NEWS
author kleing
Fri Feb 13 07:59:30 2009 +1100 (2009-02-13)
changeset 29883 14841d4c808e
parent 29862 d203e9d4675b
child 30044 f9182081d6c6
permissions -rw-r--r--
added find_consts to NEWS and CONTRIBUTORS
     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 * New find_theorems criterion "solves" matching theorems that
   187 directly solve the current goal. Try "find_theorems solves".
   188 
   189 * Added an auto solve option, which can be enabled through the
   190 ProofGeneral Isabelle settings menu (disabled by default).
   191  
   192 When enabled, find_theorems solves is called whenever a new lemma is
   193 stated. Any theorems that could solve the lemma directly are listed
   194 underneath the goal.
   195 
   196 * New command find_consts searches for constants based on type and name 
   197 patterns, e.g.
   198 
   199     find_consts "_ => bool"
   200 
   201 By default, matching is against subtypes, but it may be restricted to the
   202 whole type. Searching by name is possible. Multiple queries are conjunctive
   203 and queries may be negated by prefixing them with a hyphen:
   204 
   205     find_consts strict: "_ => bool" name: "Int" -"int => int"
   206 
   207 
   208 *** Document preparation ***
   209 
   210 * Antiquotation @{lemma} now imitates a regular terminal proof,
   211 demanding keyword 'by' and supporting the full method expression
   212 syntax just like the Isar command 'by'.
   213 
   214 
   215 *** HOL ***
   216 
   217 * Auxiliary class "itself" has disappeared -- classes without any parameter
   218 are treated as expected by the 'class' command.
   219 
   220 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   221 
   222 * Common decision procedures (Cooper, MIR, Ferrack, Approximation, Dense_Linear_Order)
   223 now in directory HOL/Decision_Procs.
   224 
   225 * Theory HOL/Decisioin_Procs/Approximation.thy provides the new proof method
   226 "approximation".  It proves formulas on real values by using interval arithmetic.
   227 In the formulas are also the transcendental functions sin, cos, tan, atan, ln,
   228 exp and the constant pi are allowed.  For examples see HOL/ex/ApproximationEx.thy.
   229 
   230 * Theory "Reflection" now resides in HOL/Library.
   231 
   232 * Entry point to Word library now simply named "Word".  INCOMPATIBILITY.
   233 
   234 * Made source layout more coherent with logical distribution
   235 structure:
   236 
   237     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   238     src/HOL/Library/Code_Message.thy ~> src/HOL/
   239     src/HOL/Library/GCD.thy ~> src/HOL/
   240     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   241     src/HOL/Library/Parity.thy ~> src/HOL/
   242     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   243     src/HOL/Real/ContNotDenum.thy ~> src/HOL/
   244     src/HOL/Real/Lubs.thy ~> src/HOL/
   245     src/HOL/Real/PReal.thy ~> src/HOL/
   246     src/HOL/Real/Rational.thy ~> src/HOL/
   247     src/HOL/Real/RComplete.thy ~> src/HOL/
   248     src/HOL/Real/RealDef.thy ~> src/HOL/
   249     src/HOL/Real/RealPow.thy ~> src/HOL/
   250     src/HOL/Real/Real.thy ~> src/HOL/
   251     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   252     src/HOL/Complex/Complex.thy ~> src/HOL/
   253     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/
   254     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/
   255     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   256     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   257     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   258     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   259     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   260     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   261     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   262     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   263     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   264     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   265     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   266     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   267     src/HOL/Real/Float ~> src/HOL/Library/
   268     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   269     src/HOL/Real/RealVector.thy ~> src/HOL/
   270 
   271     src/HOL/arith_data.ML ~> src/HOL/Tools
   272     src/HOL/hologic.ML ~> src/HOL/Tools
   273     src/HOL/simpdata.ML ~> src/HOL/Tools
   274     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   275     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   276     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   277     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   278     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   279     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   280     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   281 
   282     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   283     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   284     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   285     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   286     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   287     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   288 
   289 * If methods "eval" and "evaluation" encounter a structured proof state
   290 with !!/==>, only the conclusion is evaluated to True (if possible),
   291 avoiding strange error messages.
   292 
   293 * Simplifier: simproc for let expressions now unfolds if bound variable
   294 occurs at most one time in let expression body.  INCOMPATIBILITY.
   295 
   296 * New classes "top" and "bot" with corresponding operations "top" and "bot"
   297 in theory Orderings;  instantiation of class "complete_lattice" requires
   298 instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   299 
   300 * Changed definition lemma "less_fun_def" in order to provide an instance
   301 for preorders on functions;  use lemma "less_le" instead.  INCOMPATIBILITY.
   302 
   303 * Unified theorem tables for both code code generators.  Thus
   304 [code func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   305 
   306 * Constants "undefined" and "default" replace "arbitrary".  Usually
   307 "undefined" is the right choice to replace "arbitrary", though logically
   308 there is no difference.  INCOMPATIBILITY.
   309 
   310 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   311 Posix processes.  Avoids potentially expensive forking of the ML
   312 process.  New thread-based implementation also works on non-Unix
   313 platforms (Cygwin).  Provers are no longer hardwired, but defined
   314 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   315 commands are covered in the isar-ref manual
   316 
   317 * Wrapper scripts for remote SystemOnTPTP service allows to use
   318 sledgehammer without local ATP installation (Vampire etc.).  See also
   319 ISABELLE_HOME/contrib/SystemOnTPTP and the VAMPIRE_HOME setting
   320 variable.  Other provers may be included via suitable ML wrappers, see
   321 also src/HOL/ATP_Linkup.thy.
   322 
   323 * Normalization by evaluation now allows non-leftlinear equations.
   324 Declare with attribute [code nbe].
   325 
   326 * Command "value" now integrates different evaluation
   327 mechanisms.  The result of the first successful evaluation mechanism
   328 is printed.  In square brackets a particular named evaluation
   329 mechanisms may be specified (currently, [SML], [code] or [nbe]).  See
   330 further src/HOL/ex/Eval_Examples.thy.
   331 
   332 * New method "sizechange" to automate termination proofs using (a
   333 modification of) the size-change principle. Requires SAT solver. See
   334 src/HOL/ex/Termination.thy for examples.
   335 
   336 * HOL/Orderings: class "wellorder" moved here, with explicit induction
   337 rule "less_induct" as assumption.  For instantiation of "wellorder" by
   338 means of predicate "wf", use rule wf_wellorderI.  INCOMPATIBILITY.
   339 
   340 * HOL/Orderings: added class "preorder" as superclass of "order".
   341 INCOMPATIBILITY: Instantiation proofs for order, linorder
   342 etc. slightly changed.  Some theorems named order_class.* now named
   343 preorder_class.*.
   344 
   345 * HOL/Finite_Set: added a new fold combinator of type
   346   ('a => 'b => 'b) => 'b => 'a set => 'b
   347 Occasionally this is more convenient than the old fold combinator which is
   348 now defined in terms of the new one and renamed to fold_image.
   349 
   350 * HOL/Ring_and_Field and HOL/OrderedGroup: The lemmas "group_simps" and
   351 "ring_simps" have been replaced by "algebra_simps" (which can be extended with
   352 further lemmas!). At the moment both still exist but the former will disappear
   353 at some point.
   354 
   355 * HOL/Ring_and_Field and HOL/Divides: Definition of "op dvd" has been
   356 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   357 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   358 of lemmas from Divides has been generalized from nat to class
   359 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   360 renames resulting from duplicate elimination:
   361 
   362     dvd_def_mod ~>          dvd_eq_mod_eq_0
   363     zero_dvd_iff ~>         dvd_0_left_iff
   364     dvd_0 ~>                dvd_0_right
   365     DIVISION_BY_ZERO_DIV ~> div_by_0
   366     DIVISION_BY_ZERO_MOD ~> mod_by_0
   367     mult_div ~>             div_mult_self2_is_id
   368     mult_mod ~>             mod_mult_self2_is_0
   369 
   370 * HOL/Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   371 zlcm (for int); carried together from various gcd/lcm developements in
   372 the HOL Distribution.  zgcd and zlcm replace former igcd and ilcm;
   373 corresponding theorems renamed accordingly.  INCOMPATIBILY.  To
   374 recover tupled syntax, use syntax declarations like:
   375 
   376     hide (open) const gcd
   377     abbreviation gcd where
   378       "gcd == (%(a, b). GCD.gcd a b)"
   379     notation (output)
   380       GCD.gcd ("gcd '(_, _')")
   381 
   382 (analogously for lcm, zgcd, zlcm).
   383 
   384 * HOL/Real/Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   385 
   386 * The real numbers offer decimal input syntax: 12.34 is translated into
   387   1234/10^4. This translation is not reversed upon output.
   388 
   389 * New ML antiquotation @{code}: takes constant as argument, generates
   390 corresponding code in background and inserts name of the corresponding
   391 resulting ML value/function/datatype constructor binding in place.
   392 All occurrences of @{code} with a single ML block are generated
   393 simultaneously.  Provides a generic and safe interface for
   394 instrumentalizing code generation.  See HOL/ex/Code_Antiq for a toy
   395 example, or HOL/Complex/ex/ReflectedFerrack for a more ambitious
   396 application.  In future you ought refrain from ad-hoc compiling
   397 generated SML code on the ML toplevel.  Note that (for technical
   398 reasons) @{code} cannot refer to constants for which user-defined
   399 serializations are set.  Refer to the corresponding ML counterpart
   400 directly in that cases.
   401 
   402 * Integrated image HOL-Complex with HOL.  Entry points Main.thy and
   403 Complex_Main.thy remain as they are.
   404 
   405 * New image HOL-Plain provides a minimal HOL with the most important
   406 tools available (inductive, datatype, primrec, ...).  By convention
   407 the corresponding theory Plain should be ancestor of every further
   408 (library) theory.  Some library theories now have ancestor Plain
   409 (instead of Main), thus theory Main occasionally has to be imported
   410 explicitly.
   411 
   412 * The metis method now fails in the usual manner, rather than raising
   413 an exception, if it determines that it cannot prove the theorem.
   414 
   415 * The metis method no longer fails because the theorem is too trivial
   416 (contains the empty clause).
   417 
   418 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   419 as the structured Isar versions "cases" and "induct", cf. the
   420 corresponding "cases" and "induct" attributes.  Mutual induction rules
   421 are now presented as a list of individual projections
   422 (e.g. foo_bar.inducts for types foo and bar); the old format with
   423 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   424 rare situations a different rule is selected --- notably nested tuple
   425 elimination instead of former prod.exhaust: use explicit (case_tac t
   426 rule: prod.exhaust) here.
   427 
   428 * Attributes "cases", "induct", "coinduct" support "del" option.
   429 
   430 * Removed fact "case_split_thm", which duplicates "case_split".
   431 
   432 * Command 'rep_datatype': instead of theorem names the command now
   433 takes a list of terms denoting the constructors of the type to be
   434 represented as datatype.  The characteristic theorems have to be
   435 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   436 have disappeared in favour of existing ones:
   437 
   438     unit_induct                 ~> unit.induct
   439     prod_induct                 ~> prod.induct
   440     sum_induct                  ~> sum.induct
   441     Suc_Suc_eq                  ~> nat.inject
   442     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   443 
   444 * Library/Nat_Infinity: added addition, numeral syntax and more
   445 instantiations for algebraic structures.  Removed some duplicate
   446 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   447 
   448 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   449 menu.
   450 
   451 
   452 *** HOL-Algebra ***
   453 
   454 * New locales for orders and lattices where the equivalence relation
   455   is not restricted to equality.  INCOMPATIBILITY: all order and
   456   lattice locales use a record structure with field eq for the
   457   equivalence.
   458 
   459 * New theory of factorial domains.
   460 
   461 * Units_l_inv and Units_r_inv are now simprules by default.
   462 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   463 and/or r_inv will now also require deletion of these lemmas.
   464 
   465 * Renamed the following theorems.  INCOMPATIBILITY.
   466 UpperD ~> Upper_memD
   467 LowerD ~> Lower_memD
   468 least_carrier ~> least_closed
   469 greatest_carrier ~> greatest_closed
   470 greatest_Lower_above ~> greatest_Lower_below
   471 one_zero ~> carrier_one_zero
   472 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   473 
   474 
   475 *** HOL-NSA ***
   476 
   477 * Created new image HOL-NSA, containing theories of nonstandard
   478 analysis which were previously part of HOL-Complex.  Entry point
   479 Hyperreal.thy remains valid, but theories formerly using
   480 Complex_Main.thy should now use new entry point Hypercomplex.thy.
   481 
   482 
   483 *** ZF ***
   484 
   485 * Proof of Zorn's Lemma for partial orders.
   486 
   487 
   488 *** ML ***
   489 
   490 * High-level support for concurrent ML programming, see
   491 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   492 particularly convenient to organize independent functional
   493 computations.  The concept of "synchronized variables" provides a
   494 higher-order interface for components with shared state, avoiding the
   495 delicate details of mutexes and condition variables.  [Poly/ML 5.2.1
   496 or later]
   497 
   498 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   499 to 'a -> thm, while results are always tagged with an authentic oracle
   500 name.  The Isar command 'oracle' is now polymorphic, no argument type
   501 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   502 accordingly.  Note that extra performance may be gained by producing
   503 the cterm carefully, avoiding slow Thm.cterm_of.
   504 
   505 * ML bindings produced via Isar commands are stored within the Isar
   506 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   507 become thread-safe and work with undo as expected (concerning
   508 top-level bindings, not side-effects on global references).
   509 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   510 compiler at runtime; really global bindings need to be given outside a
   511 theory. [Poly/ML 5.2 or later]
   512 
   513 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   514 context. Top-level ML bindings are stored within the proof context in
   515 a purely sequential fashion, disregarding the nested proof structure.
   516 ML bindings introduced by 'ML_prf' are discarded at the end of the
   517 proof.  [Poly/ML 5.2 or later]
   518 
   519 * Generic Toplevel.add_hook interface allows to analyze the result of
   520 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   521 for theorem dependency output of transactions resulting in a new
   522 theory state.
   523 
   524 * Name bindings in higher specification mechanisms (notably
   525 LocalTheory.define, LocalTheory.note, and derived packages) are now
   526 formalized as type Name.binding, replacing old bstring.
   527 INCOMPATIBILITY, need to wrap strings via Name.binding function, see
   528 also Name.name_of.  Packages should pass name bindings given by the
   529 user to underlying specification mechanisms; this enables precise
   530 tracking of source positions, for example.
   531 
   532 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   533 LocalTheory.note etc.) now refer to the *full* internal name, not the
   534 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   535 
   536 * Rules and tactics that read instantiations (read_instantiate,
   537 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   538 context, which is required for parsing and type-checking.  Moreover,
   539 the variables are specified as plain indexnames, not string encodings
   540 thereof.  INCOMPATIBILITY.
   541 
   542 * Disposed old type and term read functions (Sign.read_def_typ,
   543 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   544 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   545 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   546 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   547 resort for legacy applications.
   548 
   549 * Antiquotations: block-structured compilation context indicated by
   550 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   551 
   552   @{let ?pat = term}                      - term abbreviation (HO matching)
   553   @{note name = fact}                     - fact abbreviation
   554   @{thm fact}                             - singleton fact (with attributes)
   555   @{thms fact}                            - general fact (with attributes)
   556   @{lemma prop by method}                 - singleton goal
   557   @{lemma prop by meth1 meth2}            - singleton goal
   558   @{lemma prop1 ... propN by method}      - general goal
   559   @{lemma prop1 ... propN by meth1 meth2} - general goal
   560   @{lemma (open) ...}                     - open derivation
   561 
   562 
   563 *** System ***
   564 
   565 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   566 Poly/ML 5.2.1 or later.
   567 
   568 * The Isabelle "emacs" tool provides a specific interface to invoke
   569 Proof General / Emacs, with more explicit failure if that is not
   570 installed (the old isabelle-interface script silently falls back on
   571 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   572 installation location of the Proof General distribution.
   573 
   574 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   575 the Isabelle process into a JVM/Scala application.  See
   576 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   577 process wrapper has been discontinued.)
   578 
   579 * Status messages (with exact source position information) are
   580 emitted, if proper markup print mode is enabled.  This allows
   581 user-interface components to provide detailed feedback on internal
   582 prover operations.
   583 
   584 * Homegrown Isabelle font with unicode layout, see Isabelle/lib/fonts.
   585 
   586 
   587 
   588 New in Isabelle2008 (June 2008)
   589 -------------------------------
   590 
   591 *** General ***
   592 
   593 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   594 and updated, with formally checked references as hyperlinks.
   595 
   596 * Theory loader: use_thy (and similar operations) no longer set the
   597 implicit ML context, which was occasionally hard to predict and in
   598 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   599 provides a proper context already.
   600 
   601 * Theory loader: old-style ML proof scripts being *attached* to a thy
   602 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   603 'use' within a theory file will do the job.
   604 
   605 * Name space merge now observes canonical order, i.e. the second space
   606 is inserted into the first one, while existing entries in the first
   607 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   608 swap theory imports.
   609 
   610 * Syntax: symbol \<chi> is now considered a letter.  Potential
   611 INCOMPATIBILITY in identifier syntax etc.
   612 
   613 * Outer syntax: string tokens no longer admit escaped white space,
   614 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   615 white space without escapes.
   616 
   617 * Outer syntax: string tokens may contain arbitrary character codes
   618 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   619 "foo_bar".
   620 
   621 
   622 *** Pure ***
   623 
   624 * Context-dependent token translations.  Default setup reverts locally
   625 fixed variables, and adds hilite markup for undeclared frees.
   626 
   627 * Unused theorems can be found using the new command 'unused_thms'.
   628 There are three ways of invoking it:
   629 
   630 (1) unused_thms
   631      Only finds unused theorems in the current theory.
   632 
   633 (2) unused_thms thy_1 ... thy_n -
   634      Finds unused theorems in the current theory and all of its ancestors,
   635      excluding the theories thy_1 ... thy_n and all of their ancestors.
   636 
   637 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   638      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   639      their ancestors, excluding the theories thy_1 ... thy_n and all of
   640      their ancestors.
   641 
   642 In order to increase the readability of the list produced by
   643 unused_thms, theorems that have been created by a particular instance
   644 of a theory command such as 'inductive' or 'function' are considered
   645 to belong to the same "group", meaning that if at least one theorem in
   646 this group is used, the other theorems in the same group are no longer
   647 reported as unused.  Moreover, if all theorems in the group are
   648 unused, only one theorem in the group is displayed.
   649 
   650 Note that proof objects have to be switched on in order for
   651 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   652 usually the case when using Proof General with the default settings).
   653 
   654 * Authentic naming of facts disallows ad-hoc overwriting of previous
   655 theorems within the same name space.  INCOMPATIBILITY, need to remove
   656 duplicate fact bindings, or even accidental fact duplications.  Note
   657 that tools may maintain dynamically scoped facts systematically, using
   658 PureThy.add_thms_dynamic.
   659 
   660 * Command 'hide' now allows to hide from "fact" name space as well.
   661 
   662 * Eliminated destructive theorem database, simpset, claset, and
   663 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   664 update of theories within ML code.
   665 
   666 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   667 INCOMPATIBILITY, object-logics depending on former Pure require
   668 additional setup PureThy.old_appl_syntax_setup; object-logics
   669 depending on former CPure need to refer to Pure.
   670 
   671 * Commands 'use' and 'ML' are now purely functional, operating on
   672 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   673 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   674 INCOMPATIBILITY.
   675 
   676 * Command 'setup': discontinued implicit version with ML reference.
   677 
   678 * Instantiation target allows for simultaneous specification of class
   679 instance operations together with an instantiation proof.
   680 Type-checking phase allows to refer to class operations uniformly.
   681 See src/HOL/Complex/Complex.thy for an Isar example and
   682 src/HOL/Library/Eval.thy for an ML example.
   683 
   684 * Indexing of literal facts: be more serious about including only
   685 facts from the visible specification/proof context, but not the
   686 background context (locale etc.).  Affects `prop` notation and method
   687 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   688 situations.
   689 
   690 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   691 "(open)" option, which used to expose internal bound variables to the
   692 proof text.
   693 
   694 * Isar statements: removed obsolete case "rule_context".
   695 INCOMPATIBILITY, better use explicit fixes/assumes.
   696 
   697 * Locale proofs: default proof step now includes 'unfold_locales';
   698 hence 'proof' without argument may be used to unfold locale
   699 predicates.
   700 
   701 
   702 *** Document preparation ***
   703 
   704 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   705 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   706 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   707 spot); renamed link color from "darkblue" to "linkcolor" (default
   708 value unchanged, can be redefined via \definecolor); no longer sets
   709 "a4paper" option (unnecessary or even intrusive).
   710 
   711 * Antiquotation @{lemma A method} proves proposition A by the given
   712 method (either a method name or a method name plus (optional) method
   713 arguments in parentheses) and prints A just like @{prop A}.
   714 
   715 
   716 *** HOL ***
   717 
   718 * New primrec package.  Specification syntax conforms in style to
   719 definition/function/....  No separate induction rule is provided.  The
   720 "primrec" command distinguishes old-style and new-style specifications
   721 by syntax.  The former primrec package is now named OldPrimrecPackage.
   722 When adjusting theories, beware: constants stemming from new-style
   723 primrec specifications have authentic syntax.
   724 
   725 * Metis prover is now an order of magnitude faster, and also works
   726 with multithreading.
   727 
   728 * Metis: the maximum number of clauses that can be produced from a
   729 theorem is now given by the attribute max_clauses.  Theorems that
   730 exceed this number are ignored, with a warning printed.
   731 
   732 * Sledgehammer no longer produces structured proofs by default. To
   733 enable, declare [[sledgehammer_full = true]].  Attributes
   734 reconstruction_modulus, reconstruction_sorts renamed
   735 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   736 
   737 * Method "induct_scheme" derives user-specified induction rules
   738 from well-founded induction and completeness of patterns. This factors
   739 out some operations that are done internally by the function package
   740 and makes them available separately.  See
   741 src/HOL/ex/Induction_Scheme.thy for examples.
   742 
   743 * More flexible generation of measure functions for termination
   744 proofs: Measure functions can be declared by proving a rule of the
   745 form "is_measure f" and giving it the [measure_function] attribute.
   746 The "is_measure" predicate is logically meaningless (always true), and
   747 just guides the heuristic.  To find suitable measure functions, the
   748 termination prover sets up the goal "is_measure ?f" of the appropriate
   749 type and generates all solutions by prolog-style backwards proof using
   750 the declared rules.
   751 
   752 This setup also deals with rules like 
   753 
   754   "is_measure f ==> is_measure (list_size f)"
   755 
   756 which accommodates nested datatypes that recurse through lists.
   757 Similar rules are predeclared for products and option types.
   758 
   759 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   760 
   761   INCOMPATIBILITIES:
   762 
   763   - Definitions of overloaded constants on sets have to be replaced by
   764     definitions on => and bool.
   765 
   766   - Some definitions of overloaded operators on sets can now be proved
   767     using the definitions of the operators on => and bool.  Therefore,
   768     the following theorems have been renamed:
   769 
   770       subset_def   -> subset_eq
   771       psubset_def  -> psubset_eq
   772       set_diff_def -> set_diff_eq
   773       Compl_def    -> Compl_eq
   774       Sup_set_def  -> Sup_set_eq
   775       Inf_set_def  -> Inf_set_eq
   776       sup_set_def  -> sup_set_eq
   777       inf_set_def  -> inf_set_eq
   778 
   779   - Due to the incompleteness of the HO unification algorithm, some
   780     rules such as subst may require manual instantiation, if some of
   781     the unknowns in the rule is a set.
   782 
   783   - Higher order unification and forward proofs:
   784     The proof pattern
   785 
   786       have "P (S::'a set)" <...>
   787       then have "EX S. P S" ..
   788 
   789     no longer works (due to the incompleteness of the HO unification
   790     algorithm) and must be replaced by the pattern
   791 
   792       have "EX S. P S"
   793       proof
   794         show "P S" <...>
   795       qed
   796 
   797   - Calculational reasoning with subst (or similar rules):
   798     The proof pattern
   799 
   800       have "P (S::'a set)" <...>
   801       also have "S = T" <...>
   802       finally have "P T" .
   803 
   804     no longer works (for similar reasons as the previous example) and
   805     must be replaced by something like
   806 
   807       have "P (S::'a set)" <...>
   808       moreover have "S = T" <...>
   809       ultimately have "P T" by simp
   810 
   811   - Tactics or packages written in ML code:
   812     Code performing pattern matching on types via
   813 
   814       Type ("set", [T]) => ...
   815 
   816     must be rewritten. Moreover, functions like strip_type or
   817     binder_types no longer return the right value when applied to a
   818     type of the form
   819 
   820       T1 => ... => Tn => U => bool
   821 
   822     rather than
   823 
   824       T1 => ... => Tn => U set
   825 
   826 * Merged theories Wellfounded_Recursion, Accessible_Part and
   827 Wellfounded_Relations to theory Wellfounded.
   828 
   829 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
   830 
   831 * Class finite no longer treats UNIV as class parameter.  Use class
   832 enum from theory Library/Enum instead to achieve a similar effect.
   833 INCOMPATIBILITY.
   834 
   835 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
   836 and "Cons".  INCOMPATIBILITY.
   837 
   838 * HOL (and FOL): renamed variables in rules imp_elim and swap.
   839 Potential INCOMPATIBILITY.
   840 
   841 * Theory Product_Type: duplicated lemmas split_Pair_apply and
   842 injective_fst_snd removed, use split_eta and prod_eqI instead.
   843 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
   844 
   845 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
   846 the same name in theory Orderings:
   847 
   848   less_trans
   849   less_linear
   850   le_imp_less_or_eq
   851   le_less_trans
   852   less_le_trans
   853   less_not_sym
   854   less_asym
   855 
   856 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
   857 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
   858 and different variable names.
   859 
   860 * Library/Option_ord.thy: Canonical order on option type.
   861 
   862 * Library/RBT.thy: Red-black trees, an efficient implementation of
   863 finite maps.
   864 
   865 * Library/Countable.thy: Type class for countable types.
   866 
   867 * Theory Int: The representation of numerals has changed.  The infix
   868 operator BIT and the bit datatype with constructors B0 and B1 have
   869 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
   870 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
   871 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
   872 accordingly.
   873 
   874 * Theory Nat: definition of <= and < on natural numbers no longer
   875 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
   876 le_def and less_def have disappeared.  Consider lemmas not_less
   877 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
   878 
   879 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
   880 (whose purpose mainly is for various fold_set functionals) have been
   881 abandoned in favor of the existing algebraic classes
   882 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
   883 lower_semilattice (resp. upper_semilattice) and linorder.
   884 INCOMPATIBILITY.
   885 
   886 * Theory Transitive_Closure: induct and cases rules now declare proper
   887 case_names ("base" and "step").  INCOMPATIBILITY.
   888 
   889 * Theorem Inductive.lfp_ordinal_induct generalized to complete
   890 lattices.  The form set-specific version is available as
   891 Inductive.lfp_ordinal_induct_set.
   892 
   893 * Renamed theorems "power.simps" to "power_int.simps".
   894 INCOMPATIBILITY.
   895 
   896 * Class semiring_div provides basic abstract properties of semirings
   897 with division and modulo operations.  Subsumes former class dvd_mod.
   898 
   899 * Merged theories IntDef, Numeral and IntArith into unified theory
   900 Int.  INCOMPATIBILITY.
   901 
   902 * Theory Library/Code_Index: type "index" now represents natural
   903 numbers rather than integers.  INCOMPATIBILITY.
   904 
   905 * New class "uminus" with operation "uminus" (split of from class
   906 "minus" which now only has operation "minus", binary).
   907 INCOMPATIBILITY.
   908 
   909 * Constants "card", "internal_split", "option_map" now with authentic
   910 syntax.  INCOMPATIBILITY.
   911 
   912 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
   913 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
   914 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
   915 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
   916 Sup_set_def, le_def, less_def, option_map_def now with object
   917 equality.  INCOMPATIBILITY.
   918 
   919 * Records. Removed K_record, and replaced it by pure lambda term
   920 %x. c. The simplifier setup is now more robust against eta expansion.
   921 INCOMPATIBILITY: in cases explicitly referring to K_record.
   922 
   923 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
   924 
   925 * Library/ListVector: new theory of arithmetic vector operations.
   926 
   927 * Library/Order_Relation: new theory of various orderings as sets of
   928 pairs.  Defines preorders, partial orders, linear orders and
   929 well-orders on sets and on types.
   930 
   931 
   932 *** ZF ***
   933 
   934 * Renamed some theories to allow to loading both ZF and HOL in the
   935 same session:
   936 
   937   Datatype  -> Datatype_ZF
   938   Inductive -> Inductive_ZF
   939   Int       -> Int_ZF
   940   IntDiv    -> IntDiv_ZF
   941   Nat       -> Nat_ZF
   942   List      -> List_ZF
   943   Main      -> Main_ZF
   944 
   945 INCOMPATIBILITY: ZF theories that import individual theories below
   946 Main might need to be adapted.  Regular theory Main is still
   947 available, as trivial extension of Main_ZF.
   948 
   949 
   950 *** ML ***
   951 
   952 * ML within Isar: antiquotation @{const name} or @{const
   953 name(typargs)} produces statically-checked Const term.
   954 
   955 * Functor NamedThmsFun: data is available to the user as dynamic fact
   956 (of the same name).  Removed obsolete print command.
   957 
   958 * Removed obsolete "use_legacy_bindings" function.
   959 
   960 * The ``print mode'' is now a thread-local value derived from a global
   961 template (the former print_mode reference), thus access becomes
   962 non-critical.  The global print_mode reference is for session
   963 management only; user-code should use print_mode_value,
   964 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
   965 
   966 * Functions system/system_out provide a robust way to invoke external
   967 shell commands, with propagation of interrupts (requires Poly/ML
   968 5.2.1).  Do not use OS.Process.system etc. from the basis library!
   969 
   970 
   971 *** System ***
   972 
   973 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
   974 in accordance with Proof General 3.7, which prefers GNU emacs.
   975 
   976 * isatool tty runs Isabelle process with plain tty interaction;
   977 optional line editor may be specified via ISABELLE_LINE_EDITOR
   978 setting, the default settings attempt to locate "ledit" and "rlwrap".
   979 
   980 * isatool browser now works with Cygwin as well, using general
   981 "javapath" function defined in Isabelle process environment.
   982 
   983 * YXML notation provides a simple and efficient alternative to
   984 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
   985 isatool yxml as described in the Isabelle system manual.
   986 
   987 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
   988 provides general wrapper for managing an Isabelle process in a robust
   989 fashion, with ``cooked'' output from stdin/stderr.
   990 
   991 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
   992 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
   993 
   994 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
   995 way of changing the user's settings is via
   996 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
   997 script.
   998 
   999 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1000 cores of the underlying machine, which is a good starting point for
  1001 optimal performance tuning.  The corresponding usedir option -M allows
  1002 "max" as an alias for "0".  WARNING: does not work on certain versions
  1003 of Mac OS (with Poly/ML 5.1).
  1004 
  1005 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1006 adverse effect of Isabelle flooding interactive front-ends (notably
  1007 ProofGeneral / XEmacs).
  1008 
  1009 
  1010 
  1011 New in Isabelle2007 (November 2007)
  1012 -----------------------------------
  1013 
  1014 *** General ***
  1015 
  1016 * More uniform information about legacy features, notably a
  1017 warning/error of "Legacy feature: ...", depending on the state of the
  1018 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1019 legacy features will disappear eventually.
  1020 
  1021 * Theory syntax: the header format ``theory A = B + C:'' has been
  1022 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1023 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1024 
  1025 * Theory syntax: the old non-Isar theory file format has been
  1026 discontinued altogether.  Note that ML proof scripts may still be used
  1027 with Isar theories; migration is usually quite simple with the ML
  1028 function use_legacy_bindings.  INCOMPATIBILITY.
  1029 
  1030 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1031 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1032 quotes.
  1033 
  1034 * Theory loader: be more serious about observing the static theory
  1035 header specifications (including optional directories), but not the
  1036 accidental file locations of previously successful loads.  The strict
  1037 update policy of former update_thy is now already performed by
  1038 use_thy, so the former has been removed; use_thys updates several
  1039 theories simultaneously, just as 'imports' within a theory header
  1040 specification, but without merging the results.  Potential
  1041 INCOMPATIBILITY: may need to refine theory headers and commands
  1042 ROOT.ML which depend on load order.
  1043 
  1044 * Theory loader: optional support for content-based file
  1045 identification, instead of the traditional scheme of full physical
  1046 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1047 (cf. the system manual).  The new scheme allows to work with
  1048 non-finished theories in persistent session images, such that source
  1049 files may be moved later on without requiring reloads.
  1050 
  1051 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1052 file (with the same base name as the theory) are considered a legacy
  1053 feature, which will disappear eventually. Even now, the theory loader
  1054 no longer maintains dependencies on such files.
  1055 
  1056 * Syntax: the scope for resolving ambiguities via type-inference is
  1057 now limited to individual terms, instead of whole simultaneous
  1058 specifications as before. This greatly reduces the complexity of the
  1059 syntax module and improves flexibility by separating parsing and
  1060 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1061 'fixes' etc.) are required in rare situations.
  1062 
  1063 * Syntax: constants introduced by new-style packages ('definition',
  1064 'abbreviation' etc.) are passed through the syntax module in
  1065 ``authentic mode''. This means that associated mixfix annotations
  1066 really stick to such constants, independently of potential name space
  1067 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1068 trees are represented slightly differently, may need to adapt syntax
  1069 translations accordingly. Use CONST marker in 'translations' and
  1070 @{const_syntax} antiquotation in 'parse_translation' etc.
  1071 
  1072 * Legacy goal package: reduced interface to the bare minimum required
  1073 to keep existing proof scripts running.  Most other user-level
  1074 functions are now part of the OldGoals structure, which is *not* open
  1075 by default (consider isatool expandshort before open OldGoals).
  1076 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1077 these tend to cause confusion about the actual goal (!) context being
  1078 used here, which is not necessarily the same as the_context().
  1079 
  1080 * Command 'find_theorems': supports "*" wild-card in "name:"
  1081 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1082 support a specific search form (see ProofGeneral/CHANGES).
  1083 
  1084 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1085 by default, which means that "prems" (and also "fixed variables") are
  1086 suppressed from proof state output.  Note that the ProofGeneral
  1087 settings mechanism allows to change and save options persistently, but
  1088 older versions of Isabelle will fail to start up if a negative prems
  1089 limit is imposed.
  1090 
  1091 * Local theory targets may be specified by non-nested blocks of
  1092 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1093 contain definitions, theorems etc., including any derived mechanism
  1094 that has been implemented on top of these primitives.  This concept
  1095 generalizes the existing ``theorem (in ...)'' towards more versatility
  1096 and scalability.
  1097 
  1098 * Proof General interface: proper undo of final 'end' command;
  1099 discontinued Isabelle/classic mode (ML proof scripts).
  1100 
  1101 
  1102 *** Document preparation ***
  1103 
  1104 * Added antiquotation @{theory name} which prints the given name,
  1105 after checking that it refers to a valid ancestor theory in the
  1106 current context.
  1107 
  1108 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1109 check the given source text as ML type/structure, printing verbatim.
  1110 
  1111 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1112 "c args == rhs" given in the current context.  (Any number of
  1113 arguments may be given on the LHS.)
  1114 
  1115 
  1116 *** Pure ***
  1117 
  1118 * The 'class' package offers a combination of axclass and locale to
  1119 achieve Haskell-like type classes in Isabelle.  Definitions and
  1120 theorems within a class context produce both relative results (with
  1121 implicit parameters according to the locale context), and polymorphic
  1122 constants with qualified polymorphism (according to the class
  1123 context).  Within the body context of a 'class' target, a separate
  1124 syntax layer ("user space type system") takes care of converting
  1125 between global polymorphic consts and internal locale representation.
  1126 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1127 "isatool doc classes" provides a tutorial.
  1128 
  1129 * Generic code generator framework allows to generate executable
  1130 code for ML and Haskell (including Isabelle classes).  A short usage
  1131 sketch:
  1132 
  1133     internal compilation:
  1134         export_code <list of constants (term syntax)> in SML
  1135     writing SML code to a file:
  1136         export_code <list of constants (term syntax)> in SML <filename>
  1137     writing OCaml code to a file:
  1138         export_code <list of constants (term syntax)> in OCaml <filename>
  1139     writing Haskell code to a bunch of files:
  1140         export_code <list of constants (term syntax)> in Haskell <filename>
  1141 
  1142     evaluating closed propositions to True/False using code generation:
  1143         method ``eval''
  1144 
  1145 Reasonable default setup of framework in HOL.
  1146 
  1147 Theorem attributs for selecting and transforming function equations theorems:
  1148 
  1149     [code fun]:        select a theorem as function equation for a specific constant
  1150     [code fun del]:    deselect a theorem as function equation for a specific constant
  1151     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1152     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1153 
  1154 User-defined serializations (target in {SML, OCaml, Haskell}):
  1155 
  1156     code_const <and-list of constants (term syntax)>
  1157       {(target) <and-list of const target syntax>}+
  1158 
  1159     code_type <and-list of type constructors>
  1160       {(target) <and-list of type target syntax>}+
  1161 
  1162     code_instance <and-list of instances>
  1163       {(target)}+
  1164         where instance ::= <type constructor> :: <class>
  1165 
  1166     code_class <and_list of classes>
  1167       {(target) <and-list of class target syntax>}+
  1168         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1169 
  1170 code_instance and code_class only are effective to target Haskell.
  1171 
  1172 For example usage see src/HOL/ex/Codegenerator.thy and
  1173 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1174 generation from Isabelle/HOL theories is available via "isatool doc
  1175 codegen".
  1176 
  1177 * Code generator: consts in 'consts_code' Isar commands are now
  1178 referred to by usual term syntax (including optional type
  1179 annotations).
  1180 
  1181 * Command 'no_translations' removes translation rules from theory
  1182 syntax.
  1183 
  1184 * Overloaded definitions are now actually checked for acyclic
  1185 dependencies.  The overloading scheme is slightly more general than
  1186 that of Haskell98, although Isabelle does not demand an exact
  1187 correspondence to type class and instance declarations.
  1188 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1189 exotic versions of overloading -- at the discretion of the user!
  1190 
  1191 Polymorphic constants are represented via type arguments, i.e. the
  1192 instantiation that matches an instance against the most general
  1193 declaration given in the signature.  For example, with the declaration
  1194 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1195 as c(nat).  Overloading is essentially simultaneous structural
  1196 recursion over such type arguments.  Incomplete specification patterns
  1197 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1198 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1199 Command 'print_theory' outputs the normalized system of recursive
  1200 equations, see section "definitions".
  1201 
  1202 * Configuration options are maintained within the theory or proof
  1203 context (with name and type bool/int/string), providing a very simple
  1204 interface to a poor-man's version of general context data.  Tools may
  1205 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1206 these values using Config.get etc.  Users may change options via an
  1207 associated attribute of the same name.  This form of context
  1208 declaration works particularly well with commands 'declare' or
  1209 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1210 very easy to avoid global references, which would not observe Isar
  1211 toplevel undo/redo and fail to work with multithreading.
  1212 
  1213 Various global ML references of Pure and HOL have been turned into
  1214 configuration options:
  1215 
  1216   Unify.search_bound		unify_search_bound
  1217   Unify.trace_bound		unify_trace_bound
  1218   Unify.trace_simp		unify_trace_simp
  1219   Unify.trace_types		unify_trace_types
  1220   Simplifier.simp_depth_limit	simp_depth_limit
  1221   Blast.depth_limit		blast_depth_limit
  1222   DatatypeProp.dtK		datatype_distinctness_limit
  1223   fast_arith_neq_limit  	fast_arith_neq_limit
  1224   fast_arith_split_limit	fast_arith_split_limit
  1225 
  1226 * Named collections of theorems may be easily installed as context
  1227 data using the functor NamedThmsFun (see also
  1228 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1229 attributes; there is also a toplevel print command.  This facility is
  1230 just a common case of general context data, which is the preferred way
  1231 for anything more complex than just a list of facts in canonical
  1232 order.
  1233 
  1234 * Isar: command 'declaration' augments a local theory by generic
  1235 declaration functions written in ML.  This enables arbitrary content
  1236 being added to the context, depending on a morphism that tells the
  1237 difference of the original declaration context wrt. the application
  1238 context encountered later on.
  1239 
  1240 * Isar: proper interfaces for simplification procedures.  Command
  1241 'simproc_setup' declares named simprocs (with match patterns, and body
  1242 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1243 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1244 
  1245 * Isar: an extra pair of brackets around attribute declarations
  1246 abbreviates a theorem reference involving an internal dummy fact,
  1247 which will be ignored later --- only the effect of the attribute on
  1248 the background context will persist.  This form of in-place
  1249 declarations is particularly useful with commands like 'declare' and
  1250 'using', for example ``have A using [[simproc a]] by simp''.
  1251 
  1252 * Isar: method "assumption" (and implicit closing of subproofs) now
  1253 takes simple non-atomic goal assumptions into account: after applying
  1254 an assumption as a rule the resulting subgoals are solved by atomic
  1255 assumption steps.  This is particularly useful to finish 'obtain'
  1256 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1257 without referring to the original premise "!!x. P x ==> thesis" in the
  1258 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1259 more permissive.
  1260 
  1261 * Isar: implicit use of prems from the Isar proof context is
  1262 considered a legacy feature.  Common applications like ``have A .''
  1263 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1264 referencing facts explicitly here improves readability and
  1265 maintainability of proof texts.
  1266 
  1267 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1268 the obtained context from the course of reasoning!  For example:
  1269 
  1270   assume "EX x y. A x & B y"   -- "any previous fact"
  1271   then guess x and y by clarify
  1272 
  1273 This technique is potentially adventurous, depending on the facts and
  1274 proof tools being involved here.
  1275 
  1276 * Isar: known facts from the proof context may be specified as literal
  1277 propositions, using ASCII back-quote syntax.  This works wherever
  1278 named facts used to be allowed so far, in proof commands, proof
  1279 methods, attributes etc.  Literal facts are retrieved from the context
  1280 according to unification of type and term parameters.  For example,
  1281 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1282 theorems in the current context, then these are valid literal facts:
  1283 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1284 
  1285 There is also a proof method "fact" which does the same composition
  1286 for explicit goal states, e.g. the following proof texts coincide with
  1287 certain special cases of literal facts:
  1288 
  1289   have "A" by fact                 ==  note `A`
  1290   have "A ==> B" by fact           ==  note `A ==> B`
  1291   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1292   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1293 
  1294 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1295 outer syntax.  Thus symbolic identifiers may be used without
  1296 additional white space in declarations like this: ``assume *: A''.
  1297 
  1298 * Isar: 'print_facts' prints all local facts of the current context,
  1299 both named and unnamed ones.
  1300 
  1301 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1302 
  1303   def x == "t" and y == "u"
  1304 
  1305 * Isar: added command 'unfolding', which is structurally similar to
  1306 'using', but affects both the goal state and facts by unfolding given
  1307 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1308 'unfolded' attribute may be replaced by first-class proof text.
  1309 
  1310 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1311 and command 'unfolding' now all support object-level equalities
  1312 (potentially conditional).  The underlying notion of rewrite rule is
  1313 analogous to the 'rule_format' attribute, but *not* that of the
  1314 Simplifier (which is usually more generous).
  1315 
  1316 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1317 premises of a theorem by n. Useful in conjunction with drule.
  1318 
  1319 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1320 method expression within a sandbox consisting of the first N
  1321 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1322 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1323 simplifies all new goals that emerge from applying rule foo to the
  1324 originally first one.
  1325 
  1326 * Isar: schematic goals are no longer restricted to higher-order
  1327 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1328 expected.
  1329 
  1330 * Isar: the conclusion of a long theorem statement is now either
  1331 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1332 (essentially a disjunction of cases with local parameters and
  1333 assumptions).  The latter allows to express general elimination rules
  1334 adequately; in this notation common elimination rules look like this:
  1335 
  1336   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1337     assumes "EX x. P x"
  1338     obtains x where "P x"
  1339 
  1340   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1341     assumes "A & B"
  1342     obtains A and B
  1343 
  1344   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1345     assumes "A | B"
  1346     obtains
  1347       A
  1348     | B
  1349 
  1350 The subsequent classical rules even refer to the formal "thesis"
  1351 explicitly:
  1352 
  1353   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1354     obtains "~ thesis"
  1355 
  1356   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1357     obtains "thesis ==> something"
  1358 
  1359 The actual proof of an 'obtains' statement is analogous to that of the
  1360 Isar proof element 'obtain', only that there may be several cases.
  1361 Optional case names may be specified in parentheses; these will be
  1362 available both in the present proof and as annotations in the
  1363 resulting rule, for later use with the 'cases' method (cf. attribute
  1364 case_names).
  1365 
  1366 * Isar: the assumptions of a long theorem statement are available as
  1367 "assms" fact in the proof context.  This is more appropriate than the
  1368 (historical) "prems", which refers to all assumptions of the current
  1369 context, including those from the target locale, proof body etc.
  1370 
  1371 * Isar: 'print_statement' prints theorems from the current theory or
  1372 proof context in long statement form, according to the syntax of a
  1373 top-level lemma.
  1374 
  1375 * Isar: 'obtain' takes an optional case name for the local context
  1376 introduction rule (default "that").
  1377 
  1378 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1379 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1380 to occur.
  1381 
  1382 * Pure: syntax "CONST name" produces a fully internalized constant
  1383 according to the current context.  This is particularly useful for
  1384 syntax translations that should refer to internal constant
  1385 representations independently of name spaces.
  1386 
  1387 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1388 instead of "FOO ". This allows multiple binder declarations to coexist
  1389 in the same context.  INCOMPATIBILITY.
  1390 
  1391 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1392 primitive that also works in a locale context (both for constants and
  1393 fixed variables). Type declaration and internal syntactic representation
  1394 of given constants retrieved from the context. Likewise, the
  1395 'no_notation' command allows to remove given syntax annotations from the
  1396 current context.
  1397 
  1398 * Isar/locales: new derived specification elements 'axiomatization',
  1399 'definition', 'abbreviation', which support type-inference, admit
  1400 object-level specifications (equality, equivalence).  See also the
  1401 isar-ref manual.  Examples:
  1402 
  1403   axiomatization
  1404     eq  (infix "===" 50) where
  1405     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1406 
  1407   definition "f x y = x + y + 1"
  1408   definition g where "g x = f x x"
  1409 
  1410   abbreviation
  1411     neq  (infix "=!=" 50) where
  1412     "x =!= y == ~ (x === y)"
  1413 
  1414 These specifications may be also used in a locale context.  Then the
  1415 constants being introduced depend on certain fixed parameters, and the
  1416 constant name is qualified by the locale base name.  An internal
  1417 abbreviation takes care for convenient input and output, making the
  1418 parameters implicit and using the original short name.  See also
  1419 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1420 entities from a monomorphic theory.
  1421 
  1422 Presently, abbreviations are only available 'in' a target locale, but
  1423 not inherited by general import expressions.  Also note that
  1424 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1425 'translations' in common applications.  The "no_abbrevs" print mode
  1426 prevents folding of abbreviations in term output.
  1427 
  1428 Concrete syntax is attached to specified constants in internal form,
  1429 independently of name spaces.  The parse tree representation is
  1430 slightly different -- use 'notation' instead of raw 'syntax', and
  1431 'translations' with explicit "CONST" markup to accommodate this.
  1432 
  1433 * Pure/Isar: unified syntax for new-style specification mechanisms
  1434 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1435 full type inference and dummy patterns ("_").  For example:
  1436 
  1437   definition "K x _ = x"
  1438 
  1439   inductive conj for A B
  1440   where "A ==> B ==> conj A B"
  1441 
  1442 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1443 the current context.  Print mode "no_abbrevs" prevents inversion of
  1444 abbreviations on output.
  1445 
  1446 * Isar/locales: improved parameter handling: use of locales "var" and
  1447 "struct" no longer necessary; - parameter renamings are no longer
  1448 required to be injective.  For example, this allows to define
  1449 endomorphisms as locale endom = homom mult mult h.
  1450 
  1451 * Isar/locales: changed the way locales with predicates are defined.
  1452 Instead of accumulating the specification, the imported expression is
  1453 now an interpretation.  INCOMPATIBILITY: different normal form of
  1454 locale expressions.  In particular, in interpretations of locales with
  1455 predicates, goals repesenting already interpreted fragments are not
  1456 removed automatically.  Use methods `intro_locales' and
  1457 `unfold_locales'; see below.
  1458 
  1459 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1460 provide backward reasoning on locales predicates.  The methods are
  1461 aware of interpretations and discharge corresponding goals.
  1462 `intro_locales' is less aggressive then `unfold_locales' and does not
  1463 unfold predicates to assumptions.
  1464 
  1465 * Isar/locales: the order in which locale fragments are accumulated
  1466 has changed.  This enables to override declarations from fragments due
  1467 to interpretations -- for example, unwanted simp rules.
  1468 
  1469 * Isar/locales: interpretation in theories and proof contexts has been
  1470 extended.  One may now specify (and prove) equations, which are
  1471 unfolded in interpreted theorems.  This is useful for replacing
  1472 defined concepts (constants depending on locale parameters) by
  1473 concepts already existing in the target context.  Example:
  1474 
  1475   interpretation partial_order ["op <= :: [int, int] => bool"]
  1476     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1477 
  1478 Typically, the constant `partial_order.less' is created by a
  1479 definition specification element in the context of locale
  1480 partial_order.
  1481 
  1482 * Method "induct": improved internal context management to support
  1483 local fixes and defines on-the-fly. Thus explicit meta-level
  1484 connectives !!  and ==> are rarely required anymore in inductive goals
  1485 (using object-logic connectives for this purpose has been long
  1486 obsolete anyway). Common proof patterns are explained in
  1487 src/HOL/Induct/Common_Patterns.thy, see also
  1488 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1489 examples.
  1490 
  1491 * Method "induct": improved handling of simultaneous goals. Instead of
  1492 introducing object-level conjunction, the statement is now split into
  1493 several conclusions, while the corresponding symbolic cases are nested
  1494 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1495 see src/HOL/Induct/Common_Patterns.thy, for example.
  1496 
  1497 * Method "induct": mutual induction rules are now specified as a list
  1498 of rule sharing the same induction cases. HOL packages usually provide
  1499 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1500 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1501 mutual induction rules differently, i.e. like this:
  1502 
  1503   (induct rule: foo_bar.inducts)
  1504   (induct set: foo bar)
  1505   (induct pred: foo bar)
  1506   (induct type: foo bar)
  1507 
  1508 The ML function ProjectRule.projections turns old-style rules into the
  1509 new format.
  1510 
  1511 * Method "coinduct": dual of induction, see
  1512 src/HOL/Library/Coinductive_List.thy for various examples.
  1513 
  1514 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1515 considered a legacy feature.
  1516 
  1517 * Attribute "symmetric" produces result with standardized schematic
  1518 variables (index 0).  Potential INCOMPATIBILITY.
  1519 
  1520 * Simplifier: by default the simplifier trace only shows top level
  1521 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1522 default. Thus there is less danger of being flooded by the trace. The
  1523 trace indicates where parts have been suppressed.
  1524   
  1525 * Provers/classical: removed obsolete classical version of elim_format
  1526 attribute; classical elim/dest rules are now treated uniformly when
  1527 manipulating the claset.
  1528 
  1529 * Provers/classical: stricter checks to ensure that supplied intro,
  1530 dest and elim rules are well-formed; dest and elim rules must have at
  1531 least one premise.
  1532 
  1533 * Provers/classical: attributes dest/elim/intro take an optional
  1534 weight argument for the rule (just as the Pure versions).  Weights are
  1535 ignored by automated tools, but determine the search order of single
  1536 rule steps.
  1537 
  1538 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1539 where the body does not mention the bound variable.  Note that dummy
  1540 patterns implicitly depend on their context of bounds, which makes
  1541 "{_. _}" match any set comprehension as expected.  Potential
  1542 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1543 constant "_idtdummy" in the binding position.
  1544 
  1545 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1546 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1547 for example "A -> B" => "Pi A (%_. B)".
  1548 
  1549 * Pure: 'class_deps' command visualizes the subclass relation, using
  1550 the graph browser tool.
  1551 
  1552 * Pure: 'print_theory' now suppresses certain internal declarations by
  1553 default; use '!' option for full details.
  1554 
  1555 
  1556 *** HOL ***
  1557 
  1558 * Method "metis" proves goals by applying the Metis general-purpose
  1559 resolution prover (see also http://gilith.com/software/metis/).
  1560 Examples are in the directory MetisExamples.  WARNING: the
  1561 Isabelle/HOL-Metis integration does not yet work properly with
  1562 multi-threading.
  1563   
  1564 * Command 'sledgehammer' invokes external automatic theorem provers as
  1565 background processes.  It generates calls to the "metis" method if
  1566 successful. These can be pasted into the proof.  Users do not have to
  1567 wait for the automatic provers to return.  WARNING: does not really
  1568 work with multi-threading.
  1569 
  1570 * New "auto_quickcheck" feature tests outermost goal statements for
  1571 potential counter-examples.  Controlled by ML references
  1572 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1573 5000 milliseconds).  Fails silently if statements is outside of
  1574 executable fragment, or any other codgenerator problem occurs.
  1575 
  1576 * New constant "undefined" with axiom "undefined x = undefined".
  1577 
  1578 * Added class "HOL.eq", allowing for code generation with polymorphic
  1579 equality.
  1580 
  1581 * Some renaming of class constants due to canonical name prefixing in
  1582 the new 'class' package:
  1583 
  1584     HOL.abs ~> HOL.abs_class.abs
  1585     HOL.divide ~> HOL.divide_class.divide
  1586     0 ~> HOL.zero_class.zero
  1587     1 ~> HOL.one_class.one
  1588     op + ~> HOL.plus_class.plus
  1589     op - ~> HOL.minus_class.minus
  1590     uminus ~> HOL.minus_class.uminus
  1591     op * ~> HOL.times_class.times
  1592     op < ~> HOL.ord_class.less
  1593     op <= > HOL.ord_class.less_eq
  1594     Nat.power ~> Power.power_class.power
  1595     Nat.size ~> Nat.size_class.size
  1596     Numeral.number_of ~> Numeral.number_class.number_of
  1597     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1598     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1599     Orderings.min ~> Orderings.ord_class.min
  1600     Orderings.max ~> Orderings.ord_class.max
  1601     Divides.op div ~> Divides.div_class.div
  1602     Divides.op mod ~> Divides.div_class.mod
  1603     Divides.op dvd ~> Divides.div_class.dvd
  1604 
  1605 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1606 
  1607 a) User-defined constants using any of the names "plus", "minus",
  1608 "times", "less" or "less_eq". The standard syntax translations for
  1609 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1610 names.
  1611 
  1612 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1613 INCOMPATIBILITY: use more specific names.
  1614 
  1615 c) Permutative equations (e.g. "a + b = b + a")
  1616 Since the change of names also changes the order of terms, permutative
  1617 rewrite rules may get applied in a different order. Experience shows
  1618 that this is rarely the case (only two adaptions in the whole Isabelle
  1619 distribution).  INCOMPATIBILITY: rewrite proofs
  1620 
  1621 d) ML code directly refering to constant names
  1622 This in general only affects hand-written proof tactics, simprocs and
  1623 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1624 Consider using @{const_name} antiquotation.
  1625 
  1626 * New class "default" with associated constant "default".
  1627 
  1628 * Function "sgn" is now overloaded and available on int, real, complex
  1629 (and other numeric types), using class "sgn".  Two possible defs of
  1630 sgn are given as equational assumptions in the classes sgn_if and
  1631 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1632 INCOMPATIBILITY.
  1633 
  1634 * Locale "partial_order" now unified with class "order" (cf. theory
  1635 Orderings), added parameter "less".  INCOMPATIBILITY.
  1636 
  1637 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1638 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1639 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1640 
  1641 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1642 changed order of proof goals in instance proofs.
  1643 
  1644 * The transitivity reasoner for partial and linear orders is set up
  1645 for classes "order" and "linorder".  Instances of the reasoner are available
  1646 in all contexts importing or interpreting the corresponding locales.
  1647 Method "order" invokes the reasoner separately; the reasoner
  1648 is also integrated with the Simplifier as a solver.  Diagnostic
  1649 command 'print_orders' shows the available instances of the reasoner
  1650 in the current context.
  1651 
  1652 * Localized monotonicity predicate in theory "Orderings"; integrated
  1653 lemmas max_of_mono and min_of_mono with this predicate.
  1654 INCOMPATIBILITY.
  1655 
  1656 * Formulation of theorem "dense" changed slightly due to integration
  1657 with new class dense_linear_order.
  1658 
  1659 * Uniform lattice theory development in HOL.
  1660 
  1661     constants "meet" and "join" now named "inf" and "sup"
  1662     constant "Meet" now named "Inf"
  1663 
  1664     classes "meet_semilorder" and "join_semilorder" now named
  1665       "lower_semilattice" and "upper_semilattice"
  1666     class "lorder" now named "lattice"
  1667     class "comp_lat" now named "complete_lattice"
  1668 
  1669     Instantiation of lattice classes allows explicit definitions
  1670     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1671 
  1672   INCOMPATIBILITY.  Theorem renames:
  1673 
  1674     meet_left_le            ~> inf_le1
  1675     meet_right_le           ~> inf_le2
  1676     join_left_le            ~> sup_ge1
  1677     join_right_le           ~> sup_ge2
  1678     meet_join_le            ~> inf_sup_ord
  1679     le_meetI                ~> le_infI
  1680     join_leI                ~> le_supI
  1681     le_meet                 ~> le_inf_iff
  1682     le_join                 ~> ge_sup_conv
  1683     meet_idempotent         ~> inf_idem
  1684     join_idempotent         ~> sup_idem
  1685     meet_comm               ~> inf_commute
  1686     join_comm               ~> sup_commute
  1687     meet_leI1               ~> le_infI1
  1688     meet_leI2               ~> le_infI2
  1689     le_joinI1               ~> le_supI1
  1690     le_joinI2               ~> le_supI2
  1691     meet_assoc              ~> inf_assoc
  1692     join_assoc              ~> sup_assoc
  1693     meet_left_comm          ~> inf_left_commute
  1694     meet_left_idempotent    ~> inf_left_idem
  1695     join_left_comm          ~> sup_left_commute
  1696     join_left_idempotent    ~> sup_left_idem
  1697     meet_aci                ~> inf_aci
  1698     join_aci                ~> sup_aci
  1699     le_def_meet             ~> le_iff_inf
  1700     le_def_join             ~> le_iff_sup
  1701     join_absorp2            ~> sup_absorb2
  1702     join_absorp1            ~> sup_absorb1
  1703     meet_absorp1            ~> inf_absorb1
  1704     meet_absorp2            ~> inf_absorb2
  1705     meet_join_absorp        ~> inf_sup_absorb
  1706     join_meet_absorp        ~> sup_inf_absorb
  1707     distrib_join_le         ~> distrib_sup_le
  1708     distrib_meet_le         ~> distrib_inf_le
  1709 
  1710     add_meet_distrib_left   ~> add_inf_distrib_left
  1711     add_join_distrib_left   ~> add_sup_distrib_left
  1712     is_join_neg_meet        ~> is_join_neg_inf
  1713     is_meet_neg_join        ~> is_meet_neg_sup
  1714     add_meet_distrib_right  ~> add_inf_distrib_right
  1715     add_join_distrib_right  ~> add_sup_distrib_right
  1716     add_meet_join_distribs  ~> add_sup_inf_distribs
  1717     join_eq_neg_meet        ~> sup_eq_neg_inf
  1718     meet_eq_neg_join        ~> inf_eq_neg_sup
  1719     add_eq_meet_join        ~> add_eq_inf_sup
  1720     meet_0_imp_0            ~> inf_0_imp_0
  1721     join_0_imp_0            ~> sup_0_imp_0
  1722     meet_0_eq_0             ~> inf_0_eq_0
  1723     join_0_eq_0             ~> sup_0_eq_0
  1724     neg_meet_eq_join        ~> neg_inf_eq_sup
  1725     neg_join_eq_meet        ~> neg_sup_eq_inf
  1726     join_eq_if              ~> sup_eq_if
  1727 
  1728     mono_meet               ~> mono_inf
  1729     mono_join               ~> mono_sup
  1730     meet_bool_eq            ~> inf_bool_eq
  1731     join_bool_eq            ~> sup_bool_eq
  1732     meet_fun_eq             ~> inf_fun_eq
  1733     join_fun_eq             ~> sup_fun_eq
  1734     meet_set_eq             ~> inf_set_eq
  1735     join_set_eq             ~> sup_set_eq
  1736     meet1_iff               ~> inf1_iff
  1737     meet2_iff               ~> inf2_iff
  1738     meet1I                  ~> inf1I
  1739     meet2I                  ~> inf2I
  1740     meet1D1                 ~> inf1D1
  1741     meet2D1                 ~> inf2D1
  1742     meet1D2                 ~> inf1D2
  1743     meet2D2                 ~> inf2D2
  1744     meet1E                  ~> inf1E
  1745     meet2E                  ~> inf2E
  1746     join1_iff               ~> sup1_iff
  1747     join2_iff               ~> sup2_iff
  1748     join1I1                 ~> sup1I1
  1749     join2I1                 ~> sup2I1
  1750     join1I1                 ~> sup1I1
  1751     join2I2                 ~> sup1I2
  1752     join1CI                 ~> sup1CI
  1753     join2CI                 ~> sup2CI
  1754     join1E                  ~> sup1E
  1755     join2E                  ~> sup2E
  1756 
  1757     is_meet_Meet            ~> is_meet_Inf
  1758     Meet_bool_def           ~> Inf_bool_def
  1759     Meet_fun_def            ~> Inf_fun_def
  1760     Meet_greatest           ~> Inf_greatest
  1761     Meet_lower              ~> Inf_lower
  1762     Meet_set_def            ~> Inf_set_def
  1763 
  1764     Sup_def                 ~> Sup_Inf
  1765     Sup_bool_eq             ~> Sup_bool_def
  1766     Sup_fun_eq              ~> Sup_fun_def
  1767     Sup_set_eq              ~> Sup_set_def
  1768 
  1769     listsp_meetI            ~> listsp_infI
  1770     listsp_meet_eq          ~> listsp_inf_eq
  1771 
  1772     meet_min                ~> inf_min
  1773     join_max                ~> sup_max
  1774 
  1775 * Added syntactic class "size"; overloaded constant "size" now has
  1776 type "'a::size ==> bool"
  1777 
  1778 * Internal reorganisation of `size' of datatypes: size theorems
  1779 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1780 simplification rules by default!); theorems "prod.size" now named
  1781 "*.size".
  1782 
  1783 * Class "div" now inherits from class "times" rather than "type".
  1784 INCOMPATIBILITY.
  1785 
  1786 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1787 Linorder etc.  have disappeared; operations defined in terms of
  1788 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1789 
  1790 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1791 
  1792 * HOL-Word: New extensive library and type for generic, fixed size
  1793 machine words, with arithemtic, bit-wise, shifting and rotating
  1794 operations, reflection into int, nat, and bool lists, automation for
  1795 linear arithmetic (by automatic reflection into nat or int), including
  1796 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1797 arithmetic type classes, supporting automatic simplification of
  1798 numerals on all operations.
  1799 
  1800 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1801 
  1802 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1803 
  1804 * Code generator library theories:
  1805   - Code_Integer represents HOL integers by big integer literals in target
  1806     languages.
  1807   - Code_Char represents HOL characters by character literals in target
  1808     languages.
  1809   - Code_Char_chr like Code_Char, but also offers treatment of character
  1810     codes; includes Code_Integer.
  1811   - Executable_Set allows to generate code for finite sets using lists.
  1812   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1813     denominator).
  1814   - Executable_Real implements a subset of real numbers, namly those
  1815     representable by rational numbers.
  1816   - Efficient_Nat implements natural numbers by integers, which in general will
  1817     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1818     includes Code_Integer.
  1819   - Code_Index provides an additional datatype index which is mapped to
  1820     target-language built-in integers.
  1821   - Code_Message provides an additional datatype message_string which is isomorphic to
  1822     strings; messages are mapped to target-language strings.
  1823 
  1824 * New package for inductive predicates
  1825 
  1826   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  1827 
  1828     inductive
  1829       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1830       for z_1 :: U_1 and ... and z_n :: U_m
  1831     where
  1832       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1833     | ...
  1834 
  1835   with full support for type-inference, rather than
  1836 
  1837     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1838 
  1839     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1840     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1841 
  1842     inductive "s z_1 ... z_m"
  1843     intros
  1844       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1845       ...
  1846 
  1847   For backward compatibility, there is a wrapper allowing inductive
  1848   sets to be defined with the new package via
  1849 
  1850     inductive_set
  1851       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1852       for z_1 :: U_1 and ... and z_n :: U_m
  1853     where
  1854       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  1855     | ...
  1856 
  1857   or
  1858 
  1859     inductive_set
  1860       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  1861       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  1862       for z_1 :: U_1 and ... and z_n :: U_m
  1863     where
  1864       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  1865     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  1866     | ...
  1867 
  1868   if the additional syntax "p ..." is required.
  1869 
  1870   Numerous examples can be found in the subdirectories src/HOL/Auth,
  1871   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  1872 
  1873   INCOMPATIBILITIES:
  1874 
  1875   - Since declaration and definition of inductive sets or predicates
  1876     is no longer separated, abbreviations involving the newly
  1877     introduced sets or predicates must be specified together with the
  1878     introduction rules after the 'where' keyword (see above), rather
  1879     than before the actual inductive definition.
  1880 
  1881   - The variables in induction and elimination rules are now
  1882     quantified in the order of their occurrence in the introduction
  1883     rules, rather than in alphabetical order. Since this may break
  1884     some proofs, these proofs either have to be repaired, e.g. by
  1885     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  1886     statements of the form
  1887 
  1888       case (rule_i a_i_1 ... a_i_{k_i})
  1889 
  1890     or the old order of quantification has to be restored by explicitly adding
  1891     meta-level quantifiers in the introduction rules, i.e.
  1892 
  1893       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  1894 
  1895   - The format of the elimination rules is now
  1896 
  1897       p z_1 ... z_m x_1 ... x_n ==>
  1898         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1899         ==> ... ==> P
  1900 
  1901     for predicates and
  1902 
  1903       (x_1, ..., x_n) : s z_1 ... z_m ==>
  1904         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  1905         ==> ... ==> P
  1906 
  1907     for sets rather than
  1908 
  1909       x : s z_1 ... z_m ==>
  1910         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  1911         ==> ... ==> P
  1912 
  1913     This may require terms in goals to be expanded to n-tuples
  1914     (e.g. using case_tac or simplification with the split_paired_all
  1915     rule) before the above elimination rule is applicable.
  1916 
  1917   - The elimination or case analysis rules for (mutually) inductive
  1918     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  1919     list of rules "p_1_..._p_k.elims" is no longer available.
  1920 
  1921 * New package "function"/"fun" for general recursive functions,
  1922 supporting mutual and nested recursion, definitions in local contexts,
  1923 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  1924 for small examples, and the separate tutorial on the function
  1925 package. The old recdef "package" is still available as before, but
  1926 users are encouraged to use the new package.
  1927 
  1928 * Method "lexicographic_order" automatically synthesizes termination
  1929 relations as lexicographic combinations of size measures. 
  1930 
  1931 * Case-expressions allow arbitrary constructor-patterns (including
  1932 "_") and take their order into account, like in functional
  1933 programming.  Internally, this is translated into nested
  1934 case-expressions; missing cases are added and mapped to the predefined
  1935 constant "undefined". In complicated cases printing may no longer show
  1936 the original input but the internal form. Lambda-abstractions allow
  1937 the same form of pattern matching: "% pat1 => e1 | ..." is an
  1938 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  1939 variable.
  1940 
  1941 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  1942 is an abbreviation for "of_nat :: nat => int". The simplification
  1943 rules for "of_nat" have been changed to work like "int" did
  1944 previously.  Potential INCOMPATIBILITY:
  1945   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  1946   - of_nat_diff and of_nat_mult are no longer default simp rules
  1947 
  1948 * Method "algebra" solves polynomial equations over (semi)rings using
  1949 Groebner bases. The (semi)ring structure is defined by locales and the
  1950 tool setup depends on that generic context. Installing the method for
  1951 a specific type involves instantiating the locale and possibly adding
  1952 declarations for computation on the coefficients.  The method is
  1953 already instantiated for natural numbers and for the axiomatic class
  1954 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  1955 CALCULEMUS 2007 for the general principles underlying this
  1956 architecture of context-aware proof-tools.
  1957 
  1958 * Method "ferrack" implements quantifier elimination over
  1959 special-purpose dense linear orders using locales (analogous to
  1960 "algebra"). The method is already installed for class
  1961 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  1962 rat, etc.
  1963 
  1964 * Former constant "List.op @" now named "List.append".  Use ML
  1965 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1966 circumvent possible incompatibilities when working on ML level.
  1967 
  1968 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1969 
  1970 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1971 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1972 
  1973 * New syntax for Haskell-like list comprehension (input only), eg.
  1974 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1975 
  1976 * The special syntax for function "filter" has changed from [x :
  1977 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1978 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1979 
  1980 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1981 defined on nat only, as an abbreviation for [a..<Suc b]
  1982 INCOMPATIBILITY.
  1983 
  1984 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1985 
  1986 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1987 
  1988 * New lemma collection field_simps (an extension of ring_simps) for
  1989 manipulating (in)equations involving division. Multiplies with all
  1990 denominators that can be proved to be non-zero (in equations) or
  1991 positive/negative (in inequations).
  1992 
  1993 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1994 have been improved and renamed to ring_simps, group_simps and
  1995 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1996 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1997 
  1998 * Theory Library/Commutative_Ring: switched from recdef to function
  1999 package; constants add, mul, pow now curried.  Infix syntax for
  2000 algebraic operations.
  2001 
  2002 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2003 INCOMPATIBILITY.
  2004 
  2005 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2006 INCOMPATIBILITY.
  2007 
  2008 * HOL/records: generalised field-update to take a function on the
  2009 field rather than the new value: r(|A := x|) is translated to A_update
  2010 (K x) r The K-combinator that is internally used is called K_record.
  2011 INCOMPATIBILITY: Usage of the plain update functions has to be
  2012 adapted.
  2013  
  2014 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2015 * x = 0, which are required for a semiring.  Richer structures do not
  2016 inherit from semiring_0 anymore, because this property is a theorem
  2017 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2018 there is more to prove, but this is mostly trivial.
  2019 
  2020 * Class "recpower" is generalized to arbitrary monoids, not just
  2021 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2022 commutativity or semiring properties additionally.
  2023 
  2024 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2025 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2026 better use 'abbreviation'.
  2027 
  2028 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2029 
  2030 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2031 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2032 significant changes for setting up numeral syntax for types:
  2033   - New constants Numeral.pred and Numeral.succ instead
  2034       of former Numeral.bin_pred and Numeral.bin_succ.
  2035   - Use integer operations instead of bin_add, bin_mult and so on.
  2036   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2037   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2038 
  2039 See src/HOL/Integ/IntArith.thy for an example setup.
  2040 
  2041 * Command 'normal_form' computes the normal form of a term that may
  2042 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2043 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2044 heavy-duty computations because the functions are compiled to ML
  2045 first.  Correspondingly, a method "normalization" is provided.  See
  2046 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2047 
  2048 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2049 25 like -->); output depends on the "iff" print_mode, the default is
  2050 "A = B" (with priority 50).
  2051 
  2052 * Relations less (<) and less_eq (<=) are also available on type bool.
  2053 Modified syntax to disallow nesting without explicit parentheses,
  2054 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2055 INCOMPATIBILITY.
  2056 
  2057 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2058 
  2059 * Relation composition operator "op O" now has precedence 75 and binds
  2060 stronger than union and intersection. INCOMPATIBILITY.
  2061 
  2062 * The old set interval syntax "{m..n(}" (and relatives) has been
  2063 removed.  Use "{m..<n}" (and relatives) instead.
  2064 
  2065 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2066 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2067 ``declare [[simproc del: neq]]''.
  2068 
  2069 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2070 True/False.
  2071 
  2072 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2073 
  2074 * Theorem setsum_mult renamed to setsum_right_distrib.
  2075 
  2076 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2077 ``rule'' method.
  2078 
  2079 * Reimplemented methods "sat" and "satx", with several improvements:
  2080 goals no longer need to be stated as "<prems> ==> False", equivalences
  2081 (i.e. "=" on type bool) are handled, variable names of the form
  2082 "lit_<n>" are no longer reserved, significant speedup.
  2083 
  2084 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2085 zChaff is still supported as well.
  2086 
  2087 * 'inductive' and 'datatype': provide projections of mutual rules,
  2088 bundled as foo_bar.inducts;
  2089 
  2090 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2091 Library.
  2092 
  2093 * Library: moved theory Accessible_Part to main HOL.
  2094 
  2095 * Library: added theory Coinductive_List of potentially infinite lists
  2096 as greatest fixed-point.
  2097 
  2098 * Library: added theory AssocList which implements (finite) maps as
  2099 association lists.
  2100 
  2101 * Method "evaluation" solves goals (i.e. a boolean expression)
  2102 efficiently by compiling it to ML.  The goal is "proved" (via an
  2103 oracle) if it evaluates to True.
  2104 
  2105 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2106 also when invoked by the simplifier.  This results in the Simplifier
  2107 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2108 Configuration option fast_arith_split_limit=0 recovers the old
  2109 behavior.
  2110 
  2111 * Support for hex (0x20) and binary (0b1001) numerals.
  2112 
  2113 * New method: reify eqs (t), where eqs are equations for an
  2114 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2115 parameter, computes a term s::'b and a list xs::'a list and proves the
  2116 theorem I xs s = t. This is also known as reification or quoting. The
  2117 resulting theorem is applied to the subgoal to substitute t with I xs
  2118 s.  If t is omitted, the subgoal itself is reified.
  2119 
  2120 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2121 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2122 where f is supposed to be a computable function (in the sense of code
  2123 generattion). The method uses reify to compute s and xs as above then
  2124 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2125 r and finally gets the theorem t = r, which is again applied to the
  2126 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2127 
  2128 * Reflection: Automatic reification now handels binding, an example is
  2129 available in src/HOL/ex/ReflectionEx.thy
  2130 
  2131 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2132 command 'statespace' that is similar to 'record', but introduces an
  2133 abstract specification based on the locale infrastructure instead of
  2134 HOL types.  This leads to extra flexibility in composing state spaces,
  2135 in particular multiple inheritance and renaming of components.
  2136 
  2137 
  2138 *** HOL-Complex ***
  2139 
  2140 * Hyperreal: Functions root and sqrt are now defined on negative real
  2141 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2142 Nonnegativity side conditions have been removed from many lemmas, so
  2143 that more subgoals may now be solved by simplification; potential
  2144 INCOMPATIBILITY.
  2145 
  2146 * Real: new type classes formalize real normed vector spaces and
  2147 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2148 and norm :: 'a => real.
  2149 
  2150 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2151 reals into other types. The overloaded constant Reals :: 'a set is now
  2152 defined as range of_real; potential INCOMPATIBILITY.
  2153 
  2154 * Real: proper support for ML code generation, including 'quickcheck'.
  2155 Reals are implemented as arbitrary precision rationals.
  2156 
  2157 * Hyperreal: Several constants that previously worked only for the
  2158 reals have been generalized, so they now work over arbitrary vector
  2159 spaces. Type annotations may need to be added in some cases; potential
  2160 INCOMPATIBILITY.
  2161 
  2162   Infinitesimal  :: ('a::real_normed_vector) star set
  2163   HFinite        :: ('a::real_normed_vector) star set
  2164   HInfinite      :: ('a::real_normed_vector) star set
  2165   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2166   monad          :: ('a::real_normed_vector) star => 'a star set
  2167   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2168   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2169   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2170   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2171   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2172   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2173   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2174   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2175   sgn            :: 'a::real_normed_vector => 'a
  2176   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2177 
  2178 * Complex: Some complex-specific constants are now abbreviations for
  2179 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2180 hnorm.  Other constants have been entirely removed in favor of the
  2181 polymorphic versions (INCOMPATIBILITY):
  2182 
  2183   approx        <-- capprox
  2184   HFinite       <-- CFinite
  2185   HInfinite     <-- CInfinite
  2186   Infinitesimal <-- CInfinitesimal
  2187   monad         <-- cmonad
  2188   galaxy        <-- cgalaxy
  2189   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2190   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2191   (ns)deriv     <-- (ns)cderiv
  2192 
  2193 
  2194 *** HOL-Algebra ***
  2195 
  2196 * Formalisation of ideals and the quotient construction over rings.
  2197 
  2198 * Order and lattice theory no longer based on records.
  2199 INCOMPATIBILITY.
  2200 
  2201 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2202 greatest_closed.  INCOMPATIBILITY.
  2203 
  2204 * Method algebra is now set up via an attribute.  For examples see
  2205 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2206 of algebraic structures.
  2207 
  2208 * Renamed theory CRing to Ring.
  2209 
  2210 
  2211 *** HOL-Nominal ***
  2212 
  2213 * Substantial, yet incomplete support for nominal datatypes (binding
  2214 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2215 src/HOL/Nominal/Examples.  Prospective users should consult
  2216 http://isabelle.in.tum.de/nominal/
  2217 
  2218 
  2219 *** ML ***
  2220 
  2221 * ML basics: just one true type int, which coincides with IntInf.int
  2222 (even on SML/NJ).
  2223 
  2224 * ML within Isar: antiquotations allow to embed statically-checked
  2225 formal entities in the source, referring to the context available at
  2226 compile-time.  For example:
  2227 
  2228 ML {* @{sort "{zero,one}"} *}
  2229 ML {* @{typ "'a => 'b"} *}
  2230 ML {* @{term "%x. x"} *}
  2231 ML {* @{prop "x == y"} *}
  2232 ML {* @{ctyp "'a => 'b"} *}
  2233 ML {* @{cterm "%x. x"} *}
  2234 ML {* @{cprop "x == y"} *}
  2235 ML {* @{thm asm_rl} *}
  2236 ML {* @{thms asm_rl} *}
  2237 ML {* @{type_name c} *}
  2238 ML {* @{type_syntax c} *}
  2239 ML {* @{const_name c} *}
  2240 ML {* @{const_syntax c} *}
  2241 ML {* @{context} *}
  2242 ML {* @{theory} *}
  2243 ML {* @{theory Pure} *}
  2244 ML {* @{theory_ref} *}
  2245 ML {* @{theory_ref Pure} *}
  2246 ML {* @{simpset} *}
  2247 ML {* @{claset} *}
  2248 ML {* @{clasimpset} *}
  2249 
  2250 The same works for sources being ``used'' within an Isar context.
  2251 
  2252 * ML in Isar: improved error reporting; extra verbosity with
  2253 ML_Context.trace enabled.
  2254 
  2255 * Pure/General/table.ML: the join operations now works via exceptions
  2256 DUP/SAME instead of type option. This is simpler in simple cases, and
  2257 admits slightly more efficient complex applications.
  2258 
  2259 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2260 use Context.generic instead of just theory.
  2261 
  2262 * Pure: datatype Context.generic joins theory/Proof.context and
  2263 provides some facilities for code that works in either kind of
  2264 context, notably GenericDataFun for uniform theory and proof data.
  2265 
  2266 * Pure: simplified internal attribute type, which is now always
  2267 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2268 local (Proof.context) attributes have been discontinued, while
  2269 minimizing code duplication. Thm.rule_attribute and
  2270 Thm.declaration_attribute build canonical attributes; see also structure
  2271 Context for further operations on Context.generic, notably
  2272 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2273 declarations and definitions.
  2274 
  2275 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2276 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2277 init only required for impure data. INCOMPATIBILITY: empty really need
  2278 to be empty (no dependencies on theory content!)
  2279 
  2280 * Pure/kernel: consts certification ignores sort constraints given in
  2281 signature declarations. (This information is not relevant to the
  2282 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2283 potential INCOMPATIBILITY.
  2284 
  2285 * Pure: axiomatic type classes are now purely definitional, with
  2286 explicit proofs of class axioms and super class relations performed
  2287 internally. See Pure/axclass.ML for the main internal interfaces --
  2288 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2289 AxClass.axiomatize_class/classrel/arity supersede
  2290 Sign.add_classes/classrel/arities.
  2291 
  2292 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2293 global/local versions on theory vs. Proof.context have been
  2294 discontinued; Attrib.syntax and Method.syntax have been adapted
  2295 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2296 attributes, methods, etc.
  2297 
  2298 * Pure: several functions of signature "... -> theory -> theory * ..."
  2299 have been reoriented to "... -> theory -> ... * theory" in order to
  2300 allow natural usage in combination with the ||>, ||>>, |-> and
  2301 fold_map combinators.
  2302 
  2303 * Pure: official theorem names (closed derivations) and additional
  2304 comments (tags) are now strictly separate.  Name hints -- which are
  2305 maintained as tags -- may be attached any time without affecting the
  2306 derivation.
  2307 
  2308 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2309 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2310 achieve the old behaviour.
  2311 
  2312 * Pure: the "Goal" constant is now called "prop", supporting a
  2313 slightly more general idea of ``protecting'' meta-level rule
  2314 statements.
  2315 
  2316 * Pure: Logic.(un)varify only works in a global context, which is now
  2317 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2318 Logic.legacy_(un)varify as temporary workaround.
  2319 
  2320 * Pure: structure Name provides scalable operations for generating
  2321 internal variable names, notably Name.variants etc.  This replaces
  2322 some popular functions from term.ML:
  2323 
  2324   Term.variant		->  Name.variant
  2325   Term.variantlist	->  Name.variant_list
  2326   Term.invent_names	->  Name.invent_list
  2327 
  2328 Note that low-level renaming rarely occurs in new code -- operations
  2329 from structure Variable are used instead (see below).
  2330 
  2331 * Pure: structure Variable provides fundamental operations for proper
  2332 treatment of fixed/schematic variables in a context.  For example,
  2333 Variable.import introduces fixes for schematics of given facts and
  2334 Variable.export reverses the effect (up to renaming) -- this replaces
  2335 various freeze_thaw operations.
  2336 
  2337 * Pure: structure Goal provides simple interfaces for
  2338 init/conclude/finish and tactical prove operations (replacing former
  2339 Tactic.prove).  Goal.prove is the canonical way to prove results
  2340 within a given context; Goal.prove_global is a degraded version for
  2341 theory level goals, including a global Drule.standard.  Note that
  2342 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2343 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2344 in a locale context).
  2345 
  2346 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2347 and type checking (Syntax.check_term etc.), with common combinations
  2348 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2349 which are considered legacy and await removal.
  2350 
  2351 * Pure/Syntax: generic interfaces for type unchecking
  2352 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2353 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2354 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2355 available for convenience, but refer to the very same operations using
  2356 a mere theory instead of a full context.
  2357 
  2358 * Isar: simplified treatment of user-level errors, using exception
  2359 ERROR of string uniformly.  Function error now merely raises ERROR,
  2360 without any side effect on output channels.  The Isar toplevel takes
  2361 care of proper display of ERROR exceptions.  ML code may use plain
  2362 handle/can/try; cat_error may be used to concatenate errors like this:
  2363 
  2364   ... handle ERROR msg => cat_error msg "..."
  2365 
  2366 Toplevel ML code (run directly or through the Isar toplevel) may be
  2367 embedded into the Isar toplevel with exception display/debug like
  2368 this:
  2369 
  2370   Isar.toplevel (fn () => ...)
  2371 
  2372 INCOMPATIBILITY, removed special transform_error facilities, removed
  2373 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2374 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2375 -- use plain ERROR instead.
  2376 
  2377 * Isar: theory setup now has type (theory -> theory), instead of a
  2378 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2379 
  2380 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2381 ProofContext.debug/verbose flags.
  2382 
  2383 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2384 theory before entering a proof state.  Transactions now always see a
  2385 quasi-functional intermediate checkpoint, both in interactive and
  2386 batch mode.
  2387 
  2388 * Isar: simplified interfaces for outer syntax.  Renamed
  2389 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2390 OuterSyntax.add_parsers -- this functionality is now included in
  2391 OuterSyntax.command etc.  INCOMPATIBILITY.
  2392 
  2393 * Simplifier: the simpset of a running simplification process now
  2394 contains a proof context (cf. Simplifier.the_context), which is the
  2395 very context that the initial simpset has been retrieved from (by
  2396 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2397 (solver, looper etc.) may depend on arbitrary proof data.
  2398 
  2399 * Simplifier.inherit_context inherits the proof context (plus the
  2400 local bounds) of the current simplification process; any simproc
  2401 etc. that calls the Simplifier recursively should do this!  Removed
  2402 former Simplifier.inherit_bounds, which is already included here --
  2403 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2404 specify an explicit context using Simplifier.context/theory_context.
  2405 
  2406 * Simplifier/Classical Reasoner: more abstract interfaces
  2407 change_simpset/claset for modifying the simpset/claset reference of a
  2408 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2409 INCOMPATIBILITY.
  2410 
  2411 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2412 "Trueprop" etc.
  2413 
  2414 
  2415 *** System ***
  2416 
  2417 * settings: the default heap location within ISABELLE_HOME_USER now
  2418 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2419 Isabelle installations.
  2420 
  2421 * isabelle-process: option -S (secure mode) disables some critical
  2422 operations, notably runtime compilation and evaluation of ML source
  2423 code.
  2424 
  2425 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2426 
  2427 * Support for parallel execution, using native multicore support of
  2428 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2429 independent theories, according to the given theory header
  2430 specifications. The maximum number of worker threads is specified via
  2431 usedir option -M or the "max-threads" setting in Proof General. A
  2432 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2433 to 6 on a 8-core machine.  User-code needs to observe certain
  2434 guidelines for thread-safe programming, see appendix A in the Isar
  2435 Implementation manual.
  2436 
  2437 
  2438 
  2439 New in Isabelle2005 (October 2005)
  2440 ----------------------------------
  2441 
  2442 *** General ***
  2443 
  2444 * Theory headers: the new header syntax for Isar theories is
  2445 
  2446   theory <name>
  2447   imports <theory1> ... <theoryN>
  2448   uses <file1> ... <fileM>
  2449   begin
  2450 
  2451 where the 'uses' part is optional.  The previous syntax
  2452 
  2453   theory <name> = <theory1> + ... + <theoryN>:
  2454 
  2455 will disappear in the next release.  Use isatool fixheaders to convert
  2456 existing theory files.  Note that there is no change in ancient
  2457 non-Isar theories now, but these will disappear soon.
  2458 
  2459 * Theory loader: parent theories can now also be referred to via
  2460 relative and absolute paths.
  2461 
  2462 * Command 'find_theorems' searches for a list of criteria instead of a
  2463 list of constants. Known criteria are: intro, elim, dest, name:string,
  2464 simp:term, and any term. Criteria can be preceded by '-' to select
  2465 theorems that do not match. Intro, elim, dest select theorems that
  2466 match the current goal, name:s selects theorems whose fully qualified
  2467 name contain s, and simp:term selects all simplification rules whose
  2468 lhs match term.  Any other term is interpreted as pattern and selects
  2469 all theorems matching the pattern. Available in ProofGeneral under
  2470 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2471 
  2472   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2473 
  2474 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2475 matching the current goal as introduction rule and not having "HOL."
  2476 in their name (i.e. not being defined in theory HOL).
  2477 
  2478 * Command 'thms_containing' has been discontinued in favour of
  2479 'find_theorems'; INCOMPATIBILITY.
  2480 
  2481 * Communication with Proof General is now 8bit clean, which means that
  2482 Unicode text in UTF-8 encoding may be used within theory texts (both
  2483 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2484 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2485 
  2486   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2487   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2488 
  2489 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2490 Classical Reasoner.  Typical big applications run around 2 times
  2491 faster.
  2492 
  2493 
  2494 *** Document preparation ***
  2495 
  2496 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2497 of raw sources.  Only those symbols that do not require additional
  2498 LaTeX packages (depending on comments in isabellesym.sty) are
  2499 displayed properly, everything else is left verbatim.  isatool display
  2500 and isatool print are used as front ends (these are subject to the
  2501 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2502 
  2503 * Command tags control specific markup of certain regions of text,
  2504 notably folding and hiding.  Predefined tags include "theory" (for
  2505 theory begin and end), "proof" for proof commands, and "ML" for
  2506 commands involving ML code; the additional tags "visible" and
  2507 "invisible" are unused by default.  Users may give explicit tag
  2508 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2509 interpretation of tags is determined by the LaTeX job during document
  2510 preparation: see option -V of isatool usedir, or options -n and -t of
  2511 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2512 \isadroptag.
  2513 
  2514 Several document versions may be produced at the same time via isatool
  2515 usedir (the generated index.html will link all of them).  Typical
  2516 specifications include ''-V document=theory,proof,ML'' to present
  2517 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2518 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2519 these parts without any formal replacement text.  The Isabelle site
  2520 default settings produce ''document'' and ''outline'' versions as
  2521 specified above.
  2522 
  2523 * Several new antiquotations:
  2524 
  2525   @{term_type term} prints a term with its type annotated;
  2526 
  2527   @{typeof term} prints the type of a term;
  2528 
  2529   @{const const} is the same as @{term const}, but checks that the
  2530   argument is a known logical constant;
  2531 
  2532   @{term_style style term} and @{thm_style style thm} print a term or
  2533   theorem applying a "style" to it
  2534 
  2535   @{ML text}
  2536 
  2537 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2538 definitions, equations, inequations etc., 'concl' printing only the
  2539 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2540 to print the specified premise.  TermStyle.add_style provides an ML
  2541 interface for introducing further styles.  See also the "LaTeX Sugar"
  2542 document practical applications.  The ML antiquotation prints
  2543 type-checked ML expressions verbatim.
  2544 
  2545 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2546 and 'text' support optional locale specification '(in loc)', which
  2547 specifies the default context for interpreting antiquotations.  For
  2548 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2549 
  2550 * Option 'locale=NAME' of antiquotations specifies an alternative
  2551 context interpreting the subsequent argument.  For example: @{thm
  2552 [locale=lattice] inf_assoc}.
  2553 
  2554 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2555 a proof context.
  2556 
  2557 * Proper output of antiquotations for theory commands involving a
  2558 proof context (such as 'locale' or 'theorem (in loc) ...').
  2559 
  2560 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2561 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2562 
  2563 * isatool usedir: new option -C (default true) controls whether option
  2564 -D should include a copy of the original document directory; -C false
  2565 prevents unwanted effects such as copying of administrative CVS data.
  2566 
  2567 
  2568 *** Pure ***
  2569 
  2570 * Considerably improved version of 'constdefs' command.  Now performs
  2571 automatic type-inference of declared constants; additional support for
  2572 local structure declarations (cf. locales and HOL records), see also
  2573 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2574 sequential dependencies of definitions within a single 'constdefs'
  2575 section; moreover, the declared name needs to be an identifier.  If
  2576 all fails, consider to fall back on 'consts' and 'defs' separately.
  2577 
  2578 * Improved indexed syntax and implicit structures.  First of all,
  2579 indexed syntax provides a notational device for subscripted
  2580 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2581 expressions.  Secondly, in a local context with structure
  2582 declarations, number indexes \<^sub>n or the empty index (default
  2583 number 1) refer to a certain fixed variable implicitly; option
  2584 show_structs controls printing of implicit structures.  Typical
  2585 applications of these concepts involve record types and locales.
  2586 
  2587 * New command 'no_syntax' removes grammar declarations (and
  2588 translations) resulting from the given syntax specification, which is
  2589 interpreted in the same manner as for the 'syntax' command.
  2590 
  2591 * 'Advanced' translation functions (parse_translation etc.) may depend
  2592 on the signature of the theory context being presently used for
  2593 parsing/printing, see also isar-ref manual.
  2594 
  2595 * Improved 'oracle' command provides a type-safe interface to turn an
  2596 ML expression of type theory -> T -> term into a primitive rule of
  2597 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2598 is already included here); see also FOL/ex/IffExample.thy;
  2599 INCOMPATIBILITY.
  2600 
  2601 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2602 before); "cI" is no longer bound, use "c.intro" instead.
  2603 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2604 axclasses vs. locales.
  2605 
  2606 * Improved internal renaming of symbolic identifiers -- attach primes
  2607 instead of base 26 numbers.
  2608 
  2609 * New flag show_question_marks controls printing of leading question
  2610 marks in schematic variable names.
  2611 
  2612 * In schematic variable names, *any* symbol following \<^isub> or
  2613 \<^isup> is now treated as part of the base name.  For example, the
  2614 following works without printing of awkward ".0" indexes:
  2615 
  2616   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2617     by simp
  2618 
  2619 * Inner syntax includes (*(*nested*) comments*).
  2620 
  2621 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2622 annotations as "(00...)".
  2623 
  2624 * Clear separation of logical types and nonterminals, where the latter
  2625 may only occur in 'syntax' specifications or type abbreviations.
  2626 Before that distinction was only partially implemented via type class
  2627 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2628 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2629 exotic syntax specifications may require further adaption
  2630 (e.g. Cube/Cube.thy).
  2631 
  2632 * Removed obsolete type class "logic", use the top sort {} instead.
  2633 Note that non-logical types should be declared as 'nonterminals'
  2634 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2635 specifications.
  2636 
  2637 * Attributes 'induct' and 'cases': type or set names may now be
  2638 locally fixed variables as well.
  2639 
  2640 * Simplifier: can now control the depth to which conditional rewriting
  2641 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2642 Limit.
  2643 
  2644 * Simplifier: simplification procedures may now take the current
  2645 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2646 interface), which is very useful for calling the Simplifier
  2647 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2648 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2649 low-level mk_simproc no longer applies Logic.varify internally, to
  2650 allow for use in a context of fixed variables.
  2651 
  2652 * thin_tac now works even if the assumption being deleted contains !!
  2653 or ==>.  More generally, erule now works even if the major premise of
  2654 the elimination rule contains !! or ==>.
  2655 
  2656 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2657 
  2658 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2659 from Pure, which contains all common declarations already.  Both
  2660 theories are defined via plain Isabelle/Isar .thy files.
  2661 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2662 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2663 use isatool fixcpure to adapt your theory and ML sources.
  2664 
  2665 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2666 selections of theorems in named facts via index ranges.
  2667 
  2668 * 'print_theorems': in theory mode, really print the difference
  2669 wrt. the last state (works for interactive theory development only),
  2670 in proof mode print all local facts (cf. 'print_facts');
  2671 
  2672 * 'hide': option '(open)' hides only base names.
  2673 
  2674 * More efficient treatment of intermediate checkpoints in interactive
  2675 theory development.
  2676 
  2677 * Code generator is now invoked via code_module (incremental code
  2678 generation) and code_library (modular code generation, ML structures
  2679 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2680 must be quoted when used as identifiers.
  2681 
  2682 * New 'value' command for reading, evaluating and printing terms using
  2683 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2684 quoted when used as identifier.
  2685 
  2686 
  2687 *** Locales ***
  2688 
  2689 * New commands for the interpretation of locale expressions in
  2690 theories (1), locales (2) and proof contexts (3).  These generate
  2691 proof obligations from the expression specification.  After the
  2692 obligations have been discharged, theorems of the expression are added
  2693 to the theory, target locale or proof context.  The synopsis of the
  2694 commands is a follows:
  2695 
  2696   (1) interpretation expr inst
  2697   (2) interpretation target < expr
  2698   (3) interpret expr inst
  2699 
  2700 Interpretation in theories and proof contexts require a parameter
  2701 instantiation of terms from the current context.  This is applied to
  2702 specifications and theorems of the interpreted expression.
  2703 Interpretation in locales only permits parameter renaming through the
  2704 locale expression.  Interpretation is smart in that interpretations
  2705 that are active already do not occur in proof obligations, neither are
  2706 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2707 inspect active interpretations of a particular locale.  For details,
  2708 see the Isar Reference manual.  Examples can be found in
  2709 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2710 
  2711 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2712 'interpret' instead.
  2713 
  2714 * New context element 'constrains' for adding type constraints to
  2715 parameters.
  2716 
  2717 * Context expressions: renaming of parameters with syntax
  2718 redeclaration.
  2719 
  2720 * Locale declaration: 'includes' disallowed.
  2721 
  2722 * Proper static binding of attribute syntax -- i.e. types / terms /
  2723 facts mentioned as arguments are always those of the locale definition
  2724 context, independently of the context of later invocations.  Moreover,
  2725 locale operations (renaming and type / term instantiation) are applied
  2726 to attribute arguments as expected.
  2727 
  2728 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2729 actual attributes; rare situations may require Attrib.attribute to
  2730 embed those attributes into Attrib.src that lack concrete syntax.
  2731 Attribute implementations need to cooperate properly with the static
  2732 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2733 Attrib.XXX_thm etc. already do the right thing without further
  2734 intervention.  Only unusual applications -- such as "where" or "of"
  2735 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2736 on the context and the facts involved -- may have to assign parsed
  2737 values to argument tokens explicitly.
  2738 
  2739 * Changed parameter management in theorem generation for long goal
  2740 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2741 theorem statement in rare situations.
  2742 
  2743 * Locale inspection command 'print_locale' omits notes elements.  Use
  2744 'print_locale!' to have them included in the output.
  2745 
  2746 
  2747 *** Provers ***
  2748 
  2749 * Provers/hypsubst.ML: improved version of the subst method, for
  2750 single-step rewriting: it now works in bound variable contexts. New is
  2751 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2752 rewrite a different subterm than the original subst method, which is
  2753 still available as 'simplesubst'.
  2754 
  2755 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2756 and quasi orders.
  2757 
  2758 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2759 reflexive-transitive closure of relations.
  2760 
  2761 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2762 limit (previously hard-coded with a value of 20) user-definable.
  2763 
  2764 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2765 is peformed already.  Object-logics merely need to finish their
  2766 initial simpset configuration as before.  INCOMPATIBILITY.
  2767 
  2768 
  2769 *** HOL ***
  2770 
  2771 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2772 
  2773   syntax (epsilon)
  2774     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2775 
  2776 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2777 and x-symbol; use option '-m epsilon' to get it actually printed.
  2778 Moreover, the mathematically important symbolic identifier \<epsilon>
  2779 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2780 
  2781 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2782 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2783 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2784 support corresponding Isar calculations.
  2785 
  2786 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2787 instead of ":".
  2788 
  2789 * theory SetInterval: changed the syntax for open intervals:
  2790 
  2791   Old       New
  2792   {..n(}    {..<n}
  2793   {)n..}    {n<..}
  2794   {m..n(}   {m..<n}
  2795   {)m..n}   {m<..n}
  2796   {)m..n(}  {m<..<n}
  2797 
  2798 The old syntax is still supported but will disappear in the next
  2799 release.  For conversion use the following Emacs search and replace
  2800 patterns (these are not perfect but work quite well):
  2801 
  2802   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2803   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2804 
  2805 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2806 equalities in commutative rings; method 'algebra' provides a generic
  2807 interface.
  2808 
  2809 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2810 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2811 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2812 be a tuple pattern.
  2813 
  2814 Some new syntax forms are available:
  2815 
  2816   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2817   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2818   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2819   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2820 
  2821 The latter form "\<Sum>x < k. e" used to be based on a separate
  2822 function "Summation", which has been discontinued.
  2823 
  2824 * theory Finite_Set: in structured induction proofs, the insert case
  2825 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2826 (insert F x)'.
  2827 
  2828 * The 'refute' command has been extended to support a much larger
  2829 fragment of HOL, including axiomatic type classes, constdefs and
  2830 typedefs, inductive datatypes and recursion.
  2831 
  2832 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  2833 Requires zChaff with proof generation to be installed.  See
  2834 HOL/ex/SAT_Examples.thy for examples.
  2835 
  2836 * Datatype induction via method 'induct' now preserves the name of the
  2837 induction variable. For example, when proving P(xs::'a list) by
  2838 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  2839 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  2840 in unstructured proof scripts.
  2841 
  2842 * Reworked implementation of records.  Improved scalability for
  2843 records with many fields, avoiding performance problems for type
  2844 inference. Records are no longer composed of nested field types, but
  2845 of nested extension types. Therefore the record type only grows linear
  2846 in the number of extensions and not in the number of fields.  The
  2847 top-level (users) view on records is preserved.  Potential
  2848 INCOMPATIBILITY only in strange cases, where the theory depends on the
  2849 old record representation. The type generated for a record is called
  2850 <record_name>_ext_type.
  2851 
  2852 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  2853 proofs triggered by a record definition or a simproc (if
  2854 quick_and_dirty is enabled).  Definitions of large records can take
  2855 quite long.
  2856 
  2857 New simproc record_upd_simproc for simplification of multiple record
  2858 updates enabled by default.  Moreover, trivial updates are also
  2859 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  2860 occasionally, since simplification is more powerful by default.
  2861 
  2862 * typedef: proper support for polymorphic sets, which contain extra
  2863 type-variables in the term.
  2864 
  2865 * Simplifier: automatically reasons about transitivity chains
  2866 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  2867 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  2868 old proofs break occasionally as simplification may now solve more
  2869 goals than previously.
  2870 
  2871 * Simplifier: converts x <= y into x = y if assumption y <= x is
  2872 present.  Works for all partial orders (class "order"), in particular
  2873 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  2874 just like y <= x.
  2875 
  2876 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  2877 bound variable or a constant then the let is unfolded.  Otherwise
  2878 first a is simplified to b, and then f b is simplified to g. If
  2879 possible we abstract b from g arriving at "let x = b in h x",
  2880 otherwise we unfold the let and arrive at g.  The simproc can be
  2881 enabled/disabled by the reference use_let_simproc.  Potential
  2882 INCOMPATIBILITY since simplification is more powerful by default.
  2883 
  2884 * Classical reasoning: the meson method now accepts theorems as arguments.
  2885 
  2886 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  2887 jobs to provide advice on the provability of subgoals.
  2888 
  2889 * Theory OrderedGroup and Ring_and_Field: various additions and
  2890 improvements to faciliate calculations involving equalities and
  2891 inequalities.
  2892 
  2893 The following theorems have been eliminated or modified
  2894 (INCOMPATIBILITY):
  2895 
  2896   abs_eq             now named abs_of_nonneg
  2897   abs_of_ge_0        now named abs_of_nonneg
  2898   abs_minus_eq       now named abs_of_nonpos
  2899   imp_abs_id         now named abs_of_nonneg
  2900   imp_abs_neg_id     now named abs_of_nonpos
  2901   mult_pos           now named mult_pos_pos
  2902   mult_pos_le        now named mult_nonneg_nonneg
  2903   mult_pos_neg_le    now named mult_nonneg_nonpos
  2904   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  2905   mult_neg           now named mult_neg_neg
  2906   mult_neg_le        now named mult_nonpos_nonpos
  2907 
  2908 * The following lemmas in Ring_and_Field have been added to the simplifier:
  2909      
  2910      zero_le_square
  2911      not_square_less_zero 
  2912 
  2913   The following lemmas have been deleted from Real/RealPow:
  2914   
  2915      realpow_zero_zero
  2916      realpow_two
  2917      realpow_less
  2918      zero_le_power
  2919      realpow_two_le
  2920      abs_realpow_two
  2921      realpow_two_abs     
  2922 
  2923 * Theory Parity: added rules for simplifying exponents.
  2924 
  2925 * Theory List:
  2926 
  2927 The following theorems have been eliminated or modified
  2928 (INCOMPATIBILITY):
  2929 
  2930   list_all_Nil       now named list_all.simps(1)
  2931   list_all_Cons      now named list_all.simps(2)
  2932   list_all_conv      now named list_all_iff
  2933   set_mem_eq         now named mem_iff
  2934 
  2935 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  2936 asymptotic "big O" calculations.  See the notes in BigO.thy.
  2937 
  2938 
  2939 *** HOL-Complex ***
  2940 
  2941 * Theory RealDef: better support for embedding natural numbers and
  2942 integers in the reals.
  2943 
  2944 The following theorems have been eliminated or modified
  2945 (INCOMPATIBILITY):
  2946 
  2947   exp_ge_add_one_self  now requires no hypotheses
  2948   real_of_int_add      reversed direction of equality (use [symmetric])
  2949   real_of_int_minus    reversed direction of equality (use [symmetric])
  2950   real_of_int_diff     reversed direction of equality (use [symmetric])
  2951   real_of_int_mult     reversed direction of equality (use [symmetric])
  2952 
  2953 * Theory RComplete: expanded support for floor and ceiling functions.
  2954 
  2955 * Theory Ln is new, with properties of the natural logarithm
  2956 
  2957 * Hyperreal: There is a new type constructor "star" for making
  2958 nonstandard types.  The old type names are now type synonyms:
  2959 
  2960   hypreal = real star
  2961   hypnat = nat star
  2962   hcomplex = complex star
  2963 
  2964 * Hyperreal: Many groups of similarly-defined constants have been
  2965 replaced by polymorphic versions (INCOMPATIBILITY):
  2966 
  2967   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2968 
  2969   starset      <-- starsetNat, starsetC
  2970   *s*          <-- *sNat*, *sc*
  2971   starset_n    <-- starsetNat_n, starsetC_n
  2972   *sn*         <-- *sNatn*, *scn*
  2973   InternalSets <-- InternalNatSets, InternalCSets
  2974 
  2975   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2976   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2977   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2978   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2979   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2980 
  2981 * Hyperreal: Many type-specific theorems have been removed in favor of
  2982 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2983 
  2984   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2985   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2986   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2987   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2988   right_minus <-- hypreal_add_minus
  2989   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2990   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2991   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2992   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2993   mult_1_right <-- hcomplex_mult_one_right
  2994   mult_zero_left <-- hcomplex_mult_zero_left
  2995   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2996   right_distrib <-- hypnat_add_mult_distrib2
  2997   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2998   right_inverse <-- hypreal_mult_inverse
  2999   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3000   order_refl <-- {hypreal,hypnat}_le_refl
  3001   order_trans <-- {hypreal,hypnat}_le_trans
  3002   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3003   order_less_le <-- {hypreal,hypnat}_less_le
  3004   linorder_linear <-- {hypreal,hypnat}_le_linear
  3005   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3006   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3007   add_nonneg_nonneg <-- hypreal_le_add_order
  3008 
  3009 * Hyperreal: Separate theorems having to do with type-specific
  3010 versions of constants have been merged into theorems that apply to the
  3011 new polymorphic constants (INCOMPATIBILITY):
  3012 
  3013   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3014   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3015   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3016   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3017   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3018   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3019   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3020   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3021   STAR_diff <-- {STAR,STARC}_diff
  3022   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3023     STARC_hcomplex_of_complex}_image_subset
  3024   starset_n_Un <-- starset{Nat,C}_n_Un
  3025   starset_n_Int <-- starset{Nat,C}_n_Int
  3026   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3027   starset_n_diff <-- starset{Nat,C}_n_diff
  3028   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3029   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3030   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3031   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3032   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3033   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3034   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3035   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3036   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3037   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3038   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3039   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3040   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3041   starfun_diff <-- starfun{C,RC,CR}_diff
  3042   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3043   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3044   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3045   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3046   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3047   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3048   starfun_Id <-- starfunC_Id
  3049   starfun_approx <-- starfun{Nat,CR}_approx
  3050   starfun_capprox <-- starfun{C,RC}_capprox
  3051   starfun_abs <-- starfunNat_rabs
  3052   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3053   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3054   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3055   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3056   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3057   starfun_add_approx <-- starfunCR_add_approx
  3058   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3059   starfun_divide <-- starfun{C,CR,RC}_divide
  3060   starfun_n <-- starfun{Nat,C}_n
  3061   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3062   starfun_n_add <-- starfun{Nat,C}_n_add
  3063   starfun_n_add_minus <-- starfunNat_n_add_minus
  3064   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3065   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3066   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3067 
  3068   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3069   star_n_minus <-- {hypreal,hcomplex}_minus
  3070   star_n_diff <-- {hypreal,hcomplex}_diff
  3071   star_n_mult <-- {hypreal,hcomplex}_mult
  3072   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3073   star_n_le <-- {hypreal,hypnat}_le
  3074   star_n_less <-- {hypreal,hypnat}_less
  3075   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3076   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3077   star_n_abs <-- hypreal_hrabs
  3078   star_n_divide <-- hcomplex_divide
  3079 
  3080   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3081   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3082   star_of_diff <-- hypreal_of_real_diff
  3083   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3084   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3085   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3086   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3087   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3088   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3089   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3090   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3091   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3092   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3093   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3094   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3095   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3096   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3097   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3098   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3099   star_of_power <-- hypreal_of_real_power
  3100   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3101 
  3102 * Hyperreal: new method "transfer" that implements the transfer
  3103 principle of nonstandard analysis. With a subgoal that mentions
  3104 nonstandard types like "'a star", the command "apply transfer"
  3105 replaces it with an equivalent one that mentions only standard types.
  3106 To be successful, all free variables must have standard types; non-
  3107 standard variables must have explicit universal quantifiers.
  3108 
  3109 * Hyperreal: A theory of Taylor series.
  3110 
  3111 
  3112 *** HOLCF ***
  3113 
  3114 * Discontinued special version of 'constdefs' (which used to support
  3115 continuous functions) in favor of the general Pure one with full
  3116 type-inference.
  3117 
  3118 * New simplification procedure for solving continuity conditions; it
  3119 is much faster on terms with many nested lambda abstractions (cubic
  3120 instead of exponential time).
  3121 
  3122 * New syntax for domain package: selector names are now optional.
  3123 Parentheses should be omitted unless argument is lazy, for example:
  3124 
  3125   domain 'a stream = cons "'a" (lazy "'a stream")
  3126 
  3127 * New command 'fixrec' for defining recursive functions with pattern
  3128 matching; defining multiple functions with mutual recursion is also
  3129 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3130 sinr, or any data constructor defined by the domain package. The given
  3131 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3132 syntax and examples.
  3133 
  3134 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3135 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3136 but the proof obligation additionally includes an admissibility
  3137 requirement. The packages generate instances of class cpo or pcpo,
  3138 with continuity and strictness theorems for Rep and Abs.
  3139 
  3140 * HOLCF: Many theorems have been renamed according to a more standard naming
  3141 scheme (INCOMPATIBILITY):
  3142 
  3143   foo_inject:  "foo$x = foo$y ==> x = y"
  3144   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3145   foo_less:    "(foo$x << foo$y) = (x << y)"
  3146   foo_strict:  "foo$UU = UU"
  3147   foo_defined: "... ==> foo$x ~= UU"
  3148   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3149 
  3150 
  3151 *** ZF ***
  3152 
  3153 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3154 including the First Isomorphism Theorem (on quotienting by the kernel
  3155 of a homomorphism).
  3156 
  3157 * ZF/Simplifier: install second copy of type solver that actually
  3158 makes use of TC rules declared to Isar proof contexts (or locales);
  3159 the old version is still required for ML proof scripts.
  3160 
  3161 
  3162 *** Cube ***
  3163 
  3164 * Converted to Isar theory format; use locales instead of axiomatic
  3165 theories.
  3166 
  3167 
  3168 *** ML ***
  3169 
  3170 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3171 for ||>, ||>>, |>>,
  3172 
  3173 * Pure/library.ML no longer defines its own option datatype, but uses
  3174 that of the SML basis, which has constructors NONE and SOME instead of
  3175 None and Some, as well as exception Option.Option instead of OPTION.
  3176 The functions the, if_none, is_some, is_none have been adapted
  3177 accordingly, while Option.map replaces apsome.
  3178 
  3179 * Pure/library.ML: the exception LIST has been given up in favour of
  3180 the standard exceptions Empty and Subscript, as well as
  3181 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3182 superceded by the standard hd and tl functions etc.
  3183 
  3184 A number of basic list functions are no longer exported to the ML
  3185 toplevel, as they are variants of predefined functions.  The following
  3186 suggests how one can translate existing code:
  3187 
  3188     rev_append xs ys = List.revAppend (xs, ys)
  3189     nth_elem (i, xs) = List.nth (xs, i)
  3190     last_elem xs = List.last xs
  3191     flat xss = List.concat xss
  3192     seq fs = List.app fs
  3193     partition P xs = List.partition P xs
  3194     mapfilter f xs = List.mapPartial f xs
  3195 
  3196 * Pure/library.ML: several combinators for linear functional
  3197 transformations, notably reverse application and composition:
  3198 
  3199   x |> f                f #> g
  3200   (x, y) |-> f          f #-> g
  3201 
  3202 * Pure/library.ML: introduced/changed precedence of infix operators:
  3203 
  3204   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3205   infix 2 ?;
  3206   infix 3 o oo ooo oooo;
  3207   infix 4 ~~ upto downto;
  3208 
  3209 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3210 infix operators.
  3211 
  3212 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3213 fold_map support linear functional transformations and nesting.  For
  3214 example:
  3215 
  3216   fold f [x1, ..., xN] y =
  3217     y |> f x1 |> ... |> f xN
  3218 
  3219   (fold o fold) f [xs1, ..., xsN] y =
  3220     y |> fold f xs1 |> ... |> fold f xsN
  3221 
  3222   fold f [x1, ..., xN] =
  3223     f x1 #> ... #> f xN
  3224 
  3225   (fold o fold) f [xs1, ..., xsN] =
  3226     fold f xs1 #> ... #> fold f xsN
  3227 
  3228 * Pure/library.ML: the following selectors on type 'a option are
  3229 available:
  3230 
  3231   the:               'a option -> 'a  (*partial*)
  3232   these:             'a option -> 'a  where 'a = 'b list
  3233   the_default: 'a -> 'a option -> 'a
  3234   the_list:          'a option -> 'a list
  3235 
  3236 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3237 basic operations for association lists, following natural argument
  3238 order; moreover the explicit equality predicate passed here avoids
  3239 potentially expensive polymorphic runtime equality checks.
  3240 The old functions may be expressed as follows:
  3241 
  3242   assoc = uncurry (AList.lookup (op =))
  3243   assocs = these oo AList.lookup (op =)
  3244   overwrite = uncurry (AList.update (op =)) o swap
  3245 
  3246 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3247 
  3248   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3249   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3250 
  3251 replacing make_keylist and keyfilter (occassionally used)
  3252 Naive rewrites:
  3253 
  3254   make_keylist = AList.make
  3255   keyfilter = AList.find (op =)
  3256 
  3257 * eq_fst and eq_snd now take explicit equality parameter, thus
  3258   avoiding eqtypes. Naive rewrites:
  3259 
  3260     eq_fst = eq_fst (op =)
  3261     eq_snd = eq_snd (op =)
  3262 
  3263 * Removed deprecated apl and apr (rarely used).
  3264   Naive rewrites:
  3265 
  3266     apl (n, op) =>>= curry op n
  3267     apr (op, m) =>>= fn n => op (n, m)
  3268 
  3269 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3270 provides a reasonably efficient light-weight implementation of sets as
  3271 lists.
  3272 
  3273 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3274 few new operations; existing lookup and update are now curried to
  3275 follow natural argument order (for use with fold etc.);
  3276 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3277 
  3278 * Pure/General: output via the Isabelle channels of
  3279 writeln/warning/error etc. is now passed through Output.output, with a
  3280 hook for arbitrary transformations depending on the print_mode
  3281 (cf. Output.add_mode -- the first active mode that provides a output
  3282 function wins).  Already formatted output may be embedded into further
  3283 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3284 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3285 accommodate easy composition of diagnostic messages etc.  Programmers
  3286 rarely need to care about Output.output or Output.raw at all, with
  3287 some notable exceptions: Output.output is required when bypassing the
  3288 standard channels (writeln etc.), or in token translations to produce
  3289 properly formatted results; Output.raw is required when capturing
  3290 already output material that will eventually be presented to the user
  3291 a second time.  For the default print mode, both Output.output and
  3292 Output.raw have no effect.
  3293 
  3294 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3295 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3296 cumulative results are displayed at the end of a batch session.
  3297 
  3298 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3299 replaced by File.platform_path and File.shell_path (with appropriate
  3300 hooks).  This provides a clean interface for unusual systems where the
  3301 internal and external process view of file names are different.
  3302 
  3303 * Pure: more efficient orders for basic syntactic entities: added
  3304 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3305 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3306 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3307 orders now -- potential INCOMPATIBILITY for code that depends on a
  3308 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3309 Library.sort_strings on result).
  3310 
  3311 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3312 fold_types traverse types/terms from left to right, observing natural
  3313 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3314 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3315 
  3316 * Pure: name spaces have been refined, with significant changes of the
  3317 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3318 to extern(_table).  The plain name entry path is superceded by a
  3319 general 'naming' context, which also includes the 'policy' to produce
  3320 a fully qualified name and external accesses of a fully qualified
  3321 name; NameSpace.extend is superceded by context dependent
  3322 Sign.declare_name.  Several theory and proof context operations modify
  3323 the naming context.  Especially note Theory.restore_naming and
  3324 ProofContext.restore_naming to get back to a sane state; note that
  3325 Theory.add_path is no longer sufficient to recover from
  3326 Theory.absolute_path in particular.
  3327 
  3328 * Pure: new flags short_names (default false) and unique_names
  3329 (default true) for controlling output of qualified names.  If
  3330 short_names is set, names are printed unqualified.  If unique_names is
  3331 reset, the name prefix is reduced to the minimum required to achieve
  3332 the original result when interning again, even if there is an overlap
  3333 with earlier declarations.
  3334 
  3335 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3336 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3337 (useful for printing error messages).  INCOMPATIBILITY.
  3338 
  3339 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3340 Theory.theory are now identified, referring to the universal
  3341 Context.theory (see Pure/context.ML).  Actual signature and theory
  3342 content is managed as theory data.  The old code and interfaces were
  3343 spread over many files and structures; the new arrangement introduces
  3344 considerable INCOMPATIBILITY to gain more clarity:
  3345 
  3346   Context -- theory management operations (name, identity, inclusion,
  3347     parents, ancestors, merge, etc.), plus generic theory data;
  3348 
  3349   Sign -- logical signature and syntax operations (declaring consts,
  3350     types, etc.), plus certify/read for common entities;
  3351 
  3352   Theory -- logical theory operations (stating axioms, definitions,
  3353     oracles), plus a copy of logical signature operations (consts,
  3354     types, etc.); also a few basic management operations (Theory.copy,
  3355     Theory.merge, etc.)
  3356 
  3357 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3358 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3359 for convenience -- they merely return the theory.
  3360 
  3361 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3362 
  3363 * Pure: the Isar proof context type is already defined early in Pure
  3364 as Context.proof (note that ProofContext.context and Proof.context are
  3365 aliases, where the latter is the preferred name).  This enables other
  3366 Isabelle components to refer to that type even before Isar is present.
  3367 
  3368 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3369 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3370 any of these kinds.  For example, Sign.intern typeK is now
  3371 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3372 Theory.hide_types.  Also note that former
  3373 Theory.hide_classes/types/consts are now
  3374 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3375 internalize their arguments!  INCOMPATIBILITY.
  3376 
  3377 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3378 datatype thmref (with constructors Name and NameSelection) instead of
  3379 plain string -- INCOMPATIBILITY;
  3380 
  3381 * Pure: cases produced by proof methods specify options, where NONE
  3382 means to remove case bindings -- INCOMPATIBILITY in
  3383 (RAW_)METHOD_CASES.
  3384 
  3385 * Pure: the following operations retrieve axioms or theorems from a
  3386 theory node or theory hierarchy, respectively:
  3387 
  3388   Theory.axioms_of: theory -> (string * term) list
  3389   Theory.all_axioms_of: theory -> (string * term) list
  3390   PureThy.thms_of: theory -> (string * thm) list
  3391   PureThy.all_thms_of: theory -> (string * thm) list
  3392 
  3393 * Pure: print_tac now outputs the goal through the trace channel.
  3394 
  3395 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3396 Reference Toplevel.debug (default false) controls detailed printing
  3397 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3398 controls execution profiling -- set to 1 for time and 2 for space
  3399 (both increase the runtime).
  3400 
  3401 * Isar session: The initial use of ROOT.ML is now always timed,
  3402 i.e. the log will show the actual process times, in contrast to the
  3403 elapsed wall-clock time that the outer shell wrapper produces.
  3404 
  3405 * Simplifier: improved handling of bound variables (nameless
  3406 representation, avoid allocating new strings).  Simprocs that invoke
  3407 the Simplifier recursively should use Simplifier.inherit_bounds to
  3408 avoid local name clashes.  Failure to do so produces warnings
  3409 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3410 for further details.
  3411 
  3412 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3413 bindings for all theorems stored within a given theory; this may help
  3414 in porting non-Isar theories to Isar ones, while keeping ML proof
  3415 scripts for the time being.
  3416 
  3417 * ML operator HTML.with_charset specifies the charset begin used for
  3418 generated HTML files.  For example:
  3419 
  3420   HTML.with_charset "utf-8" use_thy "Hebrew";
  3421   HTML.with_charset "utf-8" use_thy "Chinese";
  3422 
  3423 
  3424 *** System ***
  3425 
  3426 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3427 isabelle, isatool etc.).
  3428 
  3429 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3430 isatool doc, isatool mkdir, display_drafts etc.).
  3431 
  3432 * isatool usedir: option -f allows specification of the ML file to be
  3433 used by Isabelle; default is ROOT.ML.
  3434 
  3435 * New isatool version outputs the version identifier of the Isabelle
  3436 distribution being used.
  3437 
  3438 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3439 (containing Boolean satisfiability problems) into Isabelle/HOL
  3440 theories.
  3441 
  3442 
  3443 
  3444 New in Isabelle2004 (April 2004)
  3445 --------------------------------
  3446 
  3447 *** General ***
  3448 
  3449 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3450   Replaces linorder.ML.
  3451 
  3452 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3453   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3454   (\<a>...\<z>), are now considered normal letters, and can therefore
  3455   be used anywhere where an ASCII letter (a...zA...Z) has until
  3456   now. COMPATIBILITY: This obviously changes the parsing of some
  3457   terms, especially where a symbol has been used as a binder, say
  3458   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3459   as an identifier.  Fix it by inserting a space around former
  3460   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3461   existing theory and ML files.
  3462 
  3463 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3464 
  3465 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3466   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3467   a normal (but invisible) letter. For multiple letter subscripts repeat
  3468   \<^isub> like this: x\<^isub>1\<^isub>2.
  3469 
  3470 * Pure: There are now sub-/superscripts that can span more than one
  3471   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3472   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3473   superscript. The new control characters are not identifier parts.
  3474 
  3475 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3476   content of "..." to the latex file instead of \isacntrl... . The "..."
  3477   may consist of any printable characters excluding the end bracket >.
  3478 
  3479 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3480   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3481   declare constants "final", which prevents their being given a definition
  3482   later.  It is useful for constants whose behaviour is fixed axiomatically
  3483   rather than definitionally, such as the meta-logic connectives.
  3484 
  3485 * Pure: 'instance' now handles general arities with general sorts
  3486   (i.e. intersections of classes),
  3487 
  3488 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3489   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3490   It can be changed to alter the colors/layout of generated pages.
  3491 
  3492 
  3493 *** Isar ***
  3494 
  3495 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3496   cut_tac, subgoal_tac and thin_tac:
  3497   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3498     locales are no longer forced to write Isar proof scripts.
  3499     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3500     emulations.
  3501   - INCOMPATIBILITY: names of variables to be instantiated may no
  3502     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3503     This is consistent with the instantiation attribute "where".
  3504 
  3505 * Attributes "where" and "of":
  3506   - Now take type variables of instantiated theorem into account when reading
  3507     the instantiation string.  This fixes a bug that caused instantiated
  3508     theorems to have too special types in some circumstances.
  3509   - "where" permits explicit instantiations of type variables.
  3510 
  3511 * Calculation commands "moreover" and "also" no longer interfere with
  3512   current facts ("this"), admitting arbitrary combinations with "then"
  3513   and derived forms.
  3514 
  3515 * Locales:
  3516   - Goal statements involving the context element "includes" no longer
  3517     generate theorems with internal delta predicates (those ending on
  3518     "_axioms") in the premise.
  3519     Resolve particular premise with <locale>.intro to obtain old form.
  3520   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3521     specification and "includes" elements in goal statement.
  3522   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3523     [intro?] and [elim?] (respectively) by default.
  3524   - Experimental command for instantiation of locales in proof contexts:
  3525         instantiate <label>[<attrs>]: <loc>
  3526     Instantiates locale <loc> and adds all its theorems to the current context
  3527     taking into account their attributes.  Label and attrs are optional
  3528     modifiers, like in theorem declarations.  If present, names of
  3529     instantiated theorems are qualified with <label>, and the attributes
  3530     <attrs> are applied after any attributes these theorems might have already.
  3531       If the locale has assumptions, a chained fact of the form
  3532     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3533     are derived.  The command does not support old-style locales declared
  3534     with "locale (open)".
  3535       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3536 
  3537 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3538   (Isar) contexts.
  3539 
  3540 
  3541 *** HOL ***
  3542 
  3543 * Proof import: new image HOL4 contains the imported library from
  3544   the HOL4 system with about 2500 theorems. It is imported by
  3545   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3546   can be used like any other Isabelle image.  See
  3547   HOL/Import/HOL/README for more information.
  3548 
  3549 * Simplifier:
  3550   - Much improved handling of linear and partial orders.
  3551     Reasoners for linear and partial orders are set up for type classes
  3552     "linorder" and "order" respectively, and are added to the default simpset
  3553     as solvers.  This means that the simplifier can build transitivity chains
  3554     to solve goals from the assumptions.
  3555   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3556     of blast or auto after simplification become unnecessary because the goal
  3557     is solved by simplification already.
  3558 
  3559 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3560     all proved in axiomatic type classes for semirings, rings and fields.
  3561 
  3562 * Numerics:
  3563   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3564     now formalized using the Ring_and_Field theory mentioned above.
  3565   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3566     than before, because now they are set up once in a generic manner.
  3567   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3568     Look for the general versions in Ring_and_Field (and Power if they concern
  3569     exponentiation).
  3570 
  3571 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3572 
  3573 * Records:
  3574   - Record types are now by default printed with their type abbreviation
  3575     instead of the list of all field types. This can be configured via
  3576     the reference "print_record_type_abbr".
  3577   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3578     (not enabled by default).
  3579   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3580     EX x. x = sel r to True (not enabled by default).
  3581   - Tactic "record_split_simp_tac" to split and simplify records added.
  3582 
  3583 * 'specification' command added, allowing for definition by
  3584   specification.  There is also an 'ax_specification' command that
  3585   introduces the new constants axiomatically.
  3586 
  3587 * arith(_tac) is now able to generate counterexamples for reals as well.
  3588 
  3589 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3590 
  3591 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3592   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3593 
  3594 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3595   matrix theory to linear programming.
  3596 
  3597 * Unions and Intersections:
  3598   The latex output syntax of UN and INT has been changed
  3599   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3600   i.e. the index formulae has become a subscript.
  3601   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3602 
  3603 * Unions and Intersections over Intervals:
  3604   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3605   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3606   like in normal math, and corresponding versions for < and for intersection.
  3607 
  3608 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3609   lexicographic dictonary ordering has been added as "lexord".
  3610 
  3611 * ML: the legacy theory structures Int and List have been removed. They had
  3612   conflicted with ML Basis Library structures having the same names.
  3613 
  3614 * 'refute' command added to search for (finite) countermodels.  Only works
  3615   for a fragment of HOL.  The installation of an external SAT solver is
  3616   highly recommended.  See "HOL/Refute.thy" for details.
  3617 
  3618 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3619   formulae under an assignment of free variables to random values.
  3620   In contrast to 'refute', it can deal with inductive datatypes,
  3621   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3622   for examples.
  3623 
  3624 
  3625 *** HOLCF ***
  3626 
  3627 * Streams now come with concatenation and are part of the HOLCF image
  3628 
  3629 
  3630 
  3631 New in Isabelle2003 (May 2003)
  3632 ------------------------------
  3633 
  3634 *** General ***
  3635 
  3636 * Provers/simplifier:
  3637 
  3638   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3639     Assumptions are now subject to complete mutual simplification,
  3640     not just from left to right. The simplifier now preserves
  3641     the order of assumptions.
  3642 
  3643     Potential INCOMPATIBILITY:
  3644 
  3645     -- simp sometimes diverges where the old version did
  3646        not, e.g. invoking simp on the goal
  3647 
  3648         [| P (f x); y = x; f x = f y |] ==> Q
  3649 
  3650        now gives rise to the infinite reduction sequence
  3651 
  3652         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3653 
  3654        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3655        kind of problem.
  3656 
  3657     -- Tactics combining classical reasoner and simplification (such as auto)
  3658        are also affected by this change, because many of them rely on
  3659        simp. They may sometimes diverge as well or yield a different numbers
  3660        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3661        in case of problems. Sometimes subsequent calls to the classical
  3662        reasoner will fail because a preceeding call to the simplifier too
  3663        eagerly simplified the goal, e.g. deleted redundant premises.
  3664 
  3665   - The simplifier trace now shows the names of the applied rewrite rules
  3666 
  3667   - You can limit the number of recursive invocations of the simplifier
  3668     during conditional rewriting (where the simplifie tries to solve the
  3669     conditions before applying the rewrite rule):
  3670     ML "simp_depth_limit := n"
  3671     where n is an integer. Thus you can force termination where previously
  3672     the simplifier would diverge.
  3673 
  3674   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3675 
  3676   - No longer aborts on failed congruence proof.  Instead, the
  3677     congruence is ignored.
  3678 
  3679 * Pure: New generic framework for extracting programs from constructive
  3680   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3681   as HOL/Extraction for some case studies.
  3682 
  3683 * Pure: The main goal of the proof state is no longer shown by default, only
  3684 the subgoals. This behaviour is controlled by a new flag.
  3685    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3686 (ML: Proof.show_main_goal).
  3687 
  3688 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3689 rules whose conclusion matches subgoal 1:
  3690       PG menu: Isabelle/Isar -> Show me -> matching rules
  3691 The rules are ordered by how closely they match the subgoal.
  3692 In particular, rules that solve a subgoal outright are displayed first
  3693 (or rather last, the way they are printed).
  3694 (ML: ProofGeneral.print_intros())
  3695 
  3696 * Pure: New flag trace_unify_fail causes unification to print
  3697 diagnostic information (PG: in trace buffer) when it fails. This is
  3698 useful for figuring out why single step proofs like rule, erule or
  3699 assumption failed.
  3700 
  3701 * Pure: Locale specifications now produce predicate definitions
  3702 according to the body of text (covering assumptions modulo local
  3703 definitions); predicate "loc_axioms" covers newly introduced text,
  3704 while "loc" is cumulative wrt. all included locale expressions; the
  3705 latter view is presented only on export into the global theory
  3706 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3707 on the old view without predicates;
  3708 
  3709 * Pure: predefined locales "var" and "struct" are useful for sharing
  3710 parameters (as in CASL, for example); just specify something like
  3711 ``var x + var y + struct M'' as import;
  3712 
  3713 * Pure: improved thms_containing: proper indexing of facts instead of
  3714 raw theorems; check validity of results wrt. current name space;
  3715 include local facts of proof configuration (also covers active
  3716 locales), cover fixed variables in index; may use "_" in term
  3717 specification; an optional limit for the number of printed facts may
  3718 be given (the default is 40);
  3719 
  3720 * Pure: disallow duplicate fact bindings within new-style theory files
  3721 (batch-mode only);
  3722 
  3723 * Provers: improved induct method: assumptions introduced by case
  3724 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3725 the goal statement); "foo" still refers to all facts collectively;
  3726 
  3727 * Provers: the function blast.overloaded has been removed: all constants
  3728 are regarded as potentially overloaded, which improves robustness in exchange
  3729 for slight decrease in efficiency;
  3730 
  3731 * Provers/linorder: New generic prover for transitivity reasoning over
  3732 linear orders.  Note: this prover is not efficient!
  3733 
  3734 * Isar: preview of problems to finish 'show' now produce an error
  3735 rather than just a warning (in interactive mode);
  3736 
  3737 
  3738 *** HOL ***
  3739 
  3740 * arith(_tac)
  3741 
  3742  - Produces a counter example if it cannot prove a goal.
  3743    Note that the counter example may be spurious if the goal is not a formula
  3744    of quantifier-free linear arithmetic.
  3745    In ProofGeneral the counter example appears in the trace buffer.
  3746 
  3747  - Knows about div k and mod k where k is a numeral of type nat or int.
  3748 
  3749  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3750    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3751    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3752 
  3753 * simp's arithmetic capabilities have been enhanced a bit: it now
  3754 takes ~= in premises into account (by performing a case split);
  3755 
  3756 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3757 are distributed over a sum of terms;
  3758 
  3759 * New tactic "trans_tac" and method "trans" instantiate
  3760 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3761 "<=", "<" and "=").
  3762 
  3763 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3764 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3765 
  3766 * 'typedef' command has new option "open" to suppress the set
  3767 definition;
  3768 
  3769 * functions Min and Max on finite sets have been introduced (theory
  3770 Finite_Set);
  3771 
  3772 * attribute [symmetric] now works for relations as well; it turns
  3773 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3774 
  3775 * induct over a !!-quantified statement (say !!x1..xn):
  3776   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3777 
  3778 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3779 %x. None. Warning: empty_def now refers to the previously hidden definition
  3780 of the empty set.
  3781 
  3782 * Algebra: formalization of classical algebra.  Intended as base for
  3783 any algebraic development in Isabelle.  Currently covers group theory
  3784 (up to Sylow's theorem) and ring theory (Universal Property of
  3785 Univariate Polynomials).  Contributions welcome;
  3786 
  3787 * GroupTheory: deleted, since its material has been moved to Algebra;
  3788 
  3789 * Complex: new directory of the complex numbers with numeric constants,
  3790 nonstandard complex numbers, and some complex analysis, standard and
  3791 nonstandard (Jacques Fleuriot);
  3792 
  3793 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3794 
  3795 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3796 Fleuriot);
  3797 
  3798 * Real/HahnBanach: updated and adapted to locales;
  3799 
  3800 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3801 Gray and Kramer);
  3802 
  3803 * UNITY: added the Meier-Sanders theory of progress sets;
  3804 
  3805 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3806 as abstract algorithms, instantiated to the JVM;
  3807 
  3808 * Bali: Java source language formalization. Type system, operational
  3809 semantics, axiomatic semantics. Supported language features:
  3810 classes, interfaces, objects,virtual methods, static methods,
  3811 static/instance fields, arrays, access modifiers, definite
  3812 assignment, exceptions.
  3813 
  3814 
  3815 *** ZF ***
  3816 
  3817 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3818 universe, etc.);
  3819 
  3820 * Main ZF: virtually all theories converted to new-style format;
  3821 
  3822 
  3823 *** ML ***
  3824 
  3825 * Pure: Tactic.prove provides sane interface for internal proofs;
  3826 omits the infamous "standard" operation, so this is more appropriate
  3827 than prove_goalw_cterm in many situations (e.g. in simprocs);
  3828 
  3829 * Pure: improved error reporting of simprocs;
  3830 
  3831 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  3832 up simprocs;
  3833 
  3834 
  3835 *** Document preparation ***
  3836 
  3837 * uses \par instead of \\ for line breaks in theory text. This may
  3838 shift some page breaks in large documents. To get the old behaviour
  3839 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  3840 
  3841 * minimized dependencies of isabelle.sty and isabellesym.sty on
  3842 other packages
  3843 
  3844 * \<euro> now needs package babel/greek instead of marvosym (which
  3845 broke \Rightarrow)
  3846 
  3847 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  3848 textcomp package)
  3849 
  3850 
  3851 
  3852 New in Isabelle2002 (March 2002)
  3853 --------------------------------
  3854 
  3855 *** Document preparation ***
  3856 
  3857 * greatly simplified document preparation setup, including more
  3858 graceful interpretation of isatool usedir -i/-d/-D options, and more
  3859 instructive isatool mkdir; users should basically be able to get
  3860 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  3861 users may run a separate document processing stage manually like this:
  3862 "isatool usedir -D output HOL Test && isatool document Test/output";
  3863 
  3864 * theory dependency graph may now be incorporated into documents;
  3865 isatool usedir -g true will produce session_graph.eps/.pdf for use
  3866 with \includegraphics of LaTeX;
  3867 
  3868 * proper spacing of consecutive markup elements, especially text
  3869 blocks after section headings;
  3870 
  3871 * support bold style (for single symbols only), input syntax is like
  3872 this: "\<^bold>\<alpha>" or "\<^bold>A";
  3873 
  3874 * \<bullet> is now output as bold \cdot by default, which looks much
  3875 better in printed text;
  3876 
  3877 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  3878 note that these symbols are currently unavailable in Proof General /
  3879 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  3880 
  3881 * isatool latex no longer depends on changed TEXINPUTS, instead
  3882 isatool document copies the Isabelle style files to the target
  3883 location;
  3884 
  3885 
  3886 *** Isar ***
  3887 
  3888 * Pure/Provers: improved proof by cases and induction;
  3889   - 'case' command admits impromptu naming of parameters (such as
  3890     "case (Suc n)");
  3891   - 'induct' method divinates rule instantiation from the inductive
  3892     claim; no longer requires excessive ?P bindings for proper
  3893     instantiation of cases;
  3894   - 'induct' method properly enumerates all possibilities of set/type
  3895     rules; as a consequence facts may be also passed through *type*
  3896     rules without further ado;
  3897   - 'induct' method now derives symbolic cases from the *rulified*
  3898     rule (before it used to rulify cases stemming from the internal
  3899     atomized version); this means that the context of a non-atomic
  3900     statement becomes is included in the hypothesis, avoiding the
  3901     slightly cumbersome show "PROP ?case" form;
  3902   - 'induct' may now use elim-style induction rules without chaining
  3903     facts, using ``missing'' premises from the goal state; this allows
  3904     rules stemming from inductive sets to be applied in unstructured
  3905     scripts, while still benefitting from proper handling of non-atomic
  3906     statements; NB: major inductive premises need to be put first, all
  3907     the rest of the goal is passed through the induction;
  3908   - 'induct' proper support for mutual induction involving non-atomic
  3909     rule statements (uses the new concept of simultaneous goals, see
  3910     below);
  3911   - append all possible rule selections, but only use the first
  3912     success (no backtracking);
  3913   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  3914   - undeclared rule case names default to numbers 1, 2, 3, ...;
  3915   - added 'print_induct_rules' (covered by help item in recent Proof
  3916     General versions);
  3917   - moved induct/cases attributes to Pure, methods to Provers;
  3918   - generic method setup instantiated for FOL and HOL;
  3919 
  3920 * Pure: support multiple simultaneous goal statements, for example
  3921 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  3922 meta-level mechanism, this acts as if several individual goals had
  3923 been stated separately; in particular common proof methods need to be
  3924 repeated in order to cover all claims; note that a single elimination
  3925 step is *not* sufficient to establish the two conjunctions, so this
  3926 fails:
  3927 
  3928   assume "A & B" then have A and B ..   (*".." fails*)
  3929 
  3930 better use "obtain" in situations as above; alternative refer to
  3931 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  3932 
  3933 * Pure: proper integration with ``locales''; unlike the original
  3934 version by Florian Kammller, Isar locales package high-level proof
  3935 contexts rather than raw logical ones (e.g. we admit to include
  3936 attributes everywhere); operations on locales include merge and
  3937 rename; support for implicit arguments (``structures''); simultaneous
  3938 type-inference over imports and text; see also HOL/ex/Locales.thy for
  3939 some examples;
  3940 
  3941 * Pure: the following commands have been ``localized'', supporting a
  3942 target locale specification "(in name)": 'lemma', 'theorem',
  3943 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  3944 stored both within the locale and at the theory level (exported and
  3945 qualified by the locale name);
  3946 
  3947 * Pure: theory goals may now be specified in ``long'' form, with
  3948 ad-hoc contexts consisting of arbitrary locale elements. for example
  3949 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  3950 definitions may be given, too); the result is a meta-level rule with
  3951 the context elements being discharged in the obvious way;
  3952 
  3953 * Pure: new proof command 'using' allows to augment currently used
  3954 facts after a goal statement ('using' is syntactically analogous to
  3955 'apply', but acts on the goal's facts only); this allows chained facts
  3956 to be separated into parts given before and after a claim, as in
  3957 ``from a and b have C using d and e <proof>'';
  3958 
  3959 * Pure: renamed "antecedent" case to "rule_context";
  3960 
  3961 * Pure: new 'judgment' command records explicit information about the
  3962 object-logic embedding (used by several tools internally); no longer
  3963 use hard-wired "Trueprop";
  3964 
  3965 * Pure: added 'corollary' command;
  3966 
  3967 * Pure: fixed 'token_translation' command;
  3968 
  3969 * Pure: removed obsolete 'exported' attribute;
  3970 
  3971 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3972 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3973 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3974 
  3975 * Pure: method 'atomize' presents local goal premises as object-level
  3976 statements (atomic meta-level propositions); setup controlled via
  3977 rewrite rules declarations of 'atomize' attribute; example
  3978 application: 'induct' method with proper rule statements in improper
  3979 proof *scripts*;
  3980 
  3981 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3982 now consider the syntactic context of assumptions, giving a better
  3983 chance to get type-inference of the arguments right (this is
  3984 especially important for locales);
  3985 
  3986 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3987 mode;
  3988 
  3989 * Pure/obtain: the formal conclusion "thesis", being marked as
  3990 ``internal'', may no longer be reference directly in the text;
  3991 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3992 situations;
  3993 
  3994 * Pure: generic 'sym' attribute which declares a rule both as pure
  3995 'elim?' and for the 'symmetric' operation;
  3996 
  3997 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3998 text; the fixed correlation with particular command syntax has been
  3999 discontinued;
  4000 
  4001 * Pure: new method 'rules' is particularly well-suited for proof
  4002 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4003 but often produces more compact proof terms with less detours;
  4004 
  4005 * Pure/Provers/classical: simplified integration with pure rule
  4006 attributes and methods; the classical "intro?/elim?/dest?"
  4007 declarations coincide with the pure ones; the "rule" method no longer
  4008 includes classically swapped intros; "intro" and "elim" methods no
  4009 longer pick rules from the context; also got rid of ML declarations
  4010 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4011 INCOMPATIBILITY;
  4012 
  4013 * Provers/classical: attribute 'swapped' produces classical inversions
  4014 of introduction rules;
  4015 
  4016 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4017 rules instead of full simplifier context; 'iff' attribute handles
  4018 conditional rules;
  4019 
  4020 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4021 
  4022 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4023 "(permissive)" option to recover old behavior;
  4024 
  4025 * HOL: 'inductive' no longer features separate (collective) attributes
  4026 for 'intros' (was found too confusing);
  4027 
  4028 * HOL: properly declared induction rules less_induct and
  4029 wf_induct_rule;
  4030 
  4031 
  4032 *** HOL ***
  4033 
  4034 * HOL: moved over to sane numeral syntax; the new policy is as
  4035 follows:
  4036 
  4037   - 0 and 1 are polymorphic constants, which are defined on any
  4038   numeric type (nat, int, real etc.);
  4039 
  4040   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4041   binary representation internally;
  4042 
  4043   - type nat has special constructor Suc, and generally prefers Suc 0
  4044   over 1::nat and Suc (Suc 0) over 2::nat;
  4045 
  4046 This change may cause significant problems of INCOMPATIBILITY; here
  4047 are some hints on converting existing sources:
  4048 
  4049   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4050   entities, so expressions involving "-" (unary or binary minus) need
  4051   to be spaced properly;
  4052 
  4053   - existing occurrences of "1" may need to be constraint "1::nat" or
  4054   even replaced by Suc 0; similar for old "2";
  4055 
  4056   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4057 
  4058   - remove all special provisions on numerals in proofs;
  4059 
  4060 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4061 representation (depends on bin_arith_simps in the default context);
  4062 
  4063 * HOL: symbolic syntax for x^2 (numeral 2);
  4064 
  4065 * HOL: the class of all HOL types is now called "type" rather than
  4066 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4067 in axclass/classes, instance/arities, and (usually rare) occurrences
  4068 in typings (of consts etc.); internally the class is called
  4069 "HOL.type", ML programs should refer to HOLogic.typeS;
  4070 
  4071 * HOL/record package improvements:
  4072   - new derived operations "fields" to build a partial record section,
  4073     "extend" to promote a fixed record to a record scheme, and
  4074     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4075     declared as simp by default;
  4076   - shared operations ("more", "fields", etc.) now need to be always
  4077     qualified) --- potential INCOMPATIBILITY;
  4078   - removed "make_scheme" operations (use "make" with "extend") --
  4079     INCOMPATIBILITY;
  4080   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4081   - provides cases/induct rules for use with corresponding Isar
  4082     methods (for concrete records, record schemes, concrete more
  4083     parts, and schematic more parts -- in that order);
  4084   - internal definitions directly based on a light-weight abstract
  4085     theory of product types over typedef rather than datatype;
  4086 
  4087 * HOL: generic code generator for generating executable ML code from
  4088 specifications; specific support for HOL constructs such as inductive
  4089 datatypes and sets, as well as recursive functions; can be invoked
  4090 via 'generate_code' theory section;
  4091 
  4092 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4093 
  4094 * HOL: consolidated and renamed several theories.  In particular:
  4095         Ord.thy has been absorbed into HOL.thy
  4096         String.thy has been absorbed into List.thy
  4097 
  4098 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4099 (beware of argument permutation!);
  4100 
  4101 * HOL: linorder_less_split superseded by linorder_cases;
  4102 
  4103 * HOL/List: "nodups" renamed to "distinct";
  4104 
  4105 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4106 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4107   - Ex_def has changed, now need to use some_eq_ex
  4108 
  4109 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4110 in this (rare) case use:
  4111 
  4112   delSWrapper "split_all_tac"
  4113   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4114 
  4115 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4116 MAY FAIL;
  4117 
  4118 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4119 Isabelle's type classes, ^ on functions and relations has too general
  4120 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4121 necessary to attach explicit type constraints;
  4122 
  4123 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4124 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4125 renamed accordingly (eg "compI" -> "rel_compI").
  4126 
  4127 * HOL: syntax translations now work properly with numerals and records
  4128 expressions;
  4129 
  4130 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4131 of "lam" -- INCOMPATIBILITY;
  4132 
  4133 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4134 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4135 renamed "Product_Type.unit";
  4136 
  4137 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4138 
  4139 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4140 the "cases" method);
  4141 
  4142 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4143 Florian Kammller);
  4144 
  4145 * HOL/IMP: updated and converted to new-style theory format; several
  4146 parts turned into readable document, with proper Isar proof texts and
  4147 some explanations (by Gerwin Klein);
  4148 
  4149 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4150 
  4151 * HOL-Hyperreal is now a logic image;
  4152 
  4153 
  4154 *** HOLCF ***
  4155 
  4156 * Isar: consts/constdefs supports mixfix syntax for continuous
  4157 operations;
  4158 
  4159 * Isar: domain package adapted to new-style theory format, e.g. see
  4160 HOLCF/ex/Dnat.thy;
  4161 
  4162 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4163 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4164 lift.induct_tac, always use UU instead of Undef;
  4165 
  4166 * HOLCF/IMP: updated and converted to new-style theory;
  4167 
  4168 
  4169 *** ZF ***
  4170 
  4171 * Isar: proper integration of logic-specific tools and packages,
  4172 including theory commands '(co)inductive', '(co)datatype',
  4173 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4174 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4175 
  4176 * theory Main no longer includes AC; for the Axiom of Choice, base
  4177 your theory on Main_ZFC;
  4178 
  4179 * the integer library now covers quotients and remainders, with many
  4180 laws relating division to addition, multiplication, etc.;
  4181 
  4182 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4183 typeless version of the formalism;
  4184 
  4185 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4186 format;
  4187 
  4188 * ZF/Induct: new directory for examples of inductive definitions,
  4189 including theory Multiset for multiset orderings; converted to
  4190 new-style theory format;
  4191 
  4192 * ZF: many new theorems about lists, ordinals, etc.;
  4193 
  4194 
  4195 *** General ***
  4196 
  4197 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4198 variable proof controls level of detail: 0 = no proofs (only oracle
  4199 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4200 also ref manual for further ML interfaces;
  4201 
  4202 * Pure/axclass: removed obsolete ML interface
  4203 goal_subclass/goal_arity;
  4204 
  4205 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4206 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4207 separate tokens, so expressions involving minus need to be spaced
  4208 properly;
  4209 
  4210 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4211 rather than "infixl" or "infixr";
  4212 
  4213 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4214 sort constraint specifications in type inference; e.g. "x::_::foo"
  4215 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4216 type variable);
  4217 
  4218 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4219 control output of nested => (types); the default behavior is
  4220 "type_brackets";
  4221 
  4222 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4223 tokens into AST constants;
  4224 
  4225 * Pure/syntax: prefer later declarations of translations and print
  4226 translation functions; potential INCOMPATIBILITY: need to reverse
  4227 multiple declarations for same syntax element constant;
  4228 
  4229 * Pure/show_hyps reset by default (in accordance to existing Isar
  4230 practice);
  4231 
  4232 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4233 addSafter;
  4234 
  4235 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4236 as well;
  4237 
  4238 * system: tested support for MacOS X; should be able to get Isabelle +
  4239 Proof General to work in a plain Terminal after installing Poly/ML
  4240 (e.g. from the Isabelle distribution area) and GNU bash alone
  4241 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4242 support requires further installations, e.g. from
  4243 http://fink.sourceforge.net/);
  4244 
  4245 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4246 
  4247 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4248 of 40 MB), cf. ML_OPTIONS;
  4249 
  4250 * system: Proof General keywords specification is now part of the
  4251 Isabelle distribution (see etc/isar-keywords.el);
  4252 
  4253 * system: support for persistent Proof General sessions (refrain from
  4254 outdating all loaded theories on startup); user may create writable
  4255 logic images like this: ``isabelle -q HOL Test'';
  4256 
  4257 * system: smart selection of Isabelle process versus Isabelle
  4258 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4259 run both "isabelle" and "Isabelle" even if file names are badly
  4260 damaged (executable inspects the case of the first letter of its own
  4261 name); added separate "isabelle-process" and "isabelle-interface";
  4262 
  4263 * system: refrain from any attempt at filtering input streams; no
  4264 longer support ``8bit'' encoding of old isabelle font, instead proper
  4265 iso-latin characters may now be used; the related isatools
  4266 "symbolinput" and "nonascii" have disappeared as well;
  4267 
  4268 * system: removed old "xterm" interface (the print modes "xterm" and
  4269 "xterm_color" are still available for direct use in a suitable
  4270 terminal);
  4271 
  4272 
  4273 
  4274 New in Isabelle99-2 (February 2001)
  4275 -----------------------------------
  4276 
  4277 *** Overview of INCOMPATIBILITIES ***
  4278 
  4279 * HOL: please note that theories in the Library and elsewhere often use the
  4280 new-style (Isar) format; to refer to their theorems in an ML script you must
  4281 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4282 
  4283 * HOL: inductive package no longer splits induction rule aggressively,
  4284 but only as far as specified by the introductions given; the old
  4285 format may be recovered via ML function complete_split_rule or attribute
  4286 'split_rule (complete)';
  4287 
  4288 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4289 gfp_Tarski to gfp_unfold;
  4290 
  4291 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4292 
  4293 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4294 relation); infix "^^" has been renamed "``"; infix "``" has been
  4295 renamed "`"; "univalent" has been renamed "single_valued";
  4296 
  4297 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4298 operation;
  4299 
  4300 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4301 
  4302 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4303 
  4304 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4305 consequence, it is no longer monotonic wrt. the local goal context
  4306 (which is now passed through the inductive cases);
  4307 
  4308 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4309 \<gg> to \<ggreater>;
  4310 
  4311 
  4312 *** Document preparation ***
  4313 
  4314 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4315 available: are "it" for near math-mode best-style output, "sl" for
  4316 slanted text style, and "tt" for plain type-writer; if no
  4317 \isabellestyle command is given, output is according to slanted
  4318 type-writer);
  4319 
  4320 * support sub/super scripts (for single symbols only), input syntax is
  4321 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4322 
  4323 * some more standard symbols; see Appendix A of the system manual for
  4324 the complete list of symbols defined in isabellesym.sty;
  4325 
  4326 * improved isabelle style files; more abstract symbol implementation
  4327 (should now use \isamath{...} and \isatext{...} in custom symbol
  4328 definitions);
  4329 
  4330 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4331 state; Note that presentation of goal states does not conform to
  4332 actual human-readable proof documents.  Please do not include goal
  4333 states into document output unless you really know what you are doing!
  4334 
  4335 * proper indentation of antiquoted output with proportional LaTeX
  4336 fonts;
  4337 
  4338 * no_document ML operator temporarily disables LaTeX document
  4339 generation;
  4340 
  4341 * isatool unsymbolize tunes sources for plain ASCII communication;
  4342 
  4343 
  4344 *** Isar ***
  4345 
  4346 * Pure: Isar now suffers initial goal statements to contain unbound
  4347 schematic variables (this does not conform to actual readable proof
  4348 documents, due to unpredictable outcome and non-compositional proof
  4349 checking); users who know what they are doing may use schematic goals
  4350 for Prolog-style synthesis of proven results;
  4351 
  4352 * Pure: assumption method (an implicit finishing) now handles actual
  4353 rules as well;
  4354 
  4355 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4356 initial goal, declare "that" only as Pure intro (only for single
  4357 steps); the "that" rule assumption may now be involved in implicit
  4358 finishing, thus ".." becomes a feasible for trivial obtains;
  4359 
  4360 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4361 instance proofs may be performed by "..";
  4362 
  4363 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4364 statements as well;
  4365 
  4366 * Pure: more robust selection of calculational rules;
  4367 
  4368 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4369 rule (as well as the assumption rule);
  4370 
  4371 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4372 lemmas, using the graph browser tool;
  4373 
  4374 * Pure: predict failure of "show" in interactive mode;
  4375 
  4376 * Pure: 'thms_containing' now takes actual terms as arguments;
  4377 
  4378 * HOL: improved method 'induct' --- now handles non-atomic goals
  4379 (potential INCOMPATIBILITY); tuned error handling;
  4380 
  4381 * HOL: cases and induct rules now provide explicit hints about the
  4382 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4383 any remaining facts are inserted into the goal verbatim;
  4384 
  4385 * HOL: local contexts (aka cases) may now contain term bindings as
  4386 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4387 the result to be shown in each case;
  4388 
  4389 * HOL: added 'recdef_tc' command;
  4390 
  4391 * isatool convert assists in eliminating legacy ML scripts;
  4392 
  4393 
  4394 *** HOL ***
  4395 
  4396 * HOL/Library: a collection of generic theories to be used together
  4397 with main HOL; the theory loader path already includes this directory
  4398 by default; the following existing theories have been moved here:
  4399 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4400 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4401 
  4402 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4403 modelling and verification task performed in Isabelle/HOL +
  4404 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4405 
  4406 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4407 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4408 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4409 'domain', this makes the theory consistent with mathematical
  4410 literature;
  4411 
  4412 * HOL basics: added overloaded operations "inverse" and "divide"
  4413 (infix "/"), syntax for generic "abs" operation, generic summation
  4414 operator \<Sum>;
  4415 
  4416 * HOL/typedef: simplified package, provide more useful rules (see also
  4417 HOL/subset.thy);
  4418 
  4419 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4420 now expressed as a proper nested rule (old-style tactic scripts may
  4421 require atomize_strip_tac to cope with non-atomic premises);
  4422 
  4423 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4424 to "split_conv" (old name still available for compatibility);
  4425 
  4426 * HOL: improved concrete syntax for strings (e.g. allows translation
  4427 rules with string literals);
  4428 
  4429 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4430  and Fleuriot's mechanization of analysis, including the transcendental
  4431  functions for the reals;
  4432 
  4433 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4434 
  4435 
  4436 *** CTT ***
  4437 
  4438 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4439 "lam" is displayed as TWO lambda-symbols
  4440 
  4441 * CTT: theory Main now available, containing everything (that is, Bool
  4442 and Arith);
  4443 
  4444 
  4445 *** General ***
  4446 
  4447 * Pure: the Simplifier has been implemented properly as a derived rule
  4448 outside of the actual kernel (at last!); the overall performance
  4449 penalty in practical applications is about 50%, while reliability of
  4450 the Isabelle inference kernel has been greatly improved;
  4451 
  4452 * print modes "brackets" and "no_brackets" control output of nested =>
  4453 (types) and ==> (props); the default behaviour is "brackets";
  4454 
  4455 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4456 as assumptions as well;
  4457 
  4458 * system: support Poly/ML 4.0;
  4459 
  4460 * system: isatool install handles KDE version 1 or 2;
  4461 
  4462 
  4463 
  4464 New in Isabelle99-1 (October 2000)
  4465 ----------------------------------
  4466 
  4467 *** Overview of INCOMPATIBILITIES ***
  4468 
  4469 * HOL: simplification of natural numbers is much changed; to partly
  4470 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4471 issue the following ML commands:
  4472 
  4473   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4474   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4475 
  4476 * HOL: simplification no longer dives into case-expressions; this is
  4477 controlled by "t.weak_case_cong" for each datatype t;
  4478 
  4479 * HOL: nat_less_induct renamed to less_induct;
  4480 
  4481 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4482 fixsome to patch .thy and .ML sources automatically;
  4483 
  4484   select_equality  -> some_equality
  4485   select_eq_Ex     -> some_eq_ex
  4486   selectI2EX       -> someI2_ex
  4487   selectI2         -> someI2
  4488   selectI          -> someI
  4489   select1_equality -> some1_equality
  4490   Eps_sym_eq       -> some_sym_eq_trivial
  4491   Eps_eq           -> some_eq_trivial
  4492 
  4493 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4494 
  4495 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4496 instead);
  4497 
  4498 * HOL: the recursion equations generated by 'recdef' are now called
  4499 f.simps instead of f.rules;
  4500 
  4501 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4502 
  4503 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4504 sometimes be needed;
  4505 
  4506 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4507 
  4508 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4509 
  4510 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4511 product is now "<*>" instead of "Times"; the lexicographic product is
  4512 now "<*lex*>" instead of "**";
  4513 
  4514 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4515 of main HOL, but was unused); better use HOL's datatype package;
  4516 
  4517 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4518 the old syntax may be recovered as follows:
  4519 
  4520   syntax (symbols)
  4521     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4522       (infixl "\\<oplus>" 100)
  4523 
  4524 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4525 
  4526 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4527 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4528 internally;
  4529 
  4530 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4531 changed from A/r to A//r;
  4532 
  4533 * ZF: new treatment of arithmetic (nat & int) may break some old
  4534 proofs;
  4535 
  4536 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4537 rulify -> rule_format, elimify -> elim_format, ...);
  4538 
  4539 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4540 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4541 should have to change intro!! to intro? only); replaced "delrule" by
  4542 "rule del";
  4543 
  4544 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4545 
  4546 * Provers: strengthened force_tac by using new first_best_tac;
  4547 
  4548 * LaTeX document preparation: several changes of isabelle.sty (see
  4549 lib/texinputs);
  4550 
  4551 
  4552 *** Document preparation ***
  4553 
  4554 * formal comments (text blocks etc.) in new-style theories may now
  4555 contain antiquotations of thm/prop/term/typ/text to be presented
  4556 according to latex print mode; concrete syntax is like this:
  4557 @{term[show_types] "f(x) = a + x"};
  4558 
  4559 * isatool mkdir provides easy setup of Isabelle session directories,
  4560 including proper document sources;
  4561 
  4562 * generated LaTeX sources are now deleted after successful run
  4563 (isatool document -c); may retain a copy somewhere else via -D option
  4564 of isatool usedir;
  4565 
  4566 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4567 style files, achieving self-contained LaTeX sources and simplifying
  4568 LaTeX debugging;
  4569 
  4570 * old-style theories now produce (crude) LaTeX output as well;
  4571 
  4572 * browser info session directories are now self-contained (may be put
  4573 on WWW server seperately); improved graphs of nested sessions; removed
  4574 graph for 'all sessions';
  4575 
  4576 * several improvements in isabelle style files; \isabellestyle{it}
  4577 produces fake math mode output; \isamarkupheader is now \section by
  4578 default; see lib/texinputs/isabelle.sty etc.;
  4579 
  4580 
  4581 *** Isar ***
  4582 
  4583 * Isar/Pure: local results and corresponding term bindings are now
  4584 subject to Hindley-Milner polymorphism (similar to ML); this
  4585 accommodates incremental type-inference very nicely;
  4586 
  4587 * Isar/Pure: new derived language element 'obtain' supports
  4588 generalized existence reasoning;
  4589 
  4590 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4591 support accumulation of results, without applying any rules yet;
  4592 useful to collect intermediate results without explicit name
  4593 references, and for use with transitivity rules with more than 2
  4594 premises;
  4595 
  4596 * Isar/Pure: scalable support for case-analysis type proofs: new
  4597 'case' language element refers to local contexts symbolically, as
  4598 produced by certain proof methods; internally, case names are attached
  4599 to theorems as "tags";
  4600 
  4601 * Isar/Pure: theory command 'hide' removes declarations from
  4602 class/type/const name spaces;
  4603 
  4604 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4605 indicate potential overloading;
  4606 
  4607 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4608 
  4609 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4610 "{a,b,c}" instead of {a,b,c};
  4611 
  4612 * Isar/Pure now provides its own version of intro/elim/dest
  4613 attributes; useful for building new logics, but beware of confusion
  4614 with the version in Provers/classical;
  4615 
  4616 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4617 case name 'antecedent';
  4618 
  4619 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4620 to the current context is now done automatically);
  4621 
  4622 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4623 for definining proof methods in ML;
  4624 
  4625 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4626 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4627 most cases, one should have to change intro!! to intro? only);
  4628 replaced "delrule" by "rule del";
  4629 
  4630 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4631 'symmetric' attribute (the latter supercedes [RS sym]);
  4632 
  4633 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4634 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4635 well (including splits);
  4636 
  4637 * Isar/Provers: Simplifier and Classical methods now support all kind
  4638 of modifiers used in the past, including 'cong', 'iff', etc.
  4639 
  4640 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4641 of Simplifier and Classical reasoner);
  4642 
  4643 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4644 now support named cases; major packages (inductive, datatype, primrec,
  4645 recdef) support case names and properly name parameters;
  4646 
  4647 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4648 monotonicity conditions are extracted to be proven at end of
  4649 calculations;
  4650 
  4651 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4652 method anyway;
  4653 
  4654 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4655 split_if split_if_asm; datatype package provides theorems foo.splits =
  4656 foo.split foo.split_asm for each datatype;
  4657 
  4658 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4659 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4660 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4661 use "(cases (simplified))" method in proper proof texts);
  4662 
  4663 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4664 
  4665 * Isar: names of theorems etc. may be natural numbers as well;
  4666 
  4667 * Isar: 'pr' command: optional arguments for goals_limit and
  4668 ProofContext.prems_limit; no longer prints theory contexts, but only
  4669 proof states;
  4670 
  4671 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4672 additional print modes to be specified; e.g. "pr(latex)" will print
  4673 proof state according to the Isabelle LaTeX style;
  4674 
  4675 * Isar: improved support for emulating tactic scripts, including proof
  4676 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4677 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4678 (for HOL datatypes);
  4679 
  4680 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4681 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4682 'proof method scripts' have to be in depth-first order;
  4683 
  4684 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4685 
  4686 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4687 should instead use individual commands for printing items
  4688 (print_commands, print_methods etc.);
  4689 
  4690 * Isar: added 'nothing' --- the empty list of theorems;
  4691 
  4692 
  4693 *** HOL ***
  4694 
  4695 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4696 corresponding virtual machine and a specification of its bytecode
  4697 verifier and a lightweight bytecode verifier, including proofs of
  4698 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4699 Cornelia Pusch (see also the homepage of project Bali at
  4700 http://isabelle.in.tum.de/Bali/);
  4701 
  4702 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4703 Clemens Ballarin;
  4704 
  4705 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4706 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4707 Rasmussen;
  4708 
  4709 * HOL/Lattice: fundamental concepts of lattice theory and order
  4710 structures, including duals, properties of bounds versus algebraic
  4711 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4712 Theorem for complete lattices etc.; may also serve as a demonstration
  4713 for abstract algebraic reasoning using axiomatic type classes, and
  4714 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4715 
  4716 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4717 von Oheimb;
  4718 
  4719 * HOL/IMPP: extension of IMP with local variables and mutually
  4720 recursive procedures, by David von Oheimb;
  4721 
  4722 * HOL/Lambda: converted into new-style theory and document;
  4723 
  4724 * HOL/ex/Multiquote: example of multiple nested quotations and
  4725 anti-quotations -- basically a generalized version of de-Bruijn
  4726 representation; very useful in avoiding lifting of operations;
  4727 
  4728 * HOL/record: added general record equality rule to simpset; fixed
  4729 select-update simplification procedure to handle extended records as
  4730 well; admit "r" as field name;
  4731 
  4732 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4733 other numeric types and also as the identity of groups, rings, etc.;
  4734 
  4735 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4736 Types nat and int belong to this axclass;
  4737 
  4738 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4739    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4740    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4741   two terms #m*u and #n*u are replaced by #(m+n)*u
  4742     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4743   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4744     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4745 
  4746 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4747 powerful prover for predicate logic but knows nothing of clasets; see
  4748 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4749 
  4750 * HOL: new version of "case_tac" subsumes both boolean case split and
  4751 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4752 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4753 
  4754 * HOL: simplification no longer dives into case-expressions: only the
  4755 selector expression is simplified, but not the remaining arms; to
  4756 enable full simplification of case-expressions for datatype t, you may
  4757 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4758 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4759 
  4760 * HOL/recdef: the recursion equations generated by 'recdef' for
  4761 function 'f' are now called f.simps instead of f.rules; if all
  4762 termination conditions are proved automatically, these simplification
  4763 rules are added to the simpset, as in primrec; rules may be named
  4764 individually as well, resulting in a separate list of theorems for
  4765 each equation;
  4766 
  4767 * HOL/While is a new theory that provides a while-combinator. It
  4768 permits the definition of tail-recursive functions without the
  4769 provision of a termination measure. The latter is necessary once the
  4770 invariant proof rule for while is applied.
  4771 
  4772 * HOL: new (overloaded) notation for the set of elements below/above
  4773 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4774 
  4775 * HOL: theorems impI, allI, ballI bound as "strip";
  4776 
  4777 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4778 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4779 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4780 
  4781 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4782 
  4783 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4784 main HOL, but was unused);
  4785 
  4786 * HOL: fewer consts declared as global (e.g. have to refer to
  4787 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4788 
  4789 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4790 in case of overlap with user translations (e.g. judgements over
  4791 tuples); (note that the underlying logical represenation is still
  4792 bogus);
  4793 
  4794 
  4795 *** ZF ***
  4796 
  4797 * ZF: simplification automatically cancels common terms in arithmetic
  4798 expressions over nat and int;
  4799 
  4800 * ZF: new treatment of nat to minimize type-checking: all operators
  4801 coerce their operands to a natural number using the function natify,
  4802 making the algebraic laws unconditional;
  4803 
  4804 * ZF: as above, for int: operators coerce their operands to an integer
  4805 using the function intify;
  4806 
  4807 * ZF: the integer library now contains many of the usual laws for the
  4808 orderings, including $<=, and monotonicity laws for $+ and $*;
  4809 
  4810 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4811 simplification;
  4812 
  4813 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4814 to the simplifier and classical reasoner simultaneously;
  4815 
  4816 
  4817 *** General ***
  4818 
  4819 * Provers: blast_tac now handles actual object-logic rules as
  4820 assumptions; note that auto_tac uses blast_tac internally as well;
  4821 
  4822 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4823 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4824 
  4825 * Provers: delrules now handles destruct rules as well (no longer need
  4826 explicit make_elim);
  4827 
  4828 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  4829   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4830 use instead the strong form,
  4831   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  4832 in HOL, FOL and ZF the function cla_make_elim will create such rules
  4833 from destruct-rules;
  4834 
  4835 * Provers: Simplifier.easy_setup provides a fast path to basic
  4836 Simplifier setup for new object-logics;
  4837 
  4838 * Pure: AST translation rules no longer require constant head on LHS;
  4839 
  4840 * Pure: improved name spaces: ambiguous output is qualified; support
  4841 for hiding of names;
  4842 
  4843 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  4844 XSYMBOL_HOME; no longer need to do manual configuration in most
  4845 situations;
  4846 
  4847 * system: compression of ML heaps images may now be controlled via -c
  4848 option of isabelle and isatool usedir (currently only observed by
  4849 Poly/ML);
  4850 
  4851 * system: isatool installfonts may handle X-Symbol fonts as well (very
  4852 useful for remote X11);
  4853 
  4854 * system: provide TAGS file for Isabelle sources;
  4855 
  4856 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  4857 order;
  4858 
  4859 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  4860 timing flag supersedes proof_timing and Toplevel.trace;
  4861 
  4862 * ML: new combinators |>> and |>>> for incremental transformations
  4863 with secondary results (e.g. certain theory extensions):
  4864 
  4865 * ML: PureThy.add_defs gets additional argument to indicate potential
  4866 overloading (usually false);
  4867 
  4868 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  4869 results;
  4870 
  4871 
  4872 
  4873 New in Isabelle99 (October 1999)
  4874 --------------------------------
  4875 
  4876 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4877 
  4878 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  4879 are no longer simplified.  (This allows the simplifier to unfold recursive
  4880 functional programs.)  To restore the old behaviour, declare
  4881 
  4882     Delcongs [if_weak_cong];
  4883 
  4884 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  4885 complement;
  4886 
  4887 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  4888 
  4889 * HOL/datatype: mutual_induct_tac no longer exists --
  4890   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  4891 
  4892 * HOL/typedef: fixed type inference for representing set; type
  4893 arguments now have to occur explicitly on the rhs as type constraints;
  4894 
  4895 * ZF: The con_defs part of an inductive definition may no longer refer
  4896 to constants declared in the same theory;
  4897 
  4898 * HOL, ZF: the function mk_cases, generated by the inductive
  4899 definition package, has lost an argument.  To simplify its result, it
  4900 uses the default simpset instead of a supplied list of theorems.
  4901 
  4902 * HOL/List: the constructors of type list are now Nil and Cons;
  4903 
  4904 * Simplifier: the type of the infix ML functions
  4905         setSSolver addSSolver setSolver addSolver
  4906 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  4907 for packaging solvers. A solver is created via
  4908         mk_solver: string -> (thm list -> int -> tactic) -> solver
  4909 where the string argument is only a comment.
  4910 
  4911 
  4912 *** Proof tools ***
  4913 
  4914 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  4915 decision procedure for linear arithmetic. Currently it is used for
  4916 types `nat', `int', and `real' in HOL (see below); it can, should and
  4917 will be instantiated for other types and logics as well.
  4918 
  4919 * The simplifier now accepts rewrite rules with flexible heads, eg
  4920      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  4921   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  4922   matching.
  4923 
  4924 
  4925 *** General ***
  4926 
  4927 * New Isabelle/Isar subsystem provides an alternative to traditional
  4928 tactical theorem proving; together with the ProofGeneral/isar user
  4929 interface it offers an interactive environment for developing human
  4930 readable proof documents (Isar == Intelligible semi-automated
  4931 reasoning); for further information see isatool doc isar-ref,
  4932 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  4933 
  4934 * improved and simplified presentation of theories: better HTML markup
  4935 (including colors), graph views in several sizes; isatool usedir now
  4936 provides a proper interface for user theories (via -P option); actual
  4937 document preparation based on (PDF)LaTeX is available as well (for
  4938 new-style theories only); see isatool doc system for more information;
  4939 
  4940 * native support for Proof General, both for classic Isabelle and
  4941 Isabelle/Isar;
  4942 
  4943 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  4944 using the graph browser tool;
  4945 
  4946 * Isabelle manuals now also available as PDF;
  4947 
  4948 * theory loader rewritten from scratch (may not be fully
  4949 bug-compatible); old loadpath variable has been replaced by show_path,
  4950 add_path, del_path, reset_path functions; new operations such as
  4951 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  4952 isatool doc ref);
  4953 
  4954 * improved isatool install: option -k creates KDE application icon,
  4955 option -p DIR installs standalone binaries;
  4956 
  4957 * added ML_PLATFORM setting (useful for cross-platform installations);
  4958 more robust handling of platform specific ML images for SML/NJ;
  4959 
  4960 * the settings environment is now statically scoped, i.e. it is never
  4961 created again in sub-processes invoked from isabelle, isatool, or
  4962 Isabelle;
  4963 
  4964 * path element specification '~~' refers to '$ISABELLE_HOME';
  4965 
  4966 * in locales, the "assumes" and "defines" parts may be omitted if
  4967 empty;
  4968 
  4969 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4970 long arrows);
  4971 
  4972 * new print_mode "HTML";
  4973 
  4974 * new flag show_tags controls display of tags of theorems (which are
  4975 basically just comments that may be attached by some tools);
  4976 
  4977 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4978 mode and goal output format:
  4979 
  4980 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4981 244c244
  4982 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4983 ---
  4984 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4985 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4986 181c181
  4987 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4988 ---
  4989 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4990 
  4991 * function bind_thms stores lists of theorems (cf. bind_thm);
  4992 
  4993 * new shorthand tactics ftac, eatac, datac, fatac;
  4994 
  4995 * qed (and friends) now accept "" as result name; in that case the
  4996 theorem is not stored, but proper checks and presentation of the
  4997 result still apply;
  4998 
  4999 * theorem database now also indexes constants "Trueprop", "all",
  5000 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5001 
  5002 
  5003 *** HOL ***
  5004 
  5005 ** HOL arithmetic **
  5006 
  5007 * There are now decision procedures for linear arithmetic over nat and
  5008 int:
  5009 
  5010 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5011 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5012 are treated as atomic; subformulae not involving type `nat' or `int'
  5013 are ignored; quantified subformulae are ignored unless they are
  5014 positive universal or negative existential. The tactic has to be
  5015 invoked by hand and can be a little bit slow. In particular, the
  5016 running time is exponential in the number of occurrences of `min' and
  5017 `max', and `-' on `nat'.
  5018 
  5019 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5020 (negated) (in)equalities among the premises and the conclusion into
  5021 account (i.e. no compound formulae) and does not know about `min' and
  5022 `max', and `-' on `nat'. It is fast and is used automatically by the
  5023 simplifier.
  5024 
  5025 NB: At the moment, these decision procedures do not cope with mixed
  5026 nat/int formulae where the two parts interact, such as `m < n ==>
  5027 int(m) < int(n)'.
  5028 
  5029 * HOL/Numeral provides a generic theory of numerals (encoded
  5030 efficiently as bit strings); setup for types nat/int/real is in place;
  5031 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5032 int, existing theories and proof scripts may require a few additional
  5033 type constraints;
  5034 
  5035 * integer division and remainder can now be performed on constant
  5036 arguments;
  5037 
  5038 * many properties of integer multiplication, division and remainder
  5039 are now available;
  5040 
  5041 * An interface to the Stanford Validity Checker (SVC) is available through the
  5042 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5043 are proved automatically.  SVC must be installed separately, and its results
  5044 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5045 invocation of the underlying oracle).  For SVC see
  5046   http://verify.stanford.edu/SVC
  5047 
  5048 * IsaMakefile: the HOL-Real target now builds an actual image;
  5049 
  5050 
  5051 ** HOL misc **
  5052 
  5053 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5054 (in Isabelle/Isar) -- by Gertrud Bauer;
  5055 
  5056 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5057 analysis for assembly languages with subtypes;
  5058 
  5059 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5060 -- avoids syntactic ambiguities and treats state, transition, and
  5061 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5062 changed syntax and (many) tactics;
  5063 
  5064 * HOL/inductive: Now also handles more general introduction rules such
  5065   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5066   theorems are now maintained within the theory (maintained via the
  5067   "mono" attribute);
  5068 
  5069 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5070   (using function types) such as
  5071 
  5072   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5073 
  5074 * HOL/record: record_simproc (part of the default simpset) takes care
  5075 of selectors applied to updated records; record_split_tac is no longer
  5076 part of the default claset; update_defs may now be removed from the
  5077 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5078 
  5079   claset_ref () := claset() addSWrapper record_split_wrapper;
  5080   Delsimprocs [record_simproc]
  5081 
  5082 * HOL/typedef: fixed type inference for representing set; type
  5083 arguments now have to occur explicitly on the rhs as type constraints;
  5084 
  5085 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5086 names rather than an ML expression;
  5087 
  5088 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5089 supplied later.  Program schemes can be defined, such as
  5090     "While B C s = (if B s then While B C (C s) else s)"
  5091 where the well-founded relation can be chosen after B and C have been given.
  5092 
  5093 * HOL/List: the constructors of type list are now Nil and Cons;
  5094 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5095 course, ML tools referring to List.list.op # etc. have to be adapted;
  5096 
  5097 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5098 disabled by default; run isabelle with option -m HOL to get back to
  5099 the original Gordon/HOL-style output;
  5100 
  5101 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5102 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5103 
  5104 * HOL basic syntax simplified (more orthogonal): all variants of
  5105 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5106 Eps operator is provided as well: "SOME x. P[x]";
  5107 
  5108 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5109 
  5110 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5111 thus available for user theories;
  5112 
  5113 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5114 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5115 time;
  5116 
  5117 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5118 several times and then mp;
  5119 
  5120 
  5121 *** LK ***
  5122 
  5123 * the notation <<...>> is now available as a notation for sequences of
  5124 formulas;
  5125 
  5126 * the simplifier is now installed
  5127 
  5128 * the axiom system has been generalized (thanks to Soren Heilmann)
  5129 
  5130 * the classical reasoner now has a default rule database
  5131 
  5132 
  5133 *** ZF ***
  5134 
  5135 * new primrec section allows primitive recursive functions to be given
  5136 directly (as in HOL) over datatypes and the natural numbers;
  5137 
  5138 * new tactics induct_tac and exhaust_tac for induction (or case
  5139 analysis) over datatypes and the natural numbers;
  5140 
  5141 * the datatype declaration of type T now defines the recursor T_rec;
  5142 
  5143 * simplification automatically does freeness reasoning for datatype
  5144 constructors;
  5145 
  5146 * automatic type-inference, with AddTCs command to insert new
  5147 type-checking rules;
  5148 
  5149 * datatype introduction rules are now added as Safe Introduction rules
  5150 to the claset;
  5151 
  5152 * the syntax "if P then x else y" is now available in addition to
  5153 if(P,x,y);
  5154 
  5155 
  5156 *** Internal programming interfaces ***
  5157 
  5158 * tuned simplifier trace output; new flag debug_simp;
  5159 
  5160 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5161 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5162 
  5163 * AxClass.axclass_tac lost the theory argument;
  5164 
  5165 * tuned current_goals_markers semantics: begin / end goal avoids
  5166 printing empty lines;
  5167 
  5168 * removed prs and prs_fn hook, which was broken because it did not
  5169 include \n in its semantics, forcing writeln to add one
  5170 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5171 string -> unit if you really want to output text without newline;
  5172 
  5173 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5174 plain output, interface builders may have to enable 'isabelle_font'
  5175 mode to get Isabelle font glyphs as before;
  5176 
  5177 * refined token_translation interface; INCOMPATIBILITY: output length
  5178 now of type real instead of int;
  5179 
  5180 * theory loader actions may be traced via new ThyInfo.add_hook
  5181 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5182 your own database of information attached to *whole* theories -- as
  5183 opposed to intra-theory data slots offered via TheoryDataFun;
  5184 
  5185 * proper handling of dangling sort hypotheses (at last!);
  5186 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5187 extra sort hypotheses that can be witnessed from the type signature;
  5188 the force_strip_shyps flag is gone, any remaining shyps are simply
  5189 left in the theorem (with a warning issued by strip_shyps_warning);
  5190 
  5191 
  5192 
  5193 New in Isabelle98-1 (October 1998)
  5194 ----------------------------------
  5195 
  5196 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5197 
  5198 * several changes of automated proof tools;
  5199 
  5200 * HOL: major changes to the inductive and datatype packages, including
  5201 some minor incompatibilities of theory syntax;
  5202 
  5203 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5204 called `inj_on';
  5205 
  5206 * HOL: removed duplicate thms in Arith:
  5207   less_imp_add_less  should be replaced by  trans_less_add1
  5208   le_imp_add_le      should be replaced by  trans_le_add1
  5209 
  5210 * HOL: unary minus is now overloaded (new type constraints may be
  5211 required);
  5212 
  5213 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5214 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5215 now taken as an integer constant.
  5216 
  5217 * Pure: ML function 'theory_of' renamed to 'theory';
  5218 
  5219 
  5220 *** Proof tools ***
  5221 
  5222 * Simplifier:
  5223   1. Asm_full_simp_tac is now more aggressive.
  5224      1. It will sometimes reorient premises if that increases their power to
  5225         simplify.
  5226      2. It does no longer proceed strictly from left to right but may also
  5227         rotate premises to achieve further simplification.
  5228      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5229      old Asm_full_simp_tac in that it does not rotate premises.
  5230   2. The simplifier now knows a little bit about nat-arithmetic.
  5231 
  5232 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5233 allows for selected deletion of wrappers, by introduction of names for
  5234 wrapper functionals.  This implies that addbefore, addSbefore,
  5235 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5236 and that adding two tactics with the same name overwrites the first
  5237 one (emitting a warning).
  5238   type wrapper = (int -> tactic) -> (int -> tactic)
  5239   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5240   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5241   delWrapper, delSWrapper: claset *  string            -> claset
  5242   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5243 
  5244 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5245 semantics; addbefore now affects only the unsafe part of step_tac
  5246 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5247 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5248 by Force_tac;
  5249 
  5250 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5251 compWrapper; added safe wrapper (and access functions for it);
  5252 
  5253 * HOL/split_all_tac is now much faster and fails if there is nothing
  5254 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5255 and the names of the automatically generated variables have changed.
  5256 split_all_tac has moved within claset() from unsafe wrappers to safe
  5257 wrappers, which means that !!-bound variables are split much more
  5258 aggressively, and safe_tac and clarify_tac now split such variables.
  5259 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5260 Note: the same holds for record_split_tac, which does the job of
  5261 split_all_tac for record fields.
  5262 
  5263 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5264 permanently to the default simpset using Addsplits just like
  5265 Addsimps. They can be removed via Delsplits just like
  5266 Delsimps. Lower-case versions are also available.
  5267 
  5268 * HOL/Simplifier: The rule split_if is now part of the default
  5269 simpset. This means that the simplifier will eliminate all occurrences
  5270 of if-then-else in the conclusion of a goal. To prevent this, you can
  5271 either remove split_if completely from the default simpset by
  5272 `Delsplits [split_if]' or remove it in a specific call of the
  5273 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5274 other case splitting rules to/from the default simpset: every datatype
  5275 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5276 t is the name of the datatype).
  5277 
  5278 * Classical reasoner / Simplifier combination: new force_tac (and
  5279 derivatives Force_tac, force) combines rewriting and classical
  5280 reasoning (and whatever other tools) similarly to auto_tac, but is
  5281 aimed to solve the given subgoal completely.
  5282 
  5283 
  5284 *** General ***
  5285 
  5286 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5287 and `goalw': the theory is no longer needed as an explicit argument -
  5288 the current theory context is used; assumptions are no longer returned
  5289 at the ML-level unless one of them starts with ==> or !!; it is
  5290 recommended to convert to these new commands using isatool fixgoal
  5291 (backup your sources first!);
  5292 
  5293 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5294 the current theory context, and 'theory' to lookup stored theories;
  5295 
  5296 * new theory section 'locale' for declaring constants, assumptions and
  5297 definitions that have local scope;
  5298 
  5299 * new theory section 'nonterminals' for purely syntactic types;
  5300 
  5301 * new theory section 'setup' for generic ML setup functions
  5302 (e.g. package initialization);
  5303 
  5304 * the distribution now includes Isabelle icons: see
  5305 lib/logo/isabelle-{small,tiny}.xpm;
  5306 
  5307 * isatool install - install binaries with absolute references to
  5308 ISABELLE_HOME/bin;
  5309 
  5310 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5311 
  5312 * print mode 'emacs' reserved for Isamode;
  5313 
  5314 * support multiple print (ast) translations per constant name;
  5315 
  5316 * theorems involving oracles are now printed with a suffixed [!];
  5317 
  5318 
  5319 *** HOL ***
  5320 
  5321 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5322 
  5323 * HOL/inductive package reorganized and improved: now supports mutual
  5324 definitions such as
  5325 
  5326   inductive EVEN ODD
  5327     intrs
  5328       null "0 : EVEN"
  5329       oddI "n : EVEN ==> Suc n : ODD"
  5330       evenI "n : ODD ==> Suc n : EVEN"
  5331 
  5332 new theorem list "elims" contains an elimination rule for each of the
  5333 recursive sets; inductive definitions now handle disjunctive premises
  5334 correctly (also ZF);
  5335 
  5336 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5337 "mutual_induct" no longer exists - the induction rule is always
  5338 contained in "induct";
  5339 
  5340 
  5341 * HOL/datatype package re-implemented and greatly improved: now
  5342 supports mutually recursive datatypes such as
  5343 
  5344   datatype
  5345     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5346             | SUM ('a aexp) ('a aexp)
  5347             | DIFF ('a aexp) ('a aexp)
  5348             | NUM 'a
  5349   and
  5350     'a bexp = LESS ('a aexp) ('a aexp)
  5351             | AND ('a bexp) ('a bexp)
  5352             | OR ('a bexp) ('a bexp)
  5353 
  5354 as well as indirectly recursive datatypes such as
  5355 
  5356   datatype
  5357     ('a, 'b) term = Var 'a
  5358                   | App 'b ((('a, 'b) term) list)
  5359 
  5360 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5361 induction on mutually / indirectly recursive datatypes.
  5362 
  5363 Primrec equations are now stored in theory and can be accessed via
  5364 <function_name>.simps.
  5365 
  5366 INCOMPATIBILITIES:
  5367 
  5368   - Theories using datatypes must now have theory Datatype as an
  5369     ancestor.
  5370   - The specific <typename>.induct_tac no longer exists - use the
  5371     generic induct_tac instead.
  5372   - natE has been renamed to nat.exhaust - use exhaust_tac
  5373     instead of res_inst_tac ... natE. Note that the variable
  5374     names in nat.exhaust differ from the names in natE, this
  5375     may cause some "fragile" proofs to fail.
  5376   - The theorems split_<typename>_case and split_<typename>_case_asm
  5377     have been renamed to <typename>.split and <typename>.split_asm.
  5378   - Since default sorts of type variables are now handled correctly,
  5379     some datatype definitions may have to be annotated with explicit
  5380     sort constraints.
  5381   - Primrec definitions no longer require function name and type
  5382     of recursive argument.
  5383 
  5384 Consider using isatool fixdatatype to adapt your theories and proof
  5385 scripts to the new package (backup your sources first!).
  5386 
  5387 
  5388 * HOL/record package: considerably improved implementation; now
  5389 includes concrete syntax for record types, terms, updates; theorems
  5390 for surjective pairing and splitting !!-bound record variables; proof
  5391 support is as follows:
  5392 
  5393   1) standard conversions (selectors or updates applied to record
  5394 constructor terms) are part of the standard simpset;
  5395 
  5396   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5397 made part of standard simpset and claset via addIffs;
  5398 
  5399   3) a tactic for record field splitting (record_split_tac) is part of
  5400 the standard claset (addSWrapper);
  5401 
  5402 To get a better idea about these rules you may retrieve them via
  5403 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5404 the name of your record type.
  5405 
  5406 The split tactic 3) conceptually simplifies by the following rule:
  5407 
  5408   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5409 
  5410 Thus any record variable that is bound by meta-all will automatically
  5411 blow up into some record constructor term, consequently the
  5412 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5413 solve record problems automatically.
  5414 
  5415 
  5416 * reorganized the main HOL image: HOL/Integ and String loaded by
  5417 default; theory Main includes everything;
  5418 
  5419 * automatic simplification of integer sums and comparisons, using cancellation;
  5420 
  5421 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5422 
  5423 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5424 
  5425 * many new identities for unions, intersections, set difference, etc.;
  5426 
  5427 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5428 called split_if, split_split, split_sum_case and split_nat_case (to go
  5429 with add/delsplits);
  5430 
  5431 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5432 (?x::unit) = (); this is made part of the default simpset, which COULD
  5433 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5434 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5435 unit_abs_eta_conv is added in order to counter the effect of
  5436 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5437 %u.f();
  5438 
  5439 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5440 makes more sense);
  5441 
  5442 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5443   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5444   disjointness reasoning but breaking a few old proofs.
  5445 
  5446 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5447 to 'converse' from 'inverse' (for compatibility with ZF and some
  5448 literature);
  5449 
  5450 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5451 the well-founded relation;
  5452 
  5453 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5454     Compl A.  The "Compl" syntax remains available as input syntax for this
  5455     release ONLY.
  5456 
  5457 * HOL/Update: new theory of function updates:
  5458     f(a:=b) == %x. if x=a then b else f x
  5459 may also be iterated as in f(a:=b,c:=d,...);
  5460 
  5461 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5462 
  5463 * HOL/List:
  5464   - new function list_update written xs[i:=v] that updates the i-th
  5465     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5466   - new function `upt' written [i..j(] which generates the list
  5467     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5468     bound write [i..j], which is a shorthand for [i..j+1(].
  5469   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5470 
  5471 * HOL/Arith:
  5472   - removed 'pred' (predecessor) function;
  5473   - generalized some theorems about n-1;
  5474   - many new laws about "div" and "mod";
  5475   - new laws about greatest common divisors (see theory ex/Primes);
  5476 
  5477 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5478 instead of "inverse";
  5479 
  5480 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5481   of the multiset ordering;
  5482 
  5483 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5484   (not included by default);
  5485 
  5486 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5487 
  5488 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5489   programs, i.e. different program variables may have different types.
  5490 
  5491 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5492   [previously, this check worked only if the rewrite rule was unconditional]
  5493   Now rew can involve either definitions or equalities (either == or =).
  5494 
  5495 
  5496 *** ZF ***
  5497 
  5498 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5499   only the theorems proved on ZF.ML;
  5500 
  5501 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5502   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5503   disjointness reasoning but breaking a few old proofs.
  5504 
  5505 * ZF/Update: new theory of function updates
  5506     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5507   may also be iterated as in f(a:=b,c:=d,...);
  5508 
  5509 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5510 
  5511 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5512   [previously, this check worked only if the rewrite rule was unconditional]
  5513   Now rew can involve either definitions or equalities (either == or =).
  5514 
  5515 * case_tac provided for compatibility with HOL
  5516     (like the old excluded_middle_tac, but with subgoals swapped)
  5517 
  5518 
  5519 *** Internal programming interfaces ***
  5520 
  5521 * Pure: several new basic modules made available for general use, see
  5522 also src/Pure/README;
  5523 
  5524 * improved the theory data mechanism to support encapsulation (data
  5525 kind name replaced by private Object.kind, acting as authorization
  5526 key); new type-safe user interface via functor TheoryDataFun; generic
  5527 print_data function becomes basically useless;
  5528 
  5529 * removed global_names compatibility flag -- all theory declarations
  5530 are qualified by default;
  5531 
  5532 * module Pure/Syntax now offers quote / antiquote translation
  5533 functions (useful for Hoare logic etc. with implicit dependencies);
  5534 see HOL/ex/Antiquote for an example use;
  5535 
  5536 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5537 cterm -> thm;
  5538 
  5539 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5540 subgoal;
  5541 
  5542 * Display.print_goals function moved to Locale.print_goals;
  5543 
  5544 * standard print function for goals supports current_goals_markers
  5545 variable for marking begin of proof, end of proof, start of goal; the
  5546 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5547 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5548 for example;
  5549 
  5550 
  5551 
  5552 New in Isabelle98 (January 1998)
  5553 --------------------------------
  5554 
  5555 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5556 
  5557 * changed lexical syntax of terms / types: dots made part of long
  5558 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5559 
  5560 * simpset (and claset) reference variable replaced by functions
  5561 simpset / simpset_ref;
  5562 
  5563 * no longer supports theory aliases (via merge) and non-trivial
  5564 implicit merge of thms' signatures;
  5565 
  5566 * most internal names of constants changed due to qualified names;
  5567 
  5568 * changed Pure/Sequence interface (see Pure/seq.ML);
  5569 
  5570 
  5571 *** General Changes ***
  5572 
  5573 * hierachically structured name spaces (for consts, types, axms, thms
  5574 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5575 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5576 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5577 long_names for fully qualified output names; NOTE: ML programs
  5578 (special tactics, packages etc.) referring to internal names may have
  5579 to be adapted to cope with fully qualified names; in case of severe
  5580 backward campatibility problems try setting 'global_names' at compile
  5581 time to have enrything declared within a flat name space; one may also
  5582 fine tune name declarations in theories via the 'global' and 'local'
  5583 section;
  5584 
  5585 * reimplemented the implicit simpset and claset using the new anytype
  5586 data filed in signatures; references simpset:simpset ref etc. are
  5587 replaced by functions simpset:unit->simpset and
  5588 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5589 to patch your ML files accordingly;
  5590 
  5591 * HTML output now includes theory graph data for display with Java
  5592 applet or isatool browser; data generated automatically via isatool
  5593 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5594 
  5595 * defs may now be conditional; improved rewrite_goals_tac to handle
  5596 conditional equations;
  5597 
  5598 * defs now admits additional type arguments, using TYPE('a) syntax;
  5599 
  5600 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5601 creates a new theory node; implicit merge of thms' signatures is
  5602 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5603 transfer:theory->thm->thm in (rare) cases;
  5604 
  5605 * improved handling of draft signatures / theories; draft thms (and
  5606 ctyps, cterms) are automatically promoted to real ones;
  5607 
  5608 * slightly changed interfaces for oracles: admit many per theory, named
  5609 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5610 
  5611 * print_goals: optional output of const types (set show_consts and
  5612 show_types);
  5613 
  5614 * improved output of warnings (###) and errors (***);
  5615 
  5616 * subgoal_tac displays a warning if the new subgoal has type variables;
  5617 
  5618 * removed old README and Makefiles;
  5619 
  5620 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5621 
  5622 * removed obsolete init_pps and init_database;
  5623 
  5624 * deleted the obsolete tactical STATE, which was declared by
  5625     fun STATE tacfun st = tacfun st st;
  5626 
  5627 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5628 (which abbreviates $HOME);
  5629 
  5630 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5631 use isatool fixseq to adapt your ML programs (this works for fully
  5632 qualified references to the Sequence structure only!);
  5633 
  5634 * use_thy no longer requires writable current directory; it always
  5635 reloads .ML *and* .thy file, if either one is out of date;
  5636 
  5637 
  5638 *** Classical Reasoner ***
  5639 
  5640 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5641 tactics that use classical reasoning to simplify a subgoal without
  5642 splitting it into several subgoals;
  5643 
  5644 * Safe_tac: like safe_tac but uses the default claset;
  5645 
  5646 
  5647 *** Simplifier ***
  5648 
  5649 * added simplification meta rules:
  5650     (asm_)(full_)simplify: simpset -> thm -> thm;
  5651 
  5652 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5653 logics (again);
  5654 
  5655 * added prems argument to simplification procedures;
  5656 
  5657 * HOL, FOL, ZF: added infix function `addsplits':
  5658   instead of `<simpset> setloop (split_tac <thms>)'
  5659   you can simply write `<simpset> addsplits <thms>'
  5660 
  5661 
  5662 *** Syntax ***
  5663 
  5664 * TYPE('a) syntax for type reflection terms;
  5665 
  5666 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5667 
  5668 * pretty printer: changed order of mixfix annotation preference (again!);
  5669 
  5670 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5671 
  5672 
  5673 *** HOL ***
  5674 
  5675 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5676   with `addloop' of the simplifier to faciliate case splitting in premises.
  5677 
  5678 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5679 
  5680 * HOL/Auth: new protocol proofs including some for the Internet
  5681   protocol TLS;
  5682 
  5683 * HOL/Map: new theory of `maps' a la VDM;
  5684 
  5685 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5686 cancelling out common nat summands from =, <, <= (in)equalities, or
  5687 differences; simplification procedures nat_cancel_factor for
  5688 cancelling common factor from =, <, <= (in)equalities over natural
  5689 sums; nat_cancel contains both kinds of procedures, it is installed by
  5690 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5691 
  5692 * HOL/simplifier: terms of the form
  5693   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5694   are rewritten to
  5695   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5696   and those of the form
  5697   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5698   are rewritten to
  5699   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5700 
  5701 * HOL/datatype
  5702   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5703 
  5704   P(t_case f1 ... fn x) =
  5705      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5706         ...
  5707        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5708      )
  5709 
  5710   and a theorem `split_t_case_asm' of the form
  5711 
  5712   P(t_case f1 ... fn x) =
  5713     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5714         ...
  5715        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5716      )
  5717   which can be added to a simpset via `addsplits'. The existing theorems
  5718   expand_list_case and expand_option_case have been renamed to
  5719   split_list_case and split_option_case.
  5720 
  5721 * HOL/Arithmetic:
  5722   - `pred n' is automatically converted to `n-1'.
  5723     Users are strongly encouraged not to use `pred' any longer,
  5724     because it will disappear altogether at some point.
  5725   - Users are strongly encouraged to write "0 < n" rather than
  5726     "n ~= 0". Theorems and proof tools have been modified towards this
  5727     `standard'.
  5728 
  5729 * HOL/Lists:
  5730   the function "set_of_list" has been renamed "set" (and its theorems too);
  5731   the function "nth" now takes its arguments in the reverse order and
  5732   has acquired the infix notation "!" as in "xs!n".
  5733 
  5734 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5735 
  5736 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5737   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5738 
  5739 * HOL/record: extensible records with schematic structural subtyping
  5740 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5741 still lacks various theorems and concrete record syntax;
  5742 
  5743 
  5744 *** HOLCF ***
  5745 
  5746 * removed "axioms" and "generated by" sections;
  5747 
  5748 * replaced "ops" section by extended "consts" section, which is capable of
  5749   handling the continuous function space "->" directly;
  5750 
  5751 * domain package:
  5752   . proves theorems immediately and stores them in the theory,
  5753   . creates hierachical name space,
  5754   . now uses normal mixfix annotations (instead of cinfix...),
  5755   . minor changes to some names and values (for consistency),
  5756   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5757   . separator between mutual domain defs: changed "," to "and",
  5758   . improved handling of sort constraints;  now they have to
  5759     appear on the left-hand side of the equations only;
  5760 
  5761 * fixed LAM <x,y,zs>.b syntax;
  5762 
  5763 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5764 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5765 
  5766 
  5767 *** FOL and ZF ***
  5768 
  5769 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5770   with `addloop' of the simplifier to faciliate case splitting in premises.
  5771 
  5772 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5773 in HOL, they strip ALL and --> from proved theorems;
  5774 
  5775 
  5776 
  5777 New in Isabelle94-8 (May 1997)
  5778 ------------------------------
  5779 
  5780 *** General Changes ***
  5781 
  5782 * new utilities to build / run / maintain Isabelle etc. (in parts
  5783 still somewhat experimental); old Makefiles etc. still functional;
  5784 
  5785 * new 'Isabelle System Manual';
  5786 
  5787 * INSTALL text, together with ./configure and ./build scripts;
  5788 
  5789 * reimplemented type inference for greater efficiency, better error
  5790 messages and clean internal interface;
  5791 
  5792 * prlim command for dealing with lots of subgoals (an easier way of
  5793 setting goals_limit);
  5794 
  5795 
  5796 *** Syntax ***
  5797 
  5798 * supports alternative (named) syntax tables (parser and pretty
  5799 printer); internal interface is provided by add_modesyntax(_i);
  5800 
  5801 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5802 be used in conjunction with the Isabelle symbol font; uses the
  5803 "symbols" syntax table;
  5804 
  5805 * added token_translation interface (may translate name tokens in
  5806 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5807 the current print_mode); IMPORTANT: user print translation functions
  5808 are responsible for marking newly introduced bounds
  5809 (Syntax.mark_boundT);
  5810 
  5811 * token translations for modes "xterm" and "xterm_color" that display
  5812 names in bold, underline etc. or colors (which requires a color
  5813 version of xterm);
  5814 
  5815 * infixes may now be declared with names independent of their syntax;
  5816 
  5817 * added typed_print_translation (like print_translation, but may
  5818 access type of constant);
  5819 
  5820 
  5821 *** Classical Reasoner ***
  5822 
  5823 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5824 some limitations.  Blast_tac...
  5825   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5826   + ignores elimination rules that don't have the correct format
  5827         (the conclusion MUST be a formula variable)
  5828   + ignores types, which can make HOL proofs fail
  5829   + rules must not require higher-order unification, e.g. apply_type in ZF
  5830     [message "Function Var's argument not a bound variable" relates to this]
  5831   + its proof strategy is more general but can actually be slower
  5832 
  5833 * substitution with equality assumptions no longer permutes other
  5834 assumptions;
  5835 
  5836 * minor changes in semantics of addafter (now called addaltern); renamed
  5837 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  5838 (and access functions for it);
  5839 
  5840 * improved combination of classical reasoner and simplifier:
  5841   + functions for handling clasimpsets
  5842   + improvement of addss: now the simplifier is called _after_ the
  5843     safe steps.
  5844   + safe variant of addss called addSss: uses safe simplifications
  5845     _during_ the safe steps. It is more complete as it allows multiple
  5846     instantiations of unknowns (e.g. with slow_tac).
  5847 
  5848 *** Simplifier ***
  5849 
  5850 * added interface for simplification procedures (functions that
  5851 produce *proven* rewrite rules on the fly, depending on current
  5852 redex);
  5853 
  5854 * ordering on terms as parameter (used for ordered rewriting);
  5855 
  5856 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  5857 
  5858 * the solver is now split into a safe and an unsafe part.
  5859 This should be invisible for the normal user, except that the
  5860 functions setsolver and addsolver have been renamed to setSolver and
  5861 addSolver; added safe_asm_full_simp_tac;
  5862 
  5863 
  5864 *** HOL ***
  5865 
  5866 * a generic induction tactic `induct_tac' which works for all datatypes and
  5867 also for type `nat';
  5868 
  5869 * a generic case distinction tactic `exhaust_tac' which works for all
  5870 datatypes and also for type `nat';
  5871 
  5872 * each datatype comes with a function `size';
  5873 
  5874 * patterns in case expressions allow tuple patterns as arguments to
  5875 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  5876 
  5877 * primrec now also works with type nat;
  5878 
  5879 * recdef: a new declaration form, allows general recursive functions to be
  5880 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  5881 
  5882 * the constant for negation has been renamed from "not" to "Not" to
  5883 harmonize with FOL, ZF, LK, etc.;
  5884 
  5885 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  5886 infinite lists;
  5887 
  5888 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  5889 
  5890 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  5891 problems in commutative rings, using axiomatic type classes for + and *;
  5892 
  5893 * more examples in HOL/MiniML and HOL/Auth;
  5894 
  5895 * more default rewrite rules for quantifiers, union/intersection;
  5896 
  5897 * a new constant `arbitrary == @x.False';
  5898 
  5899 * HOLCF/IOA replaces old HOL/IOA;
  5900 
  5901 * HOLCF changes: derived all rules and arities
  5902   + axiomatic type classes instead of classes
  5903   + typedef instead of faking type definitions
  5904   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  5905   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  5906   + eliminated the types void, one, tr
  5907   + use unit lift and bool lift (with translations) instead of one and tr
  5908   + eliminated blift from Lift3.thy (use Def instead of blift)
  5909   all eliminated rules are derived as theorems --> no visible changes ;
  5910 
  5911 
  5912 *** ZF ***
  5913 
  5914 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  5915 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  5916 as ZF_cs addSIs [equalityI];
  5917 
  5918 
  5919 
  5920 New in Isabelle94-7 (November 96)
  5921 ---------------------------------
  5922 
  5923 * allowing negative levels (as offsets) in prlev and choplev;
  5924 
  5925 * super-linear speedup for large simplifications;
  5926 
  5927 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  5928 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  5929 FAIL); can suppress it using the command Delsimps (ex_simps @
  5930 all_simps); De Morgan laws are also now included, by default;
  5931 
  5932 * improved printing of ==>  :  ~:
  5933 
  5934 * new object-logic "Sequents" adds linear logic, while replacing LK
  5935 and Modal (thanks to Sara Kalvala);
  5936 
  5937 * HOL/Auth: correctness proofs for authentication protocols;
  5938 
  5939 * HOL: new auto_tac combines rewriting and classical reasoning (many
  5940 examples on HOL/Auth);
  5941 
  5942 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  5943 the rewriter and classical reasoner simultaneously;
  5944 
  5945 * function uresult no longer returns theorems in "standard" format;
  5946 regain previous version by: val uresult = standard o uresult;
  5947 
  5948 
  5949 
  5950 New in Isabelle94-6
  5951 -------------------
  5952 
  5953 * oracles -- these establish an interface between Isabelle and trusted
  5954 external reasoners, which may deliver results as theorems;
  5955 
  5956 * proof objects (in particular record all uses of oracles);
  5957 
  5958 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  5959 
  5960 * "constdefs" section in theory files;
  5961 
  5962 * "primrec" section (HOL) no longer requires names;
  5963 
  5964 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5965 
  5966 
  5967 
  5968 New in Isabelle94-5
  5969 -------------------
  5970 
  5971 * reduced space requirements;
  5972 
  5973 * automatic HTML generation from theories;
  5974 
  5975 * theory files no longer require "..." (quotes) around most types;
  5976 
  5977 * new examples, including two proofs of the Church-Rosser theorem;
  5978 
  5979 * non-curried (1994) version of HOL is no longer distributed;
  5980 
  5981 
  5982 
  5983 New in Isabelle94-4
  5984 -------------------
  5985 
  5986 * greatly reduced space requirements;
  5987 
  5988 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5989 
  5990 * searchable theorem database (see the section "Retrieving theorems" on
  5991 page 8 of the Reference Manual);
  5992 
  5993 * new examples, including Grabczewski's monumental case study of the
  5994 Axiom of Choice;
  5995 
  5996 * The previous version of HOL renamed to Old_HOL;
  5997 
  5998 * The new version of HOL (previously called CHOL) uses a curried syntax
  5999 for functions.  Application looks like f a b instead of f(a,b);
  6000 
  6001 * Mutually recursive inductive definitions finally work in HOL;
  6002 
  6003 * In ZF, pattern-matching on tuples is now available in all abstractions and
  6004 translates to the operator "split";
  6005 
  6006 
  6007 
  6008 New in Isabelle94-3
  6009 -------------------
  6010 
  6011 * new infix operator, addss, allowing the classical reasoner to
  6012 perform simplification at each step of its search.  Example:
  6013         fast_tac (cs addss ss)
  6014 
  6015 * a new logic, CHOL, the same as HOL, but with a curried syntax
  6016 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  6017 look like (a,b) instead of <a,b>;
  6018 
  6019 * PLEASE NOTE: CHOL will eventually replace HOL!
  6020 
  6021 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  6022 It translates to the operator "split".  A new theory of integers is available;
  6023 
  6024 * In ZF, integer numerals now denote two's-complement binary integers.
  6025 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  6026 
  6027 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  6028 of the Axiom of Choice;
  6029 
  6030 
  6031 
  6032 New in Isabelle94-2
  6033 -------------------
  6034 
  6035 * Significantly faster resolution;
  6036 
  6037 * the different sections in a .thy file can now be mixed and repeated
  6038 freely;
  6039 
  6040 * Database of theorems for FOL, HOL and ZF.  New
  6041 commands including qed, qed_goal and bind_thm store theorems in the database.
  6042 
  6043 * Simple database queries: return a named theorem (get_thm) or all theorems of
  6044 a given theory (thms_of), or find out what theory a theorem was proved in
  6045 (theory_of_thm);
  6046 
  6047 * Bugs fixed in the inductive definition and datatype packages;
  6048 
  6049 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  6050 and HOL_dup_cs obsolete;
  6051 
  6052 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  6053 have been removed;
  6054 
  6055 * Simpler definition of function space in ZF;
  6056 
  6057 * new results about cardinal and ordinal arithmetic in ZF;
  6058 
  6059 * 'subtype' facility in HOL for introducing new types as subsets of existing
  6060 types;
  6061 
  6062 :mode=text:wrap=hard:maxLineLen=72: