints;
  4093 
  4094 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4095 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4096 renamed accordingly (eg "compI" -> "rel_compI").
  4097 
  4098 * HOL: syntax translations now work properly with numerals and records
  4099 expressions;
  4100 
  4101 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4102 of "lam" -- INCOMPATIBILITY;
  4103 
  4104 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4105 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4106 renamed "Product_Type.unit";
  4107 
  4108 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4109 
  4110 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4111 the "cases" method);
  4112 
  4113 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4114 Florian Kammller);
  4115 
  4116 * HOL/IMP: updated and converted to new-style theory format; several
  4117 parts turned into readable document, with proper Isar proof texts and
  4118 some explanations (by Gerwin Klein);
  4119 
  4120 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4121 
  4122 * HOL-Hyperreal is now a logic image;
  4123 
  4124 
  4125 *** HOLCF ***
  4126 
  4127 * Isar: consts/constdefs supports mixfix syntax for continuous
  4128 operations;
  4129 
  4130 * Isar: domain package adapted to new-style theory format, e.g. see
  4131 HOLCF/ex/Dnat.thy;
  4132 
  4133 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4134 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4135 lift.induct_tac, always use UU instead of Undef;
  4136 
  4137 * HOLCF/IMP: updated and converted to new-style theory;
  4138 
  4139 
  4140 *** ZF ***
  4141 
  4142 * Isar: proper integration of logic-specific tools and packages,
  4143 including theory commands '(co)inductive', '(co)datatype',
  4144 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4145 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4146 
  4147 * theory Main no longer includes AC; for the Axiom of Choice, base
  4148 your theory on Main_ZFC;
  4149 
  4150 * the integer library now covers quotients and remainders, with many
  4151 laws relating division to addition, multiplication, etc.;
  4152 
  4153 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4154 typeless version of the formalism;
  4155 
  4156 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4157 format;
  4158 
  4159 * ZF/Induct: new directory for examples of inductive definitions,
  4160 including theory Multiset for multiset orderings; converted to
  4161 new-style theory format;
  4162 
  4163 * ZF: many new theorems about lists, ordinals, etc.;
  4164 
  4165 
  4166 *** General ***
  4167 
  4168 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4169 variable proof controls level of detail: 0 = no proofs (only oracle
  4170 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4171 also ref manual for further ML interfaces;
  4172 
  4173 * Pure/axclass: removed obsolete ML interface
  4174 goal_subclass/goal_arity;
  4175 
  4176 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4177 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4178 separate tokens, so expressions involving minus need to be spaced
  4179 properly;
  4180 
  4181 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4182 rather than "infixl" or "infixr";
  4183 
  4184 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4185 sort constraint specifications in type inference; e.g. "x::_::foo"
  4186 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4187 type variable);
  4188 
  4189 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4190 control output of nested => (types); the default behavior is
  4191 "type_brackets";
  4192 
  4193 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4194 tokens into AST constants;
  4195 
  4196 * Pure/syntax: prefer later declarations of translations and print
  4197 translation functions; potential INCOMPATIBILITY: need to reverse
  4198 multiple declarations for same syntax element constant;
  4199 
  4200 * Pure/show_hyps reset by default (in accordance to existing Isar
  4201 practice);
  4202 
  4203 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4204 addSafter;
  4205 
  4206 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4207 as well;
  4208 
  4209 * system: tested support for MacOS X; should be able to get Isabelle +
  4210 Proof General to work in a plain Terminal after installing Poly/ML
  4211 (e.g. from the Isabelle distribution area) and GNU bash alone
  4212 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4213 support requires further installations, e.g. from
  4214 http://fink.sourceforge.net/);
  4215 
  4216 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4217 
  4218 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4219 of 40 MB), cf. ML_OPTIONS;
  4220 
  4221 * system: Proof General keywords specification is now part of the
  4222 Isabelle distribution (see etc/isar-keywords.el);
  4223 
  4224 * system: support for persistent Proof General sessions (refrain from
  4225 outdating all loaded theories on startup); user may create writable
  4226 logic images like this: ``isabelle -q HOL Test'';
  4227 
  4228 * system: smart selection of Isabelle process versus Isabelle
  4229 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4230 run both "isabelle" and "Isabelle" even if file names are badly
  4231 damaged (executable inspects the case of the first letter of its own
  4232 name); added separate "isabelle-process" and "isabelle-interface";
  4233 
  4234 * system: refrain from any attempt at filtering input streams; no
  4235 longer support ``8bit'' encoding of old isabelle font, instead proper
  4236 iso-latin characters may now be used; the related isatools
  4237 "symbolinput" and "nonascii" have disappeared as well;
  4238 
  4239 * system: removed old "xterm" interface (the print modes "xterm" and
  4240 "xterm_color" are still available for direct use in a suitable
  4241 terminal);
  4242 
  4243 
  4244 
  4245 New in Isabelle99-2 (February 2001)
  4246 -----------------------------------
  4247 
  4248 *** Overview of INCOMPATIBILITIES ***
  4249 
  4250 * HOL: please note that theories in the Library and elsewhere often use the
  4251 new-style (Isar) format; to refer to their theorems in an ML script you must
  4252 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4253 
  4254 * HOL: inductive package no longer splits induction rule aggressively,
  4255 but only as far as specified by the introductions given; the old
  4256 format may be recovered via ML function complete_split_rule or attribute
  4257 'split_rule (complete)';
  4258 
  4259 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4260 gfp_Tarski to gfp_unfold;
  4261 
  4262 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4263 
  4264 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4265 relation); infix "^^" has been renamed "``"; infix "``" has been
  4266 renamed "`"; "univalent" has been renamed "single_valued";
  4267 
  4268 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4269 operation;
  4270 
  4271 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4272 
  4273 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4274 
  4275 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4276 consequence, it is no longer monotonic wrt. the local goal context
  4277 (which is now passed through the inductive cases);
  4278 
  4279 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4280 \<gg> to \<ggreater>;
  4281 
  4282 
  4283 *** Document preparation ***
  4284 
  4285 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4286 available: are "it" for near math-mode best-style output, "sl" for
  4287 slanted text style, and "tt" for plain type-writer; if no
  4288 \isabellestyle command is given, output is according to slanted
  4289 type-writer);
  4290 
  4291 * support sub/super scripts (for single symbols only), input syntax is
  4292 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4293 
  4294 * some more standard symbols; see Appendix A of the system manual for
  4295 the complete list of symbols defined in isabellesym.sty;
  4296 
  4297 * improved isabelle style files; more abstract symbol implementation
  4298 (should now use \isamath{...} and \isatext{...} in custom symbol
  4299 definitions);
  4300 
  4301 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4302 state; Note that presentation of goal states does not conform to
  4303 actual human-readable proof documents.  Please do not include goal
  4304 states into document output unless you really know what you are doing!
  4305 
  4306 * proper indentation of antiquoted output with proportional LaTeX
  4307 fonts;
  4308 
  4309 * no_document ML operator temporarily disables LaTeX document
  4310 generation;
  4311 
  4312 * isatool unsymbolize tunes sources for plain ASCII communication;
  4313 
  4314 
  4315 *** Isar ***
  4316 
  4317 * Pure: Isar now suffers initial goal statements to contain unbound
  4318 schematic variables (this does not conform to actual readable proof
  4319 documents, due to unpredictable outcome and non-compositional proof
  4320 checking); users who know what they are doing may use schematic goals
  4321 for Prolog-style synthesis of proven results;
  4322 
  4323 * Pure: assumption method (an implicit finishing) now handles actual
  4324 rules as well;
  4325 
  4326 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4327 initial goal, declare "that" only as Pure intro (only for single
  4328 steps); the "that" rule assumption may now be involved in implicit
  4329 finishing, thus ".." becomes a feasible for trivial obtains;
  4330 
  4331 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4332 instance proofs may be performed by "..";
  4333 
  4334 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4335 statements as well;
  4336 
  4337 * Pure: more robust selection of calculational rules;
  4338 
  4339 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4340 rule (as well as the assumption rule);
  4341 
  4342 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4343 lemmas, using the graph browser tool;
  4344 
  4345 * Pure: predict failure of "show" in interactive mode;
  4346 
  4347 * Pure: 'thms_containing' now takes actual terms as arguments;
  4348 
  4349 * HOL: improved method 'induct' --- now handles non-atomic goals
  4350 (potential INCOMPATIBILITY); tuned error handling;
  4351 
  4352 * HOL: cases and induct rules now provide explicit hints about the
  4353 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4354 any remaining facts are inserted into the goal verbatim;
  4355 
  4356 * HOL: local contexts (aka cases) may now contain term bindings as
  4357 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4358 the result to be shown in each case;
  4359 
  4360 * HOL: added 'recdef_tc' command;
  4361 
  4362 * isatool convert assists in eliminating legacy ML scripts;
  4363 
  4364 
  4365 *** HOL ***
  4366 
  4367 * HOL/Library: a collection of generic theories to be used together
  4368 with main HOL; the theory loader path already includes this directory
  4369 by default; the following existing theories have been moved here:
  4370 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4371 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4372 
  4373 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4374 modelling and verification task performed in Isabelle/HOL +
  4375 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4376 
  4377 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4378 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4379 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4380 'domain', this makes the theory consistent with mathematical
  4381 literature;
  4382 
  4383 * HOL basics: added overloaded operations "inverse" and "divide"
  4384 (infix "/"), syntax for generic "abs" operation, generic summation
  4385 operator \<Sum>;
  4386 
  4387 * HOL/typedef: simplified package, provide more useful rules (see also
  4388 HOL/subset.thy);
  4389 
  4390 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4391 now expressed as a proper nested rule (old-style tactic scripts may
  4392 require atomize_strip_tac to cope with non-atomic premises);
  4393 
  4394 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4395 to "split_conv" (old name still available for compatibility);
  4396 
  4397 * HOL: improved concrete syntax for strings (e.g. allows translation
  4398 rules with string literals);
  4399 
  4400 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4401  and Fleuriot's mechanization of analysis, including the transcendental
  4402  functions for the reals;
  4403 
  4404 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4405 
  4406 
  4407 *** CTT ***
  4408 
  4409 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4410 "lam" is displayed as TWO lambda-symbols
  4411 
  4412 * CTT: theory Main now available, containing everything (that is, Bool
  4413 and Arith);
  4414 
  4415 
  4416 *** General ***
  4417 
  4418 * Pure: the Simplifier has been implemented properly as a derived rule
  4419 outside of the actual kernel (at last!); the overall performance
  4420 penalty in practical applications is about 50%, while reliability of
  4421 the Isabelle inference kernel has been greatly improved;
  4422 
  4423 * print modes "brackets" and "no_brackets" control output of nested =>
  4424 (types) and ==> (props); the default behaviour is "brackets";
  4425 
  4426 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4427 as assumptions as well;
  4428 
  4429 * system: support Poly/ML 4.0;
  4430 
  4431 * system: isatool install handles KDE version 1 or 2;
  4432 
  4433 
  4434 
  4435 New in Isabelle99-1 (October 2000)
  4436 ----------------------------------
  4437 
  4438 *** Overview of INCOMPATIBILITIES ***
  4439 
  4440 * HOL: simplification of natural numbers is much changed; to partly
  4441 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4442 issue the following ML commands:
  4443 
  4444   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4445   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4446 
  4447 * HOL: simplification no longer dives into case-expressions; this is
  4448 controlled by "t.weak_case_cong" for each datatype t;
  4449 
  4450 * HOL: nat_less_induct renamed to less_induct;
  4451 
  4452 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4453 fixsome to patch .thy and .ML sources automatically;
  4454 
  4455   select_equality  -> some_equality
  4456   select_eq_Ex     -> some_eq_ex
  4457   selectI2EX       -> someI2_ex
  4458   selectI2         -> someI2
  4459   selectI          -> someI
  4460   select1_equality -> some1_equality
  4461   Eps_sym_eq       -> some_sym_eq_trivial
  4462   Eps_eq           -> some_eq_trivial
  4463 
  4464 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4465 
  4466 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4467 instead);
  4468 
  4469 * HOL: the recursion equations generated by 'recdef' are now called
  4470 f.simps instead of f.rules;
  4471 
  4472 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4473 
  4474 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4475 sometimes be needed;
  4476 
  4477 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4478 
  4479 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4480 
  4481 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4482 product is now "<*>" instead of "Times"; the lexicographic product is
  4483 now "<*lex*>" instead of "**";
  4484 
  4485 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4486 of main HOL, but was unused); better use HOL's datatype package;
  4487 
  4488 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4489 the old syntax may be recovered as follows:
  4490 
  4491   syntax (symbols)
  4492     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4493       (infixl "\\<oplus>" 100)
  4494 
  4495 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4496 
  4497 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4498 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4499 internally;
  4500 
  4501 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4502 changed from A/r to A//r;
  4503 
  4504 * ZF: new treatment of arithmetic (nat & int) may break some old
  4505 proofs;
  4506 
  4507 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4508 rulify -> rule_format, elimify -> elim_format, ...);
  4509 
  4510 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4511 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4512 should have to change intro!! to intro? only); replaced "delrule" by
  4513 "rule del";
  4514 
  4515 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4516 
  4517 * Provers: strengthened force_tac by using new first_best_tac;
  4518 
  4519 * LaTeX document preparation: several changes of isabelle.sty (see
  4520 lib/texinputs);
  4521 
  4522 
  4523 *** Document preparation ***
  4524 
  4525 * formal comments (text blocks etc.) in new-style theories may now
  4526 contain antiquotations of thm/prop/term/typ/text to be presented
  4527 according to latex print mode; concrete syntax is like this:
  4528 @{term[show_types] "f(x) = a + x"};
  4529 
  4530 * isatool mkdir provides easy setup of Isabelle session directories,
  4531 including proper document sources;
  4532 
  4533 * generated LaTeX sources are now deleted after successful run
  4534 (isatool document -c); may retain a copy somewhere else via -D option
  4535 of isatool usedir;
  4536 
  4537 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4538 style files, achieving self-contained LaTeX sources and simplifying
  4539 LaTeX debugging;
  4540 
  4541 * old-style theories now produce (crude) LaTeX output as well;
  4542 
  4543 * browser info session directories are now self-contained (may be put
  4544 on WWW server seperately); improved graphs of nested sessions; removed
  4545 graph for 'all sessions';
  4546 
  4547 * several improvements in isabelle style files; \isabellestyle{it}
  4548 produces fake math mode output; \isamarkupheader is now \section by
  4549 default; see lib/texinputs/isabelle.sty etc.;
  4550 
  4551 
  4552 *** Isar ***
  4553 
  4554 * Isar/Pure: local results and corresponding term bindings are now
  4555 subject to Hindley-Milner polymorphism (similar to ML); this
  4556 accommodates incremental type-inference very nicely;
  4557 
  4558 * Isar/Pure: new derived language element 'obtain' supports
  4559 generalized existence reasoning;
  4560 
  4561 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4562 support accumulation of results, without applying any rules yet;
  4563 useful to collect intermediate results without explicit name
  4564 references, and for use with transitivity rules with more than 2
  4565 premises;
  4566 
  4567 * Isar/Pure: scalable support for case-analysis type proofs: new
  4568 'case' language element refers to local contexts symbolically, as
  4569 produced by certain proof methods; internally, case names are attached
  4570 to theorems as "tags";
  4571 
  4572 * Isar/Pure: theory command 'hide' removes declarations from
  4573 class/type/const name spaces;
  4574 
  4575 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4576 indicate potential overloading;
  4577 
  4578 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4579 
  4580 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4581 "{a,b,c}" instead of {a,b,c};
  4582 
  4583 * Isar/Pure now provides its own version of intro/elim/dest
  4584 attributes; useful for building new logics, but beware of confusion
  4585 with the version in Provers/classical;
  4586 
  4587 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4588 case name 'antecedent';
  4589 
  4590 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4591 to the current context is now done automatically);
  4592 
  4593 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4594 for definining proof methods in ML;
  4595 
  4596 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4597 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4598 most cases, one should have to change intro!! to intro? only);
  4599 replaced "delrule" by "rule del";
  4600 
  4601 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4602 'symmetric' attribute (the latter supercedes [RS sym]);
  4603 
  4604 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4605 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4606 well (including splits);
  4607 
  4608 * Isar/Provers: Simplifier and Classical methods now support all kind
  4609 of modifiers used in the past, including 'cong', 'iff', etc.
  4610 
  4611 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4612 of Simplifier and Classical reasoner);
  4613 
  4614 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4615 now support named cases; major packages (inductive, datatype, primrec,
  4616 recdef) support case names and properly name parameters;
  4617 
  4618 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4619 monotonicity conditions are extracted to be proven at end of
  4620 calculations;
  4621 
  4622 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4623 method anyway;
  4624 
  4625 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4626 split_if split_if_asm; datatype package provides theorems foo.splits =
  4627 foo.split foo.split_asm for each datatype;
  4628 
  4629 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4630 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4631 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4632 use "(cases (simplified))" method in proper proof texts);
  4633 
  4634 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4635 
  4636 * Isar: names of theorems etc. may be natural numbers as well;
  4637 
  4638 * Isar: 'pr' command: optional arguments for goals_limit and
  4639 ProofContext.prems_limit; no longer prints theory contexts, but only
  4640 proof states;
  4641 
  4642 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4643 additional print modes to be specified; e.g. "pr(latex)" will print
  4644 proof state according to the Isabelle LaTeX style;
  4645 
  4646 * Isar: improved support for emulating tactic scripts, including proof
  4647 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4648 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4649 (for HOL datatypes);
  4650 
  4651 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4652 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4653 'proof method scripts' have to be in depth-first order;
  4654 
  4655 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4656 
  4657 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4658 should instead use individual commands for printing items
  4659 (print_commands, print_methods etc.);
  4660 
  4661 * Isar: added 'nothing' --- the empty list of theorems;
  4662 
  4663 
  4664 *** HOL ***
  4665 
  4666 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4667 corresponding virtual machine and a specification of its bytecode
  4668 verifier and a lightweight bytecode verifier, including proofs of
  4669 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4670 Cornelia Pusch (see also the homepage of project Bali at
  4671 http://isabelle.in.tum.de/Bali/);
  4672 
  4673 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4674 Clemens Ballarin;
  4675 
  4676 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4677 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4678 Rasmussen;
  4679 
  4680 * HOL/Lattice: fundamental concepts of lattice theory and order
  4681 structures, including duals, properties of bounds versus algebraic
  4682 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4683 Theorem for complete lattices etc.; may also serve as a demonstration
  4684 for abstract algebraic reasoning using axiomatic type classes, and
  4685 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4686 
  4687 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4688 von Oheimb;
  4689 
  4690 * HOL/IMPP: extension of IMP with local variables and mutually
  4691 recursive procedures, by David von Oheimb;
  4692 
  4693 * HOL/Lambda: converted into new-style theory and document;
  4694 
  4695 * HOL/ex/Multiquote: example of multiple nested quotations and
  4696 anti-quotations -- basically a generalized version of de-Bruijn
  4697 representation; very useful in avoiding lifting of operations;
  4698 
  4699 * HOL/record: added general record equality rule to simpset; fixed
  4700 select-update simplification procedure to handle extended records as
  4701 well; admit "r" as field name;
  4702 
  4703 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4704 other numeric types and also as the identity of groups, rings, etc.;
  4705 
  4706 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4707 Types nat and int belong to this axclass;
  4708 
  4709 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4710    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4711    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4712   two terms #m*u and #n*u are replaced by #(m+n)*u
  4713     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4714   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4715     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4716 
  4717 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4718 powerful prover for predicate logic but knows nothing of clasets; see
  4719 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4720 
  4721 * HOL: new version of "case_tac" subsumes both boolean case split and
  4722 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4723 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4724 
  4725 * HOL: simplification no longer dives into case-expressions: only the
  4726 selector expression is simplified, but not the remaining arms; to
  4727 enable full simplification of case-expressions for datatype t, you may
  4728 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4729 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4730 
  4731 * HOL/recdef: the recursion equations generated by 'recdef' for
  4732 function 'f' are now called f.simps instead of f.rules; if all
  4733 termination conditions are proved automatically, these simplification
  4734 rules are added to the simpset, as in primrec; rules may be named
  4735 individually as well, resulting in a separate list of theorems for
  4736 each equation;
  4737 
  4738 * HOL/While is a new theory that provides a while-combinator. It
  4739 permits the definition of tail-recursive functions without the
  4740 provision of a termination measure. The latter is necessary once the
  4741 invariant proof rule for while is applied.
  4742 
  4743 * HOL: new (overloaded) notation for the set of elements below/above
  4744 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4745 
  4746 * HOL: theorems impI, allI, ballI bound as "strip";
  4747 
  4748 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4749 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4750 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4751 
  4752 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4753 
  4754 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4755 main HOL, but was unused);
  4756 
  4757 * HOL: fewer consts declared as global (e.g. have to refer to
  4758 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4759 
  4760 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4761 in case of overlap with user translations (e.g. judgements over
  4762 tuples); (note that the underlying logical represenation is still
  4763 bogus);
  4764 
  4765 
  4766 *** ZF ***
  4767 
  4768 * ZF: simplification automatically cancels common terms in arithmetic
  4769 expressions over nat and int;
  4770 
  4771 * ZF: new treatment of nat to minimize type-checking: all operators
  4772 coerce their operands to a natural number using the function natify,
  4773 making the algebraic laws unconditional;
  4774 
  4775 * ZF: as above, for int: operators coerce their operands to an integer
  4776 using the function intify;
  4777 
  4778 * ZF: the integer library now contains many of the usual laws for the
  4779 orderings, including $<=, and monotonicity laws for $+ and $*;
  4780 
  4781 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4782 simplification;
  4783 
  4784 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4785 to the simplifier and classical reasoner simultaneously;
  4786 
  4787 
  4788 *** General ***
  4789 
  4790 * Provers: blast_tac now handles actual object-logic rules as
  4791 assumptions; note that auto_tac uses blast_tac internally as well;
  4792 
  4793 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4794 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4795 
  4796 * Provers: delrules now handles destruct rules as well (no longer need
  4797 explicit make_elim);
  4798 
  4799 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4800   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4801 use instead the strong form,
  4802   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4803 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4804 from destruct-rules;
  4805 
  4806 * Provers: Simplifier.easy_setup provides a fast path to basic
  4807 Simplifier setup for new object-logics;
  4808 
  4809 * Pure: AST translation rules no longer require constant head on LHS;
  4810 
  4811 * Pure: improved name spaces: ambiguous output is qualified; support
  4812 for hiding of names;
  4813 
  4814 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4815 XSYMBOL_HOME; no longer need to do manual configuration in most
  4816 situations;
  4817 
  4818 * system: compression of ML heaps images may now be controlled via -c
  4819 option of isabelle and isatool usedir (currently only observed by
  4820 Poly/ML);
  4821 
  4822 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4823 useful for remote X11);
  4824 
  4825 * system: provide TAGS file for Isabelle sources;
  4826 
  4827 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4828 order;
  4829 
  4830 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4831 timing flag supersedes proof_timing and Toplevel.trace;
  4832 
  4833 * ML: new combinators |>> and |>>> for incremental transformations
  4834 with secondary results (e.g. certain theory extensions):
  4835 
  4836 * ML: PureThy.add_defs gets additional argument to indicate potential
  4837 overloading (usually false);
  4838 
  4839 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4840 results;
  4841 
  4842 
  4843 
  4844 New in Isabelle99 (October 1999)
  4845 --------------------------------
  4846 
  4847 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4848 
  4849 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4850 are no longer simplified.  (This allows the simplifier to unfold recursive
  4851 functional programs.)  To restore the old behaviour, declare
  4852 
  4853     Delcongs [if_weak_cong];
  4854 
  4855 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4856 complement;
  4857 
  4858 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4859 
  4860 * HOL/datatype: mutual_induct_tac no longer exists --
  4861   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4862 
  4863 * HOL/typedef: fixed type inference for representing set; type
  4864 arguments now have to occur explicitly on the rhs as type constraints;
  4865 
  4866 * ZF: The con_defs part of an inductive definition may no longer refer
  4867 to constants declared in the same theory;
  4868 
  4869 * HOL, ZF: the function mk_cases, generated by the inductive
  4870 definition package, has lost an argument.  To simplify its result, it
  4871 uses the default simpset instead of a supplied list of theorems.
  4872 
  4873 * HOL/List: the constructors of type list are now Nil and Cons;
  4874 
  4875 * Simplifier: the type of the infix ML functions
  4876         setSSolver addSSolver setSolver addSolver
  4877 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4878 for packaging solvers. A solver is created via
  4879         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4880 where the string argument is only a comment.
  4881 
  4882 
  4883 *** Proof tools ***
  4884 
  4885 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4886 decision procedure for linear arithmetic. Currently it is used for
  4887 types `nat', `int', and `real' in HOL (see below); it can, should and
  4888 will be instantiated for other types and logics as well.
  4889 
  4890 * The simplifier now accepts rewrite rules with flexible heads, eg
  4891      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4892   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4893   matching.
  4894 
  4895 
  4896 *** General ***
  4897 
  4898 * New Isabelle/Isar subsystem provides an alternative to traditional
  4899 tactical theorem proving; together with the ProofGeneral/isar user
  4900 interface it offers an interactive environment for developing human
  4901 readable proof documents (Isar == Intelligible semi-automated
  4902 reasoning); for further information see isatool doc isar-ref,
  4903 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4904 
  4905 * improved and simplified presentation of theories: better HTML markup
  4906 (including colors), graph views in several sizes; isatool usedir now
  4907 provides a proper interface for user theories (via -P option); actual
  4908 document preparation based on (PDF)LaTeX is available as well (for
  4909 new-style theories only); see isatool doc system for more information;
  4910 
  4911 * native support for Proof General, both for classic Isabelle and
  4912 Isabelle/Isar;
  4913 
  4914 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4915 using the graph browser tool;
  4916 
  4917 * Isabelle manuals now also available as PDF;
  4918 
  4919 * theory loader rewritten from scratch (may not be fully
  4920 bug-compatible); old loadpath variable has been replaced by show_path,
  4921 add_path, del_path, reset_path functions; new operations such as
  4922 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4923 isatool doc ref);
  4924 
  4925 * improved isatool install: option -k creates KDE application icon,
  4926 option -p DIR installs standalone binaries;
  4927 
  4928 * added ML_PLATFORM setting (useful for cross-platform installations);
  4929 more robust handling of platform specific ML images for SML/NJ;
  4930 
  4931 * the settings environment is now statically scoped, i.e. it is never
  4932 created again in sub-processes invoked from isabelle, isatool, or
  4933 Isabelle;
  4934 
  4935 * path element specification '~~' refers to '$ISABELLE_HOME';
  4936 
  4937 * in locales, the "assumes" and "defines" parts may be omitted if
  4938 empty;
  4939 
  4940 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4941 long arrows);
  4942 
  4943 * new print_mode "HTML";
  4944 
  4945 * new flag show_tags controls display of tags of theorems (which are
  4946 basically just comments that may be attached by some tools);
  4947 
  4948 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4949 mode and goal output format:
  4950 
  4951 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4952 244c244
  4953 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4954 ---
  4955 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4956 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4957 181c181
  4958 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4959 ---
  4960 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4961 
  4962 * function bind_thms stores lists of theorems (cf. bind_thm);
  4963 
  4964 * new shorthand tactics ftac, eatac, datac, fatac;
  4965 
  4966 * qed (and friends) now accept "" as result name; in that case the
  4967 theorem is not stored, but proper checks and presentation of the
  4968 result still apply;
  4969 
  4970 * theorem database now also indexes constants "Trueprop", "all",
  4971 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4972 
  4973 
  4974 *** HOL ***
  4975 
  4976 ** HOL arithmetic **
  4977 
  4978 * There are now decision procedures for linear arithmetic over nat and
  4979 int:
  4980 
  4981 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4982 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4983 are treated as atomic; subformulae not involving type `nat' or `int'
  4984 are ignored; quantified subformulae are ignored unless they are
  4985 positive universal or negative existential. The tactic has to be
  4986 invoked by hand and can be a little bit slow. In particular, the
  4987 running time is exponential in the number of occurrences of `min' and
  4988 `max', and `-' on `nat'.
  4989 
  4990 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4991 (negated) (in)equalities among the premises and the conclusion into
  4992 account (i.e. no compound formulae) and does not know about `min' and
  4993 `max', and `-' on `nat'. It is fast and is used automatically by the
  4994 simplifier.
  4995 
  4996 NB: At the moment, these decision procedures do not cope with mixed
  4997 nat/int formulae where the two parts interact, such as `m < n ==>
  4998 int(m) < int(n)'.
  4999 
  5000 * HOL/Numeral provides a generic theory of numerals (encoded
  5001 efficiently as bit strings); setup for types nat/int/real is in place;
  5002 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5003 int, existing theories and proof scripts may require a few additional
  5004 type constraints;
  5005 
  5006 * integer division and remainder can now be performed on constant
  5007 arguments;
  5008 
  5009 * many properties of integer multiplication, division and remainder
  5010 are now available;
  5011 
  5012 * An interface to the Stanford Validity Checker (SVC) is available through the
  5013 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5014 are proved automatically.  SVC must be installed separately, and its results
  5015 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5016 invocation of the underlying oracle).  For SVC see
  5017   http://verify.stanford.edu/SVC
  5018 
  5019 * IsaMakefile: the HOL-Real target now builds an actual image;
  5020 
  5021 
  5022 ** HOL misc **
  5023 
  5024 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5025 (in Isabelle/Isar) -- by Gertrud Bauer;
  5026 
  5027 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5028 analysis for assembly languages with subtypes;
  5029 
  5030 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5031 -- avoids syntactic ambiguities and treats state, transition, and
  5032 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5033 changed syntax and (many) tactics;
  5034 
  5035 * HOL/inductive: Now also handles more general introduction rules such
  5036   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5037   theorems are now maintained within the theory (maintained via the
  5038   "mono" attribute);
  5039 
  5040 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5041   (using function types) such as
  5042 
  5043   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5044 
  5045 * HOL/record: record_simproc (part of the default simpset) takes care
  5046 of selectors applied to updated records; record_split_tac is no longer
  5047 part of the default claset; update_defs may now be removed from the
  5048 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5049 
  5050   claset_ref () := claset() addSWrapper record_split_wrapper;
  5051   Delsimprocs [record_simproc]
  5052 
  5053 * HOL/typedef: fixed type inference for representing set; type
  5054 arguments now have to occur explicitly on the rhs as type constraints;
  5055 
  5056 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5057 names rather than an ML expression;
  5058 
  5059 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5060 supplied later.  Program schemes can be defined, such as
  5061     "While B C s = (if B s then While B C (C s) else s)"
  5062 where the well-founded relation can be chosen after B and C have been given.
  5063 
  5064 * HOL/List: the constructors of type list are now Nil and Cons;
  5065 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5066 course, ML tools referring to List.list.op # etc. have to be adapted;
  5067 
  5068 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5069 disabled by default; run isabelle with option -m HOL to get back to
  5070 the original Gordon/HOL-style output;
  5071 
  5072 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5073 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5074 
  5075 * HOL basic syntax simplified (more orthogonal): all variants of
  5076 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5077 Eps operator is provided as well: "SOME x. P[x]";
  5078 
  5079 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5080 
  5081 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5082 thus available for user theories;
  5083 
  5084 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5085 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5086 time;
  5087 
  5088 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5089 several times and then mp;
  5090 
  5091 
  5092 *** LK ***
  5093 
  5094 * the notation <<...>> is now available as a notation for sequences of
  5095 formulas;
  5096 
  5097 * the simplifier is now installed
  5098 
  5099 * the axiom system has been generalized (thanks to Soren Heilmann)
  5100 
  5101 * the classical reasoner now has a default rule database
  5102 
  5103 
  5104 *** ZF ***
  5105 
  5106 * new primrec section allows primitive recursive functions to be given
  5107 directly (as in HOL) over datatypes and the natural numbers;
  5108 
  5109 * new tactics induct_tac and exhaust_tac for induction (or case
  5110 analysis) over datatypes and the natural numbers;
  5111 
  5112 * the datatype declaration of type T now defines the recursor T_rec;
  5113 
  5114 * simplification automatically does freeness reasoning for datatype
  5115 constructors;
  5116 
  5117 * automatic type-inference, with AddTCs command to insert new
  5118 type-checking rules;
  5119 
  5120 * datatype introduction rules are now added as Safe Introduction rules
  5121 to the claset;
  5122 
  5123 * the syntax "if P then x else y" is now available in addition to
  5124 if(P,x,y);
  5125 
  5126 
  5127 *** Internal programming interfaces ***
  5128 
  5129 * tuned simplifier trace output; new flag debug_simp;
  5130 
  5131 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5132 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5133 
  5134 * AxClass.axclass_tac lost the theory argument;
  5135 
  5136 * tuned current_goals_markers semantics: begin / end goal avoids
  5137 printing empty lines;
  5138 
  5139 * removed prs and prs_fn hook, which was broken because it did not
  5140 include \n in its semantics, forcing writeln to add one
  5141 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5142 string -> unit if you really want to output text without newline;
  5143 
  5144 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5145 plain output, interface builders may have to enable 'isabelle_font'
  5146 mode to get Isabelle font glyphs as before;
  5147 
  5148 * refined token_translation interface; INCOMPATIBILITY: output length
  5149 now of type real instead of int;
  5150 
  5151 * theory loader actions may be traced via new ThyInfo.add_hook
  5152 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5153 your own database of information attached to *whole* theories -- as
  5154 opposed to intra-theory data slots offered via TheoryDataFun;
  5155 
  5156 * proper handling of dangling sort hypotheses (at last!);
  5157 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5158 extra sort hypotheses that can be witnessed from the type signature;
  5159 the force_strip_shyps flag is gone, any remaining shyps are simply
  5160 left in the theorem (with a warning issued by strip_shyps_warning);
  5161 
  5162 
  5163 
  5164 New in Isabelle98-1 (October 1998)
  5165 ----------------------------------
  5166 
  5167 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5168 
  5169 * several changes of automated proof tools;
  5170 
  5171 * HOL: major changes to the inductive and datatype packages, including
  5172 some minor incompatibilities of theory syntax;
  5173 
  5174 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5175 called `inj_on';
  5176 
  5177 * HOL: removed duplicate thms in Arith:
  5178   less_imp_add_less  should be replaced by  trans_less_add1
  5179   le_imp_add_le      should be replaced by  trans_le_add1
  5180 
  5181 * HOL: unary minus is now overloaded (new type constraints may be
  5182 required);
  5183 
  5184 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5185 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5186 now taken as an integer constant.
  5187 
  5188 * Pure: ML function 'theory_of' renamed to 'theory';
  5189 
  5190 
  5191 *** Proof tools ***
  5192 
  5193 * Simplifier:
  5194   1. Asm_full_simp_tac is now more aggressive.
  5195      1. It will sometimes reorient premises if that increases their power to
  5196         simplify.
  5197      2. It does no longer proceed strictly from left to right but may also
  5198         rotate premises to achieve further simplification.
  5199      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5200      old Asm_full_simp_tac in that it does not rotate premises.
  5201   2. The simplifier now knows a little bit about nat-arithmetic.
  5202 
  5203 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5204 allows for selected deletion of wrappers, by introduction of names for
  5205 wrapper functionals.  This implies that addbefore, addSbefore,
  5206 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5207 and that adding two tactics with the same name overwrites the first
  5208 one (emitting a warning).
  5209   type wrapper = (int -> tactic) -> (int -> tactic)
  5210   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5211   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5212   delWrapper, delSWrapper: claset *  string            -> claset
  5213   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5214 
  5215 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5216 semantics; addbefore now affects only the unsafe part of step_tac
  5217 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5218 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5219 by Force_tac;
  5220 
  5221 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5222 compWrapper; added safe wrapper (and access functions for it);
  5223 
  5224 * HOL/split_all_tac is now much faster and fails if there is nothing
  5225 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5226 and the names of the automatically generated variables have changed.
  5227 split_all_tac has moved within claset() from unsafe wrappers to safe
  5228 wrappers, which means that !!-bound variables are split much more
  5229 aggressively, and safe_tac and clarify_tac now split such variables.
  5230 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5231 Note: the same holds for record_split_tac, which does the job of
  5232 split_all_tac for record fields.
  5233 
  5234 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5235 permanently to the default simpset using Addsplits just like
  5236 Addsimps. They can be removed via Delsplits just like
  5237 Delsimps. Lower-case versions are also available.
  5238 
  5239 * HOL/Simplifier: The rule split_if is now part of the default
  5240 simpset. This means that the simplifier will eliminate all occurrences
  5241 of if-then-else in the conclusion of a goal. To prevent this, you can
  5242 either remove split_if completely from the default simpset by
  5243 `Delsplits [split_if]' or remove it in a specific call of the
  5244 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5245 other case splitting rules to/from the default simpset: every datatype
  5246 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5247 t is the name of the datatype).
  5248 
  5249 * Classical reasoner / Simplifier combination: new force_tac (and
  5250 derivatives Force_tac, force) combines rewriting and classical
  5251 reasoning (and whatever other tools) similarly to auto_tac, but is
  5252 aimed to solve the given subgoal completely.
  5253 
  5254 
  5255 *** General ***
  5256 
  5257 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5258 and `goalw': the theory is no longer needed as an explicit argument -
  5259 the current theory context is used; assumptions are no longer returned
  5260 at the ML-level unless one of them starts with ==> or !!; it is
  5261 recommended to convert to these new commands using isatool fixgoal
  5262 (backup your sources first!);
  5263 
  5264 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5265 the current theory context, and 'theory' to lookup stored theories;
  5266 
  5267 * new theory section 'locale' for declaring constants, assumptions and
  5268 definitions that have local scope;
  5269 
  5270 * new theory section 'nonterminals' for purely syntactic types;
  5271 
  5272 * new theory section 'setup' for generic ML setup functions
  5273 (e.g. package initialization);
  5274 
  5275 * the distribution now includes Isabelle icons: see
  5276 lib/logo/isabelle-{small,tiny}.xpm;
  5277 
  5278 * isatool install - install binaries with absolute references to
  5279 ISABELLE_HOME/bin;
  5280 
  5281 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5282 
  5283 * print mode 'emacs' reserved for Isamode;
  5284 
  5285 * support multiple print (ast) translations per constant name;
  5286 
  5287 * theorems involving oracles are now printed with a suffixed [!];
  5288 
  5289 
  5290 *** HOL ***
  5291 
  5292 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5293 
  5294 * HOL/inductive package reorganized and improved: now supports mutual
  5295 definitions such as
  5296 
  5297   inductive EVEN ODD
  5298     intrs
  5299       null "0 : EVEN"
  5300       oddI "n : EVEN ==> Suc n : ODD"
  5301       evenI "n : ODD ==> Suc n : EVEN"
  5302 
  5303 new theorem list "elims" contains an elimination rule for each of the
  5304 recursive sets; inductive definitions now handle disjunctive premises
  5305 correctly (also ZF);
  5306 
  5307 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5308 "mutual_induct" no longer exists - the induction rule is always
  5309 contained in "induct";
  5310 
  5311 
  5312 * HOL/datatype package re-implemented and greatly improved: now
  5313 supports mutually recursive datatypes such as
  5314 
  5315   datatype
  5316     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5317             | SUM ('a aexp) ('a aexp)
  5318             | DIFF ('a aexp) ('a aexp)
  5319             | NUM 'a
  5320   and
  5321     'a bexp = LESS ('a aexp) ('a aexp)
  5322             | AND ('a bexp) ('a bexp)
  5323             | OR ('a bexp) ('a bexp)
  5324 
  5325 as well as indirectly recursive datatypes such as
  5326 
  5327   datatype
  5328     ('a, 'b) term = Var 'a
  5329                   | App 'b ((('a, 'b) term) list)
  5330 
  5331 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5332 induction on mutually / indirectly recursive datatypes.
  5333 
  5334 Primrec equations are now stored in theory and can be accessed via
  5335 <function_name>.simps.
  5336 
  5337 INCOMPATIBILITIES:
  5338 
  5339   - Theories using datatypes must now have theory Datatype as an
  5340     ancestor.
  5341   - The specific <typename>.induct_tac no longer exists - use the
  5342     generic induct_tac instead.
  5343   - natE has been renamed to nat.exhaust - use exhaust_tac
  5344     instead of res_inst_tac ... natE. Note that the variable
  5345     names in nat.exhaust differ from the names in natE, this
  5346     may cause some "fragile" proofs to fail.
  5347   - The theorems split_<typename>_case and split_<typename>_case_asm
  5348     have been renamed to <typename>.split and <typename>.split_asm.
  5349   - Since default sorts of type variables are now handled correctly,
  5350     some datatype definitions may have to be annotated with explicit
  5351     sort constraints.
  5352   - Primrec definitions no longer require function name and type
  5353     of recursive argument.
  5354 
  5355 Consider using isatool fixdatatype to adapt your theories and proof
  5356 scripts to the new package (backup your sources first!).
  5357 
  5358 
  5359 * HOL/record package: considerably improved implementation; now
  5360 includes concrete syntax for record types, terms, updates; theorems
  5361 for surjective pairing and splitting !!-bound record variables; proof
  5362 support is as follows:
  5363 
  5364   1) standard conversions (selectors or updates applied to record
  5365 constructor terms) are part of the standard simpset;
  5366 
  5367   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5368 made part of standard simpset and claset via addIffs;
  5369 
  5370   3) a tactic for record field splitting (record_split_tac) is part of
  5371 the standard claset (addSWrapper);
  5372 
  5373 To get a better idea about these rules you may retrieve them via
  5374 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5375 the name of your record type.
  5376 
  5377 The split tactic 3) conceptually simplifies by the following rule:
  5378 
  5379   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5380 
  5381 Thus any record variable that is bound by meta-all will automatically
  5382 blow up into some record constructor term, consequently the
  5383 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5384 solve record problems automatically.
  5385 
  5386 
  5387 * reorganized the main HOL image: HOL/Integ and String loaded by
  5388 default; theory Main includes everything;
  5389 
  5390 * automatic simplification of integer sums and comparisons, using cancellation;
  5391 
  5392 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5393 
  5394 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5395 
  5396 * many new identities for unions, intersections, set difference, etc.;
  5397 
  5398 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5399 called split_if, split_split, split_sum_case and split_nat_case (to go
  5400 with add/delsplits);
  5401 
  5402 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5403 (?x::unit) = (); this is made part of the default simpset, which COULD
  5404 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5405 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5406 unit_abs_eta_conv is added in order to counter the effect of
  5407 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5408 %u.f();
  5409 
  5410 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5411 makes more sense);
  5412 
  5413 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5414   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5415   disjointness reasoning but breaking a few old proofs.
  5416 
  5417 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5418 to 'converse' from 'inverse' (for compatibility with ZF and some
  5419 literature);
  5420 
  5421 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5422 the well-founded relation;
  5423 
  5424 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5425     Compl A.  The "Compl" syntax remains available as input syntax for this
  5426     release ONLY.
  5427 
  5428 * HOL/Update: new theory of function updates:
  5429     f(a:=b) == %x. if x=a then b else f x
  5430 may also be iterated as in f(a:=b,c:=d,...);
  5431 
  5432 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5433 
  5434 * HOL/List:
  5435   - new function list_update written xs[i:=v] that updates the i-th
  5436     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5437   - new function `upt' written [i..j(] which generates the list
  5438     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5439     bound write [i..j], which is a shorthand for [i..j+1(].
  5440   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5441 
  5442 * HOL/Arith:
  5443   - removed 'pred' (predecessor) function;
  5444   - generalized some theorems about n-1;
  5445   - many new laws about "div" and "mod";
  5446   - new laws about greatest common divisors (see theory ex/Primes);
  5447 
  5448 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5449 instead of "inverse";
  5450 
  5451 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5452   of the multiset ordering;
  5453 
  5454 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5455   (not included by default);
  5456 
  5457 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5458 
  5459 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5460   programs, i.e. different program variables may have different types.
  5461 
  5462 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5463   [previously, this check worked only if the rewrite rule was unconditional]
  5464   Now rew can involve either definitions or equalities (either == or =).
  5465 
  5466 
  5467 *** ZF ***
  5468 
  5469 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5470   only the theorems proved on ZF.ML;
  5471 
  5472 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5473   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5474   disjointness reasoning but breaking a few old proofs.
  5475 
  5476 * ZF/Update: new theory of function updates
  5477     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5478   may also be iterated as in f(a:=b,c:=d,...);
  5479 
  5480 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5481 
  5482 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5483   [previously, this check worked only if the rewrite rule was unconditional]
  5484   Now rew can involve either definitions or equalities (either == or =).
  5485 
  5486 * case_tac provided for compatibility with HOL
  5487     (like the old excluded_middle_tac, but with subgoals swapped)
  5488 
  5489 
  5490 *** Internal programming interfaces ***
  5491 
  5492 * Pure: several new basic modules made available for general use, see
  5493 also src/Pure/README;
  5494 
  5495 * improved the theory data mechanism to support encapsulation (data
  5496 kind name replaced by private Object.kind, acting as authorization
  5497 key); new type-safe user interface via functor TheoryDataFun; generic
  5498 print_data function becomes basically useless;
  5499 
  5500 * removed global_names compatibility flag -- all theory declarations
  5501 are qualified by default;
  5502 
  5503 * module Pure/Syntax now offers quote / antiquote translation
  5504 functions (useful for Hoare logic etc. with implicit dependencies);
  5505 see HOL/ex/Antiquote for an example use;
  5506 
  5507 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5508 cterm -> thm;
  5509 
  5510 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5511 subgoal;
  5512 
  5513 * Display.print_goals function moved to Locale.print_goals;
  5514 
  5515 * standard print function for goals supports current_goals_markers
  5516 variable for marking begin of proof, end of proof, start of goal; the
  5517 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5518 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5519 for example;
  5520 
  5521 
  5522 
  5523 New in Isabelle98 (January 1998)
  5524 --------------------------------
  5525 
  5526 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5527 
  5528 * changed lexical syntax of terms / types: dots made part of long
  5529 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5530 
  5531 * simpset (and claset) reference variable replaced by functions
  5532 simpset / simpset_ref;
  5533 
  5534 * no longer supports theory aliases (via merge) and non-trivial
  5535 implicit merge of thms' signatures;
  5536 
  5537 * most internal names of constants changed due to qualified names;
  5538 
  5539 * changed Pure/Sequence interface (see Pure/seq.ML);
  5540 
  5541 
  5542 *** General Changes ***
  5543 
  5544 * hierachically structured name spaces (for consts, types, axms, thms
  5545 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5546 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5547 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5548 long_names for fully qualified output names; NOTE: ML programs
  5549 (special tactics, packages etc.) referring to internal names may have
  5550 to be adapted to cope with fully qualified names; in case of severe
  5551 backward campatibility problems try setting 'global_names' at compile
  5552 time to have enrything declared within a flat name space; one may also
  5553 fine tune name declarations in theories via the 'global' and 'local'
  5554 section;
  5555 
  5556 * reimplemented the implicit simpset and claset using the new anytype
  5557 data filed in signatures; references simpset:simpset ref etc. are
  5558 replaced by functions simpset:unit->simpset and
  5559 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5560 to patch your ML files accordingly;
  5561 
  5562 * HTML output now includes theory graph data for display with Java
  5563 applet or isatool browser; data generated automatically via isatool
  5564 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5565 
  5566 * defs may now be conditional; improved rewrite_goals_tac to handle
  5567 conditional equations;
  5568 
  5569 * defs now admits additional type arguments, using TYPE('a) syntax;
  5570 
  5571 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5572 creates a new theory node; implicit merge of thms' signatures is
  5573 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5574 transfer:theory->thm->thm in (rare) cases;
  5575 
  5576 * improved handling of draft signatures / theories; draft thms (and
  5577 ctyps, cterms) are automatically promoted to real ones;
  5578 
  5579 * slightly changed interfaces for oracles: admit many per theory, named
  5580 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5581 
  5582 * print_goals: optional output of const types (set show_consts and
  5583 show_types);
  5584 
  5585 * improved output of warnings (###) and errors (***);
  5586 
  5587 * subgoal_tac displays a warning if the new subgoal has type variables;
  5588 
  5589 * removed old README and Makefiles;
  5590 
  5591 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5592 
  5593 * removed obsolete init_pps and init_database;
  5594 
  5595 * deleted the obsolete tactical STATE, which was declared by
  5596     fun STATE tacfun st = tacfun st st;
  5597 
  5598 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5599 (which abbreviates $HOME);
  5600 
  5601 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5602 use isatool fixseq to adapt your ML programs (this works for fully
  5603 qualified references to the Sequence structure only!);
  5604 
  5605 * use_thy no longer requires writable current directory; it always
  5606 reloads .ML *and* .thy file, if either one is out of date;
  5607 
  5608 
  5609 *** Classical Reasoner ***
  5610 
  5611 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5612 tactics that use classical reasoning to simplify a subgoal without
  5613 splitting it into several subgoals;
  5614 
  5615 * Safe_tac: like safe_tac but uses the default claset;
  5616 
  5617 
  5618 *** Simplifier ***
  5619 
  5620 * added simplification meta rules:
  5621     (asm_)(full_)simplify: simpset -> thm -> thm;
  5622 
  5623 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5624 logics (again);
  5625 
  5626 * added prems argument to simplification procedures;
  5627 
  5628 * HOL, FOL, ZF: added infix function `addsplits':
  5629   instead of `<simpset> setloop (split_tac <thms>)'
  5630   you can simply write `<simpset> addsplits <thms>'
  5631 
  5632 
  5633 *** Syntax ***
  5634 
  5635 * TYPE('a) syntax for type reflection terms;
  5636 
  5637 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5638 
  5639 * pretty printer: changed order of mixfix annotation preference (again!);
  5640 
  5641 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5642 
  5643 
  5644 *** HOL ***
  5645 
  5646 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5647   with `addloop' of the simplifier to faciliate case splitting in premises.
  5648 
  5649 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5650 
  5651 * HOL/Auth: new protocol proofs including some for the Internet
  5652   protocol TLS;
  5653 
  5654 * HOL/Map: new theory of `maps' a la VDM;
  5655 
  5656 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5657 cancelling out common nat summands from =, <, <= (in)equalities, or
  5658 differences; simplification procedures nat_cancel_factor for
  5659 cancelling common factor from =, <, <= (in)equalities over natural
  5660 sums; nat_cancel contains both kinds of procedures, it is installed by
  5661 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5662 
  5663 * HOL/simplifier: terms of the form
  5664   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5665   are rewritten to
  5666   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5667   and those of the form
  5668   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5669   are rewritten to
  5670   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5671 
  5672 * HOL/datatype
  5673   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5674 
  5675   P(t_case f1 ... fn x) =
  5676      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5677         ...
  5678        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5679      )
  5680 
  5681   and a theorem `split_t_case_asm' of the form
  5682 
  5683   P(t_case f1 ... fn x) =
  5684     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5685         ...
  5686        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5687      )
  5688   which can be added to a simpset via `addsplits'. The existing theorems
  5689   expand_list_case and expand_option_case have been renamed to
  5690   split_list_case and split_option_case.
  5691 
  5692 * HOL/Arithmetic:
  5693   - `pred n' is automatically converted to `n-1'.
  5694     Users are strongly encouraged not to use `pred' any longer,
  5695     because it will disappear altogether at some point.
  5696   - Users are strongly encouraged to write "0 < n" rather than
  5697     "n ~= 0". Theorems and proof tools have been modified towards this
  5698     `standard'.
  5699 
  5700 * HOL/Lists:
  5701   the function "set_of_list" has been renamed "set" (and its theorems too);
  5702   the function "nth" now takes its arguments in the reverse order and
  5703   has acquired the infix notation "!" as in "xs!n".
  5704 
  5705 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5706 
  5707 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5708   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5709 
  5710 * HOL/record: extensible records with schematic structural subtyping
  5711 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5712 still lacks various theorems and concrete record syntax;
  5713 
  5714 
  5715 *** HOLCF ***
  5716 
  5717 * removed "axioms" and "generated by" sections;
  5718 
  5719 * replaced "ops" section by extended "consts" section, which is capable of
  5720   handling the continuous function space "->" directly;
  5721 
  5722 * domain package:
  5723   . proves theorems immediately and stores them in the theory,
  5724   . creates hierachical name space,
  5725   . now uses normal mixfix annotations (instead of cinfix...),
  5726   . minor changes to some names and values (for consistency),
  5727   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5728   . separator between mutual domain defs: changed "," to "and",
  5729   . improved handling of sort constraints;  now they have to
  5730     appear on the left-hand side of the equations only;
  5731 
  5732 * fixed LAM <x,y,zs>.b syntax;
  5733 
  5734 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5735 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5736 
  5737 
  5738 *** FOL and ZF ***
  5739 
  5740 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5741   with `addloop' of the simplifier to faciliate case splitting in premises.
  5742 
  5743 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5744 in HOL, they strip ALL and --> from proved theorems;
  5745 
  5746 
  5747 
  5748 New in Isabelle94-8 (May 1997)
  5749 ------------------------------
  5750 
  5751 *** General Changes ***
  5752 
  5753 * new utilities to build / run / maintain Isabelle etc. (in parts
  5754 still somewhat experimental); old Makefiles etc. still functional;
  5755 
  5756 * new 'Isabelle System Manual';
  5757 
  5758 * INSTALL text, together with ./configure and ./build scripts;
  5759 
  5760 * reimplemented type inference for greater efficiency, better error
  5761 messages and clean internal interface;
  5762 
  5763 * prlim command for dealing with lots of subgoals (an easier way of
  5764 setting goals_limit);
  5765 
  5766 
  5767 *** Syntax ***
  5768 
  5769 * supports alternative (named) syntax tables (parser and pretty
  5770 printer); internal interface is provided by add_modesyntax(_i);
  5771 
  5772 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5773 be used in conjunction with the Isabelle symbol font; uses the
  5774 "symbols" syntax table;
  5775 
  5776 * added token_translation interface (may translate name tokens in
  5777 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5778 the current print_mode); IMPORTANT: user print translation functions
  5779 are responsible for marking newly introduced bounds
  5780 (Syntax.mark_boundT);
  5781 
  5782 * token translations for modes "xterm" and "xterm_color" that display
  5783 names in bold, underline etc. or colors (which requires a color
  5784 version of xterm);
  5785 
  5786 * infixes may now be declared with names independent of their syntax;
  5787 
  5788 * added typed_print_translation (like print_translation, but may
  5789 access type of constant);
  5790 
  5791 
  5792 *** Classical Reasoner ***
  5793 
  5794 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5795 some limitations.  Blast_tac...
  5796   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5797   + ignores elimination rules that don't have the correct format
  5798         (the conclusion MUST be a formula variable)
  5799   + ignores types, which can make HOL proofs fail
  5800   + rules must not require higher-order unification, e.g. apply_type in ZF
  5801     [message "Function Var's argument not a bound variable" relates to this]
  5802   + its proof strategy is more general but can actually be slower
  5803 
  5804 * substitution with equality assumptions no longer permutes other
  5805 assumptions;
  5806 
  5807 * minor changes in semantics of addafter (now called addaltern); renamed
  5808 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5809 (and access functions for it);
  5810 
  5811 * improved combination of classical reasoner and simplifier:
  5812   + functions for handling clasimpsets
  5813   + improvement of addss: now the simplifier is called _after_ the
  5814     safe steps.
  5815   + safe variant of addss called addSss: uses safe simplifications
  5816     _during_ the safe steps. It is more complete as it allows multiple
  5817     instantiations of unknowns (e.g. with slow_tac).
  5818 
  5819 *** Simplifier ***
  5820 
  5821 * added interface for simplification procedures (functions that
  5822 produce *proven* rewrite rules on the fly, depending on current
  5823 redex);
  5824 
  5825 * ordering on terms as parameter (used for ordered rewriting);
  5826 
  5827 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5828 
  5829 * the solver is now split into a safe and an unsafe part.
  5830 This should be invisible for the normal user, except that the
  5831 functions setsolver and addsolver have been renamed to setSolver and
  5832 addSolver; added safe_asm_full_simp_tac;
  5833 
  5834 
  5835 *** HOL ***
  5836 
  5837 * a generic induction tactic `induct_tac' which works for all datatypes and
  5838 also for type `nat';
  5839 
  5840 * a generic case distinction tactic `exhaust_tac' which works for all
  5841 datatypes and also for type `nat';
  5842 
  5843 * each datatype comes with a function `size';
  5844 
  5845 * patterns in case expressions allow tuple patterns as arguments to
  5846 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5847 
  5848 * primrec now also works with type nat;
  5849 
  5850 * recdef: a new declaration form, allows general recursive functions to be
  5851 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5852 
  5853 * the constant for negation has been renamed from "not" to "Not" to
  5854 harmonize with FOL, ZF, LK, etc.;
  5855 
  5856 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5857 infinite lists;
  5858 
  5859 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5860 
  5861 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5862 problems in commutative rings, using axiomatic type classes for + and *;
  5863 
  5864 * more examples in HOL/MiniML and HOL/Auth;
  5865 
  5866 * more default rewrite rules for quantifiers, union/intersection;
  5867 
  5868 * a new constant `arbitrary == @x.False';
  5869 
  5870 * HOLCF/IOA replaces old HOL/IOA;
  5871 
  5872 * HOLCF changes: derived all rules and arities
  5873   + axiomatic type classes instead of classes
  5874   + typedef instead of faking type definitions
  5875   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5876   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5877   + eliminated the types void, one, tr
  5878   + use unit lift and bool lift (with translations) instead of one and tr
  5879   + eliminated blift from Lift3.thy (use Def instead of blift)
  5880   all eliminated rules are derived as theorems --> no visible changes ;
  5881 
  5882 
  5883 *** ZF ***
  5884 
  5885 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5886 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5887 as ZF_cs addSIs [equalityI];
  5888 
  5889 
  5890 
  5891 New in Isabelle94-7 (November 96)
  5892 ---------------------------------
  5893 
  5894 * allowing negative levels (as offsets) in prlev and choplev;
  5895 
  5896 * super-linear speedup for large simplifications;
  5897 
  5898 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5899 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5900 FAIL); can suppress it using the command Delsimps (ex_simps @
  5901 all_simps); De Morgan laws are also now included, by default;
  5902 
  5903 * improved printing of ==>  :  ~:
  5904 
  5905 * new object-logic "Sequents" adds linear logic, while replacing LK
  5906 and Modal (thanks to Sara Kalvala);
  5907 
  5908 * HOL/Auth: correctness proofs for authentication protocols;
  5909 
  5910 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5911 examples on HOL/Auth);
  5912 
  5913 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5914 the rewriter and classical reasoner simultaneously;
  5915 
  5916 * function uresult no longer returns theorems in "standard" format;
  5917 regain previous version by: val uresult = standard o uresult;
  5918 
  5919 
  5920 
  5921 New in Isabelle94-6
  5922 -------------------
  5923 
  5924 * oracles -- these establish an interface between Isabelle and trusted
  5925 external reasoners, which may deliver results as theorems;
  5926 
  5927 * proof objects (in particular record all uses of oracles);
  5928 
  5929 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5930 
  5931 * "constdefs" section in theory files;
  5932 
  5933 * "primrec" section (HOL) no longer requires names;
  5934 
  5935 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5936 
  5937 
  5938 
  5939 New in Isabelle94-5
  5940 -------------------
  5941 
  5942 * reduced space requirements;
  5943 
  5944 * automatic HTML generation from theories;
  5945 
  5946 * theory files no longer require "..." (quotes) around most types;
  5947 
  5948 * new examples, including two proofs of the Church-Rosser theorem;
  5949 
  5950 * non-curried (1994) version of HOL is no longer distributed;
  5951 
  5952 
  5953 
  5954 New in Isabelle94-4
  5955 -------------------
  5956 
  5957 * greatly reduced space requirements;
  5958 
  5959 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5960 
  5961 * searchable theorem database (see the section "Retrieving theorems" on
  5962 page 8 of the Reference Manual);
  5963 
  5964 * new examples, including Grabczewski's monumental case study of the
  5965 Axiom of Choice;
  5966 
  5967 * The previous version of HOL renamed to Old_HOL;
  5968 
  5969 * The new version of HOL (previously called CHOL) uses a curried syntax
  5970 for functions.  Application looks like f a b instead of f(a,b);
  5971 
  5972 * Mutually recursive inductive definitions finally work in HOL;
  5973 
  5974 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5975 translates to the operator "split";
  5976 
  5977 
  5978 
  5979 New in Isabelle94-3
  5980 -------------------
  5981 
  5982 * new infix operator, addss, allowing the classical reasoner to
  5983 perform simplification at each step of its search.  Example:
  5984         fast_tac (cs addss ss)
  5985 
  5986 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5987 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5988 look like (a,b) instead of <a,b>;
  5989 
  5990 * PLEASE NOTE: CHOL will eventually replace HOL!
  5991 
  5992 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5993 It translates to the operator "split".  A new theory of integers is available;
  5994 
  5995 * In ZF, integer numerals now denote two's-complement binary integers.
  5996 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5997 
  5998 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5999 of the Axiom of Choice;
  6000 
  6001 
  6002 
  6003 New in Isabelle94-2
  6004 -------------------
  6005 
  6006 * Significantly faster resolution;
  6007 
  6008 * the different sections in a .thy file can now be mixed and repeated
  6009 freely;
  6010 
  6011 * Database of theorems for FOL, HOL and ZF.  New
  6012 commands including qed, qed_goal and bind_thm store theorems in the database.
  6013 
  6014 * Simple database queries: return a named theorem (get_thm) or all theorems of
  6015 a given theory (thms_of), or find out what theory a theorem was proved in
  6016 (theory_of_thm);
  6017 
  6018 * Bugs fixed in the inductive definition and datatype packages;
  6019 
  6020 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  6021 and HOL_dup_cs obsolete;
  6022 
  6023 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  6024 have been removed;
  6025 
  6026 * Simpler definition of function space in ZF;
  6027 
  6028 * new results about cardinal and ordinal arithmetic in ZF;
  6029 
  6030 * 'subtype' facility in HOL for introducing new types as subsets of existing
  6031 types;
  6032 
  6033 :mode=text:wrap=hard:maxLineLen=72: