NEWS
author haftmann
Mon Jul 27 09:01:13 2009 +0200 (2009-07-27)
changeset 32217 420108dd7dfe
parent 32216 2f3d65d15149
child 32235 8f9b8d14fc9f
permissions -rw-r--r--
NEWS
     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 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   - class "complete_lattice" moved to separate theory "complete_lattice";
    44     corresponding constants renamed:
    45     
    46     Set.Inf ~>      Complete_Lattice.Inf
    47     Set.Sup ~>      Complete_Lattice.Sup
    48     Set.INFI ~>     Complete_Lattice.INFI
    49     Set.SUPR ~>     Complete_Lattice.SUPR
    50     Set.Inter ~>    Complete_Lattice.Inter
    51     Set.Union ~>    Complete_Lattice.Union
    52     Set.INTER ~>    Complete_Lattice.INTER
    53     Set.UNION ~>    Complete_Lattice.UNION
    54 
    55   INCOMPATIBILITY.
    56 
    57 * Class semiring_div requires superclass no_zero_divisors and proof of
    58 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    59 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    60 generalized to class semiring_div, subsuming former theorems
    61 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    62 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    63 INCOMPATIBILITY.
    64 
    65 * Power operations on relations and functions are now one dedicate
    66 constant compow with infix syntax "^^".  Power operations on
    67 multiplicative monoids retains syntax "^" and is now defined generic
    68 in class power.  INCOMPATIBILITY.
    69 
    70 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    71 infinite sets. It is shown that they form a complete lattice.
    72 
    73 * ML antiquotation @{code_datatype} inserts definition of a datatype
    74 generated by the code generator; see Predicate.thy for an example.
    75 
    76 * New method "linarith" invokes existing linear arithmetic decision
    77 procedure only.
    78 
    79 * Implementation of quickcheck using generic code generator; default
    80 generators are provided for all suitable HOL types, records and
    81 datatypes.
    82 
    83 * Constants Set.Pow and Set.image now with authentic syntax;
    84 object-logic definitions Set.Pow_def and Set.image_def.
    85 INCOMPATIBILITY.
    86 
    87 * Renamed theorems:
    88 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    89 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    90 Suc_plus1 -> Suc_eq_plus1
    91 
    92 * New sledgehammer option "Full Types" in Proof General settings menu.
    93 Causes full type information to be output to the ATPs.  This slows
    94 ATPs down considerably but eliminates a source of unsound "proofs"
    95 that fail later.
    96 
    97 * Discontinued ancient tradition to suffix certain ML module names
    98 with "_package", e.g.:
    99 
   100     DatatypePackage ~> Datatype
   101     InductivePackage ~> Inductive
   102 
   103     etc.
   104 
   105 INCOMPATIBILITY.
   106 
   107 * NewNumberTheory: Jeremy Avigad's new version of part of
   108 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
   109 
   110 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
   111 
   112 * Abbreviation "arbitrary" of "undefined" has disappeared; use
   113 "undefined" directly.  INCOMPATIBILITY.
   114 
   115 * New evaluator "approximate" approximates an real valued term using
   116 the same method as the approximation method.
   117 
   118 * Method "approximate" supports now arithmetic expressions as
   119 boundaries of intervals and implements interval splitting and Taylor
   120 series expansion.
   121 
   122 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   123 the theorems in DERIV_intros assumes composition with an additional
   124 function and matches a variable to the derivative, which has to be
   125 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   126 the derivative of most elementary terms.
   127 
   128 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   129 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   130 
   131 
   132 *** ML ***
   133 
   134 * Tactical FOCUS is similar to SUBPROOF, but allows the body tactic to
   135 introduce new subgoals and schematic variables.  FOCUS_PARAMS is
   136 similar, but focuses on the parameter prefix only, leaving subgoal
   137 premises unchanged.
   138 
   139 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   140 functors have their own ML name space there is no point to mark them
   141 separately.)  Minor INCOMPATIBILITY.
   142 
   143 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   144 
   145 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   146 cominators for "args".  INCOMPATIBILITY, need to use simplified
   147 Attrib/Method.setup introduced in Isabelle2009.
   148 
   149 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   150 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   151 last resort.  INCOMPATIBILITY.
   152 
   153 * Display.pretty_thm now requires a proper context (cf. former
   154 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   155 or even Display.pretty_thm_without_context as last resort.
   156 INCOMPATIBILITY.
   157 
   158 
   159 *** System ***
   160 
   161 * Discontinued support for Poly/ML 4.x versions.
   162 
   163 * Removed "compress" option from isabelle-process and isabelle usedir;
   164 this is always enabled.
   165 
   166 * More fine-grained control of proof parallelism, cf.
   167 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   168 
   169 
   170 
   171 New in Isabelle2009 (April 2009)
   172 --------------------------------
   173 
   174 *** General ***
   175 
   176 * Simplified main Isabelle executables, with less surprises on
   177 case-insensitive file-systems (such as Mac OS).
   178 
   179   - The main Isabelle tool wrapper is now called "isabelle" instead of
   180     "isatool."
   181 
   182   - The former "isabelle" alias for "isabelle-process" has been
   183     removed (should rarely occur to regular users).
   184 
   185   - The former "isabelle-interface" and its alias "Isabelle" have been
   186     removed (interfaces are now regular Isabelle tools).
   187 
   188 Within scripts and make files, the Isabelle environment variables
   189 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   190 respectively.  (The latter are still available as legacy feature.)
   191 
   192 The old isabelle-interface wrapper could react in confusing ways if
   193 the interface was uninstalled or changed otherwise.  Individual
   194 interface tool configuration is now more explicit, see also the
   195 Isabelle system manual.  In particular, Proof General is now available
   196 via "isabelle emacs".
   197 
   198 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   199 purge installed copies of Isabelle executables and re-run "isabelle
   200 install -p ...", or use symlinks.
   201 
   202 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   203 old ~/isabelle, which was slightly non-standard and apt to cause
   204 surprises on case-insensitive file-systems (such as Mac OS).
   205 
   206 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   207 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   208 care is required when using older releases of Isabelle.  Note that
   209 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   210 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   211 
   212 * Proofs of fully specified statements are run in parallel on
   213 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   214 a regular 4-core machine, if the initial heap space is made reasonably
   215 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   216 
   217 * The main reference manuals ("isar-ref", "implementation", and
   218 "system") have been updated and extended.  Formally checked references
   219 as hyperlinks are now available uniformly.
   220 
   221 
   222 *** Pure ***
   223 
   224 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   225 respects.  The most important changes are listed below.  See the
   226 Tutorial on Locales ("locales" manual) for details.
   227 
   228 - In locale expressions, instantiation replaces renaming.  Parameters
   229 must be declared in a for clause.  To aid compatibility with previous
   230 parameter inheritance, in locale declarations, parameters that are not
   231 'touched' (instantiation position "_" or omitted) are implicitly added
   232 with their syntax at the beginning of the for clause.
   233 
   234 - Syntax from abbreviations and definitions in locales is available in
   235 locale expressions and context elements.  The latter is particularly
   236 useful in locale declarations.
   237 
   238 - More flexible mechanisms to qualify names generated by locale
   239 expressions.  Qualifiers (prefixes) may be specified in locale
   240 expressions, and can be marked as mandatory (syntax: "name!:") or
   241 optional (syntax "name?:").  The default depends for plain "name:"
   242 depends on the situation where a locale expression is used: in
   243 commands 'locale' and 'sublocale' prefixes are optional, in
   244 'interpretation' and 'interpret' prefixes are mandatory.  The old
   245 implicit qualifiers derived from the parameter names of a locale are
   246 no longer generated.
   247 
   248 - Command "sublocale l < e" replaces "interpretation l < e".  The
   249 instantiation clause in "interpretation" and "interpret" (square
   250 brackets) is no longer available.  Use locale expressions.
   251 
   252 - When converting proof scripts, mandatory qualifiers in
   253 'interpretation' and 'interpret' should be retained by default, even
   254 if this is an INCOMPATIBILITY compared to former behavior.  In the
   255 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   256 in locale expressions range over a single locale instance only.
   257 
   258 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   259 In existing theorem specifications replace the includes element by the
   260 respective context elements of the included locale, omitting those
   261 that are already present in the theorem specification.  Multiple
   262 assume elements of a locale should be replaced by a single one
   263 involving the locale predicate.  In the proof body, declarations (most
   264 notably theorems) may be regained by interpreting the respective
   265 locales in the proof context as required (command "interpret").
   266 
   267 If using "includes" in replacement of a target solely because the
   268 parameter types in the theorem are not as general as in the target,
   269 consider declaring a new locale with additional type constraints on
   270 the parameters (context element "constrains").
   271 
   272 - Discontinued "locale (open)".  INCOMPATIBILITY.
   273 
   274 - Locale interpretation commands no longer attempt to simplify goal.
   275 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   276 methods intro_locales and unfold_locales to clarify.
   277 
   278 - Locale interpretation commands no longer accept interpretation
   279 attributes.  INCOMPATIBILITY.
   280 
   281 * Class declaration: so-called "base sort" must not be given in import
   282 list any longer, but is inferred from the specification.  Particularly
   283 in HOL, write
   284 
   285     class foo = ...
   286 
   287 instead of
   288 
   289     class foo = type + ...
   290 
   291 * Class target: global versions of theorems stemming do not carry a
   292 parameter prefix any longer.  INCOMPATIBILITY.
   293 
   294 * Class 'instance' command no longer accepts attached definitions.
   295 INCOMPATIBILITY, use proper 'instantiation' target instead.
   296 
   297 * Recovered hiding of consts, which was accidentally broken in
   298 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   299 makes c inaccessible; consider using ``hide (open) const c'' instead.
   300 
   301 * Slightly more coherent Pure syntax, with updated documentation in
   302 isar-ref manual.  Removed locales meta_term_syntax and
   303 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   304 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   305 directly in regular applications.
   306 
   307 * There is a new syntactic category "float_const" for signed decimal
   308 fractions (e.g. 123.45 or -123.45).
   309 
   310 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   311 interface with 'setup' command instead.
   312 
   313 * Command 'local_setup' is similar to 'setup', but operates on a local
   314 theory context.
   315 
   316 * The 'axiomatization' command now only works within a global theory
   317 context.  INCOMPATIBILITY.
   318 
   319 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   320 hypotheses.  Sorts required in the course of reasoning need to be
   321 covered by the constraints in the initial statement, completed by the
   322 type instance information of the background theory.  Non-trivial sort
   323 hypotheses, which rarely occur in practice, may be specified via
   324 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   325 
   326   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   327 
   328 The result contains an implicit sort hypotheses as before --
   329 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   330 normalization.
   331 
   332 * Generalized Isar history, with support for linear undo, direct state
   333 addressing etc.
   334 
   335 * Changed defaults for unify configuration options:
   336 
   337   unify_trace_bound = 50 (formerly 25)
   338   unify_search_bound = 60 (formerly 30)
   339 
   340 * Different bookkeeping for code equations (INCOMPATIBILITY):
   341 
   342   a) On theory merge, the last set of code equations for a particular
   343      constant is taken (in accordance with the policy applied by other
   344      parts of the code generator framework).
   345 
   346   b) Code equations stemming from explicit declarations (e.g. code
   347      attribute) gain priority over default code equations stemming
   348      from definition, primrec, fun etc.
   349 
   350 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   351 
   352 * Unified theorem tables for both code generators.  Thus [code
   353 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   354 
   355 * Command 'find_consts' searches for constants based on type and name
   356 patterns, e.g.
   357 
   358     find_consts "_ => bool"
   359 
   360 By default, matching is against subtypes, but it may be restricted to
   361 the whole type.  Searching by name is possible.  Multiple queries are
   362 conjunctive and queries may be negated by prefixing them with a
   363 hyphen:
   364 
   365     find_consts strict: "_ => bool" name: "Int" -"int => int"
   366 
   367 * New 'find_theorems' criterion "solves" matches theorems that
   368 directly solve the current goal (modulo higher-order unification).
   369 
   370 * Auto solve feature for main theorem statements: whenever a new goal
   371 is stated, "find_theorems solves" is called; any theorems that could
   372 solve the lemma directly are listed as part of the goal state.
   373 Cf. associated options in Proof General Isabelle settings menu,
   374 enabled by default, with reasonable timeout for pathological cases of
   375 higher-order unification.
   376 
   377 
   378 *** Document preparation ***
   379 
   380 * Antiquotation @{lemma} now imitates a regular terminal proof,
   381 demanding keyword 'by' and supporting the full method expression
   382 syntax just like the Isar command 'by'.
   383 
   384 
   385 *** HOL ***
   386 
   387 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   388 points Main and Complex_Main remain as before.
   389 
   390 * Logic image HOL-Plain provides a minimal HOL with the most important
   391 tools available (inductive, datatype, primrec, ...).  This facilitates
   392 experimentation and tool development.  Note that user applications
   393 (and library theories) should never refer to anything below theory
   394 Main, as before.
   395 
   396 * Logic image HOL-Main stops at theory Main, and thus facilitates
   397 experimentation due to shorter build times.
   398 
   399 * Logic image HOL-NSA contains theories of nonstandard analysis which
   400 were previously part of former HOL-Complex.  Entry point Hyperreal
   401 remains valid, but theories formerly using Complex_Main should now use
   402 new entry point Hypercomplex.
   403 
   404 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   405 Posix processes.  Avoids potentially expensive forking of the ML
   406 process.  New thread-based implementation also works on non-Unix
   407 platforms (Cygwin).  Provers are no longer hardwired, but defined
   408 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   409 commands are covered in the isar-ref manual.
   410 
   411 * Wrapper scripts for remote SystemOnTPTP service allows to use
   412 sledgehammer without local ATP installation (Vampire etc.). Other
   413 provers may be included via suitable ML wrappers, see also
   414 src/HOL/ATP_Linkup.thy.
   415 
   416 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   417 menu.
   418 
   419 * The metis method no longer fails because the theorem is too trivial
   420 (contains the empty clause).
   421 
   422 * The metis method now fails in the usual manner, rather than raising
   423 an exception, if it determines that it cannot prove the theorem.
   424 
   425 * Method "coherent" implements a prover for coherent logic (see also
   426 src/Tools/coherent.ML).
   427 
   428 * Constants "undefined" and "default" replace "arbitrary".  Usually
   429 "undefined" is the right choice to replace "arbitrary", though
   430 logically there is no difference.  INCOMPATIBILITY.
   431 
   432 * Command "value" now integrates different evaluation mechanisms.  The
   433 result of the first successful evaluation mechanism is printed.  In
   434 square brackets a particular named evaluation mechanisms may be
   435 specified (currently, [SML], [code] or [nbe]).  See further
   436 src/HOL/ex/Eval_Examples.thy.
   437 
   438 * Normalization by evaluation now allows non-leftlinear equations.
   439 Declare with attribute [code nbe].
   440 
   441 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   442 as the structured Isar versions "cases" and "induct", cf. the
   443 corresponding "cases" and "induct" attributes.  Mutual induction rules
   444 are now presented as a list of individual projections
   445 (e.g. foo_bar.inducts for types foo and bar); the old format with
   446 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   447 rare situations a different rule is selected --- notably nested tuple
   448 elimination instead of former prod.exhaust: use explicit (case_tac t
   449 rule: prod.exhaust) here.
   450 
   451 * Attributes "cases", "induct", "coinduct" support "del" option.
   452 
   453 * Removed fact "case_split_thm", which duplicates "case_split".
   454 
   455 * The option datatype has been moved to a new theory Option.  Renamed
   456 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   457 
   458 * New predicate "strict_mono" classifies strict functions on partial
   459 orders.  With strict functions on linear orders, reasoning about
   460 (in)equalities is facilitated by theorems "strict_mono_eq",
   461 "strict_mono_less_eq" and "strict_mono_less".
   462 
   463 * Some set operations are now proper qualified constants with
   464 authentic syntax.  INCOMPATIBILITY:
   465 
   466     op Int ~>   Set.Int
   467     op Un ~>    Set.Un
   468     INTER ~>    Set.INTER
   469     UNION ~>    Set.UNION
   470     Inter ~>    Set.Inter
   471     Union ~>    Set.Union
   472     {} ~>       Set.empty
   473     UNIV ~>     Set.UNIV
   474 
   475 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   476 theory Set.
   477 
   478 * Auxiliary class "itself" has disappeared -- classes without any
   479 parameter are treated as expected by the 'class' command.
   480 
   481 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   482 
   483 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   484 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   485 
   486 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   487 method "approximation".  It proves formulas on real values by using
   488 interval arithmetic.  In the formulas are also the transcendental
   489 functions sin, cos, tan, atan, ln, exp and the constant pi are
   490 allowed. For examples see
   491 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   492 
   493 * Theory "Reflection" now resides in HOL/Library.
   494 
   495 * Entry point to Word library now simply named "Word".
   496 INCOMPATIBILITY.
   497 
   498 * Made source layout more coherent with logical distribution
   499 structure:
   500 
   501     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   502     src/HOL/Library/Code_Message.thy ~> src/HOL/
   503     src/HOL/Library/GCD.thy ~> src/HOL/
   504     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   505     src/HOL/Library/Parity.thy ~> src/HOL/
   506     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   507     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   508     src/HOL/Real/Lubs.thy ~> src/HOL/
   509     src/HOL/Real/PReal.thy ~> src/HOL/
   510     src/HOL/Real/Rational.thy ~> src/HOL/
   511     src/HOL/Real/RComplete.thy ~> src/HOL/
   512     src/HOL/Real/RealDef.thy ~> src/HOL/
   513     src/HOL/Real/RealPow.thy ~> src/HOL/
   514     src/HOL/Real/Real.thy ~> src/HOL/
   515     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   516     src/HOL/Complex/Complex.thy ~> src/HOL/
   517     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   518     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   519     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   520     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   521     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   522     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   523     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   524     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   525     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   526     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   527     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   528     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   529     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   530     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   531     src/HOL/Real/Float ~> src/HOL/Library/
   532     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   533     src/HOL/Real/RealVector.thy ~> src/HOL/
   534 
   535     src/HOL/arith_data.ML ~> src/HOL/Tools
   536     src/HOL/hologic.ML ~> src/HOL/Tools
   537     src/HOL/simpdata.ML ~> src/HOL/Tools
   538     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   539     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   540     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   541     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   542     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   543     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   544     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   545 
   546     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   547     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   548     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   549     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   550     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   551     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   552 
   553 * If methods "eval" and "evaluation" encounter a structured proof
   554 state with !!/==>, only the conclusion is evaluated to True (if
   555 possible), avoiding strange error messages.
   556 
   557 * Method "sizechange" automates termination proofs using (a
   558 modification of) the size-change principle.  Requires SAT solver.  See
   559 src/HOL/ex/Termination.thy for examples.
   560 
   561 * Simplifier: simproc for let expressions now unfolds if bound
   562 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   563 
   564 * Method "arith": Linear arithmetic now ignores all inequalities when
   565 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   566 
   567 * New attribute "arith" for facts that should always be used
   568 automatically by arithmetic. It is intended to be used locally in
   569 proofs, e.g.
   570 
   571   assumes [arith]: "x > 0"
   572 
   573 Global usage is discouraged because of possible performance impact.
   574 
   575 * New classes "top" and "bot" with corresponding operations "top" and
   576 "bot" in theory Orderings; instantiation of class "complete_lattice"
   577 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   578 
   579 * Changed definition lemma "less_fun_def" in order to provide an
   580 instance for preorders on functions; use lemma "less_le" instead.
   581 INCOMPATIBILITY.
   582 
   583 * Theory Orderings: class "wellorder" moved here, with explicit
   584 induction rule "less_induct" as assumption.  For instantiation of
   585 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   586 INCOMPATIBILITY.
   587 
   588 * Theory Orderings: added class "preorder" as superclass of "order".
   589 INCOMPATIBILITY: Instantiation proofs for order, linorder
   590 etc. slightly changed.  Some theorems named order_class.* now named
   591 preorder_class.*.
   592 
   593 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   594 "diag" to "Id_on".
   595 
   596 * Theory Finite_Set: added a new fold combinator of type
   597 
   598   ('a => 'b => 'b) => 'b => 'a set => 'b
   599 
   600 Occasionally this is more convenient than the old fold combinator
   601 which is now defined in terms of the new one and renamed to
   602 fold_image.
   603 
   604 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   605 and "ring_simps" have been replaced by "algebra_simps" (which can be
   606 extended with further lemmas!).  At the moment both still exist but
   607 the former will disappear at some point.
   608 
   609 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   610 class recpower.  Type-specific simp rules for various recpower types
   611 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   612 
   613 rat_power_0    -> power_0
   614 rat_power_Suc  -> power_Suc
   615 realpow_0      -> power_0
   616 realpow_Suc    -> power_Suc
   617 complexpow_0   -> power_0
   618 complexpow_Suc -> power_Suc
   619 power_poly_0   -> power_0
   620 power_poly_Suc -> power_Suc
   621 
   622 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   623 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   624 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   625 of lemmas from Divides has been generalized from nat to class
   626 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   627 renames resulting from duplicate elimination:
   628 
   629     dvd_def_mod ~>          dvd_eq_mod_eq_0
   630     zero_dvd_iff ~>         dvd_0_left_iff
   631     dvd_0 ~>                dvd_0_right
   632     DIVISION_BY_ZERO_DIV ~> div_by_0
   633     DIVISION_BY_ZERO_MOD ~> mod_by_0
   634     mult_div ~>             div_mult_self2_is_id
   635     mult_mod ~>             mod_mult_self2_is_0
   636 
   637 * Theory IntDiv: removed many lemmas that are instances of class-based
   638 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   639 rename old lemmas as follows:
   640 
   641 dvd_diff               -> nat_dvd_diff
   642 dvd_zminus_iff         -> dvd_minus_iff
   643 mod_add1_eq            -> mod_add_eq
   644 mod_mult1_eq           -> mod_mult_right_eq
   645 mod_mult1_eq'          -> mod_mult_left_eq
   646 mod_mult_distrib_mod   -> mod_mult_eq
   647 nat_mod_add_left_eq    -> mod_add_left_eq
   648 nat_mod_add_right_eq   -> mod_add_right_eq
   649 nat_mod_div_trivial    -> mod_div_trivial
   650 nat_mod_mod_trivial    -> mod_mod_trivial
   651 zdiv_zadd_self1        -> div_add_self1
   652 zdiv_zadd_self2        -> div_add_self2
   653 zdiv_zmult_self1       -> div_mult_self2_is_id
   654 zdiv_zmult_self2       -> div_mult_self1_is_id
   655 zdvd_triv_left         -> dvd_triv_left
   656 zdvd_triv_right        -> dvd_triv_right
   657 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   658 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   659 zmod_zadd_left_eq      -> mod_add_left_eq
   660 zmod_zadd_right_eq     -> mod_add_right_eq
   661 zmod_zadd_self1        -> mod_add_self1
   662 zmod_zadd_self2        -> mod_add_self2
   663 zmod_zadd1_eq          -> mod_add_eq
   664 zmod_zdiff1_eq         -> mod_diff_eq
   665 zmod_zdvd_zmod         -> mod_mod_cancel
   666 zmod_zmod_cancel       -> mod_mod_cancel
   667 zmod_zmult_self1       -> mod_mult_self2_is_0
   668 zmod_zmult_self2       -> mod_mult_self1_is_0
   669 zmod_1                 -> mod_by_1
   670 zdiv_1                 -> div_by_1
   671 zdvd_abs1              -> abs_dvd_iff
   672 zdvd_abs2              -> dvd_abs_iff
   673 zdvd_refl              -> dvd_refl
   674 zdvd_trans             -> dvd_trans
   675 zdvd_zadd              -> dvd_add
   676 zdvd_zdiff             -> dvd_diff
   677 zdvd_zminus_iff        -> dvd_minus_iff
   678 zdvd_zminus2_iff       -> minus_dvd_iff
   679 zdvd_zmultD            -> dvd_mult_right
   680 zdvd_zmultD2           -> dvd_mult_left
   681 zdvd_zmult_mono        -> mult_dvd_mono
   682 zdvd_0_right           -> dvd_0_right
   683 zdvd_0_left            -> dvd_0_left_iff
   684 zdvd_1_left            -> one_dvd
   685 zminus_dvd_iff         -> minus_dvd_iff
   686 
   687 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   688 
   689 * The real numbers offer decimal input syntax: 12.34 is translated
   690 into 1234/10^2. This translation is not reversed upon output.
   691 
   692 * Theory Library/Polynomial defines an abstract type 'a poly of
   693 univariate polynomials with coefficients of type 'a.  In addition to
   694 the standard ring operations, it also supports div and mod.  Code
   695 generation is also supported, using list-style constructors.
   696 
   697 * Theory Library/Inner_Product defines a class of real_inner for real
   698 inner product spaces, with an overloaded operation inner :: 'a => 'a
   699 => real.  Class real_inner is a subclass of real_normed_vector from
   700 theory RealVector.
   701 
   702 * Theory Library/Product_Vector provides instances for the product
   703 type 'a * 'b of several classes from RealVector and Inner_Product.
   704 Definitions of addition, subtraction, scalar multiplication, norms,
   705 and inner products are included.
   706 
   707 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   708 addition to the field operations, numerals and case syntax are also
   709 supported.
   710 
   711 * Theory Library/Diagonalize provides constructive version of Cantor's
   712 first diagonalization argument.
   713 
   714 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   715 zlcm (for int); carried together from various gcd/lcm developements in
   716 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   717 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   718 may recover tupled syntax as follows:
   719 
   720     hide (open) const gcd
   721     abbreviation gcd where
   722       "gcd == (%(a, b). GCD.gcd a b)"
   723     notation (output)
   724       GCD.gcd ("gcd '(_, _')")
   725 
   726 The same works for lcm, zgcd, zlcm.
   727 
   728 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   729 instantiations for algebraic structures.  Removed some duplicate
   730 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   731 
   732 * ML antiquotation @{code} takes a constant as argument and generates
   733 corresponding code in background and inserts name of the corresponding
   734 resulting ML value/function/datatype constructor binding in place.
   735 All occurrences of @{code} with a single ML block are generated
   736 simultaneously.  Provides a generic and safe interface for
   737 instrumentalizing code generation.  See
   738 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   739 In future you ought to refrain from ad-hoc compiling generated SML
   740 code on the ML toplevel.  Note that (for technical reasons) @{code}
   741 cannot refer to constants for which user-defined serializations are
   742 set.  Refer to the corresponding ML counterpart directly in that
   743 cases.
   744 
   745 * Command 'rep_datatype': instead of theorem names the command now
   746 takes a list of terms denoting the constructors of the type to be
   747 represented as datatype.  The characteristic theorems have to be
   748 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   749 have disappeared in favour of existing ones:
   750 
   751     unit_induct                 ~> unit.induct
   752     prod_induct                 ~> prod.induct
   753     sum_induct                  ~> sum.induct
   754     Suc_Suc_eq                  ~> nat.inject
   755     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   756 
   757 
   758 *** HOL-Algebra ***
   759 
   760 * New locales for orders and lattices where the equivalence relation
   761 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   762 locales use a record structure with field eq for the equivalence.
   763 
   764 * New theory of factorial domains.
   765 
   766 * Units_l_inv and Units_r_inv are now simp rules by default.
   767 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   768 and/or r_inv will now also require deletion of these lemmas.
   769 
   770 * Renamed the following theorems, INCOMPATIBILITY:
   771 
   772 UpperD ~> Upper_memD
   773 LowerD ~> Lower_memD
   774 least_carrier ~> least_closed
   775 greatest_carrier ~> greatest_closed
   776 greatest_Lower_above ~> greatest_Lower_below
   777 one_zero ~> carrier_one_zero
   778 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   779 
   780 
   781 *** HOL-Nominal ***
   782 
   783 * Nominal datatypes can now contain type-variables.
   784 
   785 * Commands 'nominal_inductive' and 'equivariance' work with local
   786 theory targets.
   787 
   788 * Nominal primrec can now works with local theory targets and its
   789 specification syntax now conforms to the general format as seen in
   790 'inductive' etc.
   791 
   792 * Method "perm_simp" honours the standard simplifier attributes
   793 (no_asm), (no_asm_use) etc.
   794 
   795 * The new predicate #* is defined like freshness, except that on the
   796 left hand side can be a set or list of atoms.
   797 
   798 * Experimental command 'nominal_inductive2' derives strong induction
   799 principles for inductive definitions.  In contrast to
   800 'nominal_inductive', which can only deal with a fixed number of
   801 binders, it can deal with arbitrary expressions standing for sets of
   802 atoms to be avoided.  The only inductive definition we have at the
   803 moment that needs this generalisation is the typing rule for Lets in
   804 the algorithm W:
   805 
   806  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   807  -----------------------------------------------------------------
   808          Gamma |- Let x be t1 in t2 : T2
   809 
   810 In this rule one wants to avoid all the binders that are introduced by
   811 "close Gamma T1".  We are looking for other examples where this
   812 feature might be useful.  Please let us know.
   813 
   814 
   815 *** HOLCF ***
   816 
   817 * Reimplemented the simplification procedure for proving continuity
   818 subgoals.  The new simproc is extensible; users can declare additional
   819 continuity introduction rules with the attribute [cont2cont].
   820 
   821 * The continuity simproc now uses a different introduction rule for
   822 solving continuity subgoals on terms with lambda abstractions.  In
   823 some rare cases the new simproc may fail to solve subgoals that the
   824 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   825 Potential INCOMPATIBILITY.
   826 
   827 * Command 'fixrec': specification syntax now conforms to the general
   828 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   829 examples.  INCOMPATIBILITY.
   830 
   831 
   832 *** ZF ***
   833 
   834 * Proof of Zorn's Lemma for partial orders.
   835 
   836 
   837 *** ML ***
   838 
   839 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   840 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   841 depends on multithreading, so timouts will not work before Poly/ML
   842 5.2.1!
   843 
   844 * High-level support for concurrent ML programming, see
   845 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   846 particularly convenient to organize independent functional
   847 computations.  The concept of "synchronized variables" provides a
   848 higher-order interface for components with shared state, avoiding the
   849 delicate details of mutexes and condition variables.  (Requires
   850 Poly/ML 5.2.1 or later.)
   851 
   852 * ML bindings produced via Isar commands are stored within the Isar
   853 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   854 become thread-safe and work with undo as expected (concerning
   855 top-level bindings, not side-effects on global references).
   856 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   857 compiler at runtime; really global bindings need to be given outside a
   858 theory.  (Requires Poly/ML 5.2 or later.)
   859 
   860 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   861 context.  Top-level ML bindings are stored within the proof context in
   862 a purely sequential fashion, disregarding the nested proof structure.
   863 ML bindings introduced by 'ML_prf' are discarded at the end of the
   864 proof.  (Requires Poly/ML 5.2 or later.)
   865 
   866 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   867 and Method.setup, as well as Isar commands 'attribute_setup' and
   868 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   869 existing code accordingly, or use plain 'setup' together with old
   870 Method.add_method.
   871 
   872 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   873 to 'a -> thm, while results are always tagged with an authentic oracle
   874 name.  The Isar command 'oracle' is now polymorphic, no argument type
   875 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   876 accordingly.  Note that extra performance may be gained by producing
   877 the cterm carefully, avoiding slow Thm.cterm_of.
   878 
   879 * Simplified interface for defining document antiquotations via
   880 ThyOutput.antiquotation, ThyOutput.output, and optionally
   881 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   882 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   883 examples.
   884 
   885 * More systematic treatment of long names, abstract name bindings, and
   886 name space operations.  Basic operations on qualified names have been
   887 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   888 Long_Name.append.  Old type bstring has been mostly replaced by
   889 abstract type binding (see structure Binding), which supports precise
   890 qualification by packages and local theory targets, as well as proper
   891 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   892 bstring values into Binding.name, or better pass through abstract
   893 bindings everywhere.  See further src/Pure/General/long_name.ML,
   894 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   895 
   896 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   897 LocalTheory.note etc.) now refer to the *full* internal name, not the
   898 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   899 
   900 * Disposed old type and term read functions (Sign.read_def_typ,
   901 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   902 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   903 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   904 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   905 resort for legacy applications.
   906 
   907 * Disposed old declarations, tactics, tactic combinators that refer to
   908 the simpset or claset of an implicit theory (such as Addsimps,
   909 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   910 embedded ML text, or local_simpset_of with a proper context passed as
   911 explicit runtime argument.
   912 
   913 * Rules and tactics that read instantiations (read_instantiate,
   914 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   915 context, which is required for parsing and type-checking.  Moreover,
   916 the variables are specified as plain indexnames, not string encodings
   917 thereof.  INCOMPATIBILITY.
   918 
   919 * Generic Toplevel.add_hook interface allows to analyze the result of
   920 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   921 for theorem dependency output of transactions resulting in a new
   922 theory state.
   923 
   924 * ML antiquotations: block-structured compilation context indicated by
   925 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   926 
   927   @{binding name}                         - basic name binding
   928   @{let ?pat = term}                      - term abbreviation (HO matching)
   929   @{note name = fact}                     - fact abbreviation
   930   @{thm fact}                             - singleton fact (with attributes)
   931   @{thms fact}                            - general fact (with attributes)
   932   @{lemma prop by method}                 - singleton goal
   933   @{lemma prop by meth1 meth2}            - singleton goal
   934   @{lemma prop1 ... propN by method}      - general goal
   935   @{lemma prop1 ... propN by meth1 meth2} - general goal
   936   @{lemma (open) ...}                     - open derivation
   937 
   938 
   939 *** System ***
   940 
   941 * The Isabelle "emacs" tool provides a specific interface to invoke
   942 Proof General / Emacs, with more explicit failure if that is not
   943 installed (the old isabelle-interface script silently falls back on
   944 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   945 installation location of the Proof General distribution.
   946 
   947 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   948 the Isabelle process into a JVM/Scala application.  See
   949 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   950 process wrapper has been discontinued.)
   951 
   952 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   953 
   954 * Various status messages (with exact source position information) are
   955 emitted, if proper markup print mode is enabled.  This allows
   956 user-interface components to provide detailed feedback on internal
   957 prover operations.
   958 
   959 
   960 
   961 New in Isabelle2008 (June 2008)
   962 -------------------------------
   963 
   964 *** General ***
   965 
   966 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   967 and updated, with formally checked references as hyperlinks.
   968 
   969 * Theory loader: use_thy (and similar operations) no longer set the
   970 implicit ML context, which was occasionally hard to predict and in
   971 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   972 provides a proper context already.
   973 
   974 * Theory loader: old-style ML proof scripts being *attached* to a thy
   975 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   976 'use' within a theory file will do the job.
   977 
   978 * Name space merge now observes canonical order, i.e. the second space
   979 is inserted into the first one, while existing entries in the first
   980 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   981 swap theory imports.
   982 
   983 * Syntax: symbol \<chi> is now considered a letter.  Potential
   984 INCOMPATIBILITY in identifier syntax etc.
   985 
   986 * Outer syntax: string tokens no longer admit escaped white space,
   987 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   988 white space without escapes.
   989 
   990 * Outer syntax: string tokens may contain arbitrary character codes
   991 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   992 "foo_bar".
   993 
   994 
   995 *** Pure ***
   996 
   997 * Context-dependent token translations.  Default setup reverts locally
   998 fixed variables, and adds hilite markup for undeclared frees.
   999 
  1000 * Unused theorems can be found using the new command 'unused_thms'.
  1001 There are three ways of invoking it:
  1002 
  1003 (1) unused_thms
  1004      Only finds unused theorems in the current theory.
  1005 
  1006 (2) unused_thms thy_1 ... thy_n -
  1007      Finds unused theorems in the current theory and all of its ancestors,
  1008      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1009 
  1010 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1011      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1012      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1013      their ancestors.
  1014 
  1015 In order to increase the readability of the list produced by
  1016 unused_thms, theorems that have been created by a particular instance
  1017 of a theory command such as 'inductive' or 'function' are considered
  1018 to belong to the same "group", meaning that if at least one theorem in
  1019 this group is used, the other theorems in the same group are no longer
  1020 reported as unused.  Moreover, if all theorems in the group are
  1021 unused, only one theorem in the group is displayed.
  1022 
  1023 Note that proof objects have to be switched on in order for
  1024 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1025 usually the case when using Proof General with the default settings).
  1026 
  1027 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1028 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1029 duplicate fact bindings, or even accidental fact duplications.  Note
  1030 that tools may maintain dynamically scoped facts systematically, using
  1031 PureThy.add_thms_dynamic.
  1032 
  1033 * Command 'hide' now allows to hide from "fact" name space as well.
  1034 
  1035 * Eliminated destructive theorem database, simpset, claset, and
  1036 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1037 update of theories within ML code.
  1038 
  1039 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1040 INCOMPATIBILITY, object-logics depending on former Pure require
  1041 additional setup PureThy.old_appl_syntax_setup; object-logics
  1042 depending on former CPure need to refer to Pure.
  1043 
  1044 * Commands 'use' and 'ML' are now purely functional, operating on
  1045 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1046 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1047 INCOMPATIBILITY.
  1048 
  1049 * Command 'setup': discontinued implicit version with ML reference.
  1050 
  1051 * Instantiation target allows for simultaneous specification of class
  1052 instance operations together with an instantiation proof.
  1053 Type-checking phase allows to refer to class operations uniformly.
  1054 See src/HOL/Complex/Complex.thy for an Isar example and
  1055 src/HOL/Library/Eval.thy for an ML example.
  1056 
  1057 * Indexing of literal facts: be more serious about including only
  1058 facts from the visible specification/proof context, but not the
  1059 background context (locale etc.).  Affects `prop` notation and method
  1060 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1061 situations.
  1062 
  1063 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1064 "(open)" option, which used to expose internal bound variables to the
  1065 proof text.
  1066 
  1067 * Isar statements: removed obsolete case "rule_context".
  1068 INCOMPATIBILITY, better use explicit fixes/assumes.
  1069 
  1070 * Locale proofs: default proof step now includes 'unfold_locales';
  1071 hence 'proof' without argument may be used to unfold locale
  1072 predicates.
  1073 
  1074 
  1075 *** Document preparation ***
  1076 
  1077 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1078 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1079 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1080 spot); renamed link color from "darkblue" to "linkcolor" (default
  1081 value unchanged, can be redefined via \definecolor); no longer sets
  1082 "a4paper" option (unnecessary or even intrusive).
  1083 
  1084 * Antiquotation @{lemma A method} proves proposition A by the given
  1085 method (either a method name or a method name plus (optional) method
  1086 arguments in parentheses) and prints A just like @{prop A}.
  1087 
  1088 
  1089 *** HOL ***
  1090 
  1091 * New primrec package.  Specification syntax conforms in style to
  1092 definition/function/....  No separate induction rule is provided.  The
  1093 "primrec" command distinguishes old-style and new-style specifications
  1094 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1095 When adjusting theories, beware: constants stemming from new-style
  1096 primrec specifications have authentic syntax.
  1097 
  1098 * Metis prover is now an order of magnitude faster, and also works
  1099 with multithreading.
  1100 
  1101 * Metis: the maximum number of clauses that can be produced from a
  1102 theorem is now given by the attribute max_clauses.  Theorems that
  1103 exceed this number are ignored, with a warning printed.
  1104 
  1105 * Sledgehammer no longer produces structured proofs by default. To
  1106 enable, declare [[sledgehammer_full = true]].  Attributes
  1107 reconstruction_modulus, reconstruction_sorts renamed
  1108 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1109 
  1110 * Method "induct_scheme" derives user-specified induction rules
  1111 from well-founded induction and completeness of patterns. This factors
  1112 out some operations that are done internally by the function package
  1113 and makes them available separately.  See
  1114 src/HOL/ex/Induction_Scheme.thy for examples.
  1115 
  1116 * More flexible generation of measure functions for termination
  1117 proofs: Measure functions can be declared by proving a rule of the
  1118 form "is_measure f" and giving it the [measure_function] attribute.
  1119 The "is_measure" predicate is logically meaningless (always true), and
  1120 just guides the heuristic.  To find suitable measure functions, the
  1121 termination prover sets up the goal "is_measure ?f" of the appropriate
  1122 type and generates all solutions by prolog-style backwards proof using
  1123 the declared rules.
  1124 
  1125 This setup also deals with rules like 
  1126 
  1127   "is_measure f ==> is_measure (list_size f)"
  1128 
  1129 which accommodates nested datatypes that recurse through lists.
  1130 Similar rules are predeclared for products and option types.
  1131 
  1132 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1133 
  1134   INCOMPATIBILITIES:
  1135 
  1136   - Definitions of overloaded constants on sets have to be replaced by
  1137     definitions on => and bool.
  1138 
  1139   - Some definitions of overloaded operators on sets can now be proved
  1140     using the definitions of the operators on => and bool.  Therefore,
  1141     the following theorems have been renamed:
  1142 
  1143       subset_def   -> subset_eq
  1144       psubset_def  -> psubset_eq
  1145       set_diff_def -> set_diff_eq
  1146       Compl_def    -> Compl_eq
  1147       Sup_set_def  -> Sup_set_eq
  1148       Inf_set_def  -> Inf_set_eq
  1149       sup_set_def  -> sup_set_eq
  1150       inf_set_def  -> inf_set_eq
  1151 
  1152   - Due to the incompleteness of the HO unification algorithm, some
  1153     rules such as subst may require manual instantiation, if some of
  1154     the unknowns in the rule is a set.
  1155 
  1156   - Higher order unification and forward proofs:
  1157     The proof pattern
  1158 
  1159       have "P (S::'a set)" <...>
  1160       then have "EX S. P S" ..
  1161 
  1162     no longer works (due to the incompleteness of the HO unification
  1163     algorithm) and must be replaced by the pattern
  1164 
  1165       have "EX S. P S"
  1166       proof
  1167         show "P S" <...>
  1168       qed
  1169 
  1170   - Calculational reasoning with subst (or similar rules):
  1171     The proof pattern
  1172 
  1173       have "P (S::'a set)" <...>
  1174       also have "S = T" <...>
  1175       finally have "P T" .
  1176 
  1177     no longer works (for similar reasons as the previous example) and
  1178     must be replaced by something like
  1179 
  1180       have "P (S::'a set)" <...>
  1181       moreover have "S = T" <...>
  1182       ultimately have "P T" by simp
  1183 
  1184   - Tactics or packages written in ML code:
  1185     Code performing pattern matching on types via
  1186 
  1187       Type ("set", [T]) => ...
  1188 
  1189     must be rewritten. Moreover, functions like strip_type or
  1190     binder_types no longer return the right value when applied to a
  1191     type of the form
  1192 
  1193       T1 => ... => Tn => U => bool
  1194 
  1195     rather than
  1196 
  1197       T1 => ... => Tn => U set
  1198 
  1199 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1200 Wellfounded_Relations to theory Wellfounded.
  1201 
  1202 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1203 
  1204 * Class finite no longer treats UNIV as class parameter.  Use class
  1205 enum from theory Library/Enum instead to achieve a similar effect.
  1206 INCOMPATIBILITY.
  1207 
  1208 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1209 and "Cons".  INCOMPATIBILITY.
  1210 
  1211 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1212 Potential INCOMPATIBILITY.
  1213 
  1214 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1215 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1216 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1217 
  1218 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1219 the same name in theory Orderings:
  1220 
  1221   less_trans
  1222   less_linear
  1223   le_imp_less_or_eq
  1224   le_less_trans
  1225   less_le_trans
  1226   less_not_sym
  1227   less_asym
  1228 
  1229 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1230 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1231 and different variable names.
  1232 
  1233 * Library/Option_ord.thy: Canonical order on option type.
  1234 
  1235 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1236 finite maps.
  1237 
  1238 * Library/Countable.thy: Type class for countable types.
  1239 
  1240 * Theory Int: The representation of numerals has changed.  The infix
  1241 operator BIT and the bit datatype with constructors B0 and B1 have
  1242 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1243 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1244 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1245 accordingly.
  1246 
  1247 * Theory Nat: definition of <= and < on natural numbers no longer
  1248 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1249 le_def and less_def have disappeared.  Consider lemmas not_less
  1250 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1251 
  1252 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1253 (whose purpose mainly is for various fold_set functionals) have been
  1254 abandoned in favor of the existing algebraic classes
  1255 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1256 lower_semilattice (resp. upper_semilattice) and linorder.
  1257 INCOMPATIBILITY.
  1258 
  1259 * Theory Transitive_Closure: induct and cases rules now declare proper
  1260 case_names ("base" and "step").  INCOMPATIBILITY.
  1261 
  1262 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1263 lattices.  The form set-specific version is available as
  1264 Inductive.lfp_ordinal_induct_set.
  1265 
  1266 * Renamed theorems "power.simps" to "power_int.simps".
  1267 INCOMPATIBILITY.
  1268 
  1269 * Class semiring_div provides basic abstract properties of semirings
  1270 with division and modulo operations.  Subsumes former class dvd_mod.
  1271 
  1272 * Merged theories IntDef, Numeral and IntArith into unified theory
  1273 Int.  INCOMPATIBILITY.
  1274 
  1275 * Theory Library/Code_Index: type "index" now represents natural
  1276 numbers rather than integers.  INCOMPATIBILITY.
  1277 
  1278 * New class "uminus" with operation "uminus" (split of from class
  1279 "minus" which now only has operation "minus", binary).
  1280 INCOMPATIBILITY.
  1281 
  1282 * Constants "card", "internal_split", "option_map" now with authentic
  1283 syntax.  INCOMPATIBILITY.
  1284 
  1285 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1286 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1287 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1288 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1289 Sup_set_def, le_def, less_def, option_map_def now with object
  1290 equality.  INCOMPATIBILITY.
  1291 
  1292 * Records. Removed K_record, and replaced it by pure lambda term
  1293 %x. c. The simplifier setup is now more robust against eta expansion.
  1294 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1295 
  1296 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1297 
  1298 * Library/ListVector: new theory of arithmetic vector operations.
  1299 
  1300 * Library/Order_Relation: new theory of various orderings as sets of
  1301 pairs.  Defines preorders, partial orders, linear orders and
  1302 well-orders on sets and on types.
  1303 
  1304 
  1305 *** ZF ***
  1306 
  1307 * Renamed some theories to allow to loading both ZF and HOL in the
  1308 same session:
  1309 
  1310   Datatype  -> Datatype_ZF
  1311   Inductive -> Inductive_ZF
  1312   Int       -> Int_ZF
  1313   IntDiv    -> IntDiv_ZF
  1314   Nat       -> Nat_ZF
  1315   List      -> List_ZF
  1316   Main      -> Main_ZF
  1317 
  1318 INCOMPATIBILITY: ZF theories that import individual theories below
  1319 Main might need to be adapted.  Regular theory Main is still
  1320 available, as trivial extension of Main_ZF.
  1321 
  1322 
  1323 *** ML ***
  1324 
  1325 * ML within Isar: antiquotation @{const name} or @{const
  1326 name(typargs)} produces statically-checked Const term.
  1327 
  1328 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1329 (of the same name).  Removed obsolete print command.
  1330 
  1331 * Removed obsolete "use_legacy_bindings" function.
  1332 
  1333 * The ``print mode'' is now a thread-local value derived from a global
  1334 template (the former print_mode reference), thus access becomes
  1335 non-critical.  The global print_mode reference is for session
  1336 management only; user-code should use print_mode_value,
  1337 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1338 
  1339 * Functions system/system_out provide a robust way to invoke external
  1340 shell commands, with propagation of interrupts (requires Poly/ML
  1341 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1342 
  1343 
  1344 *** System ***
  1345 
  1346 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1347 in accordance with Proof General 3.7, which prefers GNU emacs.
  1348 
  1349 * isatool tty runs Isabelle process with plain tty interaction;
  1350 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1351 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1352 
  1353 * isatool browser now works with Cygwin as well, using general
  1354 "javapath" function defined in Isabelle process environment.
  1355 
  1356 * YXML notation provides a simple and efficient alternative to
  1357 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1358 isatool yxml as described in the Isabelle system manual.
  1359 
  1360 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1361 provides general wrapper for managing an Isabelle process in a robust
  1362 fashion, with ``cooked'' output from stdin/stderr.
  1363 
  1364 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1365 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1366 
  1367 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1368 way of changing the user's settings is via
  1369 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1370 script.
  1371 
  1372 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1373 cores of the underlying machine, which is a good starting point for
  1374 optimal performance tuning.  The corresponding usedir option -M allows
  1375 "max" as an alias for "0".  WARNING: does not work on certain versions
  1376 of Mac OS (with Poly/ML 5.1).
  1377 
  1378 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1379 adverse effect of Isabelle flooding interactive front-ends (notably
  1380 ProofGeneral / XEmacs).
  1381 
  1382 
  1383 
  1384 New in Isabelle2007 (November 2007)
  1385 -----------------------------------
  1386 
  1387 *** General ***
  1388 
  1389 * More uniform information about legacy features, notably a
  1390 warning/error of "Legacy feature: ...", depending on the state of the
  1391 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1392 legacy features will disappear eventually.
  1393 
  1394 * Theory syntax: the header format ``theory A = B + C:'' has been
  1395 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1396 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1397 
  1398 * Theory syntax: the old non-Isar theory file format has been
  1399 discontinued altogether.  Note that ML proof scripts may still be used
  1400 with Isar theories; migration is usually quite simple with the ML
  1401 function use_legacy_bindings.  INCOMPATIBILITY.
  1402 
  1403 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1404 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1405 quotes.
  1406 
  1407 * Theory loader: be more serious about observing the static theory
  1408 header specifications (including optional directories), but not the
  1409 accidental file locations of previously successful loads.  The strict
  1410 update policy of former update_thy is now already performed by
  1411 use_thy, so the former has been removed; use_thys updates several
  1412 theories simultaneously, just as 'imports' within a theory header
  1413 specification, but without merging the results.  Potential
  1414 INCOMPATIBILITY: may need to refine theory headers and commands
  1415 ROOT.ML which depend on load order.
  1416 
  1417 * Theory loader: optional support for content-based file
  1418 identification, instead of the traditional scheme of full physical
  1419 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1420 (cf. the system manual).  The new scheme allows to work with
  1421 non-finished theories in persistent session images, such that source
  1422 files may be moved later on without requiring reloads.
  1423 
  1424 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1425 file (with the same base name as the theory) are considered a legacy
  1426 feature, which will disappear eventually. Even now, the theory loader
  1427 no longer maintains dependencies on such files.
  1428 
  1429 * Syntax: the scope for resolving ambiguities via type-inference is
  1430 now limited to individual terms, instead of whole simultaneous
  1431 specifications as before. This greatly reduces the complexity of the
  1432 syntax module and improves flexibility by separating parsing and
  1433 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1434 'fixes' etc.) are required in rare situations.
  1435 
  1436 * Syntax: constants introduced by new-style packages ('definition',
  1437 'abbreviation' etc.) are passed through the syntax module in
  1438 ``authentic mode''. This means that associated mixfix annotations
  1439 really stick to such constants, independently of potential name space
  1440 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1441 trees are represented slightly differently, may need to adapt syntax
  1442 translations accordingly. Use CONST marker in 'translations' and
  1443 @{const_syntax} antiquotation in 'parse_translation' etc.
  1444 
  1445 * Legacy goal package: reduced interface to the bare minimum required
  1446 to keep existing proof scripts running.  Most other user-level
  1447 functions are now part of the OldGoals structure, which is *not* open
  1448 by default (consider isatool expandshort before open OldGoals).
  1449 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1450 these tend to cause confusion about the actual goal (!) context being
  1451 used here, which is not necessarily the same as the_context().
  1452 
  1453 * Command 'find_theorems': supports "*" wild-card in "name:"
  1454 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1455 support a specific search form (see ProofGeneral/CHANGES).
  1456 
  1457 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1458 by default, which means that "prems" (and also "fixed variables") are
  1459 suppressed from proof state output.  Note that the ProofGeneral
  1460 settings mechanism allows to change and save options persistently, but
  1461 older versions of Isabelle will fail to start up if a negative prems
  1462 limit is imposed.
  1463 
  1464 * Local theory targets may be specified by non-nested blocks of
  1465 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1466 contain definitions, theorems etc., including any derived mechanism
  1467 that has been implemented on top of these primitives.  This concept
  1468 generalizes the existing ``theorem (in ...)'' towards more versatility
  1469 and scalability.
  1470 
  1471 * Proof General interface: proper undo of final 'end' command;
  1472 discontinued Isabelle/classic mode (ML proof scripts).
  1473 
  1474 
  1475 *** Document preparation ***
  1476 
  1477 * Added antiquotation @{theory name} which prints the given name,
  1478 after checking that it refers to a valid ancestor theory in the
  1479 current context.
  1480 
  1481 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1482 check the given source text as ML type/structure, printing verbatim.
  1483 
  1484 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1485 "c args == rhs" given in the current context.  (Any number of
  1486 arguments may be given on the LHS.)
  1487 
  1488 
  1489 *** Pure ***
  1490 
  1491 * The 'class' package offers a combination of axclass and locale to
  1492 achieve Haskell-like type classes in Isabelle.  Definitions and
  1493 theorems within a class context produce both relative results (with
  1494 implicit parameters according to the locale context), and polymorphic
  1495 constants with qualified polymorphism (according to the class
  1496 context).  Within the body context of a 'class' target, a separate
  1497 syntax layer ("user space type system") takes care of converting
  1498 between global polymorphic consts and internal locale representation.
  1499 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1500 "isatool doc classes" provides a tutorial.
  1501 
  1502 * Generic code generator framework allows to generate executable
  1503 code for ML and Haskell (including Isabelle classes).  A short usage
  1504 sketch:
  1505 
  1506     internal compilation:
  1507         export_code <list of constants (term syntax)> in SML
  1508     writing SML code to a file:
  1509         export_code <list of constants (term syntax)> in SML <filename>
  1510     writing OCaml code to a file:
  1511         export_code <list of constants (term syntax)> in OCaml <filename>
  1512     writing Haskell code to a bunch of files:
  1513         export_code <list of constants (term syntax)> in Haskell <filename>
  1514 
  1515     evaluating closed propositions to True/False using code generation:
  1516         method ``eval''
  1517 
  1518 Reasonable default setup of framework in HOL.
  1519 
  1520 Theorem attributs for selecting and transforming function equations theorems:
  1521 
  1522     [code fun]:        select a theorem as function equation for a specific constant
  1523     [code fun del]:    deselect a theorem as function equation for a specific constant
  1524     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1525     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1526 
  1527 User-defined serializations (target in {SML, OCaml, Haskell}):
  1528 
  1529     code_const <and-list of constants (term syntax)>
  1530       {(target) <and-list of const target syntax>}+
  1531 
  1532     code_type <and-list of type constructors>
  1533       {(target) <and-list of type target syntax>}+
  1534 
  1535     code_instance <and-list of instances>
  1536       {(target)}+
  1537         where instance ::= <type constructor> :: <class>
  1538 
  1539     code_class <and_list of classes>
  1540       {(target) <and-list of class target syntax>}+
  1541         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1542 
  1543 code_instance and code_class only are effective to target Haskell.
  1544 
  1545 For example usage see src/HOL/ex/Codegenerator.thy and
  1546 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1547 generation from Isabelle/HOL theories is available via "isatool doc
  1548 codegen".
  1549 
  1550 * Code generator: consts in 'consts_code' Isar commands are now
  1551 referred to by usual term syntax (including optional type
  1552 annotations).
  1553 
  1554 * Command 'no_translations' removes translation rules from theory
  1555 syntax.
  1556 
  1557 * Overloaded definitions are now actually checked for acyclic
  1558 dependencies.  The overloading scheme is slightly more general than
  1559 that of Haskell98, although Isabelle does not demand an exact
  1560 correspondence to type class and instance declarations.
  1561 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1562 exotic versions of overloading -- at the discretion of the user!
  1563 
  1564 Polymorphic constants are represented via type arguments, i.e. the
  1565 instantiation that matches an instance against the most general
  1566 declaration given in the signature.  For example, with the declaration
  1567 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1568 as c(nat).  Overloading is essentially simultaneous structural
  1569 recursion over such type arguments.  Incomplete specification patterns
  1570 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1571 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1572 Command 'print_theory' outputs the normalized system of recursive
  1573 equations, see section "definitions".
  1574 
  1575 * Configuration options are maintained within the theory or proof
  1576 context (with name and type bool/int/string), providing a very simple
  1577 interface to a poor-man's version of general context data.  Tools may
  1578 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1579 these values using Config.get etc.  Users may change options via an
  1580 associated attribute of the same name.  This form of context
  1581 declaration works particularly well with commands 'declare' or
  1582 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1583 very easy to avoid global references, which would not observe Isar
  1584 toplevel undo/redo and fail to work with multithreading.
  1585 
  1586 Various global ML references of Pure and HOL have been turned into
  1587 configuration options:
  1588 
  1589   Unify.search_bound		unify_search_bound
  1590   Unify.trace_bound		unify_trace_bound
  1591   Unify.trace_simp		unify_trace_simp
  1592   Unify.trace_types		unify_trace_types
  1593   Simplifier.simp_depth_limit	simp_depth_limit
  1594   Blast.depth_limit		blast_depth_limit
  1595   DatatypeProp.dtK		datatype_distinctness_limit
  1596   fast_arith_neq_limit  	fast_arith_neq_limit
  1597   fast_arith_split_limit	fast_arith_split_limit
  1598 
  1599 * Named collections of theorems may be easily installed as context
  1600 data using the functor NamedThmsFun (see also
  1601 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1602 attributes; there is also a toplevel print command.  This facility is
  1603 just a common case of general context data, which is the preferred way
  1604 for anything more complex than just a list of facts in canonical
  1605 order.
  1606 
  1607 * Isar: command 'declaration' augments a local theory by generic
  1608 declaration functions written in ML.  This enables arbitrary content
  1609 being added to the context, depending on a morphism that tells the
  1610 difference of the original declaration context wrt. the application
  1611 context encountered later on.
  1612 
  1613 * Isar: proper interfaces for simplification procedures.  Command
  1614 'simproc_setup' declares named simprocs (with match patterns, and body
  1615 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1616 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1617 
  1618 * Isar: an extra pair of brackets around attribute declarations
  1619 abbreviates a theorem reference involving an internal dummy fact,
  1620 which will be ignored later --- only the effect of the attribute on
  1621 the background context will persist.  This form of in-place
  1622 declarations is particularly useful with commands like 'declare' and
  1623 'using', for example ``have A using [[simproc a]] by simp''.
  1624 
  1625 * Isar: method "assumption" (and implicit closing of subproofs) now
  1626 takes simple non-atomic goal assumptions into account: after applying
  1627 an assumption as a rule the resulting subgoals are solved by atomic
  1628 assumption steps.  This is particularly useful to finish 'obtain'
  1629 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1630 without referring to the original premise "!!x. P x ==> thesis" in the
  1631 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1632 more permissive.
  1633 
  1634 * Isar: implicit use of prems from the Isar proof context is
  1635 considered a legacy feature.  Common applications like ``have A .''
  1636 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1637 referencing facts explicitly here improves readability and
  1638 maintainability of proof texts.
  1639 
  1640 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1641 the obtained context from the course of reasoning!  For example:
  1642 
  1643   assume "EX x y. A x & B y"   -- "any previous fact"
  1644   then guess x and y by clarify
  1645 
  1646 This technique is potentially adventurous, depending on the facts and
  1647 proof tools being involved here.
  1648 
  1649 * Isar: known facts from the proof context may be specified as literal
  1650 propositions, using ASCII back-quote syntax.  This works wherever
  1651 named facts used to be allowed so far, in proof commands, proof
  1652 methods, attributes etc.  Literal facts are retrieved from the context
  1653 according to unification of type and term parameters.  For example,
  1654 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1655 theorems in the current context, then these are valid literal facts:
  1656 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1657 
  1658 There is also a proof method "fact" which does the same composition
  1659 for explicit goal states, e.g. the following proof texts coincide with
  1660 certain special cases of literal facts:
  1661 
  1662   have "A" by fact                 ==  note `A`
  1663   have "A ==> B" by fact           ==  note `A ==> B`
  1664   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1665   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1666 
  1667 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1668 outer syntax.  Thus symbolic identifiers may be used without
  1669 additional white space in declarations like this: ``assume *: A''.
  1670 
  1671 * Isar: 'print_facts' prints all local facts of the current context,
  1672 both named and unnamed ones.
  1673 
  1674 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1675 
  1676   def x == "t" and y == "u"
  1677 
  1678 * Isar: added command 'unfolding', which is structurally similar to
  1679 'using', but affects both the goal state and facts by unfolding given
  1680 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1681 'unfolded' attribute may be replaced by first-class proof text.
  1682 
  1683 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1684 and command 'unfolding' now all support object-level equalities
  1685 (potentially conditional).  The underlying notion of rewrite rule is
  1686 analogous to the 'rule_format' attribute, but *not* that of the
  1687 Simplifier (which is usually more generous).
  1688 
  1689 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1690 premises of a theorem by n. Useful in conjunction with drule.
  1691 
  1692 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1693 method expression within a sandbox consisting of the first N
  1694 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1695 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1696 simplifies all new goals that emerge from applying rule foo to the
  1697 originally first one.
  1698 
  1699 * Isar: schematic goals are no longer restricted to higher-order
  1700 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1701 expected.
  1702 
  1703 * Isar: the conclusion of a long theorem statement is now either
  1704 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1705 (essentially a disjunction of cases with local parameters and
  1706 assumptions).  The latter allows to express general elimination rules
  1707 adequately; in this notation common elimination rules look like this:
  1708 
  1709   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1710     assumes "EX x. P x"
  1711     obtains x where "P x"
  1712 
  1713   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1714     assumes "A & B"
  1715     obtains A and B
  1716 
  1717   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1718     assumes "A | B"
  1719     obtains
  1720       A
  1721     | B
  1722 
  1723 The subsequent classical rules even refer to the formal "thesis"
  1724 explicitly:
  1725 
  1726   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1727     obtains "~ thesis"
  1728 
  1729   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1730     obtains "thesis ==> something"
  1731 
  1732 The actual proof of an 'obtains' statement is analogous to that of the
  1733 Isar proof element 'obtain', only that there may be several cases.
  1734 Optional case names may be specified in parentheses; these will be
  1735 available both in the present proof and as annotations in the
  1736 resulting rule, for later use with the 'cases' method (cf. attribute
  1737 case_names).
  1738 
  1739 * Isar: the assumptions of a long theorem statement are available as
  1740 "assms" fact in the proof context.  This is more appropriate than the
  1741 (historical) "prems", which refers to all assumptions of the current
  1742 context, including those from the target locale, proof body etc.
  1743 
  1744 * Isar: 'print_statement' prints theorems from the current theory or
  1745 proof context in long statement form, according to the syntax of a
  1746 top-level lemma.
  1747 
  1748 * Isar: 'obtain' takes an optional case name for the local context
  1749 introduction rule (default "that").
  1750 
  1751 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1752 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1753 to occur.
  1754 
  1755 * Pure: syntax "CONST name" produces a fully internalized constant
  1756 according to the current context.  This is particularly useful for
  1757 syntax translations that should refer to internal constant
  1758 representations independently of name spaces.
  1759 
  1760 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1761 instead of "FOO ". This allows multiple binder declarations to coexist
  1762 in the same context.  INCOMPATIBILITY.
  1763 
  1764 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1765 primitive that also works in a locale context (both for constants and
  1766 fixed variables). Type declaration and internal syntactic representation
  1767 of given constants retrieved from the context. Likewise, the
  1768 'no_notation' command allows to remove given syntax annotations from the
  1769 current context.
  1770 
  1771 * Isar/locales: new derived specification elements 'axiomatization',
  1772 'definition', 'abbreviation', which support type-inference, admit
  1773 object-level specifications (equality, equivalence).  See also the
  1774 isar-ref manual.  Examples:
  1775 
  1776   axiomatization
  1777     eq  (infix "===" 50) where
  1778     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1779 
  1780   definition "f x y = x + y + 1"
  1781   definition g where "g x = f x x"
  1782 
  1783   abbreviation
  1784     neq  (infix "=!=" 50) where
  1785     "x =!= y == ~ (x === y)"
  1786 
  1787 These specifications may be also used in a locale context.  Then the
  1788 constants being introduced depend on certain fixed parameters, and the
  1789 constant name is qualified by the locale base name.  An internal
  1790 abbreviation takes care for convenient input and output, making the
  1791 parameters implicit and using the original short name.  See also
  1792 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1793 entities from a monomorphic theory.
  1794 
  1795 Presently, abbreviations are only available 'in' a target locale, but
  1796 not inherited by general import expressions.  Also note that
  1797 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1798 'translations' in common applications.  The "no_abbrevs" print mode
  1799 prevents folding of abbreviations in term output.
  1800 
  1801 Concrete syntax is attached to specified constants in internal form,
  1802 independently of name spaces.  The parse tree representation is
  1803 slightly different -- use 'notation' instead of raw 'syntax', and
  1804 'translations' with explicit "CONST" markup to accommodate this.
  1805 
  1806 * Pure/Isar: unified syntax for new-style specification mechanisms
  1807 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1808 full type inference and dummy patterns ("_").  For example:
  1809 
  1810   definition "K x _ = x"
  1811 
  1812   inductive conj for A B
  1813   where "A ==> B ==> conj A B"
  1814 
  1815 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1816 the current context.  Print mode "no_abbrevs" prevents inversion of
  1817 abbreviations on output.
  1818 
  1819 * Isar/locales: improved parameter handling: use of locales "var" and
  1820 "struct" no longer necessary; - parameter renamings are no longer
  1821 required to be injective.  For example, this allows to define
  1822 endomorphisms as locale endom = homom mult mult h.
  1823 
  1824 * Isar/locales: changed the way locales with predicates are defined.
  1825 Instead of accumulating the specification, the imported expression is
  1826 now an interpretation.  INCOMPATIBILITY: different normal form of
  1827 locale expressions.  In particular, in interpretations of locales with
  1828 predicates, goals repesenting already interpreted fragments are not
  1829 removed automatically.  Use methods `intro_locales' and
  1830 `unfold_locales'; see below.
  1831 
  1832 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1833 provide backward reasoning on locales predicates.  The methods are
  1834 aware of interpretations and discharge corresponding goals.
  1835 `intro_locales' is less aggressive then `unfold_locales' and does not
  1836 unfold predicates to assumptions.
  1837 
  1838 * Isar/locales: the order in which locale fragments are accumulated
  1839 has changed.  This enables to override declarations from fragments due
  1840 to interpretations -- for example, unwanted simp rules.
  1841 
  1842 * Isar/locales: interpretation in theories and proof contexts has been
  1843 extended.  One may now specify (and prove) equations, which are
  1844 unfolded in interpreted theorems.  This is useful for replacing
  1845 defined concepts (constants depending on locale parameters) by
  1846 concepts already existing in the target context.  Example:
  1847 
  1848   interpretation partial_order ["op <= :: [int, int] => bool"]
  1849     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1850 
  1851 Typically, the constant `partial_order.less' is created by a
  1852 definition specification element in the context of locale
  1853 partial_order.
  1854 
  1855 * Method "induct": improved internal context management to support
  1856 local fixes and defines on-the-fly. Thus explicit meta-level
  1857 connectives !!  and ==> are rarely required anymore in inductive goals
  1858 (using object-logic connectives for this purpose has been long
  1859 obsolete anyway). Common proof patterns are explained in
  1860 src/HOL/Induct/Common_Patterns.thy, see also
  1861 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1862 examples.
  1863 
  1864 * Method "induct": improved handling of simultaneous goals. Instead of
  1865 introducing object-level conjunction, the statement is now split into
  1866 several conclusions, while the corresponding symbolic cases are nested
  1867 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1868 see src/HOL/Induct/Common_Patterns.thy, for example.
  1869 
  1870 * Method "induct": mutual induction rules are now specified as a list
  1871 of rule sharing the same induction cases. HOL packages usually provide
  1872 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1873 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1874 mutual induction rules differently, i.e. like this:
  1875 
  1876   (induct rule: foo_bar.inducts)
  1877   (induct set: foo bar)
  1878   (induct pred: foo bar)
  1879   (induct type: foo bar)
  1880 
  1881 The ML function ProjectRule.projections turns old-style rules into the
  1882 new format.
  1883 
  1884 * Method "coinduct": dual of induction, see
  1885 src/HOL/Library/Coinductive_List.thy for various examples.
  1886 
  1887 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1888 considered a legacy feature.
  1889 
  1890 * Attribute "symmetric" produces result with standardized schematic
  1891 variables (index 0).  Potential INCOMPATIBILITY.
  1892 
  1893 * Simplifier: by default the simplifier trace only shows top level
  1894 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1895 default. Thus there is less danger of being flooded by the trace. The
  1896 trace indicates where parts have been suppressed.
  1897   
  1898 * Provers/classical: removed obsolete classical version of elim_format
  1899 attribute; classical elim/dest rules are now treated uniformly when
  1900 manipulating the claset.
  1901 
  1902 * Provers/classical: stricter checks to ensure that supplied intro,
  1903 dest and elim rules are well-formed; dest and elim rules must have at
  1904 least one premise.
  1905 
  1906 * Provers/classical: attributes dest/elim/intro take an optional
  1907 weight argument for the rule (just as the Pure versions).  Weights are
  1908 ignored by automated tools, but determine the search order of single
  1909 rule steps.
  1910 
  1911 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1912 where the body does not mention the bound variable.  Note that dummy
  1913 patterns implicitly depend on their context of bounds, which makes
  1914 "{_. _}" match any set comprehension as expected.  Potential
  1915 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1916 constant "_idtdummy" in the binding position.
  1917 
  1918 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1919 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1920 for example "A -> B" => "Pi A (%_. B)".
  1921 
  1922 * Pure: 'class_deps' command visualizes the subclass relation, using
  1923 the graph browser tool.
  1924 
  1925 * Pure: 'print_theory' now suppresses certain internal declarations by
  1926 default; use '!' option for full details.
  1927 
  1928 
  1929 *** HOL ***
  1930 
  1931 * Method "metis" proves goals by applying the Metis general-purpose
  1932 resolution prover (see also http://gilith.com/software/metis/).
  1933 Examples are in the directory MetisExamples.  WARNING: the
  1934 Isabelle/HOL-Metis integration does not yet work properly with
  1935 multi-threading.
  1936   
  1937 * Command 'sledgehammer' invokes external automatic theorem provers as
  1938 background processes.  It generates calls to the "metis" method if
  1939 successful. These can be pasted into the proof.  Users do not have to
  1940 wait for the automatic provers to return.  WARNING: does not really
  1941 work with multi-threading.
  1942 
  1943 * New "auto_quickcheck" feature tests outermost goal statements for
  1944 potential counter-examples.  Controlled by ML references
  1945 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1946 5000 milliseconds).  Fails silently if statements is outside of
  1947 executable fragment, or any other codgenerator problem occurs.
  1948 
  1949 * New constant "undefined" with axiom "undefined x = undefined".
  1950 
  1951 * Added class "HOL.eq", allowing for code generation with polymorphic
  1952 equality.
  1953 
  1954 * Some renaming of class constants due to canonical name prefixing in
  1955 the new 'class' package:
  1956 
  1957     HOL.abs ~> HOL.abs_class.abs
  1958     HOL.divide ~> HOL.divide_class.divide
  1959     0 ~> HOL.zero_class.zero
  1960     1 ~> HOL.one_class.one
  1961     op + ~> HOL.plus_class.plus
  1962     op - ~> HOL.minus_class.minus
  1963     uminus ~> HOL.minus_class.uminus
  1964     op * ~> HOL.times_class.times
  1965     op < ~> HOL.ord_class.less
  1966     op <= > HOL.ord_class.less_eq
  1967     Nat.power ~> Power.power_class.power
  1968     Nat.size ~> Nat.size_class.size
  1969     Numeral.number_of ~> Numeral.number_class.number_of
  1970     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1971     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1972     Orderings.min ~> Orderings.ord_class.min
  1973     Orderings.max ~> Orderings.ord_class.max
  1974     Divides.op div ~> Divides.div_class.div
  1975     Divides.op mod ~> Divides.div_class.mod
  1976     Divides.op dvd ~> Divides.div_class.dvd
  1977 
  1978 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1979 
  1980 a) User-defined constants using any of the names "plus", "minus",
  1981 "times", "less" or "less_eq". The standard syntax translations for
  1982 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1983 names.
  1984 
  1985 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1986 INCOMPATIBILITY: use more specific names.
  1987 
  1988 c) Permutative equations (e.g. "a + b = b + a")
  1989 Since the change of names also changes the order of terms, permutative
  1990 rewrite rules may get applied in a different order. Experience shows
  1991 that this is rarely the case (only two adaptions in the whole Isabelle
  1992 distribution).  INCOMPATIBILITY: rewrite proofs
  1993 
  1994 d) ML code directly refering to constant names
  1995 This in general only affects hand-written proof tactics, simprocs and
  1996 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1997 Consider using @{const_name} antiquotation.
  1998 
  1999 * New class "default" with associated constant "default".
  2000 
  2001 * Function "sgn" is now overloaded and available on int, real, complex
  2002 (and other numeric types), using class "sgn".  Two possible defs of
  2003 sgn are given as equational assumptions in the classes sgn_if and
  2004 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2005 INCOMPATIBILITY.
  2006 
  2007 * Locale "partial_order" now unified with class "order" (cf. theory
  2008 Orderings), added parameter "less".  INCOMPATIBILITY.
  2009 
  2010 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2011 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2012 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2013 
  2014 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2015 changed order of proof goals in instance proofs.
  2016 
  2017 * The transitivity reasoner for partial and linear orders is set up
  2018 for classes "order" and "linorder".  Instances of the reasoner are available
  2019 in all contexts importing or interpreting the corresponding locales.
  2020 Method "order" invokes the reasoner separately; the reasoner
  2021 is also integrated with the Simplifier as a solver.  Diagnostic
  2022 command 'print_orders' shows the available instances of the reasoner
  2023 in the current context.
  2024 
  2025 * Localized monotonicity predicate in theory "Orderings"; integrated
  2026 lemmas max_of_mono and min_of_mono with this predicate.
  2027 INCOMPATIBILITY.
  2028 
  2029 * Formulation of theorem "dense" changed slightly due to integration
  2030 with new class dense_linear_order.
  2031 
  2032 * Uniform lattice theory development in HOL.
  2033 
  2034     constants "meet" and "join" now named "inf" and "sup"
  2035     constant "Meet" now named "Inf"
  2036 
  2037     classes "meet_semilorder" and "join_semilorder" now named
  2038       "lower_semilattice" and "upper_semilattice"
  2039     class "lorder" now named "lattice"
  2040     class "comp_lat" now named "complete_lattice"
  2041 
  2042     Instantiation of lattice classes allows explicit definitions
  2043     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2044 
  2045   INCOMPATIBILITY.  Theorem renames:
  2046 
  2047     meet_left_le            ~> inf_le1
  2048     meet_right_le           ~> inf_le2
  2049     join_left_le            ~> sup_ge1
  2050     join_right_le           ~> sup_ge2
  2051     meet_join_le            ~> inf_sup_ord
  2052     le_meetI                ~> le_infI
  2053     join_leI                ~> le_supI
  2054     le_meet                 ~> le_inf_iff
  2055     le_join                 ~> ge_sup_conv
  2056     meet_idempotent         ~> inf_idem
  2057     join_idempotent         ~> sup_idem
  2058     meet_comm               ~> inf_commute
  2059     join_comm               ~> sup_commute
  2060     meet_leI1               ~> le_infI1
  2061     meet_leI2               ~> le_infI2
  2062     le_joinI1               ~> le_supI1
  2063     le_joinI2               ~> le_supI2
  2064     meet_assoc              ~> inf_assoc
  2065     join_assoc              ~> sup_assoc
  2066     meet_left_comm          ~> inf_left_commute
  2067     meet_left_idempotent    ~> inf_left_idem
  2068     join_left_comm          ~> sup_left_commute
  2069     join_left_idempotent    ~> sup_left_idem
  2070     meet_aci                ~> inf_aci
  2071     join_aci                ~> sup_aci
  2072     le_def_meet             ~> le_iff_inf
  2073     le_def_join             ~> le_iff_sup
  2074     join_absorp2            ~> sup_absorb2
  2075     join_absorp1            ~> sup_absorb1
  2076     meet_absorp1            ~> inf_absorb1
  2077     meet_absorp2            ~> inf_absorb2
  2078     meet_join_absorp        ~> inf_sup_absorb
  2079     join_meet_absorp        ~> sup_inf_absorb
  2080     distrib_join_le         ~> distrib_sup_le
  2081     distrib_meet_le         ~> distrib_inf_le
  2082 
  2083     add_meet_distrib_left   ~> add_inf_distrib_left
  2084     add_join_distrib_left   ~> add_sup_distrib_left
  2085     is_join_neg_meet        ~> is_join_neg_inf
  2086     is_meet_neg_join        ~> is_meet_neg_sup
  2087     add_meet_distrib_right  ~> add_inf_distrib_right
  2088     add_join_distrib_right  ~> add_sup_distrib_right
  2089     add_meet_join_distribs  ~> add_sup_inf_distribs
  2090     join_eq_neg_meet        ~> sup_eq_neg_inf
  2091     meet_eq_neg_join        ~> inf_eq_neg_sup
  2092     add_eq_meet_join        ~> add_eq_inf_sup
  2093     meet_0_imp_0            ~> inf_0_imp_0
  2094     join_0_imp_0            ~> sup_0_imp_0
  2095     meet_0_eq_0             ~> inf_0_eq_0
  2096     join_0_eq_0             ~> sup_0_eq_0
  2097     neg_meet_eq_join        ~> neg_inf_eq_sup
  2098     neg_join_eq_meet        ~> neg_sup_eq_inf
  2099     join_eq_if              ~> sup_eq_if
  2100 
  2101     mono_meet               ~> mono_inf
  2102     mono_join               ~> mono_sup
  2103     meet_bool_eq            ~> inf_bool_eq
  2104     join_bool_eq            ~> sup_bool_eq
  2105     meet_fun_eq             ~> inf_fun_eq
  2106     join_fun_eq             ~> sup_fun_eq
  2107     meet_set_eq             ~> inf_set_eq
  2108     join_set_eq             ~> sup_set_eq
  2109     meet1_iff               ~> inf1_iff
  2110     meet2_iff               ~> inf2_iff
  2111     meet1I                  ~> inf1I
  2112     meet2I                  ~> inf2I
  2113     meet1D1                 ~> inf1D1
  2114     meet2D1                 ~> inf2D1
  2115     meet1D2                 ~> inf1D2
  2116     meet2D2                 ~> inf2D2
  2117     meet1E                  ~> inf1E
  2118     meet2E                  ~> inf2E
  2119     join1_iff               ~> sup1_iff
  2120     join2_iff               ~> sup2_iff
  2121     join1I1                 ~> sup1I1
  2122     join2I1                 ~> sup2I1
  2123     join1I1                 ~> sup1I1
  2124     join2I2                 ~> sup1I2
  2125     join1CI                 ~> sup1CI
  2126     join2CI                 ~> sup2CI
  2127     join1E                  ~> sup1E
  2128     join2E                  ~> sup2E
  2129 
  2130     is_meet_Meet            ~> is_meet_Inf
  2131     Meet_bool_def           ~> Inf_bool_def
  2132     Meet_fun_def            ~> Inf_fun_def
  2133     Meet_greatest           ~> Inf_greatest
  2134     Meet_lower              ~> Inf_lower
  2135     Meet_set_def            ~> Inf_set_def
  2136 
  2137     Sup_def                 ~> Sup_Inf
  2138     Sup_bool_eq             ~> Sup_bool_def
  2139     Sup_fun_eq              ~> Sup_fun_def
  2140     Sup_set_eq              ~> Sup_set_def
  2141 
  2142     listsp_meetI            ~> listsp_infI
  2143     listsp_meet_eq          ~> listsp_inf_eq
  2144 
  2145     meet_min                ~> inf_min
  2146     join_max                ~> sup_max
  2147 
  2148 * Added syntactic class "size"; overloaded constant "size" now has
  2149 type "'a::size ==> bool"
  2150 
  2151 * Internal reorganisation of `size' of datatypes: size theorems
  2152 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2153 simplification rules by default!); theorems "prod.size" now named
  2154 "*.size".
  2155 
  2156 * Class "div" now inherits from class "times" rather than "type".
  2157 INCOMPATIBILITY.
  2158 
  2159 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2160 Linorder etc.  have disappeared; operations defined in terms of
  2161 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2162 
  2163 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2164 
  2165 * HOL-Word: New extensive library and type for generic, fixed size
  2166 machine words, with arithemtic, bit-wise, shifting and rotating
  2167 operations, reflection into int, nat, and bool lists, automation for
  2168 linear arithmetic (by automatic reflection into nat or int), including
  2169 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2170 arithmetic type classes, supporting automatic simplification of
  2171 numerals on all operations.
  2172 
  2173 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2174 
  2175 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2176 
  2177 * Code generator library theories:
  2178   - Code_Integer represents HOL integers by big integer literals in target
  2179     languages.
  2180   - Code_Char represents HOL characters by character literals in target
  2181     languages.
  2182   - Code_Char_chr like Code_Char, but also offers treatment of character
  2183     codes; includes Code_Integer.
  2184   - Executable_Set allows to generate code for finite sets using lists.
  2185   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2186     denominator).
  2187   - Executable_Real implements a subset of real numbers, namly those
  2188     representable by rational numbers.
  2189   - Efficient_Nat implements natural numbers by integers, which in general will
  2190     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2191     includes Code_Integer.
  2192   - Code_Index provides an additional datatype index which is mapped to
  2193     target-language built-in integers.
  2194   - Code_Message provides an additional datatype message_string which is isomorphic to
  2195     strings; messages are mapped to target-language strings.
  2196 
  2197 * New package for inductive predicates
  2198 
  2199   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2200 
  2201     inductive
  2202       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2203       for z_1 :: U_1 and ... and z_n :: U_m
  2204     where
  2205       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2206     | ...
  2207 
  2208   with full support for type-inference, rather than
  2209 
  2210     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2211 
  2212     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2213     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2214 
  2215     inductive "s z_1 ... z_m"
  2216     intros
  2217       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2218       ...
  2219 
  2220   For backward compatibility, there is a wrapper allowing inductive
  2221   sets to be defined with the new package via
  2222 
  2223     inductive_set
  2224       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2225       for z_1 :: U_1 and ... and z_n :: U_m
  2226     where
  2227       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2228     | ...
  2229 
  2230   or
  2231 
  2232     inductive_set
  2233       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2234       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2235       for z_1 :: U_1 and ... and z_n :: U_m
  2236     where
  2237       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2238     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2239     | ...
  2240 
  2241   if the additional syntax "p ..." is required.
  2242 
  2243   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2244   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2245 
  2246   INCOMPATIBILITIES:
  2247 
  2248   - Since declaration and definition of inductive sets or predicates
  2249     is no longer separated, abbreviations involving the newly
  2250     introduced sets or predicates must be specified together with the
  2251     introduction rules after the 'where' keyword (see above), rather
  2252     than before the actual inductive definition.
  2253 
  2254   - The variables in induction and elimination rules are now
  2255     quantified in the order of their occurrence in the introduction
  2256     rules, rather than in alphabetical order. Since this may break
  2257     some proofs, these proofs either have to be repaired, e.g. by
  2258     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2259     statements of the form
  2260 
  2261       case (rule_i a_i_1 ... a_i_{k_i})
  2262 
  2263     or the old order of quantification has to be restored by explicitly adding
  2264     meta-level quantifiers in the introduction rules, i.e.
  2265 
  2266       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2267 
  2268   - The format of the elimination rules is now
  2269 
  2270       p z_1 ... z_m x_1 ... x_n ==>
  2271         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2272         ==> ... ==> P
  2273 
  2274     for predicates and
  2275 
  2276       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2277         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2278         ==> ... ==> P
  2279 
  2280     for sets rather than
  2281 
  2282       x : s z_1 ... z_m ==>
  2283         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2284         ==> ... ==> P
  2285 
  2286     This may require terms in goals to be expanded to n-tuples
  2287     (e.g. using case_tac or simplification with the split_paired_all
  2288     rule) before the above elimination rule is applicable.
  2289 
  2290   - The elimination or case analysis rules for (mutually) inductive
  2291     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2292     list of rules "p_1_..._p_k.elims" is no longer available.
  2293 
  2294 * New package "function"/"fun" for general recursive functions,
  2295 supporting mutual and nested recursion, definitions in local contexts,
  2296 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2297 for small examples, and the separate tutorial on the function
  2298 package. The old recdef "package" is still available as before, but
  2299 users are encouraged to use the new package.
  2300 
  2301 * Method "lexicographic_order" automatically synthesizes termination
  2302 relations as lexicographic combinations of size measures. 
  2303 
  2304 * Case-expressions allow arbitrary constructor-patterns (including
  2305 "_") and take their order into account, like in functional
  2306 programming.  Internally, this is translated into nested
  2307 case-expressions; missing cases are added and mapped to the predefined
  2308 constant "undefined". In complicated cases printing may no longer show
  2309 the original input but the internal form. Lambda-abstractions allow
  2310 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2311 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2312 variable.
  2313 
  2314 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2315 is an abbreviation for "of_nat :: nat => int". The simplification
  2316 rules for "of_nat" have been changed to work like "int" did
  2317 previously.  Potential INCOMPATIBILITY:
  2318   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2319   - of_nat_diff and of_nat_mult are no longer default simp rules
  2320 
  2321 * Method "algebra" solves polynomial equations over (semi)rings using
  2322 Groebner bases. The (semi)ring structure is defined by locales and the
  2323 tool setup depends on that generic context. Installing the method for
  2324 a specific type involves instantiating the locale and possibly adding
  2325 declarations for computation on the coefficients.  The method is
  2326 already instantiated for natural numbers and for the axiomatic class
  2327 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2328 CALCULEMUS 2007 for the general principles underlying this
  2329 architecture of context-aware proof-tools.
  2330 
  2331 * Method "ferrack" implements quantifier elimination over
  2332 special-purpose dense linear orders using locales (analogous to
  2333 "algebra"). The method is already installed for class
  2334 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2335 rat, etc.
  2336 
  2337 * Former constant "List.op @" now named "List.append".  Use ML
  2338 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2339 circumvent possible incompatibilities when working on ML level.
  2340 
  2341 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2342 
  2343 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2344 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2345 
  2346 * New syntax for Haskell-like list comprehension (input only), eg.
  2347 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2348 
  2349 * The special syntax for function "filter" has changed from [x :
  2350 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2351 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2352 
  2353 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2354 defined on nat only, as an abbreviation for [a..<Suc b]
  2355 INCOMPATIBILITY.
  2356 
  2357 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2358 
  2359 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2360 
  2361 * New lemma collection field_simps (an extension of ring_simps) for
  2362 manipulating (in)equations involving division. Multiplies with all
  2363 denominators that can be proved to be non-zero (in equations) or
  2364 positive/negative (in inequations).
  2365 
  2366 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2367 have been improved and renamed to ring_simps, group_simps and
  2368 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2369 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2370 
  2371 * Theory Library/Commutative_Ring: switched from recdef to function
  2372 package; constants add, mul, pow now curried.  Infix syntax for
  2373 algebraic operations.
  2374 
  2375 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2376 INCOMPATIBILITY.
  2377 
  2378 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2379 INCOMPATIBILITY.
  2380 
  2381 * HOL/records: generalised field-update to take a function on the
  2382 field rather than the new value: r(|A := x|) is translated to A_update
  2383 (K x) r The K-combinator that is internally used is called K_record.
  2384 INCOMPATIBILITY: Usage of the plain update functions has to be
  2385 adapted.
  2386  
  2387 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2388 * x = 0, which are required for a semiring.  Richer structures do not
  2389 inherit from semiring_0 anymore, because this property is a theorem
  2390 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2391 there is more to prove, but this is mostly trivial.
  2392 
  2393 * Class "recpower" is generalized to arbitrary monoids, not just
  2394 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2395 commutativity or semiring properties additionally.
  2396 
  2397 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2398 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2399 better use 'abbreviation'.
  2400 
  2401 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2402 
  2403 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2404 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2405 significant changes for setting up numeral syntax for types:
  2406   - New constants Numeral.pred and Numeral.succ instead
  2407       of former Numeral.bin_pred and Numeral.bin_succ.
  2408   - Use integer operations instead of bin_add, bin_mult and so on.
  2409   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2410   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2411 
  2412 See src/HOL/Integ/IntArith.thy for an example setup.
  2413 
  2414 * Command 'normal_form' computes the normal form of a term that may
  2415 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2416 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2417 heavy-duty computations because the functions are compiled to ML
  2418 first.  Correspondingly, a method "normalization" is provided.  See
  2419 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2420 
  2421 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2422 25 like -->); output depends on the "iff" print_mode, the default is
  2423 "A = B" (with priority 50).
  2424 
  2425 * Relations less (<) and less_eq (<=) are also available on type bool.
  2426 Modified syntax to disallow nesting without explicit parentheses,
  2427 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2428 INCOMPATIBILITY.
  2429 
  2430 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2431 
  2432 * Relation composition operator "op O" now has precedence 75 and binds
  2433 stronger than union and intersection. INCOMPATIBILITY.
  2434 
  2435 * The old set interval syntax "{m..n(}" (and relatives) has been
  2436 removed.  Use "{m..<n}" (and relatives) instead.
  2437 
  2438 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2439 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2440 ``declare [[simproc del: neq]]''.
  2441 
  2442 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2443 True/False.
  2444 
  2445 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2446 
  2447 * Theorem setsum_mult renamed to setsum_right_distrib.
  2448 
  2449 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2450 ``rule'' method.
  2451 
  2452 * Reimplemented methods "sat" and "satx", with several improvements:
  2453 goals no longer need to be stated as "<prems> ==> False", equivalences
  2454 (i.e. "=" on type bool) are handled, variable names of the form
  2455 "lit_<n>" are no longer reserved, significant speedup.
  2456 
  2457 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2458 zChaff is still supported as well.
  2459 
  2460 * 'inductive' and 'datatype': provide projections of mutual rules,
  2461 bundled as foo_bar.inducts;
  2462 
  2463 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2464 Library.
  2465 
  2466 * Library: moved theory Accessible_Part to main HOL.
  2467 
  2468 * Library: added theory Coinductive_List of potentially infinite lists
  2469 as greatest fixed-point.
  2470 
  2471 * Library: added theory AssocList which implements (finite) maps as
  2472 association lists.
  2473 
  2474 * Method "evaluation" solves goals (i.e. a boolean expression)
  2475 efficiently by compiling it to ML.  The goal is "proved" (via an
  2476 oracle) if it evaluates to True.
  2477 
  2478 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2479 also when invoked by the simplifier.  This results in the Simplifier
  2480 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2481 Configuration option fast_arith_split_limit=0 recovers the old
  2482 behavior.
  2483 
  2484 * Support for hex (0x20) and binary (0b1001) numerals.
  2485 
  2486 * New method: reify eqs (t), where eqs are equations for an
  2487 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2488 parameter, computes a term s::'b and a list xs::'a list and proves the
  2489 theorem I xs s = t. This is also known as reification or quoting. The
  2490 resulting theorem is applied to the subgoal to substitute t with I xs
  2491 s.  If t is omitted, the subgoal itself is reified.
  2492 
  2493 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2494 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2495 where f is supposed to be a computable function (in the sense of code
  2496 generattion). The method uses reify to compute s and xs as above then
  2497 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2498 r and finally gets the theorem t = r, which is again applied to the
  2499 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2500 
  2501 * Reflection: Automatic reification now handels binding, an example is
  2502 available in src/HOL/ex/ReflectionEx.thy
  2503 
  2504 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2505 command 'statespace' that is similar to 'record', but introduces an
  2506 abstract specification based on the locale infrastructure instead of
  2507 HOL types.  This leads to extra flexibility in composing state spaces,
  2508 in particular multiple inheritance and renaming of components.
  2509 
  2510 
  2511 *** HOL-Complex ***
  2512 
  2513 * Hyperreal: Functions root and sqrt are now defined on negative real
  2514 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2515 Nonnegativity side conditions have been removed from many lemmas, so
  2516 that more subgoals may now be solved by simplification; potential
  2517 INCOMPATIBILITY.
  2518 
  2519 * Real: new type classes formalize real normed vector spaces and
  2520 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2521 and norm :: 'a => real.
  2522 
  2523 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2524 reals into other types. The overloaded constant Reals :: 'a set is now
  2525 defined as range of_real; potential INCOMPATIBILITY.
  2526 
  2527 * Real: proper support for ML code generation, including 'quickcheck'.
  2528 Reals are implemented as arbitrary precision rationals.
  2529 
  2530 * Hyperreal: Several constants that previously worked only for the
  2531 reals have been generalized, so they now work over arbitrary vector
  2532 spaces. Type annotations may need to be added in some cases; potential
  2533 INCOMPATIBILITY.
  2534 
  2535   Infinitesimal  :: ('a::real_normed_vector) star set
  2536   HFinite        :: ('a::real_normed_vector) star set
  2537   HInfinite      :: ('a::real_normed_vector) star set
  2538   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2539   monad          :: ('a::real_normed_vector) star => 'a star set
  2540   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2541   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2542   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2543   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2544   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2545   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2546   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2547   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2548   sgn            :: 'a::real_normed_vector => 'a
  2549   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2550 
  2551 * Complex: Some complex-specific constants are now abbreviations for
  2552 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2553 hnorm.  Other constants have been entirely removed in favor of the
  2554 polymorphic versions (INCOMPATIBILITY):
  2555 
  2556   approx        <-- capprox
  2557   HFinite       <-- CFinite
  2558   HInfinite     <-- CInfinite
  2559   Infinitesimal <-- CInfinitesimal
  2560   monad         <-- cmonad
  2561   galaxy        <-- cgalaxy
  2562   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2563   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2564   (ns)deriv     <-- (ns)cderiv
  2565 
  2566 
  2567 *** HOL-Algebra ***
  2568 
  2569 * Formalisation of ideals and the quotient construction over rings.
  2570 
  2571 * Order and lattice theory no longer based on records.
  2572 INCOMPATIBILITY.
  2573 
  2574 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2575 greatest_closed.  INCOMPATIBILITY.
  2576 
  2577 * Method algebra is now set up via an attribute.  For examples see
  2578 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2579 of algebraic structures.
  2580 
  2581 * Renamed theory CRing to Ring.
  2582 
  2583 
  2584 *** HOL-Nominal ***
  2585 
  2586 * Substantial, yet incomplete support for nominal datatypes (binding
  2587 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2588 src/HOL/Nominal/Examples.  Prospective users should consult
  2589 http://isabelle.in.tum.de/nominal/
  2590 
  2591 
  2592 *** ML ***
  2593 
  2594 * ML basics: just one true type int, which coincides with IntInf.int
  2595 (even on SML/NJ).
  2596 
  2597 * ML within Isar: antiquotations allow to embed statically-checked
  2598 formal entities in the source, referring to the context available at
  2599 compile-time.  For example:
  2600 
  2601 ML {* @{sort "{zero,one}"} *}
  2602 ML {* @{typ "'a => 'b"} *}
  2603 ML {* @{term "%x. x"} *}
  2604 ML {* @{prop "x == y"} *}
  2605 ML {* @{ctyp "'a => 'b"} *}
  2606 ML {* @{cterm "%x. x"} *}
  2607 ML {* @{cprop "x == y"} *}
  2608 ML {* @{thm asm_rl} *}
  2609 ML {* @{thms asm_rl} *}
  2610 ML {* @{type_name c} *}
  2611 ML {* @{type_syntax c} *}
  2612 ML {* @{const_name c} *}
  2613 ML {* @{const_syntax c} *}
  2614 ML {* @{context} *}
  2615 ML {* @{theory} *}
  2616 ML {* @{theory Pure} *}
  2617 ML {* @{theory_ref} *}
  2618 ML {* @{theory_ref Pure} *}
  2619 ML {* @{simpset} *}
  2620 ML {* @{claset} *}
  2621 ML {* @{clasimpset} *}
  2622 
  2623 The same works for sources being ``used'' within an Isar context.
  2624 
  2625 * ML in Isar: improved error reporting; extra verbosity with
  2626 ML_Context.trace enabled.
  2627 
  2628 * Pure/General/table.ML: the join operations now works via exceptions
  2629 DUP/SAME instead of type option. This is simpler in simple cases, and
  2630 admits slightly more efficient complex applications.
  2631 
  2632 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2633 use Context.generic instead of just theory.
  2634 
  2635 * Pure: datatype Context.generic joins theory/Proof.context and
  2636 provides some facilities for code that works in either kind of
  2637 context, notably GenericDataFun for uniform theory and proof data.
  2638 
  2639 * Pure: simplified internal attribute type, which is now always
  2640 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2641 local (Proof.context) attributes have been discontinued, while
  2642 minimizing code duplication. Thm.rule_attribute and
  2643 Thm.declaration_attribute build canonical attributes; see also structure
  2644 Context for further operations on Context.generic, notably
  2645 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2646 declarations and definitions.
  2647 
  2648 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2649 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2650 init only required for impure data. INCOMPATIBILITY: empty really need
  2651 to be empty (no dependencies on theory content!)
  2652 
  2653 * Pure/kernel: consts certification ignores sort constraints given in
  2654 signature declarations. (This information is not relevant to the
  2655 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2656 potential INCOMPATIBILITY.
  2657 
  2658 * Pure: axiomatic type classes are now purely definitional, with
  2659 explicit proofs of class axioms and super class relations performed
  2660 internally. See Pure/axclass.ML for the main internal interfaces --
  2661 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2662 AxClass.axiomatize_class/classrel/arity supersede
  2663 Sign.add_classes/classrel/arities.
  2664 
  2665 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2666 global/local versions on theory vs. Proof.context have been
  2667 discontinued; Attrib.syntax and Method.syntax have been adapted
  2668 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2669 attributes, methods, etc.
  2670 
  2671 * Pure: several functions of signature "... -> theory -> theory * ..."
  2672 have been reoriented to "... -> theory -> ... * theory" in order to
  2673 allow natural usage in combination with the ||>, ||>>, |-> and
  2674 fold_map combinators.
  2675 
  2676 * Pure: official theorem names (closed derivations) and additional
  2677 comments (tags) are now strictly separate.  Name hints -- which are
  2678 maintained as tags -- may be attached any time without affecting the
  2679 derivation.
  2680 
  2681 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2682 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2683 achieve the old behaviour.
  2684 
  2685 * Pure: the "Goal" constant is now called "prop", supporting a
  2686 slightly more general idea of ``protecting'' meta-level rule
  2687 statements.
  2688 
  2689 * Pure: Logic.(un)varify only works in a global context, which is now
  2690 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2691 Logic.legacy_(un)varify as temporary workaround.
  2692 
  2693 * Pure: structure Name provides scalable operations for generating
  2694 internal variable names, notably Name.variants etc.  This replaces
  2695 some popular functions from term.ML:
  2696 
  2697   Term.variant		->  Name.variant
  2698   Term.variantlist	->  Name.variant_list
  2699   Term.invent_names	->  Name.invent_list
  2700 
  2701 Note that low-level renaming rarely occurs in new code -- operations
  2702 from structure Variable are used instead (see below).
  2703 
  2704 * Pure: structure Variable provides fundamental operations for proper
  2705 treatment of fixed/schematic variables in a context.  For example,
  2706 Variable.import introduces fixes for schematics of given facts and
  2707 Variable.export reverses the effect (up to renaming) -- this replaces
  2708 various freeze_thaw operations.
  2709 
  2710 * Pure: structure Goal provides simple interfaces for
  2711 init/conclude/finish and tactical prove operations (replacing former
  2712 Tactic.prove).  Goal.prove is the canonical way to prove results
  2713 within a given context; Goal.prove_global is a degraded version for
  2714 theory level goals, including a global Drule.standard.  Note that
  2715 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2716 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2717 in a locale context).
  2718 
  2719 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2720 and type checking (Syntax.check_term etc.), with common combinations
  2721 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2722 which are considered legacy and await removal.
  2723 
  2724 * Pure/Syntax: generic interfaces for type unchecking
  2725 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2726 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2727 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2728 available for convenience, but refer to the very same operations using
  2729 a mere theory instead of a full context.
  2730 
  2731 * Isar: simplified treatment of user-level errors, using exception
  2732 ERROR of string uniformly.  Function error now merely raises ERROR,
  2733 without any side effect on output channels.  The Isar toplevel takes
  2734 care of proper display of ERROR exceptions.  ML code may use plain
  2735 handle/can/try; cat_error may be used to concatenate errors like this:
  2736 
  2737   ... handle ERROR msg => cat_error msg "..."
  2738 
  2739 Toplevel ML code (run directly or through the Isar toplevel) may be
  2740 embedded into the Isar toplevel with exception display/debug like
  2741 this:
  2742 
  2743   Isar.toplevel (fn () => ...)
  2744 
  2745 INCOMPATIBILITY, removed special transform_error facilities, removed
  2746 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2747 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2748 -- use plain ERROR instead.
  2749 
  2750 * Isar: theory setup now has type (theory -> theory), instead of a
  2751 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2752 
  2753 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2754 ProofContext.debug/verbose flags.
  2755 
  2756 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2757 theory before entering a proof state.  Transactions now always see a
  2758 quasi-functional intermediate checkpoint, both in interactive and
  2759 batch mode.
  2760 
  2761 * Isar: simplified interfaces for outer syntax.  Renamed
  2762 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2763 OuterSyntax.add_parsers -- this functionality is now included in
  2764 OuterSyntax.command etc.  INCOMPATIBILITY.
  2765 
  2766 * Simplifier: the simpset of a running simplification process now
  2767 contains a proof context (cf. Simplifier.the_context), which is the
  2768 very context that the initial simpset has been retrieved from (by
  2769 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2770 (solver, looper etc.) may depend on arbitrary proof data.
  2771 
  2772 * Simplifier.inherit_context inherits the proof context (plus the
  2773 local bounds) of the current simplification process; any simproc
  2774 etc. that calls the Simplifier recursively should do this!  Removed
  2775 former Simplifier.inherit_bounds, which is already included here --
  2776 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2777 specify an explicit context using Simplifier.context/theory_context.
  2778 
  2779 * Simplifier/Classical Reasoner: more abstract interfaces
  2780 change_simpset/claset for modifying the simpset/claset reference of a
  2781 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2782 INCOMPATIBILITY.
  2783 
  2784 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2785 "Trueprop" etc.
  2786 
  2787 
  2788 *** System ***
  2789 
  2790 * settings: the default heap location within ISABELLE_HOME_USER now
  2791 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2792 Isabelle installations.
  2793 
  2794 * isabelle-process: option -S (secure mode) disables some critical
  2795 operations, notably runtime compilation and evaluation of ML source
  2796 code.
  2797 
  2798 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2799 
  2800 * Support for parallel execution, using native multicore support of
  2801 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2802 independent theories, according to the given theory header
  2803 specifications. The maximum number of worker threads is specified via
  2804 usedir option -M or the "max-threads" setting in Proof General. A
  2805 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2806 to 6 on a 8-core machine.  User-code needs to observe certain
  2807 guidelines for thread-safe programming, see appendix A in the Isar
  2808 Implementation manual.
  2809 
  2810 
  2811 
  2812 New in Isabelle2005 (October 2005)
  2813 ----------------------------------
  2814 
  2815 *** General ***
  2816 
  2817 * Theory headers: the new header syntax for Isar theories is
  2818 
  2819   theory <name>
  2820   imports <theory1> ... <theoryN>
  2821   uses <file1> ... <fileM>
  2822   begin
  2823 
  2824 where the 'uses' part is optional.  The previous syntax
  2825 
  2826   theory <name> = <theory1> + ... + <theoryN>:
  2827 
  2828 will disappear in the next release.  Use isatool fixheaders to convert
  2829 existing theory files.  Note that there is no change in ancient
  2830 non-Isar theories now, but these will disappear soon.
  2831 
  2832 * Theory loader: parent theories can now also be referred to via
  2833 relative and absolute paths.
  2834 
  2835 * Command 'find_theorems' searches for a list of criteria instead of a
  2836 list of constants. Known criteria are: intro, elim, dest, name:string,
  2837 simp:term, and any term. Criteria can be preceded by '-' to select
  2838 theorems that do not match. Intro, elim, dest select theorems that
  2839 match the current goal, name:s selects theorems whose fully qualified
  2840 name contain s, and simp:term selects all simplification rules whose
  2841 lhs match term.  Any other term is interpreted as pattern and selects
  2842 all theorems matching the pattern. Available in ProofGeneral under
  2843 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2844 
  2845   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2846 
  2847 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2848 matching the current goal as introduction rule and not having "HOL."
  2849 in their name (i.e. not being defined in theory HOL).
  2850 
  2851 * Command 'thms_containing' has been discontinued in favour of
  2852 'find_theorems'; INCOMPATIBILITY.
  2853 
  2854 * Communication with Proof General is now 8bit clean, which means that
  2855 Unicode text in UTF-8 encoding may be used within theory texts (both
  2856 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2857 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2858 
  2859   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2860   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2861 
  2862 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2863 Classical Reasoner.  Typical big applications run around 2 times
  2864 faster.
  2865 
  2866 
  2867 *** Document preparation ***
  2868 
  2869 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2870 of raw sources.  Only those symbols that do not require additional
  2871 LaTeX packages (depending on comments in isabellesym.sty) are
  2872 displayed properly, everything else is left verbatim.  isatool display
  2873 and isatool print are used as front ends (these are subject to the
  2874 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2875 
  2876 * Command tags control specific markup of certain regions of text,
  2877 notably folding and hiding.  Predefined tags include "theory" (for
  2878 theory begin and end), "proof" for proof commands, and "ML" for
  2879 commands involving ML code; the additional tags "visible" and
  2880 "invisible" are unused by default.  Users may give explicit tag
  2881 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2882 interpretation of tags is determined by the LaTeX job during document
  2883 preparation: see option -V of isatool usedir, or options -n and -t of
  2884 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2885 \isadroptag.
  2886 
  2887 Several document versions may be produced at the same time via isatool
  2888 usedir (the generated index.html will link all of them).  Typical
  2889 specifications include ''-V document=theory,proof,ML'' to present
  2890 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2891 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2892 these parts without any formal replacement text.  The Isabelle site
  2893 default settings produce ''document'' and ''outline'' versions as
  2894 specified above.
  2895 
  2896 * Several new antiquotations:
  2897 
  2898   @{term_type term} prints a term with its type annotated;
  2899 
  2900   @{typeof term} prints the type of a term;
  2901 
  2902   @{const const} is the same as @{term const}, but checks that the
  2903   argument is a known logical constant;
  2904 
  2905   @{term_style style term} and @{thm_style style thm} print a term or
  2906   theorem applying a "style" to it
  2907 
  2908   @{ML text}
  2909 
  2910 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2911 definitions, equations, inequations etc., 'concl' printing only the
  2912 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2913 to print the specified premise.  TermStyle.add_style provides an ML
  2914 interface for introducing further styles.  See also the "LaTeX Sugar"
  2915 document practical applications.  The ML antiquotation prints
  2916 type-checked ML expressions verbatim.
  2917 
  2918 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2919 and 'text' support optional locale specification '(in loc)', which
  2920 specifies the default context for interpreting antiquotations.  For
  2921 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2922 
  2923 * Option 'locale=NAME' of antiquotations specifies an alternative
  2924 context interpreting the subsequent argument.  For example: @{thm
  2925 [locale=lattice] inf_assoc}.
  2926 
  2927 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2928 a proof context.
  2929 
  2930 * Proper output of antiquotations for theory commands involving a
  2931 proof context (such as 'locale' or 'theorem (in loc) ...').
  2932 
  2933 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2934 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2935 
  2936 * isatool usedir: new option -C (default true) controls whether option
  2937 -D should include a copy of the original document directory; -C false
  2938 prevents unwanted effects such as copying of administrative CVS data.
  2939 
  2940 
  2941 *** Pure ***
  2942 
  2943 * Considerably improved version of 'constdefs' command.  Now performs
  2944 automatic type-inference of declared constants; additional support for
  2945 local structure declarations (cf. locales and HOL records), see also
  2946 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2947 sequential dependencies of definitions within a single 'constdefs'
  2948 section; moreover, the declared name needs to be an identifier.  If
  2949 all fails, consider to fall back on 'consts' and 'defs' separately.
  2950 
  2951 * Improved indexed syntax and implicit structures.  First of all,
  2952 indexed syntax provides a notational device for subscripted
  2953 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2954 expressions.  Secondly, in a local context with structure
  2955 declarations, number indexes \<^sub>n or the empty index (default
  2956 number 1) refer to a certain fixed variable implicitly; option
  2957 show_structs controls printing of implicit structures.  Typical
  2958 applications of these concepts involve record types and locales.
  2959 
  2960 * New command 'no_syntax' removes grammar declarations (and
  2961 translations) resulting from the given syntax specification, which is
  2962 interpreted in the same manner as for the 'syntax' command.
  2963 
  2964 * 'Advanced' translation functions (parse_translation etc.) may depend
  2965 on the signature of the theory context being presently used for
  2966 parsing/printing, see also isar-ref manual.
  2967 
  2968 * Improved 'oracle' command provides a type-safe interface to turn an
  2969 ML expression of type theory -> T -> term into a primitive rule of
  2970 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2971 is already included here); see also FOL/ex/IffExample.thy;
  2972 INCOMPATIBILITY.
  2973 
  2974 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2975 before); "cI" is no longer bound, use "c.intro" instead.
  2976 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2977 axclasses vs. locales.
  2978 
  2979 * Improved internal renaming of symbolic identifiers -- attach primes
  2980 instead of base 26 numbers.
  2981 
  2982 * New flag show_question_marks controls printing of leading question
  2983 marks in schematic variable names.
  2984 
  2985 * In schematic variable names, *any* symbol following \<^isub> or
  2986 \<^isup> is now treated as part of the base name.  For example, the
  2987 following works without printing of awkward ".0" indexes:
  2988 
  2989   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2990     by simp
  2991 
  2992 * Inner syntax includes (*(*nested*) comments*).
  2993 
  2994 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2995 annotations as "(00...)".
  2996 
  2997 * Clear separation of logical types and nonterminals, where the latter
  2998 may only occur in 'syntax' specifications or type abbreviations.
  2999 Before that distinction was only partially implemented via type class
  3000 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3001 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3002 exotic syntax specifications may require further adaption
  3003 (e.g. Cube/Cube.thy).
  3004 
  3005 * Removed obsolete type class "logic", use the top sort {} instead.
  3006 Note that non-logical types should be declared as 'nonterminals'
  3007 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3008 specifications.
  3009 
  3010 * Attributes 'induct' and 'cases': type or set names may now be
  3011 locally fixed variables as well.
  3012 
  3013 * Simplifier: can now control the depth to which conditional rewriting
  3014 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3015 Limit.
  3016 
  3017 * Simplifier: simplification procedures may now take the current
  3018 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3019 interface), which is very useful for calling the Simplifier
  3020 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3021 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3022 low-level mk_simproc no longer applies Logic.varify internally, to
  3023 allow for use in a context of fixed variables.
  3024 
  3025 * thin_tac now works even if the assumption being deleted contains !!
  3026 or ==>.  More generally, erule now works even if the major premise of
  3027 the elimination rule contains !! or ==>.
  3028 
  3029 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3030 
  3031 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3032 from Pure, which contains all common declarations already.  Both
  3033 theories are defined via plain Isabelle/Isar .thy files.
  3034 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3035 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3036 use isatool fixcpure to adapt your theory and ML sources.
  3037 
  3038 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3039 selections of theorems in named facts via index ranges.
  3040 
  3041 * 'print_theorems': in theory mode, really print the difference
  3042 wrt. the last state (works for interactive theory development only),
  3043 in proof mode print all local facts (cf. 'print_facts');
  3044 
  3045 * 'hide': option '(open)' hides only base names.
  3046 
  3047 * More efficient treatment of intermediate checkpoints in interactive
  3048 theory development.
  3049 
  3050 * Code generator is now invoked via code_module (incremental code
  3051 generation) and code_library (modular code generation, ML structures
  3052 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3053 must be quoted when used as identifiers.
  3054 
  3055 * New 'value' command for reading, evaluating and printing terms using
  3056 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3057 quoted when used as identifier.
  3058 
  3059 
  3060 *** Locales ***
  3061 
  3062 * New commands for the interpretation of locale expressions in
  3063 theories (1), locales (2) and proof contexts (3).  These generate
  3064 proof obligations from the expression specification.  After the
  3065 obligations have been discharged, theorems of the expression are added
  3066 to the theory, target locale or proof context.  The synopsis of the
  3067 commands is a follows:
  3068 
  3069   (1) interpretation expr inst
  3070   (2) interpretation target < expr
  3071   (3) interpret expr inst
  3072 
  3073 Interpretation in theories and proof contexts require a parameter
  3074 instantiation of terms from the current context.  This is applied to
  3075 specifications and theorems of the interpreted expression.
  3076 Interpretation in locales only permits parameter renaming through the
  3077 locale expression.  Interpretation is smart in that interpretations
  3078 that are active already do not occur in proof obligations, neither are
  3079 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3080 inspect active interpretations of a particular locale.  For details,
  3081 see the Isar Reference manual.  Examples can be found in
  3082 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3083 
  3084 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3085 'interpret' instead.
  3086 
  3087 * New context element 'constrains' for adding type constraints to
  3088 parameters.
  3089 
  3090 * Context expressions: renaming of parameters with syntax
  3091 redeclaration.
  3092 
  3093 * Locale declaration: 'includes' disallowed.
  3094 
  3095 * Proper static binding of attribute syntax -- i.e. types / terms /
  3096 facts mentioned as arguments are always those of the locale definition
  3097 context, independently of the context of later invocations.  Moreover,
  3098 locale operations (renaming and type / term instantiation) are applied
  3099 to attribute arguments as expected.
  3100 
  3101 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3102 actual attributes; rare situations may require Attrib.attribute to
  3103 embed those attributes into Attrib.src that lack concrete syntax.
  3104 Attribute implementations need to cooperate properly with the static
  3105 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3106 Attrib.XXX_thm etc. already do the right thing without further
  3107 intervention.  Only unusual applications -- such as "where" or "of"
  3108 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3109 on the context and the facts involved -- may have to assign parsed
  3110 values to argument tokens explicitly.
  3111 
  3112 * Changed parameter management in theorem generation for long goal
  3113 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3114 theorem statement in rare situations.
  3115 
  3116 * Locale inspection command 'print_locale' omits notes elements.  Use
  3117 'print_locale!' to have them included in the output.
  3118 
  3119 
  3120 *** Provers ***
  3121 
  3122 * Provers/hypsubst.ML: improved version of the subst method, for
  3123 single-step rewriting: it now works in bound variable contexts. New is
  3124 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3125 rewrite a different subterm than the original subst method, which is
  3126 still available as 'simplesubst'.
  3127 
  3128 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3129 and quasi orders.
  3130 
  3131 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3132 reflexive-transitive closure of relations.
  3133 
  3134 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3135 limit (previously hard-coded with a value of 20) user-definable.
  3136 
  3137 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3138 is peformed already.  Object-logics merely need to finish their
  3139 initial simpset configuration as before.  INCOMPATIBILITY.
  3140 
  3141 
  3142 *** HOL ***
  3143 
  3144 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3145 
  3146   syntax (epsilon)
  3147     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3148 
  3149 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3150 and x-symbol; use option '-m epsilon' to get it actually printed.
  3151 Moreover, the mathematically important symbolic identifier \<epsilon>
  3152 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3153 
  3154 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3155 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3156 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3157 support corresponding Isar calculations.
  3158 
  3159 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3160 instead of ":".
  3161 
  3162 * theory SetInterval: changed the syntax for open intervals:
  3163 
  3164   Old       New
  3165   {..n(}    {..<n}
  3166   {)n..}    {n<..}
  3167   {m..n(}   {m..<n}
  3168   {)m..n}   {m<..n}
  3169   {)m..n(}  {m<..<n}
  3170 
  3171 The old syntax is still supported but will disappear in the next
  3172 release.  For conversion use the following Emacs search and replace
  3173 patterns (these are not perfect but work quite well):
  3174 
  3175   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3176   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3177 
  3178 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3179 equalities in commutative rings; method 'algebra' provides a generic
  3180 interface.
  3181 
  3182 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3183 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3184 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3185 be a tuple pattern.
  3186 
  3187 Some new syntax forms are available:
  3188 
  3189   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3190   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3191   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3192   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3193 
  3194 The latter form "\<Sum>x < k. e" used to be based on a separate
  3195 function "Summation", which has been discontinued.
  3196 
  3197 * theory Finite_Set: in structured induction proofs, the insert case
  3198 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3199 (insert F x)'.
  3200 
  3201 * The 'refute' command has been extended to support a much larger
  3202 fragment of HOL, including axiomatic type classes, constdefs and
  3203 typedefs, inductive datatypes and recursion.
  3204 
  3205 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3206 Requires zChaff with proof generation to be installed.  See
  3207 HOL/ex/SAT_Examples.thy for examples.
  3208 
  3209 * Datatype induction via method 'induct' now preserves the name of the
  3210 induction variable. For example, when proving P(xs::'a list) by
  3211 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3212 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3213 in unstructured proof scripts.
  3214 
  3215 * Reworked implementation of records.  Improved scalability for
  3216 records with many fields, avoiding performance problems for type
  3217 inference. Records are no longer composed of nested field types, but
  3218 of nested extension types. Therefore the record type only grows linear
  3219 in the number of extensions and not in the number of fields.  The
  3220 top-level (users) view on records is preserved.  Potential
  3221 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3222 old record representation. The type generated for a record is called
  3223 <record_name>_ext_type.
  3224 
  3225 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3226 proofs triggered by a record definition or a simproc (if
  3227 quick_and_dirty is enabled).  Definitions of large records can take
  3228 quite long.
  3229 
  3230 New simproc record_upd_simproc for simplification of multiple record
  3231 updates enabled by default.  Moreover, trivial updates are also
  3232 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3233 occasionally, since simplification is more powerful by default.
  3234 
  3235 * typedef: proper support for polymorphic sets, which contain extra
  3236 type-variables in the term.
  3237 
  3238 * Simplifier: automatically reasons about transitivity chains
  3239 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3240 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3241 old proofs break occasionally as simplification may now solve more
  3242 goals than previously.
  3243 
  3244 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3245 present.  Works for all partial orders (class "order"), in particular
  3246 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3247 just like y <= x.
  3248 
  3249 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3250 bound variable or a constant then the let is unfolded.  Otherwise
  3251 first a is simplified to b, and then f b is simplified to g. If
  3252 possible we abstract b from g arriving at "let x = b in h x",
  3253 otherwise we unfold the let and arrive at g.  The simproc can be
  3254 enabled/disabled by the reference use_let_simproc.  Potential
  3255 INCOMPATIBILITY since simplification is more powerful by default.
  3256 
  3257 * Classical reasoning: the meson method now accepts theorems as arguments.
  3258 
  3259 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3260 jobs to provide advice on the provability of subgoals.
  3261 
  3262 * Theory OrderedGroup and Ring_and_Field: various additions and
  3263 improvements to faciliate calculations involving equalities and
  3264 inequalities.
  3265 
  3266 The following theorems have been eliminated or modified
  3267 (INCOMPATIBILITY):
  3268 
  3269   abs_eq             now named abs_of_nonneg
  3270   abs_of_ge_0        now named abs_of_nonneg
  3271   abs_minus_eq       now named abs_of_nonpos
  3272   imp_abs_id         now named abs_of_nonneg
  3273   imp_abs_neg_id     now named abs_of_nonpos
  3274   mult_pos           now named mult_pos_pos
  3275   mult_pos_le        now named mult_nonneg_nonneg
  3276   mult_pos_neg_le    now named mult_nonneg_nonpos
  3277   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3278   mult_neg           now named mult_neg_neg
  3279   mult_neg_le        now named mult_nonpos_nonpos
  3280 
  3281 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3282      
  3283      zero_le_square
  3284      not_square_less_zero 
  3285 
  3286   The following lemmas have been deleted from Real/RealPow:
  3287   
  3288      realpow_zero_zero
  3289      realpow_two
  3290      realpow_less
  3291      zero_le_power
  3292      realpow_two_le
  3293      abs_realpow_two
  3294      realpow_two_abs     
  3295 
  3296 * Theory Parity: added rules for simplifying exponents.
  3297 
  3298 * Theory List:
  3299 
  3300 The following theorems have been eliminated or modified
  3301 (INCOMPATIBILITY):
  3302 
  3303   list_all_Nil       now named list_all.simps(1)
  3304   list_all_Cons      now named list_all.simps(2)
  3305   list_all_conv      now named list_all_iff
  3306   set_mem_eq         now named mem_iff
  3307 
  3308 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3309 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3310 
  3311 
  3312 *** HOL-Complex ***
  3313 
  3314 * Theory RealDef: better support for embedding natural numbers and
  3315 integers in the reals.
  3316 
  3317 The following theorems have been eliminated or modified
  3318 (INCOMPATIBILITY):
  3319 
  3320   exp_ge_add_one_self  now requires no hypotheses
  3321   real_of_int_add      reversed direction of equality (use [symmetric])
  3322   real_of_int_minus    reversed direction of equality (use [symmetric])
  3323   real_of_int_diff     reversed direction of equality (use [symmetric])
  3324   real_of_int_mult     reversed direction of equality (use [symmetric])
  3325 
  3326 * Theory RComplete: expanded support for floor and ceiling functions.
  3327 
  3328 * Theory Ln is new, with properties of the natural logarithm
  3329 
  3330 * Hyperreal: There is a new type constructor "star" for making
  3331 nonstandard types.  The old type names are now type synonyms:
  3332 
  3333   hypreal = real star
  3334   hypnat = nat star
  3335   hcomplex = complex star
  3336 
  3337 * Hyperreal: Many groups of similarly-defined constants have been
  3338 replaced by polymorphic versions (INCOMPATIBILITY):
  3339 
  3340   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3341 
  3342   starset      <-- starsetNat, starsetC
  3343   *s*          <-- *sNat*, *sc*
  3344   starset_n    <-- starsetNat_n, starsetC_n
  3345   *sn*         <-- *sNatn*, *scn*
  3346   InternalSets <-- InternalNatSets, InternalCSets
  3347 
  3348   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3349   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3350   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3351   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3352   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3353 
  3354 * Hyperreal: Many type-specific theorems have been removed in favor of
  3355 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3356 
  3357   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3358   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3359   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3360   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3361   right_minus <-- hypreal_add_minus
  3362   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3363   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3364   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3365   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3366   mult_1_right <-- hcomplex_mult_one_right
  3367   mult_zero_left <-- hcomplex_mult_zero_left
  3368   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3369   right_distrib <-- hypnat_add_mult_distrib2
  3370   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3371   right_inverse <-- hypreal_mult_inverse
  3372   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3373   order_refl <-- {hypreal,hypnat}_le_refl
  3374   order_trans <-- {hypreal,hypnat}_le_trans
  3375   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3376   order_less_le <-- {hypreal,hypnat}_less_le
  3377   linorder_linear <-- {hypreal,hypnat}_le_linear
  3378   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3379   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3380   add_nonneg_nonneg <-- hypreal_le_add_order
  3381 
  3382 * Hyperreal: Separate theorems having to do with type-specific
  3383 versions of constants have been merged into theorems that apply to the
  3384 new polymorphic constants (INCOMPATIBILITY):
  3385 
  3386   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3387   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3388   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3389   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3390   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3391   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3392   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3393   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3394   STAR_diff <-- {STAR,STARC}_diff
  3395   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3396     STARC_hcomplex_of_complex}_image_subset
  3397   starset_n_Un <-- starset{Nat,C}_n_Un
  3398   starset_n_Int <-- starset{Nat,C}_n_Int
  3399   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3400   starset_n_diff <-- starset{Nat,C}_n_diff
  3401   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3402   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3403   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3404   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3405   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3406   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3407   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3408   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3409   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3410   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3411   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3412   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3413   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3414   starfun_diff <-- starfun{C,RC,CR}_diff
  3415   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3416   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3417   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3418   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3419   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3420   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3421   starfun_Id <-- starfunC_Id
  3422   starfun_approx <-- starfun{Nat,CR}_approx
  3423   starfun_capprox <-- starfun{C,RC}_capprox
  3424   starfun_abs <-- starfunNat_rabs
  3425   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3426   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3427   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3428   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3429   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3430   starfun_add_approx <-- starfunCR_add_approx
  3431   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3432   starfun_divide <-- starfun{C,CR,RC}_divide
  3433   starfun_n <-- starfun{Nat,C}_n
  3434   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3435   starfun_n_add <-- starfun{Nat,C}_n_add
  3436   starfun_n_add_minus <-- starfunNat_n_add_minus
  3437   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3438   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3439   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3440 
  3441   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3442   star_n_minus <-- {hypreal,hcomplex}_minus
  3443   star_n_diff <-- {hypreal,hcomplex}_diff
  3444   star_n_mult <-- {hypreal,hcomplex}_mult
  3445   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3446   star_n_le <-- {hypreal,hypnat}_le
  3447   star_n_less <-- {hypreal,hypnat}_less
  3448   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3449   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3450   star_n_abs <-- hypreal_hrabs
  3451   star_n_divide <-- hcomplex_divide
  3452 
  3453   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3454   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3455   star_of_diff <-- hypreal_of_real_diff
  3456   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3457   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3458   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3459   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3460   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3461   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3462   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3463   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3464   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3465   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3466   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3467   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3468   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3469   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3470   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3471   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3472   star_of_power <-- hypreal_of_real_power
  3473   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3474 
  3475 * Hyperreal: new method "transfer" that implements the transfer
  3476 principle of nonstandard analysis. With a subgoal that mentions
  3477 nonstandard types like "'a star", the command "apply transfer"
  3478 replaces it with an equivalent one that mentions only standard types.
  3479 To be successful, all free variables must have standard types; non-
  3480 standard variables must have explicit universal quantifiers.
  3481 
  3482 * Hyperreal: A theory of Taylor series.
  3483 
  3484 
  3485 *** HOLCF ***
  3486 
  3487 * Discontinued special version of 'constdefs' (which used to support
  3488 continuous functions) in favor of the general Pure one with full
  3489 type-inference.
  3490 
  3491 * New simplification procedure for solving continuity conditions; it
  3492 is much faster on terms with many nested lambda abstractions (cubic
  3493 instead of exponential time).
  3494 
  3495 * New syntax for domain package: selector names are now optional.
  3496 Parentheses should be omitted unless argument is lazy, for example:
  3497 
  3498   domain 'a stream = cons "'a" (lazy "'a stream")
  3499 
  3500 * New command 'fixrec' for defining recursive functions with pattern
  3501 matching; defining multiple functions with mutual recursion is also
  3502 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3503 sinr, or any data constructor defined by the domain package. The given
  3504 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3505 syntax and examples.
  3506 
  3507 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3508 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3509 but the proof obligation additionally includes an admissibility
  3510 requirement. The packages generate instances of class cpo or pcpo,
  3511 with continuity and strictness theorems for Rep and Abs.
  3512 
  3513 * HOLCF: Many theorems have been renamed according to a more standard naming
  3514 scheme (INCOMPATIBILITY):
  3515 
  3516   foo_inject:  "foo$x = foo$y ==> x = y"
  3517   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3518   foo_less:    "(foo$x << foo$y) = (x << y)"
  3519   foo_strict:  "foo$UU = UU"
  3520   foo_defined: "... ==> foo$x ~= UU"
  3521   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3522 
  3523 
  3524 *** ZF ***
  3525 
  3526 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3527 including the First Isomorphism Theorem (on quotienting by the kernel
  3528 of a homomorphism).
  3529 
  3530 * ZF/Simplifier: install second copy of type solver that actually
  3531 makes use of TC rules declared to Isar proof contexts (or locales);
  3532 the old version is still required for ML proof scripts.
  3533 
  3534 
  3535 *** Cube ***
  3536 
  3537 * Converted to Isar theory format; use locales instead of axiomatic
  3538 theories.
  3539 
  3540 
  3541 *** ML ***
  3542 
  3543 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3544 for ||>, ||>>, |>>,
  3545 
  3546 * Pure/library.ML no longer defines its own option datatype, but uses
  3547 that of the SML basis, which has constructors NONE and SOME instead of
  3548 None and Some, as well as exception Option.Option instead of OPTION.
  3549 The functions the, if_none, is_some, is_none have been adapted
  3550 accordingly, while Option.map replaces apsome.
  3551 
  3552 * Pure/library.ML: the exception LIST has been given up in favour of
  3553 the standard exceptions Empty and Subscript, as well as
  3554 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3555 superceded by the standard hd and tl functions etc.
  3556 
  3557 A number of basic list functions are no longer exported to the ML
  3558 toplevel, as they are variants of predefined functions.  The following
  3559 suggests how one can translate existing code:
  3560 
  3561     rev_append xs ys = List.revAppend (xs, ys)
  3562     nth_elem (i, xs) = List.nth (xs, i)
  3563     last_elem xs = List.last xs
  3564     flat xss = List.concat xss
  3565     seq fs = List.app fs
  3566     partition P xs = List.partition P xs
  3567     mapfilter f xs = List.mapPartial f xs
  3568 
  3569 * Pure/library.ML: several combinators for linear functional
  3570 transformations, notably reverse application and composition:
  3571 
  3572   x |> f                f #> g
  3573   (x, y) |-> f          f #-> g
  3574 
  3575 * Pure/library.ML: introduced/changed precedence of infix operators:
  3576 
  3577   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3578   infix 2 ?;
  3579   infix 3 o oo ooo oooo;
  3580   infix 4 ~~ upto downto;
  3581 
  3582 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3583 infix operators.
  3584 
  3585 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3586 fold_map support linear functional transformations and nesting.  For
  3587 example:
  3588 
  3589   fold f [x1, ..., xN] y =
  3590     y |> f x1 |> ... |> f xN
  3591 
  3592   (fold o fold) f [xs1, ..., xsN] y =
  3593     y |> fold f xs1 |> ... |> fold f xsN
  3594 
  3595   fold f [x1, ..., xN] =
  3596     f x1 #> ... #> f xN
  3597 
  3598   (fold o fold) f [xs1, ..., xsN] =
  3599     fold f xs1 #> ... #> fold f xsN
  3600 
  3601 * Pure/library.ML: the following selectors on type 'a option are
  3602 available:
  3603 
  3604   the:               'a option -> 'a  (*partial*)
  3605   these:             'a option -> 'a  where 'a = 'b list
  3606   the_default: 'a -> 'a option -> 'a
  3607   the_list:          'a option -> 'a list
  3608 
  3609 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3610 basic operations for association lists, following natural argument
  3611 order; moreover the explicit equality predicate passed here avoids
  3612 potentially expensive polymorphic runtime equality checks.
  3613 The old functions may be expressed as follows:
  3614 
  3615   assoc = uncurry (AList.lookup (op =))
  3616   assocs = these oo AList.lookup (op =)
  3617   overwrite = uncurry (AList.update (op =)) o swap
  3618 
  3619 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3620 
  3621   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3622   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3623 
  3624 replacing make_keylist and keyfilter (occassionally used)
  3625 Naive rewrites:
  3626 
  3627   make_keylist = AList.make
  3628   keyfilter = AList.find (op =)
  3629 
  3630 * eq_fst and eq_snd now take explicit equality parameter, thus
  3631   avoiding eqtypes. Naive rewrites:
  3632 
  3633     eq_fst = eq_fst (op =)
  3634     eq_snd = eq_snd (op =)
  3635 
  3636 * Removed deprecated apl and apr (rarely used).
  3637   Naive rewrites:
  3638 
  3639     apl (n, op) =>>= curry op n
  3640     apr (op, m) =>>= fn n => op (n, m)
  3641 
  3642 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3643 provides a reasonably efficient light-weight implementation of sets as
  3644 lists.
  3645 
  3646 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3647 few new operations; existing lookup and update are now curried to
  3648 follow natural argument order (for use with fold etc.);
  3649 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3650 
  3651 * Pure/General: output via the Isabelle channels of
  3652 writeln/warning/error etc. is now passed through Output.output, with a
  3653 hook for arbitrary transformations depending on the print_mode
  3654 (cf. Output.add_mode -- the first active mode that provides a output
  3655 function wins).  Already formatted output may be embedded into further
  3656 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3657 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3658 accommodate easy composition of diagnostic messages etc.  Programmers
  3659 rarely need to care about Output.output or Output.raw at all, with
  3660 some notable exceptions: Output.output is required when bypassing the
  3661 standard channels (writeln etc.), or in token translations to produce
  3662 properly formatted results; Output.raw is required when capturing
  3663 already output material that will eventually be presented to the user
  3664 a second time.  For the default print mode, both Output.output and
  3665 Output.raw have no effect.
  3666 
  3667 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3668 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3669 cumulative results are displayed at the end of a batch session.
  3670 
  3671 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3672 replaced by File.platform_path and File.shell_path (with appropriate
  3673 hooks).  This provides a clean interface for unusual systems where the
  3674 internal and external process view of file names are different.
  3675 
  3676 * Pure: more efficient orders for basic syntactic entities: added
  3677 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3678 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3679 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3680 orders now -- potential INCOMPATIBILITY for code that depends on a
  3681 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3682 Library.sort_strings on result).
  3683 
  3684 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3685 fold_types traverse types/terms from left to right, observing natural
  3686 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3687 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3688 
  3689 * Pure: name spaces have been refined, with significant changes of the
  3690 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3691 to extern(_table).  The plain name entry path is superceded by a
  3692 general 'naming' context, which also includes the 'policy' to produce
  3693 a fully qualified name and external accesses of a fully qualified
  3694 name; NameSpace.extend is superceded by context dependent
  3695 Sign.declare_name.  Several theory and proof context operations modify
  3696 the naming context.  Especially note Theory.restore_naming and
  3697 ProofContext.restore_naming to get back to a sane state; note that
  3698 Theory.add_path is no longer sufficient to recover from
  3699 Theory.absolute_path in particular.
  3700 
  3701 * Pure: new flags short_names (default false) and unique_names
  3702 (default true) for controlling output of qualified names.  If
  3703 short_names is set, names are printed unqualified.  If unique_names is
  3704 reset, the name prefix is reduced to the minimum required to achieve
  3705 the original result when interning again, even if there is an overlap
  3706 with earlier declarations.
  3707 
  3708 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3709 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3710 (useful for printing error messages).  INCOMPATIBILITY.
  3711 
  3712 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3713 Theory.theory are now identified, referring to the universal
  3714 Context.theory (see Pure/context.ML).  Actual signature and theory
  3715 content is managed as theory data.  The old code and interfaces were
  3716 spread over many files and structures; the new arrangement introduces
  3717 considerable INCOMPATIBILITY to gain more clarity:
  3718 
  3719   Context -- theory management operations (name, identity, inclusion,
  3720     parents, ancestors, merge, etc.), plus generic theory data;
  3721 
  3722   Sign -- logical signature and syntax operations (declaring consts,
  3723     types, etc.), plus certify/read for common entities;
  3724 
  3725   Theory -- logical theory operations (stating axioms, definitions,
  3726     oracles), plus a copy of logical signature operations (consts,
  3727     types, etc.); also a few basic management operations (Theory.copy,
  3728     Theory.merge, etc.)
  3729 
  3730 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3731 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3732 for convenience -- they merely return the theory.
  3733 
  3734 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3735 
  3736 * Pure: the Isar proof context type is already defined early in Pure
  3737 as Context.proof (note that ProofContext.context and Proof.context are
  3738 aliases, where the latter is the preferred name).  This enables other
  3739 Isabelle components to refer to that type even before Isar is present.
  3740 
  3741 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3742 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3743 any of these kinds.  For example, Sign.intern typeK is now
  3744 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3745 Theory.hide_types.  Also note that former
  3746 Theory.hide_classes/types/consts are now
  3747 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3748 internalize their arguments!  INCOMPATIBILITY.
  3749 
  3750 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3751 datatype thmref (with constructors Name and NameSelection) instead of
  3752 plain string -- INCOMPATIBILITY;
  3753 
  3754 * Pure: cases produced by proof methods specify options, where NONE
  3755 means to remove case bindings -- INCOMPATIBILITY in
  3756 (RAW_)METHOD_CASES.
  3757 
  3758 * Pure: the following operations retrieve axioms or theorems from a
  3759 theory node or theory hierarchy, respectively:
  3760 
  3761   Theory.axioms_of: theory -> (string * term) list
  3762   Theory.all_axioms_of: theory -> (string * term) list
  3763   PureThy.thms_of: theory -> (string * thm) list
  3764   PureThy.all_thms_of: theory -> (string * thm) list
  3765 
  3766 * Pure: print_tac now outputs the goal through the trace channel.
  3767 
  3768 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3769 Reference Toplevel.debug (default false) controls detailed printing
  3770 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3771 controls execution profiling -- set to 1 for time and 2 for space
  3772 (both increase the runtime).
  3773 
  3774 * Isar session: The initial use of ROOT.ML is now always timed,
  3775 i.e. the log will show the actual process times, in contrast to the
  3776 elapsed wall-clock time that the outer shell wrapper produces.
  3777 
  3778 * Simplifier: improved handling of bound variables (nameless
  3779 representation, avoid allocating new strings).  Simprocs that invoke
  3780 the Simplifier recursively should use Simplifier.inherit_bounds to
  3781 avoid local name clashes.  Failure to do so produces warnings
  3782 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3783 for further details.
  3784 
  3785 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3786 bindings for all theorems stored within a given theory; this may help
  3787 in porting non-Isar theories to Isar ones, while keeping ML proof
  3788 scripts for the time being.
  3789 
  3790 * ML operator HTML.with_charset specifies the charset begin used for
  3791 generated HTML files.  For example:
  3792 
  3793   HTML.with_charset "utf-8" use_thy "Hebrew";
  3794   HTML.with_charset "utf-8" use_thy "Chinese";
  3795 
  3796 
  3797 *** System ***
  3798 
  3799 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3800 isabelle, isatool etc.).
  3801 
  3802 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3803 isatool doc, isatool mkdir, display_drafts etc.).
  3804 
  3805 * isatool usedir: option -f allows specification of the ML file to be
  3806 used by Isabelle; default is ROOT.ML.
  3807 
  3808 * New isatool version outputs the version identifier of the Isabelle
  3809 distribution being used.
  3810 
  3811 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3812 (containing Boolean satisfiability problems) into Isabelle/HOL
  3813 theories.
  3814 
  3815 
  3816 
  3817 New in Isabelle2004 (April 2004)
  3818 --------------------------------
  3819 
  3820 *** General ***
  3821 
  3822 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3823   Replaces linorder.ML.
  3824 
  3825 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3826   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3827   (\<a>...\<z>), are now considered normal letters, and can therefore
  3828   be used anywhere where an ASCII letter (a...zA...Z) has until
  3829   now. COMPATIBILITY: This obviously changes the parsing of some
  3830   terms, especially where a symbol has been used as a binder, say
  3831   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3832   as an identifier.  Fix it by inserting a space around former
  3833   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3834   existing theory and ML files.
  3835 
  3836 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3837 
  3838 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3839   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3840   a normal (but invisible) letter. For multiple letter subscripts repeat
  3841   \<^isub> like this: x\<^isub>1\<^isub>2.
  3842 
  3843 * Pure: There are now sub-/superscripts that can span more than one
  3844   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3845   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3846   superscript. The new control characters are not identifier parts.
  3847 
  3848 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3849   content of "..." to the latex file instead of \isacntrl... . The "..."
  3850   may consist of any printable characters excluding the end bracket >.
  3851 
  3852 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3853   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3854   declare constants "final", which prevents their being given a definition
  3855   later.  It is useful for constants whose behaviour is fixed axiomatically
  3856   rather than definitionally, such as the meta-logic connectives.
  3857 
  3858 * Pure: 'instance' now handles general arities with general sorts
  3859   (i.e. intersections of classes),
  3860 
  3861 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3862   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3863   It can be changed to alter the colors/layout of generated pages.
  3864 
  3865 
  3866 *** Isar ***
  3867 
  3868 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3869   cut_tac, subgoal_tac and thin_tac:
  3870   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3871     locales are no longer forced to write Isar proof scripts.
  3872     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3873     emulations.
  3874   - INCOMPATIBILITY: names of variables to be instantiated may no
  3875     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3876     This is consistent with the instantiation attribute "where".
  3877 
  3878 * Attributes "where" and "of":
  3879   - Now take type variables of instantiated theorem into account when reading
  3880     the instantiation string.  This fixes a bug that caused instantiated
  3881     theorems to have too special types in some circumstances.
  3882   - "where" permits explicit instantiations of type variables.
  3883 
  3884 * Calculation commands "moreover" and "also" no longer interfere with
  3885   current facts ("this"), admitting arbitrary combinations with "then"
  3886   and derived forms.
  3887 
  3888 * Locales:
  3889   - Goal statements involving the context element "includes" no longer
  3890     generate theorems with internal delta predicates (those ending on
  3891     "_axioms") in the premise.
  3892     Resolve particular premise with <locale>.intro to obtain old form.
  3893   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3894     specification and "includes" elements in goal statement.
  3895   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3896     [intro?] and [elim?] (respectively) by default.
  3897   - Experimental command for instantiation of locales in proof contexts:
  3898         instantiate <label>[<attrs>]: <loc>
  3899     Instantiates locale <loc> and adds all its theorems to the current context
  3900     taking into account their attributes.  Label and attrs are optional
  3901     modifiers, like in theorem declarations.  If present, names of
  3902     instantiated theorems are qualified with <label>, and the attributes
  3903     <attrs> are applied after any attributes these theorems might have already.
  3904       If the locale has assumptions, a chained fact of the form
  3905     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3906     are derived.  The command does not support old-style locales declared
  3907     with "locale (open)".
  3908       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3909 
  3910 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3911   (Isar) contexts.
  3912 
  3913 
  3914 *** HOL ***
  3915 
  3916 * Proof import: new image HOL4 contains the imported library from
  3917   the HOL4 system with about 2500 theorems. It is imported by
  3918   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3919   can be used like any other Isabelle image.  See
  3920   HOL/Import/HOL/README for more information.
  3921 
  3922 * Simplifier:
  3923   - Much improved handling of linear and partial orders.
  3924     Reasoners for linear and partial orders are set up for type classes
  3925     "linorder" and "order" respectively, and are added to the default simpset
  3926     as solvers.  This means that the simplifier can build transitivity chains
  3927     to solve goals from the assumptions.
  3928   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3929     of blast or auto after simplification become unnecessary because the goal
  3930     is solved by simplification already.
  3931 
  3932 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3933     all proved in axiomatic type classes for semirings, rings and fields.
  3934 
  3935 * Numerics:
  3936   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3937     now formalized using the Ring_and_Field theory mentioned above.
  3938   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3939     than before, because now they are set up once in a generic manner.
  3940   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3941     Look for the general versions in Ring_and_Field (and Power if they concern
  3942     exponentiation).
  3943 
  3944 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3945 
  3946 * Records:
  3947   - Record types are now by default printed with their type abbreviation
  3948     instead of the list of all field types. This can be configured via
  3949     the reference "print_record_type_abbr".
  3950   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3951     (not enabled by default).
  3952   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3953     EX x. x = sel r to True (not enabled by default).
  3954   - Tactic "record_split_simp_tac" to split and simplify records added.
  3955 
  3956 * 'specification' command added, allowing for definition by
  3957   specification.  There is also an 'ax_specification' command that
  3958   introduces the new constants axiomatically.
  3959 
  3960 * arith(_tac) is now able to generate counterexamples for reals as well.
  3961 
  3962 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3963 
  3964 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3965   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3966 
  3967 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3968   matrix theory to linear programming.
  3969 
  3970 * Unions and Intersections:
  3971   The latex output syntax of UN and INT has been changed
  3972   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3973   i.e. the index formulae has become a subscript.
  3974   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3975 
  3976 * Unions and Intersections over Intervals:
  3977   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3978   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3979   like in normal math, and corresponding versions for < and for intersection.
  3980 
  3981 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3982   lexicographic dictonary ordering has been added as "lexord".
  3983 
  3984 * ML: the legacy theory structures Int and List have been removed. They had
  3985   conflicted with ML Basis Library structures having the same names.
  3986 
  3987 * 'refute' command added to search for (finite) countermodels.  Only works
  3988   for a fragment of HOL.  The installation of an external SAT solver is
  3989   highly recommended.  See "HOL/Refute.thy" for details.
  3990 
  3991 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3992   formulae under an assignment of free variables to random values.
  3993   In contrast to 'refute', it can deal with inductive datatypes,
  3994   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3995   for examples.
  3996 
  3997 
  3998 *** HOLCF ***
  3999 
  4000 * Streams now come with concatenation and are part of the HOLCF image
  4001 
  4002 
  4003 
  4004 New in Isabelle2003 (May 2003)
  4005 ------------------------------
  4006 
  4007 *** General ***
  4008 
  4009 * Provers/simplifier:
  4010 
  4011   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4012     Assumptions are now subject to complete mutual simplification,
  4013     not just from left to right. The simplifier now preserves
  4014     the order of assumptions.
  4015 
  4016     Potential INCOMPATIBILITY:
  4017 
  4018     -- simp sometimes diverges where the old version did
  4019        not, e.g. invoking simp on the goal
  4020 
  4021         [| P (f x); y = x; f x = f y |] ==> Q
  4022 
  4023        now gives rise to the infinite reduction sequence
  4024 
  4025         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4026 
  4027        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4028        kind of problem.
  4029 
  4030     -- Tactics combining classical reasoner and simplification (such as auto)
  4031        are also affected by this change, because many of them rely on
  4032        simp. They may sometimes diverge as well or yield a different numbers
  4033        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4034        in case of problems. Sometimes subsequent calls to the classical
  4035        reasoner will fail because a preceeding call to the simplifier too
  4036        eagerly simplified the goal, e.g. deleted redundant premises.
  4037 
  4038   - The simplifier trace now shows the names of the applied rewrite rules
  4039 
  4040   - You can limit the number of recursive invocations of the simplifier
  4041     during conditional rewriting (where the simplifie tries to solve the
  4042     conditions before applying the rewrite rule):
  4043     ML "simp_depth_limit := n"
  4044     where n is an integer. Thus you can force termination where previously
  4045     the simplifier would diverge.
  4046 
  4047   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4048 
  4049   - No longer aborts on failed congruence proof.  Instead, the
  4050     congruence is ignored.
  4051 
  4052 * Pure: New generic framework for extracting programs from constructive
  4053   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4054   as HOL/Extraction for some case studies.
  4055 
  4056 * Pure: The main goal of the proof state is no longer shown by default, only
  4057 the subgoals. This behaviour is controlled by a new flag.
  4058    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4059 (ML: Proof.show_main_goal).
  4060 
  4061 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4062 rules whose conclusion matches subgoal 1:
  4063       PG menu: Isabelle/Isar -> Show me -> matching rules
  4064 The rules are ordered by how closely they match the subgoal.
  4065 In particular, rules that solve a subgoal outright are displayed first
  4066 (or rather last, the way they are printed).
  4067 (ML: ProofGeneral.print_intros())
  4068 
  4069 * Pure: New flag trace_unify_fail causes unification to print
  4070 diagnostic information (PG: in trace buffer) when it fails. This is
  4071 useful for figuring out why single step proofs like rule, erule or
  4072 assumption failed.
  4073 
  4074 * Pure: Locale specifications now produce predicate definitions
  4075 according to the body of text (covering assumptions modulo local
  4076 definitions); predicate "loc_axioms" covers newly introduced text,
  4077 while "loc" is cumulative wrt. all included locale expressions; the
  4078 latter view is presented only on export into the global theory
  4079 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4080 on the old view without predicates;
  4081 
  4082 * Pure: predefined locales "var" and "struct" are useful for sharing
  4083 parameters (as in CASL, for example); just specify something like
  4084 ``var x + var y + struct M'' as import;
  4085 
  4086 * Pure: improved thms_containing: proper indexing of facts instead of
  4087 raw theorems; check validity of results wrt. current name space;
  4088 include local facts of proof configuration (also covers active
  4089 locales), cover fixed variables in index; may use "_" in term
  4090 specification; an optional limit for the number of printed facts may
  4091 be given (the default is 40);
  4092 
  4093 * Pure: disallow duplicate fact bindings within new-style theory files
  4094 (batch-mode only);
  4095 
  4096 * Provers: improved induct method: assumptions introduced by case
  4097 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4098 the goal statement); "foo" still refers to all facts collectively;
  4099 
  4100 * Provers: the function blast.overloaded has been removed: all constants
  4101 are regarded as potentially overloaded, which improves robustness in exchange
  4102 for slight decrease in efficiency;
  4103 
  4104 * Provers/linorder: New generic prover for transitivity reasoning over
  4105 linear orders.  Note: this prover is not efficient!
  4106 
  4107 * Isar: preview of problems to finish 'show' now produce an error
  4108 rather than just a warning (in interactive mode);
  4109 
  4110 
  4111 *** HOL ***
  4112 
  4113 * arith(_tac)
  4114 
  4115  - Produces a counter example if it cannot prove a goal.
  4116    Note that the counter example may be spurious if the goal is not a formula
  4117    of quantifier-free linear arithmetic.
  4118    In ProofGeneral the counter example appears in the trace buffer.
  4119 
  4120  - Knows about div k and mod k where k is a numeral of type nat or int.
  4121 
  4122  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4123    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4124    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4125 
  4126 * simp's arithmetic capabilities have been enhanced a bit: it now
  4127 takes ~= in premises into account (by performing a case split);
  4128 
  4129 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4130 are distributed over a sum of terms;
  4131 
  4132 * New tactic "trans_tac" and method "trans" instantiate
  4133 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4134 "<=", "<" and "=").
  4135 
  4136 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4137 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4138 
  4139 * 'typedef' command has new option "open" to suppress the set
  4140 definition;
  4141 
  4142 * functions Min and Max on finite sets have been introduced (theory
  4143 Finite_Set);
  4144 
  4145 * attribute [symmetric] now works for relations as well; it turns
  4146 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4147 
  4148 * induct over a !!-quantified statement (say !!x1..xn):
  4149   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4150 
  4151 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4152 %x. None. Warning: empty_def now refers to the previously hidden definition
  4153 of the empty set.
  4154 
  4155 * Algebra: formalization of classical algebra.  Intended as base for
  4156 any algebraic development in Isabelle.  Currently covers group theory
  4157 (up to Sylow's theorem) and ring theory (Universal Property of
  4158 Univariate Polynomials).  Contributions welcome;
  4159 
  4160 * GroupTheory: deleted, since its material has been moved to Algebra;
  4161 
  4162 * Complex: new directory of the complex numbers with numeric constants,
  4163 nonstandard complex numbers, and some complex analysis, standard and
  4164 nonstandard (Jacques Fleuriot);
  4165 
  4166 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4167 
  4168 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4169 Fleuriot);
  4170 
  4171 * Real/HahnBanach: updated and adapted to locales;
  4172 
  4173 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4174 Gray and Kramer);
  4175 
  4176 * UNITY: added the Meier-Sanders theory of progress sets;
  4177 
  4178 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4179 as abstract algorithms, instantiated to the JVM;
  4180 
  4181 * Bali: Java source language formalization. Type system, operational
  4182 semantics, axiomatic semantics. Supported language features:
  4183 classes, interfaces, objects,virtual methods, static methods,
  4184 static/instance fields, arrays, access modifiers, definite
  4185 assignment, exceptions.
  4186 
  4187 
  4188 *** ZF ***
  4189 
  4190 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4191 universe, etc.);
  4192 
  4193 * Main ZF: virtually all theories converted to new-style format;
  4194 
  4195 
  4196 *** ML ***
  4197 
  4198 * Pure: Tactic.prove provides sane interface for internal proofs;
  4199 omits the infamous "standard" operation, so this is more appropriate
  4200 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4201 
  4202 * Pure: improved error reporting of simprocs;
  4203 
  4204 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4205 up simprocs;
  4206 
  4207 
  4208 *** Document preparation ***
  4209 
  4210 * uses \par instead of \\ for line breaks in theory text. This may
  4211 shift some page breaks in large documents. To get the old behaviour
  4212 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4213 
  4214 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4215 other packages
  4216 
  4217 * \<euro> now needs package babel/greek instead of marvosym (which
  4218 broke \Rightarrow)
  4219 
  4220 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4221 textcomp package)
  4222 
  4223 
  4224 
  4225 New in Isabelle2002 (March 2002)
  4226 --------------------------------
  4227 
  4228 *** Document preparation ***
  4229 
  4230 * greatly simplified document preparation setup, including more
  4231 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4232 instructive isatool mkdir; users should basically be able to get
  4233 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4234 users may run a separate document processing stage manually like this:
  4235 "isatool usedir -D output HOL Test && isatool document Test/output";
  4236 
  4237 * theory dependency graph may now be incorporated into documents;
  4238 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4239 with \includegraphics of LaTeX;
  4240 
  4241 * proper spacing of consecutive markup elements, especially text
  4242 blocks after section headings;
  4243 
  4244 * support bold style (for single symbols only), input syntax is like
  4245 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4246 
  4247 * \<bullet> is now output as bold \cdot by default, which looks much
  4248 better in printed text;
  4249 
  4250 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4251 note that these symbols are currently unavailable in Proof General /
  4252 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4253 
  4254 * isatool latex no longer depends on changed TEXINPUTS, instead
  4255 isatool document copies the Isabelle style files to the target
  4256 location;
  4257 
  4258 
  4259 *** Isar ***
  4260 
  4261 * Pure/Provers: improved proof by cases and induction;
  4262   - 'case' command admits impromptu naming of parameters (such as
  4263     "case (Suc n)");
  4264   - 'induct' method divinates rule instantiation from the inductive
  4265     claim; no longer requires excessive ?P bindings for proper
  4266     instantiation of cases;
  4267   - 'induct' method properly enumerates all possibilities of set/type
  4268     rules; as a consequence facts may be also passed through *type*
  4269     rules without further ado;
  4270   - 'induct' method now derives symbolic cases from the *rulified*
  4271     rule (before it used to rulify cases stemming from the internal
  4272     atomized version); this means that the context of a non-atomic
  4273     statement becomes is included in the hypothesis, avoiding the
  4274     slightly cumbersome show "PROP ?case" form;
  4275   - 'induct' may now use elim-style induction rules without chaining
  4276     facts, using ``missing'' premises from the goal state; this allows
  4277     rules stemming from inductive sets to be applied in unstructured
  4278     scripts, while still benefitting from proper handling of non-atomic
  4279     statements; NB: major inductive premises need to be put first, all
  4280     the rest of the goal is passed through the induction;
  4281   - 'induct' proper support for mutual induction involving non-atomic
  4282     rule statements (uses the new concept of simultaneous goals, see
  4283     below);
  4284   - append all possible rule selections, but only use the first
  4285     success (no backtracking);
  4286   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4287   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4288   - added 'print_induct_rules' (covered by help item in recent Proof
  4289     General versions);
  4290   - moved induct/cases attributes to Pure, methods to Provers;
  4291   - generic method setup instantiated for FOL and HOL;
  4292 
  4293 * Pure: support multiple simultaneous goal statements, for example
  4294 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4295 meta-level mechanism, this acts as if several individual goals had
  4296 been stated separately; in particular common proof methods need to be
  4297 repeated in order to cover all claims; note that a single elimination
  4298 step is *not* sufficient to establish the two conjunctions, so this
  4299 fails:
  4300 
  4301   assume "A & B" then have A and B ..   (*".." fails*)
  4302 
  4303 better use "obtain" in situations as above; alternative refer to
  4304 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4305 
  4306 * Pure: proper integration with ``locales''; unlike the original
  4307 version by Florian Kammller, Isar locales package high-level proof
  4308 contexts rather than raw logical ones (e.g. we admit to include
  4309 attributes everywhere); operations on locales include merge and
  4310 rename; support for implicit arguments (``structures''); simultaneous
  4311 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4312 some examples;
  4313 
  4314 * Pure: the following commands have been ``localized'', supporting a
  4315 target locale specification "(in name)": 'lemma', 'theorem',
  4316 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4317 stored both within the locale and at the theory level (exported and
  4318 qualified by the locale name);
  4319 
  4320 * Pure: theory goals may now be specified in ``long'' form, with
  4321 ad-hoc contexts consisting of arbitrary locale elements. for example
  4322 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4323 definitions may be given, too); the result is a meta-level rule with
  4324 the context elements being discharged in the obvious way;
  4325 
  4326 * Pure: new proof command 'using' allows to augment currently used
  4327 facts after a goal statement ('using' is syntactically analogous to
  4328 'apply', but acts on the goal's facts only); this allows chained facts
  4329 to be separated into parts given before and after a claim, as in
  4330 ``from a and b have C using d and e <proof>'';
  4331 
  4332 * Pure: renamed "antecedent" case to "rule_context";
  4333 
  4334 * Pure: new 'judgment' command records explicit information about the
  4335 object-logic embedding (used by several tools internally); no longer
  4336 use hard-wired "Trueprop";
  4337 
  4338 * Pure: added 'corollary' command;
  4339 
  4340 * Pure: fixed 'token_translation' command;
  4341 
  4342 * Pure: removed obsolete 'exported' attribute;
  4343 
  4344 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4345 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4346 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4347 
  4348 * Pure: method 'atomize' presents local goal premises as object-level
  4349 statements (atomic meta-level propositions); setup controlled via
  4350 rewrite rules declarations of 'atomize' attribute; example
  4351 application: 'induct' method with proper rule statements in improper
  4352 proof *scripts*;
  4353 
  4354 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4355 now consider the syntactic context of assumptions, giving a better
  4356 chance to get type-inference of the arguments right (this is
  4357 especially important for locales);
  4358 
  4359 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4360 mode;
  4361 
  4362 * Pure/obtain: the formal conclusion "thesis", being marked as
  4363 ``internal'', may no longer be reference directly in the text;
  4364 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4365 situations;
  4366 
  4367 * Pure: generic 'sym' attribute which declares a rule both as pure
  4368 'elim?' and for the 'symmetric' operation;
  4369 
  4370 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4371 text; the fixed correlation with particular command syntax has been
  4372 discontinued;
  4373 
  4374 * Pure: new method 'rules' is particularly well-suited for proof
  4375 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4376 but often produces more compact proof terms with less detours;
  4377 
  4378 * Pure/Provers/classical: simplified integration with pure rule
  4379 attributes and methods; the classical "intro?/elim?/dest?"
  4380 declarations coincide with the pure ones; the "rule" method no longer
  4381 includes classically swapped intros; "intro" and "elim" methods no
  4382 longer pick rules from the context; also got rid of ML declarations
  4383 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4384 INCOMPATIBILITY;
  4385 
  4386 * Provers/classical: attribute 'swapped' produces classical inversions
  4387 of introduction rules;
  4388 
  4389 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4390 rules instead of full simplifier context; 'iff' attribute handles
  4391 conditional rules;
  4392 
  4393 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4394 
  4395 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4396 "(permissive)" option to recover old behavior;
  4397 
  4398 * HOL: 'inductive' no longer features separate (collective) attributes
  4399 for 'intros' (was found too confusing);
  4400 
  4401 * HOL: properly declared induction rules less_induct and
  4402 wf_induct_rule;
  4403 
  4404 
  4405 *** HOL ***
  4406 
  4407 * HOL: moved over to sane numeral syntax; the new policy is as
  4408 follows:
  4409 
  4410   - 0 and 1 are polymorphic constants, which are defined on any
  4411   numeric type (nat, int, real etc.);
  4412 
  4413   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4414   binary representation internally;
  4415 
  4416   - type nat has special constructor Suc, and generally prefers Suc 0
  4417   over 1::nat and Suc (Suc 0) over 2::nat;
  4418 
  4419 This change may cause significant problems of INCOMPATIBILITY; here
  4420 are some hints on converting existing sources:
  4421 
  4422   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4423   entities, so expressions involving "-" (unary or binary minus) need
  4424   to be spaced properly;
  4425 
  4426   - existing occurrences of "1" may need to be constraint "1::nat" or
  4427   even replaced by Suc 0; similar for old "2";
  4428 
  4429   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4430 
  4431   - remove all special provisions on numerals in proofs;
  4432 
  4433 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4434 representation (depends on bin_arith_simps in the default context);
  4435 
  4436 * HOL: symbolic syntax for x^2 (numeral 2);
  4437 
  4438 * HOL: the class of all HOL types is now called "type" rather than
  4439 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4440 in axclass/classes, instance/arities, and (usually rare) occurrences
  4441 in typings (of consts etc.); internally the class is called
  4442 "HOL.type", ML programs should refer to HOLogic.typeS;
  4443 
  4444 * HOL/record package improvements:
  4445   - new derived operations "fields" to build a partial record section,
  4446     "extend" to promote a fixed record to a record scheme, and
  4447     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4448     declared as simp by default;
  4449   - shared operations ("more", "fields", etc.) now need to be always
  4450     qualified) --- potential INCOMPATIBILITY;
  4451   - removed "make_scheme" operations (use "make" with "extend") --
  4452     INCOMPATIBILITY;
  4453   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4454   - provides cases/induct rules for use with corresponding Isar
  4455     methods (for concrete records, record schemes, concrete more
  4456     parts, and schematic more parts -- in that order);
  4457   - internal definitions directly based on a light-weight abstract
  4458     theory of product types over typedef rather than datatype;
  4459 
  4460 * HOL: generic code generator for generating executable ML code from
  4461 specifications; specific support for HOL constructs such as inductive
  4462 datatypes and sets, as well as recursive functions; can be invoked
  4463 via 'generate_code' theory section;
  4464 
  4465 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4466 
  4467 * HOL: consolidated and renamed several theories.  In particular:
  4468         Ord.thy has been absorbed into HOL.thy
  4469         String.thy has been absorbed into List.thy
  4470 
  4471 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4472 (beware of argument permutation!);
  4473 
  4474 * HOL: linorder_less_split superseded by linorder_cases;
  4475 
  4476 * HOL/List: "nodups" renamed to "distinct";
  4477 
  4478 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4479 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4480   - Ex_def has changed, now need to use some_eq_ex
  4481 
  4482 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4483 in this (rare) case use:
  4484 
  4485   delSWrapper "split_all_tac"
  4486   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4487 
  4488 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4489 MAY FAIL;
  4490 
  4491 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4492 Isabelle's type classes, ^ on functions and relations has too general
  4493 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4494 necessary to attach explicit type constraints;
  4495 
  4496 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4497 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4498 renamed accordingly (eg "compI" -> "rel_compI").
  4499 
  4500 * HOL: syntax translations now work properly with numerals and records
  4501 expressions;
  4502 
  4503 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4504 of "lam" -- INCOMPATIBILITY;
  4505 
  4506 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4507 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4508 renamed "Product_Type.unit";
  4509 
  4510 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4511 
  4512 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4513 the "cases" method);
  4514 
  4515 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4516 Florian Kammller);
  4517 
  4518 * HOL/IMP: updated and converted to new-style theory format; several
  4519 parts turned into readable document, with proper Isar proof texts and
  4520 some explanations (by Gerwin Klein);
  4521 
  4522 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4523 
  4524 * HOL-Hyperreal is now a logic image;
  4525 
  4526 
  4527 *** HOLCF ***
  4528 
  4529 * Isar: consts/constdefs supports mixfix syntax for continuous
  4530 operations;
  4531 
  4532 * Isar: domain package adapted to new-style theory format, e.g. see
  4533 HOLCF/ex/Dnat.thy;
  4534 
  4535 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4536 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4537 lift.induct_tac, always use UU instead of Undef;
  4538 
  4539 * HOLCF/IMP: updated and converted to new-style theory;
  4540 
  4541 
  4542 *** ZF ***
  4543 
  4544 * Isar: proper integration of logic-specific tools and packages,
  4545 including theory commands '(co)inductive', '(co)datatype',
  4546 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4547 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4548 
  4549 * theory Main no longer includes AC; for the Axiom of Choice, base
  4550 your theory on Main_ZFC;
  4551 
  4552 * the integer library now covers quotients and remainders, with many
  4553 laws relating division to addition, multiplication, etc.;
  4554 
  4555 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4556 typeless version of the formalism;
  4557 
  4558 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4559 format;
  4560 
  4561 * ZF/Induct: new directory for examples of inductive definitions,
  4562 including theory Multiset for multiset orderings; converted to
  4563 new-style theory format;
  4564 
  4565 * ZF: many new theorems about lists, ordinals, etc.;
  4566 
  4567 
  4568 *** General ***
  4569 
  4570 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4571 variable proof controls level of detail: 0 = no proofs (only oracle
  4572 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4573 also ref manual for further ML interfaces;
  4574 
  4575 * Pure/axclass: removed obsolete ML interface
  4576 goal_subclass/goal_arity;
  4577 
  4578 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4579 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4580 separate tokens, so expressions involving minus need to be spaced
  4581 properly;
  4582 
  4583 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4584 rather than "infixl" or "infixr";
  4585 
  4586 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4587 sort constraint specifications in type inference; e.g. "x::_::foo"
  4588 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4589 type variable);
  4590 
  4591 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4592 control output of nested => (types); the default behavior is
  4593 "type_brackets";
  4594 
  4595 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4596 tokens into AST constants;
  4597 
  4598 * Pure/syntax: prefer later declarations of translations and print
  4599 translation functions; potential INCOMPATIBILITY: need to reverse
  4600 multiple declarations for same syntax element constant;
  4601 
  4602 * Pure/show_hyps reset by default (in accordance to existing Isar
  4603 practice);
  4604 
  4605 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4606 addSafter;
  4607 
  4608 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4609 as well;
  4610 
  4611 * system: tested support for MacOS X; should be able to get Isabelle +
  4612 Proof General to work in a plain Terminal after installing Poly/ML
  4613 (e.g. from the Isabelle distribution area) and GNU bash alone
  4614 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4615 support requires further installations, e.g. from
  4616 http://fink.sourceforge.net/);
  4617 
  4618 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4619 
  4620 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4621 of 40 MB), cf. ML_OPTIONS;
  4622 
  4623 * system: Proof General keywords specification is now part of the
  4624 Isabelle distribution (see etc/isar-keywords.el);
  4625 
  4626 * system: support for persistent Proof General sessions (refrain from
  4627 outdating all loaded theories on startup); user may create writable
  4628 logic images like this: ``isabelle -q HOL Test'';
  4629 
  4630 * system: smart selection of Isabelle process versus Isabelle
  4631 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4632 run both "isabelle" and "Isabelle" even if file names are badly
  4633 damaged (executable inspects the case of the first letter of its own
  4634 name); added separate "isabelle-process" and "isabelle-interface";
  4635 
  4636 * system: refrain from any attempt at filtering input streams; no
  4637 longer support ``8bit'' encoding of old isabelle font, instead proper
  4638 iso-latin characters may now be used; the related isatools
  4639 "symbolinput" and "nonascii" have disappeared as well;
  4640 
  4641 * system: removed old "xterm" interface (the print modes "xterm" and
  4642 "xterm_color" are still available for direct use in a suitable
  4643 terminal);
  4644 
  4645 
  4646 
  4647 New in Isabelle99-2 (February 2001)
  4648 -----------------------------------
  4649 
  4650 *** Overview of INCOMPATIBILITIES ***
  4651 
  4652 * HOL: please note that theories in the Library and elsewhere often use the
  4653 new-style (Isar) format; to refer to their theorems in an ML script you must
  4654 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4655 
  4656 * HOL: inductive package no longer splits induction rule aggressively,
  4657 but only as far as specified by the introductions given; the old
  4658 format may be recovered via ML function complete_split_rule or attribute
  4659 'split_rule (complete)';
  4660 
  4661 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4662 gfp_Tarski to gfp_unfold;
  4663 
  4664 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4665 
  4666 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4667 relation); infix "^^" has been renamed "``"; infix "``" has been
  4668 renamed "`"; "univalent" has been renamed "single_valued";
  4669 
  4670 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4671 operation;
  4672 
  4673 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4674 
  4675 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4676 
  4677 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4678 consequence, it is no longer monotonic wrt. the local goal context
  4679 (which is now passed through the inductive cases);
  4680 
  4681 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4682 \<gg> to \<ggreater>;
  4683 
  4684 
  4685 *** Document preparation ***
  4686 
  4687 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4688 available: are "it" for near math-mode best-style output, "sl" for
  4689 slanted text style, and "tt" for plain type-writer; if no
  4690 \isabellestyle command is given, output is according to slanted
  4691 type-writer);
  4692 
  4693 * support sub/super scripts (for single symbols only), input syntax is
  4694 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4695 
  4696 * some more standard symbols; see Appendix A of the system manual for
  4697 the complete list of symbols defined in isabellesym.sty;
  4698 
  4699 * improved isabelle style files; more abstract symbol implementation
  4700 (should now use \isamath{...} and \isatext{...} in custom symbol
  4701 definitions);
  4702 
  4703 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4704 state; Note that presentation of goal states does not conform to
  4705 actual human-readable proof documents.  Please do not include goal
  4706 states into document output unless you really know what you are doing!
  4707 
  4708 * proper indentation of antiquoted output with proportional LaTeX
  4709 fonts;
  4710 
  4711 * no_document ML operator temporarily disables LaTeX document
  4712 generation;
  4713 
  4714 * isatool unsymbolize tunes sources for plain ASCII communication;
  4715 
  4716 
  4717 *** Isar ***
  4718 
  4719 * Pure: Isar now suffers initial goal statements to contain unbound
  4720 schematic variables (this does not conform to actual readable proof
  4721 documents, due to unpredictable outcome and non-compositional proof
  4722 checking); users who know what they are doing may use schematic goals
  4723 for Prolog-style synthesis of proven results;
  4724 
  4725 * Pure: assumption method (an implicit finishing) now handles actual
  4726 rules as well;
  4727 
  4728 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4729 initial goal, declare "that" only as Pure intro (only for single
  4730 steps); the "that" rule assumption may now be involved in implicit
  4731 finishing, thus ".." becomes a feasible for trivial obtains;
  4732 
  4733 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4734 instance proofs may be performed by "..";
  4735 
  4736 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4737 statements as well;
  4738 
  4739 * Pure: more robust selection of calculational rules;
  4740 
  4741 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4742 rule (as well as the assumption rule);
  4743 
  4744 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4745 lemmas, using the graph browser tool;
  4746 
  4747 * Pure: predict failure of "show" in interactive mode;
  4748 
  4749 * Pure: 'thms_containing' now takes actual terms as arguments;
  4750 
  4751 * HOL: improved method 'induct' --- now handles non-atomic goals
  4752 (potential INCOMPATIBILITY); tuned error handling;
  4753 
  4754 * HOL: cases and induct rules now provide explicit hints about the
  4755 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4756 any remaining facts are inserted into the goal verbatim;
  4757 
  4758 * HOL: local contexts (aka cases) may now contain term bindings as
  4759 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4760 the result to be shown in each case;
  4761 
  4762 * HOL: added 'recdef_tc' command;
  4763 
  4764 * isatool convert assists in eliminating legacy ML scripts;
  4765 
  4766 
  4767 *** HOL ***
  4768 
  4769 * HOL/Library: a collection of generic theories to be used together
  4770 with main HOL; the theory loader path already includes this directory
  4771 by default; the following existing theories have been moved here:
  4772 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4773 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4774 
  4775 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4776 modelling and verification task performed in Isabelle/HOL +
  4777 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4778 
  4779 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4780 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4781 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4782 'domain', this makes the theory consistent with mathematical
  4783 literature;
  4784 
  4785 * HOL basics: added overloaded operations "inverse" and "divide"
  4786 (infix "/"), syntax for generic "abs" operation, generic summation
  4787 operator \<Sum>;
  4788 
  4789 * HOL/typedef: simplified package, provide more useful rules (see also
  4790 HOL/subset.thy);
  4791 
  4792 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4793 now expressed as a proper nested rule (old-style tactic scripts may
  4794 require atomize_strip_tac to cope with non-atomic premises);
  4795 
  4796 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4797 to "split_conv" (old name still available for compatibility);
  4798 
  4799 * HOL: improved concrete syntax for strings (e.g. allows translation
  4800 rules with string literals);
  4801 
  4802 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4803  and Fleuriot's mechanization of analysis, including the transcendental
  4804  functions for the reals;
  4805 
  4806 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4807 
  4808 
  4809 *** CTT ***
  4810 
  4811 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4812 "lam" is displayed as TWO lambda-symbols
  4813 
  4814 * CTT: theory Main now available, containing everything (that is, Bool
  4815 and Arith);
  4816 
  4817 
  4818 *** General ***
  4819 
  4820 * Pure: the Simplifier has been implemented properly as a derived rule
  4821 outside of the actual kernel (at last!); the overall performance
  4822 penalty in practical applications is about 50%, while reliability of
  4823 the Isabelle inference kernel has been greatly improved;
  4824 
  4825 * print modes "brackets" and "no_brackets" control output of nested =>
  4826 (types) and ==> (props); the default behaviour is "brackets";
  4827 
  4828 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4829 as assumptions as well;
  4830 
  4831 * system: support Poly/ML 4.0;
  4832 
  4833 * system: isatool install handles KDE version 1 or 2;
  4834 
  4835 
  4836 
  4837 New in Isabelle99-1 (October 2000)
  4838 ----------------------------------
  4839 
  4840 *** Overview of INCOMPATIBILITIES ***
  4841 
  4842 * HOL: simplification of natural numbers is much changed; to partly
  4843 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4844 issue the following ML commands:
  4845 
  4846   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4847   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4848 
  4849 * HOL: simplification no longer dives into case-expressions; this is
  4850 controlled by "t.weak_case_cong" for each datatype t;
  4851 
  4852 * HOL: nat_less_induct renamed to less_induct;
  4853 
  4854 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4855 fixsome to patch .thy and .ML sources automatically;
  4856 
  4857   select_equality  -> some_equality
  4858   select_eq_Ex     -> some_eq_ex
  4859   selectI2EX       -> someI2_ex
  4860   selectI2         -> someI2
  4861   selectI          -> someI
  4862   select1_equality -> some1_equality
  4863   Eps_sym_eq       -> some_sym_eq_trivial
  4864   Eps_eq           -> some_eq_trivial
  4865 
  4866 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4867 
  4868 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4869 instead);
  4870 
  4871 * HOL: the recursion equations generated by 'recdef' are now called
  4872 f.simps instead of f.rules;
  4873 
  4874 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4875 
  4876 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4877 sometimes be needed;
  4878 
  4879 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4880 
  4881 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4882 
  4883 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4884 product is now "<*>" instead of "Times"; the lexicographic product is
  4885 now "<*lex*>" instead of "**";
  4886 
  4887 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4888 of main HOL, but was unused); better use HOL's datatype package;
  4889 
  4890 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4891 the old syntax may be recovered as follows:
  4892 
  4893   syntax (symbols)
  4894     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4895       (infixl "\\<oplus>" 100)
  4896 
  4897 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4898 
  4899 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4900 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4901 internally;
  4902 
  4903 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4904 changed from A/r to A//r;
  4905 
  4906 * ZF: new treatment of arithmetic (nat & int) may break some old
  4907 proofs;
  4908 
  4909 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4910 rulify -> rule_format, elimify -> elim_format, ...);
  4911 
  4912 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4913 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4914 should have to change intro!! to intro? only); replaced "delrule" by
  4915 "rule del";
  4916 
  4917 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4918 
  4919 * Provers: strengthened force_tac by using new first_best_tac;
  4920 
  4921 * LaTeX document preparation: several changes of isabelle.sty (see
  4922 lib/texinputs);
  4923 
  4924 
  4925 *** Document preparation ***
  4926 
  4927 * formal comments (text blocks etc.) in new-style theories may now
  4928 contain antiquotations of thm/prop/term/typ/text to be presented
  4929 according to latex print mode; concrete syntax is like this:
  4930 @{term[show_types] "f(x) = a + x"};
  4931 
  4932 * isatool mkdir provides easy setup of Isabelle session directories,
  4933 including proper document sources;
  4934 
  4935 * generated LaTeX sources are now deleted after successful run
  4936 (isatool document -c); may retain a copy somewhere else via -D option
  4937 of isatool usedir;
  4938 
  4939 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4940 style files, achieving self-contained LaTeX sources and simplifying
  4941 LaTeX debugging;
  4942 
  4943 * old-style theories now produce (crude) LaTeX output as well;
  4944 
  4945 * browser info session directories are now self-contained (may be put
  4946 on WWW server seperately); improved graphs of nested sessions; removed
  4947 graph for 'all sessions';
  4948 
  4949 * several improvements in isabelle style files; \isabellestyle{it}
  4950 produces fake math mode output; \isamarkupheader is now \section by
  4951 default; see lib/texinputs/isabelle.sty etc.;
  4952 
  4953 
  4954 *** Isar ***
  4955 
  4956 * Isar/Pure: local results and corresponding term bindings are now
  4957 subject to Hindley-Milner polymorphism (similar to ML); this
  4958 accommodates incremental type-inference very nicely;
  4959 
  4960 * Isar/Pure: new derived language element 'obtain' supports
  4961 generalized existence reasoning;
  4962 
  4963 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4964 support accumulation of results, without applying any rules yet;
  4965 useful to collect intermediate results without explicit name
  4966 references, and for use with transitivity rules with more than 2
  4967 premises;
  4968 
  4969 * Isar/Pure: scalable support for case-analysis type proofs: new
  4970 'case' language element refers to local contexts symbolically, as
  4971 produced by certain proof methods; internally, case names are attached
  4972 to theorems as "tags";
  4973 
  4974 * Isar/Pure: theory command 'hide' removes declarations from
  4975 class/type/const name spaces;
  4976 
  4977 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4978 indicate potential overloading;
  4979 
  4980 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4981 
  4982 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4983 "{a,b,c}" instead of {a,b,c};
  4984 
  4985 * Isar/Pure now provides its own version of intro/elim/dest
  4986 attributes; useful for building new logics, but beware of confusion
  4987 with the version in Provers/classical;
  4988 
  4989 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4990 case name 'antecedent';
  4991 
  4992 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4993 to the current context is now done automatically);
  4994 
  4995 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4996 for definining proof methods in ML;
  4997 
  4998 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4999 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5000 most cases, one should have to change intro!! to intro? only);
  5001 replaced "delrule" by "rule del";
  5002 
  5003 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5004 'symmetric' attribute (the latter supercedes [RS sym]);
  5005 
  5006 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5007 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5008 well (including splits);
  5009 
  5010 * Isar/Provers: Simplifier and Classical methods now support all kind
  5011 of modifiers used in the past, including 'cong', 'iff', etc.
  5012 
  5013 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5014 of Simplifier and Classical reasoner);
  5015 
  5016 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5017 now support named cases; major packages (inductive, datatype, primrec,
  5018 recdef) support case names and properly name parameters;
  5019 
  5020 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5021 monotonicity conditions are extracted to be proven at end of
  5022 calculations;
  5023 
  5024 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5025 method anyway;
  5026 
  5027 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5028 split_if split_if_asm; datatype package provides theorems foo.splits =
  5029 foo.split foo.split_asm for each datatype;
  5030 
  5031 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5032 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5033 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5034 use "(cases (simplified))" method in proper proof texts);
  5035 
  5036 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5037 
  5038 * Isar: names of theorems etc. may be natural numbers as well;
  5039 
  5040 * Isar: 'pr' command: optional arguments for goals_limit and
  5041 ProofContext.prems_limit; no longer prints theory contexts, but only
  5042 proof states;
  5043 
  5044 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5045 additional print modes to be specified; e.g. "pr(latex)" will print
  5046 proof state according to the Isabelle LaTeX style;
  5047 
  5048 * Isar: improved support for emulating tactic scripts, including proof
  5049 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5050 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5051 (for HOL datatypes);
  5052 
  5053 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5054 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5055 'proof method scripts' have to be in depth-first order;
  5056 
  5057 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5058 
  5059 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5060 should instead use individual commands for printing items
  5061 (print_commands, print_methods etc.);
  5062 
  5063 * Isar: added 'nothing' --- the empty list of theorems;
  5064 
  5065 
  5066 *** HOL ***
  5067 
  5068 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5069 corresponding virtual machine and a specification of its bytecode
  5070 verifier and a lightweight bytecode verifier, including proofs of
  5071 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5072 Cornelia Pusch (see also the homepage of project Bali at
  5073 http://isabelle.in.tum.de/Bali/);
  5074 
  5075 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5076 Clemens Ballarin;
  5077 
  5078 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5079 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5080 Rasmussen;
  5081 
  5082 * HOL/Lattice: fundamental concepts of lattice theory and order
  5083 structures, including duals, properties of bounds versus algebraic
  5084 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5085 Theorem for complete lattices etc.; may also serve as a demonstration
  5086 for abstract algebraic reasoning using axiomatic type classes, and
  5087 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5088 
  5089 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5090 von Oheimb;
  5091 
  5092 * HOL/IMPP: extension of IMP with local variables and mutually
  5093 recursive procedures, by David von Oheimb;
  5094 
  5095 * HOL/Lambda: converted into new-style theory and document;
  5096 
  5097 * HOL/ex/Multiquote: example of multiple nested quotations and
  5098 anti-quotations -- basically a generalized version of de-Bruijn
  5099 representation; very useful in avoiding lifting of operations;
  5100 
  5101 * HOL/record: added general record equality rule to simpset; fixed
  5102 select-update simplification procedure to handle extended records as
  5103 well; admit "r" as field name;
  5104 
  5105 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5106 other numeric types and also as the identity of groups, rings, etc.;
  5107 
  5108 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5109 Types nat and int belong to this axclass;
  5110 
  5111 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5112    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5113    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5114   two terms #m*u and #n*u are replaced by #(m+n)*u
  5115     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5116   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5117     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5118 
  5119 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5120 powerful prover for predicate logic but knows nothing of clasets; see
  5121 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5122 
  5123 * HOL: new version of "case_tac" subsumes both boolean case split and
  5124 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5125 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5126 
  5127 * HOL: simplification no longer dives into case-expressions: only the
  5128 selector expression is simplified, but not the remaining arms; to
  5129 enable full simplification of case-expressions for datatype t, you may
  5130 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5131 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5132 
  5133 * HOL/recdef: the recursion equations generated by 'recdef' for
  5134 function 'f' are now called f.simps instead of f.rules; if all
  5135 termination conditions are proved automatically, these simplification
  5136 rules are added to the simpset, as in primrec; rules may be named
  5137 individually as well, resulting in a separate list of theorems for
  5138 each equation;
  5139 
  5140 * HOL/While is a new theory that provides a while-combinator. It
  5141 permits the definition of tail-recursive functions without the
  5142 provision of a termination measure. The latter is necessary once the
  5143 invariant proof rule for while is applied.
  5144 
  5145 * HOL: new (overloaded) notation for the set of elements below/above
  5146 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5147 
  5148 * HOL: theorems impI, allI, ballI bound as "strip";
  5149 
  5150 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5151 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5152 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5153 
  5154 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5155 
  5156 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5157 main HOL, but was unused);
  5158 
  5159 * HOL: fewer consts declared as global (e.g. have to refer to
  5160 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5161 
  5162 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5163 in case of overlap with user translations (e.g. judgements over
  5164 tuples); (note that the underlying logical represenation is still
  5165 bogus);
  5166 
  5167 
  5168 *** ZF ***
  5169 
  5170 * ZF: simplification automatically cancels common terms in arithmetic
  5171 expressions over nat and int;
  5172 
  5173 * ZF: new treatment of nat to minimize type-checking: all operators
  5174 coerce their operands to a natural number using the function natify,
  5175 making the algebraic laws unconditional;
  5176 
  5177 * ZF: as above, for int: operators coerce their operands to an integer
  5178 using the function intify;
  5179 
  5180 * ZF: the integer library now contains many of the usual laws for the
  5181 orderings, including $<=, and monotonicity laws for $+ and $*;
  5182 
  5183 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5184 simplification;
  5185 
  5186 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5187 to the simplifier and classical reasoner simultaneously;
  5188 
  5189 
  5190 *** General ***
  5191 
  5192 * Provers: blast_tac now handles actual object-logic rules as
  5193 assumptions; note that auto_tac uses blast_tac internally as well;
  5194 
  5195 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5196 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5197 
  5198 * Provers: delrules now handles destruct rules as well (no longer need
  5199 explicit make_elim);
  5200 
  5201 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5202   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5203 use instead the strong form,
  5204   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5205 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5206 from destruct-rules;
  5207 
  5208 * Provers: Simplifier.easy_setup provides a fast path to basic
  5209 Simplifier setup for new object-logics;
  5210 
  5211 * Pure: AST translation rules no longer require constant head on LHS;
  5212 
  5213 * Pure: improved name spaces: ambiguous output is qualified; support
  5214 for hiding of names;
  5215 
  5216 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5217 XSYMBOL_HOME; no longer need to do manual configuration in most
  5218 situations;
  5219 
  5220 * system: compression of ML heaps images may now be controlled via -c
  5221 option of isabelle and isatool usedir (currently only observed by
  5222 Poly/ML);
  5223 
  5224 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5225 useful for remote X11);
  5226 
  5227 * system: provide TAGS file for Isabelle sources;
  5228 
  5229 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5230 order;
  5231 
  5232 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5233 timing flag supersedes proof_timing and Toplevel.trace;
  5234 
  5235 * ML: new combinators |>> and |>>> for incremental transformations
  5236 with secondary results (e.g. certain theory extensions):
  5237 
  5238 * ML: PureThy.add_defs gets additional argument to indicate potential
  5239 overloading (usually false);
  5240 
  5241 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5242 results;
  5243 
  5244 
  5245 
  5246 New in Isabelle99 (October 1999)
  5247 --------------------------------
  5248 
  5249 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5250 
  5251 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5252 are no longer simplified.  (This allows the simplifier to unfold recursive
  5253 functional programs.)  To restore the old behaviour, declare
  5254 
  5255     Delcongs [if_weak_cong];
  5256 
  5257 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5258 complement;
  5259 
  5260 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5261 
  5262 * HOL/datatype: mutual_induct_tac no longer exists --
  5263   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5264 
  5265 * HOL/typedef: fixed type inference for representing set; type
  5266 arguments now have to occur explicitly on the rhs as type constraints;
  5267 
  5268 * ZF: The con_defs part of an inductive definition may no longer refer
  5269 to constants declared in the same theory;
  5270 
  5271 * HOL, ZF: the function mk_cases, generated by the inductive
  5272 definition package, has lost an argument.  To simplify its result, it
  5273 uses the default simpset instead of a supplied list of theorems.
  5274 
  5275 * HOL/List: the constructors of type list are now Nil and Cons;
  5276 
  5277 * Simplifier: the type of the infix ML functions
  5278         setSSolver addSSolver setSolver addSolver
  5279 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5280 for packaging solvers. A solver is created via
  5281         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5282 where the string argument is only a comment.
  5283 
  5284 
  5285 *** Proof tools ***
  5286 
  5287 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5288 decision procedure for linear arithmetic. Currently it is used for
  5289 types `nat', `int', and `real' in HOL (see below); it can, should and
  5290 will be instantiated for other types and logics as well.
  5291 
  5292 * The simplifier now accepts rewrite rules with flexible heads, eg
  5293      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5294   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5295   matching.
  5296 
  5297 
  5298 *** General ***
  5299 
  5300 * New Isabelle/Isar subsystem provides an alternative to traditional
  5301 tactical theorem proving; together with the ProofGeneral/isar user
  5302 interface it offers an interactive environment for developing human
  5303 readable proof documents (Isar == Intelligible semi-automated
  5304 reasoning); for further information see isatool doc isar-ref,
  5305 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5306 
  5307 * improved and simplified presentation of theories: better HTML markup
  5308 (including colors), graph views in several sizes; isatool usedir now
  5309 provides a proper interface for user theories (via -P option); actual
  5310 document preparation based on (PDF)LaTeX is available as well (for
  5311 new-style theories only); see isatool doc system for more information;
  5312 
  5313 * native support for Proof General, both for classic Isabelle and
  5314 Isabelle/Isar;
  5315 
  5316 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5317 using the graph browser tool;
  5318 
  5319 * Isabelle manuals now also available as PDF;
  5320 
  5321 * theory loader rewritten from scratch (may not be fully
  5322 bug-compatible); old loadpath variable has been replaced by show_path,
  5323 add_path, del_path, reset_path functions; new operations such as
  5324 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5325 isatool doc ref);
  5326 
  5327 * improved isatool install: option -k creates KDE application icon,
  5328 option -p DIR installs standalone binaries;
  5329 
  5330 * added ML_PLATFORM setting (useful for cross-platform installations);
  5331 more robust handling of platform specific ML images for SML/NJ;
  5332 
  5333 * the settings environment is now statically scoped, i.e. it is never
  5334 created again in sub-processes invoked from isabelle, isatool, or
  5335 Isabelle;
  5336 
  5337 * path element specification '~~' refers to '$ISABELLE_HOME';
  5338 
  5339 * in locales, the "assumes" and "defines" parts may be omitted if
  5340 empty;
  5341 
  5342 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5343 long arrows);
  5344 
  5345 * new print_mode "HTML";
  5346 
  5347 * new flag show_tags controls display of tags of theorems (which are
  5348 basically just comments that may be attached by some tools);
  5349 
  5350 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5351 mode and goal output format:
  5352 
  5353 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5354 244c244
  5355 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5356 ---
  5357 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5358 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5359 181c181
  5360 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5361 ---
  5362 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5363 
  5364 * function bind_thms stores lists of theorems (cf. bind_thm);
  5365 
  5366 * new shorthand tactics ftac, eatac, datac, fatac;
  5367 
  5368 * qed (and friends) now accept "" as result name; in that case the
  5369 theorem is not stored, but proper checks and presentation of the
  5370 result still apply;
  5371 
  5372 * theorem database now also indexes constants "Trueprop", "all",
  5373 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5374 
  5375 
  5376 *** HOL ***
  5377 
  5378 ** HOL arithmetic **
  5379 
  5380 * There are now decision procedures for linear arithmetic over nat and
  5381 int:
  5382 
  5383 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5384 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5385 are treated as atomic; subformulae not involving type `nat' or `int'
  5386 are ignored; quantified subformulae are ignored unless they are
  5387 positive universal or negative existential. The tactic has to be
  5388 invoked by hand and can be a little bit slow. In particular, the
  5389 running time is exponential in the number of occurrences of `min' and
  5390 `max', and `-' on `nat'.
  5391 
  5392 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5393 (negated) (in)equalities among the premises and the conclusion into
  5394 account (i.e. no compound formulae) and does not know about `min' and
  5395 `max', and `-' on `nat'. It is fast and is used automatically by the
  5396 simplifier.
  5397 
  5398 NB: At the moment, these decision procedures do not cope with mixed
  5399 nat/int formulae where the two parts interact, such as `m < n ==>
  5400 int(m) < int(n)'.
  5401 
  5402 * HOL/Numeral provides a generic theory of numerals (encoded
  5403 efficiently as bit strings); setup for types nat/int/real is in place;
  5404 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5405 int, existing theories and proof scripts may require a few additional
  5406 type constraints;
  5407 
  5408 * integer division and remainder can now be performed on constant
  5409 arguments;
  5410 
  5411 * many properties of integer multiplication, division and remainder
  5412 are now available;
  5413 
  5414 * An interface to the Stanford Validity Checker (SVC) is available through the
  5415 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5416 are proved automatically.  SVC must be installed separately, and its results
  5417 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5418 invocation of the underlying oracle).  For SVC see
  5419   http://verify.stanford.edu/SVC
  5420 
  5421 * IsaMakefile: the HOL-Real target now builds an actual image;
  5422 
  5423 
  5424 ** HOL misc **
  5425 
  5426 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5427 (in Isabelle/Isar) -- by Gertrud Bauer;
  5428 
  5429 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5430 analysis for assembly languages with subtypes;
  5431 
  5432 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5433 -- avoids syntactic ambiguities and treats state, transition, and
  5434 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5435 changed syntax and (many) tactics;
  5436 
  5437 * HOL/inductive: Now also handles more general introduction rules such
  5438   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5439   theorems are now maintained within the theory (maintained via the
  5440   "mono" attribute);
  5441 
  5442 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5443   (using function types) such as
  5444 
  5445   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5446 
  5447 * HOL/record: record_simproc (part of the default simpset) takes care
  5448 of selectors applied to updated records; record_split_tac is no longer
  5449 part of the default claset; update_defs may now be removed from the
  5450 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5451 
  5452   claset_ref () := claset() addSWrapper record_split_wrapper;
  5453   Delsimprocs [record_simproc]
  5454 
  5455 * HOL/typedef: fixed type inference for representing set; type
  5456 arguments now have to occur explicitly on the rhs as type constraints;
  5457 
  5458 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5459 names rather than an ML expression;
  5460 
  5461 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5462 supplied later.  Program schemes can be defined, such as
  5463     "While B C s = (if B s then While B C (C s) else s)"
  5464 where the well-founded relation can be chosen after B and C have been given.
  5465 
  5466 * HOL/List: the constructors of type list are now Nil and Cons;
  5467 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5468 course, ML tools referring to List.list.op # etc. have to be adapted;
  5469 
  5470 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5471 disabled by default; run isabelle with option -m HOL to get back to
  5472 the original Gordon/HOL-style output;
  5473 
  5474 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5475 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5476 
  5477 * HOL basic syntax simplified (more orthogonal): all variants of
  5478 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5479 Eps operator is provided as well: "SOME x. P[x]";
  5480 
  5481 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5482 
  5483 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5484 thus available for user theories;
  5485 
  5486 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5487 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5488 time;
  5489 
  5490 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5491 several times and then mp;
  5492 
  5493 
  5494 *** LK ***
  5495 
  5496 * the notation <<...>> is now available as a notation for sequences of
  5497 formulas;
  5498 
  5499 * the simplifier is now installed
  5500 
  5501 * the axiom system has been generalized (thanks to Soren Heilmann)
  5502 
  5503 * the classical reasoner now has a default rule database
  5504 
  5505 
  5506 *** ZF ***
  5507 
  5508 * new primrec section allows primitive recursive functions to be given
  5509 directly (as in HOL) over datatypes and the natural numbers;
  5510 
  5511 * new tactics induct_tac and exhaust_tac for induction (or case
  5512 analysis) over datatypes and the natural numbers;
  5513 
  5514 * the datatype declaration of type T now defines the recursor T_rec;
  5515 
  5516 * simplification automatically does freeness reasoning for datatype
  5517 constructors;
  5518 
  5519 * automatic type-inference, with AddTCs command to insert new
  5520 type-checking rules;
  5521 
  5522 * datatype introduction rules are now added as Safe Introduction rules
  5523 to the claset;
  5524 
  5525 * the syntax "if P then x else y" is now available in addition to
  5526 if(P,x,y);
  5527 
  5528 
  5529 *** Internal programming interfaces ***
  5530 
  5531 * tuned simplifier trace output; new flag debug_simp;
  5532 
  5533 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5534 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5535 
  5536 * AxClass.axclass_tac lost the theory argument;
  5537 
  5538 * tuned current_goals_markers semantics: begin / end goal avoids
  5539 printing empty lines;
  5540 
  5541 * removed prs and prs_fn hook, which was broken because it did not
  5542 include \n in its semantics, forcing writeln to add one
  5543 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5544 string -> unit if you really want to output text without newline;
  5545 
  5546 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5547 plain output, interface builders may have to enable 'isabelle_font'
  5548 mode to get Isabelle font glyphs as before;
  5549 
  5550 * refined token_translation interface; INCOMPATIBILITY: output length
  5551 now of type real instead of int;
  5552 
  5553 * theory loader actions may be traced via new ThyInfo.add_hook
  5554 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5555 your own database of information attached to *whole* theories -- as
  5556 opposed to intra-theory data slots offered via TheoryDataFun;
  5557 
  5558 * proper handling of dangling sort hypotheses (at last!);
  5559 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5560 extra sort hypotheses that can be witnessed from the type signature;
  5561 the force_strip_shyps flag is gone, any remaining shyps are simply
  5562 left in the theorem (with a warning issued by strip_shyps_warning);
  5563 
  5564 
  5565 
  5566 New in Isabelle98-1 (October 1998)
  5567 ----------------------------------
  5568 
  5569 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5570 
  5571 * several changes of automated proof tools;
  5572 
  5573 * HOL: major changes to the inductive and datatype packages, including
  5574 some minor incompatibilities of theory syntax;
  5575 
  5576 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5577 called `inj_on';
  5578 
  5579 * HOL: removed duplicate thms in Arith:
  5580   less_imp_add_less  should be replaced by  trans_less_add1
  5581   le_imp_add_le      should be replaced by  trans_le_add1
  5582 
  5583 * HOL: unary minus is now overloaded (new type constraints may be
  5584 required);
  5585 
  5586 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5587 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5588 now taken as an integer constant.
  5589 
  5590 * Pure: ML function 'theory_of' renamed to 'theory';
  5591 
  5592 
  5593 *** Proof tools ***
  5594 
  5595 * Simplifier:
  5596   1. Asm_full_simp_tac is now more aggressive.
  5597      1. It will sometimes reorient premises if that increases their power to
  5598         simplify.
  5599      2. It does no longer proceed strictly from left to right but may also
  5600         rotate premises to achieve further simplification.
  5601      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5602      old Asm_full_simp_tac in that it does not rotate premises.
  5603   2. The simplifier now knows a little bit about nat-arithmetic.
  5604 
  5605 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5606 allows for selected deletion of wrappers, by introduction of names for
  5607 wrapper functionals.  This implies that addbefore, addSbefore,
  5608 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5609 and that adding two tactics with the same name overwrites the first
  5610 one (emitting a warning).
  5611   type wrapper = (int -> tactic) -> (int -> tactic)
  5612   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5613   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5614   delWrapper, delSWrapper: claset *  string            -> claset
  5615   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5616 
  5617 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5618 semantics; addbefore now affects only the unsafe part of step_tac
  5619 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5620 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5621 by Force_tac;
  5622 
  5623 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5624 compWrapper; added safe wrapper (and access functions for it);
  5625 
  5626 * HOL/split_all_tac is now much faster and fails if there is nothing
  5627 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5628 and the names of the automatically generated variables have changed.
  5629 split_all_tac has moved within claset() from unsafe wrappers to safe
  5630 wrappers, which means that !!-bound variables are split much more
  5631 aggressively, and safe_tac and clarify_tac now split such variables.
  5632 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5633 Note: the same holds for record_split_tac, which does the job of
  5634 split_all_tac for record fields.
  5635 
  5636 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5637 permanently to the default simpset using Addsplits just like
  5638 Addsimps. They can be removed via Delsplits just like
  5639 Delsimps. Lower-case versions are also available.
  5640 
  5641 * HOL/Simplifier: The rule split_if is now part of the default
  5642 simpset. This means that the simplifier will eliminate all occurrences
  5643 of if-then-else in the conclusion of a goal. To prevent this, you can
  5644 either remove split_if completely from the default simpset by
  5645 `Delsplits [split_if]' or remove it in a specific call of the
  5646 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5647 other case splitting rules to/from the default simpset: every datatype
  5648 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5649 t is the name of the datatype).
  5650 
  5651 * Classical reasoner / Simplifier combination: new force_tac (and
  5652 derivatives Force_tac, force) combines rewriting and classical
  5653 reasoning (and whatever other tools) similarly to auto_tac, but is
  5654 aimed to solve the given subgoal completely.
  5655 
  5656 
  5657 *** General ***
  5658 
  5659 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5660 and `goalw': the theory is no longer needed as an explicit argument -
  5661 the current theory context is used; assumptions are no longer returned
  5662 at the ML-level unless one of them starts with ==> or !!; it is
  5663 recommended to convert to these new commands using isatool fixgoal
  5664 (backup your sources first!);
  5665 
  5666 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5667 the current theory context, and 'theory' to lookup stored theories;
  5668 
  5669 * new theory section 'locale' for declaring constants, assumptions and
  5670 definitions that have local scope;
  5671 
  5672 * new theory section 'nonterminals' for purely syntactic types;
  5673 
  5674 * new theory section 'setup' for generic ML setup functions
  5675 (e.g. package initialization);
  5676 
  5677 * the distribution now includes Isabelle icons: see
  5678 lib/logo/isabelle-{small,tiny}.xpm;
  5679 
  5680 * isatool install - install binaries with absolute references to
  5681 ISABELLE_HOME/bin;
  5682 
  5683 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5684 
  5685 * print mode 'emacs' reserved for Isamode;
  5686 
  5687 * support multiple print (ast) translations per constant name;
  5688 
  5689 * theorems involving oracles are now printed with a suffixed [!];
  5690 
  5691 
  5692 *** HOL ***
  5693 
  5694 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5695 
  5696 * HOL/inductive package reorganized and improved: now supports mutual
  5697 definitions such as
  5698 
  5699   inductive EVEN ODD
  5700     intrs
  5701       null "0 : EVEN"
  5702       oddI "n : EVEN ==> Suc n : ODD"
  5703       evenI "n : ODD ==> Suc n : EVEN"
  5704 
  5705 new theorem list "elims" contains an elimination rule for each of the
  5706 recursive sets; inductive definitions now handle disjunctive premises
  5707 correctly (also ZF);
  5708 
  5709 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5710 "mutual_induct" no longer exists - the induction rule is always
  5711 contained in "induct";
  5712 
  5713 
  5714 * HOL/datatype package re-implemented and greatly improved: now
  5715 supports mutually recursive datatypes such as
  5716 
  5717   datatype
  5718     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5719             | SUM ('a aexp) ('a aexp)
  5720             | DIFF ('a aexp) ('a aexp)
  5721             | NUM 'a
  5722   and
  5723     'a bexp = LESS ('a aexp) ('a aexp)
  5724             | AND ('a bexp) ('a bexp)
  5725             | OR ('a bexp) ('a bexp)
  5726 
  5727 as well as indirectly recursive datatypes such as
  5728 
  5729   datatype
  5730     ('a, 'b) term = Var 'a
  5731                   | App 'b ((('a, 'b) term) list)
  5732 
  5733 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5734 induction on mutually / indirectly recursive datatypes.
  5735 
  5736 Primrec equations are now stored in theory and can be accessed via
  5737 <function_name>.simps.
  5738 
  5739 INCOMPATIBILITIES:
  5740 
  5741   - Theories using datatypes must now have theory Datatype as an
  5742     ancestor.
  5743   - The specific <typename>.induct_tac no longer exists - use the
  5744     generic induct_tac instead.
  5745   - natE has been renamed to nat.exhaust - use exhaust_tac
  5746     instead of res_inst_tac ... natE. Note that the variable
  5747     names in nat.exhaust differ from the names in natE, this
  5748     may cause some "fragile" proofs to fail.
  5749   - The theorems split_<typename>_case and split_<typename>_case_asm
  5750     have been renamed to <typename>.split and <typename>.split_asm.
  5751   - Since default sorts of type variables are now handled correctly,
  5752     some datatype definitions may have to be annotated with explicit
  5753     sort constraints.
  5754   - Primrec definitions no longer require function name and type
  5755     of recursive argument.
  5756 
  5757 Consider using isatool fixdatatype to adapt your theories and proof
  5758 scripts to the new package (backup your sources first!).
  5759 
  5760 
  5761 * HOL/record package: considerably improved implementation; now
  5762 includes concrete syntax for record types, terms, updates; theorems
  5763 for surjective pairing and splitting !!-bound record variables; proof
  5764 support is as follows:
  5765 
  5766   1) standard conversions (selectors or updates applied to record
  5767 constructor terms) are part of the standard simpset;
  5768 
  5769   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5770 made part of standard simpset and claset via addIffs;
  5771 
  5772   3) a tactic for record field splitting (record_split_tac) is part of
  5773 the standard claset (addSWrapper);
  5774 
  5775 To get a better idea about these rules you may retrieve them via
  5776 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5777 the name of your record type.
  5778 
  5779 The split tactic 3) conceptually simplifies by the following rule:
  5780 
  5781   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5782 
  5783 Thus any record variable that is bound by meta-all will automatically
  5784 blow up into some record constructor term, consequently the
  5785 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5786 solve record problems automatically.
  5787 
  5788 
  5789 * reorganized the main HOL image: HOL/Integ and String loaded by
  5790 default; theory Main includes everything;
  5791 
  5792 * automatic simplification of integer sums and comparisons, using cancellation;
  5793 
  5794 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5795 
  5796 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5797 
  5798 * many new identities for unions, intersections, set difference, etc.;
  5799 
  5800 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5801 called split_if, split_split, split_sum_case and split_nat_case (to go
  5802 with add/delsplits);
  5803 
  5804 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5805 (?x::unit) = (); this is made part of the default simpset, which COULD
  5806 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5807 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5808 unit_abs_eta_conv is added in order to counter the effect of
  5809 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5810 %u.f();
  5811 
  5812 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5813 makes more sense);
  5814 
  5815 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5816   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5817   disjointness reasoning but breaking a few old proofs.
  5818 
  5819 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5820 to 'converse' from 'inverse' (for compatibility with ZF and some
  5821 literature);
  5822 
  5823 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5824 the well-founded relation;
  5825 
  5826 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5827     Compl A.  The "Compl" syntax remains available as input syntax for this
  5828     release ONLY.
  5829 
  5830 * HOL/Update: new theory of function updates:
  5831     f(a:=b) == %x. if x=a then b else f x
  5832 may also be iterated as in f(a:=b,c:=d,...);
  5833 
  5834 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5835 
  5836 * HOL/List:
  5837   - new function list_update written xs[i:=v] that updates the i-th
  5838     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5839   - new function `upt' written [i..j(] which generates the list
  5840     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5841     bound write [i..j], which is a shorthand for [i..j+1(].
  5842   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5843 
  5844 * HOL/Arith:
  5845   - removed 'pred' (predecessor) function;
  5846   - generalized some theorems about n-1;
  5847   - many new laws about "div" and "mod";
  5848   - new laws about greatest common divisors (see theory ex/Primes);
  5849 
  5850 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5851 instead of "inverse";
  5852 
  5853 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5854   of the multiset ordering;
  5855 
  5856 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5857   (not included by default);
  5858 
  5859 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5860 
  5861 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5862   programs, i.e. different program variables may have different types.
  5863 
  5864 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5865   [previously, this check worked only if the rewrite rule was unconditional]
  5866   Now rew can involve either definitions or equalities (either == or =).
  5867 
  5868 
  5869 *** ZF ***
  5870 
  5871 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5872   only the theorems proved on ZF.ML;
  5873 
  5874 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5875   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5876   disjointness reasoning but breaking a few old proofs.
  5877 
  5878 * ZF/Update: new theory of function updates
  5879     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5880   may also be iterated as in f(a:=b,c:=d,...);
  5881 
  5882 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5883 
  5884 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5885   [previously, this check worked only if the rewrite rule was unconditional]
  5886   Now rew can involve either definitions or equalities (either == or =).
  5887 
  5888 * case_tac provided for compatibility with HOL
  5889     (like the old excluded_middle_tac, but with subgoals swapped)
  5890 
  5891 
  5892 *** Internal programming interfaces ***
  5893 
  5894 * Pure: several new basic modules made available for general use, see
  5895 also src/Pure/README;
  5896 
  5897 * improved the theory data mechanism to support encapsulation (data
  5898 kind name replaced by private Object.kind, acting as authorization
  5899 key); new type-safe user interface via functor TheoryDataFun; generic
  5900 print_data function becomes basically useless;
  5901 
  5902 * removed global_names compatibility flag -- all theory declarations
  5903 are qualified by default;
  5904 
  5905 * module Pure/Syntax now offers quote / antiquote translation
  5906 functions (useful for Hoare logic etc. with implicit dependencies);
  5907 see HOL/ex/Antiquote for an example use;
  5908 
  5909 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5910 cterm -> thm;
  5911 
  5912 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5913 subgoal;
  5914 
  5915 * Display.print_goals function moved to Locale.print_goals;
  5916 
  5917 * standard print function for goals supports current_goals_markers
  5918 variable for marking begin of proof, end of proof, start of goal; the
  5919 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5920 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5921 for example;
  5922 
  5923 
  5924 
  5925 New in Isabelle98 (January 1998)
  5926 --------------------------------
  5927 
  5928 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5929 
  5930 * changed lexical syntax of terms / types: dots made part of long
  5931 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5932 
  5933 * simpset (and claset) reference variable replaced by functions
  5934 simpset / simpset_ref;
  5935 
  5936 * no longer supports theory aliases (via merge) and non-trivial
  5937 implicit merge of thms' signatures;
  5938 
  5939 * most internal names of constants changed due to qualified names;
  5940 
  5941 * changed Pure/Sequence interface (see Pure/seq.ML);
  5942 
  5943 
  5944 *** General Changes ***
  5945 
  5946 * hierachically structured name spaces (for consts, types, axms, thms
  5947 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5948 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5949 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5950 long_names for fully qualified output names; NOTE: ML programs
  5951 (special tactics, packages etc.) referring to internal names may have
  5952 to be adapted to cope with fully qualified names; in case of severe
  5953 backward campatibility problems try setting 'global_names' at compile
  5954 time to have enrything declared within a flat name space; one may also
  5955 fine tune name declarations in theories via the 'global' and 'local'
  5956 section;
  5957 
  5958 * reimplemented the implicit simpset and claset using the new anytype
  5959 data filed in signatures; references simpset:simpset ref etc. are
  5960 replaced by functions simpset:unit->simpset and
  5961 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5962 to patch your ML files accordingly;
  5963 
  5964 * HTML output now includes theory graph data for display with Java
  5965 applet or isatool browser; data generated automatically via isatool
  5966 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5967 
  5968 * defs may now be conditional; improved rewrite_goals_tac to handle
  5969 conditional equations;
  5970 
  5971 * defs now admits additional type arguments, using TYPE('a) syntax;
  5972 
  5973 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5974 creates a new theory node; implicit merge of thms' signatures is
  5975 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5976 transfer:theory->thm->thm in (rare) cases;
  5977 
  5978 * improved handling of draft signatures / theories; draft thms (and
  5979 ctyps, cterms) are automatically promoted to real ones;
  5980 
  5981 * slightly changed interfaces for oracles: admit many per theory, named
  5982 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5983 
  5984 * print_goals: optional output of const types (set show_consts and
  5985 show_types);
  5986 
  5987 * improved output of warnings (###) and errors (***);
  5988 
  5989 * subgoal_tac displays a warning if the new subgoal has type variables;
  5990 
  5991 * removed old README and Makefiles;
  5992 
  5993 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5994 
  5995 * removed obsolete init_pps and init_database;
  5996 
  5997 * deleted the obsolete tactical STATE, which was declared by
  5998     fun STATE tacfun st = tacfun st st;
  5999 
  6000 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6001 (which abbreviates $HOME);
  6002 
  6003 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6004 use isatool fixseq to adapt your ML programs (this works for fully
  6005 qualified references to the Sequence structure only!);
  6006 
  6007 * use_thy no longer requires writable current directory; it always
  6008 reloads .ML *and* .thy file, if either one is out of date;
  6009 
  6010 
  6011 *** Classical Reasoner ***
  6012 
  6013 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6014 tactics that use classical reasoning to simplify a subgoal without
  6015 splitting it into several subgoals;
  6016 
  6017 * Safe_tac: like safe_tac but uses the default claset;
  6018 
  6019 
  6020 *** Simplifier ***
  6021 
  6022 * added simplification meta rules:
  6023     (asm_)(full_)simplify: simpset -> thm -> thm;
  6024 
  6025 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6026 logics (again);
  6027 
  6028 * added prems argument to simplification procedures;
  6029 
  6030 * HOL, FOL, ZF: added infix function `addsplits':
  6031   instead of `<simpset> setloop (split_tac <thms>)'
  6032   you can simply write `<simpset> addsplits <thms>'
  6033 
  6034 
  6035 *** Syntax ***
  6036 
  6037 * TYPE('a) syntax for type reflection terms;
  6038 
  6039 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6040 
  6041 * pretty printer: changed order of mixfix annotation preference (again!);
  6042 
  6043 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6044 
  6045 
  6046 *** HOL ***
  6047 
  6048 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6049   with `addloop' of the simplifier to faciliate case splitting in premises.
  6050 
  6051 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6052 
  6053 * HOL/Auth: new protocol proofs including some for the Internet
  6054   protocol TLS;
  6055 
  6056 * HOL/Map: new theory of `maps' a la VDM;
  6057 
  6058 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6059 cancelling out common nat summands from =, <, <= (in)equalities, or
  6060 differences; simplification procedures nat_cancel_factor for
  6061 cancelling common factor from =, <, <= (in)equalities over natural
  6062 sums; nat_cancel contains both kinds of procedures, it is installed by
  6063 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6064 
  6065 * HOL/simplifier: terms of the form
  6066   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6067   are rewritten to
  6068   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6069   and those of the form
  6070   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6071   are rewritten to
  6072   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6073 
  6074 * HOL/datatype
  6075   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6076 
  6077   P(t_case f1 ... fn x) =
  6078      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6079         ...
  6080        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6081      )
  6082 
  6083   and a theorem `split_t_case_asm' of the form
  6084 
  6085   P(t_case f1 ... fn x) =
  6086     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6087         ...
  6088        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6089      )
  6090   which can be added to a simpset via `addsplits'. The existing theorems
  6091   expand_list_case and expand_option_case have been renamed to
  6092   split_list_case and split_option_case.
  6093 
  6094 * HOL/Arithmetic:
  6095   - `pred n' is automatically converted to `n-1'.
  6096     Users are strongly encouraged not to use `pred' any longer,
  6097     because it will disappear altogether at some point.
  6098   - Users are strongly encouraged to write "0 < n" rather than
  6099     "n ~= 0". Theorems and proof tools have been modified towards this
  6100     `standard'.
  6101 
  6102 * HOL/Lists:
  6103   the function "set_of_list" has been renamed "set" (and its theorems too);
  6104   the function "nth" now takes its arguments in the reverse order and
  6105   has acquired the infix notation "!" as in "xs!n".
  6106 
  6107 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6108 
  6109 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6110   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6111 
  6112 * HOL/record: extensible records with schematic structural subtyping
  6113 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6114 still lacks various theorems and concrete record syntax;
  6115 
  6116 
  6117 *** HOLCF ***
  6118 
  6119 * removed "axioms" and "generated by" sections;
  6120 
  6121 * replaced "ops" section by extended "consts" section, which is capable of
  6122   handling the continuous function space "->" directly;
  6123 
  6124 * domain package:
  6125   . proves theorems immediately and stores them in the theory,
  6126   . creates hierachical name space,
  6127   . now uses normal mixfix annotations (instead of cinfix...),
  6128   . minor changes to some names and values (for consistency),
  6129   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6130   . separator between mutual domain defs: changed "," to "and",
  6131   . improved handling of sort constraints;  now they have to
  6132     appear on the left-hand side of the equations only;
  6133 
  6134 * fixed LAM <x,y,zs>.b syntax;
  6135 
  6136 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6137 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6138 
  6139 
  6140 *** FOL and ZF ***
  6141 
  6142 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6143   with `addloop' of the simplifier to faciliate case splitting in premises.
  6144 
  6145 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6146 in HOL, they strip ALL and --> from proved theorems;
  6147 
  6148 
  6149 
  6150 New in Isabelle94-8 (May 1997)
  6151 ------------------------------
  6152 
  6153 *** General Changes ***
  6154 
  6155 * new utilities to build / run / maintain Isabelle etc. (in parts
  6156 still somewhat experimental); old Makefiles etc. still functional;
  6157 
  6158 * new 'Isabelle System Manual';
  6159 
  6160 * INSTALL text, together with ./configure and ./build scripts;
  6161 
  6162 * reimplemented type inference for greater efficiency, better error
  6163 messages and clean internal interface;
  6164 
  6165 * prlim command for dealing with lots of subgoals (an easier way of
  6166 setting goals_limit);
  6167 
  6168 
  6169 *** Syntax ***
  6170 
  6171 * supports alternative (named) syntax tables (parser and pretty
  6172 printer); internal interface is provided by add_modesyntax(_i);
  6173 
  6174 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6175 be used in conjunction with the Isabelle symbol font; uses the
  6176 "symbols" syntax table;
  6177 
  6178 * added token_translation interface (may translate name tokens in
  6179 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6180 the current print_mode); IMPORTANT: user print translation functions
  6181 are responsible for marking newly introduced bounds
  6182 (Syntax.mark_boundT);
  6183 
  6184 * token translations for modes "xterm" and "xterm_color" that display
  6185 names in bold, underline etc. or colors (which requires a color
  6186 version of xterm);
  6187 
  6188 * infixes may now be declared with names independent of their syntax;
  6189 
  6190 * added typed_print_translation (like print_translation, but may
  6191 access type of constant);
  6192 
  6193 
  6194 *** Classical Reasoner ***
  6195 
  6196 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6197 some limitations.  Blast_tac...
  6198   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6199   + ignores elimination rules that don't have the correct format
  6200         (the conclusion MUST be a formula variable)
  6201   + ignores types, which can make HOL proofs fail
  6202   + rules must not require higher-order unification, e.g. apply_type in ZF
  6203     [message "Function Var's argument not a bound variable" relates to this]
  6204   + its proof strategy is more general but can actually be slower
  6205 
  6206 * substitution with equality assumptions no longer permutes other
  6207 assumptions;
  6208 
  6209 * minor changes in semantics of addafter (now called addaltern); renamed
  6210 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6211 (and access functions for it);
  6212 
  6213 * improved combination of classical reasoner and simplifier:
  6214   + functions for handling clasimpsets
  6215   + improvement of addss: now the simplifier is called _after_ the
  6216     safe steps.
  6217   + safe variant of addss called addSss: uses safe simplifications
  6218     _during_ the safe steps. It is more complete as it allows multiple
  6219     instantiations of unknowns (e.g. with slow_tac).
  6220 
  6221 *** Simplifier ***
  6222 
  6223 * added interface for simplification procedures (functions that
  6224 produce *proven* rewrite rules on the fly, depending on current
  6225 redex);
  6226 
  6227 * ordering on terms as parameter (used for ordered rewriting);
  6228 
  6229 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6230 
  6231 * the solver is now split into a safe and an unsafe part.
  6232 This should be invisible for the normal user, except that the
  6233 functions setsolver and addsolver have been renamed to setSolver and
  6234 addSolver; added safe_asm_full_simp_tac;
  6235 
  6236 
  6237 *** HOL ***
  6238 
  6239 * a generic induction tactic `induct_tac' which works for all datatypes and
  6240 also for type `nat';
  6241 
  6242 * a generic case distinction tactic `exhaust_tac' which works for all
  6243 datatypes and also for type `nat';
  6244 
  6245 * each datatype comes with a function `size';
  6246 
  6247 * patterns in case expressions allow tuple patterns as arguments to
  6248 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6249 
  6250 * primrec now also works with type nat;
  6251 
  6252 * recdef: a new declaration form, allows general recursive functions to be
  6253 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6254 
  6255 * the constant for negation has been renamed from "not" to "Not" to
  6256 harmonize with FOL, ZF, LK, etc.;
  6257 
  6258 * HOL/ex/LFilter theory of a corecursive "filter" functional for
<