NEWS
author nipkow
Wed Jul 29 12:12:01 2009 +0200 (2009-07-29)
changeset 32270 615c524bd9e4
parent 32264 0be31453f698
child 32326 9d70ecf11b7a
permissions -rw-r--r--
sos documentation
     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 * New proof method "sos" (sum of squares) for nonlinear real arithmetic
    22 (originally due to John Harison). It requires Library/Sum_Of_Squares.
    23 It is not a complete decision procedure but works well in practice
    24 on quantifier-free real arithmetic with +, -, *, ^, =, <= and <,
    25 i.e. boolean combinations of equalities and inequalities between
    26 polynomials. It makes use of external semidefinite programming solvers.
    27 For more information and examples see Library/Sum_Of_Squares.
    28 
    29 * Set.UNIV and Set.empty are mere abbreviations for top and bot.  INCOMPATIBILITY.
    30 
    31 * More convenient names for set intersection and union.  INCOMPATIBILITY:
    32 
    33     Set.Int ~>  Set.inter
    34     Set.Un ~>   Set.union
    35 
    36 * Code generator attributes follow the usual underscore convention:
    37     code_unfold     replaces    code unfold
    38     code_post       replaces    code post
    39     etc.
    40   INCOMPATIBILITY.
    41 
    42 * New quickcheck implementation using new code generator.
    43 
    44 * New class "boolean_algebra".
    45 
    46 * Refinements to lattices classes:
    47   - added boolean_algebra type class
    48   - less default intro/elim rules in locale variant, more default
    49     intro/elim rules in class variant: more uniformity
    50   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    51   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    52   - renamed ACI to inf_sup_aci
    53   - class "complete_lattice" moved to separate theory "complete_lattice";
    54     corresponding constants renamed:
    55     
    56     Set.Inf ~>      Complete_Lattice.Inf
    57     Set.Sup ~>      Complete_Lattice.Sup
    58     Set.INFI ~>     Complete_Lattice.INFI
    59     Set.SUPR ~>     Complete_Lattice.SUPR
    60     Set.Inter ~>    Complete_Lattice.Inter
    61     Set.Union ~>    Complete_Lattice.Union
    62     Set.INTER ~>    Complete_Lattice.INTER
    63     Set.UNION ~>    Complete_Lattice.UNION
    64 
    65   INCOMPATIBILITY.
    66 
    67 * Class semiring_div requires superclass no_zero_divisors and proof of
    68 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    69 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    70 generalized to class semiring_div, subsuming former theorems
    71 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    72 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    73 INCOMPATIBILITY.
    74 
    75 * Power operations on relations and functions are now one dedicate
    76 constant compow with infix syntax "^^".  Power operations on
    77 multiplicative monoids retains syntax "^" and is now defined generic
    78 in class power.  INCOMPATIBILITY.
    79 
    80 * Relation composition "R O S" now has a "more standard" argument order,
    81 i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
    82 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
    83 may occationally break, since the O_assoc rule was not rewritten like this.
    84 Fix using O_assoc[symmetric].
    85 The same applies to the curried version "R OO S".
    86 
    87 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    88 infinite sets. It is shown that they form a complete lattice.
    89 
    90 * ML antiquotation @{code_datatype} inserts definition of a datatype
    91 generated by the code generator; see Predicate.thy for an example.
    92 
    93 * New method "linarith" invokes existing linear arithmetic decision
    94 procedure only.
    95 
    96 * Implementation of quickcheck using generic code generator; default
    97 generators are provided for all suitable HOL types, records and
    98 datatypes.
    99 
   100 * Constants Set.Pow and Set.image now with authentic syntax;
   101 object-logic definitions Set.Pow_def and Set.image_def.
   102 INCOMPATIBILITY.
   103 
   104 * Renamed theorems:
   105 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   106 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   107 Suc_plus1 -> Suc_eq_plus1
   108 
   109 * New sledgehammer option "Full Types" in Proof General settings menu.
   110 Causes full type information to be output to the ATPs.  This slows
   111 ATPs down considerably but eliminates a source of unsound "proofs"
   112 that fail later.
   113 
   114 * Discontinued ancient tradition to suffix certain ML module names
   115 with "_package", e.g.:
   116 
   117     DatatypePackage ~> Datatype
   118     InductivePackage ~> Inductive
   119 
   120     etc.
   121 
   122 INCOMPATIBILITY.
   123 
   124 * NewNumberTheory: Jeremy Avigad's new version of part of
   125 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
   126 
   127 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
   128 
   129 * Abbreviation "arbitrary" of "undefined" has disappeared; use
   130 "undefined" directly.  INCOMPATIBILITY.
   131 
   132 * New evaluator "approximate" approximates an real valued term using
   133 the same method as the approximation method.
   134 
   135 * Method "approximate" supports now arithmetic expressions as
   136 boundaries of intervals and implements interval splitting and Taylor
   137 series expansion.
   138 
   139 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   140 the theorems in DERIV_intros assumes composition with an additional
   141 function and matches a variable to the derivative, which has to be
   142 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   143 the derivative of most elementary terms.
   144 
   145 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   146 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   147 
   148 
   149 *** ML ***
   150 
   151 * Tactical FOCUS is similar to SUBPROOF, but allows the body tactic to
   152 introduce new subgoals and schematic variables.  FOCUS_PARAMS is
   153 similar, but focuses on the parameter prefix only, leaving subgoal
   154 premises unchanged.
   155 
   156 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   157 functors have their own ML name space there is no point to mark them
   158 separately.)  Minor INCOMPATIBILITY.
   159 
   160 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   161 
   162 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   163 cominators for "args".  INCOMPATIBILITY, need to use simplified
   164 Attrib/Method.setup introduced in Isabelle2009.
   165 
   166 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   167 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   168 last resort.  INCOMPATIBILITY.
   169 
   170 * Display.pretty_thm now requires a proper context (cf. former
   171 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   172 or even Display.pretty_thm_without_context as last resort.
   173 INCOMPATIBILITY.
   174 
   175 
   176 *** System ***
   177 
   178 * Discontinued support for Poly/ML 4.x versions.
   179 
   180 * Removed "compress" option from isabelle-process and isabelle usedir;
   181 this is always enabled.
   182 
   183 * More fine-grained control of proof parallelism, cf.
   184 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   185 
   186 
   187 
   188 New in Isabelle2009 (April 2009)
   189 --------------------------------
   190 
   191 *** General ***
   192 
   193 * Simplified main Isabelle executables, with less surprises on
   194 case-insensitive file-systems (such as Mac OS).
   195 
   196   - The main Isabelle tool wrapper is now called "isabelle" instead of
   197     "isatool."
   198 
   199   - The former "isabelle" alias for "isabelle-process" has been
   200     removed (should rarely occur to regular users).
   201 
   202   - The former "isabelle-interface" and its alias "Isabelle" have been
   203     removed (interfaces are now regular Isabelle tools).
   204 
   205 Within scripts and make files, the Isabelle environment variables
   206 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   207 respectively.  (The latter are still available as legacy feature.)
   208 
   209 The old isabelle-interface wrapper could react in confusing ways if
   210 the interface was uninstalled or changed otherwise.  Individual
   211 interface tool configuration is now more explicit, see also the
   212 Isabelle system manual.  In particular, Proof General is now available
   213 via "isabelle emacs".
   214 
   215 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   216 purge installed copies of Isabelle executables and re-run "isabelle
   217 install -p ...", or use symlinks.
   218 
   219 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   220 old ~/isabelle, which was slightly non-standard and apt to cause
   221 surprises on case-insensitive file-systems (such as Mac OS).
   222 
   223 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   224 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   225 care is required when using older releases of Isabelle.  Note that
   226 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   227 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   228 
   229 * Proofs of fully specified statements are run in parallel on
   230 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   231 a regular 4-core machine, if the initial heap space is made reasonably
   232 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   233 
   234 * The main reference manuals ("isar-ref", "implementation", and
   235 "system") have been updated and extended.  Formally checked references
   236 as hyperlinks are now available uniformly.
   237 
   238 
   239 *** Pure ***
   240 
   241 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   242 respects.  The most important changes are listed below.  See the
   243 Tutorial on Locales ("locales" manual) for details.
   244 
   245 - In locale expressions, instantiation replaces renaming.  Parameters
   246 must be declared in a for clause.  To aid compatibility with previous
   247 parameter inheritance, in locale declarations, parameters that are not
   248 'touched' (instantiation position "_" or omitted) are implicitly added
   249 with their syntax at the beginning of the for clause.
   250 
   251 - Syntax from abbreviations and definitions in locales is available in
   252 locale expressions and context elements.  The latter is particularly
   253 useful in locale declarations.
   254 
   255 - More flexible mechanisms to qualify names generated by locale
   256 expressions.  Qualifiers (prefixes) may be specified in locale
   257 expressions, and can be marked as mandatory (syntax: "name!:") or
   258 optional (syntax "name?:").  The default depends for plain "name:"
   259 depends on the situation where a locale expression is used: in
   260 commands 'locale' and 'sublocale' prefixes are optional, in
   261 'interpretation' and 'interpret' prefixes are mandatory.  The old
   262 implicit qualifiers derived from the parameter names of a locale are
   263 no longer generated.
   264 
   265 - Command "sublocale l < e" replaces "interpretation l < e".  The
   266 instantiation clause in "interpretation" and "interpret" (square
   267 brackets) is no longer available.  Use locale expressions.
   268 
   269 - When converting proof scripts, mandatory qualifiers in
   270 'interpretation' and 'interpret' should be retained by default, even
   271 if this is an INCOMPATIBILITY compared to former behavior.  In the
   272 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   273 in locale expressions range over a single locale instance only.
   274 
   275 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   276 In existing theorem specifications replace the includes element by the
   277 respective context elements of the included locale, omitting those
   278 that are already present in the theorem specification.  Multiple
   279 assume elements of a locale should be replaced by a single one
   280 involving the locale predicate.  In the proof body, declarations (most
   281 notably theorems) may be regained by interpreting the respective
   282 locales in the proof context as required (command "interpret").
   283 
   284 If using "includes" in replacement of a target solely because the
   285 parameter types in the theorem are not as general as in the target,
   286 consider declaring a new locale with additional type constraints on
   287 the parameters (context element "constrains").
   288 
   289 - Discontinued "locale (open)".  INCOMPATIBILITY.
   290 
   291 - Locale interpretation commands no longer attempt to simplify goal.
   292 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   293 methods intro_locales and unfold_locales to clarify.
   294 
   295 - Locale interpretation commands no longer accept interpretation
   296 attributes.  INCOMPATIBILITY.
   297 
   298 * Class declaration: so-called "base sort" must not be given in import
   299 list any longer, but is inferred from the specification.  Particularly
   300 in HOL, write
   301 
   302     class foo = ...
   303 
   304 instead of
   305 
   306     class foo = type + ...
   307 
   308 * Class target: global versions of theorems stemming do not carry a
   309 parameter prefix any longer.  INCOMPATIBILITY.
   310 
   311 * Class 'instance' command no longer accepts attached definitions.
   312 INCOMPATIBILITY, use proper 'instantiation' target instead.
   313 
   314 * Recovered hiding of consts, which was accidentally broken in
   315 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   316 makes c inaccessible; consider using ``hide (open) const c'' instead.
   317 
   318 * Slightly more coherent Pure syntax, with updated documentation in
   319 isar-ref manual.  Removed locales meta_term_syntax and
   320 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   321 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   322 directly in regular applications.
   323 
   324 * There is a new syntactic category "float_const" for signed decimal
   325 fractions (e.g. 123.45 or -123.45).
   326 
   327 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   328 interface with 'setup' command instead.
   329 
   330 * Command 'local_setup' is similar to 'setup', but operates on a local
   331 theory context.
   332 
   333 * The 'axiomatization' command now only works within a global theory
   334 context.  INCOMPATIBILITY.
   335 
   336 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   337 hypotheses.  Sorts required in the course of reasoning need to be
   338 covered by the constraints in the initial statement, completed by the
   339 type instance information of the background theory.  Non-trivial sort
   340 hypotheses, which rarely occur in practice, may be specified via
   341 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   342 
   343   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   344 
   345 The result contains an implicit sort hypotheses as before --
   346 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   347 normalization.
   348 
   349 * Generalized Isar history, with support for linear undo, direct state
   350 addressing etc.
   351 
   352 * Changed defaults for unify configuration options:
   353 
   354   unify_trace_bound = 50 (formerly 25)
   355   unify_search_bound = 60 (formerly 30)
   356 
   357 * Different bookkeeping for code equations (INCOMPATIBILITY):
   358 
   359   a) On theory merge, the last set of code equations for a particular
   360      constant is taken (in accordance with the policy applied by other
   361      parts of the code generator framework).
   362 
   363   b) Code equations stemming from explicit declarations (e.g. code
   364      attribute) gain priority over default code equations stemming
   365      from definition, primrec, fun etc.
   366 
   367 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   368 
   369 * Unified theorem tables for both code generators.  Thus [code
   370 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   371 
   372 * Command 'find_consts' searches for constants based on type and name
   373 patterns, e.g.
   374 
   375     find_consts "_ => bool"
   376 
   377 By default, matching is against subtypes, but it may be restricted to
   378 the whole type.  Searching by name is possible.  Multiple queries are
   379 conjunctive and queries may be negated by prefixing them with a
   380 hyphen:
   381 
   382     find_consts strict: "_ => bool" name: "Int" -"int => int"
   383 
   384 * New 'find_theorems' criterion "solves" matches theorems that
   385 directly solve the current goal (modulo higher-order unification).
   386 
   387 * Auto solve feature for main theorem statements: whenever a new goal
   388 is stated, "find_theorems solves" is called; any theorems that could
   389 solve the lemma directly are listed as part of the goal state.
   390 Cf. associated options in Proof General Isabelle settings menu,
   391 enabled by default, with reasonable timeout for pathological cases of
   392 higher-order unification.
   393 
   394 
   395 *** Document preparation ***
   396 
   397 * Antiquotation @{lemma} now imitates a regular terminal proof,
   398 demanding keyword 'by' and supporting the full method expression
   399 syntax just like the Isar command 'by'.
   400 
   401 
   402 *** HOL ***
   403 
   404 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   405 points Main and Complex_Main remain as before.
   406 
   407 * Logic image HOL-Plain provides a minimal HOL with the most important
   408 tools available (inductive, datatype, primrec, ...).  This facilitates
   409 experimentation and tool development.  Note that user applications
   410 (and library theories) should never refer to anything below theory
   411 Main, as before.
   412 
   413 * Logic image HOL-Main stops at theory Main, and thus facilitates
   414 experimentation due to shorter build times.
   415 
   416 * Logic image HOL-NSA contains theories of nonstandard analysis which
   417 were previously part of former HOL-Complex.  Entry point Hyperreal
   418 remains valid, but theories formerly using Complex_Main should now use
   419 new entry point Hypercomplex.
   420 
   421 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   422 Posix processes.  Avoids potentially expensive forking of the ML
   423 process.  New thread-based implementation also works on non-Unix
   424 platforms (Cygwin).  Provers are no longer hardwired, but defined
   425 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   426 commands are covered in the isar-ref manual.
   427 
   428 * Wrapper scripts for remote SystemOnTPTP service allows to use
   429 sledgehammer without local ATP installation (Vampire etc.). Other
   430 provers may be included via suitable ML wrappers, see also
   431 src/HOL/ATP_Linkup.thy.
   432 
   433 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   434 menu.
   435 
   436 * The metis method no longer fails because the theorem is too trivial
   437 (contains the empty clause).
   438 
   439 * The metis method now fails in the usual manner, rather than raising
   440 an exception, if it determines that it cannot prove the theorem.
   441 
   442 * Method "coherent" implements a prover for coherent logic (see also
   443 src/Tools/coherent.ML).
   444 
   445 * Constants "undefined" and "default" replace "arbitrary".  Usually
   446 "undefined" is the right choice to replace "arbitrary", though
   447 logically there is no difference.  INCOMPATIBILITY.
   448 
   449 * Command "value" now integrates different evaluation mechanisms.  The
   450 result of the first successful evaluation mechanism is printed.  In
   451 square brackets a particular named evaluation mechanisms may be
   452 specified (currently, [SML], [code] or [nbe]).  See further
   453 src/HOL/ex/Eval_Examples.thy.
   454 
   455 * Normalization by evaluation now allows non-leftlinear equations.
   456 Declare with attribute [code nbe].
   457 
   458 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   459 as the structured Isar versions "cases" and "induct", cf. the
   460 corresponding "cases" and "induct" attributes.  Mutual induction rules
   461 are now presented as a list of individual projections
   462 (e.g. foo_bar.inducts for types foo and bar); the old format with
   463 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   464 rare situations a different rule is selected --- notably nested tuple
   465 elimination instead of former prod.exhaust: use explicit (case_tac t
   466 rule: prod.exhaust) here.
   467 
   468 * Attributes "cases", "induct", "coinduct" support "del" option.
   469 
   470 * Removed fact "case_split_thm", which duplicates "case_split".
   471 
   472 * The option datatype has been moved to a new theory Option.  Renamed
   473 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   474 
   475 * New predicate "strict_mono" classifies strict functions on partial
   476 orders.  With strict functions on linear orders, reasoning about
   477 (in)equalities is facilitated by theorems "strict_mono_eq",
   478 "strict_mono_less_eq" and "strict_mono_less".
   479 
   480 * Some set operations are now proper qualified constants with
   481 authentic syntax.  INCOMPATIBILITY:
   482 
   483     op Int ~>   Set.Int
   484     op Un ~>    Set.Un
   485     INTER ~>    Set.INTER
   486     UNION ~>    Set.UNION
   487     Inter ~>    Set.Inter
   488     Union ~>    Set.Union
   489     {} ~>       Set.empty
   490     UNIV ~>     Set.UNIV
   491 
   492 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   493 theory Set.
   494 
   495 * Auxiliary class "itself" has disappeared -- classes without any
   496 parameter are treated as expected by the 'class' command.
   497 
   498 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   499 
   500 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   501 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   502 
   503 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   504 method "approximation".  It proves formulas on real values by using
   505 interval arithmetic.  In the formulas are also the transcendental
   506 functions sin, cos, tan, atan, ln, exp and the constant pi are
   507 allowed. For examples see
   508 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   509 
   510 * Theory "Reflection" now resides in HOL/Library.
   511 
   512 * Entry point to Word library now simply named "Word".
   513 INCOMPATIBILITY.
   514 
   515 * Made source layout more coherent with logical distribution
   516 structure:
   517 
   518     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   519     src/HOL/Library/Code_Message.thy ~> src/HOL/
   520     src/HOL/Library/GCD.thy ~> src/HOL/
   521     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   522     src/HOL/Library/Parity.thy ~> src/HOL/
   523     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   524     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   525     src/HOL/Real/Lubs.thy ~> src/HOL/
   526     src/HOL/Real/PReal.thy ~> src/HOL/
   527     src/HOL/Real/Rational.thy ~> src/HOL/
   528     src/HOL/Real/RComplete.thy ~> src/HOL/
   529     src/HOL/Real/RealDef.thy ~> src/HOL/
   530     src/HOL/Real/RealPow.thy ~> src/HOL/
   531     src/HOL/Real/Real.thy ~> src/HOL/
   532     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   533     src/HOL/Complex/Complex.thy ~> src/HOL/
   534     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   535     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   536     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   537     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   538     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   539     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   540     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   541     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   542     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   543     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   544     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   545     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   546     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   547     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   548     src/HOL/Real/Float ~> src/HOL/Library/
   549     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   550     src/HOL/Real/RealVector.thy ~> src/HOL/
   551 
   552     src/HOL/arith_data.ML ~> src/HOL/Tools
   553     src/HOL/hologic.ML ~> src/HOL/Tools
   554     src/HOL/simpdata.ML ~> src/HOL/Tools
   555     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   556     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   557     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   558     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   559     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   560     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   561     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   562 
   563     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   564     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   565     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   566     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   567     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   568     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   569 
   570 * If methods "eval" and "evaluation" encounter a structured proof
   571 state with !!/==>, only the conclusion is evaluated to True (if
   572 possible), avoiding strange error messages.
   573 
   574 * Method "sizechange" automates termination proofs using (a
   575 modification of) the size-change principle.  Requires SAT solver.  See
   576 src/HOL/ex/Termination.thy for examples.
   577 
   578 * Simplifier: simproc for let expressions now unfolds if bound
   579 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   580 
   581 * Method "arith": Linear arithmetic now ignores all inequalities when
   582 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   583 
   584 * New attribute "arith" for facts that should always be used
   585 automatically by arithmetic. It is intended to be used locally in
   586 proofs, e.g.
   587 
   588   assumes [arith]: "x > 0"
   589 
   590 Global usage is discouraged because of possible performance impact.
   591 
   592 * New classes "top" and "bot" with corresponding operations "top" and
   593 "bot" in theory Orderings; instantiation of class "complete_lattice"
   594 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   595 
   596 * Changed definition lemma "less_fun_def" in order to provide an
   597 instance for preorders on functions; use lemma "less_le" instead.
   598 INCOMPATIBILITY.
   599 
   600 * Theory Orderings: class "wellorder" moved here, with explicit
   601 induction rule "less_induct" as assumption.  For instantiation of
   602 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   603 INCOMPATIBILITY.
   604 
   605 * Theory Orderings: added class "preorder" as superclass of "order".
   606 INCOMPATIBILITY: Instantiation proofs for order, linorder
   607 etc. slightly changed.  Some theorems named order_class.* now named
   608 preorder_class.*.
   609 
   610 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   611 "diag" to "Id_on".
   612 
   613 * Theory Finite_Set: added a new fold combinator of type
   614 
   615   ('a => 'b => 'b) => 'b => 'a set => 'b
   616 
   617 Occasionally this is more convenient than the old fold combinator
   618 which is now defined in terms of the new one and renamed to
   619 fold_image.
   620 
   621 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   622 and "ring_simps" have been replaced by "algebra_simps" (which can be
   623 extended with further lemmas!).  At the moment both still exist but
   624 the former will disappear at some point.
   625 
   626 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   627 class recpower.  Type-specific simp rules for various recpower types
   628 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   629 
   630 rat_power_0    -> power_0
   631 rat_power_Suc  -> power_Suc
   632 realpow_0      -> power_0
   633 realpow_Suc    -> power_Suc
   634 complexpow_0   -> power_0
   635 complexpow_Suc -> power_Suc
   636 power_poly_0   -> power_0
   637 power_poly_Suc -> power_Suc
   638 
   639 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   640 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   641 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   642 of lemmas from Divides has been generalized from nat to class
   643 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   644 renames resulting from duplicate elimination:
   645 
   646     dvd_def_mod ~>          dvd_eq_mod_eq_0
   647     zero_dvd_iff ~>         dvd_0_left_iff
   648     dvd_0 ~>                dvd_0_right
   649     DIVISION_BY_ZERO_DIV ~> div_by_0
   650     DIVISION_BY_ZERO_MOD ~> mod_by_0
   651     mult_div ~>             div_mult_self2_is_id
   652     mult_mod ~>             mod_mult_self2_is_0
   653 
   654 * Theory IntDiv: removed many lemmas that are instances of class-based
   655 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   656 rename old lemmas as follows:
   657 
   658 dvd_diff               -> nat_dvd_diff
   659 dvd_zminus_iff         -> dvd_minus_iff
   660 mod_add1_eq            -> mod_add_eq
   661 mod_mult1_eq           -> mod_mult_right_eq
   662 mod_mult1_eq'          -> mod_mult_left_eq
   663 mod_mult_distrib_mod   -> mod_mult_eq
   664 nat_mod_add_left_eq    -> mod_add_left_eq
   665 nat_mod_add_right_eq   -> mod_add_right_eq
   666 nat_mod_div_trivial    -> mod_div_trivial
   667 nat_mod_mod_trivial    -> mod_mod_trivial
   668 zdiv_zadd_self1        -> div_add_self1
   669 zdiv_zadd_self2        -> div_add_self2
   670 zdiv_zmult_self1       -> div_mult_self2_is_id
   671 zdiv_zmult_self2       -> div_mult_self1_is_id
   672 zdvd_triv_left         -> dvd_triv_left
   673 zdvd_triv_right        -> dvd_triv_right
   674 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   675 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   676 zmod_zadd_left_eq      -> mod_add_left_eq
   677 zmod_zadd_right_eq     -> mod_add_right_eq
   678 zmod_zadd_self1        -> mod_add_self1
   679 zmod_zadd_self2        -> mod_add_self2
   680 zmod_zadd1_eq          -> mod_add_eq
   681 zmod_zdiff1_eq         -> mod_diff_eq
   682 zmod_zdvd_zmod         -> mod_mod_cancel
   683 zmod_zmod_cancel       -> mod_mod_cancel
   684 zmod_zmult_self1       -> mod_mult_self2_is_0
   685 zmod_zmult_self2       -> mod_mult_self1_is_0
   686 zmod_1                 -> mod_by_1
   687 zdiv_1                 -> div_by_1
   688 zdvd_abs1              -> abs_dvd_iff
   689 zdvd_abs2              -> dvd_abs_iff
   690 zdvd_refl              -> dvd_refl
   691 zdvd_trans             -> dvd_trans
   692 zdvd_zadd              -> dvd_add
   693 zdvd_zdiff             -> dvd_diff
   694 zdvd_zminus_iff        -> dvd_minus_iff
   695 zdvd_zminus2_iff       -> minus_dvd_iff
   696 zdvd_zmultD            -> dvd_mult_right
   697 zdvd_zmultD2           -> dvd_mult_left
   698 zdvd_zmult_mono        -> mult_dvd_mono
   699 zdvd_0_right           -> dvd_0_right
   700 zdvd_0_left            -> dvd_0_left_iff
   701 zdvd_1_left            -> one_dvd
   702 zminus_dvd_iff         -> minus_dvd_iff
   703 
   704 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   705 
   706 * The real numbers offer decimal input syntax: 12.34 is translated
   707 into 1234/10^2. This translation is not reversed upon output.
   708 
   709 * Theory Library/Polynomial defines an abstract type 'a poly of
   710 univariate polynomials with coefficients of type 'a.  In addition to
   711 the standard ring operations, it also supports div and mod.  Code
   712 generation is also supported, using list-style constructors.
   713 
   714 * Theory Library/Inner_Product defines a class of real_inner for real
   715 inner product spaces, with an overloaded operation inner :: 'a => 'a
   716 => real.  Class real_inner is a subclass of real_normed_vector from
   717 theory RealVector.
   718 
   719 * Theory Library/Product_Vector provides instances for the product
   720 type 'a * 'b of several classes from RealVector and Inner_Product.
   721 Definitions of addition, subtraction, scalar multiplication, norms,
   722 and inner products are included.
   723 
   724 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   725 addition to the field operations, numerals and case syntax are also
   726 supported.
   727 
   728 * Theory Library/Diagonalize provides constructive version of Cantor's
   729 first diagonalization argument.
   730 
   731 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   732 zlcm (for int); carried together from various gcd/lcm developements in
   733 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   734 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   735 may recover tupled syntax as follows:
   736 
   737     hide (open) const gcd
   738     abbreviation gcd where
   739       "gcd == (%(a, b). GCD.gcd a b)"
   740     notation (output)
   741       GCD.gcd ("gcd '(_, _')")
   742 
   743 The same works for lcm, zgcd, zlcm.
   744 
   745 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   746 instantiations for algebraic structures.  Removed some duplicate
   747 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   748 
   749 * ML antiquotation @{code} takes a constant as argument and generates
   750 corresponding code in background and inserts name of the corresponding
   751 resulting ML value/function/datatype constructor binding in place.
   752 All occurrences of @{code} with a single ML block are generated
   753 simultaneously.  Provides a generic and safe interface for
   754 instrumentalizing code generation.  See
   755 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   756 In future you ought to refrain from ad-hoc compiling generated SML
   757 code on the ML toplevel.  Note that (for technical reasons) @{code}
   758 cannot refer to constants for which user-defined serializations are
   759 set.  Refer to the corresponding ML counterpart directly in that
   760 cases.
   761 
   762 * Command 'rep_datatype': instead of theorem names the command now
   763 takes a list of terms denoting the constructors of the type to be
   764 represented as datatype.  The characteristic theorems have to be
   765 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   766 have disappeared in favour of existing ones:
   767 
   768     unit_induct                 ~> unit.induct
   769     prod_induct                 ~> prod.induct
   770     sum_induct                  ~> sum.induct
   771     Suc_Suc_eq                  ~> nat.inject
   772     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   773 
   774 
   775 *** HOL-Algebra ***
   776 
   777 * New locales for orders and lattices where the equivalence relation
   778 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   779 locales use a record structure with field eq for the equivalence.
   780 
   781 * New theory of factorial domains.
   782 
   783 * Units_l_inv and Units_r_inv are now simp rules by default.
   784 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   785 and/or r_inv will now also require deletion of these lemmas.
   786 
   787 * Renamed the following theorems, INCOMPATIBILITY:
   788 
   789 UpperD ~> Upper_memD
   790 LowerD ~> Lower_memD
   791 least_carrier ~> least_closed
   792 greatest_carrier ~> greatest_closed
   793 greatest_Lower_above ~> greatest_Lower_below
   794 one_zero ~> carrier_one_zero
   795 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   796 
   797 
   798 *** HOL-Nominal ***
   799 
   800 * Nominal datatypes can now contain type-variables.
   801 
   802 * Commands 'nominal_inductive' and 'equivariance' work with local
   803 theory targets.
   804 
   805 * Nominal primrec can now works with local theory targets and its
   806 specification syntax now conforms to the general format as seen in
   807 'inductive' etc.
   808 
   809 * Method "perm_simp" honours the standard simplifier attributes
   810 (no_asm), (no_asm_use) etc.
   811 
   812 * The new predicate #* is defined like freshness, except that on the
   813 left hand side can be a set or list of atoms.
   814 
   815 * Experimental command 'nominal_inductive2' derives strong induction
   816 principles for inductive definitions.  In contrast to
   817 'nominal_inductive', which can only deal with a fixed number of
   818 binders, it can deal with arbitrary expressions standing for sets of
   819 atoms to be avoided.  The only inductive definition we have at the
   820 moment that needs this generalisation is the typing rule for Lets in
   821 the algorithm W:
   822 
   823  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   824  -----------------------------------------------------------------
   825          Gamma |- Let x be t1 in t2 : T2
   826 
   827 In this rule one wants to avoid all the binders that are introduced by
   828 "close Gamma T1".  We are looking for other examples where this
   829 feature might be useful.  Please let us know.
   830 
   831 
   832 *** HOLCF ***
   833 
   834 * Reimplemented the simplification procedure for proving continuity
   835 subgoals.  The new simproc is extensible; users can declare additional
   836 continuity introduction rules with the attribute [cont2cont].
   837 
   838 * The continuity simproc now uses a different introduction rule for
   839 solving continuity subgoals on terms with lambda abstractions.  In
   840 some rare cases the new simproc may fail to solve subgoals that the
   841 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   842 Potential INCOMPATIBILITY.
   843 
   844 * Command 'fixrec': specification syntax now conforms to the general
   845 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   846 examples.  INCOMPATIBILITY.
   847 
   848 
   849 *** ZF ***
   850 
   851 * Proof of Zorn's Lemma for partial orders.
   852 
   853 
   854 *** ML ***
   855 
   856 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   857 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   858 depends on multithreading, so timouts will not work before Poly/ML
   859 5.2.1!
   860 
   861 * High-level support for concurrent ML programming, see
   862 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   863 particularly convenient to organize independent functional
   864 computations.  The concept of "synchronized variables" provides a
   865 higher-order interface for components with shared state, avoiding the
   866 delicate details of mutexes and condition variables.  (Requires
   867 Poly/ML 5.2.1 or later.)
   868 
   869 * ML bindings produced via Isar commands are stored within the Isar
   870 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   871 become thread-safe and work with undo as expected (concerning
   872 top-level bindings, not side-effects on global references).
   873 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   874 compiler at runtime; really global bindings need to be given outside a
   875 theory.  (Requires Poly/ML 5.2 or later.)
   876 
   877 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   878 context.  Top-level ML bindings are stored within the proof context in
   879 a purely sequential fashion, disregarding the nested proof structure.
   880 ML bindings introduced by 'ML_prf' are discarded at the end of the
   881 proof.  (Requires Poly/ML 5.2 or later.)
   882 
   883 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   884 and Method.setup, as well as Isar commands 'attribute_setup' and
   885 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   886 existing code accordingly, or use plain 'setup' together with old
   887 Method.add_method.
   888 
   889 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   890 to 'a -> thm, while results are always tagged with an authentic oracle
   891 name.  The Isar command 'oracle' is now polymorphic, no argument type
   892 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   893 accordingly.  Note that extra performance may be gained by producing
   894 the cterm carefully, avoiding slow Thm.cterm_of.
   895 
   896 * Simplified interface for defining document antiquotations via
   897 ThyOutput.antiquotation, ThyOutput.output, and optionally
   898 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   899 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   900 examples.
   901 
   902 * More systematic treatment of long names, abstract name bindings, and
   903 name space operations.  Basic operations on qualified names have been
   904 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   905 Long_Name.append.  Old type bstring has been mostly replaced by
   906 abstract type binding (see structure Binding), which supports precise
   907 qualification by packages and local theory targets, as well as proper
   908 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   909 bstring values into Binding.name, or better pass through abstract
   910 bindings everywhere.  See further src/Pure/General/long_name.ML,
   911 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   912 
   913 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   914 LocalTheory.note etc.) now refer to the *full* internal name, not the
   915 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   916 
   917 * Disposed old type and term read functions (Sign.read_def_typ,
   918 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   919 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   920 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   921 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   922 resort for legacy applications.
   923 
   924 * Disposed old declarations, tactics, tactic combinators that refer to
   925 the simpset or claset of an implicit theory (such as Addsimps,
   926 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   927 embedded ML text, or local_simpset_of with a proper context passed as
   928 explicit runtime argument.
   929 
   930 * Rules and tactics that read instantiations (read_instantiate,
   931 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   932 context, which is required for parsing and type-checking.  Moreover,
   933 the variables are specified as plain indexnames, not string encodings
   934 thereof.  INCOMPATIBILITY.
   935 
   936 * Generic Toplevel.add_hook interface allows to analyze the result of
   937 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   938 for theorem dependency output of transactions resulting in a new
   939 theory state.
   940 
   941 * ML antiquotations: block-structured compilation context indicated by
   942 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   943 
   944   @{binding name}                         - basic name binding
   945   @{let ?pat = term}                      - term abbreviation (HO matching)
   946   @{note name = fact}                     - fact abbreviation
   947   @{thm fact}                             - singleton fact (with attributes)
   948   @{thms fact}                            - general fact (with attributes)
   949   @{lemma prop by method}                 - singleton goal
   950   @{lemma prop by meth1 meth2}            - singleton goal
   951   @{lemma prop1 ... propN by method}      - general goal
   952   @{lemma prop1 ... propN by meth1 meth2} - general goal
   953   @{lemma (open) ...}                     - open derivation
   954 
   955 
   956 *** System ***
   957 
   958 * The Isabelle "emacs" tool provides a specific interface to invoke
   959 Proof General / Emacs, with more explicit failure if that is not
   960 installed (the old isabelle-interface script silently falls back on
   961 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   962 installation location of the Proof General distribution.
   963 
   964 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   965 the Isabelle process into a JVM/Scala application.  See
   966 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   967 process wrapper has been discontinued.)
   968 
   969 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   970 
   971 * Various status messages (with exact source position information) are
   972 emitted, if proper markup print mode is enabled.  This allows
   973 user-interface components to provide detailed feedback on internal
   974 prover operations.
   975 
   976 
   977 
   978 New in Isabelle2008 (June 2008)
   979 -------------------------------
   980 
   981 *** General ***
   982 
   983 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   984 and updated, with formally checked references as hyperlinks.
   985 
   986 * Theory loader: use_thy (and similar operations) no longer set the
   987 implicit ML context, which was occasionally hard to predict and in
   988 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   989 provides a proper context already.
   990 
   991 * Theory loader: old-style ML proof scripts being *attached* to a thy
   992 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   993 'use' within a theory file will do the job.
   994 
   995 * Name space merge now observes canonical order, i.e. the second space
   996 is inserted into the first one, while existing entries in the first
   997 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   998 swap theory imports.
   999 
  1000 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1001 INCOMPATIBILITY in identifier syntax etc.
  1002 
  1003 * Outer syntax: string tokens no longer admit escaped white space,
  1004 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1005 white space without escapes.
  1006 
  1007 * Outer syntax: string tokens may contain arbitrary character codes
  1008 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1009 "foo_bar".
  1010 
  1011 
  1012 *** Pure ***
  1013 
  1014 * Context-dependent token translations.  Default setup reverts locally
  1015 fixed variables, and adds hilite markup for undeclared frees.
  1016 
  1017 * Unused theorems can be found using the new command 'unused_thms'.
  1018 There are three ways of invoking it:
  1019 
  1020 (1) unused_thms
  1021      Only finds unused theorems in the current theory.
  1022 
  1023 (2) unused_thms thy_1 ... thy_n -
  1024      Finds unused theorems in the current theory and all of its ancestors,
  1025      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1026 
  1027 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1028      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1029      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1030      their ancestors.
  1031 
  1032 In order to increase the readability of the list produced by
  1033 unused_thms, theorems that have been created by a particular instance
  1034 of a theory command such as 'inductive' or 'function' are considered
  1035 to belong to the same "group", meaning that if at least one theorem in
  1036 this group is used, the other theorems in the same group are no longer
  1037 reported as unused.  Moreover, if all theorems in the group are
  1038 unused, only one theorem in the group is displayed.
  1039 
  1040 Note that proof objects have to be switched on in order for
  1041 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1042 usually the case when using Proof General with the default settings).
  1043 
  1044 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1045 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1046 duplicate fact bindings, or even accidental fact duplications.  Note
  1047 that tools may maintain dynamically scoped facts systematically, using
  1048 PureThy.add_thms_dynamic.
  1049 
  1050 * Command 'hide' now allows to hide from "fact" name space as well.
  1051 
  1052 * Eliminated destructive theorem database, simpset, claset, and
  1053 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1054 update of theories within ML code.
  1055 
  1056 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1057 INCOMPATIBILITY, object-logics depending on former Pure require
  1058 additional setup PureThy.old_appl_syntax_setup; object-logics
  1059 depending on former CPure need to refer to Pure.
  1060 
  1061 * Commands 'use' and 'ML' are now purely functional, operating on
  1062 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1063 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1064 INCOMPATIBILITY.
  1065 
  1066 * Command 'setup': discontinued implicit version with ML reference.
  1067 
  1068 * Instantiation target allows for simultaneous specification of class
  1069 instance operations together with an instantiation proof.
  1070 Type-checking phase allows to refer to class operations uniformly.
  1071 See src/HOL/Complex/Complex.thy for an Isar example and
  1072 src/HOL/Library/Eval.thy for an ML example.
  1073 
  1074 * Indexing of literal facts: be more serious about including only
  1075 facts from the visible specification/proof context, but not the
  1076 background context (locale etc.).  Affects `prop` notation and method
  1077 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1078 situations.
  1079 
  1080 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1081 "(open)" option, which used to expose internal bound variables to the
  1082 proof text.
  1083 
  1084 * Isar statements: removed obsolete case "rule_context".
  1085 INCOMPATIBILITY, better use explicit fixes/assumes.
  1086 
  1087 * Locale proofs: default proof step now includes 'unfold_locales';
  1088 hence 'proof' without argument may be used to unfold locale
  1089 predicates.
  1090 
  1091 
  1092 *** Document preparation ***
  1093 
  1094 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1095 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1096 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1097 spot); renamed link color from "darkblue" to "linkcolor" (default
  1098 value unchanged, can be redefined via \definecolor); no longer sets
  1099 "a4paper" option (unnecessary or even intrusive).
  1100 
  1101 * Antiquotation @{lemma A method} proves proposition A by the given
  1102 method (either a method name or a method name plus (optional) method
  1103 arguments in parentheses) and prints A just like @{prop A}.
  1104 
  1105 
  1106 *** HOL ***
  1107 
  1108 * New primrec package.  Specification syntax conforms in style to
  1109 definition/function/....  No separate induction rule is provided.  The
  1110 "primrec" command distinguishes old-style and new-style specifications
  1111 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1112 When adjusting theories, beware: constants stemming from new-style
  1113 primrec specifications have authentic syntax.
  1114 
  1115 * Metis prover is now an order of magnitude faster, and also works
  1116 with multithreading.
  1117 
  1118 * Metis: the maximum number of clauses that can be produced from a
  1119 theorem is now given by the attribute max_clauses.  Theorems that
  1120 exceed this number are ignored, with a warning printed.
  1121 
  1122 * Sledgehammer no longer produces structured proofs by default. To
  1123 enable, declare [[sledgehammer_full = true]].  Attributes
  1124 reconstruction_modulus, reconstruction_sorts renamed
  1125 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1126 
  1127 * Method "induct_scheme" derives user-specified induction rules
  1128 from well-founded induction and completeness of patterns. This factors
  1129 out some operations that are done internally by the function package
  1130 and makes them available separately.  See
  1131 src/HOL/ex/Induction_Scheme.thy for examples.
  1132 
  1133 * More flexible generation of measure functions for termination
  1134 proofs: Measure functions can be declared by proving a rule of the
  1135 form "is_measure f" and giving it the [measure_function] attribute.
  1136 The "is_measure" predicate is logically meaningless (always true), and
  1137 just guides the heuristic.  To find suitable measure functions, the
  1138 termination prover sets up the goal "is_measure ?f" of the appropriate
  1139 type and generates all solutions by prolog-style backwards proof using
  1140 the declared rules.
  1141 
  1142 This setup also deals with rules like 
  1143 
  1144   "is_measure f ==> is_measure (list_size f)"
  1145 
  1146 which accommodates nested datatypes that recurse through lists.
  1147 Similar rules are predeclared for products and option types.
  1148 
  1149 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1150 
  1151   INCOMPATIBILITIES:
  1152 
  1153   - Definitions of overloaded constants on sets have to be replaced by
  1154     definitions on => and bool.
  1155 
  1156   - Some definitions of overloaded operators on sets can now be proved
  1157     using the definitions of the operators on => and bool.  Therefore,
  1158     the following theorems have been renamed:
  1159 
  1160       subset_def   -> subset_eq
  1161       psubset_def  -> psubset_eq
  1162       set_diff_def -> set_diff_eq
  1163       Compl_def    -> Compl_eq
  1164       Sup_set_def  -> Sup_set_eq
  1165       Inf_set_def  -> Inf_set_eq
  1166       sup_set_def  -> sup_set_eq
  1167       inf_set_def  -> inf_set_eq
  1168 
  1169   - Due to the incompleteness of the HO unification algorithm, some
  1170     rules such as subst may require manual instantiation, if some of
  1171     the unknowns in the rule is a set.
  1172 
  1173   - Higher order unification and forward proofs:
  1174     The proof pattern
  1175 
  1176       have "P (S::'a set)" <...>
  1177       then have "EX S. P S" ..
  1178 
  1179     no longer works (due to the incompleteness of the HO unification
  1180     algorithm) and must be replaced by the pattern
  1181 
  1182       have "EX S. P S"
  1183       proof
  1184         show "P S" <...>
  1185       qed
  1186 
  1187   - Calculational reasoning with subst (or similar rules):
  1188     The proof pattern
  1189 
  1190       have "P (S::'a set)" <...>
  1191       also have "S = T" <...>
  1192       finally have "P T" .
  1193 
  1194     no longer works (for similar reasons as the previous example) and
  1195     must be replaced by something like
  1196 
  1197       have "P (S::'a set)" <...>
  1198       moreover have "S = T" <...>
  1199       ultimately have "P T" by simp
  1200 
  1201   - Tactics or packages written in ML code:
  1202     Code performing pattern matching on types via
  1203 
  1204       Type ("set", [T]) => ...
  1205 
  1206     must be rewritten. Moreover, functions like strip_type or
  1207     binder_types no longer return the right value when applied to a
  1208     type of the form
  1209 
  1210       T1 => ... => Tn => U => bool
  1211 
  1212     rather than
  1213 
  1214       T1 => ... => Tn => U set
  1215 
  1216 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1217 Wellfounded_Relations to theory Wellfounded.
  1218 
  1219 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1220 
  1221 * Class finite no longer treats UNIV as class parameter.  Use class
  1222 enum from theory Library/Enum instead to achieve a similar effect.
  1223 INCOMPATIBILITY.
  1224 
  1225 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1226 and "Cons".  INCOMPATIBILITY.
  1227 
  1228 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1229 Potential INCOMPATIBILITY.
  1230 
  1231 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1232 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1233 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1234 
  1235 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1236 the same name in theory Orderings:
  1237 
  1238   less_trans
  1239   less_linear
  1240   le_imp_less_or_eq
  1241   le_less_trans
  1242   less_le_trans
  1243   less_not_sym
  1244   less_asym
  1245 
  1246 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1247 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1248 and different variable names.
  1249 
  1250 * Library/Option_ord.thy: Canonical order on option type.
  1251 
  1252 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1253 finite maps.
  1254 
  1255 * Library/Countable.thy: Type class for countable types.
  1256 
  1257 * Theory Int: The representation of numerals has changed.  The infix
  1258 operator BIT and the bit datatype with constructors B0 and B1 have
  1259 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1260 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1261 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1262 accordingly.
  1263 
  1264 * Theory Nat: definition of <= and < on natural numbers no longer
  1265 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1266 le_def and less_def have disappeared.  Consider lemmas not_less
  1267 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1268 
  1269 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1270 (whose purpose mainly is for various fold_set functionals) have been
  1271 abandoned in favor of the existing algebraic classes
  1272 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1273 lower_semilattice (resp. upper_semilattice) and linorder.
  1274 INCOMPATIBILITY.
  1275 
  1276 * Theory Transitive_Closure: induct and cases rules now declare proper
  1277 case_names ("base" and "step").  INCOMPATIBILITY.
  1278 
  1279 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1280 lattices.  The form set-specific version is available as
  1281 Inductive.lfp_ordinal_induct_set.
  1282 
  1283 * Renamed theorems "power.simps" to "power_int.simps".
  1284 INCOMPATIBILITY.
  1285 
  1286 * Class semiring_div provides basic abstract properties of semirings
  1287 with division and modulo operations.  Subsumes former class dvd_mod.
  1288 
  1289 * Merged theories IntDef, Numeral and IntArith into unified theory
  1290 Int.  INCOMPATIBILITY.
  1291 
  1292 * Theory Library/Code_Index: type "index" now represents natural
  1293 numbers rather than integers.  INCOMPATIBILITY.
  1294 
  1295 * New class "uminus" with operation "uminus" (split of from class
  1296 "minus" which now only has operation "minus", binary).
  1297 INCOMPATIBILITY.
  1298 
  1299 * Constants "card", "internal_split", "option_map" now with authentic
  1300 syntax.  INCOMPATIBILITY.
  1301 
  1302 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1303 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1304 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1305 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1306 Sup_set_def, le_def, less_def, option_map_def now with object
  1307 equality.  INCOMPATIBILITY.
  1308 
  1309 * Records. Removed K_record, and replaced it by pure lambda term
  1310 %x. c. The simplifier setup is now more robust against eta expansion.
  1311 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1312 
  1313 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1314 
  1315 * Library/ListVector: new theory of arithmetic vector operations.
  1316 
  1317 * Library/Order_Relation: new theory of various orderings as sets of
  1318 pairs.  Defines preorders, partial orders, linear orders and
  1319 well-orders on sets and on types.
  1320 
  1321 
  1322 *** ZF ***
  1323 
  1324 * Renamed some theories to allow to loading both ZF and HOL in the
  1325 same session:
  1326 
  1327   Datatype  -> Datatype_ZF
  1328   Inductive -> Inductive_ZF
  1329   Int       -> Int_ZF
  1330   IntDiv    -> IntDiv_ZF
  1331   Nat       -> Nat_ZF
  1332   List      -> List_ZF
  1333   Main      -> Main_ZF
  1334 
  1335 INCOMPATIBILITY: ZF theories that import individual theories below
  1336 Main might need to be adapted.  Regular theory Main is still
  1337 available, as trivial extension of Main_ZF.
  1338 
  1339 
  1340 *** ML ***
  1341 
  1342 * ML within Isar: antiquotation @{const name} or @{const
  1343 name(typargs)} produces statically-checked Const term.
  1344 
  1345 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1346 (of the same name).  Removed obsolete print command.
  1347 
  1348 * Removed obsolete "use_legacy_bindings" function.
  1349 
  1350 * The ``print mode'' is now a thread-local value derived from a global
  1351 template (the former print_mode reference), thus access becomes
  1352 non-critical.  The global print_mode reference is for session
  1353 management only; user-code should use print_mode_value,
  1354 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1355 
  1356 * Functions system/system_out provide a robust way to invoke external
  1357 shell commands, with propagation of interrupts (requires Poly/ML
  1358 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1359 
  1360 
  1361 *** System ***
  1362 
  1363 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1364 in accordance with Proof General 3.7, which prefers GNU emacs.
  1365 
  1366 * isatool tty runs Isabelle process with plain tty interaction;
  1367 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1368 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1369 
  1370 * isatool browser now works with Cygwin as well, using general
  1371 "javapath" function defined in Isabelle process environment.
  1372 
  1373 * YXML notation provides a simple and efficient alternative to
  1374 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1375 isatool yxml as described in the Isabelle system manual.
  1376 
  1377 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1378 provides general wrapper for managing an Isabelle process in a robust
  1379 fashion, with ``cooked'' output from stdin/stderr.
  1380 
  1381 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1382 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1383 
  1384 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1385 way of changing the user's settings is via
  1386 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1387 script.
  1388 
  1389 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1390 cores of the underlying machine, which is a good starting point for
  1391 optimal performance tuning.  The corresponding usedir option -M allows
  1392 "max" as an alias for "0".  WARNING: does not work on certain versions
  1393 of Mac OS (with Poly/ML 5.1).
  1394 
  1395 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1396 adverse effect of Isabelle flooding interactive front-ends (notably
  1397 ProofGeneral / XEmacs).
  1398 
  1399 
  1400 
  1401 New in Isabelle2007 (November 2007)
  1402 -----------------------------------
  1403 
  1404 *** General ***
  1405 
  1406 * More uniform information about legacy features, notably a
  1407 warning/error of "Legacy feature: ...", depending on the state of the
  1408 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1409 legacy features will disappear eventually.
  1410 
  1411 * Theory syntax: the header format ``theory A = B + C:'' has been
  1412 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1413 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1414 
  1415 * Theory syntax: the old non-Isar theory file format has been
  1416 discontinued altogether.  Note that ML proof scripts may still be used
  1417 with Isar theories; migration is usually quite simple with the ML
  1418 function use_legacy_bindings.  INCOMPATIBILITY.
  1419 
  1420 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1421 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1422 quotes.
  1423 
  1424 * Theory loader: be more serious about observing the static theory
  1425 header specifications (including optional directories), but not the
  1426 accidental file locations of previously successful loads.  The strict
  1427 update policy of former update_thy is now already performed by
  1428 use_thy, so the former has been removed; use_thys updates several
  1429 theories simultaneously, just as 'imports' within a theory header
  1430 specification, but without merging the results.  Potential
  1431 INCOMPATIBILITY: may need to refine theory headers and commands
  1432 ROOT.ML which depend on load order.
  1433 
  1434 * Theory loader: optional support for content-based file
  1435 identification, instead of the traditional scheme of full physical
  1436 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1437 (cf. the system manual).  The new scheme allows to work with
  1438 non-finished theories in persistent session images, such that source
  1439 files may be moved later on without requiring reloads.
  1440 
  1441 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1442 file (with the same base name as the theory) are considered a legacy
  1443 feature, which will disappear eventually. Even now, the theory loader
  1444 no longer maintains dependencies on such files.
  1445 
  1446 * Syntax: the scope for resolving ambiguities via type-inference is
  1447 now limited to individual terms, instead of whole simultaneous
  1448 specifications as before. This greatly reduces the complexity of the
  1449 syntax module and improves flexibility by separating parsing and
  1450 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1451 'fixes' etc.) are required in rare situations.
  1452 
  1453 * Syntax: constants introduced by new-style packages ('definition',
  1454 'abbreviation' etc.) are passed through the syntax module in
  1455 ``authentic mode''. This means that associated mixfix annotations
  1456 really stick to such constants, independently of potential name space
  1457 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1458 trees are represented slightly differently, may need to adapt syntax
  1459 translations accordingly. Use CONST marker in 'translations' and
  1460 @{const_syntax} antiquotation in 'parse_translation' etc.
  1461 
  1462 * Legacy goal package: reduced interface to the bare minimum required
  1463 to keep existing proof scripts running.  Most other user-level
  1464 functions are now part of the OldGoals structure, which is *not* open
  1465 by default (consider isatool expandshort before open OldGoals).
  1466 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1467 these tend to cause confusion about the actual goal (!) context being
  1468 used here, which is not necessarily the same as the_context().
  1469 
  1470 * Command 'find_theorems': supports "*" wild-card in "name:"
  1471 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1472 support a specific search form (see ProofGeneral/CHANGES).
  1473 
  1474 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1475 by default, which means that "prems" (and also "fixed variables") are
  1476 suppressed from proof state output.  Note that the ProofGeneral
  1477 settings mechanism allows to change and save options persistently, but
  1478 older versions of Isabelle will fail to start up if a negative prems
  1479 limit is imposed.
  1480 
  1481 * Local theory targets may be specified by non-nested blocks of
  1482 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1483 contain definitions, theorems etc., including any derived mechanism
  1484 that has been implemented on top of these primitives.  This concept
  1485 generalizes the existing ``theorem (in ...)'' towards more versatility
  1486 and scalability.
  1487 
  1488 * Proof General interface: proper undo of final 'end' command;
  1489 discontinued Isabelle/classic mode (ML proof scripts).
  1490 
  1491 
  1492 *** Document preparation ***
  1493 
  1494 * Added antiquotation @{theory name} which prints the given name,
  1495 after checking that it refers to a valid ancestor theory in the
  1496 current context.
  1497 
  1498 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1499 check the given source text as ML type/structure, printing verbatim.
  1500 
  1501 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1502 "c args == rhs" given in the current context.  (Any number of
  1503 arguments may be given on the LHS.)
  1504 
  1505 
  1506 *** Pure ***
  1507 
  1508 * The 'class' package offers a combination of axclass and locale to
  1509 achieve Haskell-like type classes in Isabelle.  Definitions and
  1510 theorems within a class context produce both relative results (with
  1511 implicit parameters according to the locale context), and polymorphic
  1512 constants with qualified polymorphism (according to the class
  1513 context).  Within the body context of a 'class' target, a separate
  1514 syntax layer ("user space type system") takes care of converting
  1515 between global polymorphic consts and internal locale representation.
  1516 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1517 "isatool doc classes" provides a tutorial.
  1518 
  1519 * Generic code generator framework allows to generate executable
  1520 code for ML and Haskell (including Isabelle classes).  A short usage
  1521 sketch:
  1522 
  1523     internal compilation:
  1524         export_code <list of constants (term syntax)> in SML
  1525     writing SML code to a file:
  1526         export_code <list of constants (term syntax)> in SML <filename>
  1527     writing OCaml code to a file:
  1528         export_code <list of constants (term syntax)> in OCaml <filename>
  1529     writing Haskell code to a bunch of files:
  1530         export_code <list of constants (term syntax)> in Haskell <filename>
  1531 
  1532     evaluating closed propositions to True/False using code generation:
  1533         method ``eval''
  1534 
  1535 Reasonable default setup of framework in HOL.
  1536 
  1537 Theorem attributs for selecting and transforming function equations theorems:
  1538 
  1539     [code fun]:        select a theorem as function equation for a specific constant
  1540     [code fun del]:    deselect a theorem as function equation for a specific constant
  1541     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1542     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1543 
  1544 User-defined serializations (target in {SML, OCaml, Haskell}):
  1545 
  1546     code_const <and-list of constants (term syntax)>
  1547       {(target) <and-list of const target syntax>}+
  1548 
  1549     code_type <and-list of type constructors>
  1550       {(target) <and-list of type target syntax>}+
  1551 
  1552     code_instance <and-list of instances>
  1553       {(target)}+
  1554         where instance ::= <type constructor> :: <class>
  1555 
  1556     code_class <and_list of classes>
  1557       {(target) <and-list of class target syntax>}+
  1558         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1559 
  1560 code_instance and code_class only are effective to target Haskell.
  1561 
  1562 For example usage see src/HOL/ex/Codegenerator.thy and
  1563 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1564 generation from Isabelle/HOL theories is available via "isatool doc
  1565 codegen".
  1566 
  1567 * Code generator: consts in 'consts_code' Isar commands are now
  1568 referred to by usual term syntax (including optional type
  1569 annotations).
  1570 
  1571 * Command 'no_translations' removes translation rules from theory
  1572 syntax.
  1573 
  1574 * Overloaded definitions are now actually checked for acyclic
  1575 dependencies.  The overloading scheme is slightly more general than
  1576 that of Haskell98, although Isabelle does not demand an exact
  1577 correspondence to type class and instance declarations.
  1578 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1579 exotic versions of overloading -- at the discretion of the user!
  1580 
  1581 Polymorphic constants are represented via type arguments, i.e. the
  1582 instantiation that matches an instance against the most general
  1583 declaration given in the signature.  For example, with the declaration
  1584 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1585 as c(nat).  Overloading is essentially simultaneous structural
  1586 recursion over such type arguments.  Incomplete specification patterns
  1587 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1588 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1589 Command 'print_theory' outputs the normalized system of recursive
  1590 equations, see section "definitions".
  1591 
  1592 * Configuration options are maintained within the theory or proof
  1593 context (with name and type bool/int/string), providing a very simple
  1594 interface to a poor-man's version of general context data.  Tools may
  1595 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1596 these values using Config.get etc.  Users may change options via an
  1597 associated attribute of the same name.  This form of context
  1598 declaration works particularly well with commands 'declare' or
  1599 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1600 very easy to avoid global references, which would not observe Isar
  1601 toplevel undo/redo and fail to work with multithreading.
  1602 
  1603 Various global ML references of Pure and HOL have been turned into
  1604 configuration options:
  1605 
  1606   Unify.search_bound		unify_search_bound
  1607   Unify.trace_bound		unify_trace_bound
  1608   Unify.trace_simp		unify_trace_simp
  1609   Unify.trace_types		unify_trace_types
  1610   Simplifier.simp_depth_limit	simp_depth_limit
  1611   Blast.depth_limit		blast_depth_limit
  1612   DatatypeProp.dtK		datatype_distinctness_limit
  1613   fast_arith_neq_limit  	fast_arith_neq_limit
  1614   fast_arith_split_limit	fast_arith_split_limit
  1615 
  1616 * Named collections of theorems may be easily installed as context
  1617 data using the functor NamedThmsFun (see also
  1618 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1619 attributes; there is also a toplevel print command.  This facility is
  1620 just a common case of general context data, which is the preferred way
  1621 for anything more complex than just a list of facts in canonical
  1622 order.
  1623 
  1624 * Isar: command 'declaration' augments a local theory by generic
  1625 declaration functions written in ML.  This enables arbitrary content
  1626 being added to the context, depending on a morphism that tells the
  1627 difference of the original declaration context wrt. the application
  1628 context encountered later on.
  1629 
  1630 * Isar: proper interfaces for simplification procedures.  Command
  1631 'simproc_setup' declares named simprocs (with match patterns, and body
  1632 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1633 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1634 
  1635 * Isar: an extra pair of brackets around attribute declarations
  1636 abbreviates a theorem reference involving an internal dummy fact,
  1637 which will be ignored later --- only the effect of the attribute on
  1638 the background context will persist.  This form of in-place
  1639 declarations is particularly useful with commands like 'declare' and
  1640 'using', for example ``have A using [[simproc a]] by simp''.
  1641 
  1642 * Isar: method "assumption" (and implicit closing of subproofs) now
  1643 takes simple non-atomic goal assumptions into account: after applying
  1644 an assumption as a rule the resulting subgoals are solved by atomic
  1645 assumption steps.  This is particularly useful to finish 'obtain'
  1646 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1647 without referring to the original premise "!!x. P x ==> thesis" in the
  1648 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1649 more permissive.
  1650 
  1651 * Isar: implicit use of prems from the Isar proof context is
  1652 considered a legacy feature.  Common applications like ``have A .''
  1653 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1654 referencing facts explicitly here improves readability and
  1655 maintainability of proof texts.
  1656 
  1657 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1658 the obtained context from the course of reasoning!  For example:
  1659 
  1660   assume "EX x y. A x & B y"   -- "any previous fact"
  1661   then guess x and y by clarify
  1662 
  1663 This technique is potentially adventurous, depending on the facts and
  1664 proof tools being involved here.
  1665 
  1666 * Isar: known facts from the proof context may be specified as literal
  1667 propositions, using ASCII back-quote syntax.  This works wherever
  1668 named facts used to be allowed so far, in proof commands, proof
  1669 methods, attributes etc.  Literal facts are retrieved from the context
  1670 according to unification of type and term parameters.  For example,
  1671 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1672 theorems in the current context, then these are valid literal facts:
  1673 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1674 
  1675 There is also a proof method "fact" which does the same composition
  1676 for explicit goal states, e.g. the following proof texts coincide with
  1677 certain special cases of literal facts:
  1678 
  1679   have "A" by fact                 ==  note `A`
  1680   have "A ==> B" by fact           ==  note `A ==> B`
  1681   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1682   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1683 
  1684 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1685 outer syntax.  Thus symbolic identifiers may be used without
  1686 additional white space in declarations like this: ``assume *: A''.
  1687 
  1688 * Isar: 'print_facts' prints all local facts of the current context,
  1689 both named and unnamed ones.
  1690 
  1691 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1692 
  1693   def x == "t" and y == "u"
  1694 
  1695 * Isar: added command 'unfolding', which is structurally similar to
  1696 'using', but affects both the goal state and facts by unfolding given
  1697 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1698 'unfolded' attribute may be replaced by first-class proof text.
  1699 
  1700 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1701 and command 'unfolding' now all support object-level equalities
  1702 (potentially conditional).  The underlying notion of rewrite rule is
  1703 analogous to the 'rule_format' attribute, but *not* that of the
  1704 Simplifier (which is usually more generous).
  1705 
  1706 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1707 premises of a theorem by n. Useful in conjunction with drule.
  1708 
  1709 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1710 method expression within a sandbox consisting of the first N
  1711 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1712 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1713 simplifies all new goals that emerge from applying rule foo to the
  1714 originally first one.
  1715 
  1716 * Isar: schematic goals are no longer restricted to higher-order
  1717 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1718 expected.
  1719 
  1720 * Isar: the conclusion of a long theorem statement is now either
  1721 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1722 (essentially a disjunction of cases with local parameters and
  1723 assumptions).  The latter allows to express general elimination rules
  1724 adequately; in this notation common elimination rules look like this:
  1725 
  1726   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1727     assumes "EX x. P x"
  1728     obtains x where "P x"
  1729 
  1730   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1731     assumes "A & B"
  1732     obtains A and B
  1733 
  1734   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1735     assumes "A | B"
  1736     obtains
  1737       A
  1738     | B
  1739 
  1740 The subsequent classical rules even refer to the formal "thesis"
  1741 explicitly:
  1742 
  1743   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1744     obtains "~ thesis"
  1745 
  1746   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1747     obtains "thesis ==> something"
  1748 
  1749 The actual proof of an 'obtains' statement is analogous to that of the
  1750 Isar proof element 'obtain', only that there may be several cases.
  1751 Optional case names may be specified in parentheses; these will be
  1752 available both in the present proof and as annotations in the
  1753 resulting rule, for later use with the 'cases' method (cf. attribute
  1754 case_names).
  1755 
  1756 * Isar: the assumptions of a long theorem statement are available as
  1757 "assms" fact in the proof context.  This is more appropriate than the
  1758 (historical) "prems", which refers to all assumptions of the current
  1759 context, including those from the target locale, proof body etc.
  1760 
  1761 * Isar: 'print_statement' prints theorems from the current theory or
  1762 proof context in long statement form, according to the syntax of a
  1763 top-level lemma.
  1764 
  1765 * Isar: 'obtain' takes an optional case name for the local context
  1766 introduction rule (default "that").
  1767 
  1768 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1769 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1770 to occur.
  1771 
  1772 * Pure: syntax "CONST name" produces a fully internalized constant
  1773 according to the current context.  This is particularly useful for
  1774 syntax translations that should refer to internal constant
  1775 representations independently of name spaces.
  1776 
  1777 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1778 instead of "FOO ". This allows multiple binder declarations to coexist
  1779 in the same context.  INCOMPATIBILITY.
  1780 
  1781 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1782 primitive that also works in a locale context (both for constants and
  1783 fixed variables). Type declaration and internal syntactic representation
  1784 of given constants retrieved from the context. Likewise, the
  1785 'no_notation' command allows to remove given syntax annotations from the
  1786 current context.
  1787 
  1788 * Isar/locales: new derived specification elements 'axiomatization',
  1789 'definition', 'abbreviation', which support type-inference, admit
  1790 object-level specifications (equality, equivalence).  See also the
  1791 isar-ref manual.  Examples:
  1792 
  1793   axiomatization
  1794     eq  (infix "===" 50) where
  1795     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1796 
  1797   definition "f x y = x + y + 1"
  1798   definition g where "g x = f x x"
  1799 
  1800   abbreviation
  1801     neq  (infix "=!=" 50) where
  1802     "x =!= y == ~ (x === y)"
  1803 
  1804 These specifications may be also used in a locale context.  Then the
  1805 constants being introduced depend on certain fixed parameters, and the
  1806 constant name is qualified by the locale base name.  An internal
  1807 abbreviation takes care for convenient input and output, making the
  1808 parameters implicit and using the original short name.  See also
  1809 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1810 entities from a monomorphic theory.
  1811 
  1812 Presently, abbreviations are only available 'in' a target locale, but
  1813 not inherited by general import expressions.  Also note that
  1814 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1815 'translations' in common applications.  The "no_abbrevs" print mode
  1816 prevents folding of abbreviations in term output.
  1817 
  1818 Concrete syntax is attached to specified constants in internal form,
  1819 independently of name spaces.  The parse tree representation is
  1820 slightly different -- use 'notation' instead of raw 'syntax', and
  1821 'translations' with explicit "CONST" markup to accommodate this.
  1822 
  1823 * Pure/Isar: unified syntax for new-style specification mechanisms
  1824 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1825 full type inference and dummy patterns ("_").  For example:
  1826 
  1827   definition "K x _ = x"
  1828 
  1829   inductive conj for A B
  1830   where "A ==> B ==> conj A B"
  1831 
  1832 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1833 the current context.  Print mode "no_abbrevs" prevents inversion of
  1834 abbreviations on output.
  1835 
  1836 * Isar/locales: improved parameter handling: use of locales "var" and
  1837 "struct" no longer necessary; - parameter renamings are no longer
  1838 required to be injective.  For example, this allows to define
  1839 endomorphisms as locale endom = homom mult mult h.
  1840 
  1841 * Isar/locales: changed the way locales with predicates are defined.
  1842 Instead of accumulating the specification, the imported expression is
  1843 now an interpretation.  INCOMPATIBILITY: different normal form of
  1844 locale expressions.  In particular, in interpretations of locales with
  1845 predicates, goals repesenting already interpreted fragments are not
  1846 removed automatically.  Use methods `intro_locales' and
  1847 `unfold_locales'; see below.
  1848 
  1849 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1850 provide backward reasoning on locales predicates.  The methods are
  1851 aware of interpretations and discharge corresponding goals.
  1852 `intro_locales' is less aggressive then `unfold_locales' and does not
  1853 unfold predicates to assumptions.
  1854 
  1855 * Isar/locales: the order in which locale fragments are accumulated
  1856 has changed.  This enables to override declarations from fragments due
  1857 to interpretations -- for example, unwanted simp rules.
  1858 
  1859 * Isar/locales: interpretation in theories and proof contexts has been
  1860 extended.  One may now specify (and prove) equations, which are
  1861 unfolded in interpreted theorems.  This is useful for replacing
  1862 defined concepts (constants depending on locale parameters) by
  1863 concepts already existing in the target context.  Example:
  1864 
  1865   interpretation partial_order ["op <= :: [int, int] => bool"]
  1866     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1867 
  1868 Typically, the constant `partial_order.less' is created by a
  1869 definition specification element in the context of locale
  1870 partial_order.
  1871 
  1872 * Method "induct": improved internal context management to support
  1873 local fixes and defines on-the-fly. Thus explicit meta-level
  1874 connectives !!  and ==> are rarely required anymore in inductive goals
  1875 (using object-logic connectives for this purpose has been long
  1876 obsolete anyway). Common proof patterns are explained in
  1877 src/HOL/Induct/Common_Patterns.thy, see also
  1878 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1879 examples.
  1880 
  1881 * Method "induct": improved handling of simultaneous goals. Instead of
  1882 introducing object-level conjunction, the statement is now split into
  1883 several conclusions, while the corresponding symbolic cases are nested
  1884 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1885 see src/HOL/Induct/Common_Patterns.thy, for example.
  1886 
  1887 * Method "induct": mutual induction rules are now specified as a list
  1888 of rule sharing the same induction cases. HOL packages usually provide
  1889 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1890 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1891 mutual induction rules differently, i.e. like this:
  1892 
  1893   (induct rule: foo_bar.inducts)
  1894   (induct set: foo bar)
  1895   (induct pred: foo bar)
  1896   (induct type: foo bar)
  1897 
  1898 The ML function ProjectRule.projections turns old-style rules into the
  1899 new format.
  1900 
  1901 * Method "coinduct": dual of induction, see
  1902 src/HOL/Library/Coinductive_List.thy for various examples.
  1903 
  1904 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1905 considered a legacy feature.
  1906 
  1907 * Attribute "symmetric" produces result with standardized schematic
  1908 variables (index 0).  Potential INCOMPATIBILITY.
  1909 
  1910 * Simplifier: by default the simplifier trace only shows top level
  1911 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1912 default. Thus there is less danger of being flooded by the trace. The
  1913 trace indicates where parts have been suppressed.
  1914   
  1915 * Provers/classical: removed obsolete classical version of elim_format
  1916 attribute; classical elim/dest rules are now treated uniformly when
  1917 manipulating the claset.
  1918 
  1919 * Provers/classical: stricter checks to ensure that supplied intro,
  1920 dest and elim rules are well-formed; dest and elim rules must have at
  1921 least one premise.
  1922 
  1923 * Provers/classical: attributes dest/elim/intro take an optional
  1924 weight argument for the rule (just as the Pure versions).  Weights are
  1925 ignored by automated tools, but determine the search order of single
  1926 rule steps.
  1927 
  1928 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1929 where the body does not mention the bound variable.  Note that dummy
  1930 patterns implicitly depend on their context of bounds, which makes
  1931 "{_. _}" match any set comprehension as expected.  Potential
  1932 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1933 constant "_idtdummy" in the binding position.
  1934 
  1935 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1936 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1937 for example "A -> B" => "Pi A (%_. B)".
  1938 
  1939 * Pure: 'class_deps' command visualizes the subclass relation, using
  1940 the graph browser tool.
  1941 
  1942 * Pure: 'print_theory' now suppresses certain internal declarations by
  1943 default; use '!' option for full details.
  1944 
  1945 
  1946 *** HOL ***
  1947 
  1948 * Method "metis" proves goals by applying the Metis general-purpose
  1949 resolution prover (see also http://gilith.com/software/metis/).
  1950 Examples are in the directory MetisExamples.  WARNING: the
  1951 Isabelle/HOL-Metis integration does not yet work properly with
  1952 multi-threading.
  1953   
  1954 * Command 'sledgehammer' invokes external automatic theorem provers as
  1955 background processes.  It generates calls to the "metis" method if
  1956 successful. These can be pasted into the proof.  Users do not have to
  1957 wait for the automatic provers to return.  WARNING: does not really
  1958 work with multi-threading.
  1959 
  1960 * New "auto_quickcheck" feature tests outermost goal statements for
  1961 potential counter-examples.  Controlled by ML references
  1962 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1963 5000 milliseconds).  Fails silently if statements is outside of
  1964 executable fragment, or any other codgenerator problem occurs.
  1965 
  1966 * New constant "undefined" with axiom "undefined x = undefined".
  1967 
  1968 * Added class "HOL.eq", allowing for code generation with polymorphic
  1969 equality.
  1970 
  1971 * Some renaming of class constants due to canonical name prefixing in
  1972 the new 'class' package:
  1973 
  1974     HOL.abs ~> HOL.abs_class.abs
  1975     HOL.divide ~> HOL.divide_class.divide
  1976     0 ~> HOL.zero_class.zero
  1977     1 ~> HOL.one_class.one
  1978     op + ~> HOL.plus_class.plus
  1979     op - ~> HOL.minus_class.minus
  1980     uminus ~> HOL.minus_class.uminus
  1981     op * ~> HOL.times_class.times
  1982     op < ~> HOL.ord_class.less
  1983     op <= > HOL.ord_class.less_eq
  1984     Nat.power ~> Power.power_class.power
  1985     Nat.size ~> Nat.size_class.size
  1986     Numeral.number_of ~> Numeral.number_class.number_of
  1987     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1988     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1989     Orderings.min ~> Orderings.ord_class.min
  1990     Orderings.max ~> Orderings.ord_class.max
  1991     Divides.op div ~> Divides.div_class.div
  1992     Divides.op mod ~> Divides.div_class.mod
  1993     Divides.op dvd ~> Divides.div_class.dvd
  1994 
  1995 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1996 
  1997 a) User-defined constants using any of the names "plus", "minus",
  1998 "times", "less" or "less_eq". The standard syntax translations for
  1999 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2000 names.
  2001 
  2002 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2003 INCOMPATIBILITY: use more specific names.
  2004 
  2005 c) Permutative equations (e.g. "a + b = b + a")
  2006 Since the change of names also changes the order of terms, permutative
  2007 rewrite rules may get applied in a different order. Experience shows
  2008 that this is rarely the case (only two adaptions in the whole Isabelle
  2009 distribution).  INCOMPATIBILITY: rewrite proofs
  2010 
  2011 d) ML code directly refering to constant names
  2012 This in general only affects hand-written proof tactics, simprocs and
  2013 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2014 Consider using @{const_name} antiquotation.
  2015 
  2016 * New class "default" with associated constant "default".
  2017 
  2018 * Function "sgn" is now overloaded and available on int, real, complex
  2019 (and other numeric types), using class "sgn".  Two possible defs of
  2020 sgn are given as equational assumptions in the classes sgn_if and
  2021 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2022 INCOMPATIBILITY.
  2023 
  2024 * Locale "partial_order" now unified with class "order" (cf. theory
  2025 Orderings), added parameter "less".  INCOMPATIBILITY.
  2026 
  2027 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2028 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2029 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2030 
  2031 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2032 changed order of proof goals in instance proofs.
  2033 
  2034 * The transitivity reasoner for partial and linear orders is set up
  2035 for classes "order" and "linorder".  Instances of the reasoner are available
  2036 in all contexts importing or interpreting the corresponding locales.
  2037 Method "order" invokes the reasoner separately; the reasoner
  2038 is also integrated with the Simplifier as a solver.  Diagnostic
  2039 command 'print_orders' shows the available instances of the reasoner
  2040 in the current context.
  2041 
  2042 * Localized monotonicity predicate in theory "Orderings"; integrated
  2043 lemmas max_of_mono and min_of_mono with this predicate.
  2044 INCOMPATIBILITY.
  2045 
  2046 * Formulation of theorem "dense" changed slightly due to integration
  2047 with new class dense_linear_order.
  2048 
  2049 * Uniform lattice theory development in HOL.
  2050 
  2051     constants "meet" and "join" now named "inf" and "sup"
  2052     constant "Meet" now named "Inf"
  2053 
  2054     classes "meet_semilorder" and "join_semilorder" now named
  2055       "lower_semilattice" and "upper_semilattice"
  2056     class "lorder" now named "lattice"
  2057     class "comp_lat" now named "complete_lattice"
  2058 
  2059     Instantiation of lattice classes allows explicit definitions
  2060     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2061 
  2062   INCOMPATIBILITY.  Theorem renames:
  2063 
  2064     meet_left_le            ~> inf_le1
  2065     meet_right_le           ~> inf_le2
  2066     join_left_le            ~> sup_ge1
  2067     join_right_le           ~> sup_ge2
  2068     meet_join_le            ~> inf_sup_ord
  2069     le_meetI                ~> le_infI
  2070     join_leI                ~> le_supI
  2071     le_meet                 ~> le_inf_iff
  2072     le_join                 ~> ge_sup_conv
  2073     meet_idempotent         ~> inf_idem
  2074     join_idempotent         ~> sup_idem
  2075     meet_comm               ~> inf_commute
  2076     join_comm               ~> sup_commute
  2077     meet_leI1               ~> le_infI1
  2078     meet_leI2               ~> le_infI2
  2079     le_joinI1               ~> le_supI1
  2080     le_joinI2               ~> le_supI2
  2081     meet_assoc              ~> inf_assoc
  2082     join_assoc              ~> sup_assoc
  2083     meet_left_comm          ~> inf_left_commute
  2084     meet_left_idempotent    ~> inf_left_idem
  2085     join_left_comm          ~> sup_left_commute
  2086     join_left_idempotent    ~> sup_left_idem
  2087     meet_aci                ~> inf_aci
  2088     join_aci                ~> sup_aci
  2089     le_def_meet             ~> le_iff_inf
  2090     le_def_join             ~> le_iff_sup
  2091     join_absorp2            ~> sup_absorb2
  2092     join_absorp1            ~> sup_absorb1
  2093     meet_absorp1            ~> inf_absorb1
  2094     meet_absorp2            ~> inf_absorb2
  2095     meet_join_absorp        ~> inf_sup_absorb
  2096     join_meet_absorp        ~> sup_inf_absorb
  2097     distrib_join_le         ~> distrib_sup_le
  2098     distrib_meet_le         ~> distrib_inf_le
  2099 
  2100     add_meet_distrib_left   ~> add_inf_distrib_left
  2101     add_join_distrib_left   ~> add_sup_distrib_left
  2102     is_join_neg_meet        ~> is_join_neg_inf
  2103     is_meet_neg_join        ~> is_meet_neg_sup
  2104     add_meet_distrib_right  ~> add_inf_distrib_right
  2105     add_join_distrib_right  ~> add_sup_distrib_right
  2106     add_meet_join_distribs  ~> add_sup_inf_distribs
  2107     join_eq_neg_meet        ~> sup_eq_neg_inf
  2108     meet_eq_neg_join        ~> inf_eq_neg_sup
  2109     add_eq_meet_join        ~> add_eq_inf_sup
  2110     meet_0_imp_0            ~> inf_0_imp_0
  2111     join_0_imp_0            ~> sup_0_imp_0
  2112     meet_0_eq_0             ~> inf_0_eq_0
  2113     join_0_eq_0             ~> sup_0_eq_0
  2114     neg_meet_eq_join        ~> neg_inf_eq_sup
  2115     neg_join_eq_meet        ~> neg_sup_eq_inf
  2116     join_eq_if              ~> sup_eq_if
  2117 
  2118     mono_meet               ~> mono_inf
  2119     mono_join               ~> mono_sup
  2120     meet_bool_eq            ~> inf_bool_eq
  2121     join_bool_eq            ~> sup_bool_eq
  2122     meet_fun_eq             ~> inf_fun_eq
  2123     join_fun_eq             ~> sup_fun_eq
  2124     meet_set_eq             ~> inf_set_eq
  2125     join_set_eq             ~> sup_set_eq
  2126     meet1_iff               ~> inf1_iff
  2127     meet2_iff               ~> inf2_iff
  2128     meet1I                  ~> inf1I
  2129     meet2I                  ~> inf2I
  2130     meet1D1                 ~> inf1D1
  2131     meet2D1                 ~> inf2D1
  2132     meet1D2                 ~> inf1D2
  2133     meet2D2                 ~> inf2D2
  2134     meet1E                  ~> inf1E
  2135     meet2E                  ~> inf2E
  2136     join1_iff               ~> sup1_iff
  2137     join2_iff               ~> sup2_iff
  2138     join1I1                 ~> sup1I1
  2139     join2I1                 ~> sup2I1
  2140     join1I1                 ~> sup1I1
  2141     join2I2                 ~> sup1I2
  2142     join1CI                 ~> sup1CI
  2143     join2CI                 ~> sup2CI
  2144     join1E                  ~> sup1E
  2145     join2E                  ~> sup2E
  2146 
  2147     is_meet_Meet            ~> is_meet_Inf
  2148     Meet_bool_def           ~> Inf_bool_def
  2149     Meet_fun_def            ~> Inf_fun_def
  2150     Meet_greatest           ~> Inf_greatest
  2151     Meet_lower              ~> Inf_lower
  2152     Meet_set_def            ~> Inf_set_def
  2153 
  2154     Sup_def                 ~> Sup_Inf
  2155     Sup_bool_eq             ~> Sup_bool_def
  2156     Sup_fun_eq              ~> Sup_fun_def
  2157     Sup_set_eq              ~> Sup_set_def
  2158 
  2159     listsp_meetI            ~> listsp_infI
  2160     listsp_meet_eq          ~> listsp_inf_eq
  2161 
  2162     meet_min                ~> inf_min
  2163     join_max                ~> sup_max
  2164 
  2165 * Added syntactic class "size"; overloaded constant "size" now has
  2166 type "'a::size ==> bool"
  2167 
  2168 * Internal reorganisation of `size' of datatypes: size theorems
  2169 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2170 simplification rules by default!); theorems "prod.size" now named
  2171 "*.size".
  2172 
  2173 * Class "div" now inherits from class "times" rather than "type".
  2174 INCOMPATIBILITY.
  2175 
  2176 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2177 Linorder etc.  have disappeared; operations defined in terms of
  2178 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2179 
  2180 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2181 
  2182 * HOL-Word: New extensive library and type for generic, fixed size
  2183 machine words, with arithemtic, bit-wise, shifting and rotating
  2184 operations, reflection into int, nat, and bool lists, automation for
  2185 linear arithmetic (by automatic reflection into nat or int), including
  2186 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2187 arithmetic type classes, supporting automatic simplification of
  2188 numerals on all operations.
  2189 
  2190 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2191 
  2192 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2193 
  2194 * Code generator library theories:
  2195   - Code_Integer represents HOL integers by big integer literals in target
  2196     languages.
  2197   - Code_Char represents HOL characters by character literals in target
  2198     languages.
  2199   - Code_Char_chr like Code_Char, but also offers treatment of character
  2200     codes; includes Code_Integer.
  2201   - Executable_Set allows to generate code for finite sets using lists.
  2202   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2203     denominator).
  2204   - Executable_Real implements a subset of real numbers, namly those
  2205     representable by rational numbers.
  2206   - Efficient_Nat implements natural numbers by integers, which in general will
  2207     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2208     includes Code_Integer.
  2209   - Code_Index provides an additional datatype index which is mapped to
  2210     target-language built-in integers.
  2211   - Code_Message provides an additional datatype message_string which is isomorphic to
  2212     strings; messages are mapped to target-language strings.
  2213 
  2214 * New package for inductive predicates
  2215 
  2216   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2217 
  2218     inductive
  2219       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2220       for z_1 :: U_1 and ... and z_n :: U_m
  2221     where
  2222       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2223     | ...
  2224 
  2225   with full support for type-inference, rather than
  2226 
  2227     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2228 
  2229     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2230     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2231 
  2232     inductive "s z_1 ... z_m"
  2233     intros
  2234       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2235       ...
  2236 
  2237   For backward compatibility, there is a wrapper allowing inductive
  2238   sets to be defined with the new package via
  2239 
  2240     inductive_set
  2241       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2242       for z_1 :: U_1 and ... and z_n :: U_m
  2243     where
  2244       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2245     | ...
  2246 
  2247   or
  2248 
  2249     inductive_set
  2250       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2251       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2252       for z_1 :: U_1 and ... and z_n :: U_m
  2253     where
  2254       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2255     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2256     | ...
  2257 
  2258   if the additional syntax "p ..." is required.
  2259 
  2260   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2261   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2262 
  2263   INCOMPATIBILITIES:
  2264 
  2265   - Since declaration and definition of inductive sets or predicates
  2266     is no longer separated, abbreviations involving the newly
  2267     introduced sets or predicates must be specified together with the
  2268     introduction rules after the 'where' keyword (see above), rather
  2269     than before the actual inductive definition.
  2270 
  2271   - The variables in induction and elimination rules are now
  2272     quantified in the order of their occurrence in the introduction
  2273     rules, rather than in alphabetical order. Since this may break
  2274     some proofs, these proofs either have to be repaired, e.g. by
  2275     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2276     statements of the form
  2277 
  2278       case (rule_i a_i_1 ... a_i_{k_i})
  2279 
  2280     or the old order of quantification has to be restored by explicitly adding
  2281     meta-level quantifiers in the introduction rules, i.e.
  2282 
  2283       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2284 
  2285   - The format of the elimination rules is now
  2286 
  2287       p z_1 ... z_m x_1 ... x_n ==>
  2288         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2289         ==> ... ==> P
  2290 
  2291     for predicates and
  2292 
  2293       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2294         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2295         ==> ... ==> P
  2296 
  2297     for sets rather than
  2298 
  2299       x : s z_1 ... z_m ==>
  2300         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2301         ==> ... ==> P
  2302 
  2303     This may require terms in goals to be expanded to n-tuples
  2304     (e.g. using case_tac or simplification with the split_paired_all
  2305     rule) before the above elimination rule is applicable.
  2306 
  2307   - The elimination or case analysis rules for (mutually) inductive
  2308     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2309     list of rules "p_1_..._p_k.elims" is no longer available.
  2310 
  2311 * New package "function"/"fun" for general recursive functions,
  2312 supporting mutual and nested recursion, definitions in local contexts,
  2313 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2314 for small examples, and the separate tutorial on the function
  2315 package. The old recdef "package" is still available as before, but
  2316 users are encouraged to use the new package.
  2317 
  2318 * Method "lexicographic_order" automatically synthesizes termination
  2319 relations as lexicographic combinations of size measures. 
  2320 
  2321 * Case-expressions allow arbitrary constructor-patterns (including
  2322 "_") and take their order into account, like in functional
  2323 programming.  Internally, this is translated into nested
  2324 case-expressions; missing cases are added and mapped to the predefined
  2325 constant "undefined". In complicated cases printing may no longer show
  2326 the original input but the internal form. Lambda-abstractions allow
  2327 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2328 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2329 variable.
  2330 
  2331 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2332 is an abbreviation for "of_nat :: nat => int". The simplification
  2333 rules for "of_nat" have been changed to work like "int" did
  2334 previously.  Potential INCOMPATIBILITY:
  2335   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2336   - of_nat_diff and of_nat_mult are no longer default simp rules
  2337 
  2338 * Method "algebra" solves polynomial equations over (semi)rings using
  2339 Groebner bases. The (semi)ring structure is defined by locales and the
  2340 tool setup depends on that generic context. Installing the method for
  2341 a specific type involves instantiating the locale and possibly adding
  2342 declarations for computation on the coefficients.  The method is
  2343 already instantiated for natural numbers and for the axiomatic class
  2344 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2345 CALCULEMUS 2007 for the general principles underlying this
  2346 architecture of context-aware proof-tools.
  2347 
  2348 * Method "ferrack" implements quantifier elimination over
  2349 special-purpose dense linear orders using locales (analogous to
  2350 "algebra"). The method is already installed for class
  2351 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2352 rat, etc.
  2353 
  2354 * Former constant "List.op @" now named "List.append".  Use ML
  2355 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2356 circumvent possible incompatibilities when working on ML level.
  2357 
  2358 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2359 
  2360 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2361 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2362 
  2363 * New syntax for Haskell-like list comprehension (input only), eg.
  2364 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2365 
  2366 * The special syntax for function "filter" has changed from [x :
  2367 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2368 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2369 
  2370 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2371 defined on nat only, as an abbreviation for [a..<Suc b]
  2372 INCOMPATIBILITY.
  2373 
  2374 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2375 
  2376 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2377 
  2378 * New lemma collection field_simps (an extension of ring_simps) for
  2379 manipulating (in)equations involving division. Multiplies with all
  2380 denominators that can be proved to be non-zero (in equations) or
  2381 positive/negative (in inequations).
  2382 
  2383 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2384 have been improved and renamed to ring_simps, group_simps and
  2385 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2386 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2387 
  2388 * Theory Library/Commutative_Ring: switched from recdef to function
  2389 package; constants add, mul, pow now curried.  Infix syntax for
  2390 algebraic operations.
  2391 
  2392 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2393 INCOMPATIBILITY.
  2394 
  2395 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2396 INCOMPATIBILITY.
  2397 
  2398 * HOL/records: generalised field-update to take a function on the
  2399 field rather than the new value: r(|A := x|) is translated to A_update
  2400 (K x) r The K-combinator that is internally used is called K_record.
  2401 INCOMPATIBILITY: Usage of the plain update functions has to be
  2402 adapted.
  2403  
  2404 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2405 * x = 0, which are required for a semiring.  Richer structures do not
  2406 inherit from semiring_0 anymore, because this property is a theorem
  2407 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2408 there is more to prove, but this is mostly trivial.
  2409 
  2410 * Class "recpower" is generalized to arbitrary monoids, not just
  2411 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2412 commutativity or semiring properties additionally.
  2413 
  2414 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2415 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2416 better use 'abbreviation'.
  2417 
  2418 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2419 
  2420 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2421 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2422 significant changes for setting up numeral syntax for types:
  2423   - New constants Numeral.pred and Numeral.succ instead
  2424       of former Numeral.bin_pred and Numeral.bin_succ.
  2425   - Use integer operations instead of bin_add, bin_mult and so on.
  2426   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2427   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2428 
  2429 See src/HOL/Integ/IntArith.thy for an example setup.
  2430 
  2431 * Command 'normal_form' computes the normal form of a term that may
  2432 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2433 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2434 heavy-duty computations because the functions are compiled to ML
  2435 first.  Correspondingly, a method "normalization" is provided.  See
  2436 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2437 
  2438 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2439 25 like -->); output depends on the "iff" print_mode, the default is
  2440 "A = B" (with priority 50).
  2441 
  2442 * Relations less (<) and less_eq (<=) are also available on type bool.
  2443 Modified syntax to disallow nesting without explicit parentheses,
  2444 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2445 INCOMPATIBILITY.
  2446 
  2447 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2448 
  2449 * Relation composition operator "op O" now has precedence 75 and binds
  2450 stronger than union and intersection. INCOMPATIBILITY.
  2451 
  2452 * The old set interval syntax "{m..n(}" (and relatives) has been
  2453 removed.  Use "{m..<n}" (and relatives) instead.
  2454 
  2455 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2456 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2457 ``declare [[simproc del: neq]]''.
  2458 
  2459 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2460 True/False.
  2461 
  2462 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2463 
  2464 * Theorem setsum_mult renamed to setsum_right_distrib.
  2465 
  2466 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2467 ``rule'' method.
  2468 
  2469 * Reimplemented methods "sat" and "satx", with several improvements:
  2470 goals no longer need to be stated as "<prems> ==> False", equivalences
  2471 (i.e. "=" on type bool) are handled, variable names of the form
  2472 "lit_<n>" are no longer reserved, significant speedup.
  2473 
  2474 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2475 zChaff is still supported as well.
  2476 
  2477 * 'inductive' and 'datatype': provide projections of mutual rules,
  2478 bundled as foo_bar.inducts;
  2479 
  2480 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2481 Library.
  2482 
  2483 * Library: moved theory Accessible_Part to main HOL.
  2484 
  2485 * Library: added theory Coinductive_List of potentially infinite lists
  2486 as greatest fixed-point.
  2487 
  2488 * Library: added theory AssocList which implements (finite) maps as
  2489 association lists.
  2490 
  2491 * Method "evaluation" solves goals (i.e. a boolean expression)
  2492 efficiently by compiling it to ML.  The goal is "proved" (via an
  2493 oracle) if it evaluates to True.
  2494 
  2495 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2496 also when invoked by the simplifier.  This results in the Simplifier
  2497 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2498 Configuration option fast_arith_split_limit=0 recovers the old
  2499 behavior.
  2500 
  2501 * Support for hex (0x20) and binary (0b1001) numerals.
  2502 
  2503 * New method: reify eqs (t), where eqs are equations for an
  2504 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2505 parameter, computes a term s::'b and a list xs::'a list and proves the
  2506 theorem I xs s = t. This is also known as reification or quoting. The
  2507 resulting theorem is applied to the subgoal to substitute t with I xs
  2508 s.  If t is omitted, the subgoal itself is reified.
  2509 
  2510 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2511 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2512 where f is supposed to be a computable function (in the sense of code
  2513 generattion). The method uses reify to compute s and xs as above then
  2514 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2515 r and finally gets the theorem t = r, which is again applied to the
  2516 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2517 
  2518 * Reflection: Automatic reification now handels binding, an example is
  2519 available in src/HOL/ex/ReflectionEx.thy
  2520 
  2521 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2522 command 'statespace' that is similar to 'record', but introduces an
  2523 abstract specification based on the locale infrastructure instead of
  2524 HOL types.  This leads to extra flexibility in composing state spaces,
  2525 in particular multiple inheritance and renaming of components.
  2526 
  2527 
  2528 *** HOL-Complex ***
  2529 
  2530 * Hyperreal: Functions root and sqrt are now defined on negative real
  2531 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2532 Nonnegativity side conditions have been removed from many lemmas, so
  2533 that more subgoals may now be solved by simplification; potential
  2534 INCOMPATIBILITY.
  2535 
  2536 * Real: new type classes formalize real normed vector spaces and
  2537 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2538 and norm :: 'a => real.
  2539 
  2540 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2541 reals into other types. The overloaded constant Reals :: 'a set is now
  2542 defined as range of_real; potential INCOMPATIBILITY.
  2543 
  2544 * Real: proper support for ML code generation, including 'quickcheck'.
  2545 Reals are implemented as arbitrary precision rationals.
  2546 
  2547 * Hyperreal: Several constants that previously worked only for the
  2548 reals have been generalized, so they now work over arbitrary vector
  2549 spaces. Type annotations may need to be added in some cases; potential
  2550 INCOMPATIBILITY.
  2551 
  2552   Infinitesimal  :: ('a::real_normed_vector) star set
  2553   HFinite        :: ('a::real_normed_vector) star set
  2554   HInfinite      :: ('a::real_normed_vector) star set
  2555   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2556   monad          :: ('a::real_normed_vector) star => 'a star set
  2557   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2558   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2559   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2560   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2561   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2562   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2563   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2564   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2565   sgn            :: 'a::real_normed_vector => 'a
  2566   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2567 
  2568 * Complex: Some complex-specific constants are now abbreviations for
  2569 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2570 hnorm.  Other constants have been entirely removed in favor of the
  2571 polymorphic versions (INCOMPATIBILITY):
  2572 
  2573   approx        <-- capprox
  2574   HFinite       <-- CFinite
  2575   HInfinite     <-- CInfinite
  2576   Infinitesimal <-- CInfinitesimal
  2577   monad         <-- cmonad
  2578   galaxy        <-- cgalaxy
  2579   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2580   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2581   (ns)deriv     <-- (ns)cderiv
  2582 
  2583 
  2584 *** HOL-Algebra ***
  2585 
  2586 * Formalisation of ideals and the quotient construction over rings.
  2587 
  2588 * Order and lattice theory no longer based on records.
  2589 INCOMPATIBILITY.
  2590 
  2591 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2592 greatest_closed.  INCOMPATIBILITY.
  2593 
  2594 * Method algebra is now set up via an attribute.  For examples see
  2595 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2596 of algebraic structures.
  2597 
  2598 * Renamed theory CRing to Ring.
  2599 
  2600 
  2601 *** HOL-Nominal ***
  2602 
  2603 * Substantial, yet incomplete support for nominal datatypes (binding
  2604 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2605 src/HOL/Nominal/Examples.  Prospective users should consult
  2606 http://isabelle.in.tum.de/nominal/
  2607 
  2608 
  2609 *** ML ***
  2610 
  2611 * ML basics: just one true type int, which coincides with IntInf.int
  2612 (even on SML/NJ).
  2613 
  2614 * ML within Isar: antiquotations allow to embed statically-checked
  2615 formal entities in the source, referring to the context available at
  2616 compile-time.  For example:
  2617 
  2618 ML {* @{sort "{zero,one}"} *}
  2619 ML {* @{typ "'a => 'b"} *}
  2620 ML {* @{term "%x. x"} *}
  2621 ML {* @{prop "x == y"} *}
  2622 ML {* @{ctyp "'a => 'b"} *}
  2623 ML {* @{cterm "%x. x"} *}
  2624 ML {* @{cprop "x == y"} *}
  2625 ML {* @{thm asm_rl} *}
  2626 ML {* @{thms asm_rl} *}
  2627 ML {* @{type_name c} *}
  2628 ML {* @{type_syntax c} *}
  2629 ML {* @{const_name c} *}
  2630 ML {* @{const_syntax c} *}
  2631 ML {* @{context} *}
  2632 ML {* @{theory} *}
  2633 ML {* @{theory Pure} *}
  2634 ML {* @{theory_ref} *}
  2635 ML {* @{theory_ref Pure} *}
  2636 ML {* @{simpset} *}
  2637 ML {* @{claset} *}
  2638 ML {* @{clasimpset} *}
  2639 
  2640 The same works for sources being ``used'' within an Isar context.
  2641 
  2642 * ML in Isar: improved error reporting; extra verbosity with
  2643 ML_Context.trace enabled.
  2644 
  2645 * Pure/General/table.ML: the join operations now works via exceptions
  2646 DUP/SAME instead of type option. This is simpler in simple cases, and
  2647 admits slightly more efficient complex applications.
  2648 
  2649 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2650 use Context.generic instead of just theory.
  2651 
  2652 * Pure: datatype Context.generic joins theory/Proof.context and
  2653 provides some facilities for code that works in either kind of
  2654 context, notably GenericDataFun for uniform theory and proof data.
  2655 
  2656 * Pure: simplified internal attribute type, which is now always
  2657 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2658 local (Proof.context) attributes have been discontinued, while
  2659 minimizing code duplication. Thm.rule_attribute and
  2660 Thm.declaration_attribute build canonical attributes; see also structure
  2661 Context for further operations on Context.generic, notably
  2662 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2663 declarations and definitions.
  2664 
  2665 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2666 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2667 init only required for impure data. INCOMPATIBILITY: empty really need
  2668 to be empty (no dependencies on theory content!)
  2669 
  2670 * Pure/kernel: consts certification ignores sort constraints given in
  2671 signature declarations. (This information is not relevant to the
  2672 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2673 potential INCOMPATIBILITY.
  2674 
  2675 * Pure: axiomatic type classes are now purely definitional, with
  2676 explicit proofs of class axioms and super class relations performed
  2677 internally. See Pure/axclass.ML for the main internal interfaces --
  2678 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2679 AxClass.axiomatize_class/classrel/arity supersede
  2680 Sign.add_classes/classrel/arities.
  2681 
  2682 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2683 global/local versions on theory vs. Proof.context have been
  2684 discontinued; Attrib.syntax and Method.syntax have been adapted
  2685 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2686 attributes, methods, etc.
  2687 
  2688 * Pure: several functions of signature "... -> theory -> theory * ..."
  2689 have been reoriented to "... -> theory -> ... * theory" in order to
  2690 allow natural usage in combination with the ||>, ||>>, |-> and
  2691 fold_map combinators.
  2692 
  2693 * Pure: official theorem names (closed derivations) and additional
  2694 comments (tags) are now strictly separate.  Name hints -- which are
  2695 maintained as tags -- may be attached any time without affecting the
  2696 derivation.
  2697 
  2698 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2699 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2700 achieve the old behaviour.
  2701 
  2702 * Pure: the "Goal" constant is now called "prop", supporting a
  2703 slightly more general idea of ``protecting'' meta-level rule
  2704 statements.
  2705 
  2706 * Pure: Logic.(un)varify only works in a global context, which is now
  2707 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2708 Logic.legacy_(un)varify as temporary workaround.
  2709 
  2710 * Pure: structure Name provides scalable operations for generating
  2711 internal variable names, notably Name.variants etc.  This replaces
  2712 some popular functions from term.ML:
  2713 
  2714   Term.variant		->  Name.variant
  2715   Term.variantlist	->  Name.variant_list
  2716   Term.invent_names	->  Name.invent_list
  2717 
  2718 Note that low-level renaming rarely occurs in new code -- operations
  2719 from structure Variable are used instead (see below).
  2720 
  2721 * Pure: structure Variable provides fundamental operations for proper
  2722 treatment of fixed/schematic variables in a context.  For example,
  2723 Variable.import introduces fixes for schematics of given facts and
  2724 Variable.export reverses the effect (up to renaming) -- this replaces
  2725 various freeze_thaw operations.
  2726 
  2727 * Pure: structure Goal provides simple interfaces for
  2728 init/conclude/finish and tactical prove operations (replacing former
  2729 Tactic.prove).  Goal.prove is the canonical way to prove results
  2730 within a given context; Goal.prove_global is a degraded version for
  2731 theory level goals, including a global Drule.standard.  Note that
  2732 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2733 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2734 in a locale context).
  2735 
  2736 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2737 and type checking (Syntax.check_term etc.), with common combinations
  2738 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2739 which are considered legacy and await removal.
  2740 
  2741 * Pure/Syntax: generic interfaces for type unchecking
  2742 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2743 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2744 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2745 available for convenience, but refer to the very same operations using
  2746 a mere theory instead of a full context.
  2747 
  2748 * Isar: simplified treatment of user-level errors, using exception
  2749 ERROR of string uniformly.  Function error now merely raises ERROR,
  2750 without any side effect on output channels.  The Isar toplevel takes
  2751 care of proper display of ERROR exceptions.  ML code may use plain
  2752 handle/can/try; cat_error may be used to concatenate errors like this:
  2753 
  2754   ... handle ERROR msg => cat_error msg "..."
  2755 
  2756 Toplevel ML code (run directly or through the Isar toplevel) may be
  2757 embedded into the Isar toplevel with exception display/debug like
  2758 this:
  2759 
  2760   Isar.toplevel (fn () => ...)
  2761 
  2762 INCOMPATIBILITY, removed special transform_error facilities, removed
  2763 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2764 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2765 -- use plain ERROR instead.
  2766 
  2767 * Isar: theory setup now has type (theory -> theory), instead of a
  2768 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2769 
  2770 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2771 ProofContext.debug/verbose flags.
  2772 
  2773 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2774 theory before entering a proof state.  Transactions now always see a
  2775 quasi-functional intermediate checkpoint, both in interactive and
  2776 batch mode.
  2777 
  2778 * Isar: simplified interfaces for outer syntax.  Renamed
  2779 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2780 OuterSyntax.add_parsers -- this functionality is now included in
  2781 OuterSyntax.command etc.  INCOMPATIBILITY.
  2782 
  2783 * Simplifier: the simpset of a running simplification process now
  2784 contains a proof context (cf. Simplifier.the_context), which is the
  2785 very context that the initial simpset has been retrieved from (by
  2786 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2787 (solver, looper etc.) may depend on arbitrary proof data.
  2788 
  2789 * Simplifier.inherit_context inherits the proof context (plus the
  2790 local bounds) of the current simplification process; any simproc
  2791 etc. that calls the Simplifier recursively should do this!  Removed
  2792 former Simplifier.inherit_bounds, which is already included here --
  2793 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2794 specify an explicit context using Simplifier.context/theory_context.
  2795 
  2796 * Simplifier/Classical Reasoner: more abstract interfaces
  2797 change_simpset/claset for modifying the simpset/claset reference of a
  2798 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2799 INCOMPATIBILITY.
  2800 
  2801 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2802 "Trueprop" etc.
  2803 
  2804 
  2805 *** System ***
  2806 
  2807 * settings: the default heap location within ISABELLE_HOME_USER now
  2808 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2809 Isabelle installations.
  2810 
  2811 * isabelle-process: option -S (secure mode) disables some critical
  2812 operations, notably runtime compilation and evaluation of ML source
  2813 code.
  2814 
  2815 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2816 
  2817 * Support for parallel execution, using native multicore support of
  2818 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2819 independent theories, according to the given theory header
  2820 specifications. The maximum number of worker threads is specified via
  2821 usedir option -M or the "max-threads" setting in Proof General. A
  2822 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2823 to 6 on a 8-core machine.  User-code needs to observe certain
  2824 guidelines for thread-safe programming, see appendix A in the Isar
  2825 Implementation manual.
  2826 
  2827 
  2828 
  2829 New in Isabelle2005 (October 2005)
  2830 ----------------------------------
  2831 
  2832 *** General ***
  2833 
  2834 * Theory headers: the new header syntax for Isar theories is
  2835 
  2836   theory <name>
  2837   imports <theory1> ... <theoryN>
  2838   uses <file1> ... <fileM>
  2839   begin
  2840 
  2841 where the 'uses' part is optional.  The previous syntax
  2842 
  2843   theory <name> = <theory1> + ... + <theoryN>:
  2844 
  2845 will disappear in the next release.  Use isatool fixheaders to convert
  2846 existing theory files.  Note that there is no change in ancient
  2847 non-Isar theories now, but these will disappear soon.
  2848 
  2849 * Theory loader: parent theories can now also be referred to via
  2850 relative and absolute paths.
  2851 
  2852 * Command 'find_theorems' searches for a list of criteria instead of a
  2853 list of constants. Known criteria are: intro, elim, dest, name:string,
  2854 simp:term, and any term. Criteria can be preceded by '-' to select
  2855 theorems that do not match. Intro, elim, dest select theorems that
  2856 match the current goal, name:s selects theorems whose fully qualified
  2857 name contain s, and simp:term selects all simplification rules whose
  2858 lhs match term.  Any other term is interpreted as pattern and selects
  2859 all theorems matching the pattern. Available in ProofGeneral under
  2860 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2861 
  2862   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2863 
  2864 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2865 matching the current goal as introduction rule and not having "HOL."
  2866 in their name (i.e. not being defined in theory HOL).
  2867 
  2868 * Command 'thms_containing' has been discontinued in favour of
  2869 'find_theorems'; INCOMPATIBILITY.
  2870 
  2871 * Communication with Proof General is now 8bit clean, which means that
  2872 Unicode text in UTF-8 encoding may be used within theory texts (both
  2873 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2874 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2875 
  2876   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2877   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2878 
  2879 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2880 Classical Reasoner.  Typical big applications run around 2 times
  2881 faster.
  2882 
  2883 
  2884 *** Document preparation ***
  2885 
  2886 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2887 of raw sources.  Only those symbols that do not require additional
  2888 LaTeX packages (depending on comments in isabellesym.sty) are
  2889 displayed properly, everything else is left verbatim.  isatool display
  2890 and isatool print are used as front ends (these are subject to the
  2891 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2892 
  2893 * Command tags control specific markup of certain regions of text,
  2894 notably folding and hiding.  Predefined tags include "theory" (for
  2895 theory begin and end), "proof" for proof commands, and "ML" for
  2896 commands involving ML code; the additional tags "visible" and
  2897 "invisible" are unused by default.  Users may give explicit tag
  2898 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2899 interpretation of tags is determined by the LaTeX job during document
  2900 preparation: see option -V of isatool usedir, or options -n and -t of
  2901 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2902 \isadroptag.
  2903 
  2904 Several document versions may be produced at the same time via isatool
  2905 usedir (the generated index.html will link all of them).  Typical
  2906 specifications include ''-V document=theory,proof,ML'' to present
  2907 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2908 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2909 these parts without any formal replacement text.  The Isabelle site
  2910 default settings produce ''document'' and ''outline'' versions as
  2911 specified above.
  2912 
  2913 * Several new antiquotations:
  2914 
  2915   @{term_type term} prints a term with its type annotated;
  2916 
  2917   @{typeof term} prints the type of a term;
  2918 
  2919   @{const const} is the same as @{term const}, but checks that the
  2920   argument is a known logical constant;
  2921 
  2922   @{term_style style term} and @{thm_style style thm} print a term or
  2923   theorem applying a "style" to it
  2924 
  2925   @{ML text}
  2926 
  2927 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2928 definitions, equations, inequations etc., 'concl' printing only the
  2929 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2930 to print the specified premise.  TermStyle.add_style provides an ML
  2931 interface for introducing further styles.  See also the "LaTeX Sugar"
  2932 document practical applications.  The ML antiquotation prints
  2933 type-checked ML expressions verbatim.
  2934 
  2935 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2936 and 'text' support optional locale specification '(in loc)', which
  2937 specifies the default context for interpreting antiquotations.  For
  2938 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2939 
  2940 * Option 'locale=NAME' of antiquotations specifies an alternative
  2941 context interpreting the subsequent argument.  For example: @{thm
  2942 [locale=lattice] inf_assoc}.
  2943 
  2944 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2945 a proof context.
  2946 
  2947 * Proper output of antiquotations for theory commands involving a
  2948 proof context (such as 'locale' or 'theorem (in loc) ...').
  2949 
  2950 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2951 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2952 
  2953 * isatool usedir: new option -C (default true) controls whether option
  2954 -D should include a copy of the original document directory; -C false
  2955 prevents unwanted effects such as copying of administrative CVS data.
  2956 
  2957 
  2958 *** Pure ***
  2959 
  2960 * Considerably improved version of 'constdefs' command.  Now performs
  2961 automatic type-inference of declared constants; additional support for
  2962 local structure declarations (cf. locales and HOL records), see also
  2963 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2964 sequential dependencies of definitions within a single 'constdefs'
  2965 section; moreover, the declared name needs to be an identifier.  If
  2966 all fails, consider to fall back on 'consts' and 'defs' separately.
  2967 
  2968 * Improved indexed syntax and implicit structures.  First of all,
  2969 indexed syntax provides a notational device for subscripted
  2970 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2971 expressions.  Secondly, in a local context with structure
  2972 declarations, number indexes \<^sub>n or the empty index (default
  2973 number 1) refer to a certain fixed variable implicitly; option
  2974 show_structs controls printing of implicit structures.  Typical
  2975 applications of these concepts involve record types and locales.
  2976 
  2977 * New command 'no_syntax' removes grammar declarations (and
  2978 translations) resulting from the given syntax specification, which is
  2979 interpreted in the same manner as for the 'syntax' command.
  2980 
  2981 * 'Advanced' translation functions (parse_translation etc.) may depend
  2982 on the signature of the theory context being presently used for
  2983 parsing/printing, see also isar-ref manual.
  2984 
  2985 * Improved 'oracle' command provides a type-safe interface to turn an
  2986 ML expression of type theory -> T -> term into a primitive rule of
  2987 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2988 is already included here); see also FOL/ex/IffExample.thy;
  2989 INCOMPATIBILITY.
  2990 
  2991 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2992 before); "cI" is no longer bound, use "c.intro" instead.
  2993 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2994 axclasses vs. locales.
  2995 
  2996 * Improved internal renaming of symbolic identifiers -- attach primes
  2997 instead of base 26 numbers.
  2998 
  2999 * New flag show_question_marks controls printing of leading question
  3000 marks in schematic variable names.
  3001 
  3002 * In schematic variable names, *any* symbol following \<^isub> or
  3003 \<^isup> is now treated as part of the base name.  For example, the
  3004 following works without printing of awkward ".0" indexes:
  3005 
  3006   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3007     by simp
  3008 
  3009 * Inner syntax includes (*(*nested*) comments*).
  3010 
  3011 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3012 annotations as "(00...)".
  3013 
  3014 * Clear separation of logical types and nonterminals, where the latter
  3015 may only occur in 'syntax' specifications or type abbreviations.
  3016 Before that distinction was only partially implemented via type class
  3017 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3018 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3019 exotic syntax specifications may require further adaption
  3020 (e.g. Cube/Cube.thy).
  3021 
  3022 * Removed obsolete type class "logic", use the top sort {} instead.
  3023 Note that non-logical types should be declared as 'nonterminals'
  3024 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3025 specifications.
  3026 
  3027 * Attributes 'induct' and 'cases': type or set names may now be
  3028 locally fixed variables as well.
  3029 
  3030 * Simplifier: can now control the depth to which conditional rewriting
  3031 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3032 Limit.
  3033 
  3034 * Simplifier: simplification procedures may now take the current
  3035 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3036 interface), which is very useful for calling the Simplifier
  3037 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3038 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3039 low-level mk_simproc no longer applies Logic.varify internally, to
  3040 allow for use in a context of fixed variables.
  3041 
  3042 * thin_tac now works even if the assumption being deleted contains !!
  3043 or ==>.  More generally, erule now works even if the major premise of
  3044 the elimination rule contains !! or ==>.
  3045 
  3046 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3047 
  3048 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3049 from Pure, which contains all common declarations already.  Both
  3050 theories are defined via plain Isabelle/Isar .thy files.
  3051 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3052 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3053 use isatool fixcpure to adapt your theory and ML sources.
  3054 
  3055 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3056 selections of theorems in named facts via index ranges.
  3057 
  3058 * 'print_theorems': in theory mode, really print the difference
  3059 wrt. the last state (works for interactive theory development only),
  3060 in proof mode print all local facts (cf. 'print_facts');
  3061 
  3062 * 'hide': option '(open)' hides only base names.
  3063 
  3064 * More efficient treatment of intermediate checkpoints in interactive
  3065 theory development.
  3066 
  3067 * Code generator is now invoked via code_module (incremental code
  3068 generation) and code_library (modular code generation, ML structures
  3069 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3070 must be quoted when used as identifiers.
  3071 
  3072 * New 'value' command for reading, evaluating and printing terms using
  3073 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3074 quoted when used as identifier.
  3075 
  3076 
  3077 *** Locales ***
  3078 
  3079 * New commands for the interpretation of locale expressions in
  3080 theories (1), locales (2) and proof contexts (3).  These generate
  3081 proof obligations from the expression specification.  After the
  3082 obligations have been discharged, theorems of the expression are added
  3083 to the theory, target locale or proof context.  The synopsis of the
  3084 commands is a follows:
  3085 
  3086   (1) interpretation expr inst
  3087   (2) interpretation target < expr
  3088   (3) interpret expr inst
  3089 
  3090 Interpretation in theories and proof contexts require a parameter
  3091 instantiation of terms from the current context.  This is applied to
  3092 specifications and theorems of the interpreted expression.
  3093 Interpretation in locales only permits parameter renaming through the
  3094 locale expression.  Interpretation is smart in that interpretations
  3095 that are active already do not occur in proof obligations, neither are
  3096 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3097 inspect active interpretations of a particular locale.  For details,
  3098 see the Isar Reference manual.  Examples can be found in
  3099 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3100 
  3101 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3102 'interpret' instead.
  3103 
  3104 * New context element 'constrains' for adding type constraints to
  3105 parameters.
  3106 
  3107 * Context expressions: renaming of parameters with syntax
  3108 redeclaration.
  3109 
  3110 * Locale declaration: 'includes' disallowed.
  3111 
  3112 * Proper static binding of attribute syntax -- i.e. types / terms /
  3113 facts mentioned as arguments are always those of the locale definition
  3114 context, independently of the context of later invocations.  Moreover,
  3115 locale operations (renaming and type / term instantiation) are applied
  3116 to attribute arguments as expected.
  3117 
  3118 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3119 actual attributes; rare situations may require Attrib.attribute to
  3120 embed those attributes into Attrib.src that lack concrete syntax.
  3121 Attribute implementations need to cooperate properly with the static
  3122 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3123 Attrib.XXX_thm etc. already do the right thing without further
  3124 intervention.  Only unusual applications -- such as "where" or "of"
  3125 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3126 on the context and the facts involved -- may have to assign parsed
  3127 values to argument tokens explicitly.
  3128 
  3129 * Changed parameter management in theorem generation for long goal
  3130 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3131 theorem statement in rare situations.
  3132 
  3133 * Locale inspection command 'print_locale' omits notes elements.  Use
  3134 'print_locale!' to have them included in the output.
  3135 
  3136 
  3137 *** Provers ***
  3138 
  3139 * Provers/hypsubst.ML: improved version of the subst method, for
  3140 single-step rewriting: it now works in bound variable contexts. New is
  3141 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3142 rewrite a different subterm than the original subst method, which is
  3143 still available as 'simplesubst'.
  3144 
  3145 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3146 and quasi orders.
  3147 
  3148 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3149 reflexive-transitive closure of relations.
  3150 
  3151 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3152 limit (previously hard-coded with a value of 20) user-definable.
  3153 
  3154 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3155 is peformed already.  Object-logics merely need to finish their
  3156 initial simpset configuration as before.  INCOMPATIBILITY.
  3157 
  3158 
  3159 *** HOL ***
  3160 
  3161 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3162 
  3163   syntax (epsilon)
  3164     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3165 
  3166 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3167 and x-symbol; use option '-m epsilon' to get it actually printed.
  3168 Moreover, the mathematically important symbolic identifier \<epsilon>
  3169 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3170 
  3171 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3172 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3173 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3174 support corresponding Isar calculations.
  3175 
  3176 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3177 instead of ":".
  3178 
  3179 * theory SetInterval: changed the syntax for open intervals:
  3180 
  3181   Old       New
  3182   {..n(}    {..<n}
  3183   {)n..}    {n<..}
  3184   {m..n(}   {m..<n}
  3185   {)m..n}   {m<..n}
  3186   {)m..n(}  {m<..<n}
  3187 
  3188 The old syntax is still supported but will disappear in the next
  3189 release.  For conversion use the following Emacs search and replace
  3190 patterns (these are not perfect but work quite well):
  3191 
  3192   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3193   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3194 
  3195 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3196 equalities in commutative rings; method 'algebra' provides a generic
  3197 interface.
  3198 
  3199 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3200 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3201 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3202 be a tuple pattern.
  3203 
  3204 Some new syntax forms are available:
  3205 
  3206   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3207   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3208   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3209   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3210 
  3211 The latter form "\<Sum>x < k. e" used to be based on a separate
  3212 function "Summation", which has been discontinued.
  3213 
  3214 * theory Finite_Set: in structured induction proofs, the insert case
  3215 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3216 (insert F x)'.
  3217 
  3218 * The 'refute' command has been extended to support a much larger
  3219 fragment of HOL, including axiomatic type classes, constdefs and
  3220 typedefs, inductive datatypes and recursion.
  3221 
  3222 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3223 Requires zChaff with proof generation to be installed.  See
  3224 HOL/ex/SAT_Examples.thy for examples.
  3225 
  3226 * Datatype induction via method 'induct' now preserves the name of the
  3227 induction variable. For example, when proving P(xs::'a list) by
  3228 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3229 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3230 in unstructured proof scripts.
  3231 
  3232 * Reworked implementation of records.  Improved scalability for
  3233 records with many fields, avoiding performance problems for type
  3234 inference. Records are no longer composed of nested field types, but
  3235 of nested extension types. Therefore the record type only grows linear
  3236 in the number of extensions and not in the number of fields.  The
  3237 top-level (users) view on records is preserved.  Potential
  3238 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3239 old record representation. The type generated for a record is called
  3240 <record_name>_ext_type.
  3241 
  3242 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3243 proofs triggered by a record definition or a simproc (if
  3244 quick_and_dirty is enabled).  Definitions of large records can take
  3245 quite long.
  3246 
  3247 New simproc record_upd_simproc for simplification of multiple record
  3248 updates enabled by default.  Moreover, trivial updates are also
  3249 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3250 occasionally, since simplification is more powerful by default.
  3251 
  3252 * typedef: proper support for polymorphic sets, which contain extra
  3253 type-variables in the term.
  3254 
  3255 * Simplifier: automatically reasons about transitivity chains
  3256 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3257 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3258 old proofs break occasionally as simplification may now solve more
  3259 goals than previously.
  3260 
  3261 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3262 present.  Works for all partial orders (class "order"), in particular
  3263 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3264 just like y <= x.
  3265 
  3266 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3267 bound variable or a constant then the let is unfolded.  Otherwise
  3268 first a is simplified to b, and then f b is simplified to g. If
  3269 possible we abstract b from g arriving at "let x = b in h x",
  3270 otherwise we unfold the let and arrive at g.  The simproc can be
  3271 enabled/disabled by the reference use_let_simproc.  Potential
  3272 INCOMPATIBILITY since simplification is more powerful by default.
  3273 
  3274 * Classical reasoning: the meson method now accepts theorems as arguments.
  3275 
  3276 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3277 jobs to provide advice on the provability of subgoals.
  3278 
  3279 * Theory OrderedGroup and Ring_and_Field: various additions and
  3280 improvements to faciliate calculations involving equalities and
  3281 inequalities.
  3282 
  3283 The following theorems have been eliminated or modified
  3284 (INCOMPATIBILITY):
  3285 
  3286   abs_eq             now named abs_of_nonneg
  3287   abs_of_ge_0        now named abs_of_nonneg
  3288   abs_minus_eq       now named abs_of_nonpos
  3289   imp_abs_id         now named abs_of_nonneg
  3290   imp_abs_neg_id     now named abs_of_nonpos
  3291   mult_pos           now named mult_pos_pos
  3292   mult_pos_le        now named mult_nonneg_nonneg
  3293   mult_pos_neg_le    now named mult_nonneg_nonpos
  3294   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3295   mult_neg           now named mult_neg_neg
  3296   mult_neg_le        now named mult_nonpos_nonpos
  3297 
  3298 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3299      
  3300      zero_le_square
  3301      not_square_less_zero 
  3302 
  3303   The following lemmas have been deleted from Real/RealPow:
  3304   
  3305      realpow_zero_zero
  3306      realpow_two
  3307      realpow_less
  3308      zero_le_power
  3309      realpow_two_le
  3310      abs_realpow_two
  3311      realpow_two_abs     
  3312 
  3313 * Theory Parity: added rules for simplifying exponents.
  3314 
  3315 * Theory List:
  3316 
  3317 The following theorems have been eliminated or modified
  3318 (INCOMPATIBILITY):
  3319 
  3320   list_all_Nil       now named list_all.simps(1)
  3321   list_all_Cons      now named list_all.simps(2)
  3322   list_all_conv      now named list_all_iff
  3323   set_mem_eq         now named mem_iff
  3324 
  3325 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3326 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3327 
  3328 
  3329 *** HOL-Complex ***
  3330 
  3331 * Theory RealDef: better support for embedding natural numbers and
  3332 integers in the reals.
  3333 
  3334 The following theorems have been eliminated or modified
  3335 (INCOMPATIBILITY):
  3336 
  3337   exp_ge_add_one_self  now requires no hypotheses
  3338   real_of_int_add      reversed direction of equality (use [symmetric])
  3339   real_of_int_minus    reversed direction of equality (use [symmetric])
  3340   real_of_int_diff     reversed direction of equality (use [symmetric])
  3341   real_of_int_mult     reversed direction of equality (use [symmetric])
  3342 
  3343 * Theory RComplete: expanded support for floor and ceiling functions.
  3344 
  3345 * Theory Ln is new, with properties of the natural logarithm
  3346 
  3347 * Hyperreal: There is a new type constructor "star" for making
  3348 nonstandard types.  The old type names are now type synonyms:
  3349 
  3350   hypreal = real star
  3351   hypnat = nat star
  3352   hcomplex = complex star
  3353 
  3354 * Hyperreal: Many groups of similarly-defined constants have been
  3355 replaced by polymorphic versions (INCOMPATIBILITY):
  3356 
  3357   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3358 
  3359   starset      <-- starsetNat, starsetC
  3360   *s*          <-- *sNat*, *sc*
  3361   starset_n    <-- starsetNat_n, starsetC_n
  3362   *sn*         <-- *sNatn*, *scn*
  3363   InternalSets <-- InternalNatSets, InternalCSets
  3364 
  3365   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3366   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3367   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3368   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3369   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3370 
  3371 * Hyperreal: Many type-specific theorems have been removed in favor of
  3372 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3373 
  3374   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3375   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3376   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3377   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3378   right_minus <-- hypreal_add_minus
  3379   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3380   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3381   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3382   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3383   mult_1_right <-- hcomplex_mult_one_right
  3384   mult_zero_left <-- hcomplex_mult_zero_left
  3385   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3386   right_distrib <-- hypnat_add_mult_distrib2
  3387   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3388   right_inverse <-- hypreal_mult_inverse
  3389   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3390   order_refl <-- {hypreal,hypnat}_le_refl
  3391   order_trans <-- {hypreal,hypnat}_le_trans
  3392   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3393   order_less_le <-- {hypreal,hypnat}_less_le
  3394   linorder_linear <-- {hypreal,hypnat}_le_linear
  3395   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3396   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3397   add_nonneg_nonneg <-- hypreal_le_add_order
  3398 
  3399 * Hyperreal: Separate theorems having to do with type-specific
  3400 versions of constants have been merged into theorems that apply to the
  3401 new polymorphic constants (INCOMPATIBILITY):
  3402 
  3403   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3404   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3405   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3406   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3407   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3408   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3409   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3410   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3411   STAR_diff <-- {STAR,STARC}_diff
  3412   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3413     STARC_hcomplex_of_complex}_image_subset
  3414   starset_n_Un <-- starset{Nat,C}_n_Un
  3415   starset_n_Int <-- starset{Nat,C}_n_Int
  3416   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3417   starset_n_diff <-- starset{Nat,C}_n_diff
  3418   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3419   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3420   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3421   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3422   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3423   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3424   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3425   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3426   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3427   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3428   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3429   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3430   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3431   starfun_diff <-- starfun{C,RC,CR}_diff
  3432   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3433   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3434   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3435   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3436   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3437   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3438   starfun_Id <-- starfunC_Id
  3439   starfun_approx <-- starfun{Nat,CR}_approx
  3440   starfun_capprox <-- starfun{C,RC}_capprox
  3441   starfun_abs <-- starfunNat_rabs
  3442   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3443   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3444   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3445   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3446   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3447   starfun_add_approx <-- starfunCR_add_approx
  3448   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3449   starfun_divide <-- starfun{C,CR,RC}_divide
  3450   starfun_n <-- starfun{Nat,C}_n
  3451   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3452   starfun_n_add <-- starfun{Nat,C}_n_add
  3453   starfun_n_add_minus <-- starfunNat_n_add_minus
  3454   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3455   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3456   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3457 
  3458   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3459   star_n_minus <-- {hypreal,hcomplex}_minus
  3460   star_n_diff <-- {hypreal,hcomplex}_diff
  3461   star_n_mult <-- {hypreal,hcomplex}_mult
  3462   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3463   star_n_le <-- {hypreal,hypnat}_le
  3464   star_n_less <-- {hypreal,hypnat}_less
  3465   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3466   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3467   star_n_abs <-- hypreal_hrabs
  3468   star_n_divide <-- hcomplex_divide
  3469 
  3470   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3471   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3472   star_of_diff <-- hypreal_of_real_diff
  3473   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3474   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3475   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3476   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3477   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3478   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3479   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3480   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3481   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3482   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3483   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3484   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3485   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3486   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3487   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3488   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3489   star_of_power <-- hypreal_of_real_power
  3490   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3491 
  3492 * Hyperreal: new method "transfer" that implements the transfer
  3493 principle of nonstandard analysis. With a subgoal that mentions
  3494 nonstandard types like "'a star", the command "apply transfer"
  3495 replaces it with an equivalent one that mentions only standard types.
  3496 To be successful, all free variables must have standard types; non-
  3497 standard variables must have explicit universal quantifiers.
  3498 
  3499 * Hyperreal: A theory of Taylor series.
  3500 
  3501 
  3502 *** HOLCF ***
  3503 
  3504 * Discontinued special version of 'constdefs' (which used to support
  3505 continuous functions) in favor of the general Pure one with full
  3506 type-inference.
  3507 
  3508 * New simplification procedure for solving continuity conditions; it
  3509 is much faster on terms with many nested lambda abstractions (cubic
  3510 instead of exponential time).
  3511 
  3512 * New syntax for domain package: selector names are now optional.
  3513 Parentheses should be omitted unless argument is lazy, for example:
  3514 
  3515   domain 'a stream = cons "'a" (lazy "'a stream")
  3516 
  3517 * New command 'fixrec' for defining recursive functions with pattern
  3518 matching; defining multiple functions with mutual recursion is also
  3519 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3520 sinr, or any data constructor defined by the domain package. The given
  3521 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3522 syntax and examples.
  3523 
  3524 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3525 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3526 but the proof obligation additionally includes an admissibility
  3527 requirement. The packages generate instances of class cpo or pcpo,
  3528 with continuity and strictness theorems for Rep and Abs.
  3529 
  3530 * HOLCF: Many theorems have been renamed according to a more standard naming
  3531 scheme (INCOMPATIBILITY):
  3532 
  3533   foo_inject:  "foo$x = foo$y ==> x = y"
  3534   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3535   foo_less:    "(foo$x << foo$y) = (x << y)"
  3536   foo_strict:  "foo$UU = UU"
  3537   foo_defined: "... ==> foo$x ~= UU"
  3538   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3539 
  3540 
  3541 *** ZF ***
  3542 
  3543 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3544 including the First Isomorphism Theorem (on quotienting by the kernel
  3545 of a homomorphism).
  3546 
  3547 * ZF/Simplifier: install second copy of type solver that actually
  3548 makes use of TC rules declared to Isar proof contexts (or locales);
  3549 the old version is still required for ML proof scripts.
  3550 
  3551 
  3552 *** Cube ***
  3553 
  3554 * Converted to Isar theory format; use locales instead of axiomatic
  3555 theories.
  3556 
  3557 
  3558 *** ML ***
  3559 
  3560 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3561 for ||>, ||>>, |>>,
  3562 
  3563 * Pure/library.ML no longer defines its own option datatype, but uses
  3564 that of the SML basis, which has constructors NONE and SOME instead of
  3565 None and Some, as well as exception Option.Option instead of OPTION.
  3566 The functions the, if_none, is_some, is_none have been adapted
  3567 accordingly, while Option.map replaces apsome.
  3568 
  3569 * Pure/library.ML: the exception LIST has been given up in favour of
  3570 the standard exceptions Empty and Subscript, as well as
  3571 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3572 superceded by the standard hd and tl functions etc.
  3573 
  3574 A number of basic list functions are no longer exported to the ML
  3575 toplevel, as they are variants of predefined functions.  The following
  3576 suggests how one can translate existing code:
  3577 
  3578     rev_append xs ys = List.revAppend (xs, ys)
  3579     nth_elem (i, xs) = List.nth (xs, i)
  3580     last_elem xs = List.last xs
  3581     flat xss = List.concat xss
  3582     seq fs = List.app fs
  3583     partition P xs = List.partition P xs
  3584     mapfilter f xs = List.mapPartial f xs
  3585 
  3586 * Pure/library.ML: several combinators for linear functional
  3587 transformations, notably reverse application and composition:
  3588 
  3589   x |> f                f #> g
  3590   (x, y) |-> f          f #-> g
  3591 
  3592 * Pure/library.ML: introduced/changed precedence of infix operators:
  3593 
  3594   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3595   infix 2 ?;
  3596   infix 3 o oo ooo oooo;
  3597   infix 4 ~~ upto downto;
  3598 
  3599 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3600 infix operators.
  3601 
  3602 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3603 fold_map support linear functional transformations and nesting.  For
  3604 example:
  3605 
  3606   fold f [x1, ..., xN] y =
  3607     y |> f x1 |> ... |> f xN
  3608 
  3609   (fold o fold) f [xs1, ..., xsN] y =
  3610     y |> fold f xs1 |> ... |> fold f xsN
  3611 
  3612   fold f [x1, ..., xN] =
  3613     f x1 #> ... #> f xN
  3614 
  3615   (fold o fold) f [xs1, ..., xsN] =
  3616     fold f xs1 #> ... #> fold f xsN
  3617 
  3618 * Pure/library.ML: the following selectors on type 'a option are
  3619 available:
  3620 
  3621   the:               'a option -> 'a  (*partial*)
  3622   these:             'a option -> 'a  where 'a = 'b list
  3623   the_default: 'a -> 'a option -> 'a
  3624   the_list:          'a option -> 'a list
  3625 
  3626 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3627 basic operations for association lists, following natural argument
  3628 order; moreover the explicit equality predicate passed here avoids
  3629 potentially expensive polymorphic runtime equality checks.
  3630 The old functions may be expressed as follows:
  3631 
  3632   assoc = uncurry (AList.lookup (op =))
  3633   assocs = these oo AList.lookup (op =)
  3634   overwrite = uncurry (AList.update (op =)) o swap
  3635 
  3636 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3637 
  3638   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3639   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3640 
  3641 replacing make_keylist and keyfilter (occassionally used)
  3642 Naive rewrites:
  3643 
  3644   make_keylist = AList.make
  3645   keyfilter = AList.find (op =)
  3646 
  3647 * eq_fst and eq_snd now take explicit equality parameter, thus
  3648   avoiding eqtypes. Naive rewrites:
  3649 
  3650     eq_fst = eq_fst (op =)
  3651     eq_snd = eq_snd (op =)
  3652 
  3653 * Removed deprecated apl and apr (rarely used).
  3654   Naive rewrites:
  3655 
  3656     apl (n, op) =>>= curry op n
  3657     apr (op, m) =>>= fn n => op (n, m)
  3658 
  3659 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3660 provides a reasonably efficient light-weight implementation of sets as
  3661 lists.
  3662 
  3663 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3664 few new operations; existing lookup and update are now curried to
  3665 follow natural argument order (for use with fold etc.);
  3666 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3667 
  3668 * Pure/General: output via the Isabelle channels of
  3669 writeln/warning/error etc. is now passed through Output.output, with a
  3670 hook for arbitrary transformations depending on the print_mode
  3671 (cf. Output.add_mode -- the first active mode that provides a output
  3672 function wins).  Already formatted output may be embedded into further
  3673 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3674 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3675 accommodate easy composition of diagnostic messages etc.  Programmers
  3676 rarely need to care about Output.output or Output.raw at all, with
  3677 some notable exceptions: Output.output is required when bypassing the
  3678 standard channels (writeln etc.), or in token translations to produce
  3679 properly formatted results; Output.raw is required when capturing
  3680 already output material that will eventually be presented to the user
  3681 a second time.  For the default print mode, both Output.output and
  3682 Output.raw have no effect.
  3683 
  3684 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3685 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3686 cumulative results are displayed at the end of a batch session.
  3687 
  3688 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3689 replaced by File.platform_path and File.shell_path (with appropriate
  3690 hooks).  This provides a clean interface for unusual systems where the
  3691 internal and external process view of file names are different.
  3692 
  3693 * Pure: more efficient orders for basic syntactic entities: added
  3694 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3695 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3696 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3697 orders now -- potential INCOMPATIBILITY for code that depends on a
  3698 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3699 Library.sort_strings on result).
  3700 
  3701 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3702 fold_types traverse types/terms from left to right, observing natural
  3703 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3704 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3705 
  3706 * Pure: name spaces have been refined, with significant changes of the
  3707 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3708 to extern(_table).  The plain name entry path is superceded by a
  3709 general 'naming' context, which also includes the 'policy' to produce
  3710 a fully qualified name and external accesses of a fully qualified
  3711 name; NameSpace.extend is superceded by context dependent
  3712 Sign.declare_name.  Several theory and proof context operations modify
  3713 the naming context.  Especially note Theory.restore_naming and
  3714 ProofContext.restore_naming to get back to a sane state; note that
  3715 Theory.add_path is no longer sufficient to recover from
  3716 Theory.absolute_path in particular.
  3717 
  3718 * Pure: new flags short_names (default false) and unique_names
  3719 (default true) for controlling output of qualified names.  If
  3720 short_names is set, names are printed unqualified.  If unique_names is
  3721 reset, the name prefix is reduced to the minimum required to achieve
  3722 the original result when interning again, even if there is an overlap
  3723 with earlier declarations.
  3724 
  3725 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3726 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3727 (useful for printing error messages).  INCOMPATIBILITY.
  3728 
  3729 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3730 Theory.theory are now identified, referring to the universal
  3731 Context.theory (see Pure/context.ML).  Actual signature and theory
  3732 content is managed as theory data.  The old code and interfaces were
  3733 spread over many files and structures; the new arrangement introduces
  3734 considerable INCOMPATIBILITY to gain more clarity:
  3735 
  3736   Context -- theory management operations (name, identity, inclusion,
  3737     parents, ancestors, merge, etc.), plus generic theory data;
  3738 
  3739   Sign -- logical signature and syntax operations (declaring consts,
  3740     types, etc.), plus certify/read for common entities;
  3741 
  3742   Theory -- logical theory operations (stating axioms, definitions,
  3743     oracles), plus a copy of logical signature operations (consts,
  3744     types, etc.); also a few basic management operations (Theory.copy,
  3745     Theory.merge, etc.)
  3746 
  3747 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3748 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3749 for convenience -- they merely return the theory.
  3750 
  3751 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3752 
  3753 * Pure: the Isar proof context type is already defined early in Pure
  3754 as Context.proof (note that ProofContext.context and Proof.context are
  3755 aliases, where the latter is the preferred name).  This enables other
  3756 Isabelle components to refer to that type even before Isar is present.
  3757 
  3758 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3759 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3760 any of these kinds.  For example, Sign.intern typeK is now
  3761 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3762 Theory.hide_types.  Also note that former
  3763 Theory.hide_classes/types/consts are now
  3764 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3765 internalize their arguments!  INCOMPATIBILITY.
  3766 
  3767 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3768 datatype thmref (with constructors Name and NameSelection) instead of
  3769 plain string -- INCOMPATIBILITY;
  3770 
  3771 * Pure: cases produced by proof methods specify options, where NONE
  3772 means to remove case bindings -- INCOMPATIBILITY in
  3773 (RAW_)METHOD_CASES.
  3774 
  3775 * Pure: the following operations retrieve axioms or theorems from a
  3776 theory node or theory hierarchy, respectively:
  3777 
  3778   Theory.axioms_of: theory -> (string * term) list
  3779   Theory.all_axioms_of: theory -> (string * term) list
  3780   PureThy.thms_of: theory -> (string * thm) list
  3781   PureThy.all_thms_of: theory -> (string * thm) list
  3782 
  3783 * Pure: print_tac now outputs the goal through the trace channel.
  3784 
  3785 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3786 Reference Toplevel.debug (default false) controls detailed printing
  3787 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3788 controls execution profiling -- set to 1 for time and 2 for space
  3789 (both increase the runtime).
  3790 
  3791 * Isar session: The initial use of ROOT.ML is now always timed,
  3792 i.e. the log will show the actual process times, in contrast to the
  3793 elapsed wall-clock time that the outer shell wrapper produces.
  3794 
  3795 * Simplifier: improved handling of bound variables (nameless
  3796 representation, avoid allocating new strings).  Simprocs that invoke
  3797 the Simplifier recursively should use Simplifier.inherit_bounds to
  3798 avoid local name clashes.  Failure to do so produces warnings
  3799 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3800 for further details.
  3801 
  3802 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3803 bindings for all theorems stored within a given theory; this may help
  3804 in porting non-Isar theories to Isar ones, while keeping ML proof
  3805 scripts for the time being.
  3806 
  3807 * ML operator HTML.with_charset specifies the charset begin used for
  3808 generated HTML files.  For example:
  3809 
  3810   HTML.with_charset "utf-8" use_thy "Hebrew";
  3811   HTML.with_charset "utf-8" use_thy "Chinese";
  3812 
  3813 
  3814 *** System ***
  3815 
  3816 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3817 isabelle, isatool etc.).
  3818 
  3819 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3820 isatool doc, isatool mkdir, display_drafts etc.).
  3821 
  3822 * isatool usedir: option -f allows specification of the ML file to be
  3823 used by Isabelle; default is ROOT.ML.
  3824 
  3825 * New isatool version outputs the version identifier of the Isabelle
  3826 distribution being used.
  3827 
  3828 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3829 (containing Boolean satisfiability problems) into Isabelle/HOL
  3830 theories.
  3831 
  3832 
  3833 
  3834 New in Isabelle2004 (April 2004)
  3835 --------------------------------
  3836 
  3837 *** General ***
  3838 
  3839 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3840   Replaces linorder.ML.
  3841 
  3842 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3843   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3844   (\<a>...\<z>), are now considered normal letters, and can therefore
  3845   be used anywhere where an ASCII letter (a...zA...Z) has until
  3846   now. COMPATIBILITY: This obviously changes the parsing of some
  3847   terms, especially where a symbol has been used as a binder, say
  3848   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3849   as an identifier.  Fix it by inserting a space around former
  3850   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3851   existing theory and ML files.
  3852 
  3853 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3854 
  3855 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3856   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3857   a normal (but invisible) letter. For multiple letter subscripts repeat
  3858   \<^isub> like this: x\<^isub>1\<^isub>2.
  3859 
  3860 * Pure: There are now sub-/superscripts that can span more than one
  3861   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3862   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3863   superscript. The new control characters are not identifier parts.
  3864 
  3865 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3866   content of "..." to the latex file instead of \isacntrl... . The "..."
  3867   may consist of any printable characters excluding the end bracket >.
  3868 
  3869 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3870   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3871   declare constants "final", which prevents their being given a definition
  3872   later.  It is useful for constants whose behaviour is fixed axiomatically
  3873   rather than definitionally, such as the meta-logic connectives.
  3874 
  3875 * Pure: 'instance' now handles general arities with general sorts
  3876   (i.e. intersections of classes),
  3877 
  3878 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3879   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3880   It can be changed to alter the colors/layout of generated pages.
  3881 
  3882 
  3883 *** Isar ***
  3884 
  3885 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3886   cut_tac, subgoal_tac and thin_tac:
  3887   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3888     locales are no longer forced to write Isar proof scripts.
  3889     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3890     emulations.
  3891   - INCOMPATIBILITY: names of variables to be instantiated may no
  3892     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3893     This is consistent with the instantiation attribute "where".
  3894 
  3895 * Attributes "where" and "of":
  3896   - Now take type variables of instantiated theorem into account when reading
  3897     the instantiation string.  This fixes a bug that caused instantiated
  3898     theorems to have too special types in some circumstances.
  3899   - "where" permits explicit instantiations of type variables.
  3900 
  3901 * Calculation commands "moreover" and "also" no longer interfere with
  3902   current facts ("this"), admitting arbitrary combinations with "then"
  3903   and derived forms.
  3904 
  3905 * Locales:
  3906   - Goal statements involving the context element "includes" no longer
  3907     generate theorems with internal delta predicates (those ending on
  3908     "_axioms") in the premise.
  3909     Resolve particular premise with <locale>.intro to obtain old form.
  3910   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3911     specification and "includes" elements in goal statement.
  3912   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3913     [intro?] and [elim?] (respectively) by default.
  3914   - Experimental command for instantiation of locales in proof contexts:
  3915         instantiate <label>[<attrs>]: <loc>
  3916     Instantiates locale <loc> and adds all its theorems to the current context
  3917     taking into account their attributes.  Label and attrs are optional
  3918     modifiers, like in theorem declarations.  If present, names of
  3919     instantiated theorems are qualified with <label>, and the attributes
  3920     <attrs> are applied after any attributes these theorems might have already.
  3921       If the locale has assumptions, a chained fact of the form
  3922     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3923     are derived.  The command does not support old-style locales declared
  3924     with "locale (open)".
  3925       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3926 
  3927 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3928   (Isar) contexts.
  3929 
  3930 
  3931 *** HOL ***
  3932 
  3933 * Proof import: new image HOL4 contains the imported library from
  3934   the HOL4 system with about 2500 theorems. It is imported by
  3935   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3936   can be used like any other Isabelle image.  See
  3937   HOL/Import/HOL/README for more information.
  3938 
  3939 * Simplifier:
  3940   - Much improved handling of linear and partial orders.
  3941     Reasoners for linear and partial orders are set up for type classes
  3942     "linorder" and "order" respectively, and are added to the default simpset
  3943     as solvers.  This means that the simplifier can build transitivity chains
  3944     to solve goals from the assumptions.
  3945   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3946     of blast or auto after simplification become unnecessary because the goal
  3947     is solved by simplification already.
  3948 
  3949 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3950     all proved in axiomatic type classes for semirings, rings and fields.
  3951 
  3952 * Numerics:
  3953   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3954     now formalized using the Ring_and_Field theory mentioned above.
  3955   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3956     than before, because now they are set up once in a generic manner.
  3957   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3958     Look for the general versions in Ring_and_Field (and Power if they concern
  3959     exponentiation).
  3960 
  3961 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3962 
  3963 * Records:
  3964   - Record types are now by default printed with their type abbreviation
  3965     instead of the list of all field types. This can be configured via
  3966     the reference "print_record_type_abbr".
  3967   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3968     (not enabled by default).
  3969   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3970     EX x. x = sel r to True (not enabled by default).
  3971   - Tactic "record_split_simp_tac" to split and simplify records added.
  3972 
  3973 * 'specification' command added, allowing for definition by
  3974   specification.  There is also an 'ax_specification' command that
  3975   introduces the new constants axiomatically.
  3976 
  3977 * arith(_tac) is now able to generate counterexamples for reals as well.
  3978 
  3979 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3980 
  3981 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3982   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3983 
  3984 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3985   matrix theory to linear programming.
  3986 
  3987 * Unions and Intersections:
  3988   The latex output syntax of UN and INT has been changed
  3989   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3990   i.e. the index formulae has become a subscript.
  3991   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3992 
  3993 * Unions and Intersections over Intervals:
  3994   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3995   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3996   like in normal math, and corresponding versions for < and for intersection.
  3997 
  3998 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3999   lexicographic dictonary ordering has been added as "lexord".
  4000 
  4001 * ML: the legacy theory structures Int and List have been removed. They had
  4002   conflicted with ML Basis Library structures having the same names.
  4003 
  4004 * 'refute' command added to search for (finite) countermodels.  Only works
  4005   for a fragment of HOL.  The installation of an external SAT solver is
  4006   highly recommended.  See "HOL/Refute.thy" for details.
  4007 
  4008 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4009   formulae under an assignment of free variables to random values.
  4010   In contrast to 'refute', it can deal with inductive datatypes,
  4011   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4012   for examples.
  4013 
  4014 
  4015 *** HOLCF ***
  4016 
  4017 * Streams now come with concatenation and are part of the HOLCF image
  4018 
  4019 
  4020 
  4021 New in Isabelle2003 (May 2003)
  4022 ------------------------------
  4023 
  4024 *** General ***
  4025 
  4026 * Provers/simplifier:
  4027 
  4028   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4029     Assumptions are now subject to complete mutual simplification,
  4030     not just from left to right. The simplifier now preserves
  4031     the order of assumptions.
  4032 
  4033     Potential INCOMPATIBILITY:
  4034 
  4035     -- simp sometimes diverges where the old version did
  4036        not, e.g. invoking simp on the goal
  4037 
  4038         [| P (f x); y = x; f x = f y |] ==> Q
  4039 
  4040        now gives rise to the infinite reduction sequence
  4041 
  4042         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4043 
  4044        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4045        kind of problem.
  4046 
  4047     -- Tactics combining classical reasoner and simplification (such as auto)
  4048        are also affected by this change, because many of them rely on
  4049        simp. They may sometimes diverge as well or yield a different numbers
  4050        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4051        in case of problems. Sometimes subsequent calls to the classical
  4052        reasoner will fail because a preceeding call to the simplifier too
  4053        eagerly simplified the goal, e.g. deleted redundant premises.
  4054 
  4055   - The simplifier trace now shows the names of the applied rewrite rules
  4056 
  4057   - You can limit the number of recursive invocations of the simplifier
  4058     during conditional rewriting (where the simplifie tries to solve the
  4059     conditions before applying the rewrite rule):
  4060     ML "simp_depth_limit := n"
  4061     where n is an integer. Thus you can force termination where previously
  4062     the simplifier would diverge.
  4063 
  4064   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4065 
  4066   - No longer aborts on failed congruence proof.  Instead, the
  4067     congruence is ignored.
  4068 
  4069 * Pure: New generic framework for extracting programs from constructive
  4070   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4071   as HOL/Extraction for some case studies.
  4072 
  4073 * Pure: The main goal of the proof state is no longer shown by default, only
  4074 the subgoals. This behaviour is controlled by a new flag.
  4075    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4076 (ML: Proof.show_main_goal).
  4077 
  4078 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4079 rules whose conclusion matches subgoal 1:
  4080       PG menu: Isabelle/Isar -> Show me -> matching rules
  4081 The rules are ordered by how closely they match the subgoal.
  4082 In particular, rules that solve a subgoal outright are displayed first
  4083 (or rather last, the way they are printed).
  4084 (ML: ProofGeneral.print_intros())
  4085 
  4086 * Pure: New flag trace_unify_fail causes unification to print
  4087 diagnostic information (PG: in trace buffer) when it fails. This is
  4088 useful for figuring out why single step proofs like rule, erule or
  4089 assumption failed.
  4090 
  4091 * Pure: Locale specifications now produce predicate definitions
  4092 according to the body of text (covering assumptions modulo local
  4093 definitions); predicate "loc_axioms" covers newly introduced text,
  4094 while "loc" is cumulative wrt. all included locale expressions; the
  4095 latter view is presented only on export into the global theory
  4096 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4097 on the old view without predicates;
  4098 
  4099 * Pure: predefined locales "var" and "struct" are useful for sharing
  4100 parameters (as in CASL, for example); just specify something like
  4101 ``var x + var y + struct M'' as import;
  4102 
  4103 * Pure: improved thms_containing: proper indexing of facts instead of
  4104 raw theorems; check validity of results wrt. current name space;
  4105 include local facts of proof configuration (also covers active
  4106 locales), cover fixed variables in index; may use "_" in term
  4107 specification; an optional limit for the number of printed facts may
  4108 be given (the default is 40);
  4109 
  4110 * Pure: disallow duplicate fact bindings within new-style theory files
  4111 (batch-mode only);
  4112 
  4113 * Provers: improved induct method: assumptions introduced by case
  4114 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4115 the goal statement); "foo" still refers to all facts collectively;
  4116 
  4117 * Provers: the function blast.overloaded has been removed: all constants
  4118 are regarded as potentially overloaded, which improves robustness in exchange
  4119 for slight decrease in efficiency;
  4120 
  4121 * Provers/linorder: New generic prover for transitivity reasoning over
  4122 linear orders.  Note: this prover is not efficient!
  4123 
  4124 * Isar: preview of problems to finish 'show' now produce an error
  4125 rather than just a warning (in interactive mode);
  4126 
  4127 
  4128 *** HOL ***
  4129 
  4130 * arith(_tac)
  4131 
  4132  - Produces a counter example if it cannot prove a goal.
  4133    Note that the counter example may be spurious if the goal is not a formula
  4134    of quantifier-free linear arithmetic.
  4135    In ProofGeneral the counter example appears in the trace buffer.
  4136 
  4137  - Knows about div k and mod k where k is a numeral of type nat or int.
  4138 
  4139  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4140    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4141    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4142 
  4143 * simp's arithmetic capabilities have been enhanced a bit: it now
  4144 takes ~= in premises into account (by performing a case split);
  4145 
  4146 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4147 are distributed over a sum of terms;
  4148 
  4149 * New tactic "trans_tac" and method "trans" instantiate
  4150 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4151 "<=", "<" and "=").
  4152 
  4153 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4154 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4155 
  4156 * 'typedef' command has new option "open" to suppress the set
  4157 definition;
  4158 
  4159 * functions Min and Max on finite sets have been introduced (theory
  4160 Finite_Set);
  4161 
  4162 * attribute [symmetric] now works for relations as well; it turns
  4163 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4164 
  4165 * induct over a !!-quantified statement (say !!x1..xn):
  4166   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4167 
  4168 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4169 %x. None. Warning: empty_def now refers to the previously hidden definition
  4170 of the empty set.
  4171 
  4172 * Algebra: formalization of classical algebra.  Intended as base for
  4173 any algebraic development in Isabelle.  Currently covers group theory
  4174 (up to Sylow's theorem) and ring theory (Universal Property of
  4175 Univariate Polynomials).  Contributions welcome;
  4176 
  4177 * GroupTheory: deleted, since its material has been moved to Algebra;
  4178 
  4179 * Complex: new directory of the complex numbers with numeric constants,
  4180 nonstandard complex numbers, and some complex analysis, standard and
  4181 nonstandard (Jacques Fleuriot);
  4182 
  4183 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4184 
  4185 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4186 Fleuriot);
  4187 
  4188 * Real/HahnBanach: updated and adapted to locales;
  4189 
  4190 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4191 Gray and Kramer);
  4192 
  4193 * UNITY: added the Meier-Sanders theory of progress sets;
  4194 
  4195 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4196 as abstract algorithms, instantiated to the JVM;
  4197 
  4198 * Bali: Java source language formalization. Type system, operational
  4199 semantics, axiomatic semantics. Supported language features:
  4200 classes, interfaces, objects,virtual methods, static methods,
  4201 static/instance fields, arrays, access modifiers, definite
  4202 assignment, exceptions.
  4203 
  4204 
  4205 *** ZF ***
  4206 
  4207 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4208 universe, etc.);
  4209 
  4210 * Main ZF: virtually all theories converted to new-style format;
  4211 
  4212 
  4213 *** ML ***
  4214 
  4215 * Pure: Tactic.prove provides sane interface for internal proofs;
  4216 omits the infamous "standard" operation, so this is more appropriate
  4217 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4218 
  4219 * Pure: improved error reporting of simprocs;
  4220 
  4221 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4222 up simprocs;
  4223 
  4224 
  4225 *** Document preparation ***
  4226 
  4227 * uses \par instead of \\ for line breaks in theory text. This may
  4228 shift some page breaks in large documents. To get the old behaviour
  4229 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4230 
  4231 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4232 other packages
  4233 
  4234 * \<euro> now needs package babel/greek instead of marvosym (which
  4235 broke \Rightarrow)
  4236 
  4237 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4238 textcomp package)
  4239 
  4240 
  4241 
  4242 New in Isabelle2002 (March 2002)
  4243 --------------------------------
  4244 
  4245 *** Document preparation ***
  4246 
  4247 * greatly simplified document preparation setup, including more
  4248 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4249 instructive isatool mkdir; users should basically be able to get
  4250 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4251 users may run a separate document processing stage manually like this:
  4252 "isatool usedir -D output HOL Test && isatool document Test/output";
  4253 
  4254 * theory dependency graph may now be incorporated into documents;
  4255 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4256 with \includegraphics of LaTeX;
  4257 
  4258 * proper spacing of consecutive markup elements, especially text
  4259 blocks after section headings;
  4260 
  4261 * support bold style (for single symbols only), input syntax is like
  4262 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4263 
  4264 * \<bullet> is now output as bold \cdot by default, which looks much
  4265 better in printed text;
  4266 
  4267 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4268 note that these symbols are currently unavailable in Proof General /
  4269 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4270 
  4271 * isatool latex no longer depends on changed TEXINPUTS, instead
  4272 isatool document copies the Isabelle style files to the target
  4273 location;
  4274 
  4275 
  4276 *** Isar ***
  4277 
  4278 * Pure/Provers: improved proof by cases and induction;
  4279   - 'case' command admits impromptu naming of parameters (such as
  4280     "case (Suc n)");
  4281   - 'induct' method divinates rule instantiation from the inductive
  4282     claim; no longer requires excessive ?P bindings for proper
  4283     instantiation of cases;
  4284   - 'induct' method properly enumerates all possibilities of set/type
  4285     rules; as a consequence facts may be also passed through *type*
  4286     rules without further ado;
  4287   - 'induct' method now derives symbolic cases from the *rulified*
  4288     rule (before it used to rulify cases stemming from the internal
  4289     atomized version); this means that the context of a non-atomic
  4290     statement becomes is included in the hypothesis, avoiding the
  4291     slightly cumbersome show "PROP ?case" form;
  4292   - 'induct' may now use elim-style induction rules without chaining
  4293     facts, using ``missing'' premises from the goal state; this allows
  4294     rules stemming from inductive sets to be applied in unstructured
  4295     scripts, while still benefitting from proper handling of non-atomic
  4296     statements; NB: major inductive premises need to be put first, all
  4297     the rest of the goal is passed through the induction;
  4298   - 'induct' proper support for mutual induction involving non-atomic
  4299     rule statements (uses the new concept of simultaneous goals, see
  4300     below);
  4301   - append all possible rule selections, but only use the first
  4302     success (no backtracking);
  4303   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4304   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4305   - added 'print_induct_rules' (covered by help item in recent Proof
  4306     General versions);
  4307   - moved induct/cases attributes to Pure, methods to Provers;
  4308   - generic method setup instantiated for FOL and HOL;
  4309 
  4310 * Pure: support multiple simultaneous goal statements, for example
  4311 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4312 meta-level mechanism, this acts as if several individual goals had
  4313 been stated separately; in particular common proof methods need to be
  4314 repeated in order to cover all claims; note that a single elimination
  4315 step is *not* sufficient to establish the two conjunctions, so this
  4316 fails:
  4317 
  4318   assume "A & B" then have A and B ..   (*".." fails*)
  4319 
  4320 better use "obtain" in situations as above; alternative refer to
  4321 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4322 
  4323 * Pure: proper integration with ``locales''; unlike the original
  4324 version by Florian Kammller, Isar locales package high-level proof
  4325 contexts rather than raw logical ones (e.g. we admit to include
  4326 attributes everywhere); operations on locales include merge and
  4327 rename; support for implicit arguments (``structures''); simultaneous
  4328 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4329 some examples;
  4330 
  4331 * Pure: the following commands have been ``localized'', supporting a
  4332 target locale specification "(in name)": 'lemma', 'theorem',
  4333 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4334 stored both within the locale and at the theory level (exported and
  4335 qualified by the locale name);
  4336 
  4337 * Pure: theory goals may now be specified in ``long'' form, with
  4338 ad-hoc contexts consisting of arbitrary locale elements. for example
  4339 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4340 definitions may be given, too); the result is a meta-level rule with
  4341 the context elements being discharged in the obvious way;
  4342 
  4343 * Pure: new proof command 'using' allows to augment currently used
  4344 facts after a goal statement ('using' is syntactically analogous to
  4345 'apply', but acts on the goal's facts only); this allows chained facts
  4346 to be separated into parts given before and after a claim, as in
  4347 ``from a and b have C using d and e <proof>'';
  4348 
  4349 * Pure: renamed "antecedent" case to "rule_context";
  4350 
  4351 * Pure: new 'judgment' command records explicit information about the
  4352 object-logic embedding (used by several tools internally); no longer
  4353 use hard-wired "Trueprop";
  4354 
  4355 * Pure: added 'corollary' command;
  4356 
  4357 * Pure: fixed 'token_translation' command;
  4358 
  4359 * Pure: removed obsolete 'exported' attribute;
  4360 
  4361 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4362 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4363 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4364 
  4365 * Pure: method 'atomize' presents local goal premises as object-level
  4366 statements (atomic meta-level propositions); setup controlled via
  4367 rewrite rules declarations of 'atomize' attribute; example
  4368 application: 'induct' method with proper rule statements in improper
  4369 proof *scripts*;
  4370 
  4371 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4372 now consider the syntactic context of assumptions, giving a better
  4373 chance to get type-inference of the arguments right (this is
  4374 especially important for locales);
  4375 
  4376 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4377 mode;
  4378 
  4379 * Pure/obtain: the formal conclusion "thesis", being marked as
  4380 ``internal'', may no longer be reference directly in the text;
  4381 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4382 situations;
  4383 
  4384 * Pure: generic 'sym' attribute which declares a rule both as pure
  4385 'elim?' and for the 'symmetric' operation;
  4386 
  4387 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4388 text; the fixed correlation with particular command syntax has been
  4389 discontinued;
  4390 
  4391 * Pure: new method 'rules' is particularly well-suited for proof
  4392 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4393 but often produces more compact proof terms with less detours;
  4394 
  4395 * Pure/Provers/classical: simplified integration with pure rule
  4396 attributes and methods; the classical "intro?/elim?/dest?"
  4397 declarations coincide with the pure ones; the "rule" method no longer
  4398 includes classically swapped intros; "intro" and "elim" methods no
  4399 longer pick rules from the context; also got rid of ML declarations
  4400 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4401 INCOMPATIBILITY;
  4402 
  4403 * Provers/classical: attribute 'swapped' produces classical inversions
  4404 of introduction rules;
  4405 
  4406 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4407 rules instead of full simplifier context; 'iff' attribute handles
  4408 conditional rules;
  4409 
  4410 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4411 
  4412 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4413 "(permissive)" option to recover old behavior;
  4414 
  4415 * HOL: 'inductive' no longer features separate (collective) attributes
  4416 for 'intros' (was found too confusing);
  4417 
  4418 * HOL: properly declared induction rules less_induct and
  4419 wf_induct_rule;
  4420 
  4421 
  4422 *** HOL ***
  4423 
  4424 * HOL: moved over to sane numeral syntax; the new policy is as
  4425 follows:
  4426 
  4427   - 0 and 1 are polymorphic constants, which are defined on any
  4428   numeric type (nat, int, real etc.);
  4429 
  4430   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4431   binary representation internally;
  4432 
  4433   - type nat has special constructor Suc, and generally prefers Suc 0
  4434   over 1::nat and Suc (Suc 0) over 2::nat;
  4435 
  4436 This change may cause significant problems of INCOMPATIBILITY; here
  4437 are some hints on converting existing sources:
  4438 
  4439   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4440   entities, so expressions involving "-" (unary or binary minus) need
  4441   to be spaced properly;
  4442 
  4443   - existing occurrences of "1" may need to be constraint "1::nat" or
  4444   even replaced by Suc 0; similar for old "2";
  4445 
  4446   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4447 
  4448   - remove all special provisions on numerals in proofs;
  4449 
  4450 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4451 representation (depends on bin_arith_simps in the default context);
  4452 
  4453 * HOL: symbolic syntax for x^2 (numeral 2);
  4454 
  4455 * HOL: the class of all HOL types is now called "type" rather than
  4456 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4457 in axclass/classes, instance/arities, and (usually rare) occurrences
  4458 in typings (of consts etc.); internally the class is called
  4459 "HOL.type", ML programs should refer to HOLogic.typeS;
  4460 
  4461 * HOL/record package improvements:
  4462   - new derived operations "fields" to build a partial record section,
  4463     "extend" to promote a fixed record to a record scheme, and
  4464     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4465     declared as simp by default;
  4466   - shared operations ("more", "fields", etc.) now need to be always
  4467     qualified) --- potential INCOMPATIBILITY;
  4468   - removed "make_scheme" operations (use "make" with "extend") --
  4469     INCOMPATIBILITY;
  4470   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4471   - provides cases/induct rules for use with corresponding Isar
  4472     methods (for concrete records, record schemes, concrete more
  4473     parts, and schematic more parts -- in that order);
  4474   - internal definitions directly based on a light-weight abstract
  4475     theory of product types over typedef rather than datatype;
  4476 
  4477 * HOL: generic code generator for generating executable ML code from
  4478 specifications; specific support for HOL constructs such as inductive
  4479 datatypes and sets, as well as recursive functions; can be invoked
  4480 via 'generate_code' theory section;
  4481 
  4482 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4483 
  4484 * HOL: consolidated and renamed several theories.  In particular:
  4485         Ord.thy has been absorbed into HOL.thy
  4486         String.thy has been absorbed into List.thy
  4487 
  4488 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4489 (beware of argument permutation!);
  4490 
  4491 * HOL: linorder_less_split superseded by linorder_cases;
  4492 
  4493 * HOL/List: "nodups" renamed to "distinct";
  4494 
  4495 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4496 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4497   - Ex_def has changed, now need to use some_eq_ex
  4498 
  4499 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4500 in this (rare) case use:
  4501 
  4502   delSWrapper "split_all_tac"
  4503   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4504 
  4505 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4506 MAY FAIL;
  4507 
  4508 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4509 Isabelle's type classes, ^ on functions and relations has too general
  4510 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4511 necessary to attach explicit type constraints;
  4512 
  4513 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4514 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4515 renamed accordingly (eg "compI" -> "rel_compI").
  4516 
  4517 * HOL: syntax translations now work properly with numerals and records
  4518 expressions;
  4519 
  4520 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4521 of "lam" -- INCOMPATIBILITY;
  4522 
  4523 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4524 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4525 renamed "Product_Type.unit";
  4526 
  4527 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4528 
  4529 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4530 the "cases" method);
  4531 
  4532 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4533 Florian Kammller);
  4534 
  4535 * HOL/IMP: updated and converted to new-style theory format; several
  4536 parts turned into readable document, with proper Isar proof texts and
  4537 some explanations (by Gerwin Klein);
  4538 
  4539 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4540 
  4541 * HOL-Hyperreal is now a logic image;
  4542 
  4543 
  4544 *** HOLCF ***
  4545 
  4546 * Isar: consts/constdefs supports mixfix syntax for continuous
  4547 operations;
  4548 
  4549 * Isar: domain package adapted to new-style theory format, e.g. see
  4550 HOLCF/ex/Dnat.thy;
  4551 
  4552 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4553 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4554 lift.induct_tac, always use UU instead of Undef;
  4555 
  4556 * HOLCF/IMP: updated and converted to new-style theory;
  4557 
  4558 
  4559 *** ZF ***
  4560 
  4561 * Isar: proper integration of logic-specific tools and packages,
  4562 including theory commands '(co)inductive', '(co)datatype',
  4563 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4564 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4565 
  4566 * theory Main no longer includes AC; for the Axiom of Choice, base
  4567 your theory on Main_ZFC;
  4568 
  4569 * the integer library now covers quotients and remainders, with many
  4570 laws relating division to addition, multiplication, etc.;
  4571 
  4572 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4573 typeless version of the formalism;
  4574 
  4575 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4576 format;
  4577 
  4578 * ZF/Induct: new directory for examples of inductive definitions,
  4579 including theory Multiset for multiset orderings; converted to
  4580 new-style theory format;
  4581 
  4582 * ZF: many new theorems about lists, ordinals, etc.;
  4583 
  4584 
  4585 *** General ***
  4586 
  4587 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4588 variable proof controls level of detail: 0 = no proofs (only oracle
  4589 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4590 also ref manual for further ML interfaces;
  4591 
  4592 * Pure/axclass: removed obsolete ML interface
  4593 goal_subclass/goal_arity;
  4594 
  4595 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4596 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4597 separate tokens, so expressions involving minus need to be spaced
  4598 properly;
  4599 
  4600 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4601 rather than "infixl" or "infixr";
  4602 
  4603 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4604 sort constraint specifications in type inference; e.g. "x::_::foo"
  4605 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4606 type variable);
  4607 
  4608 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4609 control output of nested => (types); the default behavior is
  4610 "type_brackets";
  4611 
  4612 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4613 tokens into AST constants;
  4614 
  4615 * Pure/syntax: prefer later declarations of translations and print
  4616 translation functions; potential INCOMPATIBILITY: need to reverse
  4617 multiple declarations for same syntax element constant;
  4618 
  4619 * Pure/show_hyps reset by default (in accordance to existing Isar
  4620 practice);
  4621 
  4622 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4623 addSafter;
  4624 
  4625 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4626 as well;
  4627 
  4628 * system: tested support for MacOS X; should be able to get Isabelle +
  4629 Proof General to work in a plain Terminal after installing Poly/ML
  4630 (e.g. from the Isabelle distribution area) and GNU bash alone
  4631 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4632 support requires further installations, e.g. from
  4633 http://fink.sourceforge.net/);
  4634 
  4635 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4636 
  4637 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4638 of 40 MB), cf. ML_OPTIONS;
  4639 
  4640 * system: Proof General keywords specification is now part of the
  4641 Isabelle distribution (see etc/isar-keywords.el);
  4642 
  4643 * system: support for persistent Proof General sessions (refrain from
  4644 outdating all loaded theories on startup); user may create writable
  4645 logic images like this: ``isabelle -q HOL Test'';
  4646 
  4647 * system: smart selection of Isabelle process versus Isabelle
  4648 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4649 run both "isabelle" and "Isabelle" even if file names are badly
  4650 damaged (executable inspects the case of the first letter of its own
  4651 name); added separate "isabelle-process" and "isabelle-interface";
  4652 
  4653 * system: refrain from any attempt at filtering input streams; no
  4654 longer support ``8bit'' encoding of old isabelle font, instead proper
  4655 iso-latin characters may now be used; the related isatools
  4656 "symbolinput" and "nonascii" have disappeared as well;
  4657 
  4658 * system: removed old "xterm" interface (the print modes "xterm" and
  4659 "xterm_color" are still available for direct use in a suitable
  4660 terminal);
  4661 
  4662 
  4663 
  4664 New in Isabelle99-2 (February 2001)
  4665 -----------------------------------
  4666 
  4667 *** Overview of INCOMPATIBILITIES ***
  4668 
  4669 * HOL: please note that theories in the Library and elsewhere often use the
  4670 new-style (Isar) format; to refer to their theorems in an ML script you must
  4671 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4672 
  4673 * HOL: inductive package no longer splits induction rule aggressively,
  4674 but only as far as specified by the introductions given; the old
  4675 format may be recovered via ML function complete_split_rule or attribute
  4676 'split_rule (complete)';
  4677 
  4678 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4679 gfp_Tarski to gfp_unfold;
  4680 
  4681 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4682 
  4683 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4684 relation); infix "^^" has been renamed "``"; infix "``" has been
  4685 renamed "`"; "univalent" has been renamed "single_valued";
  4686 
  4687 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4688 operation;
  4689 
  4690 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4691 
  4692 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4693 
  4694 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4695 consequence, it is no longer monotonic wrt. the local goal context
  4696 (which is now passed through the inductive cases);
  4697 
  4698 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4699 \<gg> to \<ggreater>;
  4700 
  4701 
  4702 *** Document preparation ***
  4703 
  4704 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4705 available: are "it" for near math-mode best-style output, "sl" for
  4706 slanted text style, and "tt" for plain type-writer; if no
  4707 \isabellestyle command is given, output is according to slanted
  4708 type-writer);
  4709 
  4710 * support sub/super scripts (for single symbols only), input syntax is
  4711 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4712 
  4713 * some more standard symbols; see Appendix A of the system manual for
  4714 the complete list of symbols defined in isabellesym.sty;
  4715 
  4716 * improved isabelle style files; more abstract symbol implementation
  4717 (should now use \isamath{...} and \isatext{...} in custom symbol
  4718 definitions);
  4719 
  4720 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4721 state; Note that presentation of goal states does not conform to
  4722 actual human-readable proof documents.  Please do not include goal
  4723 states into document output unless you really know what you are doing!
  4724 
  4725 * proper indentation of antiquoted output with proportional LaTeX
  4726 fonts;
  4727 
  4728 * no_document ML operator temporarily disables LaTeX document
  4729 generation;
  4730 
  4731 * isatool unsymbolize tunes sources for plain ASCII communication;
  4732 
  4733 
  4734 *** Isar ***
  4735 
  4736 * Pure: Isar now suffers initial goal statements to contain unbound
  4737 schematic variables (this does not conform to actual readable proof
  4738 documents, due to unpredictable outcome and non-compositional proof
  4739 checking); users who know what they are doing may use schematic goals
  4740 for Prolog-style synthesis of proven results;
  4741 
  4742 * Pure: assumption method (an implicit finishing) now handles actual
  4743 rules as well;
  4744 
  4745 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4746 initial goal, declare "that" only as Pure intro (only for single
  4747 steps); the "that" rule assumption may now be involved in implicit
  4748 finishing, thus ".." becomes a feasible for trivial obtains;
  4749 
  4750 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4751 instance proofs may be performed by "..";
  4752 
  4753 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4754 statements as well;
  4755 
  4756 * Pure: more robust selection of calculational rules;
  4757 
  4758 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4759 rule (as well as the assumption rule);
  4760 
  4761 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4762 lemmas, using the graph browser tool;
  4763 
  4764 * Pure: predict failure of "show" in interactive mode;
  4765 
  4766 * Pure: 'thms_containing' now takes actual terms as arguments;
  4767 
  4768 * HOL: improved method 'induct' --- now handles non-atomic goals
  4769 (potential INCOMPATIBILITY); tuned error handling;
  4770 
  4771 * HOL: cases and induct rules now provide explicit hints about the
  4772 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4773 any remaining facts are inserted into the goal verbatim;
  4774 
  4775 * HOL: local contexts (aka cases) may now contain term bindings as
  4776 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4777 the result to be shown in each case;
  4778 
  4779 * HOL: added 'recdef_tc' command;
  4780 
  4781 * isatool convert assists in eliminating legacy ML scripts;
  4782 
  4783 
  4784 *** HOL ***
  4785 
  4786 * HOL/Library: a collection of generic theories to be used together
  4787 with main HOL; the theory loader path already includes this directory
  4788 by default; the following existing theories have been moved here:
  4789 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4790 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4791 
  4792 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4793 modelling and verification task performed in Isabelle/HOL +
  4794 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4795 
  4796 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4797 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4798 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4799 'domain', this makes the theory consistent with mathematical
  4800 literature;
  4801 
  4802 * HOL basics: added overloaded operations "inverse" and "divide"
  4803 (infix "/"), syntax for generic "abs" operation, generic summation
  4804 operator \<Sum>;
  4805 
  4806 * HOL/typedef: simplified package, provide more useful rules (see also
  4807 HOL/subset.thy);
  4808 
  4809 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4810 now expressed as a proper nested rule (old-style tactic scripts may
  4811 require atomize_strip_tac to cope with non-atomic premises);
  4812 
  4813 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4814 to "split_conv" (old name still available for compatibility);
  4815 
  4816 * HOL: improved concrete syntax for strings (e.g. allows translation
  4817 rules with string literals);
  4818 
  4819 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4820  and Fleuriot's mechanization of analysis, including the transcendental
  4821  functions for the reals;
  4822 
  4823 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4824 
  4825 
  4826 *** CTT ***
  4827 
  4828 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4829 "lam" is displayed as TWO lambda-symbols
  4830 
  4831 * CTT: theory Main now available, containing everything (that is, Bool
  4832 and Arith);
  4833 
  4834 
  4835 *** General ***
  4836 
  4837 * Pure: the Simplifier has been implemented properly as a derived rule
  4838 outside of the actual kernel (at last!); the overall performance
  4839 penalty in practical applications is about 50%, while reliability of
  4840 the Isabelle inference kernel has been greatly improved;
  4841 
  4842 * print modes "brackets" and "no_brackets" control output of nested =>
  4843 (types) and ==> (props); the default behaviour is "brackets";
  4844 
  4845 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4846 as assumptions as well;
  4847 
  4848 * system: support Poly/ML 4.0;
  4849 
  4850 * system: isatool install handles KDE version 1 or 2;
  4851 
  4852 
  4853 
  4854 New in Isabelle99-1 (October 2000)
  4855 ----------------------------------
  4856 
  4857 *** Overview of INCOMPATIBILITIES ***
  4858 
  4859 * HOL: simplification of natural numbers is much changed; to partly
  4860 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4861 issue the following ML commands:
  4862 
  4863   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4864   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4865 
  4866 * HOL: simplification no longer dives into case-expressions; this is
  4867 controlled by "t.weak_case_cong" for each datatype t;
  4868 
  4869 * HOL: nat_less_induct renamed to less_induct;
  4870 
  4871 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4872 fixsome to patch .thy and .ML sources automatically;
  4873 
  4874   select_equality  -> some_equality
  4875   select_eq_Ex     -> some_eq_ex
  4876   selectI2EX       -> someI2_ex
  4877   selectI2         -> someI2
  4878   selectI          -> someI
  4879   select1_equality -> some1_equality
  4880   Eps_sym_eq       -> some_sym_eq_trivial
  4881   Eps_eq           -> some_eq_trivial
  4882 
  4883 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4884 
  4885 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4886 instead);
  4887 
  4888 * HOL: the recursion equations generated by 'recdef' are now called
  4889 f.simps instead of f.rules;
  4890 
  4891 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4892 
  4893 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4894 sometimes be needed;
  4895 
  4896 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4897 
  4898 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4899 
  4900 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4901 product is now "<*>" instead of "Times"; the lexicographic product is
  4902 now "<*lex*>" instead of "**";
  4903 
  4904 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4905 of main HOL, but was unused); better use HOL's datatype package;
  4906 
  4907 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4908 the old syntax may be recovered as follows:
  4909 
  4910   syntax (symbols)
  4911     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4912       (infixl "\\<oplus>" 100)
  4913 
  4914 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4915 
  4916 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4917 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4918 internally;
  4919 
  4920 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4921 changed from A/r to A//r;
  4922 
  4923 * ZF: new treatment of arithmetic (nat & int) may break some old
  4924 proofs;
  4925 
  4926 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4927 rulify -> rule_format, elimify -> elim_format, ...);
  4928 
  4929 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4930 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4931 should have to change intro!! to intro? only); replaced "delrule" by
  4932 "rule del";
  4933 
  4934 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4935 
  4936 * Provers: strengthened force_tac by using new first_best_tac;
  4937 
  4938 * LaTeX document preparation: several changes of isabelle.sty (see
  4939 lib/texinputs);
  4940 
  4941 
  4942 *** Document preparation ***
  4943 
  4944 * formal comments (text blocks etc.) in new-style theories may now
  4945 contain antiquotations of thm/prop/term/typ/text to be presented
  4946 according to latex print mode; concrete syntax is like this:
  4947 @{term[show_types] "f(x) = a + x"};
  4948 
  4949 * isatool mkdir provides easy setup of Isabelle session directories,
  4950 including proper document sources;
  4951 
  4952 * generated LaTeX sources are now deleted after successful run
  4953 (isatool document -c); may retain a copy somewhere else via -D option
  4954 of isatool usedir;
  4955 
  4956 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4957 style files, achieving self-contained LaTeX sources and simplifying
  4958 LaTeX debugging;
  4959 
  4960 * old-style theories now produce (crude) LaTeX output as well;
  4961 
  4962 * browser info session directories are now self-contained (may be put
  4963 on WWW server seperately); improved graphs of nested sessions; removed
  4964 graph for 'all sessions';
  4965 
  4966 * several improvements in isabelle style files; \isabellestyle{it}
  4967 produces fake math mode output; \isamarkupheader is now \section by
  4968 default; see lib/texinputs/isabelle.sty etc.;
  4969 
  4970 
  4971 *** Isar ***
  4972 
  4973 * Isar/Pure: local results and corresponding term bindings are now
  4974 subject to Hindley-Milner polymorphism (similar to ML); this
  4975 accommodates incremental type-inference very nicely;
  4976 
  4977 * Isar/Pure: new derived language element 'obtain' supports
  4978 generalized existence reasoning;
  4979 
  4980 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4981 support accumulation of results, without applying any rules yet;
  4982 useful to collect intermediate results without explicit name
  4983 references, and for use with transitivity rules with more than 2
  4984 premises;
  4985 
  4986 * Isar/Pure: scalable support for case-analysis type proofs: new
  4987 'case' language element refers to local contexts symbolically, as
  4988 produced by certain proof methods; internally, case names are attached
  4989 to theorems as "tags";
  4990 
  4991 * Isar/Pure: theory command 'hide' removes declarations from
  4992 class/type/const name spaces;
  4993 
  4994 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4995 indicate potential overloading;
  4996 
  4997 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4998 
  4999 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5000 "{a,b,c}" instead of {a,b,c};
  5001 
  5002 * Isar/Pure now provides its own version of intro/elim/dest
  5003 attributes; useful for building new logics, but beware of confusion
  5004 with the version in Provers/classical;
  5005 
  5006 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5007 case name 'antecedent';
  5008 
  5009 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5010 to the current context is now done automatically);
  5011 
  5012 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5013 for definining proof methods in ML;
  5014 
  5015 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5016 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5017 most cases, one should have to change intro!! to intro? only);
  5018 replaced "delrule" by "rule del";
  5019 
  5020 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5021 'symmetric' attribute (the latter supercedes [RS sym]);
  5022 
  5023 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5024 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5025 well (including splits);
  5026 
  5027 * Isar/Provers: Simplifier and Classical methods now support all kind
  5028 of modifiers used in the past, including 'cong', 'iff', etc.
  5029 
  5030 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5031 of Simplifier and Classical reasoner);
  5032 
  5033 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5034 now support named cases; major packages (inductive, datatype, primrec,
  5035 recdef) support case names and properly name parameters;
  5036 
  5037 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5038 monotonicity conditions are extracted to be proven at end of
  5039 calculations;
  5040 
  5041 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5042 method anyway;
  5043 
  5044 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5045 split_if split_if_asm; datatype package provides theorems foo.splits =
  5046 foo.split foo.split_asm for each datatype;
  5047 
  5048 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5049 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5050 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5051 use "(cases (simplified))" method in proper proof texts);
  5052 
  5053 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5054 
  5055 * Isar: names of theorems etc. may be natural numbers as well;
  5056 
  5057 * Isar: 'pr' command: optional arguments for goals_limit and
  5058 ProofContext.prems_limit; no longer prints theory contexts, but only
  5059 proof states;
  5060 
  5061 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5062 additional print modes to be specified; e.g. "pr(latex)" will print
  5063 proof state according to the Isabelle LaTeX style;
  5064 
  5065 * Isar: improved support for emulating tactic scripts, including proof
  5066 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5067 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5068 (for HOL datatypes);
  5069 
  5070 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5071 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5072 'proof method scripts' have to be in depth-first order;
  5073 
  5074 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5075 
  5076 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5077 should instead use individual commands for printing items
  5078 (print_commands, print_methods etc.);
  5079 
  5080 * Isar: added 'nothing' --- the empty list of theorems;
  5081 
  5082 
  5083 *** HOL ***
  5084 
  5085 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5086 corresponding virtual machine and a specification of its bytecode
  5087 verifier and a lightweight bytecode verifier, including proofs of
  5088 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5089 Cornelia Pusch (see also the homepage of project Bali at
  5090 http://isabelle.in.tum.de/Bali/);
  5091 
  5092 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5093 Clemens Ballarin;
  5094 
  5095 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5096 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5097 Rasmussen;
  5098 
  5099 * HOL/Lattice: fundamental concepts of lattice theory and order
  5100 structures, including duals, properties of bounds versus algebraic
  5101 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5102 Theorem for complete lattices etc.; may also serve as a demonstration
  5103 for abstract algebraic reasoning using axiomatic type classes, and
  5104 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5105 
  5106 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5107 von Oheimb;
  5108 
  5109 * HOL/IMPP: extension of IMP with local variables and mutually
  5110 recursive procedures, by David von Oheimb;
  5111 
  5112 * HOL/Lambda: converted into new-style theory and document;
  5113 
  5114 * HOL/ex/Multiquote: example of multiple nested quotations and
  5115 anti-quotations -- basically a generalized version of de-Bruijn
  5116 representation; very useful in avoiding lifting of operations;
  5117 
  5118 * HOL/record: added general record equality rule to simpset; fixed
  5119 select-update simplification procedure to handle extended records as
  5120 well; admit "r" as field name;
  5121 
  5122 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5123 other numeric types and also as the identity of groups, rings, etc.;
  5124 
  5125 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5126 Types nat and int belong to this axclass;
  5127 
  5128 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5129    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5130    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5131   two terms #m*u and #n*u are replaced by #(m+n)*u
  5132     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5133   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5134     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5135 
  5136 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5137 powerful prover for predicate logic but knows nothing of clasets; see
  5138 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5139 
  5140 * HOL: new version of "case_tac" subsumes both boolean case split and
  5141 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5142 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5143 
  5144 * HOL: simplification no longer dives into case-expressions: only the
  5145 selector expression is simplified, but not the remaining arms; to
  5146 enable full simplification of case-expressions for datatype t, you may
  5147 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5148 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5149 
  5150 * HOL/recdef: the recursion equations generated by 'recdef' for
  5151 function 'f' are now called f.simps instead of f.rules; if all
  5152 termination conditions are proved automatically, these simplification
  5153 rules are added to the simpset, as in primrec; rules may be named
  5154 individually as well, resulting in a separate list of theorems for
  5155 each equation;
  5156 
  5157 * HOL/While is a new theory that provides a while-combinator. It
  5158 permits the definition of tail-recursive functions without the
  5159 provision of a termination measure. The latter is necessary once the
  5160 invariant proof rule for while is applied.
  5161 
  5162 * HOL: new (overloaded) notation for the set of elements below/above
  5163 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5164 
  5165 * HOL: theorems impI, allI, ballI bound as "strip";
  5166 
  5167 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5168 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5169 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5170 
  5171 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5172 
  5173 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5174 main HOL, but was unused);
  5175 
  5176 * HOL: fewer consts declared as global (e.g. have to refer to
  5177 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5178 
  5179 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5180 in case of overlap with user translations (e.g. judgements over
  5181 tuples); (note that the underlying logical represenation is still
  5182 bogus);
  5183 
  5184 
  5185 *** ZF ***
  5186 
  5187 * ZF: simplification automatically cancels common terms in arithmetic
  5188 expressions over nat and int;
  5189 
  5190 * ZF: new treatment of nat to minimize type-checking: all operators
  5191 coerce their operands to a natural number using the function natify,
  5192 making the algebraic laws unconditional;
  5193 
  5194 * ZF: as above, for int: operators coerce their operands to an integer
  5195 using the function intify;
  5196 
  5197 * ZF: the integer library now contains many of the usual laws for the
  5198 orderings, including $<=, and monotonicity laws for $+ and $*;
  5199 
  5200 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5201 simplification;
  5202 
  5203 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5204 to the simplifier and classical reasoner simultaneously;
  5205 
  5206 
  5207 *** General ***
  5208 
  5209 * Provers: blast_tac now handles actual object-logic rules as
  5210 assumptions; note that auto_tac uses blast_tac internally as well;
  5211 
  5212 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5213 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5214 
  5215 * Provers: delrules now handles destruct rules as well (no longer need
  5216 explicit make_elim);
  5217 
  5218 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5219   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5220 use instead the strong form,
  5221   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5222 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5223 from destruct-rules;
  5224 
  5225 * Provers: Simplifier.easy_setup provides a fast path to basic
  5226 Simplifier setup for new object-logics;
  5227 
  5228 * Pure: AST translation rules no longer require constant head on LHS;
  5229 
  5230 * Pure: improved name spaces: ambiguous output is qualified; support
  5231 for hiding of names;
  5232 
  5233 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5234 XSYMBOL_HOME; no longer need to do manual configuration in most
  5235 situations;
  5236 
  5237 * system: compression of ML heaps images may now be controlled via -c
  5238 option of isabelle and isatool usedir (currently only observed by
  5239 Poly/ML);
  5240 
  5241 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5242 useful for remote X11);
  5243 
  5244 * system: provide TAGS file for Isabelle sources;
  5245 
  5246 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5247 order;
  5248 
  5249 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5250 timing flag supersedes proof_timing and Toplevel.trace;
  5251 
  5252 * ML: new combinators |>> and |>>> for incremental transformations
  5253 with secondary results (e.g. certain theory extensions):
  5254 
  5255 * ML: PureThy.add_defs gets additional argument to indicate potential
  5256 overloading (usually false);
  5257 
  5258 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5259 results;
  5260 
  5261 
  5262 
  5263 New in Isabelle99 (October 1999)
  5264 --------------------------------
  5265 
  5266 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5267 
  5268 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5269 are no longer simplified.  (This allows the simplifier to unfold recursive
  5270 functional programs.)  To restore the old behaviour, declare
  5271 
  5272     Delcongs [if_weak_cong];
  5273 
  5274 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5275 complement;
  5276 
  5277 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5278 
  5279 * HOL/datatype: mutual_induct_tac no longer exists --
  5280   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5281 
  5282 * HOL/typedef: fixed type inference for representing set; type
  5283 arguments now have to occur explicitly on the rhs as type constraints;
  5284 
  5285 * ZF: The con_defs part of an inductive definition may no longer refer
  5286 to constants declared in the same theory;
  5287 
  5288 * HOL, ZF: the function mk_cases, generated by the inductive
  5289 definition package, has lost an argument.  To simplify its result, it
  5290 uses the default simpset instead of a supplied list of theorems.
  5291 
  5292 * HOL/List: the constructors of type list are now Nil and Cons;
  5293 
  5294 * Simplifier: the type of the infix ML functions
  5295         setSSolver addSSolver setSolver addSolver
  5296 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5297 for packaging solvers. A solver is created via
  5298         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5299 where the string argument is only a comment.
  5300 
  5301 
  5302 *** Proof tools ***
  5303 
  5304 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5305 decision procedure for linear arithmetic. Currently it is used for
  5306 types `nat', `int', and `real' in HOL (see below); it can, should and
  5307 will be instantiated for other types and logics as well.
  5308 
  5309 * The simplifier now accepts rewrite rules with flexible heads, eg
  5310      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5311   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5312   matching.
  5313 
  5314 
  5315 *** General ***
  5316 
  5317 * New Isabelle/Isar subsystem provides an alternative to traditional
  5318 tactical theorem proving; together with the ProofGeneral/isar user
  5319 interface it offers an interactive environment for developing human
  5320 readable proof documents (Isar == Intelligible semi-automated
  5321 reasoning); for further information see isatool doc isar-ref,
  5322 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5323 
  5324 * improved and simplified presentation of theories: better HTML markup
  5325 (including colors), graph views in several sizes; isatool usedir now
  5326 provides a proper interface for user theories (via -P option); actual
  5327 document preparation based on (PDF)LaTeX is available as well (for
  5328 new-style theories only); see isatool doc system for more information;
  5329 
  5330 * native support for Proof General, both for classic Isabelle and
  5331 Isabelle/Isar;
  5332 
  5333 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5334 using the graph browser tool;
  5335 
  5336 * Isabelle manuals now also available as PDF;
  5337 
  5338 * theory loader rewritten from scratch (may not be fully
  5339 bug-compatible); old loadpath variable has been replaced by show_path,
  5340 add_path, del_path, reset_path functions; new operations such as
  5341 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5342 isatool doc ref);
  5343 
  5344 * improved isatool install: option -k creates KDE application icon,
  5345 option -p DIR installs standalone binaries;
  5346 
  5347 * added ML_PLATFORM setting (useful for cross-platform installations);
  5348 more robust handling of platform specific ML images for SML/NJ;
  5349 
  5350 * the settings environment is now statically scoped, i.e. it is never
  5351 created again in sub-processes invoked from isabelle, isatool, or
  5352 Isabelle;
  5353 
  5354 * path element specification '~~' refers to '$ISABELLE_HOME';
  5355 
  5356 * in locales, the "assumes" and "defines" parts may be omitted if
  5357 empty;
  5358 
  5359 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5360 long arrows);
  5361 
  5362 * new print_mode "HTML";
  5363 
  5364 * new flag show_tags controls display of tags of theorems (which are
  5365 basically just comments that may be attached by some tools);
  5366 
  5367 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5368 mode and goal output format:
  5369 
  5370 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5371 244c244
  5372 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5373 ---
  5374 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5375 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5376 181c181
  5377 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5378 ---
  5379 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5380 
  5381 * function bind_thms stores lists of theorems (cf. bind_thm);
  5382 
  5383 * new shorthand tactics ftac, eatac, datac, fatac;
  5384 
  5385 * qed (and friends) now accept "" as result name; in that case the
  5386 theorem is not stored, but proper checks and presentation of the
  5387 result still apply;
  5388 
  5389 * theorem database now also indexes constants "Trueprop", "all",
  5390 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5391 
  5392 
  5393 *** HOL ***
  5394 
  5395 ** HOL arithmetic **
  5396 
  5397 * There are now decision procedures for linear arithmetic over nat and
  5398 int:
  5399 
  5400 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5401 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5402 are treated as atomic; subformulae not involving type `nat' or `int'
  5403 are ignored; quantified subformulae are ignored unless they are
  5404 positive universal or negative existential. The tactic has to be
  5405 invoked by hand and can be a little bit slow. In particular, the
  5406 running time is exponential in the number of occurrences of `min' and
  5407 `max', and `-' on `nat'.
  5408 
  5409 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5410 (negated) (in)equalities among the premises and the conclusion into
  5411 account (i.e. no compound formulae) and does not know about `min' and
  5412 `max', and `-' on `nat'. It is fast and is used automatically by the
  5413 simplifier.
  5414 
  5415 NB: At the moment, these decision procedures do not cope with mixed
  5416 nat/int formulae where the two parts interact, such as `m < n ==>
  5417 int(m) < int(n)'.
  5418 
  5419 * HOL/Numeral provides a generic theory of numerals (encoded
  5420 efficiently as bit strings); setup for types nat/int/real is in place;
  5421 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5422 int, existing theories and proof scripts may require a few additional
  5423 type constraints;
  5424 
  5425 * integer division and remainder can now be performed on constant
  5426 arguments;
  5427 
  5428 * many properties of integer multiplication, division and remainder
  5429 are now available;
  5430 
  5431 * An interface to the Stanford Validity Checker (SVC) is available through the
  5432 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5433 are proved automatically.  SVC must be installed separately, and its results
  5434 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5435 invocation of the underlying oracle).  For SVC see
  5436   http://verify.stanford.edu/SVC
  5437 
  5438 * IsaMakefile: the HOL-Real target now builds an actual image;
  5439 
  5440 
  5441 ** HOL misc **
  5442 
  5443 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5444 (in Isabelle/Isar) -- by Gertrud Bauer;
  5445 
  5446 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5447 analysis for assembly languages with subtypes;
  5448 
  5449 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5450 -- avoids syntactic ambiguities and treats state, transition, and
  5451 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5452 changed syntax and (many) tactics;
  5453 
  5454 * HOL/inductive: Now also handles more general introduction rules such
  5455   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5456   theorems are now maintained within the theory (maintained via the
  5457   "mono" attribute);
  5458 
  5459 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5460   (using function types) such as
  5461 
  5462   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5463 
  5464 * HOL/record: record_simproc (part of the default simpset) takes care
  5465 of selectors applied to updated records; record_split_tac is no longer
  5466 part of the default claset; update_defs may now be removed from the
  5467 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5468 
  5469   claset_ref () := claset() addSWrapper record_split_wrapper;
  5470   Delsimprocs [record_simproc]
  5471 
  5472 * HOL/typedef: fixed type inference for representing set; type
  5473 arguments now have to occur explicitly on the rhs as type constraints;
  5474 
  5475 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5476 names rather than an ML expression;
  5477 
  5478 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5479 supplied later.  Program schemes can be defined, such as
  5480     "While B C s = (if B s then While B C (C s) else s)"
  5481 where the well-founded relation can be chosen after B and C have been given.
  5482 
  5483 * HOL/List: the constructors of type list are now Nil and Cons;
  5484 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5485 course, ML tools referring to List.list.op # etc. have to be adapted;
  5486 
  5487 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5488 disabled by default; run isabelle with option -m HOL to get back to
  5489 the original Gordon/HOL-style output;
  5490 
  5491 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5492 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5493 
  5494 * HOL basic syntax simplified (more orthogonal): all variants of
  5495 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5496 Eps operator is provided as well: "SOME x. P[x]";
  5497 
  5498 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5499 
  5500 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5501 thus available for user theories;
  5502 
  5503 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5504 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5505 time;
  5506 
  5507 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5508 several times and then mp;
  5509 
  5510 
  5511 *** LK ***
  5512 
  5513 * the notation <<...>> is now available as a notation for sequences of
  5514 formulas;
  5515 
  5516 * the simplifier is now installed
  5517 
  5518 * the axiom system has been generalized (thanks to Soren Heilmann)
  5519 
  5520 * the classical reasoner now has a default rule database
  5521 
  5522 
  5523 *** ZF ***
  5524 
  5525 * new primrec section allows primitive recursive functions to be given
  5526 directly (as in HOL) over datatypes and the natural numbers;
  5527 
  5528 * new tactics induct_tac and exhaust_tac for induction (or case
  5529 analysis) over datatypes and the natural numbers;
  5530 
  5531 * the datatype declaration of type T now defines the recursor T_rec;
  5532 
  5533 * simplification automatically does freeness reasoning for datatype
  5534 constructors;
  5535 
  5536 * automatic type-inference, with AddTCs command to insert new
  5537 type-checking rules;
  5538 
  5539 * datatype introduction rules are now added as Safe Introduction rules
  5540 to the claset;
  5541 
  5542 * the syntax "if P then x else y" is now available in addition to
  5543 if(P,x,y);
  5544 
  5545 
  5546 *** Internal programming interfaces ***
  5547 
  5548 * tuned simplifier trace output; new flag debug_simp;
  5549 
  5550 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5551 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5552 
  5553 * AxClass.axclass_tac lost the theory argument;
  5554 
  5555 * tuned current_goals_markers semantics: begin / end goal avoids
  5556 printing empty lines;
  5557 
  5558 * removed prs and prs_fn hook, which was broken because it did not
  5559 include \n in its semantics, forcing writeln to add one
  5560 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5561 string -> unit if you really want to output text without newline;
  5562 
  5563 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5564 plain output, interface builders may have to enable 'isabelle_font'
  5565 mode to get Isabelle font glyphs as before;
  5566 
  5567 * refined token_translation interface; INCOMPATIBILITY: output length
  5568 now of type real instead of int;
  5569 
  5570 * theory loader actions may be traced via new ThyInfo.add_hook
  5571 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5572 your own database of information attached to *whole* theories -- as
  5573 opposed to intra-theory data slots offered via TheoryDataFun;
  5574 
  5575 * proper handling of dangling sort hypotheses (at last!);
  5576 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5577 extra sort hypotheses that can be witnessed from the type signature;
  5578 the force_strip_shyps flag is gone, any remaining shyps are simply
  5579 left in the theorem (with a warning issued by strip_shyps_warning);
  5580 
  5581 
  5582 
  5583 New in Isabelle98-1 (October 1998)
  5584 ----------------------------------
  5585 
  5586 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5587 
  5588 * several changes of automated proof tools;
  5589 
  5590 * HOL: major changes to the inductive and datatype packages, including
  5591 some minor incompatibilities of theory syntax;
  5592 
  5593 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5594 called `inj_on';
  5595 
  5596 * HOL: removed duplicate thms in Arith:
  5597   less_imp_add_less  should be replaced by  trans_less_add1
  5598   le_imp_add_le      should be replaced by  trans_le_add1
  5599 
  5600 * HOL: unary minus is now overloaded (new type constraints may be
  5601 required);
  5602 
  5603 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5604 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5605 now taken as an integer constant.
  5606 
  5607 * Pure: ML function 'theory_of' renamed to 'theory';
  5608 
  5609 
  5610 *** Proof tools ***
  5611 
  5612 * Simplifier:
  5613   1. Asm_full_simp_tac is now more aggressive.
  5614      1. It will sometimes reorient premises if that increases their power to
  5615         simplify.
  5616      2. It does no longer proceed strictly from left to right but may also
  5617         rotate premises to achieve further simplification.
  5618      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5619      old Asm_full_simp_tac in that it does not rotate premises.
  5620   2. The simplifier now knows a little bit about nat-arithmetic.
  5621 
  5622 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5623 allows for selected deletion of wrappers, by introduction of names for
  5624 wrapper functionals.  This implies that addbefore, addSbefore,
  5625 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5626 and that adding two tactics with the same name overwrites the first
  5627 one (emitting a warning).
  5628   type wrapper = (int -> tactic) -> (int -> tactic)
  5629   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5630   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5631   delWrapper, delSWrapper: claset *  string            -> claset
  5632   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5633 
  5634 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5635 semantics; addbefore now affects only the unsafe part of step_tac
  5636 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5637 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5638 by Force_tac;
  5639 
  5640 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5641 compWrapper; added safe wrapper (and access functions for it);
  5642 
  5643 * HOL/split_all_tac is now much faster and fails if there is nothing
  5644 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5645 and the names of the automatically generated variables have changed.
  5646 split_all_tac has moved within claset() from unsafe wrappers to safe
  5647 wrappers, which means that !!-bound variables are split much more
  5648 aggressively, and safe_tac and clarify_tac now split such variables.
  5649 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5650 Note: the same holds for record_split_tac, which does the job of
  5651 split_all_tac for record fields.
  5652 
  5653 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5654 permanently to the default simpset using Addsplits just like
  5655 Addsimps. They can be removed via Delsplits just like
  5656 Delsimps. Lower-case versions are also available.
  5657 
  5658 * HOL/Simplifier: The rule split_if is now part of the default
  5659 simpset. This means that the simplifier will eliminate all occurrences
  5660 of if-then-else in the conclusion of a goal. To prevent this, you can
  5661 either remove split_if completely from the default simpset by
  5662 `Delsplits [split_if]' or remove it in a specific call of the
  5663 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5664 other case splitting rules to/from the default simpset: every datatype
  5665 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5666 t is the name of the datatype).
  5667 
  5668 * Classical reasoner / Simplifier combination: new force_tac (and
  5669 derivatives Force_tac, force) combines rewriting and classical
  5670 reasoning (and whatever other tools) similarly to auto_tac, but is
  5671 aimed to solve the given subgoal completely.
  5672 
  5673 
  5674 *** General ***
  5675 
  5676 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5677 and `goalw': the theory is no longer needed as an explicit argument -
  5678 the current theory context is used; assumptions are no longer returned
  5679 at the ML-level unless one of them starts with ==> or !!; it is
  5680 recommended to convert to these new commands using isatool fixgoal
  5681 (backup your sources first!);
  5682 
  5683 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5684 the current theory context, and 'theory' to lookup stored theories;
  5685 
  5686 * new theory section 'locale' for declaring constants, assumptions and
  5687 definitions that have local scope;
  5688 
  5689 * new theory section 'nonterminals' for purely syntactic types;
  5690 
  5691 * new theory section 'setup' for generic ML setup functions
  5692 (e.g. package initialization);
  5693 
  5694 * the distribution now includes Isabelle icons: see
  5695 lib/logo/isabelle-{small,tiny}.xpm;
  5696 
  5697 * isatool install - install binaries with absolute references to
  5698 ISABELLE_HOME/bin;
  5699 
  5700 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5701 
  5702 * print mode 'emacs' reserved for Isamode;
  5703 
  5704 * support multiple print (ast) translations per constant name;
  5705 
  5706 * theorems involving oracles are now printed with a suffixed [!];
  5707 
  5708 
  5709 *** HOL ***
  5710 
  5711 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5712 
  5713 * HOL/inductive package reorganized and improved: now supports mutual
  5714 definitions such as
  5715 
  5716   inductive EVEN ODD
  5717     intrs
  5718       null "0 : EVEN"
  5719       oddI "n : EVEN ==> Suc n : ODD"
  5720       evenI "n : ODD ==> Suc n : EVEN"
  5721 
  5722 new theorem list "elims" contains an elimination rule for each of the
  5723 recursive sets; inductive definitions now handle disjunctive premises
  5724 correctly (also ZF);
  5725 
  5726 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5727 "mutual_induct" no longer exists - the induction rule is always
  5728 contained in "induct";
  5729 
  5730 
  5731 * HOL/datatype package re-implemented and greatly improved: now
  5732 supports mutually recursive datatypes such as
  5733 
  5734   datatype
  5735     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5736             | SUM ('a aexp) ('a aexp)
  5737             | DIFF ('a aexp) ('a aexp)
  5738             | NUM 'a
  5739   and
  5740     'a bexp = LESS ('a aexp) ('a aexp)
  5741             | AND ('a bexp) ('a bexp)
  5742             | OR ('a bexp) ('a bexp)
  5743 
  5744 as well as indirectly recursive datatypes such as
  5745 
  5746   datatype
  5747     ('a, 'b) term = Var 'a
  5748                   | App 'b ((('a, 'b) term) list)
  5749 
  5750 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5751 induction on mutually / indirectly recursive datatypes.
  5752 
  5753 Primrec equations are now stored in theory and can be accessed via
  5754 <function_name>.simps.
  5755 
  5756 INCOMPATIBILITIES:
  5757 
  5758   - Theories using datatypes must now have theory Datatype as an
  5759     ancestor.
  5760   - The specific <typename>.induct_tac no longer exists - use the
  5761     generic induct_tac instead.
  5762   - natE has been renamed to nat.exhaust - use exhaust_tac
  5763     instead of res_inst_tac ... natE. Note that the variable
  5764     names in nat.exhaust differ from the names in natE, this
  5765     may cause some "fragile" proofs to fail.
  5766   - The theorems split_<typename>_case and split_<typename>_case_asm
  5767     have been renamed to <typename>.split and <typename>.split_asm.
  5768   - Since default sorts of type variables are now handled correctly,
  5769     some datatype definitions may have to be annotated with explicit
  5770     sort constraints.
  5771   - Primrec definitions no longer require function name and type
  5772     of recursive argument.
  5773 
  5774 Consider using isatool fixdatatype to adapt your theories and proof
  5775 scripts to the new package (backup your sources first!).
  5776 
  5777 
  5778 * HOL/record package: considerably improved implementation; now
  5779 includes concrete syntax for record types, terms, updates; theorems
  5780 for surjective pairing and splitting !!-bound record variables; proof
  5781 support is as follows:
  5782 
  5783   1) standard conversions (selectors or updates applied to record
  5784 constructor terms) are part of the standard simpset;
  5785 
  5786   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5787 made part of standard simpset and claset via addIffs;
  5788 
  5789   3) a tactic for record field splitting (record_split_tac) is part of
  5790 the standard claset (addSWrapper);
  5791 
  5792 To get a better idea about these rules you may retrieve them via
  5793 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5794 the name of your record type.
  5795 
  5796 The split tactic 3) conceptually simplifies by the following rule:
  5797 
  5798   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5799 
  5800 Thus any record variable that is bound by meta-all will automatically
  5801 blow up into some record constructor term, consequently the
  5802 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5803 solve record problems automatically.
  5804 
  5805 
  5806 * reorganized the main HOL image: HOL/Integ and String loaded by
  5807 default; theory Main includes everything;
  5808 
  5809 * automatic simplification of integer sums and comparisons, using cancellation;
  5810 
  5811 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5812 
  5813 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5814 
  5815 * many new identities for unions, intersections, set difference, etc.;
  5816 
  5817 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5818 called split_if, split_split, split_sum_case and split_nat_case (to go
  5819 with add/delsplits);
  5820 
  5821 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5822 (?x::unit) = (); this is made part of the default simpset, which COULD
  5823 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5824 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5825 unit_abs_eta_conv is added in order to counter the effect of
  5826 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5827 %u.f();
  5828 
  5829 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5830 makes more sense);
  5831 
  5832 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5833   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5834   disjointness reasoning but breaking a few old proofs.
  5835 
  5836 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5837 to 'converse' from 'inverse' (for compatibility with ZF and some
  5838 literature);
  5839 
  5840 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5841 the well-founded relation;
  5842 
  5843 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5844     Compl A.  The "Compl" syntax remains available as input syntax for this
  5845     release ONLY.
  5846 
  5847 * HOL/Update: new theory of function updates:
  5848     f(a:=b) == %x. if x=a then b else f x
  5849 may also be iterated as in f(a:=b,c:=d,...);
  5850 
  5851 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5852 
  5853 * HOL/List:
  5854   - new function list_update written xs[i:=v] that updates the i-th
  5855     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5856   - new function `upt' written [i..j(] which generates the list
  5857     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5858     bound write [i..j], which is a shorthand for [i..j+1(].
  5859   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5860 
  5861 * HOL/Arith:
  5862   - removed 'pred' (predecessor) function;
  5863   - generalized some theorems about n-1;
  5864   - many new laws about "div" and "mod";
  5865   - new laws about greatest common divisors (see theory ex/Primes);
  5866 
  5867 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5868 instead of "inverse";
  5869 
  5870 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5871   of the multiset ordering;
  5872 
  5873 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5874   (not included by default);
  5875 
  5876 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5877 
  5878 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5879   programs, i.e. different program variables may have different types.
  5880 
  5881 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5882   [previously, this check worked only if the rewrite rule was unconditional]
  5883   Now rew can involve either definitions or equalities (either == or =).
  5884 
  5885 
  5886 *** ZF ***
  5887 
  5888 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5889   only the theorems proved on ZF.ML;
  5890 
  5891 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5892   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5893   disjointness reasoning but breaking a few old proofs.
  5894 
  5895 * ZF/Update: new theory of function updates
  5896     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5897   may also be iterated as in f(a:=b,c:=d,...);
  5898 
  5899 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5900 
  5901 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5902   [previously, this check worked only if the rewrite rule was unconditional]
  5903   Now rew can involve either definitions or equalities (either == or =).
  5904 
  5905 * case_tac provided for compatibility with HOL
  5906     (like the old excluded_middle_tac, but with subgoals swapped)
  5907 
  5908 
  5909 *** Internal programming interfaces ***
  5910 
  5911 * Pure: several new basic modules made available for general use, see
  5912 also src/Pure/README;
  5913 
  5914 * improved the theory data mechanism to support encapsulation (data
  5915 kind name replaced by private Object.kind, acting as authorization
  5916 key); new type-safe user interface via functor TheoryDataFun; generic
  5917 print_data function becomes basically useless;
  5918 
  5919 * removed global_names compatibility flag -- all theory declarations
  5920 are qualified by default;
  5921 
  5922 * module Pure/Syntax now offers quote / antiquote translation
  5923 functions (useful for Hoare logic etc. with implicit dependencies);
  5924 see HOL/ex/Antiquote for an example use;
  5925 
  5926 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5927 cterm -> thm;
  5928 
  5929 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5930 subgoal;
  5931 
  5932 * Display.print_goals function moved to Locale.print_goals;
  5933 
  5934 * standard print function for goals supports current_goals_markers
  5935 variable for marking begin of proof, end of proof, start of goal; the
  5936 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5937 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5938 for example;
  5939 
  5940 
  5941 
  5942 New in Isabelle98 (January 1998)
  5943 --------------------------------
  5944 
  5945 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5946 
  5947 * changed lexical syntax of terms / types: dots made part of long
  5948 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5949 
  5950 * simpset (and claset) reference variable replaced by functions
  5951 simpset / simpset_ref;
  5952 
  5953 * no longer supports theory aliases (via merge) and non-trivial
  5954 implicit merge of thms' signatures;
  5955 
  5956 * most internal names of constants changed due to qualified names;
  5957 
  5958 * changed Pure/Sequence interface (see Pure/seq.ML);
  5959 
  5960 
  5961 *** General Changes ***
  5962 
  5963 * hierachically structured name spaces (for consts, types, axms, thms
  5964 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5965 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5966 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5967 long_names for fully qualified output names; NOTE: ML programs
  5968 (special tactics, packages etc.) referring to internal names may have
  5969 to be adapted to cope with fully qualified names; in case of severe
  5970 backward campatibility problems try setting 'global_names' at compile
  5971 time to have enrything declared within a flat name space; one may also
  5972 fine tune name declarations in theories via the 'global' and 'local'
  5973 section;
  5974 
  5975 * reimplemented the implicit simpset and claset using the new anytype
  5976 data filed in signatures; references simpset:simpset ref etc. are
  5977 replaced by functions simpset:unit->simpset and
  5978 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5979 to patch your ML files accordingly;
  5980 
  5981 * HTML output now includes theory graph data for display with Java
  5982 applet or isatool browser; data generated automatically via isatool
  5983 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5984 
  5985 * defs may now be conditional; improved rewrite_goals_tac to handle
  5986 conditional equations;
  5987 
  5988 * defs now admits additional type arguments, using TYPE('a) syntax;
  5989 
  5990 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5991 creates a new theory node; implicit merge of thms' signatures is
  5992 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5993 transfer:theory->thm->thm in (rare) cases;
  5994 
  5995 * improved handling of draft signatures / theories; draft thms (and
  5996 ctyps, cterms) are automatically promoted to real ones;
  5997 
  5998 * slightly changed interfaces for oracles: admit many per theory, named
  5999 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6000 
  6001 * print_goals: optional output of const types (set show_consts and
  6002 show_types);
  6003 
  6004 * improved output of warnings (###) and errors (***);
  6005 
  6006 * subgoal_tac displays a warning if the new subgoal has type variables;
  6007 
  6008 * removed old README and Makefiles;
  6009 
  6010 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6011 
  6012 * removed obsolete init_pps and init_database;
  6013 
  6014 * deleted the obsolete tactical STATE, which was declared by
  6015     fun STATE tacfun st = tacfun st st;
  6016 
  6017 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6018 (which abbreviates $HOME);
  6019 
  6020 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6021 use isatool fixseq to adapt your ML programs (this works for fully
  6022 qualified references to the Sequence structure only!);
  6023 
  6024 * use_thy no longer requires writable current directory; it always
  6025 reloads .ML *and* .thy file, if either one is out of date;
  6026 
  6027 
  6028 *** Classical Reasoner ***
  6029 
  6030 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6031 tactics that use classical reasoning to simplify a subgoal without
  6032 splitting it into several subgoals;
  6033 
  6034 * Safe_tac: like safe_tac but uses the default claset;
  6035 
  6036 
  6037 *** Simplifier ***
  6038 
  6039 * added simplification meta rules:
  6040     (asm_)(full_)simplify: simpset -> thm -> thm;
  6041 
  6042 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6043 logics (again);
  6044 
  6045 * added prems argument to simplification procedures;
  6046 
  6047 * HOL, FOL, ZF: added infix function `addsplits':
  6048   instead of `<simpset> setloop (split_tac <thms>)'
  6049   you can simply write `<simpset> addsplits <thms>'
  6050 
  6051 
  6052 *** Syntax ***
  6053 
  6054 * TYPE('a) syntax for type reflection terms;
  6055 
  6056 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6057 
  6058 * pretty printer: changed order of mixfix annotation preference (again!);
  6059 
  6060 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6061 
  6062 
  6063 *** HOL ***
  6064 
  6065 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6066   with `addloop' of the simplifier to faciliate case splitting in premises.
  6067 
  6068 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6069 
  6070 * HOL/Auth: new protocol proofs including some for the Internet
  6071   protocol TLS;
  6072 
  6073 * HOL/Map: new theory of `maps' a la VDM;
  6074 
  6075 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6076 cancelling out common nat summands from =, <, <= (in)equalities, or
  6077 differences; simplification procedures nat_cancel_factor for
  6078 cancelling common factor from =, <, <= (in)equalities over natural
  6079 sums; nat_cancel contains both kinds of procedures, it is installed by
  6080 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6081 
  6082 * HOL/simplifier: terms of the form
  6083   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6084   are rewritten to
  6085   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6086   and those of the form
  6087   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6088   are rewritten to
  6089   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6090 
  6091 * HOL/datatype
  6092   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6093 
  6094   P(t_case f1 ... fn x) =
  6095      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6096         ...
  6097        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6098      )
  6099 
  6100   and a theorem `split_t_case_asm' of the form
  6101 
  6102   P(t_case f1 ... fn x) =
  6103     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6104         ...
  6105        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6106      )
  6107   which can be added to a simpset via `addsplits'. The existing theorems
  6108   expand_list_case and expand_option_case have been renamed to
  6109   split_list_case and split_option_case.
  6110 
  6111 * HOL/Arithmetic:
  6112   - `pred n' is automatically converted to `n-1'.
  6113     Users are strongly encouraged not to use `pred' any longer,
  6114     because it will disappear altogether at some point.
  6115   - Users are strongly encouraged to write "0 < n" rather than
  6116     "n ~= 0". Theorems and proof tools have been modified towards this
  6117     `standard'.
  6118 
  6119 * HOL/Lists:
  6120   the function "set_of_list" has been renamed "set" (and its theorems too);
  6121   the function "nth" now takes its arguments in the reverse order and
  6122   has acquired the infix notation "!" as in "xs!n".
  6123 
  6124 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6125 
  6126 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6127   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6128 
  6129 * HOL/record: extensible records with schematic structural subtyping
  6130 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6131 still lacks various theorems and concrete record syntax;
  6132 
  6133 
  6134 *** HOLCF ***
  6135 
  6136 * removed "axioms" and "generated by" sections;
  6137 
  6138 * replaced "ops" section by extended "consts" section, which is capable of
  6139   handling the continuous function space "->" directly;
  6140 
  6141 * domain package:
  6142   . proves theorems immediately and stores them in the theory,
  6143   . creates hierachical name space,
  6144   . now uses normal mixfix annotations (instead of cinfix...),
  6145   . minor changes to some names and values (for consistency),
  6146   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6147   . separator between mutual domain defs: changed "," to "and",
  6148   . improved handling of sort constraints;  now they have to
  6149     appear on the left-hand side of the equations only;
  6150 
  6151 * fixed LAM <x,y,zs>.b syntax;
  6152 
  6153 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6154 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6155 
  6156 
  6157 *** FOL and ZF ***
  6158 
  6159 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6160   with `addloop' of the simplifier to faciliate case splitting in premises.
  6161 
  6162 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6163 in HOL, they strip ALL and --> from proved theorems;
  6164 
  6165 
  6166 
  6167 New in Isabelle94-8 (May 1997)
  6168 ------------------------------
  6169 
  6170 *** General Changes ***
  6171 
  6172 * new utilities to build / run / maintain Isabelle etc. (in parts
  6173 still somewhat experimental); old Makefiles etc. still functional;
  6174 
  6175 * new 'Isabelle System Manual';
  6176 
  6177 * INSTALL text, together with ./configure and ./build scripts;
  6178 
  6179 * reimplemented type inference for greater efficiency, better error
  6180 messages and clean internal interface;
  6181 
  6182 * prlim command for dealing with lots of subgoals (an easier way of
  6183 setting goals_limit);
  6184 
  6185 
  6186 *** Syntax ***
  6187 
  6188 * supports alternative (named) syntax tables (parser and pretty
  6189 printer); internal interface is provided by add_modesyntax(_i);
  6190 
  6191 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6192 be used in conjunction with the Isabelle symbol font; uses the
  6193 "symbols" syntax table;
  6194 
  6195 * added token_translation interface (may translate name tokens in
  6196 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6197 the current print_mode); IMPORTANT: user print translation functions
  6198 are responsible for marking newly introduced bounds
  6199 (Syntax.mark_boundT);
  6200 
  6201 * token translations for modes "xterm" and "xterm_color" that display
  6202 names in bold, underline etc. or colors (which requires a color
  6203 version of xterm);
  6204 
  6205 * infixes may now be declared with names independent of their syntax;
  6206 
  6207 * added typed_print_translation (like print_translation, but may
  6208 access type of constant);
  6209 
  6210 
  6211 *** Classical Reasoner ***
  6212 
  6213 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6214 some limitations.  Blast_tac...
  6215   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6216   + ignores elimination rules that don't have the correct format
  6217         (the conclusion MUST be a formula variable)
  6218   + ignores types, which can make HOL proofs fail
  6219   + rules must not require higher-order unification, e.g. apply_type in ZF
  6220     [message "Function Var's argument not a bound variable" relates to this]
  6221   + its proof strategy is more general but can actually be slower
  6222 
  6223 * substitution with equality assumptions no longer permutes other
  6224 assumptions;
  6225 
  6226 * minor changes in semantics of addafter (now called addaltern); renamed
  6227 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6228 (and access functions for it);
  6229 
  6230 * improved combination of classical reasoner and simplifier:
  6231   + functions for handling clasimpsets
  6232   + improvement of addss: now the simplifier is called _after_ the
  6233     safe steps.
  6234   + safe variant of addss called addSss: uses safe simplifications
  6235     _during_ the safe steps. It is more complete as it allows multiple
  6236     instantiations of unknowns (e.g. with slow_tac).
  6237 
  6238 *** Simplifier ***
  6239 
  6240 * added interface for simplification procedures (functions that
  6241 produce *proven* rewrite rules on the fly, depending on current
  6242 redex);
  6243 
  6244 * ordering on terms as parameter (used for ordered rewriting);
  6245 
  6246 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6247 
  6248 * the solver is now split into a safe and an unsafe part.
  6249 This should be invisible for the normal user, except that the
  6250 functions setsolver and addsolver have been renamed to setSolver and
  6251 addSolver; added safe_asm_full_simp_tac;
  6252 
  6253 
  6254 *** HOL ***
  6255 
  6256 * a generic induction tactic `induc