NEWS
author wenzelm
Sun Jul 26 22:33:32 2009 +0200 (2009-07-26)
changeset 32216 2f3d65d15149
parent 32151 2f65c45c2e7e
child 32217 420108dd7dfe
permissions -rw-r--r--
tacticals FOCUS and FOCUS_PARAMS;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * More convenient names for set intersection and union.  INCOMPATIBILITY:
    22 
    23     Set.Int ~>  Set.inter
    24     Set.Un ~>   Set.union
    25 
    26 * Code generator attributes follow the usual underscore convention:
    27     code_unfold     replaces    code unfold
    28     code_post       replaces    code post
    29     etc.
    30   INCOMPATIBILITY.
    31 
    32 * New quickcheck implementation using new code generator.
    33 
    34 * New type class boolean_algebra.
    35 
    36 * Refinements to lattices classes:
    37   - added boolean_algebra type class
    38   - less default intro/elim rules in locale variant, more default
    39     intro/elim rules in class variant: more uniformity
    40   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    41   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    42   - renamed ACI to inf_sup_aci
    43 
    44 * Class semiring_div requires superclass no_zero_divisors and proof of
    45 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    46 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    47 generalized to class semiring_div, subsuming former theorems
    48 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    49 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    50 INCOMPATIBILITY.
    51 
    52 * Power operations on relations and functions are now one dedicate
    53 constant compow with infix syntax "^^".  Power operations on
    54 multiplicative monoids retains syntax "^" and is now defined generic
    55 in class power.  INCOMPATIBILITY.
    56 
    57 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    58 infinite sets. It is shown that they form a complete lattice.
    59 
    60 * ML antiquotation @{code_datatype} inserts definition of a datatype
    61 generated by the code generator; see Predicate.thy for an example.
    62 
    63 * New method "linarith" invokes existing linear arithmetic decision
    64 procedure only.
    65 
    66 * Implementation of quickcheck using generic code generator; default
    67 generators are provided for all suitable HOL types, records and
    68 datatypes.
    69 
    70 * Constants Set.Pow and Set.image now with authentic syntax;
    71 object-logic definitions Set.Pow_def and Set.image_def.
    72 INCOMPATIBILITY.
    73 
    74 * Renamed theorems:
    75 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    76 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    77 Suc_plus1 -> Suc_eq_plus1
    78 
    79 * New sledgehammer option "Full Types" in Proof General settings menu.
    80 Causes full type information to be output to the ATPs.  This slows
    81 ATPs down considerably but eliminates a source of unsound "proofs"
    82 that fail later.
    83 
    84 * Discontinued ancient tradition to suffix certain ML module names
    85 with "_package", e.g.:
    86 
    87     DatatypePackage ~> Datatype
    88     InductivePackage ~> Inductive
    89 
    90     etc.
    91 
    92 INCOMPATIBILITY.
    93 
    94 * NewNumberTheory: Jeremy Avigad's new version of part of
    95 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
    96 
    97 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    98 
    99 * Abbreviation "arbitrary" of "undefined" has disappeared; use
   100 "undefined" directly.  INCOMPATIBILITY.
   101 
   102 * New evaluator "approximate" approximates an real valued term using
   103 the same method as the approximation method.
   104 
   105 * Method "approximate" supports now arithmetic expressions as
   106 boundaries of intervals and implements interval splitting and Taylor
   107 series expansion.
   108 
   109 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   110 the theorems in DERIV_intros assumes composition with an additional
   111 function and matches a variable to the derivative, which has to be
   112 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   113 the derivative of most elementary terms.
   114 
   115 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   116 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   117 
   118 
   119 *** ML ***
   120 
   121 * Tactical FOCUS is similar to SUBPROOF, but allows the body tactic to
   122 introduce new subgoals and schematic variables.  FOCUS_PARAMS is
   123 similar, but focuses on the parameter prefix only, leaving subgoal
   124 premises unchanged.
   125 
   126 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   127 functors have their own ML name space there is no point to mark them
   128 separately.)  Minor INCOMPATIBILITY.
   129 
   130 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   131 
   132 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   133 cominators for "args".  INCOMPATIBILITY, need to use simplified
   134 Attrib/Method.setup introduced in Isabelle2009.
   135 
   136 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   137 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   138 last resort.  INCOMPATIBILITY.
   139 
   140 * Display.pretty_thm now requires a proper context (cf. former
   141 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   142 or even Display.pretty_thm_without_context as last resort.
   143 INCOMPATIBILITY.
   144 
   145 
   146 *** System ***
   147 
   148 * Discontinued support for Poly/ML 4.x versions.
   149 
   150 * Removed "compress" option from isabelle-process and isabelle usedir;
   151 this is always enabled.
   152 
   153 * More fine-grained control of proof parallelism, cf.
   154 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   155 
   156 
   157 
   158 New in Isabelle2009 (April 2009)
   159 --------------------------------
   160 
   161 *** General ***
   162 
   163 * Simplified main Isabelle executables, with less surprises on
   164 case-insensitive file-systems (such as Mac OS).
   165 
   166   - The main Isabelle tool wrapper is now called "isabelle" instead of
   167     "isatool."
   168 
   169   - The former "isabelle" alias for "isabelle-process" has been
   170     removed (should rarely occur to regular users).
   171 
   172   - The former "isabelle-interface" and its alias "Isabelle" have been
   173     removed (interfaces are now regular Isabelle tools).
   174 
   175 Within scripts and make files, the Isabelle environment variables
   176 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   177 respectively.  (The latter are still available as legacy feature.)
   178 
   179 The old isabelle-interface wrapper could react in confusing ways if
   180 the interface was uninstalled or changed otherwise.  Individual
   181 interface tool configuration is now more explicit, see also the
   182 Isabelle system manual.  In particular, Proof General is now available
   183 via "isabelle emacs".
   184 
   185 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   186 purge installed copies of Isabelle executables and re-run "isabelle
   187 install -p ...", or use symlinks.
   188 
   189 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   190 old ~/isabelle, which was slightly non-standard and apt to cause
   191 surprises on case-insensitive file-systems (such as Mac OS).
   192 
   193 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   194 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   195 care is required when using older releases of Isabelle.  Note that
   196 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   197 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   198 
   199 * Proofs of fully specified statements are run in parallel on
   200 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   201 a regular 4-core machine, if the initial heap space is made reasonably
   202 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   203 
   204 * The main reference manuals ("isar-ref", "implementation", and
   205 "system") have been updated and extended.  Formally checked references
   206 as hyperlinks are now available uniformly.
   207 
   208 
   209 *** Pure ***
   210 
   211 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   212 respects.  The most important changes are listed below.  See the
   213 Tutorial on Locales ("locales" manual) for details.
   214 
   215 - In locale expressions, instantiation replaces renaming.  Parameters
   216 must be declared in a for clause.  To aid compatibility with previous
   217 parameter inheritance, in locale declarations, parameters that are not
   218 'touched' (instantiation position "_" or omitted) are implicitly added
   219 with their syntax at the beginning of the for clause.
   220 
   221 - Syntax from abbreviations and definitions in locales is available in
   222 locale expressions and context elements.  The latter is particularly
   223 useful in locale declarations.
   224 
   225 - More flexible mechanisms to qualify names generated by locale
   226 expressions.  Qualifiers (prefixes) may be specified in locale
   227 expressions, and can be marked as mandatory (syntax: "name!:") or
   228 optional (syntax "name?:").  The default depends for plain "name:"
   229 depends on the situation where a locale expression is used: in
   230 commands 'locale' and 'sublocale' prefixes are optional, in
   231 'interpretation' and 'interpret' prefixes are mandatory.  The old
   232 implicit qualifiers derived from the parameter names of a locale are
   233 no longer generated.
   234 
   235 - Command "sublocale l < e" replaces "interpretation l < e".  The
   236 instantiation clause in "interpretation" and "interpret" (square
   237 brackets) is no longer available.  Use locale expressions.
   238 
   239 - When converting proof scripts, mandatory qualifiers in
   240 'interpretation' and 'interpret' should be retained by default, even
   241 if this is an INCOMPATIBILITY compared to former behavior.  In the
   242 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   243 in locale expressions range over a single locale instance only.
   244 
   245 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   246 In existing theorem specifications replace the includes element by the
   247 respective context elements of the included locale, omitting those
   248 that are already present in the theorem specification.  Multiple
   249 assume elements of a locale should be replaced by a single one
   250 involving the locale predicate.  In the proof body, declarations (most
   251 notably theorems) may be regained by interpreting the respective
   252 locales in the proof context as required (command "interpret").
   253 
   254 If using "includes" in replacement of a target solely because the
   255 parameter types in the theorem are not as general as in the target,
   256 consider declaring a new locale with additional type constraints on
   257 the parameters (context element "constrains").
   258 
   259 - Discontinued "locale (open)".  INCOMPATIBILITY.
   260 
   261 - Locale interpretation commands no longer attempt to simplify goal.
   262 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   263 methods intro_locales and unfold_locales to clarify.
   264 
   265 - Locale interpretation commands no longer accept interpretation
   266 attributes.  INCOMPATIBILITY.
   267 
   268 * Class declaration: so-called "base sort" must not be given in import
   269 list any longer, but is inferred from the specification.  Particularly
   270 in HOL, write
   271 
   272     class foo = ...
   273 
   274 instead of
   275 
   276     class foo = type + ...
   277 
   278 * Class target: global versions of theorems stemming do not carry a
   279 parameter prefix any longer.  INCOMPATIBILITY.
   280 
   281 * Class 'instance' command no longer accepts attached definitions.
   282 INCOMPATIBILITY, use proper 'instantiation' target instead.
   283 
   284 * Recovered hiding of consts, which was accidentally broken in
   285 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   286 makes c inaccessible; consider using ``hide (open) const c'' instead.
   287 
   288 * Slightly more coherent Pure syntax, with updated documentation in
   289 isar-ref manual.  Removed locales meta_term_syntax and
   290 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   291 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   292 directly in regular applications.
   293 
   294 * There is a new syntactic category "float_const" for signed decimal
   295 fractions (e.g. 123.45 or -123.45).
   296 
   297 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   298 interface with 'setup' command instead.
   299 
   300 * Command 'local_setup' is similar to 'setup', but operates on a local
   301 theory context.
   302 
   303 * The 'axiomatization' command now only works within a global theory
   304 context.  INCOMPATIBILITY.
   305 
   306 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   307 hypotheses.  Sorts required in the course of reasoning need to be
   308 covered by the constraints in the initial statement, completed by the
   309 type instance information of the background theory.  Non-trivial sort
   310 hypotheses, which rarely occur in practice, may be specified via
   311 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   312 
   313   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   314 
   315 The result contains an implicit sort hypotheses as before --
   316 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   317 normalization.
   318 
   319 * Generalized Isar history, with support for linear undo, direct state
   320 addressing etc.
   321 
   322 * Changed defaults for unify configuration options:
   323 
   324   unify_trace_bound = 50 (formerly 25)
   325   unify_search_bound = 60 (formerly 30)
   326 
   327 * Different bookkeeping for code equations (INCOMPATIBILITY):
   328 
   329   a) On theory merge, the last set of code equations for a particular
   330      constant is taken (in accordance with the policy applied by other
   331      parts of the code generator framework).
   332 
   333   b) Code equations stemming from explicit declarations (e.g. code
   334      attribute) gain priority over default code equations stemming
   335      from definition, primrec, fun etc.
   336 
   337 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   338 
   339 * Unified theorem tables for both code generators.  Thus [code
   340 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   341 
   342 * Command 'find_consts' searches for constants based on type and name
   343 patterns, e.g.
   344 
   345     find_consts "_ => bool"
   346 
   347 By default, matching is against subtypes, but it may be restricted to
   348 the whole type.  Searching by name is possible.  Multiple queries are
   349 conjunctive and queries may be negated by prefixing them with a
   350 hyphen:
   351 
   352     find_consts strict: "_ => bool" name: "Int" -"int => int"
   353 
   354 * New 'find_theorems' criterion "solves" matches theorems that
   355 directly solve the current goal (modulo higher-order unification).
   356 
   357 * Auto solve feature for main theorem statements: whenever a new goal
   358 is stated, "find_theorems solves" is called; any theorems that could
   359 solve the lemma directly are listed as part of the goal state.
   360 Cf. associated options in Proof General Isabelle settings menu,
   361 enabled by default, with reasonable timeout for pathological cases of
   362 higher-order unification.
   363 
   364 
   365 *** Document preparation ***
   366 
   367 * Antiquotation @{lemma} now imitates a regular terminal proof,
   368 demanding keyword 'by' and supporting the full method expression
   369 syntax just like the Isar command 'by'.
   370 
   371 
   372 *** HOL ***
   373 
   374 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   375 points Main and Complex_Main remain as before.
   376 
   377 * Logic image HOL-Plain provides a minimal HOL with the most important
   378 tools available (inductive, datatype, primrec, ...).  This facilitates
   379 experimentation and tool development.  Note that user applications
   380 (and library theories) should never refer to anything below theory
   381 Main, as before.
   382 
   383 * Logic image HOL-Main stops at theory Main, and thus facilitates
   384 experimentation due to shorter build times.
   385 
   386 * Logic image HOL-NSA contains theories of nonstandard analysis which
   387 were previously part of former HOL-Complex.  Entry point Hyperreal
   388 remains valid, but theories formerly using Complex_Main should now use
   389 new entry point Hypercomplex.
   390 
   391 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   392 Posix processes.  Avoids potentially expensive forking of the ML
   393 process.  New thread-based implementation also works on non-Unix
   394 platforms (Cygwin).  Provers are no longer hardwired, but defined
   395 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   396 commands are covered in the isar-ref manual.
   397 
   398 * Wrapper scripts for remote SystemOnTPTP service allows to use
   399 sledgehammer without local ATP installation (Vampire etc.). Other
   400 provers may be included via suitable ML wrappers, see also
   401 src/HOL/ATP_Linkup.thy.
   402 
   403 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   404 menu.
   405 
   406 * The metis method no longer fails because the theorem is too trivial
   407 (contains the empty clause).
   408 
   409 * The metis method now fails in the usual manner, rather than raising
   410 an exception, if it determines that it cannot prove the theorem.
   411 
   412 * Method "coherent" implements a prover for coherent logic (see also
   413 src/Tools/coherent.ML).
   414 
   415 * Constants "undefined" and "default" replace "arbitrary".  Usually
   416 "undefined" is the right choice to replace "arbitrary", though
   417 logically there is no difference.  INCOMPATIBILITY.
   418 
   419 * Command "value" now integrates different evaluation mechanisms.  The
   420 result of the first successful evaluation mechanism is printed.  In
   421 square brackets a particular named evaluation mechanisms may be
   422 specified (currently, [SML], [code] or [nbe]).  See further
   423 src/HOL/ex/Eval_Examples.thy.
   424 
   425 * Normalization by evaluation now allows non-leftlinear equations.
   426 Declare with attribute [code nbe].
   427 
   428 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   429 as the structured Isar versions "cases" and "induct", cf. the
   430 corresponding "cases" and "induct" attributes.  Mutual induction rules
   431 are now presented as a list of individual projections
   432 (e.g. foo_bar.inducts for types foo and bar); the old format with
   433 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   434 rare situations a different rule is selected --- notably nested tuple
   435 elimination instead of former prod.exhaust: use explicit (case_tac t
   436 rule: prod.exhaust) here.
   437 
   438 * Attributes "cases", "induct", "coinduct" support "del" option.
   439 
   440 * Removed fact "case_split_thm", which duplicates "case_split".
   441 
   442 * The option datatype has been moved to a new theory Option.  Renamed
   443 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   444 
   445 * New predicate "strict_mono" classifies strict functions on partial
   446 orders.  With strict functions on linear orders, reasoning about
   447 (in)equalities is facilitated by theorems "strict_mono_eq",
   448 "strict_mono_less_eq" and "strict_mono_less".
   449 
   450 * Some set operations are now proper qualified constants with
   451 authentic syntax.  INCOMPATIBILITY:
   452 
   453     op Int ~>   Set.Int
   454     op Un ~>    Set.Un
   455     INTER ~>    Set.INTER
   456     UNION ~>    Set.UNION
   457     Inter ~>    Set.Inter
   458     Union ~>    Set.Union
   459     {} ~>       Set.empty
   460     UNIV ~>     Set.UNIV
   461 
   462 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   463 theory Set.
   464 
   465 * Auxiliary class "itself" has disappeared -- classes without any
   466 parameter are treated as expected by the 'class' command.
   467 
   468 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   469 
   470 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   471 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   472 
   473 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   474 method "approximation".  It proves formulas on real values by using
   475 interval arithmetic.  In the formulas are also the transcendental
   476 functions sin, cos, tan, atan, ln, exp and the constant pi are
   477 allowed. For examples see
   478 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   479 
   480 * Theory "Reflection" now resides in HOL/Library.
   481 
   482 * Entry point to Word library now simply named "Word".
   483 INCOMPATIBILITY.
   484 
   485 * Made source layout more coherent with logical distribution
   486 structure:
   487 
   488     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   489     src/HOL/Library/Code_Message.thy ~> src/HOL/
   490     src/HOL/Library/GCD.thy ~> src/HOL/
   491     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   492     src/HOL/Library/Parity.thy ~> src/HOL/
   493     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   494     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   495     src/HOL/Real/Lubs.thy ~> src/HOL/
   496     src/HOL/Real/PReal.thy ~> src/HOL/
   497     src/HOL/Real/Rational.thy ~> src/HOL/
   498     src/HOL/Real/RComplete.thy ~> src/HOL/
   499     src/HOL/Real/RealDef.thy ~> src/HOL/
   500     src/HOL/Real/RealPow.thy ~> src/HOL/
   501     src/HOL/Real/Real.thy ~> src/HOL/
   502     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   503     src/HOL/Complex/Complex.thy ~> src/HOL/
   504     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   505     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   506     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   507     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   508     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   509     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   510     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   511     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   512     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   513     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   514     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   515     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   516     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   517     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   518     src/HOL/Real/Float ~> src/HOL/Library/
   519     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   520     src/HOL/Real/RealVector.thy ~> src/HOL/
   521 
   522     src/HOL/arith_data.ML ~> src/HOL/Tools
   523     src/HOL/hologic.ML ~> src/HOL/Tools
   524     src/HOL/simpdata.ML ~> src/HOL/Tools
   525     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   526     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   527     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   528     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   529     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   530     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   531     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   532 
   533     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   534     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   535     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   536     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   537     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   538     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   539 
   540 * If methods "eval" and "evaluation" encounter a structured proof
   541 state with !!/==>, only the conclusion is evaluated to True (if
   542 possible), avoiding strange error messages.
   543 
   544 * Method "sizechange" automates termination proofs using (a
   545 modification of) the size-change principle.  Requires SAT solver.  See
   546 src/HOL/ex/Termination.thy for examples.
   547 
   548 * Simplifier: simproc for let expressions now unfolds if bound
   549 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   550 
   551 * Method "arith": Linear arithmetic now ignores all inequalities when
   552 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   553 
   554 * New attribute "arith" for facts that should always be used
   555 automatically by arithmetic. It is intended to be used locally in
   556 proofs, e.g.
   557 
   558   assumes [arith]: "x > 0"
   559 
   560 Global usage is discouraged because of possible performance impact.
   561 
   562 * New classes "top" and "bot" with corresponding operations "top" and
   563 "bot" in theory Orderings; instantiation of class "complete_lattice"
   564 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   565 
   566 * Changed definition lemma "less_fun_def" in order to provide an
   567 instance for preorders on functions; use lemma "less_le" instead.
   568 INCOMPATIBILITY.
   569 
   570 * Theory Orderings: class "wellorder" moved here, with explicit
   571 induction rule "less_induct" as assumption.  For instantiation of
   572 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   573 INCOMPATIBILITY.
   574 
   575 * Theory Orderings: added class "preorder" as superclass of "order".
   576 INCOMPATIBILITY: Instantiation proofs for order, linorder
   577 etc. slightly changed.  Some theorems named order_class.* now named
   578 preorder_class.*.
   579 
   580 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   581 "diag" to "Id_on".
   582 
   583 * Theory Finite_Set: added a new fold combinator of type
   584 
   585   ('a => 'b => 'b) => 'b => 'a set => 'b
   586 
   587 Occasionally this is more convenient than the old fold combinator
   588 which is now defined in terms of the new one and renamed to
   589 fold_image.
   590 
   591 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   592 and "ring_simps" have been replaced by "algebra_simps" (which can be
   593 extended with further lemmas!).  At the moment both still exist but
   594 the former will disappear at some point.
   595 
   596 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   597 class recpower.  Type-specific simp rules for various recpower types
   598 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   599 
   600 rat_power_0    -> power_0
   601 rat_power_Suc  -> power_Suc
   602 realpow_0      -> power_0
   603 realpow_Suc    -> power_Suc
   604 complexpow_0   -> power_0
   605 complexpow_Suc -> power_Suc
   606 power_poly_0   -> power_0
   607 power_poly_Suc -> power_Suc
   608 
   609 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   610 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   611 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   612 of lemmas from Divides has been generalized from nat to class
   613 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   614 renames resulting from duplicate elimination:
   615 
   616     dvd_def_mod ~>          dvd_eq_mod_eq_0
   617     zero_dvd_iff ~>         dvd_0_left_iff
   618     dvd_0 ~>                dvd_0_right
   619     DIVISION_BY_ZERO_DIV ~> div_by_0
   620     DIVISION_BY_ZERO_MOD ~> mod_by_0
   621     mult_div ~>             div_mult_self2_is_id
   622     mult_mod ~>             mod_mult_self2_is_0
   623 
   624 * Theory IntDiv: removed many lemmas that are instances of class-based
   625 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   626 rename old lemmas as follows:
   627 
   628 dvd_diff               -> nat_dvd_diff
   629 dvd_zminus_iff         -> dvd_minus_iff
   630 mod_add1_eq            -> mod_add_eq
   631 mod_mult1_eq           -> mod_mult_right_eq
   632 mod_mult1_eq'          -> mod_mult_left_eq
   633 mod_mult_distrib_mod   -> mod_mult_eq
   634 nat_mod_add_left_eq    -> mod_add_left_eq
   635 nat_mod_add_right_eq   -> mod_add_right_eq
   636 nat_mod_div_trivial    -> mod_div_trivial
   637 nat_mod_mod_trivial    -> mod_mod_trivial
   638 zdiv_zadd_self1        -> div_add_self1
   639 zdiv_zadd_self2        -> div_add_self2
   640 zdiv_zmult_self1       -> div_mult_self2_is_id
   641 zdiv_zmult_self2       -> div_mult_self1_is_id
   642 zdvd_triv_left         -> dvd_triv_left
   643 zdvd_triv_right        -> dvd_triv_right
   644 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   645 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   646 zmod_zadd_left_eq      -> mod_add_left_eq
   647 zmod_zadd_right_eq     -> mod_add_right_eq
   648 zmod_zadd_self1        -> mod_add_self1
   649 zmod_zadd_self2        -> mod_add_self2
   650 zmod_zadd1_eq          -> mod_add_eq
   651 zmod_zdiff1_eq         -> mod_diff_eq
   652 zmod_zdvd_zmod         -> mod_mod_cancel
   653 zmod_zmod_cancel       -> mod_mod_cancel
   654 zmod_zmult_self1       -> mod_mult_self2_is_0
   655 zmod_zmult_self2       -> mod_mult_self1_is_0
   656 zmod_1                 -> mod_by_1
   657 zdiv_1                 -> div_by_1
   658 zdvd_abs1              -> abs_dvd_iff
   659 zdvd_abs2              -> dvd_abs_iff
   660 zdvd_refl              -> dvd_refl
   661 zdvd_trans             -> dvd_trans
   662 zdvd_zadd              -> dvd_add
   663 zdvd_zdiff             -> dvd_diff
   664 zdvd_zminus_iff        -> dvd_minus_iff
   665 zdvd_zminus2_iff       -> minus_dvd_iff
   666 zdvd_zmultD            -> dvd_mult_right
   667 zdvd_zmultD2           -> dvd_mult_left
   668 zdvd_zmult_mono        -> mult_dvd_mono
   669 zdvd_0_right           -> dvd_0_right
   670 zdvd_0_left            -> dvd_0_left_iff
   671 zdvd_1_left            -> one_dvd
   672 zminus_dvd_iff         -> minus_dvd_iff
   673 
   674 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   675 
   676 * The real numbers offer decimal input syntax: 12.34 is translated
   677 into 1234/10^2. This translation is not reversed upon output.
   678 
   679 * Theory Library/Polynomial defines an abstract type 'a poly of
   680 univariate polynomials with coefficients of type 'a.  In addition to
   681 the standard ring operations, it also supports div and mod.  Code
   682 generation is also supported, using list-style constructors.
   683 
   684 * Theory Library/Inner_Product defines a class of real_inner for real
   685 inner product spaces, with an overloaded operation inner :: 'a => 'a
   686 => real.  Class real_inner is a subclass of real_normed_vector from
   687 theory RealVector.
   688 
   689 * Theory Library/Product_Vector provides instances for the product
   690 type 'a * 'b of several classes from RealVector and Inner_Product.
   691 Definitions of addition, subtraction, scalar multiplication, norms,
   692 and inner products are included.
   693 
   694 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   695 addition to the field operations, numerals and case syntax are also
   696 supported.
   697 
   698 * Theory Library/Diagonalize provides constructive version of Cantor's
   699 first diagonalization argument.
   700 
   701 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   702 zlcm (for int); carried together from various gcd/lcm developements in
   703 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   704 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   705 may recover tupled syntax as follows:
   706 
   707     hide (open) const gcd
   708     abbreviation gcd where
   709       "gcd == (%(a, b). GCD.gcd a b)"
   710     notation (output)
   711       GCD.gcd ("gcd '(_, _')")
   712 
   713 The same works for lcm, zgcd, zlcm.
   714 
   715 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   716 instantiations for algebraic structures.  Removed some duplicate
   717 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   718 
   719 * ML antiquotation @{code} takes a constant as argument and generates
   720 corresponding code in background and inserts name of the corresponding
   721 resulting ML value/function/datatype constructor binding in place.
   722 All occurrences of @{code} with a single ML block are generated
   723 simultaneously.  Provides a generic and safe interface for
   724 instrumentalizing code generation.  See
   725 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   726 In future you ought to refrain from ad-hoc compiling generated SML
   727 code on the ML toplevel.  Note that (for technical reasons) @{code}
   728 cannot refer to constants for which user-defined serializations are
   729 set.  Refer to the corresponding ML counterpart directly in that
   730 cases.
   731 
   732 * Command 'rep_datatype': instead of theorem names the command now
   733 takes a list of terms denoting the constructors of the type to be
   734 represented as datatype.  The characteristic theorems have to be
   735 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   736 have disappeared in favour of existing ones:
   737 
   738     unit_induct                 ~> unit.induct
   739     prod_induct                 ~> prod.induct
   740     sum_induct                  ~> sum.induct
   741     Suc_Suc_eq                  ~> nat.inject
   742     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   743 
   744 
   745 *** HOL-Algebra ***
   746 
   747 * New locales for orders and lattices where the equivalence relation
   748 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   749 locales use a record structure with field eq for the equivalence.
   750 
   751 * New theory of factorial domains.
   752 
   753 * Units_l_inv and Units_r_inv are now simp rules by default.
   754 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   755 and/or r_inv will now also require deletion of these lemmas.
   756 
   757 * Renamed the following theorems, INCOMPATIBILITY:
   758 
   759 UpperD ~> Upper_memD
   760 LowerD ~> Lower_memD
   761 least_carrier ~> least_closed
   762 greatest_carrier ~> greatest_closed
   763 greatest_Lower_above ~> greatest_Lower_below
   764 one_zero ~> carrier_one_zero
   765 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   766 
   767 
   768 *** HOL-Nominal ***
   769 
   770 * Nominal datatypes can now contain type-variables.
   771 
   772 * Commands 'nominal_inductive' and 'equivariance' work with local
   773 theory targets.
   774 
   775 * Nominal primrec can now works with local theory targets and its
   776 specification syntax now conforms to the general format as seen in
   777 'inductive' etc.
   778 
   779 * Method "perm_simp" honours the standard simplifier attributes
   780 (no_asm), (no_asm_use) etc.
   781 
   782 * The new predicate #* is defined like freshness, except that on the
   783 left hand side can be a set or list of atoms.
   784 
   785 * Experimental command 'nominal_inductive2' derives strong induction
   786 principles for inductive definitions.  In contrast to
   787 'nominal_inductive', which can only deal with a fixed number of
   788 binders, it can deal with arbitrary expressions standing for sets of
   789 atoms to be avoided.  The only inductive definition we have at the
   790 moment that needs this generalisation is the typing rule for Lets in
   791 the algorithm W:
   792 
   793  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   794  -----------------------------------------------------------------
   795          Gamma |- Let x be t1 in t2 : T2
   796 
   797 In this rule one wants to avoid all the binders that are introduced by
   798 "close Gamma T1".  We are looking for other examples where this
   799 feature might be useful.  Please let us know.
   800 
   801 
   802 *** HOLCF ***
   803 
   804 * Reimplemented the simplification procedure for proving continuity
   805 subgoals.  The new simproc is extensible; users can declare additional
   806 continuity introduction rules with the attribute [cont2cont].
   807 
   808 * The continuity simproc now uses a different introduction rule for
   809 solving continuity subgoals on terms with lambda abstractions.  In
   810 some rare cases the new simproc may fail to solve subgoals that the
   811 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   812 Potential INCOMPATIBILITY.
   813 
   814 * Command 'fixrec': specification syntax now conforms to the general
   815 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   816 examples.  INCOMPATIBILITY.
   817 
   818 
   819 *** ZF ***
   820 
   821 * Proof of Zorn's Lemma for partial orders.
   822 
   823 
   824 *** ML ***
   825 
   826 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   827 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   828 depends on multithreading, so timouts will not work before Poly/ML
   829 5.2.1!
   830 
   831 * High-level support for concurrent ML programming, see
   832 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   833 particularly convenient to organize independent functional
   834 computations.  The concept of "synchronized variables" provides a
   835 higher-order interface for components with shared state, avoiding the
   836 delicate details of mutexes and condition variables.  (Requires
   837 Poly/ML 5.2.1 or later.)
   838 
   839 * ML bindings produced via Isar commands are stored within the Isar
   840 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   841 become thread-safe and work with undo as expected (concerning
   842 top-level bindings, not side-effects on global references).
   843 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   844 compiler at runtime; really global bindings need to be given outside a
   845 theory.  (Requires Poly/ML 5.2 or later.)
   846 
   847 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   848 context.  Top-level ML bindings are stored within the proof context in
   849 a purely sequential fashion, disregarding the nested proof structure.
   850 ML bindings introduced by 'ML_prf' are discarded at the end of the
   851 proof.  (Requires Poly/ML 5.2 or later.)
   852 
   853 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   854 and Method.setup, as well as Isar commands 'attribute_setup' and
   855 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   856 existing code accordingly, or use plain 'setup' together with old
   857 Method.add_method.
   858 
   859 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   860 to 'a -> thm, while results are always tagged with an authentic oracle
   861 name.  The Isar command 'oracle' is now polymorphic, no argument type
   862 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   863 accordingly.  Note that extra performance may be gained by producing
   864 the cterm carefully, avoiding slow Thm.cterm_of.
   865 
   866 * Simplified interface for defining document antiquotations via
   867 ThyOutput.antiquotation, ThyOutput.output, and optionally
   868 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   869 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   870 examples.
   871 
   872 * More systematic treatment of long names, abstract name bindings, and
   873 name space operations.  Basic operations on qualified names have been
   874 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   875 Long_Name.append.  Old type bstring has been mostly replaced by
   876 abstract type binding (see structure Binding), which supports precise
   877 qualification by packages and local theory targets, as well as proper
   878 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   879 bstring values into Binding.name, or better pass through abstract
   880 bindings everywhere.  See further src/Pure/General/long_name.ML,
   881 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   882 
   883 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   884 LocalTheory.note etc.) now refer to the *full* internal name, not the
   885 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   886 
   887 * Disposed old type and term read functions (Sign.read_def_typ,
   888 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   889 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   890 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   891 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   892 resort for legacy applications.
   893 
   894 * Disposed old declarations, tactics, tactic combinators that refer to
   895 the simpset or claset of an implicit theory (such as Addsimps,
   896 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   897 embedded ML text, or local_simpset_of with a proper context passed as
   898 explicit runtime argument.
   899 
   900 * Rules and tactics that read instantiations (read_instantiate,
   901 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   902 context, which is required for parsing and type-checking.  Moreover,
   903 the variables are specified as plain indexnames, not string encodings
   904 thereof.  INCOMPATIBILITY.
   905 
   906 * Generic Toplevel.add_hook interface allows to analyze the result of
   907 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   908 for theorem dependency output of transactions resulting in a new
   909 theory state.
   910 
   911 * ML antiquotations: block-structured compilation context indicated by
   912 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   913 
   914   @{binding name}                         - basic name binding
   915   @{let ?pat = term}                      - term abbreviation (HO matching)
   916   @{note name = fact}                     - fact abbreviation
   917   @{thm fact}                             - singleton fact (with attributes)
   918   @{thms fact}                            - general fact (with attributes)
   919   @{lemma prop by method}                 - singleton goal
   920   @{lemma prop by meth1 meth2}            - singleton goal
   921   @{lemma prop1 ... propN by method}      - general goal
   922   @{lemma prop1 ... propN by meth1 meth2} - general goal
   923   @{lemma (open) ...}                     - open derivation
   924 
   925 
   926 *** System ***
   927 
   928 * The Isabelle "emacs" tool provides a specific interface to invoke
   929 Proof General / Emacs, with more explicit failure if that is not
   930 installed (the old isabelle-interface script silently falls back on
   931 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   932 installation location of the Proof General distribution.
   933 
   934 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   935 the Isabelle process into a JVM/Scala application.  See
   936 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   937 process wrapper has been discontinued.)
   938 
   939 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   940 
   941 * Various status messages (with exact source position information) are
   942 emitted, if proper markup print mode is enabled.  This allows
   943 user-interface components to provide detailed feedback on internal
   944 prover operations.
   945 
   946 
   947 
   948 New in Isabelle2008 (June 2008)
   949 -------------------------------
   950 
   951 *** General ***
   952 
   953 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   954 and updated, with formally checked references as hyperlinks.
   955 
   956 * Theory loader: use_thy (and similar operations) no longer set the
   957 implicit ML context, which was occasionally hard to predict and in
   958 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   959 provides a proper context already.
   960 
   961 * Theory loader: old-style ML proof scripts being *attached* to a thy
   962 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   963 'use' within a theory file will do the job.
   964 
   965 * Name space merge now observes canonical order, i.e. the second space
   966 is inserted into the first one, while existing entries in the first
   967 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   968 swap theory imports.
   969 
   970 * Syntax: symbol \<chi> is now considered a letter.  Potential
   971 INCOMPATIBILITY in identifier syntax etc.
   972 
   973 * Outer syntax: string tokens no longer admit escaped white space,
   974 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   975 white space without escapes.
   976 
   977 * Outer syntax: string tokens may contain arbitrary character codes
   978 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   979 "foo_bar".
   980 
   981 
   982 *** Pure ***
   983 
   984 * Context-dependent token translations.  Default setup reverts locally
   985 fixed variables, and adds hilite markup for undeclared frees.
   986 
   987 * Unused theorems can be found using the new command 'unused_thms'.
   988 There are three ways of invoking it:
   989 
   990 (1) unused_thms
   991      Only finds unused theorems in the current theory.
   992 
   993 (2) unused_thms thy_1 ... thy_n -
   994      Finds unused theorems in the current theory and all of its ancestors,
   995      excluding the theories thy_1 ... thy_n and all of their ancestors.
   996 
   997 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   998      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   999      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1000      their ancestors.
  1001 
  1002 In order to increase the readability of the list produced by
  1003 unused_thms, theorems that have been created by a particular instance
  1004 of a theory command such as 'inductive' or 'function' are considered
  1005 to belong to the same "group", meaning that if at least one theorem in
  1006 this group is used, the other theorems in the same group are no longer
  1007 reported as unused.  Moreover, if all theorems in the group are
  1008 unused, only one theorem in the group is displayed.
  1009 
  1010 Note that proof objects have to be switched on in order for
  1011 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1012 usually the case when using Proof General with the default settings).
  1013 
  1014 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1015 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1016 duplicate fact bindings, or even accidental fact duplications.  Note
  1017 that tools may maintain dynamically scoped facts systematically, using
  1018 PureThy.add_thms_dynamic.
  1019 
  1020 * Command 'hide' now allows to hide from "fact" name space as well.
  1021 
  1022 * Eliminated destructive theorem database, simpset, claset, and
  1023 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1024 update of theories within ML code.
  1025 
  1026 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1027 INCOMPATIBILITY, object-logics depending on former Pure require
  1028 additional setup PureThy.old_appl_syntax_setup; object-logics
  1029 depending on former CPure need to refer to Pure.
  1030 
  1031 * Commands 'use' and 'ML' are now purely functional, operating on
  1032 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1033 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1034 INCOMPATIBILITY.
  1035 
  1036 * Command 'setup': discontinued implicit version with ML reference.
  1037 
  1038 * Instantiation target allows for simultaneous specification of class
  1039 instance operations together with an instantiation proof.
  1040 Type-checking phase allows to refer to class operations uniformly.
  1041 See src/HOL/Complex/Complex.thy for an Isar example and
  1042 src/HOL/Library/Eval.thy for an ML example.
  1043 
  1044 * Indexing of literal facts: be more serious about including only
  1045 facts from the visible specification/proof context, but not the
  1046 background context (locale etc.).  Affects `prop` notation and method
  1047 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1048 situations.
  1049 
  1050 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1051 "(open)" option, which used to expose internal bound variables to the
  1052 proof text.
  1053 
  1054 * Isar statements: removed obsolete case "rule_context".
  1055 INCOMPATIBILITY, better use explicit fixes/assumes.
  1056 
  1057 * Locale proofs: default proof step now includes 'unfold_locales';
  1058 hence 'proof' without argument may be used to unfold locale
  1059 predicates.
  1060 
  1061 
  1062 *** Document preparation ***
  1063 
  1064 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1065 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1066 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1067 spot); renamed link color from "darkblue" to "linkcolor" (default
  1068 value unchanged, can be redefined via \definecolor); no longer sets
  1069 "a4paper" option (unnecessary or even intrusive).
  1070 
  1071 * Antiquotation @{lemma A method} proves proposition A by the given
  1072 method (either a method name or a method name plus (optional) method
  1073 arguments in parentheses) and prints A just like @{prop A}.
  1074 
  1075 
  1076 *** HOL ***
  1077 
  1078 * New primrec package.  Specification syntax conforms in style to
  1079 definition/function/....  No separate induction rule is provided.  The
  1080 "primrec" command distinguishes old-style and new-style specifications
  1081 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1082 When adjusting theories, beware: constants stemming from new-style
  1083 primrec specifications have authentic syntax.
  1084 
  1085 * Metis prover is now an order of magnitude faster, and also works
  1086 with multithreading.
  1087 
  1088 * Metis: the maximum number of clauses that can be produced from a
  1089 theorem is now given by the attribute max_clauses.  Theorems that
  1090 exceed this number are ignored, with a warning printed.
  1091 
  1092 * Sledgehammer no longer produces structured proofs by default. To
  1093 enable, declare [[sledgehammer_full = true]].  Attributes
  1094 reconstruction_modulus, reconstruction_sorts renamed
  1095 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1096 
  1097 * Method "induct_scheme" derives user-specified induction rules
  1098 from well-founded induction and completeness of patterns. This factors
  1099 out some operations that are done internally by the function package
  1100 and makes them available separately.  See
  1101 src/HOL/ex/Induction_Scheme.thy for examples.
  1102 
  1103 * More flexible generation of measure functions for termination
  1104 proofs: Measure functions can be declared by proving a rule of the
  1105 form "is_measure f" and giving it the [measure_function] attribute.
  1106 The "is_measure" predicate is logically meaningless (always true), and
  1107 just guides the heuristic.  To find suitable measure functions, the
  1108 termination prover sets up the goal "is_measure ?f" of the appropriate
  1109 type and generates all solutions by prolog-style backwards proof using
  1110 the declared rules.
  1111 
  1112 This setup also deals with rules like 
  1113 
  1114   "is_measure f ==> is_measure (list_size f)"
  1115 
  1116 which accommodates nested datatypes that recurse through lists.
  1117 Similar rules are predeclared for products and option types.
  1118 
  1119 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1120 
  1121   INCOMPATIBILITIES:
  1122 
  1123   - Definitions of overloaded constants on sets have to be replaced by
  1124     definitions on => and bool.
  1125 
  1126   - Some definitions of overloaded operators on sets can now be proved
  1127     using the definitions of the operators on => and bool.  Therefore,
  1128     the following theorems have been renamed:
  1129 
  1130       subset_def   -> subset_eq
  1131       psubset_def  -> psubset_eq
  1132       set_diff_def -> set_diff_eq
  1133       Compl_def    -> Compl_eq
  1134       Sup_set_def  -> Sup_set_eq
  1135       Inf_set_def  -> Inf_set_eq
  1136       sup_set_def  -> sup_set_eq
  1137       inf_set_def  -> inf_set_eq
  1138 
  1139   - Due to the incompleteness of the HO unification algorithm, some
  1140     rules such as subst may require manual instantiation, if some of
  1141     the unknowns in the rule is a set.
  1142 
  1143   - Higher order unification and forward proofs:
  1144     The proof pattern
  1145 
  1146       have "P (S::'a set)" <...>
  1147       then have "EX S. P S" ..
  1148 
  1149     no longer works (due to the incompleteness of the HO unification
  1150     algorithm) and must be replaced by the pattern
  1151 
  1152       have "EX S. P S"
  1153       proof
  1154         show "P S" <...>
  1155       qed
  1156 
  1157   - Calculational reasoning with subst (or similar rules):
  1158     The proof pattern
  1159 
  1160       have "P (S::'a set)" <...>
  1161       also have "S = T" <...>
  1162       finally have "P T" .
  1163 
  1164     no longer works (for similar reasons as the previous example) and
  1165     must be replaced by something like
  1166 
  1167       have "P (S::'a set)" <...>
  1168       moreover have "S = T" <...>
  1169       ultimately have "P T" by simp
  1170 
  1171   - Tactics or packages written in ML code:
  1172     Code performing pattern matching on types via
  1173 
  1174       Type ("set", [T]) => ...
  1175 
  1176     must be rewritten. Moreover, functions like strip_type or
  1177     binder_types no longer return the right value when applied to a
  1178     type of the form
  1179 
  1180       T1 => ... => Tn => U => bool
  1181 
  1182     rather than
  1183 
  1184       T1 => ... => Tn => U set
  1185 
  1186 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1187 Wellfounded_Relations to theory Wellfounded.
  1188 
  1189 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1190 
  1191 * Class finite no longer treats UNIV as class parameter.  Use class
  1192 enum from theory Library/Enum instead to achieve a similar effect.
  1193 INCOMPATIBILITY.
  1194 
  1195 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1196 and "Cons".  INCOMPATIBILITY.
  1197 
  1198 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1199 Potential INCOMPATIBILITY.
  1200 
  1201 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1202 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1203 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1204 
  1205 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1206 the same name in theory Orderings:
  1207 
  1208   less_trans
  1209   less_linear
  1210   le_imp_less_or_eq
  1211   le_less_trans
  1212   less_le_trans
  1213   less_not_sym
  1214   less_asym
  1215 
  1216 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1217 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1218 and different variable names.
  1219 
  1220 * Library/Option_ord.thy: Canonical order on option type.
  1221 
  1222 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1223 finite maps.
  1224 
  1225 * Library/Countable.thy: Type class for countable types.
  1226 
  1227 * Theory Int: The representation of numerals has changed.  The infix
  1228 operator BIT and the bit datatype with constructors B0 and B1 have
  1229 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1230 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1231 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1232 accordingly.
  1233 
  1234 * Theory Nat: definition of <= and < on natural numbers no longer
  1235 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1236 le_def and less_def have disappeared.  Consider lemmas not_less
  1237 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1238 
  1239 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1240 (whose purpose mainly is for various fold_set functionals) have been
  1241 abandoned in favor of the existing algebraic classes
  1242 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1243 lower_semilattice (resp. upper_semilattice) and linorder.
  1244 INCOMPATIBILITY.
  1245 
  1246 * Theory Transitive_Closure: induct and cases rules now declare proper
  1247 case_names ("base" and "step").  INCOMPATIBILITY.
  1248 
  1249 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1250 lattices.  The form set-specific version is available as
  1251 Inductive.lfp_ordinal_induct_set.
  1252 
  1253 * Renamed theorems "power.simps" to "power_int.simps".
  1254 INCOMPATIBILITY.
  1255 
  1256 * Class semiring_div provides basic abstract properties of semirings
  1257 with division and modulo operations.  Subsumes former class dvd_mod.
  1258 
  1259 * Merged theories IntDef, Numeral and IntArith into unified theory
  1260 Int.  INCOMPATIBILITY.
  1261 
  1262 * Theory Library/Code_Index: type "index" now represents natural
  1263 numbers rather than integers.  INCOMPATIBILITY.
  1264 
  1265 * New class "uminus" with operation "uminus" (split of from class
  1266 "minus" which now only has operation "minus", binary).
  1267 INCOMPATIBILITY.
  1268 
  1269 * Constants "card", "internal_split", "option_map" now with authentic
  1270 syntax.  INCOMPATIBILITY.
  1271 
  1272 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1273 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1274 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1275 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1276 Sup_set_def, le_def, less_def, option_map_def now with object
  1277 equality.  INCOMPATIBILITY.
  1278 
  1279 * Records. Removed K_record, and replaced it by pure lambda term
  1280 %x. c. The simplifier setup is now more robust against eta expansion.
  1281 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1282 
  1283 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1284 
  1285 * Library/ListVector: new theory of arithmetic vector operations.
  1286 
  1287 * Library/Order_Relation: new theory of various orderings as sets of
  1288 pairs.  Defines preorders, partial orders, linear orders and
  1289 well-orders on sets and on types.
  1290 
  1291 
  1292 *** ZF ***
  1293 
  1294 * Renamed some theories to allow to loading both ZF and HOL in the
  1295 same session:
  1296 
  1297   Datatype  -> Datatype_ZF
  1298   Inductive -> Inductive_ZF
  1299   Int       -> Int_ZF
  1300   IntDiv    -> IntDiv_ZF
  1301   Nat       -> Nat_ZF
  1302   List      -> List_ZF
  1303   Main      -> Main_ZF
  1304 
  1305 INCOMPATIBILITY: ZF theories that import individual theories below
  1306 Main might need to be adapted.  Regular theory Main is still
  1307 available, as trivial extension of Main_ZF.
  1308 
  1309 
  1310 *** ML ***
  1311 
  1312 * ML within Isar: antiquotation @{const name} or @{const
  1313 name(typargs)} produces statically-checked Const term.
  1314 
  1315 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1316 (of the same name).  Removed obsolete print command.
  1317 
  1318 * Removed obsolete "use_legacy_bindings" function.
  1319 
  1320 * The ``print mode'' is now a thread-local value derived from a global
  1321 template (the former print_mode reference), thus access becomes
  1322 non-critical.  The global print_mode reference is for session
  1323 management only; user-code should use print_mode_value,
  1324 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1325 
  1326 * Functions system/system_out provide a robust way to invoke external
  1327 shell commands, with propagation of interrupts (requires Poly/ML
  1328 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1329 
  1330 
  1331 *** System ***
  1332 
  1333 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1334 in accordance with Proof General 3.7, which prefers GNU emacs.
  1335 
  1336 * isatool tty runs Isabelle process with plain tty interaction;
  1337 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1338 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1339 
  1340 * isatool browser now works with Cygwin as well, using general
  1341 "javapath" function defined in Isabelle process environment.
  1342 
  1343 * YXML notation provides a simple and efficient alternative to
  1344 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1345 isatool yxml as described in the Isabelle system manual.
  1346 
  1347 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1348 provides general wrapper for managing an Isabelle process in a robust
  1349 fashion, with ``cooked'' output from stdin/stderr.
  1350 
  1351 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1352 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1353 
  1354 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1355 way of changing the user's settings is via
  1356 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1357 script.
  1358 
  1359 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1360 cores of the underlying machine, which is a good starting point for
  1361 optimal performance tuning.  The corresponding usedir option -M allows
  1362 "max" as an alias for "0".  WARNING: does not work on certain versions
  1363 of Mac OS (with Poly/ML 5.1).
  1364 
  1365 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1366 adverse effect of Isabelle flooding interactive front-ends (notably
  1367 ProofGeneral / XEmacs).
  1368 
  1369 
  1370 
  1371 New in Isabelle2007 (November 2007)
  1372 -----------------------------------
  1373 
  1374 *** General ***
  1375 
  1376 * More uniform information about legacy features, notably a
  1377 warning/error of "Legacy feature: ...", depending on the state of the
  1378 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1379 legacy features will disappear eventually.
  1380 
  1381 * Theory syntax: the header format ``theory A = B + C:'' has been
  1382 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1383 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1384 
  1385 * Theory syntax: the old non-Isar theory file format has been
  1386 discontinued altogether.  Note that ML proof scripts may still be used
  1387 with Isar theories; migration is usually quite simple with the ML
  1388 function use_legacy_bindings.  INCOMPATIBILITY.
  1389 
  1390 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1391 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1392 quotes.
  1393 
  1394 * Theory loader: be more serious about observing the static theory
  1395 header specifications (including optional directories), but not the
  1396 accidental file locations of previously successful loads.  The strict
  1397 update policy of former update_thy is now already performed by
  1398 use_thy, so the former has been removed; use_thys updates several
  1399 theories simultaneously, just as 'imports' within a theory header
  1400 specification, but without merging the results.  Potential
  1401 INCOMPATIBILITY: may need to refine theory headers and commands
  1402 ROOT.ML which depend on load order.
  1403 
  1404 * Theory loader: optional support for content-based file
  1405 identification, instead of the traditional scheme of full physical
  1406 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1407 (cf. the system manual).  The new scheme allows to work with
  1408 non-finished theories in persistent session images, such that source
  1409 files may be moved later on without requiring reloads.
  1410 
  1411 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1412 file (with the same base name as the theory) are considered a legacy
  1413 feature, which will disappear eventually. Even now, the theory loader
  1414 no longer maintains dependencies on such files.
  1415 
  1416 * Syntax: the scope for resolving ambiguities via type-inference is
  1417 now limited to individual terms, instead of whole simultaneous
  1418 specifications as before. This greatly reduces the complexity of the
  1419 syntax module and improves flexibility by separating parsing and
  1420 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1421 'fixes' etc.) are required in rare situations.
  1422 
  1423 * Syntax: constants introduced by new-style packages ('definition',
  1424 'abbreviation' etc.) are passed through the syntax module in
  1425 ``authentic mode''. This means that associated mixfix annotations
  1426 really stick to such constants, independently of potential name space
  1427 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1428 trees are represented slightly differently, may need to adapt syntax
  1429 translations accordingly. Use CONST marker in 'translations' and
  1430 @{const_syntax} antiquotation in 'parse_translation' etc.
  1431 
  1432 * Legacy goal package: reduced interface to the bare minimum required
  1433 to keep existing proof scripts running.  Most other user-level
  1434 functions are now part of the OldGoals structure, which is *not* open
  1435 by default (consider isatool expandshort before open OldGoals).
  1436 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1437 these tend to cause confusion about the actual goal (!) context being
  1438 used here, which is not necessarily the same as the_context().
  1439 
  1440 * Command 'find_theorems': supports "*" wild-card in "name:"
  1441 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1442 support a specific search form (see ProofGeneral/CHANGES).
  1443 
  1444 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1445 by default, which means that "prems" (and also "fixed variables") are
  1446 suppressed from proof state output.  Note that the ProofGeneral
  1447 settings mechanism allows to change and save options persistently, but
  1448 older versions of Isabelle will fail to start up if a negative prems
  1449 limit is imposed.
  1450 
  1451 * Local theory targets may be specified by non-nested blocks of
  1452 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1453 contain definitions, theorems etc., including any derived mechanism
  1454 that has been implemented on top of these primitives.  This concept
  1455 generalizes the existing ``theorem (in ...)'' towards more versatility
  1456 and scalability.
  1457 
  1458 * Proof General interface: proper undo of final 'end' command;
  1459 discontinued Isabelle/classic mode (ML proof scripts).
  1460 
  1461 
  1462 *** Document preparation ***
  1463 
  1464 * Added antiquotation @{theory name} which prints the given name,
  1465 after checking that it refers to a valid ancestor theory in the
  1466 current context.
  1467 
  1468 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1469 check the given source text as ML type/structure, printing verbatim.
  1470 
  1471 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1472 "c args == rhs" given in the current context.  (Any number of
  1473 arguments may be given on the LHS.)
  1474 
  1475 
  1476 *** Pure ***
  1477 
  1478 * The 'class' package offers a combination of axclass and locale to
  1479 achieve Haskell-like type classes in Isabelle.  Definitions and
  1480 theorems within a class context produce both relative results (with
  1481 implicit parameters according to the locale context), and polymorphic
  1482 constants with qualified polymorphism (according to the class
  1483 context).  Within the body context of a 'class' target, a separate
  1484 syntax layer ("user space type system") takes care of converting
  1485 between global polymorphic consts and internal locale representation.
  1486 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1487 "isatool doc classes" provides a tutorial.
  1488 
  1489 * Generic code generator framework allows to generate executable
  1490 code for ML and Haskell (including Isabelle classes).  A short usage
  1491 sketch:
  1492 
  1493     internal compilation:
  1494         export_code <list of constants (term syntax)> in SML
  1495     writing SML code to a file:
  1496         export_code <list of constants (term syntax)> in SML <filename>
  1497     writing OCaml code to a file:
  1498         export_code <list of constants (term syntax)> in OCaml <filename>
  1499     writing Haskell code to a bunch of files:
  1500         export_code <list of constants (term syntax)> in Haskell <filename>
  1501 
  1502     evaluating closed propositions to True/False using code generation:
  1503         method ``eval''
  1504 
  1505 Reasonable default setup of framework in HOL.
  1506 
  1507 Theorem attributs for selecting and transforming function equations theorems:
  1508 
  1509     [code fun]:        select a theorem as function equation for a specific constant
  1510     [code fun del]:    deselect a theorem as function equation for a specific constant
  1511     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1512     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1513 
  1514 User-defined serializations (target in {SML, OCaml, Haskell}):
  1515 
  1516     code_const <and-list of constants (term syntax)>
  1517       {(target) <and-list of const target syntax>}+
  1518 
  1519     code_type <and-list of type constructors>
  1520       {(target) <and-list of type target syntax>}+
  1521 
  1522     code_instance <and-list of instances>
  1523       {(target)}+
  1524         where instance ::= <type constructor> :: <class>
  1525 
  1526     code_class <and_list of classes>
  1527       {(target) <and-list of class target syntax>}+
  1528         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1529 
  1530 code_instance and code_class only are effective to target Haskell.
  1531 
  1532 For example usage see src/HOL/ex/Codegenerator.thy and
  1533 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1534 generation from Isabelle/HOL theories is available via "isatool doc
  1535 codegen".
  1536 
  1537 * Code generator: consts in 'consts_code' Isar commands are now
  1538 referred to by usual term syntax (including optional type
  1539 annotations).
  1540 
  1541 * Command 'no_translations' removes translation rules from theory
  1542 syntax.
  1543 
  1544 * Overloaded definitions are now actually checked for acyclic
  1545 dependencies.  The overloading scheme is slightly more general than
  1546 that of Haskell98, although Isabelle does not demand an exact
  1547 correspondence to type class and instance declarations.
  1548 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1549 exotic versions of overloading -- at the discretion of the user!
  1550 
  1551 Polymorphic constants are represented via type arguments, i.e. the
  1552 instantiation that matches an instance against the most general
  1553 declaration given in the signature.  For example, with the declaration
  1554 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1555 as c(nat).  Overloading is essentially simultaneous structural
  1556 recursion over such type arguments.  Incomplete specification patterns
  1557 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1558 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1559 Command 'print_theory' outputs the normalized system of recursive
  1560 equations, see section "definitions".
  1561 
  1562 * Configuration options are maintained within the theory or proof
  1563 context (with name and type bool/int/string), providing a very simple
  1564 interface to a poor-man's version of general context data.  Tools may
  1565 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1566 these values using Config.get etc.  Users may change options via an
  1567 associated attribute of the same name.  This form of context
  1568 declaration works particularly well with commands 'declare' or
  1569 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1570 very easy to avoid global references, which would not observe Isar
  1571 toplevel undo/redo and fail to work with multithreading.
  1572 
  1573 Various global ML references of Pure and HOL have been turned into
  1574 configuration options:
  1575 
  1576   Unify.search_bound		unify_search_bound
  1577   Unify.trace_bound		unify_trace_bound
  1578   Unify.trace_simp		unify_trace_simp
  1579   Unify.trace_types		unify_trace_types
  1580   Simplifier.simp_depth_limit	simp_depth_limit
  1581   Blast.depth_limit		blast_depth_limit
  1582   DatatypeProp.dtK		datatype_distinctness_limit
  1583   fast_arith_neq_limit  	fast_arith_neq_limit
  1584   fast_arith_split_limit	fast_arith_split_limit
  1585 
  1586 * Named collections of theorems may be easily installed as context
  1587 data using the functor NamedThmsFun (see also
  1588 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1589 attributes; there is also a toplevel print command.  This facility is
  1590 just a common case of general context data, which is the preferred way
  1591 for anything more complex than just a list of facts in canonical
  1592 order.
  1593 
  1594 * Isar: command 'declaration' augments a local theory by generic
  1595 declaration functions written in ML.  This enables arbitrary content
  1596 being added to the context, depending on a morphism that tells the
  1597 difference of the original declaration context wrt. the application
  1598 context encountered later on.
  1599 
  1600 * Isar: proper interfaces for simplification procedures.  Command
  1601 'simproc_setup' declares named simprocs (with match patterns, and body
  1602 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1603 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1604 
  1605 * Isar: an extra pair of brackets around attribute declarations
  1606 abbreviates a theorem reference involving an internal dummy fact,
  1607 which will be ignored later --- only the effect of the attribute on
  1608 the background context will persist.  This form of in-place
  1609 declarations is particularly useful with commands like 'declare' and
  1610 'using', for example ``have A using [[simproc a]] by simp''.
  1611 
  1612 * Isar: method "assumption" (and implicit closing of subproofs) now
  1613 takes simple non-atomic goal assumptions into account: after applying
  1614 an assumption as a rule the resulting subgoals are solved by atomic
  1615 assumption steps.  This is particularly useful to finish 'obtain'
  1616 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1617 without referring to the original premise "!!x. P x ==> thesis" in the
  1618 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1619 more permissive.
  1620 
  1621 * Isar: implicit use of prems from the Isar proof context is
  1622 considered a legacy feature.  Common applications like ``have A .''
  1623 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1624 referencing facts explicitly here improves readability and
  1625 maintainability of proof texts.
  1626 
  1627 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1628 the obtained context from the course of reasoning!  For example:
  1629 
  1630   assume "EX x y. A x & B y"   -- "any previous fact"
  1631   then guess x and y by clarify
  1632 
  1633 This technique is potentially adventurous, depending on the facts and
  1634 proof tools being involved here.
  1635 
  1636 * Isar: known facts from the proof context may be specified as literal
  1637 propositions, using ASCII back-quote syntax.  This works wherever
  1638 named facts used to be allowed so far, in proof commands, proof
  1639 methods, attributes etc.  Literal facts are retrieved from the context
  1640 according to unification of type and term parameters.  For example,
  1641 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1642 theorems in the current context, then these are valid literal facts:
  1643 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1644 
  1645 There is also a proof method "fact" which does the same composition
  1646 for explicit goal states, e.g. the following proof texts coincide with
  1647 certain special cases of literal facts:
  1648 
  1649   have "A" by fact                 ==  note `A`
  1650   have "A ==> B" by fact           ==  note `A ==> B`
  1651   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1652   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1653 
  1654 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1655 outer syntax.  Thus symbolic identifiers may be used without
  1656 additional white space in declarations like this: ``assume *: A''.
  1657 
  1658 * Isar: 'print_facts' prints all local facts of the current context,
  1659 both named and unnamed ones.
  1660 
  1661 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1662 
  1663   def x == "t" and y == "u"
  1664 
  1665 * Isar: added command 'unfolding', which is structurally similar to
  1666 'using', but affects both the goal state and facts by unfolding given
  1667 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1668 'unfolded' attribute may be replaced by first-class proof text.
  1669 
  1670 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1671 and command 'unfolding' now all support object-level equalities
  1672 (potentially conditional).  The underlying notion of rewrite rule is
  1673 analogous to the 'rule_format' attribute, but *not* that of the
  1674 Simplifier (which is usually more generous).
  1675 
  1676 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1677 premises of a theorem by n. Useful in conjunction with drule.
  1678 
  1679 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1680 method expression within a sandbox consisting of the first N
  1681 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1682 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1683 simplifies all new goals that emerge from applying rule foo to the
  1684 originally first one.
  1685 
  1686 * Isar: schematic goals are no longer restricted to higher-order
  1687 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1688 expected.
  1689 
  1690 * Isar: the conclusion of a long theorem statement is now either
  1691 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1692 (essentially a disjunction of cases with local parameters and
  1693 assumptions).  The latter allows to express general elimination rules
  1694 adequately; in this notation common elimination rules look like this:
  1695 
  1696   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1697     assumes "EX x. P x"
  1698     obtains x where "P x"
  1699 
  1700   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1701     assumes "A & B"
  1702     obtains A and B
  1703 
  1704   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1705     assumes "A | B"
  1706     obtains
  1707       A
  1708     | B
  1709 
  1710 The subsequent classical rules even refer to the formal "thesis"
  1711 explicitly:
  1712 
  1713   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1714     obtains "~ thesis"
  1715 
  1716   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1717     obtains "thesis ==> something"
  1718 
  1719 The actual proof of an 'obtains' statement is analogous to that of the
  1720 Isar proof element 'obtain', only that there may be several cases.
  1721 Optional case names may be specified in parentheses; these will be
  1722 available both in the present proof and as annotations in the
  1723 resulting rule, for later use with the 'cases' method (cf. attribute
  1724 case_names).
  1725 
  1726 * Isar: the assumptions of a long theorem statement are available as
  1727 "assms" fact in the proof context.  This is more appropriate than the
  1728 (historical) "prems", which refers to all assumptions of the current
  1729 context, including those from the target locale, proof body etc.
  1730 
  1731 * Isar: 'print_statement' prints theorems from the current theory or
  1732 proof context in long statement form, according to the syntax of a
  1733 top-level lemma.
  1734 
  1735 * Isar: 'obtain' takes an optional case name for the local context
  1736 introduction rule (default "that").
  1737 
  1738 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1739 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1740 to occur.
  1741 
  1742 * Pure: syntax "CONST name" produces a fully internalized constant
  1743 according to the current context.  This is particularly useful for
  1744 syntax translations that should refer to internal constant
  1745 representations independently of name spaces.
  1746 
  1747 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1748 instead of "FOO ". This allows multiple binder declarations to coexist
  1749 in the same context.  INCOMPATIBILITY.
  1750 
  1751 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1752 primitive that also works in a locale context (both for constants and
  1753 fixed variables). Type declaration and internal syntactic representation
  1754 of given constants retrieved from the context. Likewise, the
  1755 'no_notation' command allows to remove given syntax annotations from the
  1756 current context.
  1757 
  1758 * Isar/locales: new derived specification elements 'axiomatization',
  1759 'definition', 'abbreviation', which support type-inference, admit
  1760 object-level specifications (equality, equivalence).  See also the
  1761 isar-ref manual.  Examples:
  1762 
  1763   axiomatization
  1764     eq  (infix "===" 50) where
  1765     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1766 
  1767   definition "f x y = x + y + 1"
  1768   definition g where "g x = f x x"
  1769 
  1770   abbreviation
  1771     neq  (infix "=!=" 50) where
  1772     "x =!= y == ~ (x === y)"
  1773 
  1774 These specifications may be also used in a locale context.  Then the
  1775 constants being introduced depend on certain fixed parameters, and the
  1776 constant name is qualified by the locale base name.  An internal
  1777 abbreviation takes care for convenient input and output, making the
  1778 parameters implicit and using the original short name.  See also
  1779 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1780 entities from a monomorphic theory.
  1781 
  1782 Presently, abbreviations are only available 'in' a target locale, but
  1783 not inherited by general import expressions.  Also note that
  1784 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1785 'translations' in common applications.  The "no_abbrevs" print mode
  1786 prevents folding of abbreviations in term output.
  1787 
  1788 Concrete syntax is attached to specified constants in internal form,
  1789 independently of name spaces.  The parse tree representation is
  1790 slightly different -- use 'notation' instead of raw 'syntax', and
  1791 'translations' with explicit "CONST" markup to accommodate this.
  1792 
  1793 * Pure/Isar: unified syntax for new-style specification mechanisms
  1794 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1795 full type inference and dummy patterns ("_").  For example:
  1796 
  1797   definition "K x _ = x"
  1798 
  1799   inductive conj for A B
  1800   where "A ==> B ==> conj A B"
  1801 
  1802 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1803 the current context.  Print mode "no_abbrevs" prevents inversion of
  1804 abbreviations on output.
  1805 
  1806 * Isar/locales: improved parameter handling: use of locales "var" and
  1807 "struct" no longer necessary; - parameter renamings are no longer
  1808 required to be injective.  For example, this allows to define
  1809 endomorphisms as locale endom = homom mult mult h.
  1810 
  1811 * Isar/locales: changed the way locales with predicates are defined.
  1812 Instead of accumulating the specification, the imported expression is
  1813 now an interpretation.  INCOMPATIBILITY: different normal form of
  1814 locale expressions.  In particular, in interpretations of locales with
  1815 predicates, goals repesenting already interpreted fragments are not
  1816 removed automatically.  Use methods `intro_locales' and
  1817 `unfold_locales'; see below.
  1818 
  1819 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1820 provide backward reasoning on locales predicates.  The methods are
  1821 aware of interpretations and discharge corresponding goals.
  1822 `intro_locales' is less aggressive then `unfold_locales' and does not
  1823 unfold predicates to assumptions.
  1824 
  1825 * Isar/locales: the order in which locale fragments are accumulated
  1826 has changed.  This enables to override declarations from fragments due
  1827 to interpretations -- for example, unwanted simp rules.
  1828 
  1829 * Isar/locales: interpretation in theories and proof contexts has been
  1830 extended.  One may now specify (and prove) equations, which are
  1831 unfolded in interpreted theorems.  This is useful for replacing
  1832 defined concepts (constants depending on locale parameters) by
  1833 concepts already existing in the target context.  Example:
  1834 
  1835   interpretation partial_order ["op <= :: [int, int] => bool"]
  1836     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1837 
  1838 Typically, the constant `partial_order.less' is created by a
  1839 definition specification element in the context of locale
  1840 partial_order.
  1841 
  1842 * Method "induct": improved internal context management to support
  1843 local fixes and defines on-the-fly. Thus explicit meta-level
  1844 connectives !!  and ==> are rarely required anymore in inductive goals
  1845 (using object-logic connectives for this purpose has been long
  1846 obsolete anyway). Common proof patterns are explained in
  1847 src/HOL/Induct/Common_Patterns.thy, see also
  1848 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1849 examples.
  1850 
  1851 * Method "induct": improved handling of simultaneous goals. Instead of
  1852 introducing object-level conjunction, the statement is now split into
  1853 several conclusions, while the corresponding symbolic cases are nested
  1854 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1855 see src/HOL/Induct/Common_Patterns.thy, for example.
  1856 
  1857 * Method "induct": mutual induction rules are now specified as a list
  1858 of rule sharing the same induction cases. HOL packages usually provide
  1859 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1860 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1861 mutual induction rules differently, i.e. like this:
  1862 
  1863   (induct rule: foo_bar.inducts)
  1864   (induct set: foo bar)
  1865   (induct pred: foo bar)
  1866   (induct type: foo bar)
  1867 
  1868 The ML function ProjectRule.projections turns old-style rules into the
  1869 new format.
  1870 
  1871 * Method "coinduct": dual of induction, see
  1872 src/HOL/Library/Coinductive_List.thy for various examples.
  1873 
  1874 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1875 considered a legacy feature.
  1876 
  1877 * Attribute "symmetric" produces result with standardized schematic
  1878 variables (index 0).  Potential INCOMPATIBILITY.
  1879 
  1880 * Simplifier: by default the simplifier trace only shows top level
  1881 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1882 default. Thus there is less danger of being flooded by the trace. The
  1883 trace indicates where parts have been suppressed.
  1884   
  1885 * Provers/classical: removed obsolete classical version of elim_format
  1886 attribute; classical elim/dest rules are now treated uniformly when
  1887 manipulating the claset.
  1888 
  1889 * Provers/classical: stricter checks to ensure that supplied intro,
  1890 dest and elim rules are well-formed; dest and elim rules must have at
  1891 least one premise.
  1892 
  1893 * Provers/classical: attributes dest/elim/intro take an optional
  1894 weight argument for the rule (just as the Pure versions).  Weights are
  1895 ignored by automated tools, but determine the search order of single
  1896 rule steps.
  1897 
  1898 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1899 where the body does not mention the bound variable.  Note that dummy
  1900 patterns implicitly depend on their context of bounds, which makes
  1901 "{_. _}" match any set comprehension as expected.  Potential
  1902 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1903 constant "_idtdummy" in the binding position.
  1904 
  1905 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1906 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1907 for example "A -> B" => "Pi A (%_. B)".
  1908 
  1909 * Pure: 'class_deps' command visualizes the subclass relation, using
  1910 the graph browser tool.
  1911 
  1912 * Pure: 'print_theory' now suppresses certain internal declarations by
  1913 default; use '!' option for full details.
  1914 
  1915 
  1916 *** HOL ***
  1917 
  1918 * Method "metis" proves goals by applying the Metis general-purpose
  1919 resolution prover (see also http://gilith.com/software/metis/).
  1920 Examples are in the directory MetisExamples.  WARNING: the
  1921 Isabelle/HOL-Metis integration does not yet work properly with
  1922 multi-threading.
  1923   
  1924 * Command 'sledgehammer' invokes external automatic theorem provers as
  1925 background processes.  It generates calls to the "metis" method if
  1926 successful. These can be pasted into the proof.  Users do not have to
  1927 wait for the automatic provers to return.  WARNING: does not really
  1928 work with multi-threading.
  1929 
  1930 * New "auto_quickcheck" feature tests outermost goal statements for
  1931 potential counter-examples.  Controlled by ML references
  1932 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1933 5000 milliseconds).  Fails silently if statements is outside of
  1934 executable fragment, or any other codgenerator problem occurs.
  1935 
  1936 * New constant "undefined" with axiom "undefined x = undefined".
  1937 
  1938 * Added class "HOL.eq", allowing for code generation with polymorphic
  1939 equality.
  1940 
  1941 * Some renaming of class constants due to canonical name prefixing in
  1942 the new 'class' package:
  1943 
  1944     HOL.abs ~> HOL.abs_class.abs
  1945     HOL.divide ~> HOL.divide_class.divide
  1946     0 ~> HOL.zero_class.zero
  1947     1 ~> HOL.one_class.one
  1948     op + ~> HOL.plus_class.plus
  1949     op - ~> HOL.minus_class.minus
  1950     uminus ~> HOL.minus_class.uminus
  1951     op * ~> HOL.times_class.times
  1952     op < ~> HOL.ord_class.less
  1953     op <= > HOL.ord_class.less_eq
  1954     Nat.power ~> Power.power_class.power
  1955     Nat.size ~> Nat.size_class.size
  1956     Numeral.number_of ~> Numeral.number_class.number_of
  1957     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1958     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1959     Orderings.min ~> Orderings.ord_class.min
  1960     Orderings.max ~> Orderings.ord_class.max
  1961     Divides.op div ~> Divides.div_class.div
  1962     Divides.op mod ~> Divides.div_class.mod
  1963     Divides.op dvd ~> Divides.div_class.dvd
  1964 
  1965 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1966 
  1967 a) User-defined constants using any of the names "plus", "minus",
  1968 "times", "less" or "less_eq". The standard syntax translations for
  1969 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1970 names.
  1971 
  1972 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1973 INCOMPATIBILITY: use more specific names.
  1974 
  1975 c) Permutative equations (e.g. "a + b = b + a")
  1976 Since the change of names also changes the order of terms, permutative
  1977 rewrite rules may get applied in a different order. Experience shows
  1978 that this is rarely the case (only two adaptions in the whole Isabelle
  1979 distribution).  INCOMPATIBILITY: rewrite proofs
  1980 
  1981 d) ML code directly refering to constant names
  1982 This in general only affects hand-written proof tactics, simprocs and
  1983 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1984 Consider using @{const_name} antiquotation.
  1985 
  1986 * New class "default" with associated constant "default".
  1987 
  1988 * Function "sgn" is now overloaded and available on int, real, complex
  1989 (and other numeric types), using class "sgn".  Two possible defs of
  1990 sgn are given as equational assumptions in the classes sgn_if and
  1991 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1992 INCOMPATIBILITY.
  1993 
  1994 * Locale "partial_order" now unified with class "order" (cf. theory
  1995 Orderings), added parameter "less".  INCOMPATIBILITY.
  1996 
  1997 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1998 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1999 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2000 
  2001 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2002 changed order of proof goals in instance proofs.
  2003 
  2004 * The transitivity reasoner for partial and linear orders is set up
  2005 for classes "order" and "linorder".  Instances of the reasoner are available
  2006 in all contexts importing or interpreting the corresponding locales.
  2007 Method "order" invokes the reasoner separately; the reasoner
  2008 is also integrated with the Simplifier as a solver.  Diagnostic
  2009 command 'print_orders' shows the available instances of the reasoner
  2010 in the current context.
  2011 
  2012 * Localized monotonicity predicate in theory "Orderings"; integrated
  2013 lemmas max_of_mono and min_of_mono with this predicate.
  2014 INCOMPATIBILITY.
  2015 
  2016 * Formulation of theorem "dense" changed slightly due to integration
  2017 with new class dense_linear_order.
  2018 
  2019 * Uniform lattice theory development in HOL.
  2020 
  2021     constants "meet" and "join" now named "inf" and "sup"
  2022     constant "Meet" now named "Inf"
  2023 
  2024     classes "meet_semilorder" and "join_semilorder" now named
  2025       "lower_semilattice" and "upper_semilattice"
  2026     class "lorder" now named "lattice"
  2027     class "comp_lat" now named "complete_lattice"
  2028 
  2029     Instantiation of lattice classes allows explicit definitions
  2030     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2031 
  2032   INCOMPATIBILITY.  Theorem renames:
  2033 
  2034     meet_left_le            ~> inf_le1
  2035     meet_right_le           ~> inf_le2
  2036     join_left_le            ~> sup_ge1
  2037     join_right_le           ~> sup_ge2
  2038     meet_join_le            ~> inf_sup_ord
  2039     le_meetI                ~> le_infI
  2040     join_leI                ~> le_supI
  2041     le_meet                 ~> le_inf_iff
  2042     le_join                 ~> ge_sup_conv
  2043     meet_idempotent         ~> inf_idem
  2044     join_idempotent         ~> sup_idem
  2045     meet_comm               ~> inf_commute
  2046     join_comm               ~> sup_commute
  2047     meet_leI1               ~> le_infI1
  2048     meet_leI2               ~> le_infI2
  2049     le_joinI1               ~> le_supI1
  2050     le_joinI2               ~> le_supI2
  2051     meet_assoc              ~> inf_assoc
  2052     join_assoc              ~> sup_assoc
  2053     meet_left_comm          ~> inf_left_commute
  2054     meet_left_idempotent    ~> inf_left_idem
  2055     join_left_comm          ~> sup_left_commute
  2056     join_left_idempotent    ~> sup_left_idem
  2057     meet_aci                ~> inf_aci
  2058     join_aci                ~> sup_aci
  2059     le_def_meet             ~> le_iff_inf
  2060     le_def_join             ~> le_iff_sup
  2061     join_absorp2            ~> sup_absorb2
  2062     join_absorp1            ~> sup_absorb1
  2063     meet_absorp1            ~> inf_absorb1
  2064     meet_absorp2            ~> inf_absorb2
  2065     meet_join_absorp        ~> inf_sup_absorb
  2066     join_meet_absorp        ~> sup_inf_absorb
  2067     distrib_join_le         ~> distrib_sup_le
  2068     distrib_meet_le         ~> distrib_inf_le
  2069 
  2070     add_meet_distrib_left   ~> add_inf_distrib_left
  2071     add_join_distrib_left   ~> add_sup_distrib_left
  2072     is_join_neg_meet        ~> is_join_neg_inf
  2073     is_meet_neg_join        ~> is_meet_neg_sup
  2074     add_meet_distrib_right  ~> add_inf_distrib_right
  2075     add_join_distrib_right  ~> add_sup_distrib_right
  2076     add_meet_join_distribs  ~> add_sup_inf_distribs
  2077     join_eq_neg_meet        ~> sup_eq_neg_inf
  2078     meet_eq_neg_join        ~> inf_eq_neg_sup
  2079     add_eq_meet_join        ~> add_eq_inf_sup
  2080     meet_0_imp_0            ~> inf_0_imp_0
  2081     join_0_imp_0            ~> sup_0_imp_0
  2082     meet_0_eq_0             ~> inf_0_eq_0
  2083     join_0_eq_0             ~> sup_0_eq_0
  2084     neg_meet_eq_join        ~> neg_inf_eq_sup
  2085     neg_join_eq_meet        ~> neg_sup_eq_inf
  2086     join_eq_if              ~> sup_eq_if
  2087 
  2088     mono_meet               ~> mono_inf
  2089     mono_join               ~> mono_sup
  2090     meet_bool_eq            ~> inf_bool_eq
  2091     join_bool_eq            ~> sup_bool_eq
  2092     meet_fun_eq             ~> inf_fun_eq
  2093     join_fun_eq             ~> sup_fun_eq
  2094     meet_set_eq             ~> inf_set_eq
  2095     join_set_eq             ~> sup_set_eq
  2096     meet1_iff               ~> inf1_iff
  2097     meet2_iff               ~> inf2_iff
  2098     meet1I                  ~> inf1I
  2099     meet2I                  ~> inf2I
  2100     meet1D1                 ~> inf1D1
  2101     meet2D1                 ~> inf2D1
  2102     meet1D2                 ~> inf1D2
  2103     meet2D2                 ~> inf2D2
  2104     meet1E                  ~> inf1E
  2105     meet2E                  ~> inf2E
  2106     join1_iff               ~> sup1_iff
  2107     join2_iff               ~> sup2_iff
  2108     join1I1                 ~> sup1I1
  2109     join2I1                 ~> sup2I1
  2110     join1I1                 ~> sup1I1
  2111     join2I2                 ~> sup1I2
  2112     join1CI                 ~> sup1CI
  2113     join2CI                 ~> sup2CI
  2114     join1E                  ~> sup1E
  2115     join2E                  ~> sup2E
  2116 
  2117     is_meet_Meet            ~> is_meet_Inf
  2118     Meet_bool_def           ~> Inf_bool_def
  2119     Meet_fun_def            ~> Inf_fun_def
  2120     Meet_greatest           ~> Inf_greatest
  2121     Meet_lower              ~> Inf_lower
  2122     Meet_set_def            ~> Inf_set_def
  2123 
  2124     Sup_def                 ~> Sup_Inf
  2125     Sup_bool_eq             ~> Sup_bool_def
  2126     Sup_fun_eq              ~> Sup_fun_def
  2127     Sup_set_eq              ~> Sup_set_def
  2128 
  2129     listsp_meetI            ~> listsp_infI
  2130     listsp_meet_eq          ~> listsp_inf_eq
  2131 
  2132     meet_min                ~> inf_min
  2133     join_max                ~> sup_max
  2134 
  2135 * Added syntactic class "size"; overloaded constant "size" now has
  2136 type "'a::size ==> bool"
  2137 
  2138 * Internal reorganisation of `size' of datatypes: size theorems
  2139 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2140 simplification rules by default!); theorems "prod.size" now named
  2141 "*.size".
  2142 
  2143 * Class "div" now inherits from class "times" rather than "type".
  2144 INCOMPATIBILITY.
  2145 
  2146 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2147 Linorder etc.  have disappeared; operations defined in terms of
  2148 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2149 
  2150 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2151 
  2152 * HOL-Word: New extensive library and type for generic, fixed size
  2153 machine words, with arithemtic, bit-wise, shifting and rotating
  2154 operations, reflection into int, nat, and bool lists, automation for
  2155 linear arithmetic (by automatic reflection into nat or int), including
  2156 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2157 arithmetic type classes, supporting automatic simplification of
  2158 numerals on all operations.
  2159 
  2160 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2161 
  2162 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2163 
  2164 * Code generator library theories:
  2165   - Code_Integer represents HOL integers by big integer literals in target
  2166     languages.
  2167   - Code_Char represents HOL characters by character literals in target
  2168     languages.
  2169   - Code_Char_chr like Code_Char, but also offers treatment of character
  2170     codes; includes Code_Integer.
  2171   - Executable_Set allows to generate code for finite sets using lists.
  2172   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2173     denominator).
  2174   - Executable_Real implements a subset of real numbers, namly those
  2175     representable by rational numbers.
  2176   - Efficient_Nat implements natural numbers by integers, which in general will
  2177     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2178     includes Code_Integer.
  2179   - Code_Index provides an additional datatype index which is mapped to
  2180     target-language built-in integers.
  2181   - Code_Message provides an additional datatype message_string which is isomorphic to
  2182     strings; messages are mapped to target-language strings.
  2183 
  2184 * New package for inductive predicates
  2185 
  2186   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2187 
  2188     inductive
  2189       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2190       for z_1 :: U_1 and ... and z_n :: U_m
  2191     where
  2192       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2193     | ...
  2194 
  2195   with full support for type-inference, rather than
  2196 
  2197     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2198 
  2199     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2200     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2201 
  2202     inductive "s z_1 ... z_m"
  2203     intros
  2204       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2205       ...
  2206 
  2207   For backward compatibility, there is a wrapper allowing inductive
  2208   sets to be defined with the new package via
  2209 
  2210     inductive_set
  2211       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2212       for z_1 :: U_1 and ... and z_n :: U_m
  2213     where
  2214       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2215     | ...
  2216 
  2217   or
  2218 
  2219     inductive_set
  2220       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2221       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2222       for z_1 :: U_1 and ... and z_n :: U_m
  2223     where
  2224       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2225     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2226     | ...
  2227 
  2228   if the additional syntax "p ..." is required.
  2229 
  2230   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2231   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2232 
  2233   INCOMPATIBILITIES:
  2234 
  2235   - Since declaration and definition of inductive sets or predicates
  2236     is no longer separated, abbreviations involving the newly
  2237     introduced sets or predicates must be specified together with the
  2238     introduction rules after the 'where' keyword (see above), rather
  2239     than before the actual inductive definition.
  2240 
  2241   - The variables in induction and elimination rules are now
  2242     quantified in the order of their occurrence in the introduction
  2243     rules, rather than in alphabetical order. Since this may break
  2244     some proofs, these proofs either have to be repaired, e.g. by
  2245     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2246     statements of the form
  2247 
  2248       case (rule_i a_i_1 ... a_i_{k_i})
  2249 
  2250     or the old order of quantification has to be restored by explicitly adding
  2251     meta-level quantifiers in the introduction rules, i.e.
  2252 
  2253       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2254 
  2255   - The format of the elimination rules is now
  2256 
  2257       p z_1 ... z_m x_1 ... x_n ==>
  2258         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2259         ==> ... ==> P
  2260 
  2261     for predicates and
  2262 
  2263       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2264         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2265         ==> ... ==> P
  2266 
  2267     for sets rather than
  2268 
  2269       x : s z_1 ... z_m ==>
  2270         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2271         ==> ... ==> P
  2272 
  2273     This may require terms in goals to be expanded to n-tuples
  2274     (e.g. using case_tac or simplification with the split_paired_all
  2275     rule) before the above elimination rule is applicable.
  2276 
  2277   - The elimination or case analysis rules for (mutually) inductive
  2278     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2279     list of rules "p_1_..._p_k.elims" is no longer available.
  2280 
  2281 * New package "function"/"fun" for general recursive functions,
  2282 supporting mutual and nested recursion, definitions in local contexts,
  2283 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2284 for small examples, and the separate tutorial on the function
  2285 package. The old recdef "package" is still available as before, but
  2286 users are encouraged to use the new package.
  2287 
  2288 * Method "lexicographic_order" automatically synthesizes termination
  2289 relations as lexicographic combinations of size measures. 
  2290 
  2291 * Case-expressions allow arbitrary constructor-patterns (including
  2292 "_") and take their order into account, like in functional
  2293 programming.  Internally, this is translated into nested
  2294 case-expressions; missing cases are added and mapped to the predefined
  2295 constant "undefined". In complicated cases printing may no longer show
  2296 the original input but the internal form. Lambda-abstractions allow
  2297 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2298 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2299 variable.
  2300 
  2301 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2302 is an abbreviation for "of_nat :: nat => int". The simplification
  2303 rules for "of_nat" have been changed to work like "int" did
  2304 previously.  Potential INCOMPATIBILITY:
  2305   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2306   - of_nat_diff and of_nat_mult are no longer default simp rules
  2307 
  2308 * Method "algebra" solves polynomial equations over (semi)rings using
  2309 Groebner bases. The (semi)ring structure is defined by locales and the
  2310 tool setup depends on that generic context. Installing the method for
  2311 a specific type involves instantiating the locale and possibly adding
  2312 declarations for computation on the coefficients.  The method is
  2313 already instantiated for natural numbers and for the axiomatic class
  2314 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2315 CALCULEMUS 2007 for the general principles underlying this
  2316 architecture of context-aware proof-tools.
  2317 
  2318 * Method "ferrack" implements quantifier elimination over
  2319 special-purpose dense linear orders using locales (analogous to
  2320 "algebra"). The method is already installed for class
  2321 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2322 rat, etc.
  2323 
  2324 * Former constant "List.op @" now named "List.append".  Use ML
  2325 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2326 circumvent possible incompatibilities when working on ML level.
  2327 
  2328 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2329 
  2330 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2331 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2332 
  2333 * New syntax for Haskell-like list comprehension (input only), eg.
  2334 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2335 
  2336 * The special syntax for function "filter" has changed from [x :
  2337 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2338 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2339 
  2340 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2341 defined on nat only, as an abbreviation for [a..<Suc b]
  2342 INCOMPATIBILITY.
  2343 
  2344 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2345 
  2346 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2347 
  2348 * New lemma collection field_simps (an extension of ring_simps) for
  2349 manipulating (in)equations involving division. Multiplies with all
  2350 denominators that can be proved to be non-zero (in equations) or
  2351 positive/negative (in inequations).
  2352 
  2353 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2354 have been improved and renamed to ring_simps, group_simps and
  2355 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2356 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2357 
  2358 * Theory Library/Commutative_Ring: switched from recdef to function
  2359 package; constants add, mul, pow now curried.  Infix syntax for
  2360 algebraic operations.
  2361 
  2362 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2363 INCOMPATIBILITY.
  2364 
  2365 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2366 INCOMPATIBILITY.
  2367 
  2368 * HOL/records: generalised field-update to take a function on the
  2369 field rather than the new value: r(|A := x|) is translated to A_update
  2370 (K x) r The K-combinator that is internally used is called K_record.
  2371 INCOMPATIBILITY: Usage of the plain update functions has to be
  2372 adapted.
  2373  
  2374 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2375 * x = 0, which are required for a semiring.  Richer structures do not
  2376 inherit from semiring_0 anymore, because this property is a theorem
  2377 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2378 there is more to prove, but this is mostly trivial.
  2379 
  2380 * Class "recpower" is generalized to arbitrary monoids, not just
  2381 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2382 commutativity or semiring properties additionally.
  2383 
  2384 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2385 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2386 better use 'abbreviation'.
  2387 
  2388 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2389 
  2390 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2391 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2392 significant changes for setting up numeral syntax for types:
  2393   - New constants Numeral.pred and Numeral.succ instead
  2394       of former Numeral.bin_pred and Numeral.bin_succ.
  2395   - Use integer operations instead of bin_add, bin_mult and so on.
  2396   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2397   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2398 
  2399 See src/HOL/Integ/IntArith.thy for an example setup.
  2400 
  2401 * Command 'normal_form' computes the normal form of a term that may
  2402 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2403 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2404 heavy-duty computations because the functions are compiled to ML
  2405 first.  Correspondingly, a method "normalization" is provided.  See
  2406 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2407 
  2408 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2409 25 like -->); output depends on the "iff" print_mode, the default is
  2410 "A = B" (with priority 50).
  2411 
  2412 * Relations less (<) and less_eq (<=) are also available on type bool.
  2413 Modified syntax to disallow nesting without explicit parentheses,
  2414 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2415 INCOMPATIBILITY.
  2416 
  2417 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2418 
  2419 * Relation composition operator "op O" now has precedence 75 and binds
  2420 stronger than union and intersection. INCOMPATIBILITY.
  2421 
  2422 * The old set interval syntax "{m..n(}" (and relatives) has been
  2423 removed.  Use "{m..<n}" (and relatives) instead.
  2424 
  2425 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2426 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2427 ``declare [[simproc del: neq]]''.
  2428 
  2429 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2430 True/False.
  2431 
  2432 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2433 
  2434 * Theorem setsum_mult renamed to setsum_right_distrib.
  2435 
  2436 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2437 ``rule'' method.
  2438 
  2439 * Reimplemented methods "sat" and "satx", with several improvements:
  2440 goals no longer need to be stated as "<prems> ==> False", equivalences
  2441 (i.e. "=" on type bool) are handled, variable names of the form
  2442 "lit_<n>" are no longer reserved, significant speedup.
  2443 
  2444 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2445 zChaff is still supported as well.
  2446 
  2447 * 'inductive' and 'datatype': provide projections of mutual rules,
  2448 bundled as foo_bar.inducts;
  2449 
  2450 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2451 Library.
  2452 
  2453 * Library: moved theory Accessible_Part to main HOL.
  2454 
  2455 * Library: added theory Coinductive_List of potentially infinite lists
  2456 as greatest fixed-point.
  2457 
  2458 * Library: added theory AssocList which implements (finite) maps as
  2459 association lists.
  2460 
  2461 * Method "evaluation" solves goals (i.e. a boolean expression)
  2462 efficiently by compiling it to ML.  The goal is "proved" (via an
  2463 oracle) if it evaluates to True.
  2464 
  2465 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2466 also when invoked by the simplifier.  This results in the Simplifier
  2467 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2468 Configuration option fast_arith_split_limit=0 recovers the old
  2469 behavior.
  2470 
  2471 * Support for hex (0x20) and binary (0b1001) numerals.
  2472 
  2473 * New method: reify eqs (t), where eqs are equations for an
  2474 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2475 parameter, computes a term s::'b and a list xs::'a list and proves the
  2476 theorem I xs s = t. This is also known as reification or quoting. The
  2477 resulting theorem is applied to the subgoal to substitute t with I xs
  2478 s.  If t is omitted, the subgoal itself is reified.
  2479 
  2480 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2481 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2482 where f is supposed to be a computable function (in the sense of code
  2483 generattion). The method uses reify to compute s and xs as above then
  2484 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2485 r and finally gets the theorem t = r, which is again applied to the
  2486 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2487 
  2488 * Reflection: Automatic reification now handels binding, an example is
  2489 available in src/HOL/ex/ReflectionEx.thy
  2490 
  2491 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2492 command 'statespace' that is similar to 'record', but introduces an
  2493 abstract specification based on the locale infrastructure instead of
  2494 HOL types.  This leads to extra flexibility in composing state spaces,
  2495 in particular multiple inheritance and renaming of components.
  2496 
  2497 
  2498 *** HOL-Complex ***
  2499 
  2500 * Hyperreal: Functions root and sqrt are now defined on negative real
  2501 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2502 Nonnegativity side conditions have been removed from many lemmas, so
  2503 that more subgoals may now be solved by simplification; potential
  2504 INCOMPATIBILITY.
  2505 
  2506 * Real: new type classes formalize real normed vector spaces and
  2507 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2508 and norm :: 'a => real.
  2509 
  2510 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2511 reals into other types. The overloaded constant Reals :: 'a set is now
  2512 defined as range of_real; potential INCOMPATIBILITY.
  2513 
  2514 * Real: proper support for ML code generation, including 'quickcheck'.
  2515 Reals are implemented as arbitrary precision rationals.
  2516 
  2517 * Hyperreal: Several constants that previously worked only for the
  2518 reals have been generalized, so they now work over arbitrary vector
  2519 spaces. Type annotations may need to be added in some cases; potential
  2520 INCOMPATIBILITY.
  2521 
  2522   Infinitesimal  :: ('a::real_normed_vector) star set
  2523   HFinite        :: ('a::real_normed_vector) star set
  2524   HInfinite      :: ('a::real_normed_vector) star set
  2525   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2526   monad          :: ('a::real_normed_vector) star => 'a star set
  2527   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2528   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2529   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2530   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2531   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2532   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2533   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2534   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2535   sgn            :: 'a::real_normed_vector => 'a
  2536   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2537 
  2538 * Complex: Some complex-specific constants are now abbreviations for
  2539 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2540 hnorm.  Other constants have been entirely removed in favor of the
  2541 polymorphic versions (INCOMPATIBILITY):
  2542 
  2543   approx        <-- capprox
  2544   HFinite       <-- CFinite
  2545   HInfinite     <-- CInfinite
  2546   Infinitesimal <-- CInfinitesimal
  2547   monad         <-- cmonad
  2548   galaxy        <-- cgalaxy
  2549   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2550   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2551   (ns)deriv     <-- (ns)cderiv
  2552 
  2553 
  2554 *** HOL-Algebra ***
  2555 
  2556 * Formalisation of ideals and the quotient construction over rings.
  2557 
  2558 * Order and lattice theory no longer based on records.
  2559 INCOMPATIBILITY.
  2560 
  2561 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2562 greatest_closed.  INCOMPATIBILITY.
  2563 
  2564 * Method algebra is now set up via an attribute.  For examples see
  2565 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2566 of algebraic structures.
  2567 
  2568 * Renamed theory CRing to Ring.
  2569 
  2570 
  2571 *** HOL-Nominal ***
  2572 
  2573 * Substantial, yet incomplete support for nominal datatypes (binding
  2574 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2575 src/HOL/Nominal/Examples.  Prospective users should consult
  2576 http://isabelle.in.tum.de/nominal/
  2577 
  2578 
  2579 *** ML ***
  2580 
  2581 * ML basics: just one true type int, which coincides with IntInf.int
  2582 (even on SML/NJ).
  2583 
  2584 * ML within Isar: antiquotations allow to embed statically-checked
  2585 formal entities in the source, referring to the context available at
  2586 compile-time.  For example:
  2587 
  2588 ML {* @{sort "{zero,one}"} *}
  2589 ML {* @{typ "'a => 'b"} *}
  2590 ML {* @{term "%x. x"} *}
  2591 ML {* @{prop "x == y"} *}
  2592 ML {* @{ctyp "'a => 'b"} *}
  2593 ML {* @{cterm "%x. x"} *}
  2594 ML {* @{cprop "x == y"} *}
  2595 ML {* @{thm asm_rl} *}
  2596 ML {* @{thms asm_rl} *}
  2597 ML {* @{type_name c} *}
  2598 ML {* @{type_syntax c} *}
  2599 ML {* @{const_name c} *}
  2600 ML {* @{const_syntax c} *}
  2601 ML {* @{context} *}
  2602 ML {* @{theory} *}
  2603 ML {* @{theory Pure} *}
  2604 ML {* @{theory_ref} *}
  2605 ML {* @{theory_ref Pure} *}
  2606 ML {* @{simpset} *}
  2607 ML {* @{claset} *}
  2608 ML {* @{clasimpset} *}
  2609 
  2610 The same works for sources being ``used'' within an Isar context.
  2611 
  2612 * ML in Isar: improved error reporting; extra verbosity with
  2613 ML_Context.trace enabled.
  2614 
  2615 * Pure/General/table.ML: the join operations now works via exceptions
  2616 DUP/SAME instead of type option. This is simpler in simple cases, and
  2617 admits slightly more efficient complex applications.
  2618 
  2619 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2620 use Context.generic instead of just theory.
  2621 
  2622 * Pure: datatype Context.generic joins theory/Proof.context and
  2623 provides some facilities for code that works in either kind of
  2624 context, notably GenericDataFun for uniform theory and proof data.
  2625 
  2626 * Pure: simplified internal attribute type, which is now always
  2627 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2628 local (Proof.context) attributes have been discontinued, while
  2629 minimizing code duplication. Thm.rule_attribute and
  2630 Thm.declaration_attribute build canonical attributes; see also structure
  2631 Context for further operations on Context.generic, notably
  2632 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2633 declarations and definitions.
  2634 
  2635 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2636 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2637 init only required for impure data. INCOMPATIBILITY: empty really need
  2638 to be empty (no dependencies on theory content!)
  2639 
  2640 * Pure/kernel: consts certification ignores sort constraints given in
  2641 signature declarations. (This information is not relevant to the
  2642 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2643 potential INCOMPATIBILITY.
  2644 
  2645 * Pure: axiomatic type classes are now purely definitional, with
  2646 explicit proofs of class axioms and super class relations performed
  2647 internally. See Pure/axclass.ML for the main internal interfaces --
  2648 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2649 AxClass.axiomatize_class/classrel/arity supersede
  2650 Sign.add_classes/classrel/arities.
  2651 
  2652 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2653 global/local versions on theory vs. Proof.context have been
  2654 discontinued; Attrib.syntax and Method.syntax have been adapted
  2655 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2656 attributes, methods, etc.
  2657 
  2658 * Pure: several functions of signature "... -> theory -> theory * ..."
  2659 have been reoriented to "... -> theory -> ... * theory" in order to
  2660 allow natural usage in combination with the ||>, ||>>, |-> and
  2661 fold_map combinators.
  2662 
  2663 * Pure: official theorem names (closed derivations) and additional
  2664 comments (tags) are now strictly separate.  Name hints -- which are
  2665 maintained as tags -- may be attached any time without affecting the
  2666 derivation.
  2667 
  2668 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2669 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2670 achieve the old behaviour.
  2671 
  2672 * Pure: the "Goal" constant is now called "prop", supporting a
  2673 slightly more general idea of ``protecting'' meta-level rule
  2674 statements.
  2675 
  2676 * Pure: Logic.(un)varify only works in a global context, which is now
  2677 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2678 Logic.legacy_(un)varify as temporary workaround.
  2679 
  2680 * Pure: structure Name provides scalable operations for generating
  2681 internal variable names, notably Name.variants etc.  This replaces
  2682 some popular functions from term.ML:
  2683 
  2684   Term.variant		->  Name.variant
  2685   Term.variantlist	->  Name.variant_list
  2686   Term.invent_names	->  Name.invent_list
  2687 
  2688 Note that low-level renaming rarely occurs in new code -- operations
  2689 from structure Variable are used instead (see below).
  2690 
  2691 * Pure: structure Variable provides fundamental operations for proper
  2692 treatment of fixed/schematic variables in a context.  For example,
  2693 Variable.import introduces fixes for schematics of given facts and
  2694 Variable.export reverses the effect (up to renaming) -- this replaces
  2695 various freeze_thaw operations.
  2696 
  2697 * Pure: structure Goal provides simple interfaces for
  2698 init/conclude/finish and tactical prove operations (replacing former
  2699 Tactic.prove).  Goal.prove is the canonical way to prove results
  2700 within a given context; Goal.prove_global is a degraded version for
  2701 theory level goals, including a global Drule.standard.  Note that
  2702 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2703 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2704 in a locale context).
  2705 
  2706 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2707 and type checking (Syntax.check_term etc.), with common combinations
  2708 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2709 which are considered legacy and await removal.
  2710 
  2711 * Pure/Syntax: generic interfaces for type unchecking
  2712 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2713 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2714 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2715 available for convenience, but refer to the very same operations using
  2716 a mere theory instead of a full context.
  2717 
  2718 * Isar: simplified treatment of user-level errors, using exception
  2719 ERROR of string uniformly.  Function error now merely raises ERROR,
  2720 without any side effect on output channels.  The Isar toplevel takes
  2721 care of proper display of ERROR exceptions.  ML code may use plain
  2722 handle/can/try; cat_error may be used to concatenate errors like this:
  2723 
  2724   ... handle ERROR msg => cat_error msg "..."
  2725 
  2726 Toplevel ML code (run directly or through the Isar toplevel) may be
  2727 embedded into the Isar toplevel with exception display/debug like
  2728 this:
  2729 
  2730   Isar.toplevel (fn () => ...)
  2731 
  2732 INCOMPATIBILITY, removed special transform_error facilities, removed
  2733 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2734 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2735 -- use plain ERROR instead.
  2736 
  2737 * Isar: theory setup now has type (theory -> theory), instead of a
  2738 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2739 
  2740 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2741 ProofContext.debug/verbose flags.
  2742 
  2743 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2744 theory before entering a proof state.  Transactions now always see a
  2745 quasi-functional intermediate checkpoint, both in interactive and
  2746 batch mode.
  2747 
  2748 * Isar: simplified interfaces for outer syntax.  Renamed
  2749 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2750 OuterSyntax.add_parsers -- this functionality is now included in
  2751 OuterSyntax.command etc.  INCOMPATIBILITY.
  2752 
  2753 * Simplifier: the simpset of a running simplification process now
  2754 contains a proof context (cf. Simplifier.the_context), which is the
  2755 very context that the initial simpset has been retrieved from (by
  2756 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2757 (solver, looper etc.) may depend on arbitrary proof data.
  2758 
  2759 * Simplifier.inherit_context inherits the proof context (plus the
  2760 local bounds) of the current simplification process; any simproc
  2761 etc. that calls the Simplifier recursively should do this!  Removed
  2762 former Simplifier.inherit_bounds, which is already included here --
  2763 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2764 specify an explicit context using Simplifier.context/theory_context.
  2765 
  2766 * Simplifier/Classical Reasoner: more abstract interfaces
  2767 change_simpset/claset for modifying the simpset/claset reference of a
  2768 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2769 INCOMPATIBILITY.
  2770 
  2771 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2772 "Trueprop" etc.
  2773 
  2774 
  2775 *** System ***
  2776 
  2777 * settings: the default heap location within ISABELLE_HOME_USER now
  2778 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2779 Isabelle installations.
  2780 
  2781 * isabelle-process: option -S (secure mode) disables some critical
  2782 operations, notably runtime compilation and evaluation of ML source
  2783 code.
  2784 
  2785 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2786 
  2787 * Support for parallel execution, using native multicore support of
  2788 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2789 independent theories, according to the given theory header
  2790 specifications. The maximum number of worker threads is specified via
  2791 usedir option -M or the "max-threads" setting in Proof General. A
  2792 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2793 to 6 on a 8-core machine.  User-code needs to observe certain
  2794 guidelines for thread-safe programming, see appendix A in the Isar
  2795 Implementation manual.
  2796 
  2797 
  2798 
  2799 New in Isabelle2005 (October 2005)
  2800 ----------------------------------
  2801 
  2802 *** General ***
  2803 
  2804 * Theory headers: the new header syntax for Isar theories is
  2805 
  2806   theory <name>
  2807   imports <theory1> ... <theoryN>
  2808   uses <file1> ... <fileM>
  2809   begin
  2810 
  2811 where the 'uses' part is optional.  The previous syntax
  2812 
  2813   theory <name> = <theory1> + ... + <theoryN>:
  2814 
  2815 will disappear in the next release.  Use isatool fixheaders to convert
  2816 existing theory files.  Note that there is no change in ancient
  2817 non-Isar theories now, but these will disappear soon.
  2818 
  2819 * Theory loader: parent theories can now also be referred to via
  2820 relative and absolute paths.
  2821 
  2822 * Command 'find_theorems' searches for a list of criteria instead of a
  2823 list of constants. Known criteria are: intro, elim, dest, name:string,
  2824 simp:term, and any term. Criteria can be preceded by '-' to select
  2825 theorems that do not match. Intro, elim, dest select theorems that
  2826 match the current goal, name:s selects theorems whose fully qualified
  2827 name contain s, and simp:term selects all simplification rules whose
  2828 lhs match term.  Any other term is interpreted as pattern and selects
  2829 all theorems matching the pattern. Available in ProofGeneral under
  2830 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2831 
  2832   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2833 
  2834 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2835 matching the current goal as introduction rule and not having "HOL."
  2836 in their name (i.e. not being defined in theory HOL).
  2837 
  2838 * Command 'thms_containing' has been discontinued in favour of
  2839 'find_theorems'; INCOMPATIBILITY.
  2840 
  2841 * Communication with Proof General is now 8bit clean, which means that
  2842 Unicode text in UTF-8 encoding may be used within theory texts (both
  2843 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2844 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2845 
  2846   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2847   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2848 
  2849 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2850 Classical Reasoner.  Typical big applications run around 2 times
  2851 faster.
  2852 
  2853 
  2854 *** Document preparation ***
  2855 
  2856 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2857 of raw sources.  Only those symbols that do not require additional
  2858 LaTeX packages (depending on comments in isabellesym.sty) are
  2859 displayed properly, everything else is left verbatim.  isatool display
  2860 and isatool print are used as front ends (these are subject to the
  2861 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2862 
  2863 * Command tags control specific markup of certain regions of text,
  2864 notably folding and hiding.  Predefined tags include "theory" (for
  2865 theory begin and end), "proof" for proof commands, and "ML" for
  2866 commands involving ML code; the additional tags "visible" and
  2867 "invisible" are unused by default.  Users may give explicit tag
  2868 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2869 interpretation of tags is determined by the LaTeX job during document
  2870 preparation: see option -V of isatool usedir, or options -n and -t of
  2871 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2872 \isadroptag.
  2873 
  2874 Several document versions may be produced at the same time via isatool
  2875 usedir (the generated index.html will link all of them).  Typical
  2876 specifications include ''-V document=theory,proof,ML'' to present
  2877 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2878 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2879 these parts without any formal replacement text.  The Isabelle site
  2880 default settings produce ''document'' and ''outline'' versions as
  2881 specified above.
  2882 
  2883 * Several new antiquotations:
  2884 
  2885   @{term_type term} prints a term with its type annotated;
  2886 
  2887   @{typeof term} prints the type of a term;
  2888 
  2889   @{const const} is the same as @{term const}, but checks that the
  2890   argument is a known logical constant;
  2891 
  2892   @{term_style style term} and @{thm_style style thm} print a term or
  2893   theorem applying a "style" to it
  2894 
  2895   @{ML text}
  2896 
  2897 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2898 definitions, equations, inequations etc., 'concl' printing only the
  2899 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2900 to print the specified premise.  TermStyle.add_style provides an ML
  2901 interface for introducing further styles.  See also the "LaTeX Sugar"
  2902 document practical applications.  The ML antiquotation prints
  2903 type-checked ML expressions verbatim.
  2904 
  2905 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2906 and 'text' support optional locale specification '(in loc)', which
  2907 specifies the default context for interpreting antiquotations.  For
  2908 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2909 
  2910 * Option 'locale=NAME' of antiquotations specifies an alternative
  2911 context interpreting the subsequent argument.  For example: @{thm
  2912 [locale=lattice] inf_assoc}.
  2913 
  2914 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2915 a proof context.
  2916 
  2917 * Proper output of antiquotations for theory commands involving a
  2918 proof context (such as 'locale' or 'theorem (in loc) ...').
  2919 
  2920 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2921 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2922 
  2923 * isatool usedir: new option -C (default true) controls whether option
  2924 -D should include a copy of the original document directory; -C false
  2925 prevents unwanted effects such as copying of administrative CVS data.
  2926 
  2927 
  2928 *** Pure ***
  2929 
  2930 * Considerably improved version of 'constdefs' command.  Now performs
  2931 automatic type-inference of declared constants; additional support for
  2932 local structure declarations (cf. locales and HOL records), see also
  2933 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2934 sequential dependencies of definitions within a single 'constdefs'
  2935 section; moreover, the declared name needs to be an identifier.  If
  2936 all fails, consider to fall back on 'consts' and 'defs' separately.
  2937 
  2938 * Improved indexed syntax and implicit structures.  First of all,
  2939 indexed syntax provides a notational device for subscripted
  2940 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2941 expressions.  Secondly, in a local context with structure
  2942 declarations, number indexes \<^sub>n or the empty index (default
  2943 number 1) refer to a certain fixed variable implicitly; option
  2944 show_structs controls printing of implicit structures.  Typical
  2945 applications of these concepts involve record types and locales.
  2946 
  2947 * New command 'no_syntax' removes grammar declarations (and
  2948 translations) resulting from the given syntax specification, which is
  2949 interpreted in the same manner as for the 'syntax' command.
  2950 
  2951 * 'Advanced' translation functions (parse_translation etc.) may depend
  2952 on the signature of the theory context being presently used for
  2953 parsing/printing, see also isar-ref manual.
  2954 
  2955 * Improved 'oracle' command provides a type-safe interface to turn an
  2956 ML expression of type theory -> T -> term into a primitive rule of
  2957 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2958 is already included here); see also FOL/ex/IffExample.thy;
  2959 INCOMPATIBILITY.
  2960 
  2961 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2962 before); "cI" is no longer bound, use "c.intro" instead.
  2963 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2964 axclasses vs. locales.
  2965 
  2966 * Improved internal renaming of symbolic identifiers -- attach primes
  2967 instead of base 26 numbers.
  2968 
  2969 * New flag show_question_marks controls printing of leading question
  2970 marks in schematic variable names.
  2971 
  2972 * In schematic variable names, *any* symbol following \<^isub> or
  2973 \<^isup> is now treated as part of the base name.  For example, the
  2974 following works without printing of awkward ".0" indexes:
  2975 
  2976   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2977     by simp
  2978 
  2979 * Inner syntax includes (*(*nested*) comments*).
  2980 
  2981 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2982 annotations as "(00...)".
  2983 
  2984 * Clear separation of logical types and nonterminals, where the latter
  2985 may only occur in 'syntax' specifications or type abbreviations.
  2986 Before that distinction was only partially implemented via type class
  2987 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2988 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2989 exotic syntax specifications may require further adaption
  2990 (e.g. Cube/Cube.thy).
  2991 
  2992 * Removed obsolete type class "logic", use the top sort {} instead.
  2993 Note that non-logical types should be declared as 'nonterminals'
  2994 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2995 specifications.
  2996 
  2997 * Attributes 'induct' and 'cases': type or set names may now be
  2998 locally fixed variables as well.
  2999 
  3000 * Simplifier: can now control the depth to which conditional rewriting
  3001 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3002 Limit.
  3003 
  3004 * Simplifier: simplification procedures may now take the current
  3005 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3006 interface), which is very useful for calling the Simplifier
  3007 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3008 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3009 low-level mk_simproc no longer applies Logic.varify internally, to
  3010 allow for use in a context of fixed variables.
  3011 
  3012 * thin_tac now works even if the assumption being deleted contains !!
  3013 or ==>.  More generally, erule now works even if the major premise of
  3014 the elimination rule contains !! or ==>.
  3015 
  3016 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3017 
  3018 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3019 from Pure, which contains all common declarations already.  Both
  3020 theories are defined via plain Isabelle/Isar .thy files.
  3021 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3022 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3023 use isatool fixcpure to adapt your theory and ML sources.
  3024 
  3025 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3026 selections of theorems in named facts via index ranges.
  3027 
  3028 * 'print_theorems': in theory mode, really print the difference
  3029 wrt. the last state (works for interactive theory development only),
  3030 in proof mode print all local facts (cf. 'print_facts');
  3031 
  3032 * 'hide': option '(open)' hides only base names.
  3033 
  3034 * More efficient treatment of intermediate checkpoints in interactive
  3035 theory development.
  3036 
  3037 * Code generator is now invoked via code_module (incremental code
  3038 generation) and code_library (modular code generation, ML structures
  3039 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3040 must be quoted when used as identifiers.
  3041 
  3042 * New 'value' command for reading, evaluating and printing terms using
  3043 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3044 quoted when used as identifier.
  3045 
  3046 
  3047 *** Locales ***
  3048 
  3049 * New commands for the interpretation of locale expressions in
  3050 theories (1), locales (2) and proof contexts (3).  These generate
  3051 proof obligations from the expression specification.  After the
  3052 obligations have been discharged, theorems of the expression are added
  3053 to the theory, target locale or proof context.  The synopsis of the
  3054 commands is a follows:
  3055 
  3056   (1) interpretation expr inst
  3057   (2) interpretation target < expr
  3058   (3) interpret expr inst
  3059 
  3060 Interpretation in theories and proof contexts require a parameter
  3061 instantiation of terms from the current context.  This is applied to
  3062 specifications and theorems of the interpreted expression.
  3063 Interpretation in locales only permits parameter renaming through the
  3064 locale expression.  Interpretation is smart in that interpretations
  3065 that are active already do not occur in proof obligations, neither are
  3066 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3067 inspect active interpretations of a particular locale.  For details,
  3068 see the Isar Reference manual.  Examples can be found in
  3069 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3070 
  3071 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3072 'interpret' instead.
  3073 
  3074 * New context element 'constrains' for adding type constraints to
  3075 parameters.
  3076 
  3077 * Context expressions: renaming of parameters with syntax
  3078 redeclaration.
  3079 
  3080 * Locale declaration: 'includes' disallowed.
  3081 
  3082 * Proper static binding of attribute syntax -- i.e. types / terms /
  3083 facts mentioned as arguments are always those of the locale definition
  3084 context, independently of the context of later invocations.  Moreover,
  3085 locale operations (renaming and type / term instantiation) are applied
  3086 to attribute arguments as expected.
  3087 
  3088 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3089 actual attributes; rare situations may require Attrib.attribute to
  3090 embed those attributes into Attrib.src that lack concrete syntax.
  3091 Attribute implementations need to cooperate properly with the static
  3092 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3093 Attrib.XXX_thm etc. already do the right thing without further
  3094 intervention.  Only unusual applications -- such as "where" or "of"
  3095 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3096 on the context and the facts involved -- may have to assign parsed
  3097 values to argument tokens explicitly.
  3098 
  3099 * Changed parameter management in theorem generation for long goal
  3100 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3101 theorem statement in rare situations.
  3102 
  3103 * Locale inspection command 'print_locale' omits notes elements.  Use
  3104 'print_locale!' to have them included in the output.
  3105 
  3106 
  3107 *** Provers ***
  3108 
  3109 * Provers/hypsubst.ML: improved version of the subst method, for
  3110 single-step rewriting: it now works in bound variable contexts. New is
  3111 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3112 rewrite a different subterm than the original subst method, which is
  3113 still available as 'simplesubst'.
  3114 
  3115 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3116 and quasi orders.
  3117 
  3118 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3119 reflexive-transitive closure of relations.
  3120 
  3121 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3122 limit (previously hard-coded with a value of 20) user-definable.
  3123 
  3124 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3125 is peformed already.  Object-logics merely need to finish their
  3126 initial simpset configuration as before.  INCOMPATIBILITY.
  3127 
  3128 
  3129 *** HOL ***
  3130 
  3131 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3132 
  3133   syntax (epsilon)
  3134     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3135 
  3136 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3137 and x-symbol; use option '-m epsilon' to get it actually printed.
  3138 Moreover, the mathematically important symbolic identifier \<epsilon>
  3139 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3140 
  3141 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3142 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3143 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3144 support corresponding Isar calculations.
  3145 
  3146 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3147 instead of ":".
  3148 
  3149 * theory SetInterval: changed the syntax for open intervals:
  3150 
  3151   Old       New
  3152   {..n(}    {..<n}
  3153   {)n..}    {n<..}
  3154   {m..n(}   {m..<n}
  3155   {)m..n}   {m<..n}
  3156   {)m..n(}  {m<..<n}
  3157 
  3158 The old syntax is still supported but will disappear in the next
  3159 release.  For conversion use the following Emacs search and replace
  3160 patterns (these are not perfect but work quite well):
  3161 
  3162   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3163   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3164 
  3165 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3166 equalities in commutative rings; method 'algebra' provides a generic
  3167 interface.
  3168 
  3169 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3170 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3171 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3172 be a tuple pattern.
  3173 
  3174 Some new syntax forms are available:
  3175 
  3176   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3177   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3178   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3179   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3180 
  3181 The latter form "\<Sum>x < k. e" used to be based on a separate
  3182 function "Summation", which has been discontinued.
  3183 
  3184 * theory Finite_Set: in structured induction proofs, the insert case
  3185 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3186 (insert F x)'.
  3187 
  3188 * The 'refute' command has been extended to support a much larger
  3189 fragment of HOL, including axiomatic type classes, constdefs and
  3190 typedefs, inductive datatypes and recursion.
  3191 
  3192 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3193 Requires zChaff with proof generation to be installed.  See
  3194 HOL/ex/SAT_Examples.thy for examples.
  3195 
  3196 * Datatype induction via method 'induct' now preserves the name of the
  3197 induction variable. For example, when proving P(xs::'a list) by
  3198 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3199 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3200 in unstructured proof scripts.
  3201 
  3202 * Reworked implementation of records.  Improved scalability for
  3203 records with many fields, avoiding performance problems for type
  3204 inference. Records are no longer composed of nested field types, but
  3205 of nested extension types. Therefore the record type only grows linear
  3206 in the number of extensions and not in the number of fields.  The
  3207 top-level (users) view on records is preserved.  Potential
  3208 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3209 old record representation. The type generated for a record is called
  3210 <record_name>_ext_type.
  3211 
  3212 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3213 proofs triggered by a record definition or a simproc (if
  3214 quick_and_dirty is enabled).  Definitions of large records can take
  3215 quite long.
  3216 
  3217 New simproc record_upd_simproc for simplification of multiple record
  3218 updates enabled by default.  Moreover, trivial updates are also
  3219 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3220 occasionally, since simplification is more powerful by default.
  3221 
  3222 * typedef: proper support for polymorphic sets, which contain extra
  3223 type-variables in the term.
  3224 
  3225 * Simplifier: automatically reasons about transitivity chains
  3226 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3227 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3228 old proofs break occasionally as simplification may now solve more
  3229 goals than previously.
  3230 
  3231 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3232 present.  Works for all partial orders (class "order"), in particular
  3233 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3234 just like y <= x.
  3235 
  3236 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3237 bound variable or a constant then the let is unfolded.  Otherwise
  3238 first a is simplified to b, and then f b is simplified to g. If
  3239 possible we abstract b from g arriving at "let x = b in h x",
  3240 otherwise we unfold the let and arrive at g.  The simproc can be
  3241 enabled/disabled by the reference use_let_simproc.  Potential
  3242 INCOMPATIBILITY since simplification is more powerful by default.
  3243 
  3244 * Classical reasoning: the meson method now accepts theorems as arguments.
  3245 
  3246 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3247 jobs to provide advice on the provability of subgoals.
  3248 
  3249 * Theory OrderedGroup and Ring_and_Field: various additions and
  3250 improvements to faciliate calculations involving equalities and
  3251 inequalities.
  3252 
  3253 The following theorems have been eliminated or modified
  3254 (INCOMPATIBILITY):
  3255 
  3256   abs_eq             now named abs_of_nonneg
  3257   abs_of_ge_0        now named abs_of_nonneg
  3258   abs_minus_eq       now named abs_of_nonpos
  3259   imp_abs_id         now named abs_of_nonneg
  3260   imp_abs_neg_id     now named abs_of_nonpos
  3261   mult_pos           now named mult_pos_pos
  3262   mult_pos_le        now named mult_nonneg_nonneg
  3263   mult_pos_neg_le    now named mult_nonneg_nonpos
  3264   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3265   mult_neg           now named mult_neg_neg
  3266   mult_neg_le        now named mult_nonpos_nonpos
  3267 
  3268 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3269      
  3270      zero_le_square
  3271      not_square_less_zero 
  3272 
  3273   The following lemmas have been deleted from Real/RealPow:
  3274   
  3275      realpow_zero_zero
  3276      realpow_two
  3277      realpow_less
  3278      zero_le_power
  3279      realpow_two_le
  3280      abs_realpow_two
  3281      realpow_two_abs     
  3282 
  3283 * Theory Parity: added rules for simplifying exponents.
  3284 
  3285 * Theory List:
  3286 
  3287 The following theorems have been eliminated or modified
  3288 (INCOMPATIBILITY):
  3289 
  3290   list_all_Nil       now named list_all.simps(1)
  3291   list_all_Cons      now named list_all.simps(2)
  3292   list_all_conv      now named list_all_iff
  3293   set_mem_eq         now named mem_iff
  3294 
  3295 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3296 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3297 
  3298 
  3299 *** HOL-Complex ***
  3300 
  3301 * Theory RealDef: better support for embedding natural numbers and
  3302 integers in the reals.
  3303 
  3304 The following theorems have been eliminated or modified
  3305 (INCOMPATIBILITY):
  3306 
  3307   exp_ge_add_one_self  now requires no hypotheses
  3308   real_of_int_add      reversed direction of equality (use [symmetric])
  3309   real_of_int_minus    reversed direction of equality (use [symmetric])
  3310   real_of_int_diff     reversed direction of equality (use [symmetric])
  3311   real_of_int_mult     reversed direction of equality (use [symmetric])
  3312 
  3313 * Theory RComplete: expanded support for floor and ceiling functions.
  3314 
  3315 * Theory Ln is new, with properties of the natural logarithm
  3316 
  3317 * Hyperreal: There is a new type constructor "star" for making
  3318 nonstandard types.  The old type names are now type synonyms:
  3319 
  3320   hypreal = real star
  3321   hypnat = nat star
  3322   hcomplex = complex star
  3323 
  3324 * Hyperreal: Many groups of similarly-defined constants have been
  3325 replaced by polymorphic versions (INCOMPATIBILITY):
  3326 
  3327   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3328 
  3329   starset      <-- starsetNat, starsetC
  3330   *s*          <-- *sNat*, *sc*
  3331   starset_n    <-- starsetNat_n, starsetC_n
  3332   *sn*         <-- *sNatn*, *scn*
  3333   InternalSets <-- InternalNatSets, InternalCSets
  3334 
  3335   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3336   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3337   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3338   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3339   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3340 
  3341 * Hyperreal: Many type-specific theorems have been removed in favor of
  3342 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3343 
  3344   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3345   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3346   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3347   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3348   right_minus <-- hypreal_add_minus
  3349   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3350   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3351   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3352   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3353   mult_1_right <-- hcomplex_mult_one_right
  3354   mult_zero_left <-- hcomplex_mult_zero_left
  3355   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3356   right_distrib <-- hypnat_add_mult_distrib2
  3357   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3358   right_inverse <-- hypreal_mult_inverse
  3359   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3360   order_refl <-- {hypreal,hypnat}_le_refl
  3361   order_trans <-- {hypreal,hypnat}_le_trans
  3362   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3363   order_less_le <-- {hypreal,hypnat}_less_le
  3364   linorder_linear <-- {hypreal,hypnat}_le_linear
  3365   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3366   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3367   add_nonneg_nonneg <-- hypreal_le_add_order
  3368 
  3369 * Hyperreal: Separate theorems having to do with type-specific
  3370 versions of constants have been merged into theorems that apply to the
  3371 new polymorphic constants (INCOMPATIBILITY):
  3372 
  3373   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3374   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3375   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3376   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3377   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3378   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3379   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3380   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3381   STAR_diff <-- {STAR,STARC}_diff
  3382   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3383     STARC_hcomplex_of_complex}_image_subset
  3384   starset_n_Un <-- starset{Nat,C}_n_Un
  3385   starset_n_Int <-- starset{Nat,C}_n_Int
  3386   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3387   starset_n_diff <-- starset{Nat,C}_n_diff
  3388   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3389   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3390   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3391   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3392   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3393   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3394   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3395   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3396   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3397   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3398   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3399   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3400   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3401   starfun_diff <-- starfun{C,RC,CR}_diff
  3402   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3403   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3404   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3405   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3406   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3407   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3408   starfun_Id <-- starfunC_Id
  3409   starfun_approx <-- starfun{Nat,CR}_approx
  3410   starfun_capprox <-- starfun{C,RC}_capprox
  3411   starfun_abs <-- starfunNat_rabs
  3412   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3413   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3414   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3415   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3416   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3417   starfun_add_approx <-- starfunCR_add_approx
  3418   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3419   starfun_divide <-- starfun{C,CR,RC}_divide
  3420   starfun_n <-- starfun{Nat,C}_n
  3421   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3422   starfun_n_add <-- starfun{Nat,C}_n_add
  3423   starfun_n_add_minus <-- starfunNat_n_add_minus
  3424   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3425   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3426   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3427 
  3428   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3429   star_n_minus <-- {hypreal,hcomplex}_minus
  3430   star_n_diff <-- {hypreal,hcomplex}_diff
  3431   star_n_mult <-- {hypreal,hcomplex}_mult
  3432   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3433   star_n_le <-- {hypreal,hypnat}_le
  3434   star_n_less <-- {hypreal,hypnat}_less
  3435   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3436   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3437   star_n_abs <-- hypreal_hrabs
  3438   star_n_divide <-- hcomplex_divide
  3439 
  3440   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3441   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3442   star_of_diff <-- hypreal_of_real_diff
  3443   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3444   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3445   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3446   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3447   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3448   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3449   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3450   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3451   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3452   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3453   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3454   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3455   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3456   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3457   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3458   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3459   star_of_power <-- hypreal_of_real_power
  3460   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3461 
  3462 * Hyperreal: new method "transfer" that implements the transfer
  3463 principle of nonstandard analysis. With a subgoal that mentions
  3464 nonstandard types like "'a star", the command "apply transfer"
  3465 replaces it with an equivalent one that mentions only standard types.
  3466 To be successful, all free variables must have standard types; non-
  3467 standard variables must have explicit universal quantifiers.
  3468 
  3469 * Hyperreal: A theory of Taylor series.
  3470 
  3471 
  3472 *** HOLCF ***
  3473 
  3474 * Discontinued special version of 'constdefs' (which used to support
  3475 continuous functions) in favor of the general Pure one with full
  3476 type-inference.
  3477 
  3478 * New simplification procedure for solving continuity conditions; it
  3479 is much faster on terms with many nested lambda abstractions (cubic
  3480 instead of exponential time).
  3481 
  3482 * New syntax for domain package: selector names are now optional.
  3483 Parentheses should be omitted unless argument is lazy, for example:
  3484 
  3485   domain 'a stream = cons "'a" (lazy "'a stream")
  3486 
  3487 * New command 'fixrec' for defining recursive functions with pattern
  3488 matching; defining multiple functions with mutual recursion is also
  3489 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3490 sinr, or any data constructor defined by the domain package. The given
  3491 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3492 syntax and examples.
  3493 
  3494 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3495 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3496 but the proof obligation additionally includes an admissibility
  3497 requirement. The packages generate instances of class cpo or pcpo,
  3498 with continuity and strictness theorems for Rep and Abs.
  3499 
  3500 * HOLCF: Many theorems have been renamed according to a more standard naming
  3501 scheme (INCOMPATIBILITY):
  3502 
  3503   foo_inject:  "foo$x = foo$y ==> x = y"
  3504   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3505   foo_less:    "(foo$x << foo$y) = (x << y)"
  3506   foo_strict:  "foo$UU = UU"
  3507   foo_defined: "... ==> foo$x ~= UU"
  3508   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3509 
  3510 
  3511 *** ZF ***
  3512 
  3513 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3514 including the First Isomorphism Theorem (on quotienting by the kernel
  3515 of a homomorphism).
  3516 
  3517 * ZF/Simplifier: install second copy of type solver that actually
  3518 makes use of TC rules declared to Isar proof contexts (or locales);
  3519 the old version is still required for ML proof scripts.
  3520 
  3521 
  3522 *** Cube ***
  3523 
  3524 * Converted to Isar theory format; use locales instead of axiomatic
  3525 theories.
  3526 
  3527 
  3528 *** ML ***
  3529 
  3530 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3531 for ||>, ||>>, |>>,
  3532 
  3533 * Pure/library.ML no longer defines its own option datatype, but uses
  3534 that of the SML basis, which has constructors NONE and SOME instead of
  3535 None and Some, as well as exception Option.Option instead of OPTION.
  3536 The functions the, if_none, is_some, is_none have been adapted
  3537 accordingly, while Option.map replaces apsome.
  3538 
  3539 * Pure/library.ML: the exception LIST has been given up in favour of
  3540 the standard exceptions Empty and Subscript, as well as
  3541 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3542 superceded by the standard hd and tl functions etc.
  3543 
  3544 A number of basic list functions are no longer exported to the ML
  3545 toplevel, as they are variants of predefined functions.  The following
  3546 suggests how one can translate existing code:
  3547 
  3548     rev_append xs ys = List.revAppend (xs, ys)
  3549     nth_elem (i, xs) = List.nth (xs, i)
  3550     last_elem xs = List.last xs
  3551     flat xss = List.concat xss
  3552     seq fs = List.app fs
  3553     partition P xs = List.partition P xs
  3554     mapfilter f xs = List.mapPartial f xs
  3555 
  3556 * Pure/library.ML: several combinators for linear functional
  3557 transformations, notably reverse application and composition:
  3558 
  3559   x |> f                f #> g
  3560   (x, y) |-> f          f #-> g
  3561 
  3562 * Pure/library.ML: introduced/changed precedence of infix operators:
  3563 
  3564   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3565   infix 2 ?;
  3566   infix 3 o oo ooo oooo;
  3567   infix 4 ~~ upto downto;
  3568 
  3569 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3570 infix operators.
  3571 
  3572 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3573 fold_map support linear functional transformations and nesting.  For
  3574 example:
  3575 
  3576   fold f [x1, ..., xN] y =
  3577     y |> f x1 |> ... |> f xN
  3578 
  3579   (fold o fold) f [xs1, ..., xsN] y =
  3580     y |> fold f xs1 |> ... |> fold f xsN
  3581 
  3582   fold f [x1, ..., xN] =
  3583     f x1 #> ... #> f xN
  3584 
  3585   (fold o fold) f [xs1, ..., xsN] =
  3586     fold f xs1 #> ... #> fold f xsN
  3587 
  3588 * Pure/library.ML: the following selectors on type 'a option are
  3589 available:
  3590 
  3591   the:               'a option -> 'a  (*partial*)
  3592   these:             'a option -> 'a  where 'a = 'b list
  3593   the_default: 'a -> 'a option -> 'a
  3594   the_list:          'a option -> 'a list
  3595 
  3596 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3597 basic operations for association lists, following natural argument
  3598 order; moreover the explicit equality predicate passed here avoids
  3599 potentially expensive polymorphic runtime equality checks.
  3600 The old functions may be expressed as follows:
  3601 
  3602   assoc = uncurry (AList.lookup (op =))
  3603   assocs = these oo AList.lookup (op =)
  3604   overwrite = uncurry (AList.update (op =)) o swap
  3605 
  3606 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3607 
  3608   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3609   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3610 
  3611 replacing make_keylist and keyfilter (occassionally used)
  3612 Naive rewrites:
  3613 
  3614   make_keylist = AList.make
  3615   keyfilter = AList.find (op =)
  3616 
  3617 * eq_fst and eq_snd now take explicit equality parameter, thus
  3618   avoiding eqtypes. Naive rewrites:
  3619 
  3620     eq_fst = eq_fst (op =)
  3621     eq_snd = eq_snd (op =)
  3622 
  3623 * Removed deprecated apl and apr (rarely used).
  3624   Naive rewrites:
  3625 
  3626     apl (n, op) =>>= curry op n
  3627     apr (op, m) =>>= fn n => op (n, m)
  3628 
  3629 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3630 provides a reasonably efficient light-weight implementation of sets as
  3631 lists.
  3632 
  3633 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3634 few new operations; existing lookup and update are now curried to
  3635 follow natural argument order (for use with fold etc.);
  3636 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3637 
  3638 * Pure/General: output via the Isabelle channels of
  3639 writeln/warning/error etc. is now passed through Output.output, with a
  3640 hook for arbitrary transformations depending on the print_mode
  3641 (cf. Output.add_mode -- the first active mode that provides a output
  3642 function wins).  Already formatted output may be embedded into further
  3643 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3644 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3645 accommodate easy composition of diagnostic messages etc.  Programmers
  3646 rarely need to care about Output.output or Output.raw at all, with
  3647 some notable exceptions: Output.output is required when bypassing the
  3648 standard channels (writeln etc.), or in token translations to produce
  3649 properly formatted results; Output.raw is required when capturing
  3650 already output material that will eventually be presented to the user
  3651 a second time.  For the default print mode, both Output.output and
  3652 Output.raw have no effect.
  3653 
  3654 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3655 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3656 cumulative results are displayed at the end of a batch session.
  3657 
  3658 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3659 replaced by File.platform_path and File.shell_path (with appropriate
  3660 hooks).  This provides a clean interface for unusual systems where the
  3661 internal and external process view of file names are different.
  3662 
  3663 * Pure: more efficient orders for basic syntactic entities: added
  3664 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3665 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3666 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3667 orders now -- potential INCOMPATIBILITY for code that depends on a
  3668 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3669 Library.sort_strings on result).
  3670 
  3671 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3672 fold_types traverse types/terms from left to right, observing natural
  3673 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3674 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3675 
  3676 * Pure: name spaces have been refined, with significant changes of the
  3677 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3678 to extern(_table).  The plain name entry path is superceded by a
  3679 general 'naming' context, which also includes the 'policy' to produce
  3680 a fully qualified name and external accesses of a fully qualified
  3681 name; NameSpace.extend is superceded by context dependent
  3682 Sign.declare_name.  Several theory and proof context operations modify
  3683 the naming context.  Especially note Theory.restore_naming and
  3684 ProofContext.restore_naming to get back to a sane state; note that
  3685 Theory.add_path is no longer sufficient to recover from
  3686 Theory.absolute_path in particular.
  3687 
  3688 * Pure: new flags short_names (default false) and unique_names
  3689 (default true) for controlling output of qualified names.  If
  3690 short_names is set, names are printed unqualified.  If unique_names is
  3691 reset, the name prefix is reduced to the minimum required to achieve
  3692 the original result when interning again, even if there is an overlap
  3693 with earlier declarations.
  3694 
  3695 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3696 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3697 (useful for printing error messages).  INCOMPATIBILITY.
  3698 
  3699 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3700 Theory.theory are now identified, referring to the universal
  3701 Context.theory (see Pure/context.ML).  Actual signature and theory
  3702 content is managed as theory data.  The old code and interfaces were
  3703 spread over many files and structures; the new arrangement introduces
  3704 considerable INCOMPATIBILITY to gain more clarity:
  3705 
  3706   Context -- theory management operations (name, identity, inclusion,
  3707     parents, ancestors, merge, etc.), plus generic theory data;
  3708 
  3709   Sign -- logical signature and syntax operations (declaring consts,
  3710     types, etc.), plus certify/read for common entities;
  3711 
  3712   Theory -- logical theory operations (stating axioms, definitions,
  3713     oracles), plus a copy of logical signature operations (consts,
  3714     types, etc.); also a few basic management operations (Theory.copy,
  3715     Theory.merge, etc.)
  3716 
  3717 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3718 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3719 for convenience -- they merely return the theory.
  3720 
  3721 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3722 
  3723 * Pure: the Isar proof context type is already defined early in Pure
  3724 as Context.proof (note that ProofContext.context and Proof.context are
  3725 aliases, where the latter is the preferred name).  This enables other
  3726 Isabelle components to refer to that type even before Isar is present.
  3727 
  3728 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3729 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3730 any of these kinds.  For example, Sign.intern typeK is now
  3731 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3732 Theory.hide_types.  Also note that former
  3733 Theory.hide_classes/types/consts are now
  3734 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3735 internalize their arguments!  INCOMPATIBILITY.
  3736 
  3737 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3738 datatype thmref (with constructors Name and NameSelection) instead of
  3739 plain string -- INCOMPATIBILITY;
  3740 
  3741 * Pure: cases produced by proof methods specify options, where NONE
  3742 means to remove case bindings -- INCOMPATIBILITY in
  3743 (RAW_)METHOD_CASES.
  3744 
  3745 * Pure: the following operations retrieve axioms or theorems from a
  3746 theory node or theory hierarchy, respectively:
  3747 
  3748   Theory.axioms_of: theory -> (string * term) list
  3749   Theory.all_axioms_of: theory -> (string * term) list
  3750   PureThy.thms_of: theory -> (string * thm) list
  3751   PureThy.all_thms_of: theory -> (string * thm) list
  3752 
  3753 * Pure: print_tac now outputs the goal through the trace channel.
  3754 
  3755 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3756 Reference Toplevel.debug (default false) controls detailed printing
  3757 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3758 controls execution profiling -- set to 1 for time and 2 for space
  3759 (both increase the runtime).
  3760 
  3761 * Isar session: The initial use of ROOT.ML is now always timed,
  3762 i.e. the log will show the actual process times, in contrast to the
  3763 elapsed wall-clock time that the outer shell wrapper produces.
  3764 
  3765 * Simplifier: improved handling of bound variables (nameless
  3766 representation, avoid allocating new strings).  Simprocs that invoke
  3767 the Simplifier recursively should use Simplifier.inherit_bounds to
  3768 avoid local name clashes.  Failure to do so produces warnings
  3769 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3770 for further details.
  3771 
  3772 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3773 bindings for all theorems stored within a given theory; this may help
  3774 in porting non-Isar theories to Isar ones, while keeping ML proof
  3775 scripts for the time being.
  3776 
  3777 * ML operator HTML.with_charset specifies the charset begin used for
  3778 generated HTML files.  For example:
  3779 
  3780   HTML.with_charset "utf-8" use_thy "Hebrew";
  3781   HTML.with_charset "utf-8" use_thy "Chinese";
  3782 
  3783 
  3784 *** System ***
  3785 
  3786 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3787 isabelle, isatool etc.).
  3788 
  3789 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3790 isatool doc, isatool mkdir, display_drafts etc.).
  3791 
  3792 * isatool usedir: option -f allows specification of the ML file to be
  3793 used by Isabelle; default is ROOT.ML.
  3794 
  3795 * New isatool version outputs the version identifier of the Isabelle
  3796 distribution being used.
  3797 
  3798 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3799 (containing Boolean satisfiability problems) into Isabelle/HOL
  3800 theories.
  3801 
  3802 
  3803 
  3804 New in Isabelle2004 (April 2004)
  3805 --------------------------------
  3806 
  3807 *** General ***
  3808 
  3809 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3810   Replaces linorder.ML.
  3811 
  3812 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3813   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3814   (\<a>...\<z>), are now considered normal letters, and can therefore
  3815   be used anywhere where an ASCII letter (a...zA...Z) has until
  3816   now. COMPATIBILITY: This obviously changes the parsing of some
  3817   terms, especially where a symbol has been used as a binder, say
  3818   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3819   as an identifier.  Fix it by inserting a space around former
  3820   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3821   existing theory and ML files.
  3822 
  3823 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3824 
  3825 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3826   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3827   a normal (but invisible) letter. For multiple letter subscripts repeat
  3828   \<^isub> like this: x\<^isub>1\<^isub>2.
  3829 
  3830 * Pure: There are now sub-/superscripts that can span more than one
  3831   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3832   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3833   superscript. The new control characters are not identifier parts.
  3834 
  3835 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3836   content of "..." to the latex file instead of \isacntrl... . The "..."
  3837   may consist of any printable characters excluding the end bracket >.
  3838 
  3839 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3840   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3841   declare constants "final", which prevents their being given a definition
  3842   later.  It is useful for constants whose behaviour is fixed axiomatically
  3843   rather than definitionally, such as the meta-logic connectives.
  3844 
  3845 * Pure: 'instance' now handles general arities with general sorts
  3846   (i.e. intersections of classes),
  3847 
  3848 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3849   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3850   It can be changed to alter the colors/layout of generated pages.
  3851 
  3852 
  3853 *** Isar ***
  3854 
  3855 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3856   cut_tac, subgoal_tac and thin_tac:
  3857   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3858     locales are no longer forced to write Isar proof scripts.
  3859     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3860     emulations.
  3861   - INCOMPATIBILITY: names of variables to be instantiated may no
  3862     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3863     This is consistent with the instantiation attribute "where".
  3864 
  3865 * Attributes "where" and "of":
  3866   - Now take type variables of instantiated theorem into account when reading
  3867     the instantiation string.  This fixes a bug that caused instantiated
  3868     theorems to have too special types in some circumstances.
  3869   - "where" permits explicit instantiations of type variables.
  3870 
  3871 * Calculation commands "moreover" and "also" no longer interfere with
  3872   current facts ("this"), admitting arbitrary combinations with "then"
  3873   and derived forms.
  3874 
  3875 * Locales:
  3876   - Goal statements involving the context element "includes" no longer
  3877     generate theorems with internal delta predicates (those ending on
  3878     "_axioms") in the premise.
  3879     Resolve particular premise with <locale>.intro to obtain old form.
  3880   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3881     specification and "includes" elements in goal statement.
  3882   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3883     [intro?] and [elim?] (respectively) by default.
  3884   - Experimental command for instantiation of locales in proof contexts:
  3885         instantiate <label>[<attrs>]: <loc>
  3886     Instantiates locale <loc> and adds all its theorems to the current context
  3887     taking into account their attributes.  Label and attrs are optional
  3888     modifiers, like in theorem declarations.  If present, names of
  3889     instantiated theorems are qualified with <label>, and the attributes
  3890     <attrs> are applied after any attributes these theorems might have already.
  3891       If the locale has assumptions, a chained fact of the form
  3892     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3893     are derived.  The command does not support old-style locales declared
  3894     with "locale (open)".
  3895       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3896 
  3897 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3898   (Isar) contexts.
  3899 
  3900 
  3901 *** HOL ***
  3902 
  3903 * Proof import: new image HOL4 contains the imported library from
  3904   the HOL4 system with about 2500 theorems. It is imported by
  3905   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3906   can be used like any other Isabelle image.  See
  3907   HOL/Import/HOL/README for more information.
  3908 
  3909 * Simplifier:
  3910   - Much improved handling of linear and partial orders.
  3911     Reasoners for linear and partial orders are set up for type classes
  3912     "linorder" and "order" respectively, and are added to the default simpset
  3913     as solvers.  This means that the simplifier can build transitivity chains
  3914     to solve goals from the assumptions.
  3915   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3916     of blast or auto after simplification become unnecessary because the goal
  3917     is solved by simplification already.
  3918 
  3919 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3920     all proved in axiomatic type classes for semirings, rings and fields.
  3921 
  3922 * Numerics:
  3923   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3924     now formalized using the Ring_and_Field theory mentioned above.
  3925   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3926     than before, because now they are set up once in a generic manner.
  3927   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3928     Look for the general versions in Ring_and_Field (and Power if they concern
  3929     exponentiation).
  3930 
  3931 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3932 
  3933 * Records:
  3934   - Record types are now by default printed with their type abbreviation
  3935     instead of the list of all field types. This can be configured via
  3936     the reference "print_record_type_abbr".
  3937   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3938     (not enabled by default).
  3939   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3940     EX x. x = sel r to True (not enabled by default).
  3941   - Tactic "record_split_simp_tac" to split and simplify records added.
  3942 
  3943 * 'specification' command added, allowing for definition by
  3944   specification.  There is also an 'ax_specification' command that
  3945   introduces the new constants axiomatically.
  3946 
  3947 * arith(_tac) is now able to generate counterexamples for reals as well.
  3948 
  3949 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3950 
  3951 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3952   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3953 
  3954 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3955   matrix theory to linear programming.
  3956 
  3957 * Unions and Intersections:
  3958   The latex output syntax of UN and INT has been changed
  3959   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3960   i.e. the index formulae has become a subscript.
  3961   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3962 
  3963 * Unions and Intersections over Intervals:
  3964   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3965   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3966   like in normal math, and corresponding versions for < and for intersection.
  3967 
  3968 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3969   lexicographic dictonary ordering has been added as "lexord".
  3970 
  3971 * ML: the legacy theory structures Int and List have been removed. They had
  3972   conflicted with ML Basis Library structures having the same names.
  3973 
  3974 * 'refute' command added to search for (finite) countermodels.  Only works
  3975   for a fragment of HOL.  The installation of an external SAT solver is
  3976   highly recommended.  See "HOL/Refute.thy" for details.
  3977 
  3978 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3979   formulae under an assignment of free variables to random values.
  3980   In contrast to 'refute', it can deal with inductive datatypes,
  3981   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3982   for examples.
  3983 
  3984 
  3985 *** HOLCF ***
  3986 
  3987 * Streams now come with concatenation and are part of the HOLCF image
  3988 
  3989 
  3990 
  3991 New in Isabelle2003 (May 2003)
  3992 ------------------------------
  3993 
  3994 *** General ***
  3995 
  3996 * Provers/simplifier:
  3997 
  3998   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3999     Assumptions are now subject to complete mutual simplification,
  4000     not just from left to right. The simplifier now preserves
  4001     the order of assumptions.
  4002 
  4003     Potential INCOMPATIBILITY:
  4004 
  4005     -- simp sometimes diverges where the old version did
  4006        not, e.g. invoking simp on the goal
  4007 
  4008         [| P (f x); y = x; f x = f y |] ==> Q
  4009 
  4010        now gives rise to the infinite reduction sequence
  4011 
  4012         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4013 
  4014        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4015        kind of problem.
  4016 
  4017     -- Tactics combining classical reasoner and simplification (such as auto)
  4018        are also affected by this change, because many of them rely on
  4019        simp. They may sometimes diverge as well or yield a different numbers
  4020        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4021        in case of problems. Sometimes subsequent calls to the classical
  4022        reasoner will fail because a preceeding call to the simplifier too
  4023        eagerly simplified the goal, e.g. deleted redundant premises.
  4024 
  4025   - The simplifier trace now shows the names of the applied rewrite rules
  4026 
  4027   - You can limit the number of recursive invocations of the simplifier
  4028     during conditional rewriting (where the simplifie tries to solve the
  4029     conditions before applying the rewrite rule):
  4030     ML "simp_depth_limit := n"
  4031     where n is an integer. Thus you can force termination where previously
  4032     the simplifier would diverge.
  4033 
  4034   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4035 
  4036   - No longer aborts on failed congruence proof.  Instead, the
  4037     congruence is ignored.
  4038 
  4039 * Pure: New generic framework for extracting programs from constructive
  4040   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4041   as HOL/Extraction for some case studies.
  4042 
  4043 * Pure: The main goal of the proof state is no longer shown by default, only
  4044 the subgoals. This behaviour is controlled by a new flag.
  4045    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4046 (ML: Proof.show_main_goal).
  4047 
  4048 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4049 rules whose conclusion matches subgoal 1:
  4050       PG menu: Isabelle/Isar -> Show me -> matching rules
  4051 The rules are ordered by how closely they match the subgoal.
  4052 In particular, rules that solve a subgoal outright are displayed first
  4053 (or rather last, the way they are printed).
  4054 (ML: ProofGeneral.print_intros())
  4055 
  4056 * Pure: New flag trace_unify_fail causes unification to print
  4057 diagnostic information (PG: in trace buffer) when it fails. This is
  4058 useful for figuring out why single step proofs like rule, erule or
  4059 assumption failed.
  4060 
  4061 * Pure: Locale specifications now produce predicate definitions
  4062 according to the body of text (covering assumptions modulo local
  4063 definitions); predicate "loc_axioms" covers newly introduced text,
  4064 while "loc" is cumulative wrt. all included locale expressions; the
  4065 latter view is presented only on export into the global theory
  4066 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4067 on the old view without predicates;
  4068 
  4069 * Pure: predefined locales "var" and "struct" are useful for sharing
  4070 parameters (as in CASL, for example); just specify something like
  4071 ``var x + var y + struct M'' as import;
  4072 
  4073 * Pure: improved thms_containing: proper indexing of facts instead of
  4074 raw theorems; check validity of results wrt. current name space;
  4075 include local facts of proof configuration (also covers active
  4076 locales), cover fixed variables in index; may use "_" in term
  4077 specification; an optional limit for the number of printed facts may
  4078 be given (the default is 40);
  4079 
  4080 * Pure: disallow duplicate fact bindings within new-style theory files
  4081 (batch-mode only);
  4082 
  4083 * Provers: improved induct method: assumptions introduced by case
  4084 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4085 the goal statement); "foo" still refers to all facts collectively;
  4086 
  4087 * Provers: the function blast.overloaded has been removed: all constants
  4088 are regarded as potentially overloaded, which improves robustness in exchange
  4089 for slight decrease in efficiency;
  4090 
  4091 * Provers/linorder: New generic prover for transitivity reasoning over
  4092 linear orders.  Note: this prover is not efficient!
  4093 
  4094 * Isar: preview of problems to finish 'show' now produce an error
  4095 rather than just a warning (in interactive mode);
  4096 
  4097 
  4098 *** HOL ***
  4099 
  4100 * arith(_tac)
  4101 
  4102  - Produces a counter example if it cannot prove a goal.
  4103    Note that the counter example may be spurious if the goal is not a formula
  4104    of quantifier-free linear arithmetic.
  4105    In ProofGeneral the counter example appears in the trace buffer.
  4106 
  4107  - Knows about div k and mod k where k is a numeral of type nat or int.
  4108 
  4109  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4110    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4111    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4112 
  4113 * simp's arithmetic capabilities have been enhanced a bit: it now
  4114 takes ~= in premises into account (by performing a case split);
  4115 
  4116 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4117 are distributed over a sum of terms;
  4118 
  4119 * New tactic "trans_tac" and method "trans" instantiate
  4120 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4121 "<=", "<" and "=").
  4122 
  4123 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4124 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4125 
  4126 * 'typedef' command has new option "open" to suppress the set
  4127 definition;
  4128 
  4129 * functions Min and Max on finite sets have been introduced (theory
  4130 Finite_Set);
  4131 
  4132 * attribute [symmetric] now works for relations as well; it turns
  4133 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4134 
  4135 * induct over a !!-quantified statement (say !!x1..xn):
  4136   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4137 
  4138 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4139 %x. None. Warning: empty_def now refers to the previously hidden definition
  4140 of the empty set.
  4141 
  4142 * Algebra: formalization of classical algebra.  Intended as base for
  4143 any algebraic development in Isabelle.  Currently covers group theory
  4144 (up to Sylow's theorem) and ring theory (Universal Property of
  4145 Univariate Polynomials).  Contributions welcome;
  4146 
  4147 * GroupTheory: deleted, since its material has been moved to Algebra;
  4148 
  4149 * Complex: new directory of the complex numbers with numeric constants,
  4150 nonstandard complex numbers, and some complex analysis, standard and
  4151 nonstandard (Jacques Fleuriot);
  4152 
  4153 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4154 
  4155 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4156 Fleuriot);
  4157 
  4158 * Real/HahnBanach: updated and adapted to locales;
  4159 
  4160 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4161 Gray and Kramer);
  4162 
  4163 * UNITY: added the Meier-Sanders theory of progress sets;
  4164 
  4165 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4166 as abstract algorithms, instantiated to the JVM;
  4167 
  4168 * Bali: Java source language formalization. Type system, operational
  4169 semantics, axiomatic semantics. Supported language features:
  4170 classes, interfaces, objects,virtual methods, static methods,
  4171 static/instance fields, arrays, access modifiers, definite
  4172 assignment, exceptions.
  4173 
  4174 
  4175 *** ZF ***
  4176 
  4177 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4178 universe, etc.);
  4179 
  4180 * Main ZF: virtually all theories converted to new-style format;
  4181 
  4182 
  4183 *** ML ***
  4184 
  4185 * Pure: Tactic.prove provides sane interface for internal proofs;
  4186 omits the infamous "standard" operation, so this is more appropriate
  4187 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4188 
  4189 * Pure: improved error reporting of simprocs;
  4190 
  4191 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4192 up simprocs;
  4193 
  4194 
  4195 *** Document preparation ***
  4196 
  4197 * uses \par instead of \\ for line breaks in theory text. This may
  4198 shift some page breaks in large documents. To get the old behaviour
  4199 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4200 
  4201 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4202 other packages
  4203 
  4204 * \<euro> now needs package babel/greek instead of marvosym (which
  4205 broke \Rightarrow)
  4206 
  4207 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4208 textcomp package)
  4209 
  4210 
  4211 
  4212 New in Isabelle2002 (March 2002)
  4213 --------------------------------
  4214 
  4215 *** Document preparation ***
  4216 
  4217 * greatly simplified document preparation setup, including more
  4218 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4219 instructive isatool mkdir; users should basically be able to get
  4220 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4221 users may run a separate document processing stage manually like this:
  4222 "isatool usedir -D output HOL Test && isatool document Test/output";
  4223 
  4224 * theory dependency graph may now be incorporated into documents;
  4225 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4226 with \includegraphics of LaTeX;
  4227 
  4228 * proper spacing of consecutive markup elements, especially text
  4229 blocks after section headings;
  4230 
  4231 * support bold style (for single symbols only), input syntax is like
  4232 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4233 
  4234 * \<bullet> is now output as bold \cdot by default, which looks much
  4235 better in printed text;
  4236 
  4237 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4238 note that these symbols are currently unavailable in Proof General /
  4239 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4240 
  4241 * isatool latex no longer depends on changed TEXINPUTS, instead
  4242 isatool document copies the Isabelle style files to the target
  4243 location;
  4244 
  4245 
  4246 *** Isar ***
  4247 
  4248 * Pure/Provers: improved proof by cases and induction;
  4249   - 'case' command admits impromptu naming of parameters (such as
  4250     "case (Suc n)");
  4251   - 'induct' method divinates rule instantiation from the inductive
  4252     claim; no longer requires excessive ?P bindings for proper
  4253     instantiation of cases;
  4254   - 'induct' method properly enumerates all possibilities of set/type
  4255     rules; as a consequence facts may be also passed through *type*
  4256     rules without further ado;
  4257   - 'induct' method now derives symbolic cases from the *rulified*
  4258     rule (before it used to rulify cases stemming from the internal
  4259     atomized version); this means that the context of a non-atomic
  4260     statement becomes is included in the hypothesis, avoiding the
  4261     slightly cumbersome show "PROP ?case" form;
  4262   - 'induct' may now use elim-style induction rules without chaining
  4263     facts, using ``missing'' premises from the goal state; this allows
  4264     rules stemming from inductive sets to be applied in unstructured
  4265     scripts, while still benefitting from proper handling of non-atomic
  4266     statements; NB: major inductive premises need to be put first, all
  4267     the rest of the goal is passed through the induction;
  4268   - 'induct' proper support for mutual induction involving non-atomic
  4269     rule statements (uses the new concept of simultaneous goals, see
  4270     below);
  4271   - append all possible rule selections, but only use the first
  4272     success (no backtracking);
  4273   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4274   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4275   - added 'print_induct_rules' (covered by help item in recent Proof
  4276     General versions);
  4277   - moved induct/cases attributes to Pure, methods to Provers;
  4278   - generic method setup instantiated for FOL and HOL;
  4279 
  4280 * Pure: support multiple simultaneous goal statements, for example
  4281 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4282 meta-level mechanism, this acts as if several individual goals had
  4283 been stated separately; in particular common proof methods need to be
  4284 repeated in order to cover all claims; note that a single elimination
  4285 step is *not* sufficient to establish the two conjunctions, so this
  4286 fails:
  4287 
  4288   assume "A & B" then have A and B ..   (*".." fails*)
  4289 
  4290 better use "obtain" in situations as above; alternative refer to
  4291 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4292 
  4293 * Pure: proper integration with ``locales''; unlike the original
  4294 version by Florian Kammller, Isar locales package high-level proof
  4295 contexts rather than raw logical ones (e.g. we admit to include
  4296 attributes everywhere); operations on locales include merge and
  4297 rename; support for implicit arguments (``structures''); simultaneous
  4298 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4299 some examples;
  4300 
  4301 * Pure: the following commands have been ``localized'', supporting a
  4302 target locale specification "(in name)": 'lemma', 'theorem',
  4303 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4304 stored both within the locale and at the theory level (exported and
  4305 qualified by the locale name);
  4306 
  4307 * Pure: theory goals may now be specified in ``long'' form, with
  4308 ad-hoc contexts consisting of arbitrary locale elements. for example
  4309 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4310 definitions may be given, too); the result is a meta-level rule with
  4311 the context elements being discharged in the obvious way;
  4312 
  4313 * Pure: new proof command 'using' allows to augment currently used
  4314 facts after a goal statement ('using' is syntactically analogous to
  4315 'apply', but acts on the goal's facts only); this allows chained facts
  4316 to be separated into parts given before and after a claim, as in
  4317 ``from a and b have C using d and e <proof>'';
  4318 
  4319 * Pure: renamed "antecedent" case to "rule_context";
  4320 
  4321 * Pure: new 'judgment' command records explicit information about the
  4322 object-logic embedding (used by several tools internally); no longer
  4323 use hard-wired "Trueprop";
  4324 
  4325 * Pure: added 'corollary' command;
  4326 
  4327 * Pure: fixed 'token_translation' command;
  4328 
  4329 * Pure: removed obsolete 'exported' attribute;
  4330 
  4331 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4332 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4333 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4334 
  4335 * Pure: method 'atomize' presents local goal premises as object-level
  4336 statements (atomic meta-level propositions); setup controlled via
  4337 rewrite rules declarations of 'atomize' attribute; example
  4338 application: 'induct' method with proper rule statements in improper
  4339 proof *scripts*;
  4340 
  4341 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4342 now consider the syntactic context of assumptions, giving a better
  4343 chance to get type-inference of the arguments right (this is
  4344 especially important for locales);
  4345 
  4346 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4347 mode;
  4348 
  4349 * Pure/obtain: the formal conclusion "thesis", being marked as
  4350 ``internal'', may no longer be reference directly in the text;
  4351 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4352 situations;
  4353 
  4354 * Pure: generic 'sym' attribute which declares a rule both as pure
  4355 'elim?' and for the 'symmetric' operation;
  4356 
  4357 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4358 text; the fixed correlation with particular command syntax has been
  4359 discontinued;
  4360 
  4361 * Pure: new method 'rules' is particularly well-suited for proof
  4362 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4363 but often produces more compact proof terms with less detours;
  4364 
  4365 * Pure/Provers/classical: simplified integration with pure rule
  4366 attributes and methods; the classical "intro?/elim?/dest?"
  4367 declarations coincide with the pure ones; the "rule" method no longer
  4368 includes classically swapped intros; "intro" and "elim" methods no
  4369 longer pick rules from the context; also got rid of ML declarations
  4370 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4371 INCOMPATIBILITY;
  4372 
  4373 * Provers/classical: attribute 'swapped' produces classical inversions
  4374 of introduction rules;
  4375 
  4376 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4377 rules instead of full simplifier context; 'iff' attribute handles
  4378 conditional rules;
  4379 
  4380 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4381 
  4382 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4383 "(permissive)" option to recover old behavior;
  4384 
  4385 * HOL: 'inductive' no longer features separate (collective) attributes
  4386 for 'intros' (was found too confusing);
  4387 
  4388 * HOL: properly declared induction rules less_induct and
  4389 wf_induct_rule;
  4390 
  4391 
  4392 *** HOL ***
  4393 
  4394 * HOL: moved over to sane numeral syntax; the new policy is as
  4395 follows:
  4396 
  4397   - 0 and 1 are polymorphic constants, which are defined on any
  4398   numeric type (nat, int, real etc.);
  4399 
  4400   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4401   binary representation internally;
  4402 
  4403   - type nat has special constructor Suc, and generally prefers Suc 0
  4404   over 1::nat and Suc (Suc 0) over 2::nat;
  4405 
  4406 This change may cause significant problems of INCOMPATIBILITY; here
  4407 are some hints on converting existing sources:
  4408 
  4409   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4410   entities, so expressions involving "-" (unary or binary minus) need
  4411   to be spaced properly;
  4412 
  4413   - existing occurrences of "1" may need to be constraint "1::nat" or
  4414   even replaced by Suc 0; similar for old "2";
  4415 
  4416   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4417 
  4418   - remove all special provisions on numerals in proofs;
  4419 
  4420 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4421 representation (depends on bin_arith_simps in the default context);
  4422 
  4423 * HOL: symbolic syntax for x^2 (numeral 2);
  4424 
  4425 * HOL: the class of all HOL types is now called "type" rather than
  4426 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4427 in axclass/classes, instance/arities, and (usually rare) occurrences
  4428 in typings (of consts etc.); internally the class is called
  4429 "HOL.type", ML programs should refer to HOLogic.typeS;
  4430 
  4431 * HOL/record package improvements:
  4432   - new derived operations "fields" to build a partial record section,
  4433     "extend" to promote a fixed record to a record scheme, and
  4434     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4435     declared as simp by default;
  4436   - shared operations ("more", "fields", etc.) now need to be always
  4437     qualified) --- potential INCOMPATIBILITY;
  4438   - removed "make_scheme" operations (use "make" with "extend") --
  4439     INCOMPATIBILITY;
  4440   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4441   - provides cases/induct rules for use with corresponding Isar
  4442     methods (for concrete records, record schemes, concrete more
  4443     parts, and schematic more parts -- in that order);
  4444   - internal definitions directly based on a light-weight abstract
  4445     theory of product types over typedef rather than datatype;
  4446 
  4447 * HOL: generic code generator for generating executable ML code from
  4448 specifications; specific support for HOL constructs such as inductive
  4449 datatypes and sets, as well as recursive functions; can be invoked
  4450 via 'generate_code' theory section;
  4451 
  4452 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4453 
  4454 * HOL: consolidated and renamed several theories.  In particular:
  4455         Ord.thy has been absorbed into HOL.thy
  4456         String.thy has been absorbed into List.thy
  4457 
  4458 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4459 (beware of argument permutation!);
  4460 
  4461 * HOL: linorder_less_split superseded by linorder_cases;
  4462 
  4463 * HOL/List: "nodups" renamed to "distinct";
  4464 
  4465 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4466 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4467   - Ex_def has changed, now need to use some_eq_ex
  4468 
  4469 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4470 in this (rare) case use:
  4471 
  4472   delSWrapper "split_all_tac"
  4473   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4474 
  4475 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4476 MAY FAIL;
  4477 
  4478 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4479 Isabelle's type classes, ^ on functions and relations has too general
  4480 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4481 necessary to attach explicit type constraints;
  4482 
  4483 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4484 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4485 renamed accordingly (eg "compI" -> "rel_compI").
  4486 
  4487 * HOL: syntax translations now work properly with numerals and records
  4488 expressions;
  4489 
  4490 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4491 of "lam" -- INCOMPATIBILITY;
  4492 
  4493 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4494 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4495 renamed "Product_Type.unit";
  4496 
  4497 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4498 
  4499 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4500 the "cases" method);
  4501 
  4502 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4503 Florian Kammller);
  4504 
  4505 * HOL/IMP: updated and converted to new-style theory format; several
  4506 parts turned into readable document, with proper Isar proof texts and
  4507 some explanations (by Gerwin Klein);
  4508 
  4509 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4510 
  4511 * HOL-Hyperreal is now a logic image;
  4512 
  4513 
  4514 *** HOLCF ***
  4515 
  4516 * Isar: consts/constdefs supports mixfix syntax for continuous
  4517 operations;
  4518 
  4519 * Isar: domain package adapted to new-style theory format, e.g. see
  4520 HOLCF/ex/Dnat.thy;
  4521 
  4522 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4523 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4524 lift.induct_tac, always use UU instead of Undef;
  4525 
  4526 * HOLCF/IMP: updated and converted to new-style theory;
  4527 
  4528 
  4529 *** ZF ***
  4530 
  4531 * Isar: proper integration of logic-specific tools and packages,
  4532 including theory commands '(co)inductive', '(co)datatype',
  4533 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4534 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4535 
  4536 * theory Main no longer includes AC; for the Axiom of Choice, base
  4537 your theory on Main_ZFC;
  4538 
  4539 * the integer library now covers quotients and remainders, with many
  4540 laws relating division to addition, multiplication, etc.;
  4541 
  4542 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4543 typeless version of the formalism;
  4544 
  4545 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4546 format;
  4547 
  4548 * ZF/Induct: new directory for examples of inductive definitions,
  4549 including theory Multiset for multiset orderings; converted to
  4550 new-style theory format;
  4551 
  4552 * ZF: many new theorems about lists, ordinals, etc.;
  4553 
  4554 
  4555 *** General ***
  4556 
  4557 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4558 variable proof controls level of detail: 0 = no proofs (only oracle
  4559 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4560 also ref manual for further ML interfaces;
  4561 
  4562 * Pure/axclass: removed obsolete ML interface
  4563 goal_subclass/goal_arity;
  4564 
  4565 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4566 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4567 separate tokens, so expressions involving minus need to be spaced
  4568 properly;
  4569 
  4570 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4571 rather than "infixl" or "infixr";
  4572 
  4573 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4574 sort constraint specifications in type inference; e.g. "x::_::foo"
  4575 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4576 type variable);
  4577 
  4578 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4579 control output of nested => (types); the default behavior is
  4580 "type_brackets";
  4581 
  4582 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4583 tokens into AST constants;
  4584 
  4585 * Pure/syntax: prefer later declarations of translations and print
  4586 translation functions; potential INCOMPATIBILITY: need to reverse
  4587 multiple declarations for same syntax element constant;
  4588 
  4589 * Pure/show_hyps reset by default (in accordance to existing Isar
  4590 practice);
  4591 
  4592 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4593 addSafter;
  4594 
  4595 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4596 as well;
  4597 
  4598 * system: tested support for MacOS X; should be able to get Isabelle +
  4599 Proof General to work in a plain Terminal after installing Poly/ML
  4600 (e.g. from the Isabelle distribution area) and GNU bash alone
  4601 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4602 support requires further installations, e.g. from
  4603 http://fink.sourceforge.net/);
  4604 
  4605 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4606 
  4607 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4608 of 40 MB), cf. ML_OPTIONS;
  4609 
  4610 * system: Proof General keywords specification is now part of the
  4611 Isabelle distribution (see etc/isar-keywords.el);
  4612 
  4613 * system: support for persistent Proof General sessions (refrain from
  4614 outdating all loaded theories on startup); user may create writable
  4615 logic images like this: ``isabelle -q HOL Test'';
  4616 
  4617 * system: smart selection of Isabelle process versus Isabelle
  4618 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4619 run both "isabelle" and "Isabelle" even if file names are badly
  4620 damaged (executable inspects the case of the first letter of its own
  4621 name); added separate "isabelle-process" and "isabelle-interface";
  4622 
  4623 * system: refrain from any attempt at filtering input streams; no
  4624 longer support ``8bit'' encoding of old isabelle font, instead proper
  4625 iso-latin characters may now be used; the related isatools
  4626 "symbolinput" and "nonascii" have disappeared as well;
  4627 
  4628 * system: removed old "xterm" interface (the print modes "xterm" and
  4629 "xterm_color" are still available for direct use in a suitable
  4630 terminal);
  4631 
  4632 
  4633 
  4634 New in Isabelle99-2 (February 2001)
  4635 -----------------------------------
  4636 
  4637 *** Overview of INCOMPATIBILITIES ***
  4638 
  4639 * HOL: please note that theories in the Library and elsewhere often use the
  4640 new-style (Isar) format; to refer to their theorems in an ML script you must
  4641 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4642 
  4643 * HOL: inductive package no longer splits induction rule aggressively,
  4644 but only as far as specified by the introductions given; the old
  4645 format may be recovered via ML function complete_split_rule or attribute
  4646 'split_rule (complete)';
  4647 
  4648 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4649 gfp_Tarski to gfp_unfold;
  4650 
  4651 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4652 
  4653 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4654 relation); infix "^^" has been renamed "``"; infix "``" has been
  4655 renamed "`"; "univalent" has been renamed "single_valued";
  4656 
  4657 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4658 operation;
  4659 
  4660 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4661 
  4662 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4663 
  4664 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4665 consequence, it is no longer monotonic wrt. the local goal context
  4666 (which is now passed through the inductive cases);
  4667 
  4668 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4669 \<gg> to \<ggreater>;
  4670 
  4671 
  4672 *** Document preparation ***
  4673 
  4674 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4675 available: are "it" for near math-mode best-style output, "sl" for
  4676 slanted text style, and "tt" for plain type-writer; if no
  4677 \isabellestyle command is given, output is according to slanted
  4678 type-writer);
  4679 
  4680 * support sub/super scripts (for single symbols only), input syntax is
  4681 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4682 
  4683 * some more standard symbols; see Appendix A of the system manual for
  4684 the complete list of symbols defined in isabellesym.sty;
  4685 
  4686 * improved isabelle style files; more abstract symbol implementation
  4687 (should now use \isamath{...} and \isatext{...} in custom symbol
  4688 definitions);
  4689 
  4690 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4691 state; Note that presentation of goal states does not conform to
  4692 actual human-readable proof documents.  Please do not include goal
  4693 states into document output unless you really know what you are doing!
  4694 
  4695 * proper indentation of antiquoted output with proportional LaTeX
  4696 fonts;
  4697 
  4698 * no_document ML operator temporarily disables LaTeX document
  4699 generation;
  4700 
  4701 * isatool unsymbolize tunes sources for plain ASCII communication;
  4702 
  4703 
  4704 *** Isar ***
  4705 
  4706 * Pure: Isar now suffers initial goal statements to contain unbound
  4707 schematic variables (this does not conform to actual readable proof
  4708 documents, due to unpredictable outcome and non-compositional proof
  4709 checking); users who know what they are doing may use schematic goals
  4710 for Prolog-style synthesis of proven results;
  4711 
  4712 * Pure: assumption method (an implicit finishing) now handles actual
  4713 rules as well;
  4714 
  4715 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4716 initial goal, declare "that" only as Pure intro (only for single
  4717 steps); the "that" rule assumption may now be involved in implicit
  4718 finishing, thus ".." becomes a feasible for trivial obtains;
  4719 
  4720 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4721 instance proofs may be performed by "..";
  4722 
  4723 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4724 statements as well;
  4725 
  4726 * Pure: more robust selection of calculational rules;
  4727 
  4728 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4729 rule (as well as the assumption rule);
  4730 
  4731 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4732 lemmas, using the graph browser tool;
  4733 
  4734 * Pure: predict failure of "show" in interactive mode;
  4735 
  4736 * Pure: 'thms_containing' now takes actual terms as arguments;
  4737 
  4738 * HOL: improved method 'induct' --- now handles non-atomic goals
  4739 (potential INCOMPATIBILITY); tuned error handling;
  4740 
  4741 * HOL: cases and induct rules now provide explicit hints about the
  4742 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4743 any remaining facts are inserted into the goal verbatim;
  4744 
  4745 * HOL: local contexts (aka cases) may now contain term bindings as
  4746 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4747 the result to be shown in each case;
  4748 
  4749 * HOL: added 'recdef_tc' command;
  4750 
  4751 * isatool convert assists in eliminating legacy ML scripts;
  4752 
  4753 
  4754 *** HOL ***
  4755 
  4756 * HOL/Library: a collection of generic theories to be used together
  4757 with main HOL; the theory loader path already includes this directory
  4758 by default; the following existing theories have been moved here:
  4759 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4760 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4761 
  4762 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4763 modelling and verification task performed in Isabelle/HOL +
  4764 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4765 
  4766 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4767 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4768 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4769 'domain', this makes the theory consistent with mathematical
  4770 literature;
  4771 
  4772 * HOL basics: added overloaded operations "inverse" and "divide"
  4773 (infix "/"), syntax for generic "abs" operation, generic summation
  4774 operator \<Sum>;
  4775 
  4776 * HOL/typedef: simplified package, provide more useful rules (see also
  4777 HOL/subset.thy);
  4778 
  4779 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4780 now expressed as a proper nested rule (old-style tactic scripts may
  4781 require atomize_strip_tac to cope with non-atomic premises);
  4782 
  4783 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4784 to "split_conv" (old name still available for compatibility);
  4785 
  4786 * HOL: improved concrete syntax for strings (e.g. allows translation
  4787 rules with string literals);
  4788 
  4789 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4790  and Fleuriot's mechanization of analysis, including the transcendental
  4791  functions for the reals;
  4792 
  4793 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4794 
  4795 
  4796 *** CTT ***
  4797 
  4798 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4799 "lam" is displayed as TWO lambda-symbols
  4800 
  4801 * CTT: theory Main now available, containing everything (that is, Bool
  4802 and Arith);
  4803 
  4804 
  4805 *** General ***
  4806 
  4807 * Pure: the Simplifier has been implemented properly as a derived rule
  4808 outside of the actual kernel (at last!); the overall performance
  4809 penalty in practical applications is about 50%, while reliability of
  4810 the Isabelle inference kernel has been greatly improved;
  4811 
  4812 * print modes "brackets" and "no_brackets" control output of nested =>
  4813 (types) and ==> (props); the default behaviour is "brackets";
  4814 
  4815 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4816 as assumptions as well;
  4817 
  4818 * system: support Poly/ML 4.0;
  4819 
  4820 * system: isatool install handles KDE version 1 or 2;
  4821 
  4822 
  4823 
  4824 New in Isabelle99-1 (October 2000)
  4825 ----------------------------------
  4826 
  4827 *** Overview of INCOMPATIBILITIES ***
  4828 
  4829 * HOL: simplification of natural numbers is much changed; to partly
  4830 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4831 issue the following ML commands:
  4832 
  4833   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4834   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4835 
  4836 * HOL: simplification no longer dives into case-expressions; this is
  4837 controlled by "t.weak_case_cong" for each datatype t;
  4838 
  4839 * HOL: nat_less_induct renamed to less_induct;
  4840 
  4841 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4842 fixsome to patch .thy and .ML sources automatically;
  4843 
  4844   select_equality  -> some_equality
  4845   select_eq_Ex     -> some_eq_ex
  4846   selectI2EX       -> someI2_ex
  4847   selectI2         -> someI2
  4848   selectI          -> someI
  4849   select1_equality -> some1_equality
  4850   Eps_sym_eq       -> some_sym_eq_trivial
  4851   Eps_eq           -> some_eq_trivial
  4852 
  4853 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4854 
  4855 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4856 instead);
  4857 
  4858 * HOL: the recursion equations generated by 'recdef' are now called
  4859 f.simps instead of f.rules;
  4860 
  4861 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4862 
  4863 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4864 sometimes be needed;
  4865 
  4866 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4867 
  4868 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4869 
  4870 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4871 product is now "<*>" instead of "Times"; the lexicographic product is
  4872 now "<*lex*>" instead of "**";
  4873 
  4874 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4875 of main HOL, but was unused); better use HOL's datatype package;
  4876 
  4877 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4878 the old syntax may be recovered as follows:
  4879 
  4880   syntax (symbols)
  4881     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4882       (infixl "\\<oplus>" 100)
  4883 
  4884 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4885 
  4886 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4887 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4888 internally;
  4889 
  4890 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4891 changed from A/r to A//r;
  4892 
  4893 * ZF: new treatment of arithmetic (nat & int) may break some old
  4894 proofs;
  4895 
  4896 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4897 rulify -> rule_format, elimify -> elim_format, ...);
  4898 
  4899 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4900 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4901 should have to change intro!! to intro? only); replaced "delrule" by
  4902 "rule del";
  4903 
  4904 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4905 
  4906 * Provers: strengthened force_tac by using new first_best_tac;
  4907 
  4908 * LaTeX document preparation: several changes of isabelle.sty (see
  4909 lib/texinputs);
  4910 
  4911 
  4912 *** Document preparation ***
  4913 
  4914 * formal comments (text blocks etc.) in new-style theories may now
  4915 contain antiquotations of thm/prop/term/typ/text to be presented
  4916 according to latex print mode; concrete syntax is like this:
  4917 @{term[show_types] "f(x) = a + x"};
  4918 
  4919 * isatool mkdir provides easy setup of Isabelle session directories,
  4920 including proper document sources;
  4921 
  4922 * generated LaTeX sources are now deleted after successful run
  4923 (isatool document -c); may retain a copy somewhere else via -D option
  4924 of isatool usedir;
  4925 
  4926 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4927 style files, achieving self-contained LaTeX sources and simplifying
  4928 LaTeX debugging;
  4929 
  4930 * old-style theories now produce (crude) LaTeX output as well;
  4931 
  4932 * browser info session directories are now self-contained (may be put
  4933 on WWW server seperately); improved graphs of nested sessions; removed
  4934 graph for 'all sessions';
  4935 
  4936 * several improvements in isabelle style files; \isabellestyle{it}
  4937 produces fake math mode output; \isamarkupheader is now \section by
  4938 default; see lib/texinputs/isabelle.sty etc.;
  4939 
  4940 
  4941 *** Isar ***
  4942 
  4943 * Isar/Pure: local results and corresponding term bindings are now
  4944 subject to Hindley-Milner polymorphism (similar to ML); this
  4945 accommodates incremental type-inference very nicely;
  4946 
  4947 * Isar/Pure: new derived language element 'obtain' supports
  4948 generalized existence reasoning;
  4949 
  4950 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4951 support accumulation of results, without applying any rules yet;
  4952 useful to collect intermediate results without explicit name
  4953 references, and for use with transitivity rules with more than 2
  4954 premises;
  4955 
  4956 * Isar/Pure: scalable support for case-analysis type proofs: new
  4957 'case' language element refers to local contexts symbolically, as
  4958 produced by certain proof methods; internally, case names are attached
  4959 to theorems as "tags";
  4960 
  4961 * Isar/Pure: theory command 'hide' removes declarations from
  4962 class/type/const name spaces;
  4963 
  4964 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4965 indicate potential overloading;
  4966 
  4967 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4968 
  4969 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4970 "{a,b,c}" instead of {a,b,c};
  4971 
  4972 * Isar/Pure now provides its own version of intro/elim/dest
  4973 attributes; useful for building new logics, but beware of confusion
  4974 with the version in Provers/classical;
  4975 
  4976 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4977 case name 'antecedent';
  4978 
  4979 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4980 to the current context is now done automatically);
  4981 
  4982 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4983 for definining proof methods in ML;
  4984 
  4985 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4986 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4987 most cases, one should have to change intro!! to intro? only);
  4988 replaced "delrule" by "rule del";
  4989 
  4990 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4991 'symmetric' attribute (the latter supercedes [RS sym]);
  4992 
  4993 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4994 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4995 well (including splits);
  4996 
  4997 * Isar/Provers: Simplifier and Classical methods now support all kind
  4998 of modifiers used in the past, including 'cong', 'iff', etc.
  4999 
  5000 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5001 of Simplifier and Classical reasoner);
  5002 
  5003 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5004 now support named cases; major packages (inductive, datatype, primrec,
  5005 recdef) support case names and properly name parameters;
  5006 
  5007 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5008 monotonicity conditions are extracted to be proven at end of
  5009 calculations;
  5010 
  5011 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5012 method anyway;
  5013 
  5014 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5015 split_if split_if_asm; datatype package provides theorems foo.splits =
  5016 foo.split foo.split_asm for each datatype;
  5017 
  5018 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5019 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5020 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5021 use "(cases (simplified))" method in proper proof texts);
  5022 
  5023 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5024 
  5025 * Isar: names of theorems etc. may be natural numbers as well;
  5026 
  5027 * Isar: 'pr' command: optional arguments for goals_limit and
  5028 ProofContext.prems_limit; no longer prints theory contexts, but only
  5029 proof states;
  5030 
  5031 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5032 additional print modes to be specified; e.g. "pr(latex)" will print
  5033 proof state according to the Isabelle LaTeX style;
  5034 
  5035 * Isar: improved support for emulating tactic scripts, including proof
  5036 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5037 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5038 (for HOL datatypes);
  5039 
  5040 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5041 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5042 'proof method scripts' have to be in depth-first order;
  5043 
  5044 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5045 
  5046 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5047 should instead use individual commands for printing items
  5048 (print_commands, print_methods etc.);
  5049 
  5050 * Isar: added 'nothing' --- the empty list of theorems;
  5051 
  5052 
  5053 *** HOL ***
  5054 
  5055 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5056 corresponding virtual machine and a specification of its bytecode
  5057 verifier and a lightweight bytecode verifier, including proofs of
  5058 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5059 Cornelia Pusch (see also the homepage of project Bali at
  5060 http://isabelle.in.tum.de/Bali/);
  5061 
  5062 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5063 Clemens Ballarin;
  5064 
  5065 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5066 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5067 Rasmussen;
  5068 
  5069 * HOL/Lattice: fundamental concepts of lattice theory and order
  5070 structures, including duals, properties of bounds versus algebraic
  5071 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5072 Theorem for complete lattices etc.; may also serve as a demonstration
  5073 for abstract algebraic reasoning using axiomatic type classes, and
  5074 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5075 
  5076 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5077 von Oheimb;
  5078 
  5079 * HOL/IMPP: extension of IMP with local variables and mutually
  5080 recursive procedures, by David von Oheimb;
  5081 
  5082 * HOL/Lambda: converted into new-style theory and document;
  5083 
  5084 * HOL/ex/Multiquote: example of multiple nested quotations and
  5085 anti-quotations -- basically a generalized version of de-Bruijn
  5086 representation; very useful in avoiding lifting of operations;
  5087 
  5088 * HOL/record: added general record equality rule to simpset; fixed
  5089 select-update simplification procedure to handle extended records as
  5090 well; admit "r" as field name;
  5091 
  5092 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5093 other numeric types and also as the identity of groups, rings, etc.;
  5094 
  5095 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5096 Types nat and int belong to this axclass;
  5097 
  5098 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5099    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5100    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5101   two terms #m*u and #n*u are replaced by #(m+n)*u
  5102     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5103   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5104     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5105 
  5106 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5107 powerful prover for predicate logic but knows nothing of clasets; see
  5108 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5109 
  5110 * HOL: new version of "case_tac" subsumes both boolean case split and
  5111 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5112 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5113 
  5114 * HOL: simplification no longer dives into case-expressions: only the
  5115 selector expression is simplified, but not the remaining arms; to
  5116 enable full simplification of case-expressions for datatype t, you may
  5117 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5118 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5119 
  5120 * HOL/recdef: the recursion equations generated by 'recdef' for
  5121 function 'f' are now called f.simps instead of f.rules; if all
  5122 termination conditions are proved automatically, these simplification
  5123 rules are added to the simpset, as in primrec; rules may be named
  5124 individually as well, resulting in a separate list of theorems for
  5125 each equation;
  5126 
  5127 * HOL/While is a new theory that provides a while-combinator. It
  5128 permits the definition of tail-recursive functions without the
  5129 provision of a termination measure. The latter is necessary once the
  5130 invariant proof rule for while is applied.
  5131 
  5132 * HOL: new (overloaded) notation for the set of elements below/above
  5133 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5134 
  5135 * HOL: theorems impI, allI, ballI bound as "strip";
  5136 
  5137 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5138 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5139 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5140 
  5141 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5142 
  5143 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5144 main HOL, but was unused);
  5145 
  5146 * HOL: fewer consts declared as global (e.g. have to refer to
  5147 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5148 
  5149 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5150 in case of overlap with user translations (e.g. judgements over
  5151 tuples); (note that the underlying logical represenation is still
  5152 bogus);
  5153 
  5154 
  5155 *** ZF ***
  5156 
  5157 * ZF: simplification automatically cancels common terms in arithmetic
  5158 expressions over nat and int;
  5159 
  5160 * ZF: new treatment of nat to minimize type-checking: all operators
  5161 coerce their operands to a natural number using the function natify,
  5162 making the algebraic laws unconditional;
  5163 
  5164 * ZF: as above, for int: operators coerce their operands to an integer
  5165 using the function intify;
  5166 
  5167 * ZF: the integer library now contains many of the usual laws for the
  5168 orderings, including $<=, and monotonicity laws for $+ and $*;
  5169 
  5170 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5171 simplification;
  5172 
  5173 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5174 to the simplifier and classical reasoner simultaneously;
  5175 
  5176 
  5177 *** General ***
  5178 
  5179 * Provers: blast_tac now handles actual object-logic rules as
  5180 assumptions; note that auto_tac uses blast_tac internally as well;
  5181 
  5182 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5183 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5184 
  5185 * Provers: delrules now handles destruct rules as well (no longer need
  5186 explicit make_elim);
  5187 
  5188 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5189   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5190 use instead the strong form,
  5191   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5192 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5193 from destruct-rules;
  5194 
  5195 * Provers: Simplifier.easy_setup provides a fast path to basic
  5196 Simplifier setup for new object-logics;
  5197 
  5198 * Pure: AST translation rules no longer require constant head on LHS;
  5199 
  5200 * Pure: improved name spaces: ambiguous output is qualified; support
  5201 for hiding of names;
  5202 
  5203 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5204 XSYMBOL_HOME; no longer need to do manual configuration in most
  5205 situations;
  5206 
  5207 * system: compression of ML heaps images may now be controlled via -c
  5208 option of isabelle and isatool usedir (currently only observed by
  5209 Poly/ML);
  5210 
  5211 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5212 useful for remote X11);
  5213 
  5214 * system: provide TAGS file for Isabelle sources;
  5215 
  5216 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5217 order;
  5218 
  5219 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5220 timing flag supersedes proof_timing and Toplevel.trace;
  5221 
  5222 * ML: new combinators |>> and |>>> for incremental transformations
  5223 with secondary results (e.g. certain theory extensions):
  5224 
  5225 * ML: PureThy.add_defs gets additional argument to indicate potential
  5226 overloading (usually false);
  5227 
  5228 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5229 results;
  5230 
  5231 
  5232 
  5233 New in Isabelle99 (October 1999)
  5234 --------------------------------
  5235 
  5236 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5237 
  5238 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5239 are no longer simplified.  (This allows the simplifier to unfold recursive
  5240 functional programs.)  To restore the old behaviour, declare
  5241 
  5242     Delcongs [if_weak_cong];
  5243 
  5244 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5245 complement;
  5246 
  5247 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5248 
  5249 * HOL/datatype: mutual_induct_tac no longer exists --
  5250   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5251 
  5252 * HOL/typedef: fixed type inference for representing set; type
  5253 arguments now have to occur explicitly on the rhs as type constraints;
  5254 
  5255 * ZF: The con_defs part of an inductive definition may no longer refer
  5256 to constants declared in the same theory;
  5257 
  5258 * HOL, ZF: the function mk_cases, generated by the inductive
  5259 definition package, has lost an argument.  To simplify its result, it
  5260 uses the default simpset instead of a supplied list of theorems.
  5261 
  5262 * HOL/List: the constructors of type list are now Nil and Cons;
  5263 
  5264 * Simplifier: the type of the infix ML functions
  5265         setSSolver addSSolver setSolver addSolver
  5266 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5267 for packaging solvers. A solver is created via
  5268         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5269 where the string argument is only a comment.
  5270 
  5271 
  5272 *** Proof tools ***
  5273 
  5274 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5275 decision procedure for linear arithmetic. Currently it is used for
  5276 types `nat', `int', and `real' in HOL (see below); it can, should and
  5277 will be instantiated for other types and logics as well.
  5278 
  5279 * The simplifier now accepts rewrite rules with flexible heads, eg
  5280      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5281   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5282   matching.
  5283 
  5284 
  5285 *** General ***
  5286 
  5287 * New Isabelle/Isar subsystem provides an alternative to traditional
  5288 tactical theorem proving; together with the ProofGeneral/isar user
  5289 interface it offers an interactive environment for developing human
  5290 readable proof documents (Isar == Intelligible semi-automated
  5291 reasoning); for further information see isatool doc isar-ref,
  5292 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5293 
  5294 * improved and simplified presentation of theories: better HTML markup
  5295 (including colors), graph views in several sizes; isatool usedir now
  5296 provides a proper interface for user theories (via -P option); actual
  5297 document preparation based on (PDF)LaTeX is available as well (for
  5298 new-style theories only); see isatool doc system for more information;
  5299 
  5300 * native support for Proof General, both for classic Isabelle and
  5301 Isabelle/Isar;
  5302 
  5303 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5304 using the graph browser tool;
  5305 
  5306 * Isabelle manuals now also available as PDF;
  5307 
  5308 * theory loader rewritten from scratch (may not be fully
  5309 bug-compatible); old loadpath variable has been replaced by show_path,
  5310 add_path, del_path, reset_path functions; new operations such as
  5311 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5312 isatool doc ref);
  5313 
  5314 * improved isatool install: option -k creates KDE application icon,
  5315 option -p DIR installs standalone binaries;
  5316 
  5317 * added ML_PLATFORM setting (useful for cross-platform installations);
  5318 more robust handling of platform specific ML images for SML/NJ;
  5319 
  5320 * the settings environment is now statically scoped, i.e. it is never
  5321 created again in sub-processes invoked from isabelle, isatool, or
  5322 Isabelle;
  5323 
  5324 * path element specification '~~' refers to '$ISABELLE_HOME';
  5325 
  5326 * in locales, the "assumes" and "defines" parts may be omitted if
  5327 empty;
  5328 
  5329 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5330 long arrows);
  5331 
  5332 * new print_mode "HTML";
  5333 
  5334 * new flag show_tags controls display of tags of theorems (which are
  5335 basically just comments that may be attached by some tools);
  5336 
  5337 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5338 mode and goal output format:
  5339 
  5340 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5341 244c244
  5342 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5343 ---
  5344 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5345 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5346 181c181
  5347 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5348 ---
  5349 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5350 
  5351 * function bind_thms stores lists of theorems (cf. bind_thm);
  5352 
  5353 * new shorthand tactics ftac, eatac, datac, fatac;
  5354 
  5355 * qed (and friends) now accept "" as result name; in that case the
  5356 theorem is not stored, but proper checks and presentation of the
  5357 result still apply;
  5358 
  5359 * theorem database now also indexes constants "Trueprop", "all",
  5360 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5361 
  5362 
  5363 *** HOL ***
  5364 
  5365 ** HOL arithmetic **
  5366 
  5367 * There are now decision procedures for linear arithmetic over nat and
  5368 int:
  5369 
  5370 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5371 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5372 are treated as atomic; subformulae not involving type `nat' or `int'
  5373 are ignored; quantified subformulae are ignored unless they are
  5374 positive universal or negative existential. The tactic has to be
  5375 invoked by hand and can be a little bit slow. In particular, the
  5376 running time is exponential in the number of occurrences of `min' and
  5377 `max', and `-' on `nat'.
  5378 
  5379 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5380 (negated) (in)equalities among the premises and the conclusion into
  5381 account (i.e. no compound formulae) and does not know about `min' and
  5382 `max', and `-' on `nat'. It is fast and is used automatically by the
  5383 simplifier.
  5384 
  5385 NB: At the moment, these decision procedures do not cope with mixed
  5386 nat/int formulae where the two parts interact, such as `m < n ==>
  5387 int(m) < int(n)'.
  5388 
  5389 * HOL/Numeral provides a generic theory of numerals (encoded
  5390 efficiently as bit strings); setup for types nat/int/real is in place;
  5391 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5392 int, existing theories and proof scripts may require a few additional
  5393 type constraints;
  5394 
  5395 * integer division and remainder can now be performed on constant
  5396 arguments;
  5397 
  5398 * many properties of integer multiplication, division and remainder
  5399 are now available;
  5400 
  5401 * An interface to the Stanford Validity Checker (SVC) is available through the
  5402 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5403 are proved automatically.  SVC must be installed separately, and its results
  5404 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5405 invocation of the underlying oracle).  For SVC see
  5406   http://verify.stanford.edu/SVC
  5407 
  5408 * IsaMakefile: the HOL-Real target now builds an actual image;
  5409 
  5410 
  5411 ** HOL misc **
  5412 
  5413 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5414 (in Isabelle/Isar) -- by Gertrud Bauer;
  5415 
  5416 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5417 analysis for assembly languages with subtypes;
  5418 
  5419 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5420 -- avoids syntactic ambiguities and treats state, transition, and
  5421 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5422 changed syntax and (many) tactics;
  5423 
  5424 * HOL/inductive: Now also handles more general introduction rules such
  5425   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5426   theorems are now maintained within the theory (maintained via the
  5427   "mono" attribute);
  5428 
  5429 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5430   (using function types) such as
  5431 
  5432   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5433 
  5434 * HOL/record: record_simproc (part of the default simpset) takes care
  5435 of selectors applied to updated records; record_split_tac is no longer
  5436 part of the default claset; update_defs may now be removed from the
  5437 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5438 
  5439   claset_ref () := claset() addSWrapper record_split_wrapper;
  5440   Delsimprocs [record_simproc]
  5441 
  5442 * HOL/typedef: fixed type inference for representing set; type
  5443 arguments now have to occur explicitly on the rhs as type constraints;
  5444 
  5445 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5446 names rather than an ML expression;
  5447 
  5448 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5449 supplied later.  Program schemes can be defined, such as
  5450     "While B C s = (if B s then While B C (C s) else s)"
  5451 where the well-founded relation can be chosen after B and C have been given.
  5452 
  5453 * HOL/List: the constructors of type list are now Nil and Cons;
  5454 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5455 course, ML tools referring to List.list.op # etc. have to be adapted;
  5456 
  5457 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5458 disabled by default; run isabelle with option -m HOL to get back to
  5459 the original Gordon/HOL-style output;
  5460 
  5461 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5462 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5463 
  5464 * HOL basic syntax simplified (more orthogonal): all variants of
  5465 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5466 Eps operator is provided as well: "SOME x. P[x]";
  5467 
  5468 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5469 
  5470 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5471 thus available for user theories;
  5472 
  5473 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5474 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5475 time;
  5476 
  5477 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5478 several times and then mp;
  5479 
  5480 
  5481 *** LK ***
  5482 
  5483 * the notation <<...>> is now available as a notation for sequences of
  5484 formulas;
  5485 
  5486 * the simplifier is now installed
  5487 
  5488 * the axiom system has been generalized (thanks to Soren Heilmann)
  5489 
  5490 * the classical reasoner now has a default rule database
  5491 
  5492 
  5493 *** ZF ***
  5494 
  5495 * new primrec section allows primitive recursive functions to be given
  5496 directly (as in HOL) over datatypes and the natural numbers;
  5497 
  5498 * new tactics induct_tac and exhaust_tac for induction (or case
  5499 analysis) over datatypes and the natural numbers;
  5500 
  5501 * the datatype declaration of type T now defines the recursor T_rec;
  5502 
  5503 * simplification automatically does freeness reasoning for datatype
  5504 constructors;
  5505 
  5506 * automatic type-inference, with AddTCs command to insert new
  5507 type-checking rules;
  5508 
  5509 * datatype introduction rules are now added as Safe Introduction rules
  5510 to the claset;
  5511 
  5512 * the syntax "if P then x else y" is now available in addition to
  5513 if(P,x,y);
  5514 
  5515 
  5516 *** Internal programming interfaces ***
  5517 
  5518 * tuned simplifier trace output; new flag debug_simp;
  5519 
  5520 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5521 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5522 
  5523 * AxClass.axclass_tac lost the theory argument;
  5524 
  5525 * tuned current_goals_markers semantics: begin / end goal avoids
  5526 printing empty lines;
  5527 
  5528 * removed prs and prs_fn hook, which was broken because it did not
  5529 include \n in its semantics, forcing writeln to add one
  5530 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5531 string -> unit if you really want to output text without newline;
  5532 
  5533 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5534 plain output, interface builders may have to enable 'isabelle_font'
  5535 mode to get Isabelle font glyphs as before;
  5536 
  5537 * refined token_translation interface; INCOMPATIBILITY: output length
  5538 now of type real instead of int;
  5539 
  5540 * theory loader actions may be traced via new ThyInfo.add_hook
  5541 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5542 your own database of information attached to *whole* theories -- as
  5543 opposed to intra-theory data slots offered via TheoryDataFun;
  5544 
  5545 * proper handling of dangling sort hypotheses (at last!);
  5546 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5547 extra sort hypotheses that can be witnessed from the type signature;
  5548 the force_strip_shyps flag is gone, any remaining shyps are simply
  5549 left in the theorem (with a warning issued by strip_shyps_warning);
  5550 
  5551 
  5552 
  5553 New in Isabelle98-1 (October 1998)
  5554 ----------------------------------
  5555 
  5556 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5557 
  5558 * several changes of automated proof tools;
  5559 
  5560 * HOL: major changes to the inductive and datatype packages, including
  5561 some minor incompatibilities of theory syntax;
  5562 
  5563 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5564 called `inj_on';
  5565 
  5566 * HOL: removed duplicate thms in Arith:
  5567   less_imp_add_less  should be replaced by  trans_less_add1
  5568   le_imp_add_le      should be replaced by  trans_le_add1
  5569 
  5570 * HOL: unary minus is now overloaded (new type constraints may be
  5571 required);
  5572 
  5573 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5574 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5575 now taken as an integer constant.
  5576 
  5577 * Pure: ML function 'theory_of' renamed to 'theory';
  5578 
  5579 
  5580 *** Proof tools ***
  5581 
  5582 * Simplifier:
  5583   1. Asm_full_simp_tac is now more aggressive.
  5584      1. It will sometimes reorient premises if that increases their power to
  5585         simplify.
  5586      2. It does no longer proceed strictly from left to right but may also
  5587         rotate premises to achieve further simplification.
  5588      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5589      old Asm_full_simp_tac in that it does not rotate premises.
  5590   2. The simplifier now knows a little bit about nat-arithmetic.
  5591 
  5592 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5593 allows for selected deletion of wrappers, by introduction of names for
  5594 wrapper functionals.  This implies that addbefore, addSbefore,
  5595 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5596 and that adding two tactics with the same name overwrites the first
  5597 one (emitting a warning).
  5598   type wrapper = (int -> tactic) -> (int -> tactic)
  5599   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5600   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5601   delWrapper, delSWrapper: claset *  string            -> claset
  5602   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5603 
  5604 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5605 semantics; addbefore now affects only the unsafe part of step_tac
  5606 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5607 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5608 by Force_tac;
  5609 
  5610 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5611 compWrapper; added safe wrapper (and access functions for it);
  5612 
  5613 * HOL/split_all_tac is now much faster and fails if there is nothing
  5614 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5615 and the names of the automatically generated variables have changed.
  5616 split_all_tac has moved within claset() from unsafe wrappers to safe
  5617 wrappers, which means that !!-bound variables are split much more
  5618 aggressively, and safe_tac and clarify_tac now split such variables.
  5619 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5620 Note: the same holds for record_split_tac, which does the job of
  5621 split_all_tac for record fields.
  5622 
  5623 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5624 permanently to the default simpset using Addsplits just like
  5625 Addsimps. They can be removed via Delsplits just like
  5626 Delsimps. Lower-case versions are also available.
  5627 
  5628 * HOL/Simplifier: The rule split_if is now part of the default
  5629 simpset. This means that the simplifier will eliminate all occurrences
  5630 of if-then-else in the conclusion of a goal. To prevent this, you can
  5631 either remove split_if completely from the default simpset by
  5632 `Delsplits [split_if]' or remove it in a specific call of the
  5633 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5634 other case splitting rules to/from the default simpset: every datatype
  5635 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5636 t is the name of the datatype).
  5637 
  5638 * Classical reasoner / Simplifier combination: new force_tac (and
  5639 derivatives Force_tac, force) combines rewriting and classical
  5640 reasoning (and whatever other tools) similarly to auto_tac, but is
  5641 aimed to solve the given subgoal completely.
  5642 
  5643 
  5644 *** General ***
  5645 
  5646 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5647 and `goalw': the theory is no longer needed as an explicit argument -
  5648 the current theory context is used; assumptions are no longer returned
  5649 at the ML-level unless one of them starts with ==> or !!; it is
  5650 recommended to convert to these new commands using isatool fixgoal
  5651 (backup your sources first!);
  5652 
  5653 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5654 the current theory context, and 'theory' to lookup stored theories;
  5655 
  5656 * new theory section 'locale' for declaring constants, assumptions and
  5657 definitions that have local scope;
  5658 
  5659 * new theory section 'nonterminals' for purely syntactic types;
  5660 
  5661 * new theory section 'setup' for generic ML setup functions
  5662 (e.g. package initialization);
  5663 
  5664 * the distribution now includes Isabelle icons: see
  5665 lib/logo/isabelle-{small,tiny}.xpm;
  5666 
  5667 * isatool install - install binaries with absolute references to
  5668 ISABELLE_HOME/bin;
  5669 
  5670 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5671 
  5672 * print mode 'emacs' reserved for Isamode;
  5673 
  5674 * support multiple print (ast) translations per constant name;
  5675 
  5676 * theorems involving oracles are now printed with a suffixed [!];
  5677 
  5678 
  5679 *** HOL ***
  5680 
  5681 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5682 
  5683 * HOL/inductive package reorganized and improved: now supports mutual
  5684 definitions such as
  5685 
  5686   inductive EVEN ODD
  5687     intrs
  5688       null "0 : EVEN"
  5689       oddI "n : EVEN ==> Suc n : ODD"
  5690       evenI "n : ODD ==> Suc n : EVEN"
  5691 
  5692 new theorem list "elims" contains an elimination rule for each of the
  5693 recursive sets; inductive definitions now handle disjunctive premises
  5694 correctly (also ZF);
  5695 
  5696 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5697 "mutual_induct" no longer exists - the induction rule is always
  5698 contained in "induct";
  5699 
  5700 
  5701 * HOL/datatype package re-implemented and greatly improved: now
  5702 supports mutually recursive datatypes such as
  5703 
  5704   datatype
  5705     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5706             | SUM ('a aexp) ('a aexp)
  5707             | DIFF ('a aexp) ('a aexp)
  5708             | NUM 'a
  5709   and
  5710     'a bexp = LESS ('a aexp) ('a aexp)
  5711             | AND ('a bexp) ('a bexp)
  5712             | OR ('a bexp) ('a bexp)
  5713 
  5714 as well as indirectly recursive datatypes such as
  5715 
  5716   datatype
  5717     ('a, 'b) term = Var 'a
  5718                   | App 'b ((('a, 'b) term) list)
  5719 
  5720 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5721 induction on mutually / indirectly recursive datatypes.
  5722 
  5723 Primrec equations are now stored in theory and can be accessed via
  5724 <function_name>.simps.
  5725 
  5726 INCOMPATIBILITIES:
  5727 
  5728   - Theories using datatypes must now have theory Datatype as an
  5729     ancestor.
  5730   - The specific <typename>.induct_tac no longer exists - use the
  5731     generic induct_tac instead.
  5732   - natE has been renamed to nat.exhaust - use exhaust_tac
  5733     instead of res_inst_tac ... natE. Note that the variable
  5734     names in nat.exhaust differ from the names in natE, this
  5735     may cause some "fragile" proofs to fail.
  5736   - The theorems split_<typename>_case and split_<typename>_case_asm
  5737     have been renamed to <typename>.split and <typename>.split_asm.
  5738   - Since default sorts of type variables are now handled correctly,
  5739     some datatype definitions may have to be annotated with explicit
  5740     sort constraints.
  5741   - Primrec definitions no longer require function name and type
  5742     of recursive argument.
  5743 
  5744 Consider using isatool fixdatatype to adapt your theories and proof
  5745 scripts to the new package (backup your sources first!).
  5746 
  5747 
  5748 * HOL/record package: considerably improved implementation; now
  5749 includes concrete syntax for record types, terms, updates; theorems
  5750 for surjective pairing and splitting !!-bound record variables; proof
  5751 support is as follows:
  5752 
  5753   1) standard conversions (selectors or updates applied to record
  5754 constructor terms) are part of the standard simpset;
  5755 
  5756   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5757 made part of standard simpset and claset via addIffs;
  5758 
  5759   3) a tactic for record field splitting (record_split_tac) is part of
  5760 the standard claset (addSWrapper);
  5761 
  5762 To get a better idea about these rules you may retrieve them via
  5763 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5764 the name of your record type.
  5765 
  5766 The split tactic 3) conceptually simplifies by the following rule:
  5767 
  5768   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5769 
  5770 Thus any record variable that is bound by meta-all will automatically
  5771 blow up into some record constructor term, consequently the
  5772 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5773 solve record problems automatically.
  5774 
  5775 
  5776 * reorganized the main HOL image: HOL/Integ and String loaded by
  5777 default; theory Main includes everything;
  5778 
  5779 * automatic simplification of integer sums and comparisons, using cancellation;
  5780 
  5781 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5782 
  5783 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5784 
  5785 * many new identities for unions, intersections, set difference, etc.;
  5786 
  5787 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5788 called split_if, split_split, split_sum_case and split_nat_case (to go
  5789 with add/delsplits);
  5790 
  5791 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5792 (?x::unit) = (); this is made part of the default simpset, which COULD
  5793 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5794 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5795 unit_abs_eta_conv is added in order to counter the effect of
  5796 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5797 %u.f();
  5798 
  5799 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5800 makes more sense);
  5801 
  5802 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5803   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5804   disjointness reasoning but breaking a few old proofs.
  5805 
  5806 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5807 to 'converse' from 'inverse' (for compatibility with ZF and some
  5808 literature);
  5809 
  5810 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5811 the well-founded relation;
  5812 
  5813 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5814     Compl A.  The "Compl" syntax remains available as input syntax for this
  5815     release ONLY.
  5816 
  5817 * HOL/Update: new theory of function updates:
  5818     f(a:=b) == %x. if x=a then b else f x
  5819 may also be iterated as in f(a:=b,c:=d,...);
  5820 
  5821 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5822 
  5823 * HOL/List:
  5824   - new function list_update written xs[i:=v] that updates the i-th
  5825     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5826   - new function `upt' written [i..j(] which generates the list
  5827     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5828     bound write [i..j], which is a shorthand for [i..j+1(].
  5829   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5830 
  5831 * HOL/Arith:
  5832   - removed 'pred' (predecessor) function;
  5833   - generalized some theorems about n-1;
  5834   - many new laws about "div" and "mod";
  5835   - new laws about greatest common divisors (see theory ex/Primes);
  5836 
  5837 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5838 instead of "inverse";
  5839 
  5840 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5841   of the multiset ordering;
  5842 
  5843 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5844   (not included by default);
  5845 
  5846 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5847 
  5848 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5849   programs, i.e. different program variables may have different types.
  5850 
  5851 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5852   [previously, this check worked only if the rewrite rule was unconditional]
  5853   Now rew can involve either definitions or equalities (either == or =).
  5854 
  5855 
  5856 *** ZF ***
  5857 
  5858 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5859   only the theorems proved on ZF.ML;
  5860 
  5861 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5862   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5863   disjointness reasoning but breaking a few old proofs.
  5864 
  5865 * ZF/Update: new theory of function updates
  5866     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5867   may also be iterated as in f(a:=b,c:=d,...);
  5868 
  5869 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5870 
  5871 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5872   [previously, this check worked only if the rewrite rule was unconditional]
  5873   Now rew can involve either definitions or equalities (either == or =).
  5874 
  5875 * case_tac provided for compatibility with HOL
  5876     (like the old excluded_middle_tac, but with subgoals swapped)
  5877 
  5878 
  5879 *** Internal programming interfaces ***
  5880 
  5881 * Pure: several new basic modules made available for general use, see
  5882 also src/Pure/README;
  5883 
  5884 * improved the theory data mechanism to support encapsulation (data
  5885 kind name replaced by private Object.kind, acting as authorization
  5886 key); new type-safe user interface via functor TheoryDataFun; generic
  5887 print_data function becomes basically useless;
  5888 
  5889 * removed global_names compatibility flag -- all theory declarations
  5890 are qualified by default;
  5891 
  5892 * module Pure/Syntax now offers quote / antiquote translation
  5893 functions (useful for Hoare logic etc. with implicit dependencies);
  5894 see HOL/ex/Antiquote for an example use;
  5895 
  5896 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5897 cterm -> thm;
  5898 
  5899 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5900 subgoal;
  5901 
  5902 * Display.print_goals function moved to Locale.print_goals;
  5903 
  5904 * standard print function for goals supports current_goals_markers
  5905 variable for marking begin of proof, end of proof, start of goal; the
  5906 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5907 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5908 for example;
  5909 
  5910 
  5911 
  5912 New in Isabelle98 (January 1998)
  5913 --------------------------------
  5914 
  5915 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5916 
  5917 * changed lexical syntax of terms / types: dots made part of long
  5918 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5919 
  5920 * simpset (and claset) reference variable replaced by functions
  5921 simpset / simpset_ref;
  5922 
  5923 * no longer supports theory aliases (via merge) and non-trivial
  5924 implicit merge of thms' signatures;
  5925 
  5926 * most internal names of constants changed due to qualified names;
  5927 
  5928 * changed Pure/Sequence interface (see Pure/seq.ML);
  5929 
  5930 
  5931 *** General Changes ***
  5932 
  5933 * hierachically structured name spaces (for consts, types, axms, thms
  5934 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5935 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5936 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5937 long_names for fully qualified output names; NOTE: ML programs
  5938 (special tactics, packages etc.) referring to internal names may have
  5939 to be adapted to cope with fully qualified names; in case of severe
  5940 backward campatibility problems try setting 'global_names' at compile
  5941 time to have enrything declared within a flat name space; one may also
  5942 fine tune name declarations in theories via the 'global' and 'local'
  5943 section;
  5944 
  5945 * reimplemented the implicit simpset and claset using the new anytype
  5946 data filed in signatures; references simpset:simpset ref etc. are
  5947 replaced by functions simpset:unit->simpset and
  5948 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5949 to patch your ML files accordingly;
  5950 
  5951 * HTML output now includes theory graph data for display with Java
  5952 applet or isatool browser; data generated automatically via isatool
  5953 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5954 
  5955 * defs may now be conditional; improved rewrite_goals_tac to handle
  5956 conditional equations;
  5957 
  5958 * defs now admits additional type arguments, using TYPE('a) syntax;
  5959 
  5960 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5961 creates a new theory node; implicit merge of thms' signatures is
  5962 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5963 transfer:theory->thm->thm in (rare) cases;
  5964 
  5965 * improved handling of draft signatures / theories; draft thms (and
  5966 ctyps, cterms) are automatically promoted to real ones;
  5967 
  5968 * slightly changed interfaces for oracles: admit many per theory, named
  5969 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5970 
  5971 * print_goals: optional output of const types (set show_consts and
  5972 show_types);
  5973 
  5974 * improved output of warnings (###) and errors (***);
  5975 
  5976 * subgoal_tac displays a warning if the new subgoal has type variables;
  5977 
  5978 * removed old README and Makefiles;
  5979 
  5980 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5981 
  5982 * removed obsolete init_pps and init_database;
  5983 
  5984 * deleted the obsolete tactical STATE, which was declared by
  5985     fun STATE tacfun st = tacfun st st;
  5986 
  5987 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5988 (which abbreviates $HOME);
  5989 
  5990 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5991 use isatool fixseq to adapt your ML programs (this works for fully
  5992 qualified references to the Sequence structure only!);
  5993 
  5994 * use_thy no longer requires writable current directory; it always
  5995 reloads .ML *and* .thy file, if either one is out of date;
  5996 
  5997 
  5998 *** Classical Reasoner ***
  5999 
  6000 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6001 tactics that use classical reasoning to simplify a subgoal without
  6002 splitting it into several subgoals;
  6003 
  6004 * Safe_tac: like safe_tac but uses the default claset;
  6005 
  6006 
  6007 *** Simplifier ***
  6008 
  6009 * added simplification meta rules:
  6010     (asm_)(full_)simplify: simpset -> thm -> thm;
  6011 
  6012 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6013 logics (again);
  6014 
  6015 * added prems argument to simplification procedures;
  6016 
  6017 * HOL, FOL, ZF: added infix function `addsplits':
  6018   instead of `<simpset> setloop (split_tac <thms>)'
  6019   you can simply write `<simpset> addsplits <thms>'
  6020 
  6021 
  6022 *** Syntax ***
  6023 
  6024 * TYPE('a) syntax for type reflection terms;
  6025 
  6026 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6027 
  6028 * pretty printer: changed order of mixfix annotation preference (again!);
  6029 
  6030 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6031 
  6032 
  6033 *** HOL ***
  6034 
  6035 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6036   with `addloop' of the simplifier to faciliate case splitting in premises.
  6037 
  6038 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6039 
  6040 * HOL/Auth: new protocol proofs including some for the Internet
  6041   protocol TLS;
  6042 
  6043 * HOL/Map: new theory of `maps' a la VDM;
  6044 
  6045 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6046 cancelling out common nat summands from =, <, <= (in)equalities, or
  6047 differences; simplification procedures nat_cancel_factor for
  6048 cancelling common factor from =, <, <= (in)equalities over natural
  6049 sums; nat_cancel contains both kinds of procedures, it is installed by
  6050 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6051 
  6052 * HOL/simplifier: terms of the form
  6053   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6054   are rewritten to
  6055   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6056   and those of the form
  6057   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6058   are rewritten to
  6059   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6060 
  6061 * HOL/datatype
  6062   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6063 
  6064   P(t_case f1 ... fn x) =
  6065      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6066         ...
  6067        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6068      )
  6069 
  6070   and a theorem `split_t_case_asm' of the form
  6071 
  6072   P(t_case f1 ... fn x) =
  6073     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6074         ...
  6075        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6076      )
  6077   which can be added to a simpset via `addsplits'. The existing theorems
  6078   expand_list_case and expand_option_case have been renamed to
  6079   split_list_case and split_option_case.
  6080 
  6081 * HOL/Arithmetic:
  6082   - `pred n' is automatically converted to `n-1'.
  6083     Users are strongly encouraged not to use `pred' any longer,
  6084     because it will disappear altogether at some point.
  6085   - Users are strongly encouraged to write "0 < n" rather than
  6086     "n ~= 0". Theorems and proof tools have been modified towards this
  6087     `standard'.
  6088 
  6089 * HOL/Lists:
  6090   the function "set_of_list" has been renamed "set" (and its theorems too);
  6091   the function "nth" now takes its arguments in the reverse order and
  6092   has acquired the infix notation "!" as in "xs!n".
  6093 
  6094 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6095 
  6096 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6097   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6098 
  6099 * HOL/record: extensible records with schematic structural subtyping
  6100 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6101 still lacks various theorems and concrete record syntax;
  6102 
  6103 
  6104 *** HOLCF ***
  6105 
  6106 * removed "axioms" and "generated by" sections;
  6107 
  6108 * replaced "ops" section by extended "consts" section, which is capable of
  6109   handling the continuous function space "->" directly;
  6110 
  6111 * domain package:
  6112   . proves theorems immediately and stores them in the theory,
  6113   . creates hierachical name space,
  6114   . now uses normal mixfix annotations (instead of cinfix...),
  6115   . minor changes to some names and values (for consistency),
  6116   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6117   . separator between mutual domain defs: changed "," to "and",
  6118   . improved handling of sort constraints;  now they have to
  6119     appear on the left-hand side of the equations only;
  6120 
  6121 * fixed LAM <x,y,zs>.b syntax;
  6122 
  6123 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6124 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6125 
  6126 
  6127 *** FOL and ZF ***
  6128 
  6129 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6130   with `addloop' of the simplifier to faciliate case splitting in premises.
  6131 
  6132 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6133 in HOL, they strip ALL and --> from proved theorems;
  6134 
  6135 
  6136 
  6137 New in Isabelle94-8 (May 1997)
  6138 ------------------------------
  6139 
  6140 *** General Changes ***
  6141 
  6142 * new utilities to build / run / maintain Isabelle etc. (in parts
  6143 still somewhat experimental); old Makefiles etc. still functional;
  6144 
  6145 * new 'Isabelle System Manual';
  6146 
  6147 * INSTALL text, together with ./configure and ./build scripts;
  6148 
  6149 * reimplemented type inference for greater efficiency, better error
  6150 messages and clean internal interface;
  6151 
  6152 * prlim command for dealing with lots of subgoals (an easier way of
  6153 setting goals_limit);
  6154 
  6155 
  6156 *** Syntax ***
  6157 
  6158 * supports alternative (named) syntax tables (parser and pretty
  6159 printer); internal interface is provided by add_modesyntax(_i);
  6160 
  6161 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6162 be used in conjunction with the Isabelle symbol font; uses the
  6163 "symbols" syntax table;
  6164 
  6165 * added token_translation interface (may translate name tokens in
  6166 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6167 the current print_mode); IMPORTANT: user print translation functions
  6168 are responsible for marking newly introduced bounds
  6169 (Syntax.mark_boundT);
  6170 
  6171 * token translations for modes "xterm" and "xterm_color" that display
  6172 names in bold, underline etc. or colors (which requires a color
  6173 version of xterm);
  6174 
  6175 * infixes may now be declared with names independent of their syntax;
  6176 
  6177 * added typed_print_translation (like print_translation, but may
  6178 access type of constant);
  6179 
  6180 
  6181 *** Classical Reasoner ***
  6182 
  6183 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6184 some limitations.  Blast_tac...
  6185   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6186   + ignores elimination rules that don't have the correct format
  6187         (the conclusion MUST be a formula variable)
  6188   + ignores types, which can make HOL proofs fail
  6189   + rules must not require higher-order unification, e.g. apply_type in ZF
  6190     [message "Function Var's argument not a bound variable" relates to this]
  6191   + its proof strategy is more general but can actually be slower
  6192 
  6193 * substitution with equality assumptions no longer permutes other
  6194 assumptions;
  6195 
  6196 * minor changes in semantics of addafter (now called addaltern); renamed
  6197 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6198 (and access functions for it);
  6199 
  6200 * improved combination of classical reasoner and simplifier:
  6201   + functions for handling clasimpsets
  6202   + improvement of addss: now the simplifier is called _after_ the
  6203     safe steps.
  6204   + safe variant of addss called addSss: uses safe simplifications
  6205     _during_ the safe steps. It is more complete as it allows multiple
  6206     instantiations of unknowns (e.g. with slow_tac).
  6207 
  6208 *** Simplifier ***
  6209 
  6210 * added interface for simplification procedures (functions that
  6211 produce *proven* rewrite rules on the fly, depending on current
  6212 redex);
  6213 
  6214 * ordering on terms as parameter (used for ordered rewriting);
  6215 
  6216 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6217 
  6218 * the solver is now split into a safe and an unsafe part.
  6219 This should be invisible for the normal user, except that the
  6220 functions setsolver and addsolver have been renamed to setSolver and
  6221 addSolver; added safe_asm_full_simp_tac;
  6222 
  6223 
  6224 *** HOL ***
  6225 
  6226 * a generic induction tactic `induct_tac' which works for all datatypes and
  6227 also for type `nat';
  6228 
  6229 * a generic case distinction tactic `exhaust_tac' which works for all
  6230 datatypes and also for type `nat';
  6231 
  6232 * each datatype comes with a function `size';
  6233 
  6234 * patterns in case expressions allow tuple patterns as arguments to
  6235 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6236 
  6237 * primrec now also works with type nat;
  6238 
  6239 * recdef: a new declaration form, allows general recursive functions to be
  6240 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6241 
  6242 * the constant for negation has been renamed from "not" to "Not" to
  6243 harmonize with FOL, ZF, LK, etc.;
  6244 
  6245 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6246 infinite lists;
  6247 
  6248 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6249 
  6250 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6251 problems in commutative rings, using axiomatic type classes for + and *;
  6252 
  6253 * more examples in HOL/MiniML and HOL/Auth;
  6254 
  6255 * more default rewrite rules for quantifiers, union/intersection;
  6256 
  6257 * a new constant `arbitrary == @x.False';
  6258 
  6259