NEWS
author wenzelm
Sat Jul 25 10:31:27 2009 +0200 (2009-07-25)
changeset 32187 cca43ca13f4f
parent 32151 2f65c45c2e7e
child 32216 2f3d65d15149
permissions -rw-r--r--
renamed structure Display_Goal to Goal_Display;
     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 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   122 functors have their own ML name space there is no point to mark them
   123 separately.)  Minor INCOMPATIBILITY.
   124 
   125 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   126 
   127 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   128 cominators for "args".  INCOMPATIBILITY, need to use simplified
   129 Attrib/Method.setup introduced in Isabelle2009.
   130 
   131 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   132 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   133 last resort.  INCOMPATIBILITY.
   134 
   135 * Display.pretty_thm now requires a proper context (cf. former
   136 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   137 or even Display.pretty_thm_without_context as last resort.
   138 INCOMPATIBILITY.
   139 
   140 
   141 *** System ***
   142 
   143 * Discontinued support for Poly/ML 4.x versions.
   144 
   145 * Removed "compress" option from isabelle-process and isabelle usedir;
   146 this is always enabled.
   147 
   148 * More fine-grained control of proof parallelism, cf.
   149 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   150 
   151 
   152 
   153 New in Isabelle2009 (April 2009)
   154 --------------------------------
   155 
   156 *** General ***
   157 
   158 * Simplified main Isabelle executables, with less surprises on
   159 case-insensitive file-systems (such as Mac OS).
   160 
   161   - The main Isabelle tool wrapper is now called "isabelle" instead of
   162     "isatool."
   163 
   164   - The former "isabelle" alias for "isabelle-process" has been
   165     removed (should rarely occur to regular users).
   166 
   167   - The former "isabelle-interface" and its alias "Isabelle" have been
   168     removed (interfaces are now regular Isabelle tools).
   169 
   170 Within scripts and make files, the Isabelle environment variables
   171 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   172 respectively.  (The latter are still available as legacy feature.)
   173 
   174 The old isabelle-interface wrapper could react in confusing ways if
   175 the interface was uninstalled or changed otherwise.  Individual
   176 interface tool configuration is now more explicit, see also the
   177 Isabelle system manual.  In particular, Proof General is now available
   178 via "isabelle emacs".
   179 
   180 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   181 purge installed copies of Isabelle executables and re-run "isabelle
   182 install -p ...", or use symlinks.
   183 
   184 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   185 old ~/isabelle, which was slightly non-standard and apt to cause
   186 surprises on case-insensitive file-systems (such as Mac OS).
   187 
   188 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   189 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   190 care is required when using older releases of Isabelle.  Note that
   191 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   192 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   193 
   194 * Proofs of fully specified statements are run in parallel on
   195 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   196 a regular 4-core machine, if the initial heap space is made reasonably
   197 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   198 
   199 * The main reference manuals ("isar-ref", "implementation", and
   200 "system") have been updated and extended.  Formally checked references
   201 as hyperlinks are now available uniformly.
   202 
   203 
   204 *** Pure ***
   205 
   206 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   207 respects.  The most important changes are listed below.  See the
   208 Tutorial on Locales ("locales" manual) for details.
   209 
   210 - In locale expressions, instantiation replaces renaming.  Parameters
   211 must be declared in a for clause.  To aid compatibility with previous
   212 parameter inheritance, in locale declarations, parameters that are not
   213 'touched' (instantiation position "_" or omitted) are implicitly added
   214 with their syntax at the beginning of the for clause.
   215 
   216 - Syntax from abbreviations and definitions in locales is available in
   217 locale expressions and context elements.  The latter is particularly
   218 useful in locale declarations.
   219 
   220 - More flexible mechanisms to qualify names generated by locale
   221 expressions.  Qualifiers (prefixes) may be specified in locale
   222 expressions, and can be marked as mandatory (syntax: "name!:") or
   223 optional (syntax "name?:").  The default depends for plain "name:"
   224 depends on the situation where a locale expression is used: in
   225 commands 'locale' and 'sublocale' prefixes are optional, in
   226 'interpretation' and 'interpret' prefixes are mandatory.  The old
   227 implicit qualifiers derived from the parameter names of a locale are
   228 no longer generated.
   229 
   230 - Command "sublocale l < e" replaces "interpretation l < e".  The
   231 instantiation clause in "interpretation" and "interpret" (square
   232 brackets) is no longer available.  Use locale expressions.
   233 
   234 - When converting proof scripts, mandatory qualifiers in
   235 'interpretation' and 'interpret' should be retained by default, even
   236 if this is an INCOMPATIBILITY compared to former behavior.  In the
   237 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   238 in locale expressions range over a single locale instance only.
   239 
   240 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   241 In existing theorem specifications replace the includes element by the
   242 respective context elements of the included locale, omitting those
   243 that are already present in the theorem specification.  Multiple
   244 assume elements of a locale should be replaced by a single one
   245 involving the locale predicate.  In the proof body, declarations (most
   246 notably theorems) may be regained by interpreting the respective
   247 locales in the proof context as required (command "interpret").
   248 
   249 If using "includes" in replacement of a target solely because the
   250 parameter types in the theorem are not as general as in the target,
   251 consider declaring a new locale with additional type constraints on
   252 the parameters (context element "constrains").
   253 
   254 - Discontinued "locale (open)".  INCOMPATIBILITY.
   255 
   256 - Locale interpretation commands no longer attempt to simplify goal.
   257 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   258 methods intro_locales and unfold_locales to clarify.
   259 
   260 - Locale interpretation commands no longer accept interpretation
   261 attributes.  INCOMPATIBILITY.
   262 
   263 * Class declaration: so-called "base sort" must not be given in import
   264 list any longer, but is inferred from the specification.  Particularly
   265 in HOL, write
   266 
   267     class foo = ...
   268 
   269 instead of
   270 
   271     class foo = type + ...
   272 
   273 * Class target: global versions of theorems stemming do not carry a
   274 parameter prefix any longer.  INCOMPATIBILITY.
   275 
   276 * Class 'instance' command no longer accepts attached definitions.
   277 INCOMPATIBILITY, use proper 'instantiation' target instead.
   278 
   279 * Recovered hiding of consts, which was accidentally broken in
   280 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   281 makes c inaccessible; consider using ``hide (open) const c'' instead.
   282 
   283 * Slightly more coherent Pure syntax, with updated documentation in
   284 isar-ref manual.  Removed locales meta_term_syntax and
   285 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   286 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   287 directly in regular applications.
   288 
   289 * There is a new syntactic category "float_const" for signed decimal
   290 fractions (e.g. 123.45 or -123.45).
   291 
   292 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   293 interface with 'setup' command instead.
   294 
   295 * Command 'local_setup' is similar to 'setup', but operates on a local
   296 theory context.
   297 
   298 * The 'axiomatization' command now only works within a global theory
   299 context.  INCOMPATIBILITY.
   300 
   301 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   302 hypotheses.  Sorts required in the course of reasoning need to be
   303 covered by the constraints in the initial statement, completed by the
   304 type instance information of the background theory.  Non-trivial sort
   305 hypotheses, which rarely occur in practice, may be specified via
   306 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   307 
   308   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   309 
   310 The result contains an implicit sort hypotheses as before --
   311 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   312 normalization.
   313 
   314 * Generalized Isar history, with support for linear undo, direct state
   315 addressing etc.
   316 
   317 * Changed defaults for unify configuration options:
   318 
   319   unify_trace_bound = 50 (formerly 25)
   320   unify_search_bound = 60 (formerly 30)
   321 
   322 * Different bookkeeping for code equations (INCOMPATIBILITY):
   323 
   324   a) On theory merge, the last set of code equations for a particular
   325      constant is taken (in accordance with the policy applied by other
   326      parts of the code generator framework).
   327 
   328   b) Code equations stemming from explicit declarations (e.g. code
   329      attribute) gain priority over default code equations stemming
   330      from definition, primrec, fun etc.
   331 
   332 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   333 
   334 * Unified theorem tables for both code generators.  Thus [code
   335 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   336 
   337 * Command 'find_consts' searches for constants based on type and name
   338 patterns, e.g.
   339 
   340     find_consts "_ => bool"
   341 
   342 By default, matching is against subtypes, but it may be restricted to
   343 the whole type.  Searching by name is possible.  Multiple queries are
   344 conjunctive and queries may be negated by prefixing them with a
   345 hyphen:
   346 
   347     find_consts strict: "_ => bool" name: "Int" -"int => int"
   348 
   349 * New 'find_theorems' criterion "solves" matches theorems that
   350 directly solve the current goal (modulo higher-order unification).
   351 
   352 * Auto solve feature for main theorem statements: whenever a new goal
   353 is stated, "find_theorems solves" is called; any theorems that could
   354 solve the lemma directly are listed as part of the goal state.
   355 Cf. associated options in Proof General Isabelle settings menu,
   356 enabled by default, with reasonable timeout for pathological cases of
   357 higher-order unification.
   358 
   359 
   360 *** Document preparation ***
   361 
   362 * Antiquotation @{lemma} now imitates a regular terminal proof,
   363 demanding keyword 'by' and supporting the full method expression
   364 syntax just like the Isar command 'by'.
   365 
   366 
   367 *** HOL ***
   368 
   369 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   370 points Main and Complex_Main remain as before.
   371 
   372 * Logic image HOL-Plain provides a minimal HOL with the most important
   373 tools available (inductive, datatype, primrec, ...).  This facilitates
   374 experimentation and tool development.  Note that user applications
   375 (and library theories) should never refer to anything below theory
   376 Main, as before.
   377 
   378 * Logic image HOL-Main stops at theory Main, and thus facilitates
   379 experimentation due to shorter build times.
   380 
   381 * Logic image HOL-NSA contains theories of nonstandard analysis which
   382 were previously part of former HOL-Complex.  Entry point Hyperreal
   383 remains valid, but theories formerly using Complex_Main should now use
   384 new entry point Hypercomplex.
   385 
   386 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   387 Posix processes.  Avoids potentially expensive forking of the ML
   388 process.  New thread-based implementation also works on non-Unix
   389 platforms (Cygwin).  Provers are no longer hardwired, but defined
   390 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   391 commands are covered in the isar-ref manual.
   392 
   393 * Wrapper scripts for remote SystemOnTPTP service allows to use
   394 sledgehammer without local ATP installation (Vampire etc.). Other
   395 provers may be included via suitable ML wrappers, see also
   396 src/HOL/ATP_Linkup.thy.
   397 
   398 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   399 menu.
   400 
   401 * The metis method no longer fails because the theorem is too trivial
   402 (contains the empty clause).
   403 
   404 * The metis method now fails in the usual manner, rather than raising
   405 an exception, if it determines that it cannot prove the theorem.
   406 
   407 * Method "coherent" implements a prover for coherent logic (see also
   408 src/Tools/coherent.ML).
   409 
   410 * Constants "undefined" and "default" replace "arbitrary".  Usually
   411 "undefined" is the right choice to replace "arbitrary", though
   412 logically there is no difference.  INCOMPATIBILITY.
   413 
   414 * Command "value" now integrates different evaluation mechanisms.  The
   415 result of the first successful evaluation mechanism is printed.  In
   416 square brackets a particular named evaluation mechanisms may be
   417 specified (currently, [SML], [code] or [nbe]).  See further
   418 src/HOL/ex/Eval_Examples.thy.
   419 
   420 * Normalization by evaluation now allows non-leftlinear equations.
   421 Declare with attribute [code nbe].
   422 
   423 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   424 as the structured Isar versions "cases" and "induct", cf. the
   425 corresponding "cases" and "induct" attributes.  Mutual induction rules
   426 are now presented as a list of individual projections
   427 (e.g. foo_bar.inducts for types foo and bar); the old format with
   428 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   429 rare situations a different rule is selected --- notably nested tuple
   430 elimination instead of former prod.exhaust: use explicit (case_tac t
   431 rule: prod.exhaust) here.
   432 
   433 * Attributes "cases", "induct", "coinduct" support "del" option.
   434 
   435 * Removed fact "case_split_thm", which duplicates "case_split".
   436 
   437 * The option datatype has been moved to a new theory Option.  Renamed
   438 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   439 
   440 * New predicate "strict_mono" classifies strict functions on partial
   441 orders.  With strict functions on linear orders, reasoning about
   442 (in)equalities is facilitated by theorems "strict_mono_eq",
   443 "strict_mono_less_eq" and "strict_mono_less".
   444 
   445 * Some set operations are now proper qualified constants with
   446 authentic syntax.  INCOMPATIBILITY:
   447 
   448     op Int ~>   Set.Int
   449     op Un ~>    Set.Un
   450     INTER ~>    Set.INTER
   451     UNION ~>    Set.UNION
   452     Inter ~>    Set.Inter
   453     Union ~>    Set.Union
   454     {} ~>       Set.empty
   455     UNIV ~>     Set.UNIV
   456 
   457 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   458 theory Set.
   459 
   460 * Auxiliary class "itself" has disappeared -- classes without any
   461 parameter are treated as expected by the 'class' command.
   462 
   463 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   464 
   465 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   466 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   467 
   468 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   469 method "approximation".  It proves formulas on real values by using
   470 interval arithmetic.  In the formulas are also the transcendental
   471 functions sin, cos, tan, atan, ln, exp and the constant pi are
   472 allowed. For examples see
   473 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   474 
   475 * Theory "Reflection" now resides in HOL/Library.
   476 
   477 * Entry point to Word library now simply named "Word".
   478 INCOMPATIBILITY.
   479 
   480 * Made source layout more coherent with logical distribution
   481 structure:
   482 
   483     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   484     src/HOL/Library/Code_Message.thy ~> src/HOL/
   485     src/HOL/Library/GCD.thy ~> src/HOL/
   486     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   487     src/HOL/Library/Parity.thy ~> src/HOL/
   488     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   489     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   490     src/HOL/Real/Lubs.thy ~> src/HOL/
   491     src/HOL/Real/PReal.thy ~> src/HOL/
   492     src/HOL/Real/Rational.thy ~> src/HOL/
   493     src/HOL/Real/RComplete.thy ~> src/HOL/
   494     src/HOL/Real/RealDef.thy ~> src/HOL/
   495     src/HOL/Real/RealPow.thy ~> src/HOL/
   496     src/HOL/Real/Real.thy ~> src/HOL/
   497     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   498     src/HOL/Complex/Complex.thy ~> src/HOL/
   499     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   500     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   501     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   502     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   503     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   504     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   505     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   506     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   507     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   508     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   509     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   510     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   511     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   512     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   513     src/HOL/Real/Float ~> src/HOL/Library/
   514     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   515     src/HOL/Real/RealVector.thy ~> src/HOL/
   516 
   517     src/HOL/arith_data.ML ~> src/HOL/Tools
   518     src/HOL/hologic.ML ~> src/HOL/Tools
   519     src/HOL/simpdata.ML ~> src/HOL/Tools
   520     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   521     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   522     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   523     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   524     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   525     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   526     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   527 
   528     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   529     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   530     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   531     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   532     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   533     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   534 
   535 * If methods "eval" and "evaluation" encounter a structured proof
   536 state with !!/==>, only the conclusion is evaluated to True (if
   537 possible), avoiding strange error messages.
   538 
   539 * Method "sizechange" automates termination proofs using (a
   540 modification of) the size-change principle.  Requires SAT solver.  See
   541 src/HOL/ex/Termination.thy for examples.
   542 
   543 * Simplifier: simproc for let expressions now unfolds if bound
   544 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   545 
   546 * Method "arith": Linear arithmetic now ignores all inequalities when
   547 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   548 
   549 * New attribute "arith" for facts that should always be used
   550 automatically by arithmetic. It is intended to be used locally in
   551 proofs, e.g.
   552 
   553   assumes [arith]: "x > 0"
   554 
   555 Global usage is discouraged because of possible performance impact.
   556 
   557 * New classes "top" and "bot" with corresponding operations "top" and
   558 "bot" in theory Orderings; instantiation of class "complete_lattice"
   559 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   560 
   561 * Changed definition lemma "less_fun_def" in order to provide an
   562 instance for preorders on functions; use lemma "less_le" instead.
   563 INCOMPATIBILITY.
   564 
   565 * Theory Orderings: class "wellorder" moved here, with explicit
   566 induction rule "less_induct" as assumption.  For instantiation of
   567 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   568 INCOMPATIBILITY.
   569 
   570 * Theory Orderings: added class "preorder" as superclass of "order".
   571 INCOMPATIBILITY: Instantiation proofs for order, linorder
   572 etc. slightly changed.  Some theorems named order_class.* now named
   573 preorder_class.*.
   574 
   575 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   576 "diag" to "Id_on".
   577 
   578 * Theory Finite_Set: added a new fold combinator of type
   579 
   580   ('a => 'b => 'b) => 'b => 'a set => 'b
   581 
   582 Occasionally this is more convenient than the old fold combinator
   583 which is now defined in terms of the new one and renamed to
   584 fold_image.
   585 
   586 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   587 and "ring_simps" have been replaced by "algebra_simps" (which can be
   588 extended with further lemmas!).  At the moment both still exist but
   589 the former will disappear at some point.
   590 
   591 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   592 class recpower.  Type-specific simp rules for various recpower types
   593 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   594 
   595 rat_power_0    -> power_0
   596 rat_power_Suc  -> power_Suc
   597 realpow_0      -> power_0
   598 realpow_Suc    -> power_Suc
   599 complexpow_0   -> power_0
   600 complexpow_Suc -> power_Suc
   601 power_poly_0   -> power_0
   602 power_poly_Suc -> power_Suc
   603 
   604 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   605 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   606 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   607 of lemmas from Divides has been generalized from nat to class
   608 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   609 renames resulting from duplicate elimination:
   610 
   611     dvd_def_mod ~>          dvd_eq_mod_eq_0
   612     zero_dvd_iff ~>         dvd_0_left_iff
   613     dvd_0 ~>                dvd_0_right
   614     DIVISION_BY_ZERO_DIV ~> div_by_0
   615     DIVISION_BY_ZERO_MOD ~> mod_by_0
   616     mult_div ~>             div_mult_self2_is_id
   617     mult_mod ~>             mod_mult_self2_is_0
   618 
   619 * Theory IntDiv: removed many lemmas that are instances of class-based
   620 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   621 rename old lemmas as follows:
   622 
   623 dvd_diff               -> nat_dvd_diff
   624 dvd_zminus_iff         -> dvd_minus_iff
   625 mod_add1_eq            -> mod_add_eq
   626 mod_mult1_eq           -> mod_mult_right_eq
   627 mod_mult1_eq'          -> mod_mult_left_eq
   628 mod_mult_distrib_mod   -> mod_mult_eq
   629 nat_mod_add_left_eq    -> mod_add_left_eq
   630 nat_mod_add_right_eq   -> mod_add_right_eq
   631 nat_mod_div_trivial    -> mod_div_trivial
   632 nat_mod_mod_trivial    -> mod_mod_trivial
   633 zdiv_zadd_self1        -> div_add_self1
   634 zdiv_zadd_self2        -> div_add_self2
   635 zdiv_zmult_self1       -> div_mult_self2_is_id
   636 zdiv_zmult_self2       -> div_mult_self1_is_id
   637 zdvd_triv_left         -> dvd_triv_left
   638 zdvd_triv_right        -> dvd_triv_right
   639 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   640 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   641 zmod_zadd_left_eq      -> mod_add_left_eq
   642 zmod_zadd_right_eq     -> mod_add_right_eq
   643 zmod_zadd_self1        -> mod_add_self1
   644 zmod_zadd_self2        -> mod_add_self2
   645 zmod_zadd1_eq          -> mod_add_eq
   646 zmod_zdiff1_eq         -> mod_diff_eq
   647 zmod_zdvd_zmod         -> mod_mod_cancel
   648 zmod_zmod_cancel       -> mod_mod_cancel
   649 zmod_zmult_self1       -> mod_mult_self2_is_0
   650 zmod_zmult_self2       -> mod_mult_self1_is_0
   651 zmod_1                 -> mod_by_1
   652 zdiv_1                 -> div_by_1
   653 zdvd_abs1              -> abs_dvd_iff
   654 zdvd_abs2              -> dvd_abs_iff
   655 zdvd_refl              -> dvd_refl
   656 zdvd_trans             -> dvd_trans
   657 zdvd_zadd              -> dvd_add
   658 zdvd_zdiff             -> dvd_diff
   659 zdvd_zminus_iff        -> dvd_minus_iff
   660 zdvd_zminus2_iff       -> minus_dvd_iff
   661 zdvd_zmultD            -> dvd_mult_right
   662 zdvd_zmultD2           -> dvd_mult_left
   663 zdvd_zmult_mono        -> mult_dvd_mono
   664 zdvd_0_right           -> dvd_0_right
   665 zdvd_0_left            -> dvd_0_left_iff
   666 zdvd_1_left            -> one_dvd
   667 zminus_dvd_iff         -> minus_dvd_iff
   668 
   669 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   670 
   671 * The real numbers offer decimal input syntax: 12.34 is translated
   672 into 1234/10^2. This translation is not reversed upon output.
   673 
   674 * Theory Library/Polynomial defines an abstract type 'a poly of
   675 univariate polynomials with coefficients of type 'a.  In addition to
   676 the standard ring operations, it also supports div and mod.  Code
   677 generation is also supported, using list-style constructors.
   678 
   679 * Theory Library/Inner_Product defines a class of real_inner for real
   680 inner product spaces, with an overloaded operation inner :: 'a => 'a
   681 => real.  Class real_inner is a subclass of real_normed_vector from
   682 theory RealVector.
   683 
   684 * Theory Library/Product_Vector provides instances for the product
   685 type 'a * 'b of several classes from RealVector and Inner_Product.
   686 Definitions of addition, subtraction, scalar multiplication, norms,
   687 and inner products are included.
   688 
   689 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   690 addition to the field operations, numerals and case syntax are also
   691 supported.
   692 
   693 * Theory Library/Diagonalize provides constructive version of Cantor's
   694 first diagonalization argument.
   695 
   696 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   697 zlcm (for int); carried together from various gcd/lcm developements in
   698 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   699 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   700 may recover tupled syntax as follows:
   701 
   702     hide (open) const gcd
   703     abbreviation gcd where
   704       "gcd == (%(a, b). GCD.gcd a b)"
   705     notation (output)
   706       GCD.gcd ("gcd '(_, _')")
   707 
   708 The same works for lcm, zgcd, zlcm.
   709 
   710 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   711 instantiations for algebraic structures.  Removed some duplicate
   712 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   713 
   714 * ML antiquotation @{code} takes a constant as argument and generates
   715 corresponding code in background and inserts name of the corresponding
   716 resulting ML value/function/datatype constructor binding in place.
   717 All occurrences of @{code} with a single ML block are generated
   718 simultaneously.  Provides a generic and safe interface for
   719 instrumentalizing code generation.  See
   720 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   721 In future you ought to refrain from ad-hoc compiling generated SML
   722 code on the ML toplevel.  Note that (for technical reasons) @{code}
   723 cannot refer to constants for which user-defined serializations are
   724 set.  Refer to the corresponding ML counterpart directly in that
   725 cases.
   726 
   727 * Command 'rep_datatype': instead of theorem names the command now
   728 takes a list of terms denoting the constructors of the type to be
   729 represented as datatype.  The characteristic theorems have to be
   730 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   731 have disappeared in favour of existing ones:
   732 
   733     unit_induct                 ~> unit.induct
   734     prod_induct                 ~> prod.induct
   735     sum_induct                  ~> sum.induct
   736     Suc_Suc_eq                  ~> nat.inject
   737     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   738 
   739 
   740 *** HOL-Algebra ***
   741 
   742 * New locales for orders and lattices where the equivalence relation
   743 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   744 locales use a record structure with field eq for the equivalence.
   745 
   746 * New theory of factorial domains.
   747 
   748 * Units_l_inv and Units_r_inv are now simp rules by default.
   749 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   750 and/or r_inv will now also require deletion of these lemmas.
   751 
   752 * Renamed the following theorems, INCOMPATIBILITY:
   753 
   754 UpperD ~> Upper_memD
   755 LowerD ~> Lower_memD
   756 least_carrier ~> least_closed
   757 greatest_carrier ~> greatest_closed
   758 greatest_Lower_above ~> greatest_Lower_below
   759 one_zero ~> carrier_one_zero
   760 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   761 
   762 
   763 *** HOL-Nominal ***
   764 
   765 * Nominal datatypes can now contain type-variables.
   766 
   767 * Commands 'nominal_inductive' and 'equivariance' work with local
   768 theory targets.
   769 
   770 * Nominal primrec can now works with local theory targets and its
   771 specification syntax now conforms to the general format as seen in
   772 'inductive' etc.
   773 
   774 * Method "perm_simp" honours the standard simplifier attributes
   775 (no_asm), (no_asm_use) etc.
   776 
   777 * The new predicate #* is defined like freshness, except that on the
   778 left hand side can be a set or list of atoms.
   779 
   780 * Experimental command 'nominal_inductive2' derives strong induction
   781 principles for inductive definitions.  In contrast to
   782 'nominal_inductive', which can only deal with a fixed number of
   783 binders, it can deal with arbitrary expressions standing for sets of
   784 atoms to be avoided.  The only inductive definition we have at the
   785 moment that needs this generalisation is the typing rule for Lets in
   786 the algorithm W:
   787 
   788  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   789  -----------------------------------------------------------------
   790          Gamma |- Let x be t1 in t2 : T2
   791 
   792 In this rule one wants to avoid all the binders that are introduced by
   793 "close Gamma T1".  We are looking for other examples where this
   794 feature might be useful.  Please let us know.
   795 
   796 
   797 *** HOLCF ***
   798 
   799 * Reimplemented the simplification procedure for proving continuity
   800 subgoals.  The new simproc is extensible; users can declare additional
   801 continuity introduction rules with the attribute [cont2cont].
   802 
   803 * The continuity simproc now uses a different introduction rule for
   804 solving continuity subgoals on terms with lambda abstractions.  In
   805 some rare cases the new simproc may fail to solve subgoals that the
   806 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   807 Potential INCOMPATIBILITY.
   808 
   809 * Command 'fixrec': specification syntax now conforms to the general
   810 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   811 examples.  INCOMPATIBILITY.
   812 
   813 
   814 *** ZF ***
   815 
   816 * Proof of Zorn's Lemma for partial orders.
   817 
   818 
   819 *** ML ***
   820 
   821 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   822 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   823 depends on multithreading, so timouts will not work before Poly/ML
   824 5.2.1!
   825 
   826 * High-level support for concurrent ML programming, see
   827 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   828 particularly convenient to organize independent functional
   829 computations.  The concept of "synchronized variables" provides a
   830 higher-order interface for components with shared state, avoiding the
   831 delicate details of mutexes and condition variables.  (Requires
   832 Poly/ML 5.2.1 or later.)
   833 
   834 * ML bindings produced via Isar commands are stored within the Isar
   835 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   836 become thread-safe and work with undo as expected (concerning
   837 top-level bindings, not side-effects on global references).
   838 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   839 compiler at runtime; really global bindings need to be given outside a
   840 theory.  (Requires Poly/ML 5.2 or later.)
   841 
   842 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   843 context.  Top-level ML bindings are stored within the proof context in
   844 a purely sequential fashion, disregarding the nested proof structure.
   845 ML bindings introduced by 'ML_prf' are discarded at the end of the
   846 proof.  (Requires Poly/ML 5.2 or later.)
   847 
   848 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   849 and Method.setup, as well as Isar commands 'attribute_setup' and
   850 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   851 existing code accordingly, or use plain 'setup' together with old
   852 Method.add_method.
   853 
   854 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   855 to 'a -> thm, while results are always tagged with an authentic oracle
   856 name.  The Isar command 'oracle' is now polymorphic, no argument type
   857 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   858 accordingly.  Note that extra performance may be gained by producing
   859 the cterm carefully, avoiding slow Thm.cterm_of.
   860 
   861 * Simplified interface for defining document antiquotations via
   862 ThyOutput.antiquotation, ThyOutput.output, and optionally
   863 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   864 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   865 examples.
   866 
   867 * More systematic treatment of long names, abstract name bindings, and
   868 name space operations.  Basic operations on qualified names have been
   869 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   870 Long_Name.append.  Old type bstring has been mostly replaced by
   871 abstract type binding (see structure Binding), which supports precise
   872 qualification by packages and local theory targets, as well as proper
   873 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   874 bstring values into Binding.name, or better pass through abstract
   875 bindings everywhere.  See further src/Pure/General/long_name.ML,
   876 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   877 
   878 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   879 LocalTheory.note etc.) now refer to the *full* internal name, not the
   880 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   881 
   882 * Disposed old type and term read functions (Sign.read_def_typ,
   883 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   884 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   885 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   886 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   887 resort for legacy applications.
   888 
   889 * Disposed old declarations, tactics, tactic combinators that refer to
   890 the simpset or claset of an implicit theory (such as Addsimps,
   891 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   892 embedded ML text, or local_simpset_of with a proper context passed as
   893 explicit runtime argument.
   894 
   895 * Rules and tactics that read instantiations (read_instantiate,
   896 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   897 context, which is required for parsing and type-checking.  Moreover,
   898 the variables are specified as plain indexnames, not string encodings
   899 thereof.  INCOMPATIBILITY.
   900 
   901 * Generic Toplevel.add_hook interface allows to analyze the result of
   902 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   903 for theorem dependency output of transactions resulting in a new
   904 theory state.
   905 
   906 * ML antiquotations: block-structured compilation context indicated by
   907 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   908 
   909   @{binding name}                         - basic name binding
   910   @{let ?pat = term}                      - term abbreviation (HO matching)
   911   @{note name = fact}                     - fact abbreviation
   912   @{thm fact}                             - singleton fact (with attributes)
   913   @{thms fact}                            - general fact (with attributes)
   914   @{lemma prop by method}                 - singleton goal
   915   @{lemma prop by meth1 meth2}            - singleton goal
   916   @{lemma prop1 ... propN by method}      - general goal
   917   @{lemma prop1 ... propN by meth1 meth2} - general goal
   918   @{lemma (open) ...}                     - open derivation
   919 
   920 
   921 *** System ***
   922 
   923 * The Isabelle "emacs" tool provides a specific interface to invoke
   924 Proof General / Emacs, with more explicit failure if that is not
   925 installed (the old isabelle-interface script silently falls back on
   926 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   927 installation location of the Proof General distribution.
   928 
   929 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   930 the Isabelle process into a JVM/Scala application.  See
   931 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   932 process wrapper has been discontinued.)
   933 
   934 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   935 
   936 * Various status messages (with exact source position information) are
   937 emitted, if proper markup print mode is enabled.  This allows
   938 user-interface components to provide detailed feedback on internal
   939 prover operations.
   940 
   941 
   942 
   943 New in Isabelle2008 (June 2008)
   944 -------------------------------
   945 
   946 *** General ***
   947 
   948 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   949 and updated, with formally checked references as hyperlinks.
   950 
   951 * Theory loader: use_thy (and similar operations) no longer set the
   952 implicit ML context, which was occasionally hard to predict and in
   953 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   954 provides a proper context already.
   955 
   956 * Theory loader: old-style ML proof scripts being *attached* to a thy
   957 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   958 'use' within a theory file will do the job.
   959 
   960 * Name space merge now observes canonical order, i.e. the second space
   961 is inserted into the first one, while existing entries in the first
   962 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   963 swap theory imports.
   964 
   965 * Syntax: symbol \<chi> is now considered a letter.  Potential
   966 INCOMPATIBILITY in identifier syntax etc.
   967 
   968 * Outer syntax: string tokens no longer admit escaped white space,
   969 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   970 white space without escapes.
   971 
   972 * Outer syntax: string tokens may contain arbitrary character codes
   973 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   974 "foo_bar".
   975 
   976 
   977 *** Pure ***
   978 
   979 * Context-dependent token translations.  Default setup reverts locally
   980 fixed variables, and adds hilite markup for undeclared frees.
   981 
   982 * Unused theorems can be found using the new command 'unused_thms'.
   983 There are three ways of invoking it:
   984 
   985 (1) unused_thms
   986      Only finds unused theorems in the current theory.
   987 
   988 (2) unused_thms thy_1 ... thy_n -
   989      Finds unused theorems in the current theory and all of its ancestors,
   990      excluding the theories thy_1 ... thy_n and all of their ancestors.
   991 
   992 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   993      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   994      their ancestors, excluding the theories thy_1 ... thy_n and all of
   995      their ancestors.
   996 
   997 In order to increase the readability of the list produced by
   998 unused_thms, theorems that have been created by a particular instance
   999 of a theory command such as 'inductive' or 'function' are considered
  1000 to belong to the same "group", meaning that if at least one theorem in
  1001 this group is used, the other theorems in the same group are no longer
  1002 reported as unused.  Moreover, if all theorems in the group are
  1003 unused, only one theorem in the group is displayed.
  1004 
  1005 Note that proof objects have to be switched on in order for
  1006 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1007 usually the case when using Proof General with the default settings).
  1008 
  1009 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1010 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1011 duplicate fact bindings, or even accidental fact duplications.  Note
  1012 that tools may maintain dynamically scoped facts systematically, using
  1013 PureThy.add_thms_dynamic.
  1014 
  1015 * Command 'hide' now allows to hide from "fact" name space as well.
  1016 
  1017 * Eliminated destructive theorem database, simpset, claset, and
  1018 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1019 update of theories within ML code.
  1020 
  1021 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1022 INCOMPATIBILITY, object-logics depending on former Pure require
  1023 additional setup PureThy.old_appl_syntax_setup; object-logics
  1024 depending on former CPure need to refer to Pure.
  1025 
  1026 * Commands 'use' and 'ML' are now purely functional, operating on
  1027 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1028 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1029 INCOMPATIBILITY.
  1030 
  1031 * Command 'setup': discontinued implicit version with ML reference.
  1032 
  1033 * Instantiation target allows for simultaneous specification of class
  1034 instance operations together with an instantiation proof.
  1035 Type-checking phase allows to refer to class operations uniformly.
  1036 See src/HOL/Complex/Complex.thy for an Isar example and
  1037 src/HOL/Library/Eval.thy for an ML example.
  1038 
  1039 * Indexing of literal facts: be more serious about including only
  1040 facts from the visible specification/proof context, but not the
  1041 background context (locale etc.).  Affects `prop` notation and method
  1042 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1043 situations.
  1044 
  1045 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1046 "(open)" option, which used to expose internal bound variables to the
  1047 proof text.
  1048 
  1049 * Isar statements: removed obsolete case "rule_context".
  1050 INCOMPATIBILITY, better use explicit fixes/assumes.
  1051 
  1052 * Locale proofs: default proof step now includes 'unfold_locales';
  1053 hence 'proof' without argument may be used to unfold locale
  1054 predicates.
  1055 
  1056 
  1057 *** Document preparation ***
  1058 
  1059 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1060 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1061 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1062 spot); renamed link color from "darkblue" to "linkcolor" (default
  1063 value unchanged, can be redefined via \definecolor); no longer sets
  1064 "a4paper" option (unnecessary or even intrusive).
  1065 
  1066 * Antiquotation @{lemma A method} proves proposition A by the given
  1067 method (either a method name or a method name plus (optional) method
  1068 arguments in parentheses) and prints A just like @{prop A}.
  1069 
  1070 
  1071 *** HOL ***
  1072 
  1073 * New primrec package.  Specification syntax conforms in style to
  1074 definition/function/....  No separate induction rule is provided.  The
  1075 "primrec" command distinguishes old-style and new-style specifications
  1076 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1077 When adjusting theories, beware: constants stemming from new-style
  1078 primrec specifications have authentic syntax.
  1079 
  1080 * Metis prover is now an order of magnitude faster, and also works
  1081 with multithreading.
  1082 
  1083 * Metis: the maximum number of clauses that can be produced from a
  1084 theorem is now given by the attribute max_clauses.  Theorems that
  1085 exceed this number are ignored, with a warning printed.
  1086 
  1087 * Sledgehammer no longer produces structured proofs by default. To
  1088 enable, declare [[sledgehammer_full = true]].  Attributes
  1089 reconstruction_modulus, reconstruction_sorts renamed
  1090 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1091 
  1092 * Method "induct_scheme" derives user-specified induction rules
  1093 from well-founded induction and completeness of patterns. This factors
  1094 out some operations that are done internally by the function package
  1095 and makes them available separately.  See
  1096 src/HOL/ex/Induction_Scheme.thy for examples.
  1097 
  1098 * More flexible generation of measure functions for termination
  1099 proofs: Measure functions can be declared by proving a rule of the
  1100 form "is_measure f" and giving it the [measure_function] attribute.
  1101 The "is_measure" predicate is logically meaningless (always true), and
  1102 just guides the heuristic.  To find suitable measure functions, the
  1103 termination prover sets up the goal "is_measure ?f" of the appropriate
  1104 type and generates all solutions by prolog-style backwards proof using
  1105 the declared rules.
  1106 
  1107 This setup also deals with rules like 
  1108 
  1109   "is_measure f ==> is_measure (list_size f)"
  1110 
  1111 which accommodates nested datatypes that recurse through lists.
  1112 Similar rules are predeclared for products and option types.
  1113 
  1114 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1115 
  1116   INCOMPATIBILITIES:
  1117 
  1118   - Definitions of overloaded constants on sets have to be replaced by
  1119     definitions on => and bool.
  1120 
  1121   - Some definitions of overloaded operators on sets can now be proved
  1122     using the definitions of the operators on => and bool.  Therefore,
  1123     the following theorems have been renamed:
  1124 
  1125       subset_def   -> subset_eq
  1126       psubset_def  -> psubset_eq
  1127       set_diff_def -> set_diff_eq
  1128       Compl_def    -> Compl_eq
  1129       Sup_set_def  -> Sup_set_eq
  1130       Inf_set_def  -> Inf_set_eq
  1131       sup_set_def  -> sup_set_eq
  1132       inf_set_def  -> inf_set_eq
  1133 
  1134   - Due to the incompleteness of the HO unification algorithm, some
  1135     rules such as subst may require manual instantiation, if some of
  1136     the unknowns in the rule is a set.
  1137 
  1138   - Higher order unification and forward proofs:
  1139     The proof pattern
  1140 
  1141       have "P (S::'a set)" <...>
  1142       then have "EX S. P S" ..
  1143 
  1144     no longer works (due to the incompleteness of the HO unification
  1145     algorithm) and must be replaced by the pattern
  1146 
  1147       have "EX S. P S"
  1148       proof
  1149         show "P S" <...>
  1150       qed
  1151 
  1152   - Calculational reasoning with subst (or similar rules):
  1153     The proof pattern
  1154 
  1155       have "P (S::'a set)" <...>
  1156       also have "S = T" <...>
  1157       finally have "P T" .
  1158 
  1159     no longer works (for similar reasons as the previous example) and
  1160     must be replaced by something like
  1161 
  1162       have "P (S::'a set)" <...>
  1163       moreover have "S = T" <...>
  1164       ultimately have "P T" by simp
  1165 
  1166   - Tactics or packages written in ML code:
  1167     Code performing pattern matching on types via
  1168 
  1169       Type ("set", [T]) => ...
  1170 
  1171     must be rewritten. Moreover, functions like strip_type or
  1172     binder_types no longer return the right value when applied to a
  1173     type of the form
  1174 
  1175       T1 => ... => Tn => U => bool
  1176 
  1177     rather than
  1178 
  1179       T1 => ... => Tn => U set
  1180 
  1181 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1182 Wellfounded_Relations to theory Wellfounded.
  1183 
  1184 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1185 
  1186 * Class finite no longer treats UNIV as class parameter.  Use class
  1187 enum from theory Library/Enum instead to achieve a similar effect.
  1188 INCOMPATIBILITY.
  1189 
  1190 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1191 and "Cons".  INCOMPATIBILITY.
  1192 
  1193 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1194 Potential INCOMPATIBILITY.
  1195 
  1196 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1197 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1198 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1199 
  1200 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1201 the same name in theory Orderings:
  1202 
  1203   less_trans
  1204   less_linear
  1205   le_imp_less_or_eq
  1206   le_less_trans
  1207   less_le_trans
  1208   less_not_sym
  1209   less_asym
  1210 
  1211 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1212 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1213 and different variable names.
  1214 
  1215 * Library/Option_ord.thy: Canonical order on option type.
  1216 
  1217 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1218 finite maps.
  1219 
  1220 * Library/Countable.thy: Type class for countable types.
  1221 
  1222 * Theory Int: The representation of numerals has changed.  The infix
  1223 operator BIT and the bit datatype with constructors B0 and B1 have
  1224 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1225 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1226 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1227 accordingly.
  1228 
  1229 * Theory Nat: definition of <= and < on natural numbers no longer
  1230 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1231 le_def and less_def have disappeared.  Consider lemmas not_less
  1232 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1233 
  1234 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1235 (whose purpose mainly is for various fold_set functionals) have been
  1236 abandoned in favor of the existing algebraic classes
  1237 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1238 lower_semilattice (resp. upper_semilattice) and linorder.
  1239 INCOMPATIBILITY.
  1240 
  1241 * Theory Transitive_Closure: induct and cases rules now declare proper
  1242 case_names ("base" and "step").  INCOMPATIBILITY.
  1243 
  1244 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1245 lattices.  The form set-specific version is available as
  1246 Inductive.lfp_ordinal_induct_set.
  1247 
  1248 * Renamed theorems "power.simps" to "power_int.simps".
  1249 INCOMPATIBILITY.
  1250 
  1251 * Class semiring_div provides basic abstract properties of semirings
  1252 with division and modulo operations.  Subsumes former class dvd_mod.
  1253 
  1254 * Merged theories IntDef, Numeral and IntArith into unified theory
  1255 Int.  INCOMPATIBILITY.
  1256 
  1257 * Theory Library/Code_Index: type "index" now represents natural
  1258 numbers rather than integers.  INCOMPATIBILITY.
  1259 
  1260 * New class "uminus" with operation "uminus" (split of from class
  1261 "minus" which now only has operation "minus", binary).
  1262 INCOMPATIBILITY.
  1263 
  1264 * Constants "card", "internal_split", "option_map" now with authentic
  1265 syntax.  INCOMPATIBILITY.
  1266 
  1267 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1268 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1269 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1270 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1271 Sup_set_def, le_def, less_def, option_map_def now with object
  1272 equality.  INCOMPATIBILITY.
  1273 
  1274 * Records. Removed K_record, and replaced it by pure lambda term
  1275 %x. c. The simplifier setup is now more robust against eta expansion.
  1276 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1277 
  1278 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1279 
  1280 * Library/ListVector: new theory of arithmetic vector operations.
  1281 
  1282 * Library/Order_Relation: new theory of various orderings as sets of
  1283 pairs.  Defines preorders, partial orders, linear orders and
  1284 well-orders on sets and on types.
  1285 
  1286 
  1287 *** ZF ***
  1288 
  1289 * Renamed some theories to allow to loading both ZF and HOL in the
  1290 same session:
  1291 
  1292   Datatype  -> Datatype_ZF
  1293   Inductive -> Inductive_ZF
  1294   Int       -> Int_ZF
  1295   IntDiv    -> IntDiv_ZF
  1296   Nat       -> Nat_ZF
  1297   List      -> List_ZF
  1298   Main      -> Main_ZF
  1299 
  1300 INCOMPATIBILITY: ZF theories that import individual theories below
  1301 Main might need to be adapted.  Regular theory Main is still
  1302 available, as trivial extension of Main_ZF.
  1303 
  1304 
  1305 *** ML ***
  1306 
  1307 * ML within Isar: antiquotation @{const name} or @{const
  1308 name(typargs)} produces statically-checked Const term.
  1309 
  1310 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1311 (of the same name).  Removed obsolete print command.
  1312 
  1313 * Removed obsolete "use_legacy_bindings" function.
  1314 
  1315 * The ``print mode'' is now a thread-local value derived from a global
  1316 template (the former print_mode reference), thus access becomes
  1317 non-critical.  The global print_mode reference is for session
  1318 management only; user-code should use print_mode_value,
  1319 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1320 
  1321 * Functions system/system_out provide a robust way to invoke external
  1322 shell commands, with propagation of interrupts (requires Poly/ML
  1323 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1324 
  1325 
  1326 *** System ***
  1327 
  1328 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1329 in accordance with Proof General 3.7, which prefers GNU emacs.
  1330 
  1331 * isatool tty runs Isabelle process with plain tty interaction;
  1332 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1333 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1334 
  1335 * isatool browser now works with Cygwin as well, using general
  1336 "javapath" function defined in Isabelle process environment.
  1337 
  1338 * YXML notation provides a simple and efficient alternative to
  1339 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1340 isatool yxml as described in the Isabelle system manual.
  1341 
  1342 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1343 provides general wrapper for managing an Isabelle process in a robust
  1344 fashion, with ``cooked'' output from stdin/stderr.
  1345 
  1346 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1347 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1348 
  1349 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1350 way of changing the user's settings is via
  1351 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1352 script.
  1353 
  1354 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1355 cores of the underlying machine, which is a good starting point for
  1356 optimal performance tuning.  The corresponding usedir option -M allows
  1357 "max" as an alias for "0".  WARNING: does not work on certain versions
  1358 of Mac OS (with Poly/ML 5.1).
  1359 
  1360 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1361 adverse effect of Isabelle flooding interactive front-ends (notably
  1362 ProofGeneral / XEmacs).
  1363 
  1364 
  1365 
  1366 New in Isabelle2007 (November 2007)
  1367 -----------------------------------
  1368 
  1369 *** General ***
  1370 
  1371 * More uniform information about legacy features, notably a
  1372 warning/error of "Legacy feature: ...", depending on the state of the
  1373 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1374 legacy features will disappear eventually.
  1375 
  1376 * Theory syntax: the header format ``theory A = B + C:'' has been
  1377 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1378 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1379 
  1380 * Theory syntax: the old non-Isar theory file format has been
  1381 discontinued altogether.  Note that ML proof scripts may still be used
  1382 with Isar theories; migration is usually quite simple with the ML
  1383 function use_legacy_bindings.  INCOMPATIBILITY.
  1384 
  1385 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1386 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1387 quotes.
  1388 
  1389 * Theory loader: be more serious about observing the static theory
  1390 header specifications (including optional directories), but not the
  1391 accidental file locations of previously successful loads.  The strict
  1392 update policy of former update_thy is now already performed by
  1393 use_thy, so the former has been removed; use_thys updates several
  1394 theories simultaneously, just as 'imports' within a theory header
  1395 specification, but without merging the results.  Potential
  1396 INCOMPATIBILITY: may need to refine theory headers and commands
  1397 ROOT.ML which depend on load order.
  1398 
  1399 * Theory loader: optional support for content-based file
  1400 identification, instead of the traditional scheme of full physical
  1401 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1402 (cf. the system manual).  The new scheme allows to work with
  1403 non-finished theories in persistent session images, such that source
  1404 files may be moved later on without requiring reloads.
  1405 
  1406 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1407 file (with the same base name as the theory) are considered a legacy
  1408 feature, which will disappear eventually. Even now, the theory loader
  1409 no longer maintains dependencies on such files.
  1410 
  1411 * Syntax: the scope for resolving ambiguities via type-inference is
  1412 now limited to individual terms, instead of whole simultaneous
  1413 specifications as before. This greatly reduces the complexity of the
  1414 syntax module and improves flexibility by separating parsing and
  1415 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1416 'fixes' etc.) are required in rare situations.
  1417 
  1418 * Syntax: constants introduced by new-style packages ('definition',
  1419 'abbreviation' etc.) are passed through the syntax module in
  1420 ``authentic mode''. This means that associated mixfix annotations
  1421 really stick to such constants, independently of potential name space
  1422 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1423 trees are represented slightly differently, may need to adapt syntax
  1424 translations accordingly. Use CONST marker in 'translations' and
  1425 @{const_syntax} antiquotation in 'parse_translation' etc.
  1426 
  1427 * Legacy goal package: reduced interface to the bare minimum required
  1428 to keep existing proof scripts running.  Most other user-level
  1429 functions are now part of the OldGoals structure, which is *not* open
  1430 by default (consider isatool expandshort before open OldGoals).
  1431 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1432 these tend to cause confusion about the actual goal (!) context being
  1433 used here, which is not necessarily the same as the_context().
  1434 
  1435 * Command 'find_theorems': supports "*" wild-card in "name:"
  1436 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1437 support a specific search form (see ProofGeneral/CHANGES).
  1438 
  1439 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1440 by default, which means that "prems" (and also "fixed variables") are
  1441 suppressed from proof state output.  Note that the ProofGeneral
  1442 settings mechanism allows to change and save options persistently, but
  1443 older versions of Isabelle will fail to start up if a negative prems
  1444 limit is imposed.
  1445 
  1446 * Local theory targets may be specified by non-nested blocks of
  1447 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1448 contain definitions, theorems etc., including any derived mechanism
  1449 that has been implemented on top of these primitives.  This concept
  1450 generalizes the existing ``theorem (in ...)'' towards more versatility
  1451 and scalability.
  1452 
  1453 * Proof General interface: proper undo of final 'end' command;
  1454 discontinued Isabelle/classic mode (ML proof scripts).
  1455 
  1456 
  1457 *** Document preparation ***
  1458 
  1459 * Added antiquotation @{theory name} which prints the given name,
  1460 after checking that it refers to a valid ancestor theory in the
  1461 current context.
  1462 
  1463 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1464 check the given source text as ML type/structure, printing verbatim.
  1465 
  1466 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1467 "c args == rhs" given in the current context.  (Any number of
  1468 arguments may be given on the LHS.)
  1469 
  1470 
  1471 *** Pure ***
  1472 
  1473 * The 'class' package offers a combination of axclass and locale to
  1474 achieve Haskell-like type classes in Isabelle.  Definitions and
  1475 theorems within a class context produce both relative results (with
  1476 implicit parameters according to the locale context), and polymorphic
  1477 constants with qualified polymorphism (according to the class
  1478 context).  Within the body context of a 'class' target, a separate
  1479 syntax layer ("user space type system") takes care of converting
  1480 between global polymorphic consts and internal locale representation.
  1481 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1482 "isatool doc classes" provides a tutorial.
  1483 
  1484 * Generic code generator framework allows to generate executable
  1485 code for ML and Haskell (including Isabelle classes).  A short usage
  1486 sketch:
  1487 
  1488     internal compilation:
  1489         export_code <list of constants (term syntax)> in SML
  1490     writing SML code to a file:
  1491         export_code <list of constants (term syntax)> in SML <filename>
  1492     writing OCaml code to a file:
  1493         export_code <list of constants (term syntax)> in OCaml <filename>
  1494     writing Haskell code to a bunch of files:
  1495         export_code <list of constants (term syntax)> in Haskell <filename>
  1496 
  1497     evaluating closed propositions to True/False using code generation:
  1498         method ``eval''
  1499 
  1500 Reasonable default setup of framework in HOL.
  1501 
  1502 Theorem attributs for selecting and transforming function equations theorems:
  1503 
  1504     [code fun]:        select a theorem as function equation for a specific constant
  1505     [code fun del]:    deselect a theorem as function equation for a specific constant
  1506     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1507     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1508 
  1509 User-defined serializations (target in {SML, OCaml, Haskell}):
  1510 
  1511     code_const <and-list of constants (term syntax)>
  1512       {(target) <and-list of const target syntax>}+
  1513 
  1514     code_type <and-list of type constructors>
  1515       {(target) <and-list of type target syntax>}+
  1516 
  1517     code_instance <and-list of instances>
  1518       {(target)}+
  1519         where instance ::= <type constructor> :: <class>
  1520 
  1521     code_class <and_list of classes>
  1522       {(target) <and-list of class target syntax>}+
  1523         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1524 
  1525 code_instance and code_class only are effective to target Haskell.
  1526 
  1527 For example usage see src/HOL/ex/Codegenerator.thy and
  1528 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1529 generation from Isabelle/HOL theories is available via "isatool doc
  1530 codegen".
  1531 
  1532 * Code generator: consts in 'consts_code' Isar commands are now
  1533 referred to by usual term syntax (including optional type
  1534 annotations).
  1535 
  1536 * Command 'no_translations' removes translation rules from theory
  1537 syntax.
  1538 
  1539 * Overloaded definitions are now actually checked for acyclic
  1540 dependencies.  The overloading scheme is slightly more general than
  1541 that of Haskell98, although Isabelle does not demand an exact
  1542 correspondence to type class and instance declarations.
  1543 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1544 exotic versions of overloading -- at the discretion of the user!
  1545 
  1546 Polymorphic constants are represented via type arguments, i.e. the
  1547 instantiation that matches an instance against the most general
  1548 declaration given in the signature.  For example, with the declaration
  1549 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1550 as c(nat).  Overloading is essentially simultaneous structural
  1551 recursion over such type arguments.  Incomplete specification patterns
  1552 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1553 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1554 Command 'print_theory' outputs the normalized system of recursive
  1555 equations, see section "definitions".
  1556 
  1557 * Configuration options are maintained within the theory or proof
  1558 context (with name and type bool/int/string), providing a very simple
  1559 interface to a poor-man's version of general context data.  Tools may
  1560 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1561 these values using Config.get etc.  Users may change options via an
  1562 associated attribute of the same name.  This form of context
  1563 declaration works particularly well with commands 'declare' or
  1564 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1565 very easy to avoid global references, which would not observe Isar
  1566 toplevel undo/redo and fail to work with multithreading.
  1567 
  1568 Various global ML references of Pure and HOL have been turned into
  1569 configuration options:
  1570 
  1571   Unify.search_bound		unify_search_bound
  1572   Unify.trace_bound		unify_trace_bound
  1573   Unify.trace_simp		unify_trace_simp
  1574   Unify.trace_types		unify_trace_types
  1575   Simplifier.simp_depth_limit	simp_depth_limit
  1576   Blast.depth_limit		blast_depth_limit
  1577   DatatypeProp.dtK		datatype_distinctness_limit
  1578   fast_arith_neq_limit  	fast_arith_neq_limit
  1579   fast_arith_split_limit	fast_arith_split_limit
  1580 
  1581 * Named collections of theorems may be easily installed as context
  1582 data using the functor NamedThmsFun (see also
  1583 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1584 attributes; there is also a toplevel print command.  This facility is
  1585 just a common case of general context data, which is the preferred way
  1586 for anything more complex than just a list of facts in canonical
  1587 order.
  1588 
  1589 * Isar: command 'declaration' augments a local theory by generic
  1590 declaration functions written in ML.  This enables arbitrary content
  1591 being added to the context, depending on a morphism that tells the
  1592 difference of the original declaration context wrt. the application
  1593 context encountered later on.
  1594 
  1595 * Isar: proper interfaces for simplification procedures.  Command
  1596 'simproc_setup' declares named simprocs (with match patterns, and body
  1597 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1598 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1599 
  1600 * Isar: an extra pair of brackets around attribute declarations
  1601 abbreviates a theorem reference involving an internal dummy fact,
  1602 which will be ignored later --- only the effect of the attribute on
  1603 the background context will persist.  This form of in-place
  1604 declarations is particularly useful with commands like 'declare' and
  1605 'using', for example ``have A using [[simproc a]] by simp''.
  1606 
  1607 * Isar: method "assumption" (and implicit closing of subproofs) now
  1608 takes simple non-atomic goal assumptions into account: after applying
  1609 an assumption as a rule the resulting subgoals are solved by atomic
  1610 assumption steps.  This is particularly useful to finish 'obtain'
  1611 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1612 without referring to the original premise "!!x. P x ==> thesis" in the
  1613 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1614 more permissive.
  1615 
  1616 * Isar: implicit use of prems from the Isar proof context is
  1617 considered a legacy feature.  Common applications like ``have A .''
  1618 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1619 referencing facts explicitly here improves readability and
  1620 maintainability of proof texts.
  1621 
  1622 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1623 the obtained context from the course of reasoning!  For example:
  1624 
  1625   assume "EX x y. A x & B y"   -- "any previous fact"
  1626   then guess x and y by clarify
  1627 
  1628 This technique is potentially adventurous, depending on the facts and
  1629 proof tools being involved here.
  1630 
  1631 * Isar: known facts from the proof context may be specified as literal
  1632 propositions, using ASCII back-quote syntax.  This works wherever
  1633 named facts used to be allowed so far, in proof commands, proof
  1634 methods, attributes etc.  Literal facts are retrieved from the context
  1635 according to unification of type and term parameters.  For example,
  1636 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1637 theorems in the current context, then these are valid literal facts:
  1638 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1639 
  1640 There is also a proof method "fact" which does the same composition
  1641 for explicit goal states, e.g. the following proof texts coincide with
  1642 certain special cases of literal facts:
  1643 
  1644   have "A" by fact                 ==  note `A`
  1645   have "A ==> B" by fact           ==  note `A ==> B`
  1646   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1647   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1648 
  1649 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1650 outer syntax.  Thus symbolic identifiers may be used without
  1651 additional white space in declarations like this: ``assume *: A''.
  1652 
  1653 * Isar: 'print_facts' prints all local facts of the current context,
  1654 both named and unnamed ones.
  1655 
  1656 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1657 
  1658   def x == "t" and y == "u"
  1659 
  1660 * Isar: added command 'unfolding', which is structurally similar to
  1661 'using', but affects both the goal state and facts by unfolding given
  1662 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1663 'unfolded' attribute may be replaced by first-class proof text.
  1664 
  1665 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1666 and command 'unfolding' now all support object-level equalities
  1667 (potentially conditional).  The underlying notion of rewrite rule is
  1668 analogous to the 'rule_format' attribute, but *not* that of the
  1669 Simplifier (which is usually more generous).
  1670 
  1671 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1672 premises of a theorem by n. Useful in conjunction with drule.
  1673 
  1674 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1675 method expression within a sandbox consisting of the first N
  1676 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1677 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1678 simplifies all new goals that emerge from applying rule foo to the
  1679 originally first one.
  1680 
  1681 * Isar: schematic goals are no longer restricted to higher-order
  1682 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1683 expected.
  1684 
  1685 * Isar: the conclusion of a long theorem statement is now either
  1686 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1687 (essentially a disjunction of cases with local parameters and
  1688 assumptions).  The latter allows to express general elimination rules
  1689 adequately; in this notation common elimination rules look like this:
  1690 
  1691   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1692     assumes "EX x. P x"
  1693     obtains x where "P x"
  1694 
  1695   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1696     assumes "A & B"
  1697     obtains A and B
  1698 
  1699   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1700     assumes "A | B"
  1701     obtains
  1702       A
  1703     | B
  1704 
  1705 The subsequent classical rules even refer to the formal "thesis"
  1706 explicitly:
  1707 
  1708   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1709     obtains "~ thesis"
  1710 
  1711   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1712     obtains "thesis ==> something"
  1713 
  1714 The actual proof of an 'obtains' statement is analogous to that of the
  1715 Isar proof element 'obtain', only that there may be several cases.
  1716 Optional case names may be specified in parentheses; these will be
  1717 available both in the present proof and as annotations in the
  1718 resulting rule, for later use with the 'cases' method (cf. attribute
  1719 case_names).
  1720 
  1721 * Isar: the assumptions of a long theorem statement are available as
  1722 "assms" fact in the proof context.  This is more appropriate than the
  1723 (historical) "prems", which refers to all assumptions of the current
  1724 context, including those from the target locale, proof body etc.
  1725 
  1726 * Isar: 'print_statement' prints theorems from the current theory or
  1727 proof context in long statement form, according to the syntax of a
  1728 top-level lemma.
  1729 
  1730 * Isar: 'obtain' takes an optional case name for the local context
  1731 introduction rule (default "that").
  1732 
  1733 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1734 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1735 to occur.
  1736 
  1737 * Pure: syntax "CONST name" produces a fully internalized constant
  1738 according to the current context.  This is particularly useful for
  1739 syntax translations that should refer to internal constant
  1740 representations independently of name spaces.
  1741 
  1742 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1743 instead of "FOO ". This allows multiple binder declarations to coexist
  1744 in the same context.  INCOMPATIBILITY.
  1745 
  1746 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1747 primitive that also works in a locale context (both for constants and
  1748 fixed variables). Type declaration and internal syntactic representation
  1749 of given constants retrieved from the context. Likewise, the
  1750 'no_notation' command allows to remove given syntax annotations from the
  1751 current context.
  1752 
  1753 * Isar/locales: new derived specification elements 'axiomatization',
  1754 'definition', 'abbreviation', which support type-inference, admit
  1755 object-level specifications (equality, equivalence).  See also the
  1756 isar-ref manual.  Examples:
  1757 
  1758   axiomatization
  1759     eq  (infix "===" 50) where
  1760     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1761 
  1762   definition "f x y = x + y + 1"
  1763   definition g where "g x = f x x"
  1764 
  1765   abbreviation
  1766     neq  (infix "=!=" 50) where
  1767     "x =!= y == ~ (x === y)"
  1768 
  1769 These specifications may be also used in a locale context.  Then the
  1770 constants being introduced depend on certain fixed parameters, and the
  1771 constant name is qualified by the locale base name.  An internal
  1772 abbreviation takes care for convenient input and output, making the
  1773 parameters implicit and using the original short name.  See also
  1774 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1775 entities from a monomorphic theory.
  1776 
  1777 Presently, abbreviations are only available 'in' a target locale, but
  1778 not inherited by general import expressions.  Also note that
  1779 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1780 'translations' in common applications.  The "no_abbrevs" print mode
  1781 prevents folding of abbreviations in term output.
  1782 
  1783 Concrete syntax is attached to specified constants in internal form,
  1784 independently of name spaces.  The parse tree representation is
  1785 slightly different -- use 'notation' instead of raw 'syntax', and
  1786 'translations' with explicit "CONST" markup to accommodate this.
  1787 
  1788 * Pure/Isar: unified syntax for new-style specification mechanisms
  1789 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1790 full type inference and dummy patterns ("_").  For example:
  1791 
  1792   definition "K x _ = x"
  1793 
  1794   inductive conj for A B
  1795   where "A ==> B ==> conj A B"
  1796 
  1797 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1798 the current context.  Print mode "no_abbrevs" prevents inversion of
  1799 abbreviations on output.
  1800 
  1801 * Isar/locales: improved parameter handling: use of locales "var" and
  1802 "struct" no longer necessary; - parameter renamings are no longer
  1803 required to be injective.  For example, this allows to define
  1804 endomorphisms as locale endom = homom mult mult h.
  1805 
  1806 * Isar/locales: changed the way locales with predicates are defined.
  1807 Instead of accumulating the specification, the imported expression is
  1808 now an interpretation.  INCOMPATIBILITY: different normal form of
  1809 locale expressions.  In particular, in interpretations of locales with
  1810 predicates, goals repesenting already interpreted fragments are not
  1811 removed automatically.  Use methods `intro_locales' and
  1812 `unfold_locales'; see below.
  1813 
  1814 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1815 provide backward reasoning on locales predicates.  The methods are
  1816 aware of interpretations and discharge corresponding goals.
  1817 `intro_locales' is less aggressive then `unfold_locales' and does not
  1818 unfold predicates to assumptions.
  1819 
  1820 * Isar/locales: the order in which locale fragments are accumulated
  1821 has changed.  This enables to override declarations from fragments due
  1822 to interpretations -- for example, unwanted simp rules.
  1823 
  1824 * Isar/locales: interpretation in theories and proof contexts has been
  1825 extended.  One may now specify (and prove) equations, which are
  1826 unfolded in interpreted theorems.  This is useful for replacing
  1827 defined concepts (constants depending on locale parameters) by
  1828 concepts already existing in the target context.  Example:
  1829 
  1830   interpretation partial_order ["op <= :: [int, int] => bool"]
  1831     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1832 
  1833 Typically, the constant `partial_order.less' is created by a
  1834 definition specification element in the context of locale
  1835 partial_order.
  1836 
  1837 * Method "induct": improved internal context management to support
  1838 local fixes and defines on-the-fly. Thus explicit meta-level
  1839 connectives !!  and ==> are rarely required anymore in inductive goals
  1840 (using object-logic connectives for this purpose has been long
  1841 obsolete anyway). Common proof patterns are explained in
  1842 src/HOL/Induct/Common_Patterns.thy, see also
  1843 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1844 examples.
  1845 
  1846 * Method "induct": improved handling of simultaneous goals. Instead of
  1847 introducing object-level conjunction, the statement is now split into
  1848 several conclusions, while the corresponding symbolic cases are nested
  1849 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1850 see src/HOL/Induct/Common_Patterns.thy, for example.
  1851 
  1852 * Method "induct": mutual induction rules are now specified as a list
  1853 of rule sharing the same induction cases. HOL packages usually provide
  1854 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1855 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1856 mutual induction rules differently, i.e. like this:
  1857 
  1858   (induct rule: foo_bar.inducts)
  1859   (induct set: foo bar)
  1860   (induct pred: foo bar)
  1861   (induct type: foo bar)
  1862 
  1863 The ML function ProjectRule.projections turns old-style rules into the
  1864 new format.
  1865 
  1866 * Method "coinduct": dual of induction, see
  1867 src/HOL/Library/Coinductive_List.thy for various examples.
  1868 
  1869 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1870 considered a legacy feature.
  1871 
  1872 * Attribute "symmetric" produces result with standardized schematic
  1873 variables (index 0).  Potential INCOMPATIBILITY.
  1874 
  1875 * Simplifier: by default the simplifier trace only shows top level
  1876 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1877 default. Thus there is less danger of being flooded by the trace. The
  1878 trace indicates where parts have been suppressed.
  1879   
  1880 * Provers/classical: removed obsolete classical version of elim_format
  1881 attribute; classical elim/dest rules are now treated uniformly when
  1882 manipulating the claset.
  1883 
  1884 * Provers/classical: stricter checks to ensure that supplied intro,
  1885 dest and elim rules are well-formed; dest and elim rules must have at
  1886 least one premise.
  1887 
  1888 * Provers/classical: attributes dest/elim/intro take an optional
  1889 weight argument for the rule (just as the Pure versions).  Weights are
  1890 ignored by automated tools, but determine the search order of single
  1891 rule steps.
  1892 
  1893 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1894 where the body does not mention the bound variable.  Note that dummy
  1895 patterns implicitly depend on their context of bounds, which makes
  1896 "{_. _}" match any set comprehension as expected.  Potential
  1897 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1898 constant "_idtdummy" in the binding position.
  1899 
  1900 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1901 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1902 for example "A -> B" => "Pi A (%_. B)".
  1903 
  1904 * Pure: 'class_deps' command visualizes the subclass relation, using
  1905 the graph browser tool.
  1906 
  1907 * Pure: 'print_theory' now suppresses certain internal declarations by
  1908 default; use '!' option for full details.
  1909 
  1910 
  1911 *** HOL ***
  1912 
  1913 * Method "metis" proves goals by applying the Metis general-purpose
  1914 resolution prover (see also http://gilith.com/software/metis/).
  1915 Examples are in the directory MetisExamples.  WARNING: the
  1916 Isabelle/HOL-Metis integration does not yet work properly with
  1917 multi-threading.
  1918   
  1919 * Command 'sledgehammer' invokes external automatic theorem provers as
  1920 background processes.  It generates calls to the "metis" method if
  1921 successful. These can be pasted into the proof.  Users do not have to
  1922 wait for the automatic provers to return.  WARNING: does not really
  1923 work with multi-threading.
  1924 
  1925 * New "auto_quickcheck" feature tests outermost goal statements for
  1926 potential counter-examples.  Controlled by ML references
  1927 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1928 5000 milliseconds).  Fails silently if statements is outside of
  1929 executable fragment, or any other codgenerator problem occurs.
  1930 
  1931 * New constant "undefined" with axiom "undefined x = undefined".
  1932 
  1933 * Added class "HOL.eq", allowing for code generation with polymorphic
  1934 equality.
  1935 
  1936 * Some renaming of class constants due to canonical name prefixing in
  1937 the new 'class' package:
  1938 
  1939     HOL.abs ~> HOL.abs_class.abs
  1940     HOL.divide ~> HOL.divide_class.divide
  1941     0 ~> HOL.zero_class.zero
  1942     1 ~> HOL.one_class.one
  1943     op + ~> HOL.plus_class.plus
  1944     op - ~> HOL.minus_class.minus
  1945     uminus ~> HOL.minus_class.uminus
  1946     op * ~> HOL.times_class.times
  1947     op < ~> HOL.ord_class.less
  1948     op <= > HOL.ord_class.less_eq
  1949     Nat.power ~> Power.power_class.power
  1950     Nat.size ~> Nat.size_class.size
  1951     Numeral.number_of ~> Numeral.number_class.number_of
  1952     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1953     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1954     Orderings.min ~> Orderings.ord_class.min
  1955     Orderings.max ~> Orderings.ord_class.max
  1956     Divides.op div ~> Divides.div_class.div
  1957     Divides.op mod ~> Divides.div_class.mod
  1958     Divides.op dvd ~> Divides.div_class.dvd
  1959 
  1960 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1961 
  1962 a) User-defined constants using any of the names "plus", "minus",
  1963 "times", "less" or "less_eq". The standard syntax translations for
  1964 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1965 names.
  1966 
  1967 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1968 INCOMPATIBILITY: use more specific names.
  1969 
  1970 c) Permutative equations (e.g. "a + b = b + a")
  1971 Since the change of names also changes the order of terms, permutative
  1972 rewrite rules may get applied in a different order. Experience shows
  1973 that this is rarely the case (only two adaptions in the whole Isabelle
  1974 distribution).  INCOMPATIBILITY: rewrite proofs
  1975 
  1976 d) ML code directly refering to constant names
  1977 This in general only affects hand-written proof tactics, simprocs and
  1978 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1979 Consider using @{const_name} antiquotation.
  1980 
  1981 * New class "default" with associated constant "default".
  1982 
  1983 * Function "sgn" is now overloaded and available on int, real, complex
  1984 (and other numeric types), using class "sgn".  Two possible defs of
  1985 sgn are given as equational assumptions in the classes sgn_if and
  1986 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1987 INCOMPATIBILITY.
  1988 
  1989 * Locale "partial_order" now unified with class "order" (cf. theory
  1990 Orderings), added parameter "less".  INCOMPATIBILITY.
  1991 
  1992 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1993 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1994 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1995 
  1996 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1997 changed order of proof goals in instance proofs.
  1998 
  1999 * The transitivity reasoner for partial and linear orders is set up
  2000 for classes "order" and "linorder".  Instances of the reasoner are available
  2001 in all contexts importing or interpreting the corresponding locales.
  2002 Method "order" invokes the reasoner separately; the reasoner
  2003 is also integrated with the Simplifier as a solver.  Diagnostic
  2004 command 'print_orders' shows the available instances of the reasoner
  2005 in the current context.
  2006 
  2007 * Localized monotonicity predicate in theory "Orderings"; integrated
  2008 lemmas max_of_mono and min_of_mono with this predicate.
  2009 INCOMPATIBILITY.
  2010 
  2011 * Formulation of theorem "dense" changed slightly due to integration
  2012 with new class dense_linear_order.
  2013 
  2014 * Uniform lattice theory development in HOL.
  2015 
  2016     constants "meet" and "join" now named "inf" and "sup"
  2017     constant "Meet" now named "Inf"
  2018 
  2019     classes "meet_semilorder" and "join_semilorder" now named
  2020       "lower_semilattice" and "upper_semilattice"
  2021     class "lorder" now named "lattice"
  2022     class "comp_lat" now named "complete_lattice"
  2023 
  2024     Instantiation of lattice classes allows explicit definitions
  2025     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2026 
  2027   INCOMPATIBILITY.  Theorem renames:
  2028 
  2029     meet_left_le            ~> inf_le1
  2030     meet_right_le           ~> inf_le2
  2031     join_left_le            ~> sup_ge1
  2032     join_right_le           ~> sup_ge2
  2033     meet_join_le            ~> inf_sup_ord
  2034     le_meetI                ~> le_infI
  2035     join_leI                ~> le_supI
  2036     le_meet                 ~> le_inf_iff
  2037     le_join                 ~> ge_sup_conv
  2038     meet_idempotent         ~> inf_idem
  2039     join_idempotent         ~> sup_idem
  2040     meet_comm               ~> inf_commute
  2041     join_comm               ~> sup_commute
  2042     meet_leI1               ~> le_infI1
  2043     meet_leI2               ~> le_infI2
  2044     le_joinI1               ~> le_supI1
  2045     le_joinI2               ~> le_supI2
  2046     meet_assoc              ~> inf_assoc
  2047     join_assoc              ~> sup_assoc
  2048     meet_left_comm          ~> inf_left_commute
  2049     meet_left_idempotent    ~> inf_left_idem
  2050     join_left_comm          ~> sup_left_commute
  2051     join_left_idempotent    ~> sup_left_idem
  2052     meet_aci                ~> inf_aci
  2053     join_aci                ~> sup_aci
  2054     le_def_meet             ~> le_iff_inf
  2055     le_def_join             ~> le_iff_sup
  2056     join_absorp2            ~> sup_absorb2
  2057     join_absorp1            ~> sup_absorb1
  2058     meet_absorp1            ~> inf_absorb1
  2059     meet_absorp2            ~> inf_absorb2
  2060     meet_join_absorp        ~> inf_sup_absorb
  2061     join_meet_absorp        ~> sup_inf_absorb
  2062     distrib_join_le         ~> distrib_sup_le
  2063     distrib_meet_le         ~> distrib_inf_le
  2064 
  2065     add_meet_distrib_left   ~> add_inf_distrib_left
  2066     add_join_distrib_left   ~> add_sup_distrib_left
  2067     is_join_neg_meet        ~> is_join_neg_inf
  2068     is_meet_neg_join        ~> is_meet_neg_sup
  2069     add_meet_distrib_right  ~> add_inf_distrib_right
  2070     add_join_distrib_right  ~> add_sup_distrib_right
  2071     add_meet_join_distribs  ~> add_sup_inf_distribs
  2072     join_eq_neg_meet        ~> sup_eq_neg_inf
  2073     meet_eq_neg_join        ~> inf_eq_neg_sup
  2074     add_eq_meet_join        ~> add_eq_inf_sup
  2075     meet_0_imp_0            ~> inf_0_imp_0
  2076     join_0_imp_0            ~> sup_0_imp_0
  2077     meet_0_eq_0             ~> inf_0_eq_0
  2078     join_0_eq_0             ~> sup_0_eq_0
  2079     neg_meet_eq_join        ~> neg_inf_eq_sup
  2080     neg_join_eq_meet        ~> neg_sup_eq_inf
  2081     join_eq_if              ~> sup_eq_if
  2082 
  2083     mono_meet               ~> mono_inf
  2084     mono_join               ~> mono_sup
  2085     meet_bool_eq            ~> inf_bool_eq
  2086     join_bool_eq            ~> sup_bool_eq
  2087     meet_fun_eq             ~> inf_fun_eq
  2088     join_fun_eq             ~> sup_fun_eq
  2089     meet_set_eq             ~> inf_set_eq
  2090     join_set_eq             ~> sup_set_eq
  2091     meet1_iff               ~> inf1_iff
  2092     meet2_iff               ~> inf2_iff
  2093     meet1I                  ~> inf1I
  2094     meet2I                  ~> inf2I
  2095     meet1D1                 ~> inf1D1
  2096     meet2D1                 ~> inf2D1
  2097     meet1D2                 ~> inf1D2
  2098     meet2D2                 ~> inf2D2
  2099     meet1E                  ~> inf1E
  2100     meet2E                  ~> inf2E
  2101     join1_iff               ~> sup1_iff
  2102     join2_iff               ~> sup2_iff
  2103     join1I1                 ~> sup1I1
  2104     join2I1                 ~> sup2I1
  2105     join1I1                 ~> sup1I1
  2106     join2I2                 ~> sup1I2
  2107     join1CI                 ~> sup1CI
  2108     join2CI                 ~> sup2CI
  2109     join1E                  ~> sup1E
  2110     join2E                  ~> sup2E
  2111 
  2112     is_meet_Meet            ~> is_meet_Inf
  2113     Meet_bool_def           ~> Inf_bool_def
  2114     Meet_fun_def            ~> Inf_fun_def
  2115     Meet_greatest           ~> Inf_greatest
  2116     Meet_lower              ~> Inf_lower
  2117     Meet_set_def            ~> Inf_set_def
  2118 
  2119     Sup_def                 ~> Sup_Inf
  2120     Sup_bool_eq             ~> Sup_bool_def
  2121     Sup_fun_eq              ~> Sup_fun_def
  2122     Sup_set_eq              ~> Sup_set_def
  2123 
  2124     listsp_meetI            ~> listsp_infI
  2125     listsp_meet_eq          ~> listsp_inf_eq
  2126 
  2127     meet_min                ~> inf_min
  2128     join_max                ~> sup_max
  2129 
  2130 * Added syntactic class "size"; overloaded constant "size" now has
  2131 type "'a::size ==> bool"
  2132 
  2133 * Internal reorganisation of `size' of datatypes: size theorems
  2134 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2135 simplification rules by default!); theorems "prod.size" now named
  2136 "*.size".
  2137 
  2138 * Class "div" now inherits from class "times" rather than "type".
  2139 INCOMPATIBILITY.
  2140 
  2141 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2142 Linorder etc.  have disappeared; operations defined in terms of
  2143 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2144 
  2145 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2146 
  2147 * HOL-Word: New extensive library and type for generic, fixed size
  2148 machine words, with arithemtic, bit-wise, shifting and rotating
  2149 operations, reflection into int, nat, and bool lists, automation for
  2150 linear arithmetic (by automatic reflection into nat or int), including
  2151 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2152 arithmetic type classes, supporting automatic simplification of
  2153 numerals on all operations.
  2154 
  2155 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2156 
  2157 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2158 
  2159 * Code generator library theories:
  2160   - Code_Integer represents HOL integers by big integer literals in target
  2161     languages.
  2162   - Code_Char represents HOL characters by character literals in target
  2163     languages.
  2164   - Code_Char_chr like Code_Char, but also offers treatment of character
  2165     codes; includes Code_Integer.
  2166   - Executable_Set allows to generate code for finite sets using lists.
  2167   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2168     denominator).
  2169   - Executable_Real implements a subset of real numbers, namly those
  2170     representable by rational numbers.
  2171   - Efficient_Nat implements natural numbers by integers, which in general will
  2172     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2173     includes Code_Integer.
  2174   - Code_Index provides an additional datatype index which is mapped to
  2175     target-language built-in integers.
  2176   - Code_Message provides an additional datatype message_string which is isomorphic to
  2177     strings; messages are mapped to target-language strings.
  2178 
  2179 * New package for inductive predicates
  2180 
  2181   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2182 
  2183     inductive
  2184       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2185       for z_1 :: U_1 and ... and z_n :: U_m
  2186     where
  2187       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2188     | ...
  2189 
  2190   with full support for type-inference, rather than
  2191 
  2192     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2193 
  2194     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2195     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2196 
  2197     inductive "s z_1 ... z_m"
  2198     intros
  2199       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2200       ...
  2201 
  2202   For backward compatibility, there is a wrapper allowing inductive
  2203   sets to be defined with the new package via
  2204 
  2205     inductive_set
  2206       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2207       for z_1 :: U_1 and ... and z_n :: U_m
  2208     where
  2209       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2210     | ...
  2211 
  2212   or
  2213 
  2214     inductive_set
  2215       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2216       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2217       for z_1 :: U_1 and ... and z_n :: U_m
  2218     where
  2219       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2220     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2221     | ...
  2222 
  2223   if the additional syntax "p ..." is required.
  2224 
  2225   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2226   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2227 
  2228   INCOMPATIBILITIES:
  2229 
  2230   - Since declaration and definition of inductive sets or predicates
  2231     is no longer separated, abbreviations involving the newly
  2232     introduced sets or predicates must be specified together with the
  2233     introduction rules after the 'where' keyword (see above), rather
  2234     than before the actual inductive definition.
  2235 
  2236   - The variables in induction and elimination rules are now
  2237     quantified in the order of their occurrence in the introduction
  2238     rules, rather than in alphabetical order. Since this may break
  2239     some proofs, these proofs either have to be repaired, e.g. by
  2240     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2241     statements of the form
  2242 
  2243       case (rule_i a_i_1 ... a_i_{k_i})
  2244 
  2245     or the old order of quantification has to be restored by explicitly adding
  2246     meta-level quantifiers in the introduction rules, i.e.
  2247 
  2248       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2249 
  2250   - The format of the elimination rules is now
  2251 
  2252       p z_1 ... z_m x_1 ... x_n ==>
  2253         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2254         ==> ... ==> P
  2255 
  2256     for predicates and
  2257 
  2258       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2259         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2260         ==> ... ==> P
  2261 
  2262     for sets rather than
  2263 
  2264       x : s z_1 ... z_m ==>
  2265         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2266         ==> ... ==> P
  2267 
  2268     This may require terms in goals to be expanded to n-tuples
  2269     (e.g. using case_tac or simplification with the split_paired_all
  2270     rule) before the above elimination rule is applicable.
  2271 
  2272   - The elimination or case analysis rules for (mutually) inductive
  2273     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2274     list of rules "p_1_..._p_k.elims" is no longer available.
  2275 
  2276 * New package "function"/"fun" for general recursive functions,
  2277 supporting mutual and nested recursion, definitions in local contexts,
  2278 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2279 for small examples, and the separate tutorial on the function
  2280 package. The old recdef "package" is still available as before, but
  2281 users are encouraged to use the new package.
  2282 
  2283 * Method "lexicographic_order" automatically synthesizes termination
  2284 relations as lexicographic combinations of size measures. 
  2285 
  2286 * Case-expressions allow arbitrary constructor-patterns (including
  2287 "_") and take their order into account, like in functional
  2288 programming.  Internally, this is translated into nested
  2289 case-expressions; missing cases are added and mapped to the predefined
  2290 constant "undefined". In complicated cases printing may no longer show
  2291 the original input but the internal form. Lambda-abstractions allow
  2292 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2293 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2294 variable.
  2295 
  2296 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2297 is an abbreviation for "of_nat :: nat => int". The simplification
  2298 rules for "of_nat" have been changed to work like "int" did
  2299 previously.  Potential INCOMPATIBILITY:
  2300   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2301   - of_nat_diff and of_nat_mult are no longer default simp rules
  2302 
  2303 * Method "algebra" solves polynomial equations over (semi)rings using
  2304 Groebner bases. The (semi)ring structure is defined by locales and the
  2305 tool setup depends on that generic context. Installing the method for
  2306 a specific type involves instantiating the locale and possibly adding
  2307 declarations for computation on the coefficients.  The method is
  2308 already instantiated for natural numbers and for the axiomatic class
  2309 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2310 CALCULEMUS 2007 for the general principles underlying this
  2311 architecture of context-aware proof-tools.
  2312 
  2313 * Method "ferrack" implements quantifier elimination over
  2314 special-purpose dense linear orders using locales (analogous to
  2315 "algebra"). The method is already installed for class
  2316 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2317 rat, etc.
  2318 
  2319 * Former constant "List.op @" now named "List.append".  Use ML
  2320 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2321 circumvent possible incompatibilities when working on ML level.
  2322 
  2323 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2324 
  2325 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2326 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2327 
  2328 * New syntax for Haskell-like list comprehension (input only), eg.
  2329 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2330 
  2331 * The special syntax for function "filter" has changed from [x :
  2332 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2333 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2334 
  2335 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2336 defined on nat only, as an abbreviation for [a..<Suc b]
  2337 INCOMPATIBILITY.
  2338 
  2339 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2340 
  2341 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2342 
  2343 * New lemma collection field_simps (an extension of ring_simps) for
  2344 manipulating (in)equations involving division. Multiplies with all
  2345 denominators that can be proved to be non-zero (in equations) or
  2346 positive/negative (in inequations).
  2347 
  2348 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2349 have been improved and renamed to ring_simps, group_simps and
  2350 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2351 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2352 
  2353 * Theory Library/Commutative_Ring: switched from recdef to function
  2354 package; constants add, mul, pow now curried.  Infix syntax for
  2355 algebraic operations.
  2356 
  2357 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2358 INCOMPATIBILITY.
  2359 
  2360 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2361 INCOMPATIBILITY.
  2362 
  2363 * HOL/records: generalised field-update to take a function on the
  2364 field rather than the new value: r(|A := x|) is translated to A_update
  2365 (K x) r The K-combinator that is internally used is called K_record.
  2366 INCOMPATIBILITY: Usage of the plain update functions has to be
  2367 adapted.
  2368  
  2369 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2370 * x = 0, which are required for a semiring.  Richer structures do not
  2371 inherit from semiring_0 anymore, because this property is a theorem
  2372 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2373 there is more to prove, but this is mostly trivial.
  2374 
  2375 * Class "recpower" is generalized to arbitrary monoids, not just
  2376 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2377 commutativity or semiring properties additionally.
  2378 
  2379 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2380 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2381 better use 'abbreviation'.
  2382 
  2383 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2384 
  2385 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2386 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2387 significant changes for setting up numeral syntax for types:
  2388   - New constants Numeral.pred and Numeral.succ instead
  2389       of former Numeral.bin_pred and Numeral.bin_succ.
  2390   - Use integer operations instead of bin_add, bin_mult and so on.
  2391   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2392   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2393 
  2394 See src/HOL/Integ/IntArith.thy for an example setup.
  2395 
  2396 * Command 'normal_form' computes the normal form of a term that may
  2397 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2398 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2399 heavy-duty computations because the functions are compiled to ML
  2400 first.  Correspondingly, a method "normalization" is provided.  See
  2401 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2402 
  2403 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2404 25 like -->); output depends on the "iff" print_mode, the default is
  2405 "A = B" (with priority 50).
  2406 
  2407 * Relations less (<) and less_eq (<=) are also available on type bool.
  2408 Modified syntax to disallow nesting without explicit parentheses,
  2409 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2410 INCOMPATIBILITY.
  2411 
  2412 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2413 
  2414 * Relation composition operator "op O" now has precedence 75 and binds
  2415 stronger than union and intersection. INCOMPATIBILITY.
  2416 
  2417 * The old set interval syntax "{m..n(}" (and relatives) has been
  2418 removed.  Use "{m..<n}" (and relatives) instead.
  2419 
  2420 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2421 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2422 ``declare [[simproc del: neq]]''.
  2423 
  2424 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2425 True/False.
  2426 
  2427 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2428 
  2429 * Theorem setsum_mult renamed to setsum_right_distrib.
  2430 
  2431 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2432 ``rule'' method.
  2433 
  2434 * Reimplemented methods "sat" and "satx", with several improvements:
  2435 goals no longer need to be stated as "<prems> ==> False", equivalences
  2436 (i.e. "=" on type bool) are handled, variable names of the form
  2437 "lit_<n>" are no longer reserved, significant speedup.
  2438 
  2439 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2440 zChaff is still supported as well.
  2441 
  2442 * 'inductive' and 'datatype': provide projections of mutual rules,
  2443 bundled as foo_bar.inducts;
  2444 
  2445 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2446 Library.
  2447 
  2448 * Library: moved theory Accessible_Part to main HOL.
  2449 
  2450 * Library: added theory Coinductive_List of potentially infinite lists
  2451 as greatest fixed-point.
  2452 
  2453 * Library: added theory AssocList which implements (finite) maps as
  2454 association lists.
  2455 
  2456 * Method "evaluation" solves goals (i.e. a boolean expression)
  2457 efficiently by compiling it to ML.  The goal is "proved" (via an
  2458 oracle) if it evaluates to True.
  2459 
  2460 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2461 also when invoked by the simplifier.  This results in the Simplifier
  2462 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2463 Configuration option fast_arith_split_limit=0 recovers the old
  2464 behavior.
  2465 
  2466 * Support for hex (0x20) and binary (0b1001) numerals.
  2467 
  2468 * New method: reify eqs (t), where eqs are equations for an
  2469 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2470 parameter, computes a term s::'b and a list xs::'a list and proves the
  2471 theorem I xs s = t. This is also known as reification or quoting. The
  2472 resulting theorem is applied to the subgoal to substitute t with I xs
  2473 s.  If t is omitted, the subgoal itself is reified.
  2474 
  2475 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2476 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2477 where f is supposed to be a computable function (in the sense of code
  2478 generattion). The method uses reify to compute s and xs as above then
  2479 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2480 r and finally gets the theorem t = r, which is again applied to the
  2481 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2482 
  2483 * Reflection: Automatic reification now handels binding, an example is
  2484 available in src/HOL/ex/ReflectionEx.thy
  2485 
  2486 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2487 command 'statespace' that is similar to 'record', but introduces an
  2488 abstract specification based on the locale infrastructure instead of
  2489 HOL types.  This leads to extra flexibility in composing state spaces,
  2490 in particular multiple inheritance and renaming of components.
  2491 
  2492 
  2493 *** HOL-Complex ***
  2494 
  2495 * Hyperreal: Functions root and sqrt are now defined on negative real
  2496 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2497 Nonnegativity side conditions have been removed from many lemmas, so
  2498 that more subgoals may now be solved by simplification; potential
  2499 INCOMPATIBILITY.
  2500 
  2501 * Real: new type classes formalize real normed vector spaces and
  2502 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2503 and norm :: 'a => real.
  2504 
  2505 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2506 reals into other types. The overloaded constant Reals :: 'a set is now
  2507 defined as range of_real; potential INCOMPATIBILITY.
  2508 
  2509 * Real: proper support for ML code generation, including 'quickcheck'.
  2510 Reals are implemented as arbitrary precision rationals.
  2511 
  2512 * Hyperreal: Several constants that previously worked only for the
  2513 reals have been generalized, so they now work over arbitrary vector
  2514 spaces. Type annotations may need to be added in some cases; potential
  2515 INCOMPATIBILITY.
  2516 
  2517   Infinitesimal  :: ('a::real_normed_vector) star set
  2518   HFinite        :: ('a::real_normed_vector) star set
  2519   HInfinite      :: ('a::real_normed_vector) star set
  2520   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2521   monad          :: ('a::real_normed_vector) star => 'a star set
  2522   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2523   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2524   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2525   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2526   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2527   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2528   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2529   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2530   sgn            :: 'a::real_normed_vector => 'a
  2531   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2532 
  2533 * Complex: Some complex-specific constants are now abbreviations for
  2534 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2535 hnorm.  Other constants have been entirely removed in favor of the
  2536 polymorphic versions (INCOMPATIBILITY):
  2537 
  2538   approx        <-- capprox
  2539   HFinite       <-- CFinite
  2540   HInfinite     <-- CInfinite
  2541   Infinitesimal <-- CInfinitesimal
  2542   monad         <-- cmonad
  2543   galaxy        <-- cgalaxy
  2544   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2545   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2546   (ns)deriv     <-- (ns)cderiv
  2547 
  2548 
  2549 *** HOL-Algebra ***
  2550 
  2551 * Formalisation of ideals and the quotient construction over rings.
  2552 
  2553 * Order and lattice theory no longer based on records.
  2554 INCOMPATIBILITY.
  2555 
  2556 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2557 greatest_closed.  INCOMPATIBILITY.
  2558 
  2559 * Method algebra is now set up via an attribute.  For examples see
  2560 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2561 of algebraic structures.
  2562 
  2563 * Renamed theory CRing to Ring.
  2564 
  2565 
  2566 *** HOL-Nominal ***
  2567 
  2568 * Substantial, yet incomplete support for nominal datatypes (binding
  2569 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2570 src/HOL/Nominal/Examples.  Prospective users should consult
  2571 http://isabelle.in.tum.de/nominal/
  2572 
  2573 
  2574 *** ML ***
  2575 
  2576 * ML basics: just one true type int, which coincides with IntInf.int
  2577 (even on SML/NJ).
  2578 
  2579 * ML within Isar: antiquotations allow to embed statically-checked
  2580 formal entities in the source, referring to the context available at
  2581 compile-time.  For example:
  2582 
  2583 ML {* @{sort "{zero,one}"} *}
  2584 ML {* @{typ "'a => 'b"} *}
  2585 ML {* @{term "%x. x"} *}
  2586 ML {* @{prop "x == y"} *}
  2587 ML {* @{ctyp "'a => 'b"} *}
  2588 ML {* @{cterm "%x. x"} *}
  2589 ML {* @{cprop "x == y"} *}
  2590 ML {* @{thm asm_rl} *}
  2591 ML {* @{thms asm_rl} *}
  2592 ML {* @{type_name c} *}
  2593 ML {* @{type_syntax c} *}
  2594 ML {* @{const_name c} *}
  2595 ML {* @{const_syntax c} *}
  2596 ML {* @{context} *}
  2597 ML {* @{theory} *}
  2598 ML {* @{theory Pure} *}
  2599 ML {* @{theory_ref} *}
  2600 ML {* @{theory_ref Pure} *}
  2601 ML {* @{simpset} *}
  2602 ML {* @{claset} *}
  2603 ML {* @{clasimpset} *}
  2604 
  2605 The same works for sources being ``used'' within an Isar context.
  2606 
  2607 * ML in Isar: improved error reporting; extra verbosity with
  2608 ML_Context.trace enabled.
  2609 
  2610 * Pure/General/table.ML: the join operations now works via exceptions
  2611 DUP/SAME instead of type option. This is simpler in simple cases, and
  2612 admits slightly more efficient complex applications.
  2613 
  2614 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2615 use Context.generic instead of just theory.
  2616 
  2617 * Pure: datatype Context.generic joins theory/Proof.context and
  2618 provides some facilities for code that works in either kind of
  2619 context, notably GenericDataFun for uniform theory and proof data.
  2620 
  2621 * Pure: simplified internal attribute type, which is now always
  2622 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2623 local (Proof.context) attributes have been discontinued, while
  2624 minimizing code duplication. Thm.rule_attribute and
  2625 Thm.declaration_attribute build canonical attributes; see also structure
  2626 Context for further operations on Context.generic, notably
  2627 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2628 declarations and definitions.
  2629 
  2630 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2631 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2632 init only required for impure data. INCOMPATIBILITY: empty really need
  2633 to be empty (no dependencies on theory content!)
  2634 
  2635 * Pure/kernel: consts certification ignores sort constraints given in
  2636 signature declarations. (This information is not relevant to the
  2637 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2638 potential INCOMPATIBILITY.
  2639 
  2640 * Pure: axiomatic type classes are now purely definitional, with
  2641 explicit proofs of class axioms and super class relations performed
  2642 internally. See Pure/axclass.ML for the main internal interfaces --
  2643 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2644 AxClass.axiomatize_class/classrel/arity supersede
  2645 Sign.add_classes/classrel/arities.
  2646 
  2647 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2648 global/local versions on theory vs. Proof.context have been
  2649 discontinued; Attrib.syntax and Method.syntax have been adapted
  2650 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2651 attributes, methods, etc.
  2652 
  2653 * Pure: several functions of signature "... -> theory -> theory * ..."
  2654 have been reoriented to "... -> theory -> ... * theory" in order to
  2655 allow natural usage in combination with the ||>, ||>>, |-> and
  2656 fold_map combinators.
  2657 
  2658 * Pure: official theorem names (closed derivations) and additional
  2659 comments (tags) are now strictly separate.  Name hints -- which are
  2660 maintained as tags -- may be attached any time without affecting the
  2661 derivation.
  2662 
  2663 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2664 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2665 achieve the old behaviour.
  2666 
  2667 * Pure: the "Goal" constant is now called "prop", supporting a
  2668 slightly more general idea of ``protecting'' meta-level rule
  2669 statements.
  2670 
  2671 * Pure: Logic.(un)varify only works in a global context, which is now
  2672 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2673 Logic.legacy_(un)varify as temporary workaround.
  2674 
  2675 * Pure: structure Name provides scalable operations for generating
  2676 internal variable names, notably Name.variants etc.  This replaces
  2677 some popular functions from term.ML:
  2678 
  2679   Term.variant		->  Name.variant
  2680   Term.variantlist	->  Name.variant_list
  2681   Term.invent_names	->  Name.invent_list
  2682 
  2683 Note that low-level renaming rarely occurs in new code -- operations
  2684 from structure Variable are used instead (see below).
  2685 
  2686 * Pure: structure Variable provides fundamental operations for proper
  2687 treatment of fixed/schematic variables in a context.  For example,
  2688 Variable.import introduces fixes for schematics of given facts and
  2689 Variable.export reverses the effect (up to renaming) -- this replaces
  2690 various freeze_thaw operations.
  2691 
  2692 * Pure: structure Goal provides simple interfaces for
  2693 init/conclude/finish and tactical prove operations (replacing former
  2694 Tactic.prove).  Goal.prove is the canonical way to prove results
  2695 within a given context; Goal.prove_global is a degraded version for
  2696 theory level goals, including a global Drule.standard.  Note that
  2697 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2698 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2699 in a locale context).
  2700 
  2701 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2702 and type checking (Syntax.check_term etc.), with common combinations
  2703 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2704 which are considered legacy and await removal.
  2705 
  2706 * Pure/Syntax: generic interfaces for type unchecking
  2707 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2708 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2709 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2710 available for convenience, but refer to the very same operations using
  2711 a mere theory instead of a full context.
  2712 
  2713 * Isar: simplified treatment of user-level errors, using exception
  2714 ERROR of string uniformly.  Function error now merely raises ERROR,
  2715 without any side effect on output channels.  The Isar toplevel takes
  2716 care of proper display of ERROR exceptions.  ML code may use plain
  2717 handle/can/try; cat_error may be used to concatenate errors like this:
  2718 
  2719   ... handle ERROR msg => cat_error msg "..."
  2720 
  2721 Toplevel ML code (run directly or through the Isar toplevel) may be
  2722 embedded into the Isar toplevel with exception display/debug like
  2723 this:
  2724 
  2725   Isar.toplevel (fn () => ...)
  2726 
  2727 INCOMPATIBILITY, removed special transform_error facilities, removed
  2728 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2729 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2730 -- use plain ERROR instead.
  2731 
  2732 * Isar: theory setup now has type (theory -> theory), instead of a
  2733 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2734 
  2735 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2736 ProofContext.debug/verbose flags.
  2737 
  2738 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2739 theory before entering a proof state.  Transactions now always see a
  2740 quasi-functional intermediate checkpoint, both in interactive and
  2741 batch mode.
  2742 
  2743 * Isar: simplified interfaces for outer syntax.  Renamed
  2744 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2745 OuterSyntax.add_parsers -- this functionality is now included in
  2746 OuterSyntax.command etc.  INCOMPATIBILITY.
  2747 
  2748 * Simplifier: the simpset of a running simplification process now
  2749 contains a proof context (cf. Simplifier.the_context), which is the
  2750 very context that the initial simpset has been retrieved from (by
  2751 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2752 (solver, looper etc.) may depend on arbitrary proof data.
  2753 
  2754 * Simplifier.inherit_context inherits the proof context (plus the
  2755 local bounds) of the current simplification process; any simproc
  2756 etc. that calls the Simplifier recursively should do this!  Removed
  2757 former Simplifier.inherit_bounds, which is already included here --
  2758 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2759 specify an explicit context using Simplifier.context/theory_context.
  2760 
  2761 * Simplifier/Classical Reasoner: more abstract interfaces
  2762 change_simpset/claset for modifying the simpset/claset reference of a
  2763 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2764 INCOMPATIBILITY.
  2765 
  2766 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2767 "Trueprop" etc.
  2768 
  2769 
  2770 *** System ***
  2771 
  2772 * settings: the default heap location within ISABELLE_HOME_USER now
  2773 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2774 Isabelle installations.
  2775 
  2776 * isabelle-process: option -S (secure mode) disables some critical
  2777 operations, notably runtime compilation and evaluation of ML source
  2778 code.
  2779 
  2780 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2781 
  2782 * Support for parallel execution, using native multicore support of
  2783 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2784 independent theories, according to the given theory header
  2785 specifications. The maximum number of worker threads is specified via
  2786 usedir option -M or the "max-threads" setting in Proof General. A
  2787 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2788 to 6 on a 8-core machine.  User-code needs to observe certain
  2789 guidelines for thread-safe programming, see appendix A in the Isar
  2790 Implementation manual.
  2791 
  2792 
  2793 
  2794 New in Isabelle2005 (October 2005)
  2795 ----------------------------------
  2796 
  2797 *** General ***
  2798 
  2799 * Theory headers: the new header syntax for Isar theories is
  2800 
  2801   theory <name>
  2802   imports <theory1> ... <theoryN>
  2803   uses <file1> ... <fileM>
  2804   begin
  2805 
  2806 where the 'uses' part is optional.  The previous syntax
  2807 
  2808   theory <name> = <theory1> + ... + <theoryN>:
  2809 
  2810 will disappear in the next release.  Use isatool fixheaders to convert
  2811 existing theory files.  Note that there is no change in ancient
  2812 non-Isar theories now, but these will disappear soon.
  2813 
  2814 * Theory loader: parent theories can now also be referred to via
  2815 relative and absolute paths.
  2816 
  2817 * Command 'find_theorems' searches for a list of criteria instead of a
  2818 list of constants. Known criteria are: intro, elim, dest, name:string,
  2819 simp:term, and any term. Criteria can be preceded by '-' to select
  2820 theorems that do not match. Intro, elim, dest select theorems that
  2821 match the current goal, name:s selects theorems whose fully qualified
  2822 name contain s, and simp:term selects all simplification rules whose
  2823 lhs match term.  Any other term is interpreted as pattern and selects
  2824 all theorems matching the pattern. Available in ProofGeneral under
  2825 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2826 
  2827   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2828 
  2829 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2830 matching the current goal as introduction rule and not having "HOL."
  2831 in their name (i.e. not being defined in theory HOL).
  2832 
  2833 * Command 'thms_containing' has been discontinued in favour of
  2834 'find_theorems'; INCOMPATIBILITY.
  2835 
  2836 * Communication with Proof General is now 8bit clean, which means that
  2837 Unicode text in UTF-8 encoding may be used within theory texts (both
  2838 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2839 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2840 
  2841   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2842   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2843 
  2844 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2845 Classical Reasoner.  Typical big applications run around 2 times
  2846 faster.
  2847 
  2848 
  2849 *** Document preparation ***
  2850 
  2851 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2852 of raw sources.  Only those symbols that do not require additional
  2853 LaTeX packages (depending on comments in isabellesym.sty) are
  2854 displayed properly, everything else is left verbatim.  isatool display
  2855 and isatool print are used as front ends (these are subject to the
  2856 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2857 
  2858 * Command tags control specific markup of certain regions of text,
  2859 notably folding and hiding.  Predefined tags include "theory" (for
  2860 theory begin and end), "proof" for proof commands, and "ML" for
  2861 commands involving ML code; the additional tags "visible" and
  2862 "invisible" are unused by default.  Users may give explicit tag
  2863 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2864 interpretation of tags is determined by the LaTeX job during document
  2865 preparation: see option -V of isatool usedir, or options -n and -t of
  2866 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2867 \isadroptag.
  2868 
  2869 Several document versions may be produced at the same time via isatool
  2870 usedir (the generated index.html will link all of them).  Typical
  2871 specifications include ''-V document=theory,proof,ML'' to present
  2872 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2873 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2874 these parts without any formal replacement text.  The Isabelle site
  2875 default settings produce ''document'' and ''outline'' versions as
  2876 specified above.
  2877 
  2878 * Several new antiquotations:
  2879 
  2880   @{term_type term} prints a term with its type annotated;
  2881 
  2882   @{typeof term} prints the type of a term;
  2883 
  2884   @{const const} is the same as @{term const}, but checks that the
  2885   argument is a known logical constant;
  2886 
  2887   @{term_style style term} and @{thm_style style thm} print a term or
  2888   theorem applying a "style" to it
  2889 
  2890   @{ML text}
  2891 
  2892 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2893 definitions, equations, inequations etc., 'concl' printing only the
  2894 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2895 to print the specified premise.  TermStyle.add_style provides an ML
  2896 interface for introducing further styles.  See also the "LaTeX Sugar"
  2897 document practical applications.  The ML antiquotation prints
  2898 type-checked ML expressions verbatim.
  2899 
  2900 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2901 and 'text' support optional locale specification '(in loc)', which
  2902 specifies the default context for interpreting antiquotations.  For
  2903 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2904 
  2905 * Option 'locale=NAME' of antiquotations specifies an alternative
  2906 context interpreting the subsequent argument.  For example: @{thm
  2907 [locale=lattice] inf_assoc}.
  2908 
  2909 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2910 a proof context.
  2911 
  2912 * Proper output of antiquotations for theory commands involving a
  2913 proof context (such as 'locale' or 'theorem (in loc) ...').
  2914 
  2915 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2916 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2917 
  2918 * isatool usedir: new option -C (default true) controls whether option
  2919 -D should include a copy of the original document directory; -C false
  2920 prevents unwanted effects such as copying of administrative CVS data.
  2921 
  2922 
  2923 *** Pure ***
  2924 
  2925 * Considerably improved version of 'constdefs' command.  Now performs
  2926 automatic type-inference of declared constants; additional support for
  2927 local structure declarations (cf. locales and HOL records), see also
  2928 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2929 sequential dependencies of definitions within a single 'constdefs'
  2930 section; moreover, the declared name needs to be an identifier.  If
  2931 all fails, consider to fall back on 'consts' and 'defs' separately.
  2932 
  2933 * Improved indexed syntax and implicit structures.  First of all,
  2934 indexed syntax provides a notational device for subscripted
  2935 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2936 expressions.  Secondly, in a local context with structure
  2937 declarations, number indexes \<^sub>n or the empty index (default
  2938 number 1) refer to a certain fixed variable implicitly; option
  2939 show_structs controls printing of implicit structures.  Typical
  2940 applications of these concepts involve record types and locales.
  2941 
  2942 * New command 'no_syntax' removes grammar declarations (and
  2943 translations) resulting from the given syntax specification, which is
  2944 interpreted in the same manner as for the 'syntax' command.
  2945 
  2946 * 'Advanced' translation functions (parse_translation etc.) may depend
  2947 on the signature of the theory context being presently used for
  2948 parsing/printing, see also isar-ref manual.
  2949 
  2950 * Improved 'oracle' command provides a type-safe interface to turn an
  2951 ML expression of type theory -> T -> term into a primitive rule of
  2952 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2953 is already included here); see also FOL/ex/IffExample.thy;
  2954 INCOMPATIBILITY.
  2955 
  2956 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2957 before); "cI" is no longer bound, use "c.intro" instead.
  2958 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2959 axclasses vs. locales.
  2960 
  2961 * Improved internal renaming of symbolic identifiers -- attach primes
  2962 instead of base 26 numbers.
  2963 
  2964 * New flag show_question_marks controls printing of leading question
  2965 marks in schematic variable names.
  2966 
  2967 * In schematic variable names, *any* symbol following \<^isub> or
  2968 \<^isup> is now treated as part of the base name.  For example, the
  2969 following works without printing of awkward ".0" indexes:
  2970 
  2971   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2972     by simp
  2973 
  2974 * Inner syntax includes (*(*nested*) comments*).
  2975 
  2976 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2977 annotations as "(00...)".
  2978 
  2979 * Clear separation of logical types and nonterminals, where the latter
  2980 may only occur in 'syntax' specifications or type abbreviations.
  2981 Before that distinction was only partially implemented via type class
  2982 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2983 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2984 exotic syntax specifications may require further adaption
  2985 (e.g. Cube/Cube.thy).
  2986 
  2987 * Removed obsolete type class "logic", use the top sort {} instead.
  2988 Note that non-logical types should be declared as 'nonterminals'
  2989 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2990 specifications.
  2991 
  2992 * Attributes 'induct' and 'cases': type or set names may now be
  2993 locally fixed variables as well.
  2994 
  2995 * Simplifier: can now control the depth to which conditional rewriting
  2996 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2997 Limit.
  2998 
  2999 * Simplifier: simplification procedures may now take the current
  3000 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3001 interface), which is very useful for calling the Simplifier
  3002 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3003 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3004 low-level mk_simproc no longer applies Logic.varify internally, to
  3005 allow for use in a context of fixed variables.
  3006 
  3007 * thin_tac now works even if the assumption being deleted contains !!
  3008 or ==>.  More generally, erule now works even if the major premise of
  3009 the elimination rule contains !! or ==>.
  3010 
  3011 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3012 
  3013 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3014 from Pure, which contains all common declarations already.  Both
  3015 theories are defined via plain Isabelle/Isar .thy files.
  3016 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3017 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3018 use isatool fixcpure to adapt your theory and ML sources.
  3019 
  3020 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3021 selections of theorems in named facts via index ranges.
  3022 
  3023 * 'print_theorems': in theory mode, really print the difference
  3024 wrt. the last state (works for interactive theory development only),
  3025 in proof mode print all local facts (cf. 'print_facts');
  3026 
  3027 * 'hide': option '(open)' hides only base names.
  3028 
  3029 * More efficient treatment of intermediate checkpoints in interactive
  3030 theory development.
  3031 
  3032 * Code generator is now invoked via code_module (incremental code
  3033 generation) and code_library (modular code generation, ML structures
  3034 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3035 must be quoted when used as identifiers.
  3036 
  3037 * New 'value' command for reading, evaluating and printing terms using
  3038 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3039 quoted when used as identifier.
  3040 
  3041 
  3042 *** Locales ***
  3043 
  3044 * New commands for the interpretation of locale expressions in
  3045 theories (1), locales (2) and proof contexts (3).  These generate
  3046 proof obligations from the expression specification.  After the
  3047 obligations have been discharged, theorems of the expression are added
  3048 to the theory, target locale or proof context.  The synopsis of the
  3049 commands is a follows:
  3050 
  3051   (1) interpretation expr inst
  3052   (2) interpretation target < expr
  3053   (3) interpret expr inst
  3054 
  3055 Interpretation in theories and proof contexts require a parameter
  3056 instantiation of terms from the current context.  This is applied to
  3057 specifications and theorems of the interpreted expression.
  3058 Interpretation in locales only permits parameter renaming through the
  3059 locale expression.  Interpretation is smart in that interpretations
  3060 that are active already do not occur in proof obligations, neither are
  3061 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3062 inspect active interpretations of a particular locale.  For details,
  3063 see the Isar Reference manual.  Examples can be found in
  3064 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3065 
  3066 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3067 'interpret' instead.
  3068 
  3069 * New context element 'constrains' for adding type constraints to
  3070 parameters.
  3071 
  3072 * Context expressions: renaming of parameters with syntax
  3073 redeclaration.
  3074 
  3075 * Locale declaration: 'includes' disallowed.
  3076 
  3077 * Proper static binding of attribute syntax -- i.e. types / terms /
  3078 facts mentioned as arguments are always those of the locale definition
  3079 context, independently of the context of later invocations.  Moreover,
  3080 locale operations (renaming and type / term instantiation) are applied
  3081 to attribute arguments as expected.
  3082 
  3083 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3084 actual attributes; rare situations may require Attrib.attribute to
  3085 embed those attributes into Attrib.src that lack concrete syntax.
  3086 Attribute implementations need to cooperate properly with the static
  3087 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3088 Attrib.XXX_thm etc. already do the right thing without further
  3089 intervention.  Only unusual applications -- such as "where" or "of"
  3090 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3091 on the context and the facts involved -- may have to assign parsed
  3092 values to argument tokens explicitly.
  3093 
  3094 * Changed parameter management in theorem generation for long goal
  3095 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3096 theorem statement in rare situations.
  3097 
  3098 * Locale inspection command 'print_locale' omits notes elements.  Use
  3099 'print_locale!' to have them included in the output.
  3100 
  3101 
  3102 *** Provers ***
  3103 
  3104 * Provers/hypsubst.ML: improved version of the subst method, for
  3105 single-step rewriting: it now works in bound variable contexts. New is
  3106 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3107 rewrite a different subterm than the original subst method, which is
  3108 still available as 'simplesubst'.
  3109 
  3110 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3111 and quasi orders.
  3112 
  3113 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3114 reflexive-transitive closure of relations.
  3115 
  3116 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3117 limit (previously hard-coded with a value of 20) user-definable.
  3118 
  3119 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3120 is peformed already.  Object-logics merely need to finish their
  3121 initial simpset configuration as before.  INCOMPATIBILITY.
  3122 
  3123 
  3124 *** HOL ***
  3125 
  3126 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3127 
  3128   syntax (epsilon)
  3129     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3130 
  3131 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3132 and x-symbol; use option '-m epsilon' to get it actually printed.
  3133 Moreover, the mathematically important symbolic identifier \<epsilon>
  3134 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3135 
  3136 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3137 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3138 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3139 support corresponding Isar calculations.
  3140 
  3141 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3142 instead of ":".
  3143 
  3144 * theory SetInterval: changed the syntax for open intervals:
  3145 
  3146   Old       New
  3147   {..n(}    {..<n}
  3148   {)n..}    {n<..}
  3149   {m..n(}   {m..<n}
  3150   {)m..n}   {m<..n}
  3151   {)m..n(}  {m<..<n}
  3152 
  3153 The old syntax is still supported but will disappear in the next
  3154 release.  For conversion use the following Emacs search and replace
  3155 patterns (these are not perfect but work quite well):
  3156 
  3157   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3158   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3159 
  3160 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3161 equalities in commutative rings; method 'algebra' provides a generic
  3162 interface.
  3163 
  3164 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3165 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3166 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3167 be a tuple pattern.
  3168 
  3169 Some new syntax forms are available:
  3170 
  3171   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3172   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3173   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3174   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3175 
  3176 The latter form "\<Sum>x < k. e" used to be based on a separate
  3177 function "Summation", which has been discontinued.
  3178 
  3179 * theory Finite_Set: in structured induction proofs, the insert case
  3180 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3181 (insert F x)'.
  3182 
  3183 * The 'refute' command has been extended to support a much larger
  3184 fragment of HOL, including axiomatic type classes, constdefs and
  3185 typedefs, inductive datatypes and recursion.
  3186 
  3187 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3188 Requires zChaff with proof generation to be installed.  See
  3189 HOL/ex/SAT_Examples.thy for examples.
  3190 
  3191 * Datatype induction via method 'induct' now preserves the name of the
  3192 induction variable. For example, when proving P(xs::'a list) by
  3193 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3194 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3195 in unstructured proof scripts.
  3196 
  3197 * Reworked implementation of records.  Improved scalability for
  3198 records with many fields, avoiding performance problems for type
  3199 inference. Records are no longer composed of nested field types, but
  3200 of nested extension types. Therefore the record type only grows linear
  3201 in the number of extensions and not in the number of fields.  The
  3202 top-level (users) view on records is preserved.  Potential
  3203 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3204 old record representation. The type generated for a record is called
  3205 <record_name>_ext_type.
  3206 
  3207 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3208 proofs triggered by a record definition or a simproc (if
  3209 quick_and_dirty is enabled).  Definitions of large records can take
  3210 quite long.
  3211 
  3212 New simproc record_upd_simproc for simplification of multiple record
  3213 updates enabled by default.  Moreover, trivial updates are also
  3214 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3215 occasionally, since simplification is more powerful by default.
  3216 
  3217 * typedef: proper support for polymorphic sets, which contain extra
  3218 type-variables in the term.
  3219 
  3220 * Simplifier: automatically reasons about transitivity chains
  3221 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3222 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3223 old proofs break occasionally as simplification may now solve more
  3224 goals than previously.
  3225 
  3226 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3227 present.  Works for all partial orders (class "order"), in particular
  3228 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3229 just like y <= x.
  3230 
  3231 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3232 bound variable or a constant then the let is unfolded.  Otherwise
  3233 first a is simplified to b, and then f b is simplified to g. If
  3234 possible we abstract b from g arriving at "let x = b in h x",
  3235 otherwise we unfold the let and arrive at g.  The simproc can be
  3236 enabled/disabled by the reference use_let_simproc.  Potential
  3237 INCOMPATIBILITY since simplification is more powerful by default.
  3238 
  3239 * Classical reasoning: the meson method now accepts theorems as arguments.
  3240 
  3241 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3242 jobs to provide advice on the provability of subgoals.
  3243 
  3244 * Theory OrderedGroup and Ring_and_Field: various additions and
  3245 improvements to faciliate calculations involving equalities and
  3246 inequalities.
  3247 
  3248 The following theorems have been eliminated or modified
  3249 (INCOMPATIBILITY):
  3250 
  3251   abs_eq             now named abs_of_nonneg
  3252   abs_of_ge_0        now named abs_of_nonneg
  3253   abs_minus_eq       now named abs_of_nonpos
  3254   imp_abs_id         now named abs_of_nonneg
  3255   imp_abs_neg_id     now named abs_of_nonpos
  3256   mult_pos           now named mult_pos_pos
  3257   mult_pos_le        now named mult_nonneg_nonneg
  3258   mult_pos_neg_le    now named mult_nonneg_nonpos
  3259   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3260   mult_neg           now named mult_neg_neg
  3261   mult_neg_le        now named mult_nonpos_nonpos
  3262 
  3263 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3264      
  3265      zero_le_square
  3266      not_square_less_zero 
  3267 
  3268   The following lemmas have been deleted from Real/RealPow:
  3269   
  3270      realpow_zero_zero
  3271      realpow_two
  3272      realpow_less
  3273      zero_le_power
  3274      realpow_two_le
  3275      abs_realpow_two
  3276      realpow_two_abs     
  3277 
  3278 * Theory Parity: added rules for simplifying exponents.
  3279 
  3280 * Theory List:
  3281 
  3282 The following theorems have been eliminated or modified
  3283 (INCOMPATIBILITY):
  3284 
  3285   list_all_Nil       now named list_all.simps(1)
  3286   list_all_Cons      now named list_all.simps(2)
  3287   list_all_conv      now named list_all_iff
  3288   set_mem_eq         now named mem_iff
  3289 
  3290 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3291 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3292 
  3293 
  3294 *** HOL-Complex ***
  3295 
  3296 * Theory RealDef: better support for embedding natural numbers and
  3297 integers in the reals.
  3298 
  3299 The following theorems have been eliminated or modified
  3300 (INCOMPATIBILITY):
  3301 
  3302   exp_ge_add_one_self  now requires no hypotheses
  3303   real_of_int_add      reversed direction of equality (use [symmetric])
  3304   real_of_int_minus    reversed direction of equality (use [symmetric])
  3305   real_of_int_diff     reversed direction of equality (use [symmetric])
  3306   real_of_int_mult     reversed direction of equality (use [symmetric])
  3307 
  3308 * Theory RComplete: expanded support for floor and ceiling functions.
  3309 
  3310 * Theory Ln is new, with properties of the natural logarithm
  3311 
  3312 * Hyperreal: There is a new type constructor "star" for making
  3313 nonstandard types.  The old type names are now type synonyms:
  3314 
  3315   hypreal = real star
  3316   hypnat = nat star
  3317   hcomplex = complex star
  3318 
  3319 * Hyperreal: Many groups of similarly-defined constants have been
  3320 replaced by polymorphic versions (INCOMPATIBILITY):
  3321 
  3322   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3323 
  3324   starset      <-- starsetNat, starsetC
  3325   *s*          <-- *sNat*, *sc*
  3326   starset_n    <-- starsetNat_n, starsetC_n
  3327   *sn*         <-- *sNatn*, *scn*
  3328   InternalSets <-- InternalNatSets, InternalCSets
  3329 
  3330   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3331   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3332   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3333   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3334   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3335 
  3336 * Hyperreal: Many type-specific theorems have been removed in favor of
  3337 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3338 
  3339   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3340   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3341   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3342   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3343   right_minus <-- hypreal_add_minus
  3344   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3345   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3346   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3347   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3348   mult_1_right <-- hcomplex_mult_one_right
  3349   mult_zero_left <-- hcomplex_mult_zero_left
  3350   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3351   right_distrib <-- hypnat_add_mult_distrib2
  3352   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3353   right_inverse <-- hypreal_mult_inverse
  3354   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3355   order_refl <-- {hypreal,hypnat}_le_refl
  3356   order_trans <-- {hypreal,hypnat}_le_trans
  3357   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3358   order_less_le <-- {hypreal,hypnat}_less_le
  3359   linorder_linear <-- {hypreal,hypnat}_le_linear
  3360   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3361   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3362   add_nonneg_nonneg <-- hypreal_le_add_order
  3363 
  3364 * Hyperreal: Separate theorems having to do with type-specific
  3365 versions of constants have been merged into theorems that apply to the
  3366 new polymorphic constants (INCOMPATIBILITY):
  3367 
  3368   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3369   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3370   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3371   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3372   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3373   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3374   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3375   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3376   STAR_diff <-- {STAR,STARC}_diff
  3377   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3378     STARC_hcomplex_of_complex}_image_subset
  3379   starset_n_Un <-- starset{Nat,C}_n_Un
  3380   starset_n_Int <-- starset{Nat,C}_n_Int
  3381   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3382   starset_n_diff <-- starset{Nat,C}_n_diff
  3383   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3384   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3385   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3386   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3387   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3388   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3389   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3390   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3391   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3392   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3393   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3394   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3395   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3396   starfun_diff <-- starfun{C,RC,CR}_diff
  3397   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3398   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3399   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3400   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3401   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3402   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3403   starfun_Id <-- starfunC_Id
  3404   starfun_approx <-- starfun{Nat,CR}_approx
  3405   starfun_capprox <-- starfun{C,RC}_capprox
  3406   starfun_abs <-- starfunNat_rabs
  3407   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3408   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3409   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3410   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3411   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3412   starfun_add_approx <-- starfunCR_add_approx
  3413   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3414   starfun_divide <-- starfun{C,CR,RC}_divide
  3415   starfun_n <-- starfun{Nat,C}_n
  3416   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3417   starfun_n_add <-- starfun{Nat,C}_n_add
  3418   starfun_n_add_minus <-- starfunNat_n_add_minus
  3419   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3420   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3421   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3422 
  3423   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3424   star_n_minus <-- {hypreal,hcomplex}_minus
  3425   star_n_diff <-- {hypreal,hcomplex}_diff
  3426   star_n_mult <-- {hypreal,hcomplex}_mult
  3427   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3428   star_n_le <-- {hypreal,hypnat}_le
  3429   star_n_less <-- {hypreal,hypnat}_less
  3430   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3431   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3432   star_n_abs <-- hypreal_hrabs
  3433   star_n_divide <-- hcomplex_divide
  3434 
  3435   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3436   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3437   star_of_diff <-- hypreal_of_real_diff
  3438   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3439   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3440   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3441   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3442   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3443   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3444   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3445   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3446   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3447   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3448   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3449   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3450   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3451   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3452   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3453   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3454   star_of_power <-- hypreal_of_real_power
  3455   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3456 
  3457 * Hyperreal: new method "transfer" that implements the transfer
  3458 principle of nonstandard analysis. With a subgoal that mentions
  3459 nonstandard types like "'a star", the command "apply transfer"
  3460 replaces it with an equivalent one that mentions only standard types.
  3461 To be successful, all free variables must have standard types; non-
  3462 standard variables must have explicit universal quantifiers.
  3463 
  3464 * Hyperreal: A theory of Taylor series.
  3465 
  3466 
  3467 *** HOLCF ***
  3468 
  3469 * Discontinued special version of 'constdefs' (which used to support
  3470 continuous functions) in favor of the general Pure one with full
  3471 type-inference.
  3472 
  3473 * New simplification procedure for solving continuity conditions; it
  3474 is much faster on terms with many nested lambda abstractions (cubic
  3475 instead of exponential time).
  3476 
  3477 * New syntax for domain package: selector names are now optional.
  3478 Parentheses should be omitted unless argument is lazy, for example:
  3479 
  3480   domain 'a stream = cons "'a" (lazy "'a stream")
  3481 
  3482 * New command 'fixrec' for defining recursive functions with pattern
  3483 matching; defining multiple functions with mutual recursion is also
  3484 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3485 sinr, or any data constructor defined by the domain package. The given
  3486 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3487 syntax and examples.
  3488 
  3489 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3490 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3491 but the proof obligation additionally includes an admissibility
  3492 requirement. The packages generate instances of class cpo or pcpo,
  3493 with continuity and strictness theorems for Rep and Abs.
  3494 
  3495 * HOLCF: Many theorems have been renamed according to a more standard naming
  3496 scheme (INCOMPATIBILITY):
  3497 
  3498   foo_inject:  "foo$x = foo$y ==> x = y"
  3499   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3500   foo_less:    "(foo$x << foo$y) = (x << y)"
  3501   foo_strict:  "foo$UU = UU"
  3502   foo_defined: "... ==> foo$x ~= UU"
  3503   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3504 
  3505 
  3506 *** ZF ***
  3507 
  3508 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3509 including the First Isomorphism Theorem (on quotienting by the kernel
  3510 of a homomorphism).
  3511 
  3512 * ZF/Simplifier: install second copy of type solver that actually
  3513 makes use of TC rules declared to Isar proof contexts (or locales);
  3514 the old version is still required for ML proof scripts.
  3515 
  3516 
  3517 *** Cube ***
  3518 
  3519 * Converted to Isar theory format; use locales instead of axiomatic
  3520 theories.
  3521 
  3522 
  3523 *** ML ***
  3524 
  3525 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3526 for ||>, ||>>, |>>,
  3527 
  3528 * Pure/library.ML no longer defines its own option datatype, but uses
  3529 that of the SML basis, which has constructors NONE and SOME instead of
  3530 None and Some, as well as exception Option.Option instead of OPTION.
  3531 The functions the, if_none, is_some, is_none have been adapted
  3532 accordingly, while Option.map replaces apsome.
  3533 
  3534 * Pure/library.ML: the exception LIST has been given up in favour of
  3535 the standard exceptions Empty and Subscript, as well as
  3536 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3537 superceded by the standard hd and tl functions etc.
  3538 
  3539 A number of basic list functions are no longer exported to the ML
  3540 toplevel, as they are variants of predefined functions.  The following
  3541 suggests how one can translate existing code:
  3542 
  3543     rev_append xs ys = List.revAppend (xs, ys)
  3544     nth_elem (i, xs) = List.nth (xs, i)
  3545     last_elem xs = List.last xs
  3546     flat xss = List.concat xss
  3547     seq fs = List.app fs
  3548     partition P xs = List.partition P xs
  3549     mapfilter f xs = List.mapPartial f xs
  3550 
  3551 * Pure/library.ML: several combinators for linear functional
  3552 transformations, notably reverse application and composition:
  3553 
  3554   x |> f                f #> g
  3555   (x, y) |-> f          f #-> g
  3556 
  3557 * Pure/library.ML: introduced/changed precedence of infix operators:
  3558 
  3559   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3560   infix 2 ?;
  3561   infix 3 o oo ooo oooo;
  3562   infix 4 ~~ upto downto;
  3563 
  3564 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3565 infix operators.
  3566 
  3567 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3568 fold_map support linear functional transformations and nesting.  For
  3569 example:
  3570 
  3571   fold f [x1, ..., xN] y =
  3572     y |> f x1 |> ... |> f xN
  3573 
  3574   (fold o fold) f [xs1, ..., xsN] y =
  3575     y |> fold f xs1 |> ... |> fold f xsN
  3576 
  3577   fold f [x1, ..., xN] =
  3578     f x1 #> ... #> f xN
  3579 
  3580   (fold o fold) f [xs1, ..., xsN] =
  3581     fold f xs1 #> ... #> fold f xsN
  3582 
  3583 * Pure/library.ML: the following selectors on type 'a option are
  3584 available:
  3585 
  3586   the:               'a option -> 'a  (*partial*)
  3587   these:             'a option -> 'a  where 'a = 'b list
  3588   the_default: 'a -> 'a option -> 'a
  3589   the_list:          'a option -> 'a list
  3590 
  3591 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3592 basic operations for association lists, following natural argument
  3593 order; moreover the explicit equality predicate passed here avoids
  3594 potentially expensive polymorphic runtime equality checks.
  3595 The old functions may be expressed as follows:
  3596 
  3597   assoc = uncurry (AList.lookup (op =))
  3598   assocs = these oo AList.lookup (op =)
  3599   overwrite = uncurry (AList.update (op =)) o swap
  3600 
  3601 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3602 
  3603   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3604   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3605 
  3606 replacing make_keylist and keyfilter (occassionally used)
  3607 Naive rewrites:
  3608 
  3609   make_keylist = AList.make
  3610   keyfilter = AList.find (op =)
  3611 
  3612 * eq_fst and eq_snd now take explicit equality parameter, thus
  3613   avoiding eqtypes. Naive rewrites:
  3614 
  3615     eq_fst = eq_fst (op =)
  3616     eq_snd = eq_snd (op =)
  3617 
  3618 * Removed deprecated apl and apr (rarely used).
  3619   Naive rewrites:
  3620 
  3621     apl (n, op) =>>= curry op n
  3622     apr (op, m) =>>= fn n => op (n, m)
  3623 
  3624 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3625 provides a reasonably efficient light-weight implementation of sets as
  3626 lists.
  3627 
  3628 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3629 few new operations; existing lookup and update are now curried to
  3630 follow natural argument order (for use with fold etc.);
  3631 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3632 
  3633 * Pure/General: output via the Isabelle channels of
  3634 writeln/warning/error etc. is now passed through Output.output, with a
  3635 hook for arbitrary transformations depending on the print_mode
  3636 (cf. Output.add_mode -- the first active mode that provides a output
  3637 function wins).  Already formatted output may be embedded into further
  3638 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3639 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3640 accommodate easy composition of diagnostic messages etc.  Programmers
  3641 rarely need to care about Output.output or Output.raw at all, with
  3642 some notable exceptions: Output.output is required when bypassing the
  3643 standard channels (writeln etc.), or in token translations to produce
  3644 properly formatted results; Output.raw is required when capturing
  3645 already output material that will eventually be presented to the user
  3646 a second time.  For the default print mode, both Output.output and
  3647 Output.raw have no effect.
  3648 
  3649 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3650 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3651 cumulative results are displayed at the end of a batch session.
  3652 
  3653 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3654 replaced by File.platform_path and File.shell_path (with appropriate
  3655 hooks).  This provides a clean interface for unusual systems where the
  3656 internal and external process view of file names are different.
  3657 
  3658 * Pure: more efficient orders for basic syntactic entities: added
  3659 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3660 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3661 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3662 orders now -- potential INCOMPATIBILITY for code that depends on a
  3663 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3664 Library.sort_strings on result).
  3665 
  3666 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3667 fold_types traverse types/terms from left to right, observing natural
  3668 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3669 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3670 
  3671 * Pure: name spaces have been refined, with significant changes of the
  3672 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3673 to extern(_table).  The plain name entry path is superceded by a
  3674 general 'naming' context, which also includes the 'policy' to produce
  3675 a fully qualified name and external accesses of a fully qualified
  3676 name; NameSpace.extend is superceded by context dependent
  3677 Sign.declare_name.  Several theory and proof context operations modify
  3678 the naming context.  Especially note Theory.restore_naming and
  3679 ProofContext.restore_naming to get back to a sane state; note that
  3680 Theory.add_path is no longer sufficient to recover from
  3681 Theory.absolute_path in particular.
  3682 
  3683 * Pure: new flags short_names (default false) and unique_names
  3684 (default true) for controlling output of qualified names.  If
  3685 short_names is set, names are printed unqualified.  If unique_names is
  3686 reset, the name prefix is reduced to the minimum required to achieve
  3687 the original result when interning again, even if there is an overlap
  3688 with earlier declarations.
  3689 
  3690 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3691 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3692 (useful for printing error messages).  INCOMPATIBILITY.
  3693 
  3694 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3695 Theory.theory are now identified, referring to the universal
  3696 Context.theory (see Pure/context.ML).  Actual signature and theory
  3697 content is managed as theory data.  The old code and interfaces were
  3698 spread over many files and structures; the new arrangement introduces
  3699 considerable INCOMPATIBILITY to gain more clarity:
  3700 
  3701   Context -- theory management operations (name, identity, inclusion,
  3702     parents, ancestors, merge, etc.), plus generic theory data;
  3703 
  3704   Sign -- logical signature and syntax operations (declaring consts,
  3705     types, etc.), plus certify/read for common entities;
  3706 
  3707   Theory -- logical theory operations (stating axioms, definitions,
  3708     oracles), plus a copy of logical signature operations (consts,
  3709     types, etc.); also a few basic management operations (Theory.copy,
  3710     Theory.merge, etc.)
  3711 
  3712 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3713 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3714 for convenience -- they merely return the theory.
  3715 
  3716 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3717 
  3718 * Pure: the Isar proof context type is already defined early in Pure
  3719 as Context.proof (note that ProofContext.context and Proof.context are
  3720 aliases, where the latter is the preferred name).  This enables other
  3721 Isabelle components to refer to that type even before Isar is present.
  3722 
  3723 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3724 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3725 any of these kinds.  For example, Sign.intern typeK is now
  3726 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3727 Theory.hide_types.  Also note that former
  3728 Theory.hide_classes/types/consts are now
  3729 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3730 internalize their arguments!  INCOMPATIBILITY.
  3731 
  3732 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3733 datatype thmref (with constructors Name and NameSelection) instead of
  3734 plain string -- INCOMPATIBILITY;
  3735 
  3736 * Pure: cases produced by proof methods specify options, where NONE
  3737 means to remove case bindings -- INCOMPATIBILITY in
  3738 (RAW_)METHOD_CASES.
  3739 
  3740 * Pure: the following operations retrieve axioms or theorems from a
  3741 theory node or theory hierarchy, respectively:
  3742 
  3743   Theory.axioms_of: theory -> (string * term) list
  3744   Theory.all_axioms_of: theory -> (string * term) list
  3745   PureThy.thms_of: theory -> (string * thm) list
  3746   PureThy.all_thms_of: theory -> (string * thm) list
  3747 
  3748 * Pure: print_tac now outputs the goal through the trace channel.
  3749 
  3750 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3751 Reference Toplevel.debug (default false) controls detailed printing
  3752 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3753 controls execution profiling -- set to 1 for time and 2 for space
  3754 (both increase the runtime).
  3755 
  3756 * Isar session: The initial use of ROOT.ML is now always timed,
  3757 i.e. the log will show the actual process times, in contrast to the
  3758 elapsed wall-clock time that the outer shell wrapper produces.
  3759 
  3760 * Simplifier: improved handling of bound variables (nameless
  3761 representation, avoid allocating new strings).  Simprocs that invoke
  3762 the Simplifier recursively should use Simplifier.inherit_bounds to
  3763 avoid local name clashes.  Failure to do so produces warnings
  3764 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3765 for further details.
  3766 
  3767 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3768 bindings for all theorems stored within a given theory; this may help
  3769 in porting non-Isar theories to Isar ones, while keeping ML proof
  3770 scripts for the time being.
  3771 
  3772 * ML operator HTML.with_charset specifies the charset begin used for
  3773 generated HTML files.  For example:
  3774 
  3775   HTML.with_charset "utf-8" use_thy "Hebrew";
  3776   HTML.with_charset "utf-8" use_thy "Chinese";
  3777 
  3778 
  3779 *** System ***
  3780 
  3781 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3782 isabelle, isatool etc.).
  3783 
  3784 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3785 isatool doc, isatool mkdir, display_drafts etc.).
  3786 
  3787 * isatool usedir: option -f allows specification of the ML file to be
  3788 used by Isabelle; default is ROOT.ML.
  3789 
  3790 * New isatool version outputs the version identifier of the Isabelle
  3791 distribution being used.
  3792 
  3793 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3794 (containing Boolean satisfiability problems) into Isabelle/HOL
  3795 theories.
  3796 
  3797 
  3798 
  3799 New in Isabelle2004 (April 2004)
  3800 --------------------------------
  3801 
  3802 *** General ***
  3803 
  3804 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3805   Replaces linorder.ML.
  3806 
  3807 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3808   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3809   (\<a>...\<z>), are now considered normal letters, and can therefore
  3810   be used anywhere where an ASCII letter (a...zA...Z) has until
  3811   now. COMPATIBILITY: This obviously changes the parsing of some
  3812   terms, especially where a symbol has been used as a binder, say
  3813   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3814   as an identifier.  Fix it by inserting a space around former
  3815   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3816   existing theory and ML files.
  3817 
  3818 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3819 
  3820 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3821   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3822   a normal (but invisible) letter. For multiple letter subscripts repeat
  3823   \<^isub> like this: x\<^isub>1\<^isub>2.
  3824 
  3825 * Pure: There are now sub-/superscripts that can span more than one
  3826   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3827   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3828   superscript. The new control characters are not identifier parts.
  3829 
  3830 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3831   content of "..." to the latex file instead of \isacntrl... . The "..."
  3832   may consist of any printable characters excluding the end bracket >.
  3833 
  3834 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3835   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3836   declare constants "final", which prevents their being given a definition
  3837   later.  It is useful for constants whose behaviour is fixed axiomatically
  3838   rather than definitionally, such as the meta-logic connectives.
  3839 
  3840 * Pure: 'instance' now handles general arities with general sorts
  3841   (i.e. intersections of classes),
  3842 
  3843 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3844   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3845   It can be changed to alter the colors/layout of generated pages.
  3846 
  3847 
  3848 *** Isar ***
  3849 
  3850 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3851   cut_tac, subgoal_tac and thin_tac:
  3852   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3853     locales are no longer forced to write Isar proof scripts.
  3854     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3855     emulations.
  3856   - INCOMPATIBILITY: names of variables to be instantiated may no
  3857     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3858     This is consistent with the instantiation attribute "where".
  3859 
  3860 * Attributes "where" and "of":
  3861   - Now take type variables of instantiated theorem into account when reading
  3862     the instantiation string.  This fixes a bug that caused instantiated
  3863     theorems to have too special types in some circumstances.
  3864   - "where" permits explicit instantiations of type variables.
  3865 
  3866 * Calculation commands "moreover" and "also" no longer interfere with
  3867   current facts ("this"), admitting arbitrary combinations with "then"
  3868   and derived forms.
  3869 
  3870 * Locales:
  3871   - Goal statements involving the context element "includes" no longer
  3872     generate theorems with internal delta predicates (those ending on
  3873     "_axioms") in the premise.
  3874     Resolve particular premise with <locale>.intro to obtain old form.
  3875   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3876     specification and "includes" elements in goal statement.
  3877   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3878     [intro?] and [elim?] (respectively) by default.
  3879   - Experimental command for instantiation of locales in proof contexts:
  3880         instantiate <label>[<attrs>]: <loc>
  3881     Instantiates locale <loc> and adds all its theorems to the current context
  3882     taking into account their attributes.  Label and attrs are optional
  3883     modifiers, like in theorem declarations.  If present, names of
  3884     instantiated theorems are qualified with <label>, and the attributes
  3885     <attrs> are applied after any attributes these theorems might have already.
  3886       If the locale has assumptions, a chained fact of the form
  3887     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3888     are derived.  The command does not support old-style locales declared
  3889     with "locale (open)".
  3890       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3891 
  3892 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3893   (Isar) contexts.
  3894 
  3895 
  3896 *** HOL ***
  3897 
  3898 * Proof import: new image HOL4 contains the imported library from
  3899   the HOL4 system with about 2500 theorems. It is imported by
  3900   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3901   can be used like any other Isabelle image.  See
  3902   HOL/Import/HOL/README for more information.
  3903 
  3904 * Simplifier:
  3905   - Much improved handling of linear and partial orders.
  3906     Reasoners for linear and partial orders are set up for type classes
  3907     "linorder" and "order" respectively, and are added to the default simpset
  3908     as solvers.  This means that the simplifier can build transitivity chains
  3909     to solve goals from the assumptions.
  3910   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3911     of blast or auto after simplification become unnecessary because the goal
  3912     is solved by simplification already.
  3913 
  3914 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3915     all proved in axiomatic type classes for semirings, rings and fields.
  3916 
  3917 * Numerics:
  3918   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3919     now formalized using the Ring_and_Field theory mentioned above.
  3920   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3921     than before, because now they are set up once in a generic manner.
  3922   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3923     Look for the general versions in Ring_and_Field (and Power if they concern
  3924     exponentiation).
  3925 
  3926 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3927 
  3928 * Records:
  3929   - Record types are now by default printed with their type abbreviation
  3930     instead of the list of all field types. This can be configured via
  3931     the reference "print_record_type_abbr".
  3932   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3933     (not enabled by default).
  3934   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3935     EX x. x = sel r to True (not enabled by default).
  3936   - Tactic "record_split_simp_tac" to split and simplify records added.
  3937 
  3938 * 'specification' command added, allowing for definition by
  3939   specification.  There is also an 'ax_specification' command that
  3940   introduces the new constants axiomatically.
  3941 
  3942 * arith(_tac) is now able to generate counterexamples for reals as well.
  3943 
  3944 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3945 
  3946 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3947   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3948 
  3949 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3950   matrix theory to linear programming.
  3951 
  3952 * Unions and Intersections:
  3953   The latex output syntax of UN and INT has been changed
  3954   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3955   i.e. the index formulae has become a subscript.
  3956   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3957 
  3958 * Unions and Intersections over Intervals:
  3959   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3960   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3961   like in normal math, and corresponding versions for < and for intersection.
  3962 
  3963 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3964   lexicographic dictonary ordering has been added as "lexord".
  3965 
  3966 * ML: the legacy theory structures Int and List have been removed. They had
  3967   conflicted with ML Basis Library structures having the same names.
  3968 
  3969 * 'refute' command added to search for (finite) countermodels.  Only works
  3970   for a fragment of HOL.  The installation of an external SAT solver is
  3971   highly recommended.  See "HOL/Refute.thy" for details.
  3972 
  3973 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3974   formulae under an assignment of free variables to random values.
  3975   In contrast to 'refute', it can deal with inductive datatypes,
  3976   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3977   for examples.
  3978 
  3979 
  3980 *** HOLCF ***
  3981 
  3982 * Streams now come with concatenation and are part of the HOLCF image
  3983 
  3984 
  3985 
  3986 New in Isabelle2003 (May 2003)
  3987 ------------------------------
  3988 
  3989 *** General ***
  3990 
  3991 * Provers/simplifier:
  3992 
  3993   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3994     Assumptions are now subject to complete mutual simplification,
  3995     not just from left to right. The simplifier now preserves
  3996     the order of assumptions.
  3997 
  3998     Potential INCOMPATIBILITY:
  3999 
  4000     -- simp sometimes diverges where the old version did
  4001        not, e.g. invoking simp on the goal
  4002 
  4003         [| P (f x); y = x; f x = f y |] ==> Q
  4004 
  4005        now gives rise to the infinite reduction sequence
  4006 
  4007         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4008 
  4009        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4010        kind of problem.
  4011 
  4012     -- Tactics combining classical reasoner and simplification (such as auto)
  4013        are also affected by this change, because many of them rely on
  4014        simp. They may sometimes diverge as well or yield a different numbers
  4015        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4016        in case of problems. Sometimes subsequent calls to the classical
  4017        reasoner will fail because a preceeding call to the simplifier too
  4018        eagerly simplified the goal, e.g. deleted redundant premises.
  4019 
  4020   - The simplifier trace now shows the names of the applied rewrite rules
  4021 
  4022   - You can limit the number of recursive invocations of the simplifier
  4023     during conditional rewriting (where the simplifie tries to solve the
  4024     conditions before applying the rewrite rule):
  4025     ML "simp_depth_limit := n"
  4026     where n is an integer. Thus you can force termination where previously
  4027     the simplifier would diverge.
  4028 
  4029   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4030 
  4031   - No longer aborts on failed congruence proof.  Instead, the
  4032     congruence is ignored.
  4033 
  4034 * Pure: New generic framework for extracting programs from constructive
  4035   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4036   as HOL/Extraction for some case studies.
  4037 
  4038 * Pure: The main goal of the proof state is no longer shown by default, only
  4039 the subgoals. This behaviour is controlled by a new flag.
  4040    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4041 (ML: Proof.show_main_goal).
  4042 
  4043 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4044 rules whose conclusion matches subgoal 1:
  4045       PG menu: Isabelle/Isar -> Show me -> matching rules
  4046 The rules are ordered by how closely they match the subgoal.
  4047 In particular, rules that solve a subgoal outright are displayed first
  4048 (or rather last, the way they are printed).
  4049 (ML: ProofGeneral.print_intros())
  4050 
  4051 * Pure: New flag trace_unify_fail causes unification to print
  4052 diagnostic information (PG: in trace buffer) when it fails. This is
  4053 useful for figuring out why single step proofs like rule, erule or
  4054 assumption failed.
  4055 
  4056 * Pure: Locale specifications now produce predicate definitions
  4057 according to the body of text (covering assumptions modulo local
  4058 definitions); predicate "loc_axioms" covers newly introduced text,
  4059 while "loc" is cumulative wrt. all included locale expressions; the
  4060 latter view is presented only on export into the global theory
  4061 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4062 on the old view without predicates;
  4063 
  4064 * Pure: predefined locales "var" and "struct" are useful for sharing
  4065 parameters (as in CASL, for example); just specify something like
  4066 ``var x + var y + struct M'' as import;
  4067 
  4068 * Pure: improved thms_containing: proper indexing of facts instead of
  4069 raw theorems; check validity of results wrt. current name space;
  4070 include local facts of proof configuration (also covers active
  4071 locales), cover fixed variables in index; may use "_" in term
  4072 specification; an optional limit for the number of printed facts may
  4073 be given (the default is 40);
  4074 
  4075 * Pure: disallow duplicate fact bindings within new-style theory files
  4076 (batch-mode only);
  4077 
  4078 * Provers: improved induct method: assumptions introduced by case
  4079 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4080 the goal statement); "foo" still refers to all facts collectively;
  4081 
  4082 * Provers: the function blast.overloaded has been removed: all constants
  4083 are regarded as potentially overloaded, which improves robustness in exchange
  4084 for slight decrease in efficiency;
  4085 
  4086 * Provers/linorder: New generic prover for transitivity reasoning over
  4087 linear orders.  Note: this prover is not efficient!
  4088 
  4089 * Isar: preview of problems to finish 'show' now produce an error
  4090 rather than just a warning (in interactive mode);
  4091 
  4092 
  4093 *** HOL ***
  4094 
  4095 * arith(_tac)
  4096 
  4097  - Produces a counter example if it cannot prove a goal.
  4098    Note that the counter example may be spurious if the goal is not a formula
  4099    of quantifier-free linear arithmetic.
  4100    In ProofGeneral the counter example appears in the trace buffer.
  4101 
  4102  - Knows about div k and mod k where k is a numeral of type nat or int.
  4103 
  4104  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4105    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4106    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4107 
  4108 * simp's arithmetic capabilities have been enhanced a bit: it now
  4109 takes ~= in premises into account (by performing a case split);
  4110 
  4111 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4112 are distributed over a sum of terms;
  4113 
  4114 * New tactic "trans_tac" and method "trans" instantiate
  4115 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4116 "<=", "<" and "=").
  4117 
  4118 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4119 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4120 
  4121 * 'typedef' command has new option "open" to suppress the set
  4122 definition;
  4123 
  4124 * functions Min and Max on finite sets have been introduced (theory
  4125 Finite_Set);
  4126 
  4127 * attribute [symmetric] now works for relations as well; it turns
  4128 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4129 
  4130 * induct over a !!-quantified statement (say !!x1..xn):
  4131   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4132 
  4133 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4134 %x. None. Warning: empty_def now refers to the previously hidden definition
  4135 of the empty set.
  4136 
  4137 * Algebra: formalization of classical algebra.  Intended as base for
  4138 any algebraic development in Isabelle.  Currently covers group theory
  4139 (up to Sylow's theorem) and ring theory (Universal Property of
  4140 Univariate Polynomials).  Contributions welcome;
  4141 
  4142 * GroupTheory: deleted, since its material has been moved to Algebra;
  4143 
  4144 * Complex: new directory of the complex numbers with numeric constants,
  4145 nonstandard complex numbers, and some complex analysis, standard and
  4146 nonstandard (Jacques Fleuriot);
  4147 
  4148 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4149 
  4150 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4151 Fleuriot);
  4152 
  4153 * Real/HahnBanach: updated and adapted to locales;
  4154 
  4155 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4156 Gray and Kramer);
  4157 
  4158 * UNITY: added the Meier-Sanders theory of progress sets;
  4159 
  4160 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4161 as abstract algorithms, instantiated to the JVM;
  4162 
  4163 * Bali: Java source language formalization. Type system, operational
  4164 semantics, axiomatic semantics. Supported language features:
  4165 classes, interfaces, objects,virtual methods, static methods,
  4166 static/instance fields, arrays, access modifiers, definite
  4167 assignment, exceptions.
  4168 
  4169 
  4170 *** ZF ***
  4171 
  4172 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4173 universe, etc.);
  4174 
  4175 * Main ZF: virtually all theories converted to new-style format;
  4176 
  4177 
  4178 *** ML ***
  4179 
  4180 * Pure: Tactic.prove provides sane interface for internal proofs;
  4181 omits the infamous "standard" operation, so this is more appropriate
  4182 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4183 
  4184 * Pure: improved error reporting of simprocs;
  4185 
  4186 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4187 up simprocs;
  4188 
  4189 
  4190 *** Document preparation ***
  4191 
  4192 * uses \par instead of \\ for line breaks in theory text. This may
  4193 shift some page breaks in large documents. To get the old behaviour
  4194 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4195 
  4196 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4197 other packages
  4198 
  4199 * \<euro> now needs package babel/greek instead of marvosym (which
  4200 broke \Rightarrow)
  4201 
  4202 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4203 textcomp package)
  4204 
  4205 
  4206 
  4207 New in Isabelle2002 (March 2002)
  4208 --------------------------------
  4209 
  4210 *** Document preparation ***
  4211 
  4212 * greatly simplified document preparation setup, including more
  4213 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4214 instructive isatool mkdir; users should basically be able to get
  4215 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4216 users may run a separate document processing stage manually like this:
  4217 "isatool usedir -D output HOL Test && isatool document Test/output";
  4218 
  4219 * theory dependency graph may now be incorporated into documents;
  4220 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4221 with \includegraphics of LaTeX;
  4222 
  4223 * proper spacing of consecutive markup elements, especially text
  4224 blocks after section headings;
  4225 
  4226 * support bold style (for single symbols only), input syntax is like
  4227 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4228 
  4229 * \<bullet> is now output as bold \cdot by default, which looks much
  4230 better in printed text;
  4231 
  4232 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4233 note that these symbols are currently unavailable in Proof General /
  4234 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4235 
  4236 * isatool latex no longer depends on changed TEXINPUTS, instead
  4237 isatool document copies the Isabelle style files to the target
  4238 location;
  4239 
  4240 
  4241 *** Isar ***
  4242 
  4243 * Pure/Provers: improved proof by cases and induction;
  4244   - 'case' command admits impromptu naming of parameters (such as
  4245     "case (Suc n)");
  4246   - 'induct' method divinates rule instantiation from the inductive
  4247     claim; no longer requires excessive ?P bindings for proper
  4248     instantiation of cases;
  4249   - 'induct' method properly enumerates all possibilities of set/type
  4250     rules; as a consequence facts may be also passed through *type*
  4251     rules without further ado;
  4252   - 'induct' method now derives symbolic cases from the *rulified*
  4253     rule (before it used to rulify cases stemming from the internal
  4254     atomized version); this means that the context of a non-atomic
  4255     statement becomes is included in the hypothesis, avoiding the
  4256     slightly cumbersome show "PROP ?case" form;
  4257   - 'induct' may now use elim-style induction rules without chaining
  4258     facts, using ``missing'' premises from the goal state; this allows
  4259     rules stemming from inductive sets to be applied in unstructured
  4260     scripts, while still benefitting from proper handling of non-atomic
  4261     statements; NB: major inductive premises need to be put first, all
  4262     the rest of the goal is passed through the induction;
  4263   - 'induct' proper support for mutual induction involving non-atomic
  4264     rule statements (uses the new concept of simultaneous goals, see
  4265     below);
  4266   - append all possible rule selections, but only use the first
  4267     success (no backtracking);
  4268   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4269   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4270   - added 'print_induct_rules' (covered by help item in recent Proof
  4271     General versions);
  4272   - moved induct/cases attributes to Pure, methods to Provers;
  4273   - generic method setup instantiated for FOL and HOL;
  4274 
  4275 * Pure: support multiple simultaneous goal statements, for example
  4276 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4277 meta-level mechanism, this acts as if several individual goals had
  4278 been stated separately; in particular common proof methods need to be
  4279 repeated in order to cover all claims; note that a single elimination
  4280 step is *not* sufficient to establish the two conjunctions, so this
  4281 fails:
  4282 
  4283   assume "A & B" then have A and B ..   (*".." fails*)
  4284 
  4285 better use "obtain" in situations as above; alternative refer to
  4286 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4287 
  4288 * Pure: proper integration with ``locales''; unlike the original
  4289 version by Florian Kammller, Isar locales package high-level proof
  4290 contexts rather than raw logical ones (e.g. we admit to include
  4291 attributes everywhere); operations on locales include merge and
  4292 rename; support for implicit arguments (``structures''); simultaneous
  4293 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4294 some examples;
  4295 
  4296 * Pure: the following commands have been ``localized'', supporting a
  4297 target locale specification "(in name)": 'lemma', 'theorem',
  4298 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4299 stored both within the locale and at the theory level (exported and
  4300 qualified by the locale name);
  4301 
  4302 * Pure: theory goals may now be specified in ``long'' form, with
  4303 ad-hoc contexts consisting of arbitrary locale elements. for example
  4304 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4305 definitions may be given, too); the result is a meta-level rule with
  4306 the context elements being discharged in the obvious way;
  4307 
  4308 * Pure: new proof command 'using' allows to augment currently used
  4309 facts after a goal statement ('using' is syntactically analogous to
  4310 'apply', but acts on the goal's facts only); this allows chained facts
  4311 to be separated into parts given before and after a claim, as in
  4312 ``from a and b have C using d and e <proof>'';
  4313 
  4314 * Pure: renamed "antecedent" case to "rule_context";
  4315 
  4316 * Pure: new 'judgment' command records explicit information about the
  4317 object-logic embedding (used by several tools internally); no longer
  4318 use hard-wired "Trueprop";
  4319 
  4320 * Pure: added 'corollary' command;
  4321 
  4322 * Pure: fixed 'token_translation' command;
  4323 
  4324 * Pure: removed obsolete 'exported' attribute;
  4325 
  4326 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4327 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4328 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4329 
  4330 * Pure: method 'atomize' presents local goal premises as object-level
  4331 statements (atomic meta-level propositions); setup controlled via
  4332 rewrite rules declarations of 'atomize' attribute; example
  4333 application: 'induct' method with proper rule statements in improper
  4334 proof *scripts*;
  4335 
  4336 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4337 now consider the syntactic context of assumptions, giving a better
  4338 chance to get type-inference of the arguments right (this is
  4339 especially important for locales);
  4340 
  4341 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4342 mode;
  4343 
  4344 * Pure/obtain: the formal conclusion "thesis", being marked as
  4345 ``internal'', may no longer be reference directly in the text;
  4346 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4347 situations;
  4348 
  4349 * Pure: generic 'sym' attribute which declares a rule both as pure
  4350 'elim?' and for the 'symmetric' operation;
  4351 
  4352 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4353 text; the fixed correlation with particular command syntax has been
  4354 discontinued;
  4355 
  4356 * Pure: new method 'rules' is particularly well-suited for proof
  4357 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4358 but often produces more compact proof terms with less detours;
  4359 
  4360 * Pure/Provers/classical: simplified integration with pure rule
  4361 attributes and methods; the classical "intro?/elim?/dest?"
  4362 declarations coincide with the pure ones; the "rule" method no longer
  4363 includes classically swapped intros; "intro" and "elim" methods no
  4364 longer pick rules from the context; also got rid of ML declarations
  4365 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4366 INCOMPATIBILITY;
  4367 
  4368 * Provers/classical: attribute 'swapped' produces classical inversions
  4369 of introduction rules;
  4370 
  4371 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4372 rules instead of full simplifier context; 'iff' attribute handles
  4373 conditional rules;
  4374 
  4375 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4376 
  4377 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4378 "(permissive)" option to recover old behavior;
  4379 
  4380 * HOL: 'inductive' no longer features separate (collective) attributes
  4381 for 'intros' (was found too confusing);
  4382 
  4383 * HOL: properly declared induction rules less_induct and
  4384 wf_induct_rule;
  4385 
  4386 
  4387 *** HOL ***
  4388 
  4389 * HOL: moved over to sane numeral syntax; the new policy is as
  4390 follows:
  4391 
  4392   - 0 and 1 are polymorphic constants, which are defined on any
  4393   numeric type (nat, int, real etc.);
  4394 
  4395   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4396   binary representation internally;
  4397 
  4398   - type nat has special constructor Suc, and generally prefers Suc 0
  4399   over 1::nat and Suc (Suc 0) over 2::nat;
  4400 
  4401 This change may cause significant problems of INCOMPATIBILITY; here
  4402 are some hints on converting existing sources:
  4403 
  4404   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4405   entities, so expressions involving "-" (unary or binary minus) need
  4406   to be spaced properly;
  4407 
  4408   - existing occurrences of "1" may need to be constraint "1::nat" or
  4409   even replaced by Suc 0; similar for old "2";
  4410 
  4411   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4412 
  4413   - remove all special provisions on numerals in proofs;
  4414 
  4415 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4416 representation (depends on bin_arith_simps in the default context);
  4417 
  4418 * HOL: symbolic syntax for x^2 (numeral 2);
  4419 
  4420 * HOL: the class of all HOL types is now called "type" rather than
  4421 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4422 in axclass/classes, instance/arities, and (usually rare) occurrences
  4423 in typings (of consts etc.); internally the class is called
  4424 "HOL.type", ML programs should refer to HOLogic.typeS;
  4425 
  4426 * HOL/record package improvements:
  4427   - new derived operations "fields" to build a partial record section,
  4428     "extend" to promote a fixed record to a record scheme, and
  4429     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4430     declared as simp by default;
  4431   - shared operations ("more", "fields", etc.) now need to be always
  4432     qualified) --- potential INCOMPATIBILITY;
  4433   - removed "make_scheme" operations (use "make" with "extend") --
  4434     INCOMPATIBILITY;
  4435   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4436   - provides cases/induct rules for use with corresponding Isar
  4437     methods (for concrete records, record schemes, concrete more
  4438     parts, and schematic more parts -- in that order);
  4439   - internal definitions directly based on a light-weight abstract
  4440     theory of product types over typedef rather than datatype;
  4441 
  4442 * HOL: generic code generator for generating executable ML code from
  4443 specifications; specific support for HOL constructs such as inductive
  4444 datatypes and sets, as well as recursive functions; can be invoked
  4445 via 'generate_code' theory section;
  4446 
  4447 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4448 
  4449 * HOL: consolidated and renamed several theories.  In particular:
  4450         Ord.thy has been absorbed into HOL.thy
  4451         String.thy has been absorbed into List.thy
  4452 
  4453 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4454 (beware of argument permutation!);
  4455 
  4456 * HOL: linorder_less_split superseded by linorder_cases;
  4457 
  4458 * HOL/List: "nodups" renamed to "distinct";
  4459 
  4460 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4461 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4462   - Ex_def has changed, now need to use some_eq_ex
  4463 
  4464 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4465 in this (rare) case use:
  4466 
  4467   delSWrapper "split_all_tac"
  4468   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4469 
  4470 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4471 MAY FAIL;
  4472 
  4473 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4474 Isabelle's type classes, ^ on functions and relations has too general
  4475 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4476 necessary to attach explicit type constraints;
  4477 
  4478 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4479 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4480 renamed accordingly (eg "compI" -> "rel_compI").
  4481 
  4482 * HOL: syntax translations now work properly with numerals and records
  4483 expressions;
  4484 
  4485 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4486 of "lam" -- INCOMPATIBILITY;
  4487 
  4488 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4489 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4490 renamed "Product_Type.unit";
  4491 
  4492 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4493 
  4494 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4495 the "cases" method);
  4496 
  4497 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4498 Florian Kammller);
  4499 
  4500 * HOL/IMP: updated and converted to new-style theory format; several
  4501 parts turned into readable document, with proper Isar proof texts and
  4502 some explanations (by Gerwin Klein);
  4503 
  4504 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4505 
  4506 * HOL-Hyperreal is now a logic image;
  4507 
  4508 
  4509 *** HOLCF ***
  4510 
  4511 * Isar: consts/constdefs supports mixfix syntax for continuous
  4512 operations;
  4513 
  4514 * Isar: domain package adapted to new-style theory format, e.g. see
  4515 HOLCF/ex/Dnat.thy;
  4516 
  4517 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4518 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4519 lift.induct_tac, always use UU instead of Undef;
  4520 
  4521 * HOLCF/IMP: updated and converted to new-style theory;
  4522 
  4523 
  4524 *** ZF ***
  4525 
  4526 * Isar: proper integration of logic-specific tools and packages,
  4527 including theory commands '(co)inductive', '(co)datatype',
  4528 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4529 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4530 
  4531 * theory Main no longer includes AC; for the Axiom of Choice, base
  4532 your theory on Main_ZFC;
  4533 
  4534 * the integer library now covers quotients and remainders, with many
  4535 laws relating division to addition, multiplication, etc.;
  4536 
  4537 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4538 typeless version of the formalism;
  4539 
  4540 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4541 format;
  4542 
  4543 * ZF/Induct: new directory for examples of inductive definitions,
  4544 including theory Multiset for multiset orderings; converted to
  4545 new-style theory format;
  4546 
  4547 * ZF: many new theorems about lists, ordinals, etc.;
  4548 
  4549 
  4550 *** General ***
  4551 
  4552 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4553 variable proof controls level of detail: 0 = no proofs (only oracle
  4554 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4555 also ref manual for further ML interfaces;
  4556 
  4557 * Pure/axclass: removed obsolete ML interface
  4558 goal_subclass/goal_arity;
  4559 
  4560 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4561 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4562 separate tokens, so expressions involving minus need to be spaced
  4563 properly;
  4564 
  4565 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4566 rather than "infixl" or "infixr";
  4567 
  4568 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4569 sort constraint specifications in type inference; e.g. "x::_::foo"
  4570 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4571 type variable);
  4572 
  4573 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4574 control output of nested => (types); the default behavior is
  4575 "type_brackets";
  4576 
  4577 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4578 tokens into AST constants;
  4579 
  4580 * Pure/syntax: prefer later declarations of translations and print
  4581 translation functions; potential INCOMPATIBILITY: need to reverse
  4582 multiple declarations for same syntax element constant;
  4583 
  4584 * Pure/show_hyps reset by default (in accordance to existing Isar
  4585 practice);
  4586 
  4587 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4588 addSafter;
  4589 
  4590 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4591 as well;
  4592 
  4593 * system: tested support for MacOS X; should be able to get Isabelle +
  4594 Proof General to work in a plain Terminal after installing Poly/ML
  4595 (e.g. from the Isabelle distribution area) and GNU bash alone
  4596 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4597 support requires further installations, e.g. from
  4598 http://fink.sourceforge.net/);
  4599 
  4600 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4601 
  4602 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4603 of 40 MB), cf. ML_OPTIONS;
  4604 
  4605 * system: Proof General keywords specification is now part of the
  4606 Isabelle distribution (see etc/isar-keywords.el);
  4607 
  4608 * system: support for persistent Proof General sessions (refrain from
  4609 outdating all loaded theories on startup); user may create writable
  4610 logic images like this: ``isabelle -q HOL Test'';
  4611 
  4612 * system: smart selection of Isabelle process versus Isabelle
  4613 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4614 run both "isabelle" and "Isabelle" even if file names are badly
  4615 damaged (executable inspects the case of the first letter of its own
  4616 name); added separate "isabelle-process" and "isabelle-interface";
  4617 
  4618 * system: refrain from any attempt at filtering input streams; no
  4619 longer support ``8bit'' encoding of old isabelle font, instead proper
  4620 iso-latin characters may now be used; the related isatools
  4621 "symbolinput" and "nonascii" have disappeared as well;
  4622 
  4623 * system: removed old "xterm" interface (the print modes "xterm" and
  4624 "xterm_color" are still available for direct use in a suitable
  4625 terminal);
  4626 
  4627 
  4628 
  4629 New in Isabelle99-2 (February 2001)
  4630 -----------------------------------
  4631 
  4632 *** Overview of INCOMPATIBILITIES ***
  4633 
  4634 * HOL: please note that theories in the Library and elsewhere often use the
  4635 new-style (Isar) format; to refer to their theorems in an ML script you must
  4636 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4637 
  4638 * HOL: inductive package no longer splits induction rule aggressively,
  4639 but only as far as specified by the introductions given; the old
  4640 format may be recovered via ML function complete_split_rule or attribute
  4641 'split_rule (complete)';
  4642 
  4643 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4644 gfp_Tarski to gfp_unfold;
  4645 
  4646 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4647 
  4648 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4649 relation); infix "^^" has been renamed "``"; infix "``" has been
  4650 renamed "`"; "univalent" has been renamed "single_valued";
  4651 
  4652 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4653 operation;
  4654 
  4655 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4656 
  4657 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4658 
  4659 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4660 consequence, it is no longer monotonic wrt. the local goal context
  4661 (which is now passed through the inductive cases);
  4662 
  4663 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4664 \<gg> to \<ggreater>;
  4665 
  4666 
  4667 *** Document preparation ***
  4668 
  4669 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4670 available: are "it" for near math-mode best-style output, "sl" for
  4671 slanted text style, and "tt" for plain type-writer; if no
  4672 \isabellestyle command is given, output is according to slanted
  4673 type-writer);
  4674 
  4675 * support sub/super scripts (for single symbols only), input syntax is
  4676 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4677 
  4678 * some more standard symbols; see Appendix A of the system manual for
  4679 the complete list of symbols defined in isabellesym.sty;
  4680 
  4681 * improved isabelle style files; more abstract symbol implementation
  4682 (should now use \isamath{...} and \isatext{...} in custom symbol
  4683 definitions);
  4684 
  4685 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4686 state; Note that presentation of goal states does not conform to
  4687 actual human-readable proof documents.  Please do not include goal
  4688 states into document output unless you really know what you are doing!
  4689 
  4690 * proper indentation of antiquoted output with proportional LaTeX
  4691 fonts;
  4692 
  4693 * no_document ML operator temporarily disables LaTeX document
  4694 generation;
  4695 
  4696 * isatool unsymbolize tunes sources for plain ASCII communication;
  4697 
  4698 
  4699 *** Isar ***
  4700 
  4701 * Pure: Isar now suffers initial goal statements to contain unbound
  4702 schematic variables (this does not conform to actual readable proof
  4703 documents, due to unpredictable outcome and non-compositional proof
  4704 checking); users who know what they are doing may use schematic goals
  4705 for Prolog-style synthesis of proven results;
  4706 
  4707 * Pure: assumption method (an implicit finishing) now handles actual
  4708 rules as well;
  4709 
  4710 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4711 initial goal, declare "that" only as Pure intro (only for single
  4712 steps); the "that" rule assumption may now be involved in implicit
  4713 finishing, thus ".." becomes a feasible for trivial obtains;
  4714 
  4715 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4716 instance proofs may be performed by "..";
  4717 
  4718 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4719 statements as well;
  4720 
  4721 * Pure: more robust selection of calculational rules;
  4722 
  4723 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4724 rule (as well as the assumption rule);
  4725 
  4726 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4727 lemmas, using the graph browser tool;
  4728 
  4729 * Pure: predict failure of "show" in interactive mode;
  4730 
  4731 * Pure: 'thms_containing' now takes actual terms as arguments;
  4732 
  4733 * HOL: improved method 'induct' --- now handles non-atomic goals
  4734 (potential INCOMPATIBILITY); tuned error handling;
  4735 
  4736 * HOL: cases and induct rules now provide explicit hints about the
  4737 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4738 any remaining facts are inserted into the goal verbatim;
  4739 
  4740 * HOL: local contexts (aka cases) may now contain term bindings as
  4741 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4742 the result to be shown in each case;
  4743 
  4744 * HOL: added 'recdef_tc' command;
  4745 
  4746 * isatool convert assists in eliminating legacy ML scripts;
  4747 
  4748 
  4749 *** HOL ***
  4750 
  4751 * HOL/Library: a collection of generic theories to be used together
  4752 with main HOL; the theory loader path already includes this directory
  4753 by default; the following existing theories have been moved here:
  4754 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4755 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4756 
  4757 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4758 modelling and verification task performed in Isabelle/HOL +
  4759 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4760 
  4761 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4762 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4763 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4764 'domain', this makes the theory consistent with mathematical
  4765 literature;
  4766 
  4767 * HOL basics: added overloaded operations "inverse" and "divide"
  4768 (infix "/"), syntax for generic "abs" operation, generic summation
  4769 operator \<Sum>;
  4770 
  4771 * HOL/typedef: simplified package, provide more useful rules (see also
  4772 HOL/subset.thy);
  4773 
  4774 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4775 now expressed as a proper nested rule (old-style tactic scripts may
  4776 require atomize_strip_tac to cope with non-atomic premises);
  4777 
  4778 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4779 to "split_conv" (old name still available for compatibility);
  4780 
  4781 * HOL: improved concrete syntax for strings (e.g. allows translation
  4782 rules with string literals);
  4783 
  4784 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4785  and Fleuriot's mechanization of analysis, including the transcendental
  4786  functions for the reals;
  4787 
  4788 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4789 
  4790 
  4791 *** CTT ***
  4792 
  4793 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4794 "lam" is displayed as TWO lambda-symbols
  4795 
  4796 * CTT: theory Main now available, containing everything (that is, Bool
  4797 and Arith);
  4798 
  4799 
  4800 *** General ***
  4801 
  4802 * Pure: the Simplifier has been implemented properly as a derived rule
  4803 outside of the actual kernel (at last!); the overall performance
  4804 penalty in practical applications is about 50%, while reliability of
  4805 the Isabelle inference kernel has been greatly improved;
  4806 
  4807 * print modes "brackets" and "no_brackets" control output of nested =>
  4808 (types) and ==> (props); the default behaviour is "brackets";
  4809 
  4810 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4811 as assumptions as well;
  4812 
  4813 * system: support Poly/ML 4.0;
  4814 
  4815 * system: isatool install handles KDE version 1 or 2;
  4816 
  4817 
  4818 
  4819 New in Isabelle99-1 (October 2000)
  4820 ----------------------------------
  4821 
  4822 *** Overview of INCOMPATIBILITIES ***
  4823 
  4824 * HOL: simplification of natural numbers is much changed; to partly
  4825 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4826 issue the following ML commands:
  4827 
  4828   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4829   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4830 
  4831 * HOL: simplification no longer dives into case-expressions; this is
  4832 controlled by "t.weak_case_cong" for each datatype t;
  4833 
  4834 * HOL: nat_less_induct renamed to less_induct;
  4835 
  4836 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4837 fixsome to patch .thy and .ML sources automatically;
  4838 
  4839   select_equality  -> some_equality
  4840   select_eq_Ex     -> some_eq_ex
  4841   selectI2EX       -> someI2_ex
  4842   selectI2         -> someI2
  4843   selectI          -> someI
  4844   select1_equality -> some1_equality
  4845   Eps_sym_eq       -> some_sym_eq_trivial
  4846   Eps_eq           -> some_eq_trivial
  4847 
  4848 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4849 
  4850 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4851 instead);
  4852 
  4853 * HOL: the recursion equations generated by 'recdef' are now called
  4854 f.simps instead of f.rules;
  4855 
  4856 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4857 
  4858 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4859 sometimes be needed;
  4860 
  4861 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4862 
  4863 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4864 
  4865 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4866 product is now "<*>" instead of "Times"; the lexicographic product is
  4867 now "<*lex*>" instead of "**";
  4868 
  4869 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4870 of main HOL, but was unused); better use HOL's datatype package;
  4871 
  4872 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4873 the old syntax may be recovered as follows:
  4874 
  4875   syntax (symbols)
  4876     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4877       (infixl "\\<oplus>" 100)
  4878 
  4879 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4880 
  4881 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4882 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4883 internally;
  4884 
  4885 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4886 changed from A/r to A//r;
  4887 
  4888 * ZF: new treatment of arithmetic (nat & int) may break some old
  4889 proofs;
  4890 
  4891 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4892 rulify -> rule_format, elimify -> elim_format, ...);
  4893 
  4894 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4895 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4896 should have to change intro!! to intro? only); replaced "delrule" by
  4897 "rule del";
  4898 
  4899 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4900 
  4901 * Provers: strengthened force_tac by using new first_best_tac;
  4902 
  4903 * LaTeX document preparation: several changes of isabelle.sty (see
  4904 lib/texinputs);
  4905 
  4906 
  4907 *** Document preparation ***
  4908 
  4909 * formal comments (text blocks etc.) in new-style theories may now
  4910 contain antiquotations of thm/prop/term/typ/text to be presented
  4911 according to latex print mode; concrete syntax is like this:
  4912 @{term[show_types] "f(x) = a + x"};
  4913 
  4914 * isatool mkdir provides easy setup of Isabelle session directories,
  4915 including proper document sources;
  4916 
  4917 * generated LaTeX sources are now deleted after successful run
  4918 (isatool document -c); may retain a copy somewhere else via -D option
  4919 of isatool usedir;
  4920 
  4921 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4922 style files, achieving self-contained LaTeX sources and simplifying
  4923 LaTeX debugging;
  4924 
  4925 * old-style theories now produce (crude) LaTeX output as well;
  4926 
  4927 * browser info session directories are now self-contained (may be put
  4928 on WWW server seperately); improved graphs of nested sessions; removed
  4929 graph for 'all sessions';
  4930 
  4931 * several improvements in isabelle style files; \isabellestyle{it}
  4932 produces fake math mode output; \isamarkupheader is now \section by
  4933 default; see lib/texinputs/isabelle.sty etc.;
  4934 
  4935 
  4936 *** Isar ***
  4937 
  4938 * Isar/Pure: local results and corresponding term bindings are now
  4939 subject to Hindley-Milner polymorphism (similar to ML); this
  4940 accommodates incremental type-inference very nicely;
  4941 
  4942 * Isar/Pure: new derived language element 'obtain' supports
  4943 generalized existence reasoning;
  4944 
  4945 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4946 support accumulation of results, without applying any rules yet;
  4947 useful to collect intermediate results without explicit name
  4948 references, and for use with transitivity rules with more than 2
  4949 premises;
  4950 
  4951 * Isar/Pure: scalable support for case-analysis type proofs: new
  4952 'case' language element refers to local contexts symbolically, as
  4953 produced by certain proof methods; internally, case names are attached
  4954 to theorems as "tags";
  4955 
  4956 * Isar/Pure: theory command 'hide' removes declarations from
  4957 class/type/const name spaces;
  4958 
  4959 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4960 indicate potential overloading;
  4961 
  4962 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4963 
  4964 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4965 "{a,b,c}" instead of {a,b,c};
  4966 
  4967 * Isar/Pure now provides its own version of intro/elim/dest
  4968 attributes; useful for building new logics, but beware of confusion
  4969 with the version in Provers/classical;
  4970 
  4971 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4972 case name 'antecedent';
  4973 
  4974 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4975 to the current context is now done automatically);
  4976 
  4977 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4978 for definining proof methods in ML;
  4979 
  4980 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4981 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4982 most cases, one should have to change intro!! to intro? only);
  4983 replaced "delrule" by "rule del";
  4984 
  4985 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4986 'symmetric' attribute (the latter supercedes [RS sym]);
  4987 
  4988 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4989 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4990 well (including splits);
  4991 
  4992 * Isar/Provers: Simplifier and Classical methods now support all kind
  4993 of modifiers used in the past, including 'cong', 'iff', etc.
  4994 
  4995 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4996 of Simplifier and Classical reasoner);
  4997 
  4998 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4999 now support named cases; major packages (inductive, datatype, primrec,
  5000 recdef) support case names and properly name parameters;
  5001 
  5002 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5003 monotonicity conditions are extracted to be proven at end of
  5004 calculations;
  5005 
  5006 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5007 method anyway;
  5008 
  5009 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5010 split_if split_if_asm; datatype package provides theorems foo.splits =
  5011 foo.split foo.split_asm for each datatype;
  5012 
  5013 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5014 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5015 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5016 use "(cases (simplified))" method in proper proof texts);
  5017 
  5018 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5019 
  5020 * Isar: names of theorems etc. may be natural numbers as well;
  5021 
  5022 * Isar: 'pr' command: optional arguments for goals_limit and
  5023 ProofContext.prems_limit; no longer prints theory contexts, but only
  5024 proof states;
  5025 
  5026 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5027 additional print modes to be specified; e.g. "pr(latex)" will print
  5028 proof state according to the Isabelle LaTeX style;
  5029 
  5030 * Isar: improved support for emulating tactic scripts, including proof
  5031 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5032 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5033 (for HOL datatypes);
  5034 
  5035 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5036 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5037 'proof method scripts' have to be in depth-first order;
  5038 
  5039 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5040 
  5041 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5042 should instead use individual commands for printing items
  5043 (print_commands, print_methods etc.);
  5044 
  5045 * Isar: added 'nothing' --- the empty list of theorems;
  5046 
  5047 
  5048 *** HOL ***
  5049 
  5050 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5051 corresponding virtual machine and a specification of its bytecode
  5052 verifier and a lightweight bytecode verifier, including proofs of
  5053 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5054 Cornelia Pusch (see also the homepage of project Bali at
  5055 http://isabelle.in.tum.de/Bali/);
  5056 
  5057 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5058 Clemens Ballarin;
  5059 
  5060 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5061 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5062 Rasmussen;
  5063 
  5064 * HOL/Lattice: fundamental concepts of lattice theory and order
  5065 structures, including duals, properties of bounds versus algebraic
  5066 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5067 Theorem for complete lattices etc.; may also serve as a demonstration
  5068 for abstract algebraic reasoning using axiomatic type classes, and
  5069 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5070 
  5071 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5072 von Oheimb;
  5073 
  5074 * HOL/IMPP: extension of IMP with local variables and mutually
  5075 recursive procedures, by David von Oheimb;
  5076 
  5077 * HOL/Lambda: converted into new-style theory and document;
  5078 
  5079 * HOL/ex/Multiquote: example of multiple nested quotations and
  5080 anti-quotations -- basically a generalized version of de-Bruijn
  5081 representation; very useful in avoiding lifting of operations;
  5082 
  5083 * HOL/record: added general record equality rule to simpset; fixed
  5084 select-update simplification procedure to handle extended records as
  5085 well; admit "r" as field name;
  5086 
  5087 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5088 other numeric types and also as the identity of groups, rings, etc.;
  5089 
  5090 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5091 Types nat and int belong to this axclass;
  5092 
  5093 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5094    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5095    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5096   two terms #m*u and #n*u are replaced by #(m+n)*u
  5097     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5098   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5099     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5100 
  5101 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5102 powerful prover for predicate logic but knows nothing of clasets; see
  5103 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5104 
  5105 * HOL: new version of "case_tac" subsumes both boolean case split and
  5106 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5107 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5108 
  5109 * HOL: simplification no longer dives into case-expressions: only the
  5110 selector expression is simplified, but not the remaining arms; to
  5111 enable full simplification of case-expressions for datatype t, you may
  5112 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5113 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5114 
  5115 * HOL/recdef: the recursion equations generated by 'recdef' for
  5116 function 'f' are now called f.simps instead of f.rules; if all
  5117 termination conditions are proved automatically, these simplification
  5118 rules are added to the simpset, as in primrec; rules may be named
  5119 individually as well, resulting in a separate list of theorems for
  5120 each equation;
  5121 
  5122 * HOL/While is a new theory that provides a while-combinator. It
  5123 permits the definition of tail-recursive functions without the
  5124 provision of a termination measure. The latter is necessary once the
  5125 invariant proof rule for while is applied.
  5126 
  5127 * HOL: new (overloaded) notation for the set of elements below/above
  5128 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5129 
  5130 * HOL: theorems impI, allI, ballI bound as "strip";
  5131 
  5132 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5133 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5134 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5135 
  5136 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5137 
  5138 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5139 main HOL, but was unused);
  5140 
  5141 * HOL: fewer consts declared as global (e.g. have to refer to
  5142 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5143 
  5144 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5145 in case of overlap with user translations (e.g. judgements over
  5146 tuples); (note that the underlying logical represenation is still
  5147 bogus);
  5148 
  5149 
  5150 *** ZF ***
  5151 
  5152 * ZF: simplification automatically cancels common terms in arithmetic
  5153 expressions over nat and int;
  5154 
  5155 * ZF: new treatment of nat to minimize type-checking: all operators
  5156 coerce their operands to a natural number using the function natify,
  5157 making the algebraic laws unconditional;
  5158 
  5159 * ZF: as above, for int: operators coerce their operands to an integer
  5160 using the function intify;
  5161 
  5162 * ZF: the integer library now contains many of the usual laws for the
  5163 orderings, including $<=, and monotonicity laws for $+ and $*;
  5164 
  5165 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5166 simplification;
  5167 
  5168 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5169 to the simplifier and classical reasoner simultaneously;
  5170 
  5171 
  5172 *** General ***
  5173 
  5174 * Provers: blast_tac now handles actual object-logic rules as
  5175 assumptions; note that auto_tac uses blast_tac internally as well;
  5176 
  5177 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5178 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5179 
  5180 * Provers: delrules now handles destruct rules as well (no longer need
  5181 explicit make_elim);
  5182 
  5183 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5184   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5185 use instead the strong form,
  5186   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5187 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5188 from destruct-rules;
  5189 
  5190 * Provers: Simplifier.easy_setup provides a fast path to basic
  5191 Simplifier setup for new object-logics;
  5192 
  5193 * Pure: AST translation rules no longer require constant head on LHS;
  5194 
  5195 * Pure: improved name spaces: ambiguous output is qualified; support
  5196 for hiding of names;
  5197 
  5198 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5199 XSYMBOL_HOME; no longer need to do manual configuration in most
  5200 situations;
  5201 
  5202 * system: compression of ML heaps images may now be controlled via -c
  5203 option of isabelle and isatool usedir (currently only observed by
  5204 Poly/ML);
  5205 
  5206 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5207 useful for remote X11);
  5208 
  5209 * system: provide TAGS file for Isabelle sources;
  5210 
  5211 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5212 order;
  5213 
  5214 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5215 timing flag supersedes proof_timing and Toplevel.trace;
  5216 
  5217 * ML: new combinators |>> and |>>> for incremental transformations
  5218 with secondary results (e.g. certain theory extensions):
  5219 
  5220 * ML: PureThy.add_defs gets additional argument to indicate potential
  5221 overloading (usually false);
  5222 
  5223 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5224 results;
  5225 
  5226 
  5227 
  5228 New in Isabelle99 (October 1999)
  5229 --------------------------------
  5230 
  5231 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5232 
  5233 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5234 are no longer simplified.  (This allows the simplifier to unfold recursive
  5235 functional programs.)  To restore the old behaviour, declare
  5236 
  5237     Delcongs [if_weak_cong];
  5238 
  5239 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5240 complement;
  5241 
  5242 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5243 
  5244 * HOL/datatype: mutual_induct_tac no longer exists --
  5245   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5246 
  5247 * HOL/typedef: fixed type inference for representing set; type
  5248 arguments now have to occur explicitly on the rhs as type constraints;
  5249 
  5250 * ZF: The con_defs part of an inductive definition may no longer refer
  5251 to constants declared in the same theory;
  5252 
  5253 * HOL, ZF: the function mk_cases, generated by the inductive
  5254 definition package, has lost an argument.  To simplify its result, it
  5255 uses the default simpset instead of a supplied list of theorems.
  5256 
  5257 * HOL/List: the constructors of type list are now Nil and Cons;
  5258 
  5259 * Simplifier: the type of the infix ML functions
  5260         setSSolver addSSolver setSolver addSolver
  5261 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5262 for packaging solvers. A solver is created via
  5263         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5264 where the string argument is only a comment.
  5265 
  5266 
  5267 *** Proof tools ***
  5268 
  5269 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5270 decision procedure for linear arithmetic. Currently it is used for
  5271 types `nat', `int', and `real' in HOL (see below); it can, should and
  5272 will be instantiated for other types and logics as well.
  5273 
  5274 * The simplifier now accepts rewrite rules with flexible heads, eg
  5275      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5276   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5277   matching.
  5278 
  5279 
  5280 *** General ***
  5281 
  5282 * New Isabelle/Isar subsystem provides an alternative to traditional
  5283 tactical theorem proving; together with the ProofGeneral/isar user
  5284 interface it offers an interactive environment for developing human
  5285 readable proof documents (Isar == Intelligible semi-automated
  5286 reasoning); for further information see isatool doc isar-ref,
  5287 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5288 
  5289 * improved and simplified presentation of theories: better HTML markup
  5290 (including colors), graph views in several sizes; isatool usedir now
  5291 provides a proper interface for user theories (via -P option); actual
  5292 document preparation based on (PDF)LaTeX is available as well (for
  5293 new-style theories only); see isatool doc system for more information;
  5294 
  5295 * native support for Proof General, both for classic Isabelle and
  5296 Isabelle/Isar;
  5297 
  5298 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5299 using the graph browser tool;
  5300 
  5301 * Isabelle manuals now also available as PDF;
  5302 
  5303 * theory loader rewritten from scratch (may not be fully
  5304 bug-compatible); old loadpath variable has been replaced by show_path,
  5305 add_path, del_path, reset_path functions; new operations such as
  5306 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5307 isatool doc ref);
  5308 
  5309 * improved isatool install: option -k creates KDE application icon,
  5310 option -p DIR installs standalone binaries;
  5311 
  5312 * added ML_PLATFORM setting (useful for cross-platform installations);
  5313 more robust handling of platform specific ML images for SML/NJ;
  5314 
  5315 * the settings environment is now statically scoped, i.e. it is never
  5316 created again in sub-processes invoked from isabelle, isatool, or
  5317 Isabelle;
  5318 
  5319 * path element specification '~~' refers to '$ISABELLE_HOME';
  5320 
  5321 * in locales, the "assumes" and "defines" parts may be omitted if
  5322 empty;
  5323 
  5324 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5325 long arrows);
  5326 
  5327 * new print_mode "HTML";
  5328 
  5329 * new flag show_tags controls display of tags of theorems (which are
  5330 basically just comments that may be attached by some tools);
  5331 
  5332 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5333 mode and goal output format:
  5334 
  5335 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5336 244c244
  5337 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5338 ---
  5339 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5340 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5341 181c181
  5342 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5343 ---
  5344 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5345 
  5346 * function bind_thms stores lists of theorems (cf. bind_thm);
  5347 
  5348 * new shorthand tactics ftac, eatac, datac, fatac;
  5349 
  5350 * qed (and friends) now accept "" as result name; in that case the
  5351 theorem is not stored, but proper checks and presentation of the
  5352 result still apply;
  5353 
  5354 * theorem database now also indexes constants "Trueprop", "all",
  5355 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5356 
  5357 
  5358 *** HOL ***
  5359 
  5360 ** HOL arithmetic **
  5361 
  5362 * There are now decision procedures for linear arithmetic over nat and
  5363 int:
  5364 
  5365 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5366 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5367 are treated as atomic; subformulae not involving type `nat' or `int'
  5368 are ignored; quantified subformulae are ignored unless they are
  5369 positive universal or negative existential. The tactic has to be
  5370 invoked by hand and can be a little bit slow. In particular, the
  5371 running time is exponential in the number of occurrences of `min' and
  5372 `max', and `-' on `nat'.
  5373 
  5374 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5375 (negated) (in)equalities among the premises and the conclusion into
  5376 account (i.e. no compound formulae) and does not know about `min' and
  5377 `max', and `-' on `nat'. It is fast and is used automatically by the
  5378 simplifier.
  5379 
  5380 NB: At the moment, these decision procedures do not cope with mixed
  5381 nat/int formulae where the two parts interact, such as `m < n ==>
  5382 int(m) < int(n)'.
  5383 
  5384 * HOL/Numeral provides a generic theory of numerals (encoded
  5385 efficiently as bit strings); setup for types nat/int/real is in place;
  5386 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5387 int, existing theories and proof scripts may require a few additional
  5388 type constraints;
  5389 
  5390 * integer division and remainder can now be performed on constant
  5391 arguments;
  5392 
  5393 * many properties of integer multiplication, division and remainder
  5394 are now available;
  5395 
  5396 * An interface to the Stanford Validity Checker (SVC) is available through the
  5397 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5398 are proved automatically.  SVC must be installed separately, and its results
  5399 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5400 invocation of the underlying oracle).  For SVC see
  5401   http://verify.stanford.edu/SVC
  5402 
  5403 * IsaMakefile: the HOL-Real target now builds an actual image;
  5404 
  5405 
  5406 ** HOL misc **
  5407 
  5408 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5409 (in Isabelle/Isar) -- by Gertrud Bauer;
  5410 
  5411 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5412 analysis for assembly languages with subtypes;
  5413 
  5414 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5415 -- avoids syntactic ambiguities and treats state, transition, and
  5416 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5417 changed syntax and (many) tactics;
  5418 
  5419 * HOL/inductive: Now also handles more general introduction rules such
  5420   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5421   theorems are now maintained within the theory (maintained via the
  5422   "mono" attribute);
  5423 
  5424 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5425   (using function types) such as
  5426 
  5427   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5428 
  5429 * HOL/record: record_simproc (part of the default simpset) takes care
  5430 of selectors applied to updated records; record_split_tac is no longer
  5431 part of the default claset; update_defs may now be removed from the
  5432 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5433 
  5434   claset_ref () := claset() addSWrapper record_split_wrapper;
  5435   Delsimprocs [record_simproc]
  5436 
  5437 * HOL/typedef: fixed type inference for representing set; type
  5438 arguments now have to occur explicitly on the rhs as type constraints;
  5439 
  5440 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5441 names rather than an ML expression;
  5442 
  5443 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5444 supplied later.  Program schemes can be defined, such as
  5445     "While B C s = (if B s then While B C (C s) else s)"
  5446 where the well-founded relation can be chosen after B and C have been given.
  5447 
  5448 * HOL/List: the constructors of type list are now Nil and Cons;
  5449 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5450 course, ML tools referring to List.list.op # etc. have to be adapted;
  5451 
  5452 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5453 disabled by default; run isabelle with option -m HOL to get back to
  5454 the original Gordon/HOL-style output;
  5455 
  5456 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5457 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5458 
  5459 * HOL basic syntax simplified (more orthogonal): all variants of
  5460 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5461 Eps operator is provided as well: "SOME x. P[x]";
  5462 
  5463 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5464 
  5465 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5466 thus available for user theories;
  5467 
  5468 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5469 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5470 time;
  5471 
  5472 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5473 several times and then mp;
  5474 
  5475 
  5476 *** LK ***
  5477 
  5478 * the notation <<...>> is now available as a notation for sequences of
  5479 formulas;
  5480 
  5481 * the simplifier is now installed
  5482 
  5483 * the axiom system has been generalized (thanks to Soren Heilmann)
  5484 
  5485 * the classical reasoner now has a default rule database
  5486 
  5487 
  5488 *** ZF ***
  5489 
  5490 * new primrec section allows primitive recursive functions to be given
  5491 directly (as in HOL) over datatypes and the natural numbers;
  5492 
  5493 * new tactics induct_tac and exhaust_tac for induction (or case
  5494 analysis) over datatypes and the natural numbers;
  5495 
  5496 * the datatype declaration of type T now defines the recursor T_rec;
  5497 
  5498 * simplification automatically does freeness reasoning for datatype
  5499 constructors;
  5500 
  5501 * automatic type-inference, with AddTCs command to insert new
  5502 type-checking rules;
  5503 
  5504 * datatype introduction rules are now added as Safe Introduction rules
  5505 to the claset;
  5506 
  5507 * the syntax "if P then x else y" is now available in addition to
  5508 if(P,x,y);
  5509 
  5510 
  5511 *** Internal programming interfaces ***
  5512 
  5513 * tuned simplifier trace output; new flag debug_simp;
  5514 
  5515 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5516 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5517 
  5518 * AxClass.axclass_tac lost the theory argument;
  5519 
  5520 * tuned current_goals_markers semantics: begin / end goal avoids
  5521 printing empty lines;
  5522 
  5523 * removed prs and prs_fn hook, which was broken because it did not
  5524 include \n in its semantics, forcing writeln to add one
  5525 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5526 string -> unit if you really want to output text without newline;
  5527 
  5528 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5529 plain output, interface builders may have to enable 'isabelle_font'
  5530 mode to get Isabelle font glyphs as before;
  5531 
  5532 * refined token_translation interface; INCOMPATIBILITY: output length
  5533 now of type real instead of int;
  5534 
  5535 * theory loader actions may be traced via new ThyInfo.add_hook
  5536 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5537 your own database of information attached to *whole* theories -- as
  5538 opposed to intra-theory data slots offered via TheoryDataFun;
  5539 
  5540 * proper handling of dangling sort hypotheses (at last!);
  5541 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5542 extra sort hypotheses that can be witnessed from the type signature;
  5543 the force_strip_shyps flag is gone, any remaining shyps are simply
  5544 left in the theorem (with a warning issued by strip_shyps_warning);
  5545 
  5546 
  5547 
  5548 New in Isabelle98-1 (October 1998)
  5549 ----------------------------------
  5550 
  5551 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5552 
  5553 * several changes of automated proof tools;
  5554 
  5555 * HOL: major changes to the inductive and datatype packages, including
  5556 some minor incompatibilities of theory syntax;
  5557 
  5558 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5559 called `inj_on';
  5560 
  5561 * HOL: removed duplicate thms in Arith:
  5562   less_imp_add_less  should be replaced by  trans_less_add1
  5563   le_imp_add_le      should be replaced by  trans_le_add1
  5564 
  5565 * HOL: unary minus is now overloaded (new type constraints may be
  5566 required);
  5567 
  5568 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5569 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5570 now taken as an integer constant.
  5571 
  5572 * Pure: ML function 'theory_of' renamed to 'theory';
  5573 
  5574 
  5575 *** Proof tools ***
  5576 
  5577 * Simplifier:
  5578   1. Asm_full_simp_tac is now more aggressive.
  5579      1. It will sometimes reorient premises if that increases their power to
  5580         simplify.
  5581      2. It does no longer proceed strictly from left to right but may also
  5582         rotate premises to achieve further simplification.
  5583      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5584      old Asm_full_simp_tac in that it does not rotate premises.
  5585   2. The simplifier now knows a little bit about nat-arithmetic.
  5586 
  5587 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5588 allows for selected deletion of wrappers, by introduction of names for
  5589 wrapper functionals.  This implies that addbefore, addSbefore,
  5590 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5591 and that adding two tactics with the same name overwrites the first
  5592 one (emitting a warning).
  5593   type wrapper = (int -> tactic) -> (int -> tactic)
  5594   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5595   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5596   delWrapper, delSWrapper: claset *  string            -> claset
  5597   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5598 
  5599 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5600 semantics; addbefore now affects only the unsafe part of step_tac
  5601 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5602 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5603 by Force_tac;
  5604 
  5605 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5606 compWrapper; added safe wrapper (and access functions for it);
  5607 
  5608 * HOL/split_all_tac is now much faster and fails if there is nothing
  5609 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5610 and the names of the automatically generated variables have changed.
  5611 split_all_tac has moved within claset() from unsafe wrappers to safe
  5612 wrappers, which means that !!-bound variables are split much more
  5613 aggressively, and safe_tac and clarify_tac now split such variables.
  5614 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5615 Note: the same holds for record_split_tac, which does the job of
  5616 split_all_tac for record fields.
  5617 
  5618 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5619 permanently to the default simpset using Addsplits just like
  5620 Addsimps. They can be removed via Delsplits just like
  5621 Delsimps. Lower-case versions are also available.
  5622 
  5623 * HOL/Simplifier: The rule split_if is now part of the default
  5624 simpset. This means that the simplifier will eliminate all occurrences
  5625 of if-then-else in the conclusion of a goal. To prevent this, you can
  5626 either remove split_if completely from the default simpset by
  5627 `Delsplits [split_if]' or remove it in a specific call of the
  5628 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5629 other case splitting rules to/from the default simpset: every datatype
  5630 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5631 t is the name of the datatype).
  5632 
  5633 * Classical reasoner / Simplifier combination: new force_tac (and
  5634 derivatives Force_tac, force) combines rewriting and classical
  5635 reasoning (and whatever other tools) similarly to auto_tac, but is
  5636 aimed to solve the given subgoal completely.
  5637 
  5638 
  5639 *** General ***
  5640 
  5641 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5642 and `goalw': the theory is no longer needed as an explicit argument -
  5643 the current theory context is used; assumptions are no longer returned
  5644 at the ML-level unless one of them starts with ==> or !!; it is
  5645 recommended to convert to these new commands using isatool fixgoal
  5646 (backup your sources first!);
  5647 
  5648 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5649 the current theory context, and 'theory' to lookup stored theories;
  5650 
  5651 * new theory section 'locale' for declaring constants, assumptions and
  5652 definitions that have local scope;
  5653 
  5654 * new theory section 'nonterminals' for purely syntactic types;
  5655 
  5656 * new theory section 'setup' for generic ML setup functions
  5657 (e.g. package initialization);
  5658 
  5659 * the distribution now includes Isabelle icons: see
  5660 lib/logo/isabelle-{small,tiny}.xpm;
  5661 
  5662 * isatool install - install binaries with absolute references to
  5663 ISABELLE_HOME/bin;
  5664 
  5665 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5666 
  5667 * print mode 'emacs' reserved for Isamode;
  5668 
  5669 * support multiple print (ast) translations per constant name;
  5670 
  5671 * theorems involving oracles are now printed with a suffixed [!];
  5672 
  5673 
  5674 *** HOL ***
  5675 
  5676 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5677 
  5678 * HOL/inductive package reorganized and improved: now supports mutual
  5679 definitions such as
  5680 
  5681   inductive EVEN ODD
  5682     intrs
  5683       null "0 : EVEN"
  5684       oddI "n : EVEN ==> Suc n : ODD"
  5685       evenI "n : ODD ==> Suc n : EVEN"
  5686 
  5687 new theorem list "elims" contains an elimination rule for each of the
  5688 recursive sets; inductive definitions now handle disjunctive premises
  5689 correctly (also ZF);
  5690 
  5691 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5692 "mutual_induct" no longer exists - the induction rule is always
  5693 contained in "induct";
  5694 
  5695 
  5696 * HOL/datatype package re-implemented and greatly improved: now
  5697 supports mutually recursive datatypes such as
  5698 
  5699   datatype
  5700     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5701             | SUM ('a aexp) ('a aexp)
  5702             | DIFF ('a aexp) ('a aexp)
  5703             | NUM 'a
  5704   and
  5705     'a bexp = LESS ('a aexp) ('a aexp)
  5706             | AND ('a bexp) ('a bexp)
  5707             | OR ('a bexp) ('a bexp)
  5708 
  5709 as well as indirectly recursive datatypes such as
  5710 
  5711   datatype
  5712     ('a, 'b) term = Var 'a
  5713                   | App 'b ((('a, 'b) term) list)
  5714 
  5715 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5716 induction on mutually / indirectly recursive datatypes.
  5717 
  5718 Primrec equations are now stored in theory and can be accessed via
  5719 <function_name>.simps.
  5720 
  5721 INCOMPATIBILITIES:
  5722 
  5723   - Theories using datatypes must now have theory Datatype as an
  5724     ancestor.
  5725   - The specific <typename>.induct_tac no longer exists - use the
  5726     generic induct_tac instead.
  5727   - natE has been renamed to nat.exhaust - use exhaust_tac
  5728     instead of res_inst_tac ... natE. Note that the variable
  5729     names in nat.exhaust differ from the names in natE, this
  5730     may cause some "fragile" proofs to fail.
  5731   - The theorems split_<typename>_case and split_<typename>_case_asm
  5732     have been renamed to <typename>.split and <typename>.split_asm.
  5733   - Since default sorts of type variables are now handled correctly,
  5734     some datatype definitions may have to be annotated with explicit
  5735     sort constraints.
  5736   - Primrec definitions no longer require function name and type
  5737     of recursive argument.
  5738 
  5739 Consider using isatool fixdatatype to adapt your theories and proof
  5740 scripts to the new package (backup your sources first!).
  5741 
  5742 
  5743 * HOL/record package: considerably improved implementation; now
  5744 includes concrete syntax for record types, terms, updates; theorems
  5745 for surjective pairing and splitting !!-bound record variables; proof
  5746 support is as follows:
  5747 
  5748   1) standard conversions (selectors or updates applied to record
  5749 constructor terms) are part of the standard simpset;
  5750 
  5751   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5752 made part of standard simpset and claset via addIffs;
  5753 
  5754   3) a tactic for record field splitting (record_split_tac) is part of
  5755 the standard claset (addSWrapper);
  5756 
  5757 To get a better idea about these rules you may retrieve them via
  5758 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5759 the name of your record type.
  5760 
  5761 The split tactic 3) conceptually simplifies by the following rule:
  5762 
  5763   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5764 
  5765 Thus any record variable that is bound by meta-all will automatically
  5766 blow up into some record constructor term, consequently the
  5767 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5768 solve record problems automatically.
  5769 
  5770 
  5771 * reorganized the main HOL image: HOL/Integ and String loaded by
  5772 default; theory Main includes everything;
  5773 
  5774 * automatic simplification of integer sums and comparisons, using cancellation;
  5775 
  5776 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5777 
  5778 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5779 
  5780 * many new identities for unions, intersections, set difference, etc.;
  5781 
  5782 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5783 called split_if, split_split, split_sum_case and split_nat_case (to go
  5784 with add/delsplits);
  5785 
  5786 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5787 (?x::unit) = (); this is made part of the default simpset, which COULD
  5788 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5789 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5790 unit_abs_eta_conv is added in order to counter the effect of
  5791 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5792 %u.f();
  5793 
  5794 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5795 makes more sense);
  5796 
  5797 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5798   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5799   disjointness reasoning but breaking a few old proofs.
  5800 
  5801 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5802 to 'converse' from 'inverse' (for compatibility with ZF and some
  5803 literature);
  5804 
  5805 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5806 the well-founded relation;
  5807 
  5808 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5809     Compl A.  The "Compl" syntax remains available as input syntax for this
  5810     release ONLY.
  5811 
  5812 * HOL/Update: new theory of function updates:
  5813     f(a:=b) == %x. if x=a then b else f x
  5814 may also be iterated as in f(a:=b,c:=d,...);
  5815 
  5816 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5817 
  5818 * HOL/List:
  5819   - new function list_update written xs[i:=v] that updates the i-th
  5820     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5821   - new function `upt' written [i..j(] which generates the list
  5822     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5823     bound write [i..j], which is a shorthand for [i..j+1(].
  5824   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5825 
  5826 * HOL/Arith:
  5827   - removed 'pred' (predecessor) function;
  5828   - generalized some theorems about n-1;
  5829   - many new laws about "div" and "mod";
  5830   - new laws about greatest common divisors (see theory ex/Primes);
  5831 
  5832 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5833 instead of "inverse";
  5834 
  5835 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5836   of the multiset ordering;
  5837 
  5838 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5839   (not included by default);
  5840 
  5841 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5842 
  5843 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5844   programs, i.e. different program variables may have different types.
  5845 
  5846 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5847   [previously, this check worked only if the rewrite rule was unconditional]
  5848   Now rew can involve either definitions or equalities (either == or =).
  5849 
  5850 
  5851 *** ZF ***
  5852 
  5853 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5854   only the theorems proved on ZF.ML;
  5855 
  5856 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5857   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5858   disjointness reasoning but breaking a few old proofs.
  5859 
  5860 * ZF/Update: new theory of function updates
  5861     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5862   may also be iterated as in f(a:=b,c:=d,...);
  5863 
  5864 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5865 
  5866 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5867   [previously, this check worked only if the rewrite rule was unconditional]
  5868   Now rew can involve either definitions or equalities (either == or =).
  5869 
  5870 * case_tac provided for compatibility with HOL
  5871     (like the old excluded_middle_tac, but with subgoals swapped)
  5872 
  5873 
  5874 *** Internal programming interfaces ***
  5875 
  5876 * Pure: several new basic modules made available for general use, see
  5877 also src/Pure/README;
  5878 
  5879 * improved the theory data mechanism to support encapsulation (data
  5880 kind name replaced by private Object.kind, acting as authorization
  5881 key); new type-safe user interface via functor TheoryDataFun; generic
  5882 print_data function becomes basically useless;
  5883 
  5884 * removed global_names compatibility flag -- all theory declarations
  5885 are qualified by default;
  5886 
  5887 * module Pure/Syntax now offers quote / antiquote translation
  5888 functions (useful for Hoare logic etc. with implicit dependencies);
  5889 see HOL/ex/Antiquote for an example use;
  5890 
  5891 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5892 cterm -> thm;
  5893 
  5894 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5895 subgoal;
  5896 
  5897 * Display.print_goals function moved to Locale.print_goals;
  5898 
  5899 * standard print function for goals supports current_goals_markers
  5900 variable for marking begin of proof, end of proof, start of goal; the
  5901 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5902 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5903 for example;
  5904 
  5905 
  5906 
  5907 New in Isabelle98 (January 1998)
  5908 --------------------------------
  5909 
  5910 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5911 
  5912 * changed lexical syntax of terms / types: dots made part of long
  5913 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5914 
  5915 * simpset (and claset) reference variable replaced by functions
  5916 simpset / simpset_ref;
  5917 
  5918 * no longer supports theory aliases (via merge) and non-trivial
  5919 implicit merge of thms' signatures;
  5920 
  5921 * most internal names of constants changed due to qualified names;
  5922 
  5923 * changed Pure/Sequence interface (see Pure/seq.ML);
  5924 
  5925 
  5926 *** General Changes ***
  5927 
  5928 * hierachically structured name spaces (for consts, types, axms, thms
  5929 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5930 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5931 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5932 long_names for fully qualified output names; NOTE: ML programs
  5933 (special tactics, packages etc.) referring to internal names may have
  5934 to be adapted to cope with fully qualified names; in case of severe
  5935 backward campatibility problems try setting 'global_names' at compile
  5936 time to have enrything declared within a flat name space; one may also
  5937 fine tune name declarations in theories via the 'global' and 'local'
  5938 section;
  5939 
  5940 * reimplemented the implicit simpset and claset using the new anytype
  5941 data filed in signatures; references simpset:simpset ref etc. are
  5942 replaced by functions simpset:unit->simpset and
  5943 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5944 to patch your ML files accordingly;
  5945 
  5946 * HTML output now includes theory graph data for display with Java
  5947 applet or isatool browser; data generated automatically via isatool
  5948 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5949 
  5950 * defs may now be conditional; improved rewrite_goals_tac to handle
  5951 conditional equations;
  5952 
  5953 * defs now admits additional type arguments, using TYPE('a) syntax;
  5954 
  5955 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5956 creates a new theory node; implicit merge of thms' signatures is
  5957 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5958 transfer:theory->thm->thm in (rare) cases;
  5959 
  5960 * improved handling of draft signatures / theories; draft thms (and
  5961 ctyps, cterms) are automatically promoted to real ones;
  5962 
  5963 * slightly changed interfaces for oracles: admit many per theory, named
  5964 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5965 
  5966 * print_goals: optional output of const types (set show_consts and
  5967 show_types);
  5968 
  5969 * improved output of warnings (###) and errors (***);
  5970 
  5971 * subgoal_tac displays a warning if the new subgoal has type variables;
  5972 
  5973 * removed old README and Makefiles;
  5974 
  5975 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5976 
  5977 * removed obsolete init_pps and init_database;
  5978 
  5979 * deleted the obsolete tactical STATE, which was declared by
  5980     fun STATE tacfun st = tacfun st st;
  5981 
  5982 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5983 (which abbreviates $HOME);
  5984 
  5985 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5986 use isatool fixseq to adapt your ML programs (this works for fully
  5987 qualified references to the Sequence structure only!);
  5988 
  5989 * use_thy no longer requires writable current directory; it always
  5990 reloads .ML *and* .thy file, if either one is out of date;
  5991 
  5992 
  5993 *** Classical Reasoner ***
  5994 
  5995 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5996 tactics that use classical reasoning to simplify a subgoal without
  5997 splitting it into several subgoals;
  5998 
  5999 * Safe_tac: like safe_tac but uses the default claset;
  6000 
  6001 
  6002 *** Simplifier ***
  6003 
  6004 * added simplification meta rules:
  6005     (asm_)(full_)simplify: simpset -> thm -> thm;
  6006 
  6007 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6008 logics (again);
  6009 
  6010 * added prems argument to simplification procedures;
  6011 
  6012 * HOL, FOL, ZF: added infix function `addsplits':
  6013   instead of `<simpset> setloop (split_tac <thms>)'
  6014   you can simply write `<simpset> addsplits <thms>'
  6015 
  6016 
  6017 *** Syntax ***
  6018 
  6019 * TYPE('a) syntax for type reflection terms;
  6020 
  6021 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6022 
  6023 * pretty printer: changed order of mixfix annotation preference (again!);
  6024 
  6025 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6026 
  6027 
  6028 *** HOL ***
  6029 
  6030 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6031   with `addloop' of the simplifier to faciliate case splitting in premises.
  6032 
  6033 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6034 
  6035 * HOL/Auth: new protocol proofs including some for the Internet
  6036   protocol TLS;
  6037 
  6038 * HOL/Map: new theory of `maps' a la VDM;
  6039 
  6040 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6041 cancelling out common nat summands from =, <, <= (in)equalities, or
  6042 differences; simplification procedures nat_cancel_factor for
  6043 cancelling common factor from =, <, <= (in)equalities over natural
  6044 sums; nat_cancel contains both kinds of procedures, it is installed by
  6045 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6046 
  6047 * HOL/simplifier: terms of the form
  6048   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6049   are rewritten to
  6050   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6051   and those of the form
  6052   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6053   are rewritten to
  6054   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6055 
  6056 * HOL/datatype
  6057   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6058 
  6059   P(t_case f1 ... fn x) =
  6060      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6061         ...
  6062        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6063      )
  6064 
  6065   and a theorem `split_t_case_asm' of the form
  6066 
  6067   P(t_case f1 ... fn x) =
  6068     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6069         ...
  6070        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6071      )
  6072   which can be added to a simpset via `addsplits'. The existing theorems
  6073   expand_list_case and expand_option_case have been renamed to
  6074   split_list_case and split_option_case.
  6075 
  6076 * HOL/Arithmetic:
  6077   - `pred n' is automatically converted to `n-1'.
  6078     Users are strongly encouraged not to use `pred' any longer,
  6079     because it will disappear altogether at some point.
  6080   - Users are strongly encouraged to write "0 < n" rather than
  6081     "n ~= 0". Theorems and proof tools have been modified towards this
  6082     `standard'.
  6083 
  6084 * HOL/Lists:
  6085   the function "set_of_list" has been renamed "set" (and its theorems too);
  6086   the function "nth" now takes its arguments in the reverse order and
  6087   has acquired the infix notation "!" as in "xs!n".
  6088 
  6089 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6090 
  6091 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6092   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6093 
  6094 * HOL/record: extensible records with schematic structural subtyping
  6095 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6096 still lacks various theorems and concrete record syntax;
  6097 
  6098 
  6099 *** HOLCF ***
  6100 
  6101 * removed "axioms" and "generated by" sections;
  6102 
  6103 * replaced "ops" section by extended "consts" section, which is capable of
  6104   handling the continuous function space "->" directly;
  6105 
  6106 * domain package:
  6107   . proves theorems immediately and stores them in the theory,
  6108   . creates hierachical name space,
  6109   . now uses normal mixfix annotations (instead of cinfix...),
  6110   . minor changes to some names and values (for consistency),
  6111   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6112   . separator between mutual domain defs: changed "," to "and",
  6113   . improved handling of sort constraints;  now they have to
  6114     appear on the left-hand side of the equations only;
  6115 
  6116 * fixed LAM <x,y,zs>.b syntax;
  6117 
  6118 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6119 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6120 
  6121 
  6122 *** FOL and ZF ***
  6123 
  6124 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6125   with `addloop' of the simplifier to faciliate case splitting in premises.
  6126 
  6127 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6128 in HOL, they strip ALL and --> from proved theorems;
  6129 
  6130 
  6131 
  6132 New in Isabelle94-8 (May 1997)
  6133 ------------------------------
  6134 
  6135 *** General Changes ***
  6136 
  6137 * new utilities to build / run / maintain Isabelle etc. (in parts
  6138 still somewhat experimental); old Makefiles etc. still functional;
  6139 
  6140 * new 'Isabelle System Manual';
  6141 
  6142 * INSTALL text, together with ./configure and ./build scripts;
  6143 
  6144 * reimplemented type inference for greater efficiency, better error
  6145 messages and clean internal interface;
  6146 
  6147 * prlim command for dealing with lots of subgoals (an easier way of
  6148 setting goals_limit);
  6149 
  6150 
  6151 *** Syntax ***
  6152 
  6153 * supports alternative (named) syntax tables (parser and pretty
  6154 printer); internal interface is provided by add_modesyntax(_i);
  6155 
  6156 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6157 be used in conjunction with the Isabelle symbol font; uses the
  6158 "symbols" syntax table;
  6159 
  6160 * added token_translation interface (may translate name tokens in
  6161 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6162 the current print_mode); IMPORTANT: user print translation functions
  6163 are responsible for marking newly introduced bounds
  6164 (Syntax.mark_boundT);
  6165 
  6166 * token translations for modes "xterm" and "xterm_color" that display
  6167 names in bold, underline etc. or colors (which requires a color
  6168 version of xterm);
  6169 
  6170 * infixes may now be declared with names independent of their syntax;
  6171 
  6172 * added typed_print_translation (like print_translation, but may
  6173 access type of constant);
  6174 
  6175 
  6176 *** Classical Reasoner ***
  6177 
  6178 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6179 some limitations.  Blast_tac...
  6180   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6181   + ignores elimination rules that don't have the correct format
  6182         (the conclusion MUST be a formula variable)
  6183   + ignores types, which can make HOL proofs fail
  6184   + rules must not require higher-order unification, e.g. apply_type in ZF
  6185     [message "Function Var's argument not a bound variable" relates to this]
  6186   + its proof strategy is more general but can actually be slower
  6187 
  6188 * substitution with equality assumptions no longer permutes other
  6189 assumptions;
  6190 
  6191 * minor changes in semantics of addafter (now called addaltern); renamed
  6192 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6193 (and access functions for it);
  6194 
  6195 * improved combination of classical reasoner and simplifier:
  6196   + functions for handling clasimpsets
  6197   + improvement of addss: now the simplifier is called _after_ the
  6198     safe steps.
  6199   + safe variant of addss called addSss: uses safe simplifications
  6200     _during_ the safe steps. It is more complete as it allows multiple
  6201     instantiations of unknowns (e.g. with slow_tac).
  6202 
  6203 *** Simplifier ***
  6204 
  6205 * added interface for simplification procedures (functions that
  6206 produce *proven* rewrite rules on the fly, depending on current
  6207 redex);
  6208 
  6209 * ordering on terms as parameter (used for ordered rewriting);
  6210 
  6211 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6212 
  6213 * the solver is now split into a safe and an unsafe part.
  6214 This should be invisible for the normal user, except that the
  6215 functions setsolver and addsolver have been renamed to setSolver and
  6216 addSolver; added safe_asm_full_simp_tac;
  6217 
  6218 
  6219 *** HOL ***
  6220 
  6221 * a generic induction tactic `induct_tac' which works for all datatypes and
  6222 also for type `nat';
  6223 
  6224 * a generic case distinction tactic `exhaust_tac' which works for all
  6225 datatypes and also for type `nat';
  6226 
  6227 * each datatype comes with a function `size';
  6228 
  6229 * patterns in case expressions allow tuple patterns as arguments to
  6230 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6231 
  6232 * primrec now also works with type nat;
  6233 
  6234 * recdef: a new declaration form, allows general recursive functions to be
  6235 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6236 
  6237 * the constant for negation has been renamed from "not" to "Not" to
  6238 harmonize with FOL, ZF, LK, etc.;
  6239 
  6240 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6241 infinite lists;
  6242 
  6243 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6244 
  6245 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6246 problems in commutative rings, using axiomatic type classes for + and *;
  6247 
  6248 * more examples in HOL/MiniML and HOL/Auth;
  6249 
  6250 * more default rewrite rules for quantifiers, union/intersection;
  6251 
  6252 * a new constant `arbitrary == @x.False';
  6253 
  6254 * HOLCF/IOA replaces old HOL/IOA;
  6255 
  6256 * HOLCF changes: derived all rules and arities
  6257   + axiomatic type classes instead of classes
  6258   + typedef instead of faking type definitions
  6259   + eliminated the internal constan