NEWS
author wenzelm
Tue Aug 04 16:13:16 2009 +0200 (2009-08-04)
changeset 32326 9d70ecf11b7a
parent 32270 615c524bd9e4
child 32365 9b74d0339c44
permissions -rw-r--r--
etc/components;
isabelle makeall operates on all components with IsaMakefile;
     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 * Support for additional "Isabelle components" via etc/components, see
   179 also the system manual.
   180 
   181 * The isabelle makeall tool now operates on all components with
   182 IsaMakefile, not just hardwired "logics".
   183 
   184 * Discontinued support for Poly/ML 4.x versions.
   185 
   186 * Removed "compress" option from isabelle-process and isabelle usedir;
   187 this is always enabled.
   188 
   189 * More fine-grained control of proof parallelism, cf.
   190 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   191 
   192 
   193 
   194 New in Isabelle2009 (April 2009)
   195 --------------------------------
   196 
   197 *** General ***
   198 
   199 * Simplified main Isabelle executables, with less surprises on
   200 case-insensitive file-systems (such as Mac OS).
   201 
   202   - The main Isabelle tool wrapper is now called "isabelle" instead of
   203     "isatool."
   204 
   205   - The former "isabelle" alias for "isabelle-process" has been
   206     removed (should rarely occur to regular users).
   207 
   208   - The former "isabelle-interface" and its alias "Isabelle" have been
   209     removed (interfaces are now regular Isabelle tools).
   210 
   211 Within scripts and make files, the Isabelle environment variables
   212 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   213 respectively.  (The latter are still available as legacy feature.)
   214 
   215 The old isabelle-interface wrapper could react in confusing ways if
   216 the interface was uninstalled or changed otherwise.  Individual
   217 interface tool configuration is now more explicit, see also the
   218 Isabelle system manual.  In particular, Proof General is now available
   219 via "isabelle emacs".
   220 
   221 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   222 purge installed copies of Isabelle executables and re-run "isabelle
   223 install -p ...", or use symlinks.
   224 
   225 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   226 old ~/isabelle, which was slightly non-standard and apt to cause
   227 surprises on case-insensitive file-systems (such as Mac OS).
   228 
   229 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   230 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   231 care is required when using older releases of Isabelle.  Note that
   232 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   233 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   234 
   235 * Proofs of fully specified statements are run in parallel on
   236 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   237 a regular 4-core machine, if the initial heap space is made reasonably
   238 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   239 
   240 * The main reference manuals ("isar-ref", "implementation", and
   241 "system") have been updated and extended.  Formally checked references
   242 as hyperlinks are now available uniformly.
   243 
   244 
   245 *** Pure ***
   246 
   247 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   248 respects.  The most important changes are listed below.  See the
   249 Tutorial on Locales ("locales" manual) for details.
   250 
   251 - In locale expressions, instantiation replaces renaming.  Parameters
   252 must be declared in a for clause.  To aid compatibility with previous
   253 parameter inheritance, in locale declarations, parameters that are not
   254 'touched' (instantiation position "_" or omitted) are implicitly added
   255 with their syntax at the beginning of the for clause.
   256 
   257 - Syntax from abbreviations and definitions in locales is available in
   258 locale expressions and context elements.  The latter is particularly
   259 useful in locale declarations.
   260 
   261 - More flexible mechanisms to qualify names generated by locale
   262 expressions.  Qualifiers (prefixes) may be specified in locale
   263 expressions, and can be marked as mandatory (syntax: "name!:") or
   264 optional (syntax "name?:").  The default depends for plain "name:"
   265 depends on the situation where a locale expression is used: in
   266 commands 'locale' and 'sublocale' prefixes are optional, in
   267 'interpretation' and 'interpret' prefixes are mandatory.  The old
   268 implicit qualifiers derived from the parameter names of a locale are
   269 no longer generated.
   270 
   271 - Command "sublocale l < e" replaces "interpretation l < e".  The
   272 instantiation clause in "interpretation" and "interpret" (square
   273 brackets) is no longer available.  Use locale expressions.
   274 
   275 - When converting proof scripts, mandatory qualifiers in
   276 'interpretation' and 'interpret' should be retained by default, even
   277 if this is an INCOMPATIBILITY compared to former behavior.  In the
   278 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   279 in locale expressions range over a single locale instance only.
   280 
   281 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   282 In existing theorem specifications replace the includes element by the
   283 respective context elements of the included locale, omitting those
   284 that are already present in the theorem specification.  Multiple
   285 assume elements of a locale should be replaced by a single one
   286 involving the locale predicate.  In the proof body, declarations (most
   287 notably theorems) may be regained by interpreting the respective
   288 locales in the proof context as required (command "interpret").
   289 
   290 If using "includes" in replacement of a target solely because the
   291 parameter types in the theorem are not as general as in the target,
   292 consider declaring a new locale with additional type constraints on
   293 the parameters (context element "constrains").
   294 
   295 - Discontinued "locale (open)".  INCOMPATIBILITY.
   296 
   297 - Locale interpretation commands no longer attempt to simplify goal.
   298 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   299 methods intro_locales and unfold_locales to clarify.
   300 
   301 - Locale interpretation commands no longer accept interpretation
   302 attributes.  INCOMPATIBILITY.
   303 
   304 * Class declaration: so-called "base sort" must not be given in import
   305 list any longer, but is inferred from the specification.  Particularly
   306 in HOL, write
   307 
   308     class foo = ...
   309 
   310 instead of
   311 
   312     class foo = type + ...
   313 
   314 * Class target: global versions of theorems stemming do not carry a
   315 parameter prefix any longer.  INCOMPATIBILITY.
   316 
   317 * Class 'instance' command no longer accepts attached definitions.
   318 INCOMPATIBILITY, use proper 'instantiation' target instead.
   319 
   320 * Recovered hiding of consts, which was accidentally broken in
   321 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   322 makes c inaccessible; consider using ``hide (open) const c'' instead.
   323 
   324 * Slightly more coherent Pure syntax, with updated documentation in
   325 isar-ref manual.  Removed locales meta_term_syntax and
   326 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   327 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   328 directly in regular applications.
   329 
   330 * There is a new syntactic category "float_const" for signed decimal
   331 fractions (e.g. 123.45 or -123.45).
   332 
   333 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   334 interface with 'setup' command instead.
   335 
   336 * Command 'local_setup' is similar to 'setup', but operates on a local
   337 theory context.
   338 
   339 * The 'axiomatization' command now only works within a global theory
   340 context.  INCOMPATIBILITY.
   341 
   342 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   343 hypotheses.  Sorts required in the course of reasoning need to be
   344 covered by the constraints in the initial statement, completed by the
   345 type instance information of the background theory.  Non-trivial sort
   346 hypotheses, which rarely occur in practice, may be specified via
   347 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   348 
   349   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   350 
   351 The result contains an implicit sort hypotheses as before --
   352 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   353 normalization.
   354 
   355 * Generalized Isar history, with support for linear undo, direct state
   356 addressing etc.
   357 
   358 * Changed defaults for unify configuration options:
   359 
   360   unify_trace_bound = 50 (formerly 25)
   361   unify_search_bound = 60 (formerly 30)
   362 
   363 * Different bookkeeping for code equations (INCOMPATIBILITY):
   364 
   365   a) On theory merge, the last set of code equations for a particular
   366      constant is taken (in accordance with the policy applied by other
   367      parts of the code generator framework).
   368 
   369   b) Code equations stemming from explicit declarations (e.g. code
   370      attribute) gain priority over default code equations stemming
   371      from definition, primrec, fun etc.
   372 
   373 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   374 
   375 * Unified theorem tables for both code generators.  Thus [code
   376 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   377 
   378 * Command 'find_consts' searches for constants based on type and name
   379 patterns, e.g.
   380 
   381     find_consts "_ => bool"
   382 
   383 By default, matching is against subtypes, but it may be restricted to
   384 the whole type.  Searching by name is possible.  Multiple queries are
   385 conjunctive and queries may be negated by prefixing them with a
   386 hyphen:
   387 
   388     find_consts strict: "_ => bool" name: "Int" -"int => int"
   389 
   390 * New 'find_theorems' criterion "solves" matches theorems that
   391 directly solve the current goal (modulo higher-order unification).
   392 
   393 * Auto solve feature for main theorem statements: whenever a new goal
   394 is stated, "find_theorems solves" is called; any theorems that could
   395 solve the lemma directly are listed as part of the goal state.
   396 Cf. associated options in Proof General Isabelle settings menu,
   397 enabled by default, with reasonable timeout for pathological cases of
   398 higher-order unification.
   399 
   400 
   401 *** Document preparation ***
   402 
   403 * Antiquotation @{lemma} now imitates a regular terminal proof,
   404 demanding keyword 'by' and supporting the full method expression
   405 syntax just like the Isar command 'by'.
   406 
   407 
   408 *** HOL ***
   409 
   410 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   411 points Main and Complex_Main remain as before.
   412 
   413 * Logic image HOL-Plain provides a minimal HOL with the most important
   414 tools available (inductive, datatype, primrec, ...).  This facilitates
   415 experimentation and tool development.  Note that user applications
   416 (and library theories) should never refer to anything below theory
   417 Main, as before.
   418 
   419 * Logic image HOL-Main stops at theory Main, and thus facilitates
   420 experimentation due to shorter build times.
   421 
   422 * Logic image HOL-NSA contains theories of nonstandard analysis which
   423 were previously part of former HOL-Complex.  Entry point Hyperreal
   424 remains valid, but theories formerly using Complex_Main should now use
   425 new entry point Hypercomplex.
   426 
   427 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   428 Posix processes.  Avoids potentially expensive forking of the ML
   429 process.  New thread-based implementation also works on non-Unix
   430 platforms (Cygwin).  Provers are no longer hardwired, but defined
   431 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   432 commands are covered in the isar-ref manual.
   433 
   434 * Wrapper scripts for remote SystemOnTPTP service allows to use
   435 sledgehammer without local ATP installation (Vampire etc.). Other
   436 provers may be included via suitable ML wrappers, see also
   437 src/HOL/ATP_Linkup.thy.
   438 
   439 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   440 menu.
   441 
   442 * The metis method no longer fails because the theorem is too trivial
   443 (contains the empty clause).
   444 
   445 * The metis method now fails in the usual manner, rather than raising
   446 an exception, if it determines that it cannot prove the theorem.
   447 
   448 * Method "coherent" implements a prover for coherent logic (see also
   449 src/Tools/coherent.ML).
   450 
   451 * Constants "undefined" and "default" replace "arbitrary".  Usually
   452 "undefined" is the right choice to replace "arbitrary", though
   453 logically there is no difference.  INCOMPATIBILITY.
   454 
   455 * Command "value" now integrates different evaluation mechanisms.  The
   456 result of the first successful evaluation mechanism is printed.  In
   457 square brackets a particular named evaluation mechanisms may be
   458 specified (currently, [SML], [code] or [nbe]).  See further
   459 src/HOL/ex/Eval_Examples.thy.
   460 
   461 * Normalization by evaluation now allows non-leftlinear equations.
   462 Declare with attribute [code nbe].
   463 
   464 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   465 as the structured Isar versions "cases" and "induct", cf. the
   466 corresponding "cases" and "induct" attributes.  Mutual induction rules
   467 are now presented as a list of individual projections
   468 (e.g. foo_bar.inducts for types foo and bar); the old format with
   469 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   470 rare situations a different rule is selected --- notably nested tuple
   471 elimination instead of former prod.exhaust: use explicit (case_tac t
   472 rule: prod.exhaust) here.
   473 
   474 * Attributes "cases", "induct", "coinduct" support "del" option.
   475 
   476 * Removed fact "case_split_thm", which duplicates "case_split".
   477 
   478 * The option datatype has been moved to a new theory Option.  Renamed
   479 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   480 
   481 * New predicate "strict_mono" classifies strict functions on partial
   482 orders.  With strict functions on linear orders, reasoning about
   483 (in)equalities is facilitated by theorems "strict_mono_eq",
   484 "strict_mono_less_eq" and "strict_mono_less".
   485 
   486 * Some set operations are now proper qualified constants with
   487 authentic syntax.  INCOMPATIBILITY:
   488 
   489     op Int ~>   Set.Int
   490     op Un ~>    Set.Un
   491     INTER ~>    Set.INTER
   492     UNION ~>    Set.UNION
   493     Inter ~>    Set.Inter
   494     Union ~>    Set.Union
   495     {} ~>       Set.empty
   496     UNIV ~>     Set.UNIV
   497 
   498 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   499 theory Set.
   500 
   501 * Auxiliary class "itself" has disappeared -- classes without any
   502 parameter are treated as expected by the 'class' command.
   503 
   504 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   505 
   506 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   507 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   508 
   509 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   510 method "approximation".  It proves formulas on real values by using
   511 interval arithmetic.  In the formulas are also the transcendental
   512 functions sin, cos, tan, atan, ln, exp and the constant pi are
   513 allowed. For examples see
   514 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   515 
   516 * Theory "Reflection" now resides in HOL/Library.
   517 
   518 * Entry point to Word library now simply named "Word".
   519 INCOMPATIBILITY.
   520 
   521 * Made source layout more coherent with logical distribution
   522 structure:
   523 
   524     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   525     src/HOL/Library/Code_Message.thy ~> src/HOL/
   526     src/HOL/Library/GCD.thy ~> src/HOL/
   527     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   528     src/HOL/Library/Parity.thy ~> src/HOL/
   529     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   530     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   531     src/HOL/Real/Lubs.thy ~> src/HOL/
   532     src/HOL/Real/PReal.thy ~> src/HOL/
   533     src/HOL/Real/Rational.thy ~> src/HOL/
   534     src/HOL/Real/RComplete.thy ~> src/HOL/
   535     src/HOL/Real/RealDef.thy ~> src/HOL/
   536     src/HOL/Real/RealPow.thy ~> src/HOL/
   537     src/HOL/Real/Real.thy ~> src/HOL/
   538     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   539     src/HOL/Complex/Complex.thy ~> src/HOL/
   540     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   541     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   542     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   543     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   544     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   545     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   546     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   547     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   548     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   549     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   550     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   551     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   552     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   553     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   554     src/HOL/Real/Float ~> src/HOL/Library/
   555     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   556     src/HOL/Real/RealVector.thy ~> src/HOL/
   557 
   558     src/HOL/arith_data.ML ~> src/HOL/Tools
   559     src/HOL/hologic.ML ~> src/HOL/Tools
   560     src/HOL/simpdata.ML ~> src/HOL/Tools
   561     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   562     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   563     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   564     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   565     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   566     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   567     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   568 
   569     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   570     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   571     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   572     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   573     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   574     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   575 
   576 * If methods "eval" and "evaluation" encounter a structured proof
   577 state with !!/==>, only the conclusion is evaluated to True (if
   578 possible), avoiding strange error messages.
   579 
   580 * Method "sizechange" automates termination proofs using (a
   581 modification of) the size-change principle.  Requires SAT solver.  See
   582 src/HOL/ex/Termination.thy for examples.
   583 
   584 * Simplifier: simproc for let expressions now unfolds if bound
   585 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   586 
   587 * Method "arith": Linear arithmetic now ignores all inequalities when
   588 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   589 
   590 * New attribute "arith" for facts that should always be used
   591 automatically by arithmetic. It is intended to be used locally in
   592 proofs, e.g.
   593 
   594   assumes [arith]: "x > 0"
   595 
   596 Global usage is discouraged because of possible performance impact.
   597 
   598 * New classes "top" and "bot" with corresponding operations "top" and
   599 "bot" in theory Orderings; instantiation of class "complete_lattice"
   600 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   601 
   602 * Changed definition lemma "less_fun_def" in order to provide an
   603 instance for preorders on functions; use lemma "less_le" instead.
   604 INCOMPATIBILITY.
   605 
   606 * Theory Orderings: class "wellorder" moved here, with explicit
   607 induction rule "less_induct" as assumption.  For instantiation of
   608 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   609 INCOMPATIBILITY.
   610 
   611 * Theory Orderings: added class "preorder" as superclass of "order".
   612 INCOMPATIBILITY: Instantiation proofs for order, linorder
   613 etc. slightly changed.  Some theorems named order_class.* now named
   614 preorder_class.*.
   615 
   616 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   617 "diag" to "Id_on".
   618 
   619 * Theory Finite_Set: added a new fold combinator of type
   620 
   621   ('a => 'b => 'b) => 'b => 'a set => 'b
   622 
   623 Occasionally this is more convenient than the old fold combinator
   624 which is now defined in terms of the new one and renamed to
   625 fold_image.
   626 
   627 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   628 and "ring_simps" have been replaced by "algebra_simps" (which can be
   629 extended with further lemmas!).  At the moment both still exist but
   630 the former will disappear at some point.
   631 
   632 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   633 class recpower.  Type-specific simp rules for various recpower types
   634 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   635 
   636 rat_power_0    -> power_0
   637 rat_power_Suc  -> power_Suc
   638 realpow_0      -> power_0
   639 realpow_Suc    -> power_Suc
   640 complexpow_0   -> power_0
   641 complexpow_Suc -> power_Suc
   642 power_poly_0   -> power_0
   643 power_poly_Suc -> power_Suc
   644 
   645 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   646 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   647 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   648 of lemmas from Divides has been generalized from nat to class
   649 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   650 renames resulting from duplicate elimination:
   651 
   652     dvd_def_mod ~>          dvd_eq_mod_eq_0
   653     zero_dvd_iff ~>         dvd_0_left_iff
   654     dvd_0 ~>                dvd_0_right
   655     DIVISION_BY_ZERO_DIV ~> div_by_0
   656     DIVISION_BY_ZERO_MOD ~> mod_by_0
   657     mult_div ~>             div_mult_self2_is_id
   658     mult_mod ~>             mod_mult_self2_is_0
   659 
   660 * Theory IntDiv: removed many lemmas that are instances of class-based
   661 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   662 rename old lemmas as follows:
   663 
   664 dvd_diff               -> nat_dvd_diff
   665 dvd_zminus_iff         -> dvd_minus_iff
   666 mod_add1_eq            -> mod_add_eq
   667 mod_mult1_eq           -> mod_mult_right_eq
   668 mod_mult1_eq'          -> mod_mult_left_eq
   669 mod_mult_distrib_mod   -> mod_mult_eq
   670 nat_mod_add_left_eq    -> mod_add_left_eq
   671 nat_mod_add_right_eq   -> mod_add_right_eq
   672 nat_mod_div_trivial    -> mod_div_trivial
   673 nat_mod_mod_trivial    -> mod_mod_trivial
   674 zdiv_zadd_self1        -> div_add_self1
   675 zdiv_zadd_self2        -> div_add_self2
   676 zdiv_zmult_self1       -> div_mult_self2_is_id
   677 zdiv_zmult_self2       -> div_mult_self1_is_id
   678 zdvd_triv_left         -> dvd_triv_left
   679 zdvd_triv_right        -> dvd_triv_right
   680 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   681 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   682 zmod_zadd_left_eq      -> mod_add_left_eq
   683 zmod_zadd_right_eq     -> mod_add_right_eq
   684 zmod_zadd_self1        -> mod_add_self1
   685 zmod_zadd_self2        -> mod_add_self2
   686 zmod_zadd1_eq          -> mod_add_eq
   687 zmod_zdiff1_eq         -> mod_diff_eq
   688 zmod_zdvd_zmod         -> mod_mod_cancel
   689 zmod_zmod_cancel       -> mod_mod_cancel
   690 zmod_zmult_self1       -> mod_mult_self2_is_0
   691 zmod_zmult_self2       -> mod_mult_self1_is_0
   692 zmod_1                 -> mod_by_1
   693 zdiv_1                 -> div_by_1
   694 zdvd_abs1              -> abs_dvd_iff
   695 zdvd_abs2              -> dvd_abs_iff
   696 zdvd_refl              -> dvd_refl
   697 zdvd_trans             -> dvd_trans
   698 zdvd_zadd              -> dvd_add
   699 zdvd_zdiff             -> dvd_diff
   700 zdvd_zminus_iff        -> dvd_minus_iff
   701 zdvd_zminus2_iff       -> minus_dvd_iff
   702 zdvd_zmultD            -> dvd_mult_right
   703 zdvd_zmultD2           -> dvd_mult_left
   704 zdvd_zmult_mono        -> mult_dvd_mono
   705 zdvd_0_right           -> dvd_0_right
   706 zdvd_0_left            -> dvd_0_left_iff
   707 zdvd_1_left            -> one_dvd
   708 zminus_dvd_iff         -> minus_dvd_iff
   709 
   710 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   711 
   712 * The real numbers offer decimal input syntax: 12.34 is translated
   713 into 1234/10^2. This translation is not reversed upon output.
   714 
   715 * Theory Library/Polynomial defines an abstract type 'a poly of
   716 univariate polynomials with coefficients of type 'a.  In addition to
   717 the standard ring operations, it also supports div and mod.  Code
   718 generation is also supported, using list-style constructors.
   719 
   720 * Theory Library/Inner_Product defines a class of real_inner for real
   721 inner product spaces, with an overloaded operation inner :: 'a => 'a
   722 => real.  Class real_inner is a subclass of real_normed_vector from
   723 theory RealVector.
   724 
   725 * Theory Library/Product_Vector provides instances for the product
   726 type 'a * 'b of several classes from RealVector and Inner_Product.
   727 Definitions of addition, subtraction, scalar multiplication, norms,
   728 and inner products are included.
   729 
   730 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   731 addition to the field operations, numerals and case syntax are also
   732 supported.
   733 
   734 * Theory Library/Diagonalize provides constructive version of Cantor's
   735 first diagonalization argument.
   736 
   737 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   738 zlcm (for int); carried together from various gcd/lcm developements in
   739 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   740 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   741 may recover tupled syntax as follows:
   742 
   743     hide (open) const gcd
   744     abbreviation gcd where
   745       "gcd == (%(a, b). GCD.gcd a b)"
   746     notation (output)
   747       GCD.gcd ("gcd '(_, _')")
   748 
   749 The same works for lcm, zgcd, zlcm.
   750 
   751 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   752 instantiations for algebraic structures.  Removed some duplicate
   753 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   754 
   755 * ML antiquotation @{code} takes a constant as argument and generates
   756 corresponding code in background and inserts name of the corresponding
   757 resulting ML value/function/datatype constructor binding in place.
   758 All occurrences of @{code} with a single ML block are generated
   759 simultaneously.  Provides a generic and safe interface for
   760 instrumentalizing code generation.  See
   761 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   762 In future you ought to refrain from ad-hoc compiling generated SML
   763 code on the ML toplevel.  Note that (for technical reasons) @{code}
   764 cannot refer to constants for which user-defined serializations are
   765 set.  Refer to the corresponding ML counterpart directly in that
   766 cases.
   767 
   768 * Command 'rep_datatype': instead of theorem names the command now
   769 takes a list of terms denoting the constructors of the type to be
   770 represented as datatype.  The characteristic theorems have to be
   771 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   772 have disappeared in favour of existing ones:
   773 
   774     unit_induct                 ~> unit.induct
   775     prod_induct                 ~> prod.induct
   776     sum_induct                  ~> sum.induct
   777     Suc_Suc_eq                  ~> nat.inject
   778     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   779 
   780 
   781 *** HOL-Algebra ***
   782 
   783 * New locales for orders and lattices where the equivalence relation
   784 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   785 locales use a record structure with field eq for the equivalence.
   786 
   787 * New theory of factorial domains.
   788 
   789 * Units_l_inv and Units_r_inv are now simp rules by default.
   790 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   791 and/or r_inv will now also require deletion of these lemmas.
   792 
   793 * Renamed the following theorems, INCOMPATIBILITY:
   794 
   795 UpperD ~> Upper_memD
   796 LowerD ~> Lower_memD
   797 least_carrier ~> least_closed
   798 greatest_carrier ~> greatest_closed
   799 greatest_Lower_above ~> greatest_Lower_below
   800 one_zero ~> carrier_one_zero
   801 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   802 
   803 
   804 *** HOL-Nominal ***
   805 
   806 * Nominal datatypes can now contain type-variables.
   807 
   808 * Commands 'nominal_inductive' and 'equivariance' work with local
   809 theory targets.
   810 
   811 * Nominal primrec can now works with local theory targets and its
   812 specification syntax now conforms to the general format as seen in
   813 'inductive' etc.
   814 
   815 * Method "perm_simp" honours the standard simplifier attributes
   816 (no_asm), (no_asm_use) etc.
   817 
   818 * The new predicate #* is defined like freshness, except that on the
   819 left hand side can be a set or list of atoms.
   820 
   821 * Experimental command 'nominal_inductive2' derives strong induction
   822 principles for inductive definitions.  In contrast to
   823 'nominal_inductive', which can only deal with a fixed number of
   824 binders, it can deal with arbitrary expressions standing for sets of
   825 atoms to be avoided.  The only inductive definition we have at the
   826 moment that needs this generalisation is the typing rule for Lets in
   827 the algorithm W:
   828 
   829  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   830  -----------------------------------------------------------------
   831          Gamma |- Let x be t1 in t2 : T2
   832 
   833 In this rule one wants to avoid all the binders that are introduced by
   834 "close Gamma T1".  We are looking for other examples where this
   835 feature might be useful.  Please let us know.
   836 
   837 
   838 *** HOLCF ***
   839 
   840 * Reimplemented the simplification procedure for proving continuity
   841 subgoals.  The new simproc is extensible; users can declare additional
   842 continuity introduction rules with the attribute [cont2cont].
   843 
   844 * The continuity simproc now uses a different introduction rule for
   845 solving continuity subgoals on terms with lambda abstractions.  In
   846 some rare cases the new simproc may fail to solve subgoals that the
   847 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   848 Potential INCOMPATIBILITY.
   849 
   850 * Command 'fixrec': specification syntax now conforms to the general
   851 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   852 examples.  INCOMPATIBILITY.
   853 
   854 
   855 *** ZF ***
   856 
   857 * Proof of Zorn's Lemma for partial orders.
   858 
   859 
   860 *** ML ***
   861 
   862 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   863 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   864 depends on multithreading, so timouts will not work before Poly/ML
   865 5.2.1!
   866 
   867 * High-level support for concurrent ML programming, see
   868 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   869 particularly convenient to organize independent functional
   870 computations.  The concept of "synchronized variables" provides a
   871 higher-order interface for components with shared state, avoiding the
   872 delicate details of mutexes and condition variables.  (Requires
   873 Poly/ML 5.2.1 or later.)
   874 
   875 * ML bindings produced via Isar commands are stored within the Isar
   876 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   877 become thread-safe and work with undo as expected (concerning
   878 top-level bindings, not side-effects on global references).
   879 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   880 compiler at runtime; really global bindings need to be given outside a
   881 theory.  (Requires Poly/ML 5.2 or later.)
   882 
   883 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   884 context.  Top-level ML bindings are stored within the proof context in
   885 a purely sequential fashion, disregarding the nested proof structure.
   886 ML bindings introduced by 'ML_prf' are discarded at the end of the
   887 proof.  (Requires Poly/ML 5.2 or later.)
   888 
   889 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   890 and Method.setup, as well as Isar commands 'attribute_setup' and
   891 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   892 existing code accordingly, or use plain 'setup' together with old
   893 Method.add_method.
   894 
   895 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   896 to 'a -> thm, while results are always tagged with an authentic oracle
   897 name.  The Isar command 'oracle' is now polymorphic, no argument type
   898 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   899 accordingly.  Note that extra performance may be gained by producing
   900 the cterm carefully, avoiding slow Thm.cterm_of.
   901 
   902 * Simplified interface for defining document antiquotations via
   903 ThyOutput.antiquotation, ThyOutput.output, and optionally
   904 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   905 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   906 examples.
   907 
   908 * More systematic treatment of long names, abstract name bindings, and
   909 name space operations.  Basic operations on qualified names have been
   910 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   911 Long_Name.append.  Old type bstring has been mostly replaced by
   912 abstract type binding (see structure Binding), which supports precise
   913 qualification by packages and local theory targets, as well as proper
   914 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   915 bstring values into Binding.name, or better pass through abstract
   916 bindings everywhere.  See further src/Pure/General/long_name.ML,
   917 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   918 
   919 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   920 LocalTheory.note etc.) now refer to the *full* internal name, not the
   921 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   922 
   923 * Disposed old type and term read functions (Sign.read_def_typ,
   924 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   925 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   926 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   927 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   928 resort for legacy applications.
   929 
   930 * Disposed old declarations, tactics, tactic combinators that refer to
   931 the simpset or claset of an implicit theory (such as Addsimps,
   932 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   933 embedded ML text, or local_simpset_of with a proper context passed as
   934 explicit runtime argument.
   935 
   936 * Rules and tactics that read instantiations (read_instantiate,
   937 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   938 context, which is required for parsing and type-checking.  Moreover,
   939 the variables are specified as plain indexnames, not string encodings
   940 thereof.  INCOMPATIBILITY.
   941 
   942 * Generic Toplevel.add_hook interface allows to analyze the result of
   943 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   944 for theorem dependency output of transactions resulting in a new
   945 theory state.
   946 
   947 * ML antiquotations: block-structured compilation context indicated by
   948 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   949 
   950   @{binding name}                         - basic name binding
   951   @{let ?pat = term}                      - term abbreviation (HO matching)
   952   @{note name = fact}                     - fact abbreviation
   953   @{thm fact}                             - singleton fact (with attributes)
   954   @{thms fact}                            - general fact (with attributes)
   955   @{lemma prop by method}                 - singleton goal
   956   @{lemma prop by meth1 meth2}            - singleton goal
   957   @{lemma prop1 ... propN by method}      - general goal
   958   @{lemma prop1 ... propN by meth1 meth2} - general goal
   959   @{lemma (open) ...}                     - open derivation
   960 
   961 
   962 *** System ***
   963 
   964 * The Isabelle "emacs" tool provides a specific interface to invoke
   965 Proof General / Emacs, with more explicit failure if that is not
   966 installed (the old isabelle-interface script silently falls back on
   967 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   968 installation location of the Proof General distribution.
   969 
   970 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   971 the Isabelle process into a JVM/Scala application.  See
   972 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   973 process wrapper has been discontinued.)
   974 
   975 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   976 
   977 * Various status messages (with exact source position information) are
   978 emitted, if proper markup print mode is enabled.  This allows
   979 user-interface components to provide detailed feedback on internal
   980 prover operations.
   981 
   982 
   983 
   984 New in Isabelle2008 (June 2008)
   985 -------------------------------
   986 
   987 *** General ***
   988 
   989 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   990 and updated, with formally checked references as hyperlinks.
   991 
   992 * Theory loader: use_thy (and similar operations) no longer set the
   993 implicit ML context, which was occasionally hard to predict and in
   994 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   995 provides a proper context already.
   996 
   997 * Theory loader: old-style ML proof scripts being *attached* to a thy
   998 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   999 'use' within a theory file will do the job.
  1000 
  1001 * Name space merge now observes canonical order, i.e. the second space
  1002 is inserted into the first one, while existing entries in the first
  1003 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1004 swap theory imports.
  1005 
  1006 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1007 INCOMPATIBILITY in identifier syntax etc.
  1008 
  1009 * Outer syntax: string tokens no longer admit escaped white space,
  1010 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1011 white space without escapes.
  1012 
  1013 * Outer syntax: string tokens may contain arbitrary character codes
  1014 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1015 "foo_bar".
  1016 
  1017 
  1018 *** Pure ***
  1019 
  1020 * Context-dependent token translations.  Default setup reverts locally
  1021 fixed variables, and adds hilite markup for undeclared frees.
  1022 
  1023 * Unused theorems can be found using the new command 'unused_thms'.
  1024 There are three ways of invoking it:
  1025 
  1026 (1) unused_thms
  1027      Only finds unused theorems in the current theory.
  1028 
  1029 (2) unused_thms thy_1 ... thy_n -
  1030      Finds unused theorems in the current theory and all of its ancestors,
  1031      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1032 
  1033 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1034      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1035      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1036      their ancestors.
  1037 
  1038 In order to increase the readability of the list produced by
  1039 unused_thms, theorems that have been created by a particular instance
  1040 of a theory command such as 'inductive' or 'function' are considered
  1041 to belong to the same "group", meaning that if at least one theorem in
  1042 this group is used, the other theorems in the same group are no longer
  1043 reported as unused.  Moreover, if all theorems in the group are
  1044 unused, only one theorem in the group is displayed.
  1045 
  1046 Note that proof objects have to be switched on in order for
  1047 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1048 usually the case when using Proof General with the default settings).
  1049 
  1050 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1051 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1052 duplicate fact bindings, or even accidental fact duplications.  Note
  1053 that tools may maintain dynamically scoped facts systematically, using
  1054 PureThy.add_thms_dynamic.
  1055 
  1056 * Command 'hide' now allows to hide from "fact" name space as well.
  1057 
  1058 * Eliminated destructive theorem database, simpset, claset, and
  1059 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1060 update of theories within ML code.
  1061 
  1062 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1063 INCOMPATIBILITY, object-logics depending on former Pure require
  1064 additional setup PureThy.old_appl_syntax_setup; object-logics
  1065 depending on former CPure need to refer to Pure.
  1066 
  1067 * Commands 'use' and 'ML' are now purely functional, operating on
  1068 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1069 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1070 INCOMPATIBILITY.
  1071 
  1072 * Command 'setup': discontinued implicit version with ML reference.
  1073 
  1074 * Instantiation target allows for simultaneous specification of class
  1075 instance operations together with an instantiation proof.
  1076 Type-checking phase allows to refer to class operations uniformly.
  1077 See src/HOL/Complex/Complex.thy for an Isar example and
  1078 src/HOL/Library/Eval.thy for an ML example.
  1079 
  1080 * Indexing of literal facts: be more serious about including only
  1081 facts from the visible specification/proof context, but not the
  1082 background context (locale etc.).  Affects `prop` notation and method
  1083 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1084 situations.
  1085 
  1086 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1087 "(open)" option, which used to expose internal bound variables to the
  1088 proof text.
  1089 
  1090 * Isar statements: removed obsolete case "rule_context".
  1091 INCOMPATIBILITY, better use explicit fixes/assumes.
  1092 
  1093 * Locale proofs: default proof step now includes 'unfold_locales';
  1094 hence 'proof' without argument may be used to unfold locale
  1095 predicates.
  1096 
  1097 
  1098 *** Document preparation ***
  1099 
  1100 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1101 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1102 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1103 spot); renamed link color from "darkblue" to "linkcolor" (default
  1104 value unchanged, can be redefined via \definecolor); no longer sets
  1105 "a4paper" option (unnecessary or even intrusive).
  1106 
  1107 * Antiquotation @{lemma A method} proves proposition A by the given
  1108 method (either a method name or a method name plus (optional) method
  1109 arguments in parentheses) and prints A just like @{prop A}.
  1110 
  1111 
  1112 *** HOL ***
  1113 
  1114 * New primrec package.  Specification syntax conforms in style to
  1115 definition/function/....  No separate induction rule is provided.  The
  1116 "primrec" command distinguishes old-style and new-style specifications
  1117 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1118 When adjusting theories, beware: constants stemming from new-style
  1119 primrec specifications have authentic syntax.
  1120 
  1121 * Metis prover is now an order of magnitude faster, and also works
  1122 with multithreading.
  1123 
  1124 * Metis: the maximum number of clauses that can be produced from a
  1125 theorem is now given by the attribute max_clauses.  Theorems that
  1126 exceed this number are ignored, with a warning printed.
  1127 
  1128 * Sledgehammer no longer produces structured proofs by default. To
  1129 enable, declare [[sledgehammer_full = true]].  Attributes
  1130 reconstruction_modulus, reconstruction_sorts renamed
  1131 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1132 
  1133 * Method "induct_scheme" derives user-specified induction rules
  1134 from well-founded induction and completeness of patterns. This factors
  1135 out some operations that are done internally by the function package
  1136 and makes them available separately.  See
  1137 src/HOL/ex/Induction_Scheme.thy for examples.
  1138 
  1139 * More flexible generation of measure functions for termination
  1140 proofs: Measure functions can be declared by proving a rule of the
  1141 form "is_measure f" and giving it the [measure_function] attribute.
  1142 The "is_measure" predicate is logically meaningless (always true), and
  1143 just guides the heuristic.  To find suitable measure functions, the
  1144 termination prover sets up the goal "is_measure ?f" of the appropriate
  1145 type and generates all solutions by prolog-style backwards proof using
  1146 the declared rules.
  1147 
  1148 This setup also deals with rules like 
  1149 
  1150   "is_measure f ==> is_measure (list_size f)"
  1151 
  1152 which accommodates nested datatypes that recurse through lists.
  1153 Similar rules are predeclared for products and option types.
  1154 
  1155 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1156 
  1157   INCOMPATIBILITIES:
  1158 
  1159   - Definitions of overloaded constants on sets have to be replaced by
  1160     definitions on => and bool.
  1161 
  1162   - Some definitions of overloaded operators on sets can now be proved
  1163     using the definitions of the operators on => and bool.  Therefore,
  1164     the following theorems have been renamed:
  1165 
  1166       subset_def   -> subset_eq
  1167       psubset_def  -> psubset_eq
  1168       set_diff_def -> set_diff_eq
  1169       Compl_def    -> Compl_eq
  1170       Sup_set_def  -> Sup_set_eq
  1171       Inf_set_def  -> Inf_set_eq
  1172       sup_set_def  -> sup_set_eq
  1173       inf_set_def  -> inf_set_eq
  1174 
  1175   - Due to the incompleteness of the HO unification algorithm, some
  1176     rules such as subst may require manual instantiation, if some of
  1177     the unknowns in the rule is a set.
  1178 
  1179   - Higher order unification and forward proofs:
  1180     The proof pattern
  1181 
  1182       have "P (S::'a set)" <...>
  1183       then have "EX S. P S" ..
  1184 
  1185     no longer works (due to the incompleteness of the HO unification
  1186     algorithm) and must be replaced by the pattern
  1187 
  1188       have "EX S. P S"
  1189       proof
  1190         show "P S" <...>
  1191       qed
  1192 
  1193   - Calculational reasoning with subst (or similar rules):
  1194     The proof pattern
  1195 
  1196       have "P (S::'a set)" <...>
  1197       also have "S = T" <...>
  1198       finally have "P T" .
  1199 
  1200     no longer works (for similar reasons as the previous example) and
  1201     must be replaced by something like
  1202 
  1203       have "P (S::'a set)" <...>
  1204       moreover have "S = T" <...>
  1205       ultimately have "P T" by simp
  1206 
  1207   - Tactics or packages written in ML code:
  1208     Code performing pattern matching on types via
  1209 
  1210       Type ("set", [T]) => ...
  1211 
  1212     must be rewritten. Moreover, functions like strip_type or
  1213     binder_types no longer return the right value when applied to a
  1214     type of the form
  1215 
  1216       T1 => ... => Tn => U => bool
  1217 
  1218     rather than
  1219 
  1220       T1 => ... => Tn => U set
  1221 
  1222 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1223 Wellfounded_Relations to theory Wellfounded.
  1224 
  1225 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1226 
  1227 * Class finite no longer treats UNIV as class parameter.  Use class
  1228 enum from theory Library/Enum instead to achieve a similar effect.
  1229 INCOMPATIBILITY.
  1230 
  1231 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1232 and "Cons".  INCOMPATIBILITY.
  1233 
  1234 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1235 Potential INCOMPATIBILITY.
  1236 
  1237 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1238 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1239 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1240 
  1241 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1242 the same name in theory Orderings:
  1243 
  1244   less_trans
  1245   less_linear
  1246   le_imp_less_or_eq
  1247   le_less_trans
  1248   less_le_trans
  1249   less_not_sym
  1250   less_asym
  1251 
  1252 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1253 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1254 and different variable names.
  1255 
  1256 * Library/Option_ord.thy: Canonical order on option type.
  1257 
  1258 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1259 finite maps.
  1260 
  1261 * Library/Countable.thy: Type class for countable types.
  1262 
  1263 * Theory Int: The representation of numerals has changed.  The infix
  1264 operator BIT and the bit datatype with constructors B0 and B1 have
  1265 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1266 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1267 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1268 accordingly.
  1269 
  1270 * Theory Nat: definition of <= and < on natural numbers no longer
  1271 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1272 le_def and less_def have disappeared.  Consider lemmas not_less
  1273 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1274 
  1275 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1276 (whose purpose mainly is for various fold_set functionals) have been
  1277 abandoned in favor of the existing algebraic classes
  1278 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1279 lower_semilattice (resp. upper_semilattice) and linorder.
  1280 INCOMPATIBILITY.
  1281 
  1282 * Theory Transitive_Closure: induct and cases rules now declare proper
  1283 case_names ("base" and "step").  INCOMPATIBILITY.
  1284 
  1285 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1286 lattices.  The form set-specific version is available as
  1287 Inductive.lfp_ordinal_induct_set.
  1288 
  1289 * Renamed theorems "power.simps" to "power_int.simps".
  1290 INCOMPATIBILITY.
  1291 
  1292 * Class semiring_div provides basic abstract properties of semirings
  1293 with division and modulo operations.  Subsumes former class dvd_mod.
  1294 
  1295 * Merged theories IntDef, Numeral and IntArith into unified theory
  1296 Int.  INCOMPATIBILITY.
  1297 
  1298 * Theory Library/Code_Index: type "index" now represents natural
  1299 numbers rather than integers.  INCOMPATIBILITY.
  1300 
  1301 * New class "uminus" with operation "uminus" (split of from class
  1302 "minus" which now only has operation "minus", binary).
  1303 INCOMPATIBILITY.
  1304 
  1305 * Constants "card", "internal_split", "option_map" now with authentic
  1306 syntax.  INCOMPATIBILITY.
  1307 
  1308 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1309 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1310 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1311 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1312 Sup_set_def, le_def, less_def, option_map_def now with object
  1313 equality.  INCOMPATIBILITY.
  1314 
  1315 * Records. Removed K_record, and replaced it by pure lambda term
  1316 %x. c. The simplifier setup is now more robust against eta expansion.
  1317 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1318 
  1319 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1320 
  1321 * Library/ListVector: new theory of arithmetic vector operations.
  1322 
  1323 * Library/Order_Relation: new theory of various orderings as sets of
  1324 pairs.  Defines preorders, partial orders, linear orders and
  1325 well-orders on sets and on types.
  1326 
  1327 
  1328 *** ZF ***
  1329 
  1330 * Renamed some theories to allow to loading both ZF and HOL in the
  1331 same session:
  1332 
  1333   Datatype  -> Datatype_ZF
  1334   Inductive -> Inductive_ZF
  1335   Int       -> Int_ZF
  1336   IntDiv    -> IntDiv_ZF
  1337   Nat       -> Nat_ZF
  1338   List      -> List_ZF
  1339   Main      -> Main_ZF
  1340 
  1341 INCOMPATIBILITY: ZF theories that import individual theories below
  1342 Main might need to be adapted.  Regular theory Main is still
  1343 available, as trivial extension of Main_ZF.
  1344 
  1345 
  1346 *** ML ***
  1347 
  1348 * ML within Isar: antiquotation @{const name} or @{const
  1349 name(typargs)} produces statically-checked Const term.
  1350 
  1351 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1352 (of the same name).  Removed obsolete print command.
  1353 
  1354 * Removed obsolete "use_legacy_bindings" function.
  1355 
  1356 * The ``print mode'' is now a thread-local value derived from a global
  1357 template (the former print_mode reference), thus access becomes
  1358 non-critical.  The global print_mode reference is for session
  1359 management only; user-code should use print_mode_value,
  1360 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1361 
  1362 * Functions system/system_out provide a robust way to invoke external
  1363 shell commands, with propagation of interrupts (requires Poly/ML
  1364 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1365 
  1366 
  1367 *** System ***
  1368 
  1369 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1370 in accordance with Proof General 3.7, which prefers GNU emacs.
  1371 
  1372 * isatool tty runs Isabelle process with plain tty interaction;
  1373 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1374 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1375 
  1376 * isatool browser now works with Cygwin as well, using general
  1377 "javapath" function defined in Isabelle process environment.
  1378 
  1379 * YXML notation provides a simple and efficient alternative to
  1380 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1381 isatool yxml as described in the Isabelle system manual.
  1382 
  1383 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1384 provides general wrapper for managing an Isabelle process in a robust
  1385 fashion, with ``cooked'' output from stdin/stderr.
  1386 
  1387 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1388 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1389 
  1390 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1391 way of changing the user's settings is via
  1392 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1393 script.
  1394 
  1395 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1396 cores of the underlying machine, which is a good starting point for
  1397 optimal performance tuning.  The corresponding usedir option -M allows
  1398 "max" as an alias for "0".  WARNING: does not work on certain versions
  1399 of Mac OS (with Poly/ML 5.1).
  1400 
  1401 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1402 adverse effect of Isabelle flooding interactive front-ends (notably
  1403 ProofGeneral / XEmacs).
  1404 
  1405 
  1406 
  1407 New in Isabelle2007 (November 2007)
  1408 -----------------------------------
  1409 
  1410 *** General ***
  1411 
  1412 * More uniform information about legacy features, notably a
  1413 warning/error of "Legacy feature: ...", depending on the state of the
  1414 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1415 legacy features will disappear eventually.
  1416 
  1417 * Theory syntax: the header format ``theory A = B + C:'' has been
  1418 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1419 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1420 
  1421 * Theory syntax: the old non-Isar theory file format has been
  1422 discontinued altogether.  Note that ML proof scripts may still be used
  1423 with Isar theories; migration is usually quite simple with the ML
  1424 function use_legacy_bindings.  INCOMPATIBILITY.
  1425 
  1426 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1427 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1428 quotes.
  1429 
  1430 * Theory loader: be more serious about observing the static theory
  1431 header specifications (including optional directories), but not the
  1432 accidental file locations of previously successful loads.  The strict
  1433 update policy of former update_thy is now already performed by
  1434 use_thy, so the former has been removed; use_thys updates several
  1435 theories simultaneously, just as 'imports' within a theory header
  1436 specification, but without merging the results.  Potential
  1437 INCOMPATIBILITY: may need to refine theory headers and commands
  1438 ROOT.ML which depend on load order.
  1439 
  1440 * Theory loader: optional support for content-based file
  1441 identification, instead of the traditional scheme of full physical
  1442 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1443 (cf. the system manual).  The new scheme allows to work with
  1444 non-finished theories in persistent session images, such that source
  1445 files may be moved later on without requiring reloads.
  1446 
  1447 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1448 file (with the same base name as the theory) are considered a legacy
  1449 feature, which will disappear eventually. Even now, the theory loader
  1450 no longer maintains dependencies on such files.
  1451 
  1452 * Syntax: the scope for resolving ambiguities via type-inference is
  1453 now limited to individual terms, instead of whole simultaneous
  1454 specifications as before. This greatly reduces the complexity of the
  1455 syntax module and improves flexibility by separating parsing and
  1456 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1457 'fixes' etc.) are required in rare situations.
  1458 
  1459 * Syntax: constants introduced by new-style packages ('definition',
  1460 'abbreviation' etc.) are passed through the syntax module in
  1461 ``authentic mode''. This means that associated mixfix annotations
  1462 really stick to such constants, independently of potential name space
  1463 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1464 trees are represented slightly differently, may need to adapt syntax
  1465 translations accordingly. Use CONST marker in 'translations' and
  1466 @{const_syntax} antiquotation in 'parse_translation' etc.
  1467 
  1468 * Legacy goal package: reduced interface to the bare minimum required
  1469 to keep existing proof scripts running.  Most other user-level
  1470 functions are now part of the OldGoals structure, which is *not* open
  1471 by default (consider isatool expandshort before open OldGoals).
  1472 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1473 these tend to cause confusion about the actual goal (!) context being
  1474 used here, which is not necessarily the same as the_context().
  1475 
  1476 * Command 'find_theorems': supports "*" wild-card in "name:"
  1477 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1478 support a specific search form (see ProofGeneral/CHANGES).
  1479 
  1480 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1481 by default, which means that "prems" (and also "fixed variables") are
  1482 suppressed from proof state output.  Note that the ProofGeneral
  1483 settings mechanism allows to change and save options persistently, but
  1484 older versions of Isabelle will fail to start up if a negative prems
  1485 limit is imposed.
  1486 
  1487 * Local theory targets may be specified by non-nested blocks of
  1488 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1489 contain definitions, theorems etc., including any derived mechanism
  1490 that has been implemented on top of these primitives.  This concept
  1491 generalizes the existing ``theorem (in ...)'' towards more versatility
  1492 and scalability.
  1493 
  1494 * Proof General interface: proper undo of final 'end' command;
  1495 discontinued Isabelle/classic mode (ML proof scripts).
  1496 
  1497 
  1498 *** Document preparation ***
  1499 
  1500 * Added antiquotation @{theory name} which prints the given name,
  1501 after checking that it refers to a valid ancestor theory in the
  1502 current context.
  1503 
  1504 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1505 check the given source text as ML type/structure, printing verbatim.
  1506 
  1507 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1508 "c args == rhs" given in the current context.  (Any number of
  1509 arguments may be given on the LHS.)
  1510 
  1511 
  1512 *** Pure ***
  1513 
  1514 * The 'class' package offers a combination of axclass and locale to
  1515 achieve Haskell-like type classes in Isabelle.  Definitions and
  1516 theorems within a class context produce both relative results (with
  1517 implicit parameters according to the locale context), and polymorphic
  1518 constants with qualified polymorphism (according to the class
  1519 context).  Within the body context of a 'class' target, a separate
  1520 syntax layer ("user space type system") takes care of converting
  1521 between global polymorphic consts and internal locale representation.
  1522 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1523 "isatool doc classes" provides a tutorial.
  1524 
  1525 * Generic code generator framework allows to generate executable
  1526 code for ML and Haskell (including Isabelle classes).  A short usage
  1527 sketch:
  1528 
  1529     internal compilation:
  1530         export_code <list of constants (term syntax)> in SML
  1531     writing SML code to a file:
  1532         export_code <list of constants (term syntax)> in SML <filename>
  1533     writing OCaml code to a file:
  1534         export_code <list of constants (term syntax)> in OCaml <filename>
  1535     writing Haskell code to a bunch of files:
  1536         export_code <list of constants (term syntax)> in Haskell <filename>
  1537 
  1538     evaluating closed propositions to True/False using code generation:
  1539         method ``eval''
  1540 
  1541 Reasonable default setup of framework in HOL.
  1542 
  1543 Theorem attributs for selecting and transforming function equations theorems:
  1544 
  1545     [code fun]:        select a theorem as function equation for a specific constant
  1546     [code fun del]:    deselect a theorem as function equation for a specific constant
  1547     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1548     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1549 
  1550 User-defined serializations (target in {SML, OCaml, Haskell}):
  1551 
  1552     code_const <and-list of constants (term syntax)>
  1553       {(target) <and-list of const target syntax>}+
  1554 
  1555     code_type <and-list of type constructors>
  1556       {(target) <and-list of type target syntax>}+
  1557 
  1558     code_instance <and-list of instances>
  1559       {(target)}+
  1560         where instance ::= <type constructor> :: <class>
  1561 
  1562     code_class <and_list of classes>
  1563       {(target) <and-list of class target syntax>}+
  1564         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1565 
  1566 code_instance and code_class only are effective to target Haskell.
  1567 
  1568 For example usage see src/HOL/ex/Codegenerator.thy and
  1569 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1570 generation from Isabelle/HOL theories is available via "isatool doc
  1571 codegen".
  1572 
  1573 * Code generator: consts in 'consts_code' Isar commands are now
  1574 referred to by usual term syntax (including optional type
  1575 annotations).
  1576 
  1577 * Command 'no_translations' removes translation rules from theory
  1578 syntax.
  1579 
  1580 * Overloaded definitions are now actually checked for acyclic
  1581 dependencies.  The overloading scheme is slightly more general than
  1582 that of Haskell98, although Isabelle does not demand an exact
  1583 correspondence to type class and instance declarations.
  1584 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1585 exotic versions of overloading -- at the discretion of the user!
  1586 
  1587 Polymorphic constants are represented via type arguments, i.e. the
  1588 instantiation that matches an instance against the most general
  1589 declaration given in the signature.  For example, with the declaration
  1590 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1591 as c(nat).  Overloading is essentially simultaneous structural
  1592 recursion over such type arguments.  Incomplete specification patterns
  1593 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1594 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1595 Command 'print_theory' outputs the normalized system of recursive
  1596 equations, see section "definitions".
  1597 
  1598 * Configuration options are maintained within the theory or proof
  1599 context (with name and type bool/int/string), providing a very simple
  1600 interface to a poor-man's version of general context data.  Tools may
  1601 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1602 these values using Config.get etc.  Users may change options via an
  1603 associated attribute of the same name.  This form of context
  1604 declaration works particularly well with commands 'declare' or
  1605 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1606 very easy to avoid global references, which would not observe Isar
  1607 toplevel undo/redo and fail to work with multithreading.
  1608 
  1609 Various global ML references of Pure and HOL have been turned into
  1610 configuration options:
  1611 
  1612   Unify.search_bound		unify_search_bound
  1613   Unify.trace_bound		unify_trace_bound
  1614   Unify.trace_simp		unify_trace_simp
  1615   Unify.trace_types		unify_trace_types
  1616   Simplifier.simp_depth_limit	simp_depth_limit
  1617   Blast.depth_limit		blast_depth_limit
  1618   DatatypeProp.dtK		datatype_distinctness_limit
  1619   fast_arith_neq_limit  	fast_arith_neq_limit
  1620   fast_arith_split_limit	fast_arith_split_limit
  1621 
  1622 * Named collections of theorems may be easily installed as context
  1623 data using the functor NamedThmsFun (see also
  1624 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1625 attributes; there is also a toplevel print command.  This facility is
  1626 just a common case of general context data, which is the preferred way
  1627 for anything more complex than just a list of facts in canonical
  1628 order.
  1629 
  1630 * Isar: command 'declaration' augments a local theory by generic
  1631 declaration functions written in ML.  This enables arbitrary content
  1632 being added to the context, depending on a morphism that tells the
  1633 difference of the original declaration context wrt. the application
  1634 context encountered later on.
  1635 
  1636 * Isar: proper interfaces for simplification procedures.  Command
  1637 'simproc_setup' declares named simprocs (with match patterns, and body
  1638 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1639 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1640 
  1641 * Isar: an extra pair of brackets around attribute declarations
  1642 abbreviates a theorem reference involving an internal dummy fact,
  1643 which will be ignored later --- only the effect of the attribute on
  1644 the background context will persist.  This form of in-place
  1645 declarations is particularly useful with commands like 'declare' and
  1646 'using', for example ``have A using [[simproc a]] by simp''.
  1647 
  1648 * Isar: method "assumption" (and implicit closing of subproofs) now
  1649 takes simple non-atomic goal assumptions into account: after applying
  1650 an assumption as a rule the resulting subgoals are solved by atomic
  1651 assumption steps.  This is particularly useful to finish 'obtain'
  1652 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1653 without referring to the original premise "!!x. P x ==> thesis" in the
  1654 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1655 more permissive.
  1656 
  1657 * Isar: implicit use of prems from the Isar proof context is
  1658 considered a legacy feature.  Common applications like ``have A .''
  1659 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1660 referencing facts explicitly here improves readability and
  1661 maintainability of proof texts.
  1662 
  1663 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1664 the obtained context from the course of reasoning!  For example:
  1665 
  1666   assume "EX x y. A x & B y"   -- "any previous fact"
  1667   then guess x and y by clarify
  1668 
  1669 This technique is potentially adventurous, depending on the facts and
  1670 proof tools being involved here.
  1671 
  1672 * Isar: known facts from the proof context may be specified as literal
  1673 propositions, using ASCII back-quote syntax.  This works wherever
  1674 named facts used to be allowed so far, in proof commands, proof
  1675 methods, attributes etc.  Literal facts are retrieved from the context
  1676 according to unification of type and term parameters.  For example,
  1677 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1678 theorems in the current context, then these are valid literal facts:
  1679 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1680 
  1681 There is also a proof method "fact" which does the same composition
  1682 for explicit goal states, e.g. the following proof texts coincide with
  1683 certain special cases of literal facts:
  1684 
  1685   have "A" by fact                 ==  note `A`
  1686   have "A ==> B" by fact           ==  note `A ==> B`
  1687   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1688   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1689 
  1690 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1691 outer syntax.  Thus symbolic identifiers may be used without
  1692 additional white space in declarations like this: ``assume *: A''.
  1693 
  1694 * Isar: 'print_facts' prints all local facts of the current context,
  1695 both named and unnamed ones.
  1696 
  1697 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1698 
  1699   def x == "t" and y == "u"
  1700 
  1701 * Isar: added command 'unfolding', which is structurally similar to
  1702 'using', but affects both the goal state and facts by unfolding given
  1703 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1704 'unfolded' attribute may be replaced by first-class proof text.
  1705 
  1706 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1707 and command 'unfolding' now all support object-level equalities
  1708 (potentially conditional).  The underlying notion of rewrite rule is
  1709 analogous to the 'rule_format' attribute, but *not* that of the
  1710 Simplifier (which is usually more generous).
  1711 
  1712 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1713 premises of a theorem by n. Useful in conjunction with drule.
  1714 
  1715 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1716 method expression within a sandbox consisting of the first N
  1717 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1718 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1719 simplifies all new goals that emerge from applying rule foo to the
  1720 originally first one.
  1721 
  1722 * Isar: schematic goals are no longer restricted to higher-order
  1723 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1724 expected.
  1725 
  1726 * Isar: the conclusion of a long theorem statement is now either
  1727 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1728 (essentially a disjunction of cases with local parameters and
  1729 assumptions).  The latter allows to express general elimination rules
  1730 adequately; in this notation common elimination rules look like this:
  1731 
  1732   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1733     assumes "EX x. P x"
  1734     obtains x where "P x"
  1735 
  1736   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1737     assumes "A & B"
  1738     obtains A and B
  1739 
  1740   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1741     assumes "A | B"
  1742     obtains
  1743       A
  1744     | B
  1745 
  1746 The subsequent classical rules even refer to the formal "thesis"
  1747 explicitly:
  1748 
  1749   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1750     obtains "~ thesis"
  1751 
  1752   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1753     obtains "thesis ==> something"
  1754 
  1755 The actual proof of an 'obtains' statement is analogous to that of the
  1756 Isar proof element 'obtain', only that there may be several cases.
  1757 Optional case names may be specified in parentheses; these will be
  1758 available both in the present proof and as annotations in the
  1759 resulting rule, for later use with the 'cases' method (cf. attribute
  1760 case_names).
  1761 
  1762 * Isar: the assumptions of a long theorem statement are available as
  1763 "assms" fact in the proof context.  This is more appropriate than the
  1764 (historical) "prems", which refers to all assumptions of the current
  1765 context, including those from the target locale, proof body etc.
  1766 
  1767 * Isar: 'print_statement' prints theorems from the current theory or
  1768 proof context in long statement form, according to the syntax of a
  1769 top-level lemma.
  1770 
  1771 * Isar: 'obtain' takes an optional case name for the local context
  1772 introduction rule (default "that").
  1773 
  1774 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1775 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1776 to occur.
  1777 
  1778 * Pure: syntax "CONST name" produces a fully internalized constant
  1779 according to the current context.  This is particularly useful for
  1780 syntax translations that should refer to internal constant
  1781 representations independently of name spaces.
  1782 
  1783 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1784 instead of "FOO ". This allows multiple binder declarations to coexist
  1785 in the same context.  INCOMPATIBILITY.
  1786 
  1787 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1788 primitive that also works in a locale context (both for constants and
  1789 fixed variables). Type declaration and internal syntactic representation
  1790 of given constants retrieved from the context. Likewise, the
  1791 'no_notation' command allows to remove given syntax annotations from the
  1792 current context.
  1793 
  1794 * Isar/locales: new derived specification elements 'axiomatization',
  1795 'definition', 'abbreviation', which support type-inference, admit
  1796 object-level specifications (equality, equivalence).  See also the
  1797 isar-ref manual.  Examples:
  1798 
  1799   axiomatization
  1800     eq  (infix "===" 50) where
  1801     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1802 
  1803   definition "f x y = x + y + 1"
  1804   definition g where "g x = f x x"
  1805 
  1806   abbreviation
  1807     neq  (infix "=!=" 50) where
  1808     "x =!= y == ~ (x === y)"
  1809 
  1810 These specifications may be also used in a locale context.  Then the
  1811 constants being introduced depend on certain fixed parameters, and the
  1812 constant name is qualified by the locale base name.  An internal
  1813 abbreviation takes care for convenient input and output, making the
  1814 parameters implicit and using the original short name.  See also
  1815 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1816 entities from a monomorphic theory.
  1817 
  1818 Presently, abbreviations are only available 'in' a target locale, but
  1819 not inherited by general import expressions.  Also note that
  1820 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1821 'translations' in common applications.  The "no_abbrevs" print mode
  1822 prevents folding of abbreviations in term output.
  1823 
  1824 Concrete syntax is attached to specified constants in internal form,
  1825 independently of name spaces.  The parse tree representation is
  1826 slightly different -- use 'notation' instead of raw 'syntax', and
  1827 'translations' with explicit "CONST" markup to accommodate this.
  1828 
  1829 * Pure/Isar: unified syntax for new-style specification mechanisms
  1830 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1831 full type inference and dummy patterns ("_").  For example:
  1832 
  1833   definition "K x _ = x"
  1834 
  1835   inductive conj for A B
  1836   where "A ==> B ==> conj A B"
  1837 
  1838 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1839 the current context.  Print mode "no_abbrevs" prevents inversion of
  1840 abbreviations on output.
  1841 
  1842 * Isar/locales: improved parameter handling: use of locales "var" and
  1843 "struct" no longer necessary; - parameter renamings are no longer
  1844 required to be injective.  For example, this allows to define
  1845 endomorphisms as locale endom = homom mult mult h.
  1846 
  1847 * Isar/locales: changed the way locales with predicates are defined.
  1848 Instead of accumulating the specification, the imported expression is
  1849 now an interpretation.  INCOMPATIBILITY: different normal form of
  1850 locale expressions.  In particular, in interpretations of locales with
  1851 predicates, goals repesenting already interpreted fragments are not
  1852 removed automatically.  Use methods `intro_locales' and
  1853 `unfold_locales'; see below.
  1854 
  1855 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1856 provide backward reasoning on locales predicates.  The methods are
  1857 aware of interpretations and discharge corresponding goals.
  1858 `intro_locales' is less aggressive then `unfold_locales' and does not
  1859 unfold predicates to assumptions.
  1860 
  1861 * Isar/locales: the order in which locale fragments are accumulated
  1862 has changed.  This enables to override declarations from fragments due
  1863 to interpretations -- for example, unwanted simp rules.
  1864 
  1865 * Isar/locales: interpretation in theories and proof contexts has been
  1866 extended.  One may now specify (and prove) equations, which are
  1867 unfolded in interpreted theorems.  This is useful for replacing
  1868 defined concepts (constants depending on locale parameters) by
  1869 concepts already existing in the target context.  Example:
  1870 
  1871   interpretation partial_order ["op <= :: [int, int] => bool"]
  1872     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1873 
  1874 Typically, the constant `partial_order.less' is created by a
  1875 definition specification element in the context of locale
  1876 partial_order.
  1877 
  1878 * Method "induct": improved internal context management to support
  1879 local fixes and defines on-the-fly. Thus explicit meta-level
  1880 connectives !!  and ==> are rarely required anymore in inductive goals
  1881 (using object-logic connectives for this purpose has been long
  1882 obsolete anyway). Common proof patterns are explained in
  1883 src/HOL/Induct/Common_Patterns.thy, see also
  1884 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1885 examples.
  1886 
  1887 * Method "induct": improved handling of simultaneous goals. Instead of
  1888 introducing object-level conjunction, the statement is now split into
  1889 several conclusions, while the corresponding symbolic cases are nested
  1890 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1891 see src/HOL/Induct/Common_Patterns.thy, for example.
  1892 
  1893 * Method "induct": mutual induction rules are now specified as a list
  1894 of rule sharing the same induction cases. HOL packages usually provide
  1895 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1896 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1897 mutual induction rules differently, i.e. like this:
  1898 
  1899   (induct rule: foo_bar.inducts)
  1900   (induct set: foo bar)
  1901   (induct pred: foo bar)
  1902   (induct type: foo bar)
  1903 
  1904 The ML function ProjectRule.projections turns old-style rules into the
  1905 new format.
  1906 
  1907 * Method "coinduct": dual of induction, see
  1908 src/HOL/Library/Coinductive_List.thy for various examples.
  1909 
  1910 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1911 considered a legacy feature.
  1912 
  1913 * Attribute "symmetric" produces result with standardized schematic
  1914 variables (index 0).  Potential INCOMPATIBILITY.
  1915 
  1916 * Simplifier: by default the simplifier trace only shows top level
  1917 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1918 default. Thus there is less danger of being flooded by the trace. The
  1919 trace indicates where parts have been suppressed.
  1920   
  1921 * Provers/classical: removed obsolete classical version of elim_format
  1922 attribute; classical elim/dest rules are now treated uniformly when
  1923 manipulating the claset.
  1924 
  1925 * Provers/classical: stricter checks to ensure that supplied intro,
  1926 dest and elim rules are well-formed; dest and elim rules must have at
  1927 least one premise.
  1928 
  1929 * Provers/classical: attributes dest/elim/intro take an optional
  1930 weight argument for the rule (just as the Pure versions).  Weights are
  1931 ignored by automated tools, but determine the search order of single
  1932 rule steps.
  1933 
  1934 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1935 where the body does not mention the bound variable.  Note that dummy
  1936 patterns implicitly depend on their context of bounds, which makes
  1937 "{_. _}" match any set comprehension as expected.  Potential
  1938 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1939 constant "_idtdummy" in the binding position.
  1940 
  1941 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1942 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1943 for example "A -> B" => "Pi A (%_. B)".
  1944 
  1945 * Pure: 'class_deps' command visualizes the subclass relation, using
  1946 the graph browser tool.
  1947 
  1948 * Pure: 'print_theory' now suppresses certain internal declarations by
  1949 default; use '!' option for full details.
  1950 
  1951 
  1952 *** HOL ***
  1953 
  1954 * Method "metis" proves goals by applying the Metis general-purpose
  1955 resolution prover (see also http://gilith.com/software/metis/).
  1956 Examples are in the directory MetisExamples.  WARNING: the
  1957 Isabelle/HOL-Metis integration does not yet work properly with
  1958 multi-threading.
  1959   
  1960 * Command 'sledgehammer' invokes external automatic theorem provers as
  1961 background processes.  It generates calls to the "metis" method if
  1962 successful. These can be pasted into the proof.  Users do not have to
  1963 wait for the automatic provers to return.  WARNING: does not really
  1964 work with multi-threading.
  1965 
  1966 * New "auto_quickcheck" feature tests outermost goal statements for
  1967 potential counter-examples.  Controlled by ML references
  1968 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1969 5000 milliseconds).  Fails silently if statements is outside of
  1970 executable fragment, or any other codgenerator problem occurs.
  1971 
  1972 * New constant "undefined" with axiom "undefined x = undefined".
  1973 
  1974 * Added class "HOL.eq", allowing for code generation with polymorphic
  1975 equality.
  1976 
  1977 * Some renaming of class constants due to canonical name prefixing in
  1978 the new 'class' package:
  1979 
  1980     HOL.abs ~> HOL.abs_class.abs
  1981     HOL.divide ~> HOL.divide_class.divide
  1982     0 ~> HOL.zero_class.zero
  1983     1 ~> HOL.one_class.one
  1984     op + ~> HOL.plus_class.plus
  1985     op - ~> HOL.minus_class.minus
  1986     uminus ~> HOL.minus_class.uminus
  1987     op * ~> HOL.times_class.times
  1988     op < ~> HOL.ord_class.less
  1989     op <= > HOL.ord_class.less_eq
  1990     Nat.power ~> Power.power_class.power
  1991     Nat.size ~> Nat.size_class.size
  1992     Numeral.number_of ~> Numeral.number_class.number_of
  1993     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1994     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1995     Orderings.min ~> Orderings.ord_class.min
  1996     Orderings.max ~> Orderings.ord_class.max
  1997     Divides.op div ~> Divides.div_class.div
  1998     Divides.op mod ~> Divides.div_class.mod
  1999     Divides.op dvd ~> Divides.div_class.dvd
  2000 
  2001 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2002 
  2003 a) User-defined constants using any of the names "plus", "minus",
  2004 "times", "less" or "less_eq". The standard syntax translations for
  2005 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2006 names.
  2007 
  2008 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2009 INCOMPATIBILITY: use more specific names.
  2010 
  2011 c) Permutative equations (e.g. "a + b = b + a")
  2012 Since the change of names also changes the order of terms, permutative
  2013 rewrite rules may get applied in a different order. Experience shows
  2014 that this is rarely the case (only two adaptions in the whole Isabelle
  2015 distribution).  INCOMPATIBILITY: rewrite proofs
  2016 
  2017 d) ML code directly refering to constant names
  2018 This in general only affects hand-written proof tactics, simprocs and
  2019 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2020 Consider using @{const_name} antiquotation.
  2021 
  2022 * New class "default" with associated constant "default".
  2023 
  2024 * Function "sgn" is now overloaded and available on int, real, complex
  2025 (and other numeric types), using class "sgn".  Two possible defs of
  2026 sgn are given as equational assumptions in the classes sgn_if and
  2027 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2028 INCOMPATIBILITY.
  2029 
  2030 * Locale "partial_order" now unified with class "order" (cf. theory
  2031 Orderings), added parameter "less".  INCOMPATIBILITY.
  2032 
  2033 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2034 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2035 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2036 
  2037 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2038 changed order of proof goals in instance proofs.
  2039 
  2040 * The transitivity reasoner for partial and linear orders is set up
  2041 for classes "order" and "linorder".  Instances of the reasoner are available
  2042 in all contexts importing or interpreting the corresponding locales.
  2043 Method "order" invokes the reasoner separately; the reasoner
  2044 is also integrated with the Simplifier as a solver.  Diagnostic
  2045 command 'print_orders' shows the available instances of the reasoner
  2046 in the current context.
  2047 
  2048 * Localized monotonicity predicate in theory "Orderings"; integrated
  2049 lemmas max_of_mono and min_of_mono with this predicate.
  2050 INCOMPATIBILITY.
  2051 
  2052 * Formulation of theorem "dense" changed slightly due to integration
  2053 with new class dense_linear_order.
  2054 
  2055 * Uniform lattice theory development in HOL.
  2056 
  2057     constants "meet" and "join" now named "inf" and "sup"
  2058     constant "Meet" now named "Inf"
  2059 
  2060     classes "meet_semilorder" and "join_semilorder" now named
  2061       "lower_semilattice" and "upper_semilattice"
  2062     class "lorder" now named "lattice"
  2063     class "comp_lat" now named "complete_lattice"
  2064 
  2065     Instantiation of lattice classes allows explicit definitions
  2066     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2067 
  2068   INCOMPATIBILITY.  Theorem renames:
  2069 
  2070     meet_left_le            ~> inf_le1
  2071     meet_right_le           ~> inf_le2
  2072     join_left_le            ~> sup_ge1
  2073     join_right_le           ~> sup_ge2
  2074     meet_join_le            ~> inf_sup_ord
  2075     le_meetI                ~> le_infI
  2076     join_leI                ~> le_supI
  2077     le_meet                 ~> le_inf_iff
  2078     le_join                 ~> ge_sup_conv
  2079     meet_idempotent         ~> inf_idem
  2080     join_idempotent         ~> sup_idem
  2081     meet_comm               ~> inf_commute
  2082     join_comm               ~> sup_commute
  2083     meet_leI1               ~> le_infI1
  2084     meet_leI2               ~> le_infI2
  2085     le_joinI1               ~> le_supI1
  2086     le_joinI2               ~> le_supI2
  2087     meet_assoc              ~> inf_assoc
  2088     join_assoc              ~> sup_assoc
  2089     meet_left_comm          ~> inf_left_commute
  2090     meet_left_idempotent    ~> inf_left_idem
  2091     join_left_comm          ~> sup_left_commute
  2092     join_left_idempotent    ~> sup_left_idem
  2093     meet_aci                ~> inf_aci
  2094     join_aci                ~> sup_aci
  2095     le_def_meet             ~> le_iff_inf
  2096     le_def_join             ~> le_iff_sup
  2097     join_absorp2            ~> sup_absorb2
  2098     join_absorp1            ~> sup_absorb1
  2099     meet_absorp1            ~> inf_absorb1
  2100     meet_absorp2            ~> inf_absorb2
  2101     meet_join_absorp        ~> inf_sup_absorb
  2102     join_meet_absorp        ~> sup_inf_absorb
  2103     distrib_join_le         ~> distrib_sup_le
  2104     distrib_meet_le         ~> distrib_inf_le
  2105 
  2106     add_meet_distrib_left   ~> add_inf_distrib_left
  2107     add_join_distrib_left   ~> add_sup_distrib_left
  2108     is_join_neg_meet        ~> is_join_neg_inf
  2109     is_meet_neg_join        ~> is_meet_neg_sup
  2110     add_meet_distrib_right  ~> add_inf_distrib_right
  2111     add_join_distrib_right  ~> add_sup_distrib_right
  2112     add_meet_join_distribs  ~> add_sup_inf_distribs
  2113     join_eq_neg_meet        ~> sup_eq_neg_inf
  2114     meet_eq_neg_join        ~> inf_eq_neg_sup
  2115     add_eq_meet_join        ~> add_eq_inf_sup
  2116     meet_0_imp_0            ~> inf_0_imp_0
  2117     join_0_imp_0            ~> sup_0_imp_0
  2118     meet_0_eq_0             ~> inf_0_eq_0
  2119     join_0_eq_0             ~> sup_0_eq_0
  2120     neg_meet_eq_join        ~> neg_inf_eq_sup
  2121     neg_join_eq_meet        ~> neg_sup_eq_inf
  2122     join_eq_if              ~> sup_eq_if
  2123 
  2124     mono_meet               ~> mono_inf
  2125     mono_join               ~> mono_sup
  2126     meet_bool_eq            ~> inf_bool_eq
  2127     join_bool_eq            ~> sup_bool_eq
  2128     meet_fun_eq             ~> inf_fun_eq
  2129     join_fun_eq             ~> sup_fun_eq
  2130     meet_set_eq             ~> inf_set_eq
  2131     join_set_eq             ~> sup_set_eq
  2132     meet1_iff               ~> inf1_iff
  2133     meet2_iff               ~> inf2_iff
  2134     meet1I                  ~> inf1I
  2135     meet2I                  ~> inf2I
  2136     meet1D1                 ~> inf1D1
  2137     meet2D1                 ~> inf2D1
  2138     meet1D2                 ~> inf1D2
  2139     meet2D2                 ~> inf2D2
  2140     meet1E                  ~> inf1E
  2141     meet2E                  ~> inf2E
  2142     join1_iff               ~> sup1_iff
  2143     join2_iff               ~> sup2_iff
  2144     join1I1                 ~> sup1I1
  2145     join2I1                 ~> sup2I1
  2146     join1I1                 ~> sup1I1
  2147     join2I2                 ~> sup1I2
  2148     join1CI                 ~> sup1CI
  2149     join2CI                 ~> sup2CI
  2150     join1E                  ~> sup1E
  2151     join2E                  ~> sup2E
  2152 
  2153     is_meet_Meet            ~> is_meet_Inf
  2154     Meet_bool_def           ~> Inf_bool_def
  2155     Meet_fun_def            ~> Inf_fun_def
  2156     Meet_greatest           ~> Inf_greatest
  2157     Meet_lower              ~> Inf_lower
  2158     Meet_set_def            ~> Inf_set_def
  2159 
  2160     Sup_def                 ~> Sup_Inf
  2161     Sup_bool_eq             ~> Sup_bool_def
  2162     Sup_fun_eq              ~> Sup_fun_def
  2163     Sup_set_eq              ~> Sup_set_def
  2164 
  2165     listsp_meetI            ~> listsp_infI
  2166     listsp_meet_eq          ~> listsp_inf_eq
  2167 
  2168     meet_min                ~> inf_min
  2169     join_max                ~> sup_max
  2170 
  2171 * Added syntactic class "size"; overloaded constant "size" now has
  2172 type "'a::size ==> bool"
  2173 
  2174 * Internal reorganisation of `size' of datatypes: size theorems
  2175 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2176 simplification rules by default!); theorems "prod.size" now named
  2177 "*.size".
  2178 
  2179 * Class "div" now inherits from class "times" rather than "type".
  2180 INCOMPATIBILITY.
  2181 
  2182 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2183 Linorder etc.  have disappeared; operations defined in terms of
  2184 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2185 
  2186 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2187 
  2188 * HOL-Word: New extensive library and type for generic, fixed size
  2189 machine words, with arithemtic, bit-wise, shifting and rotating
  2190 operations, reflection into int, nat, and bool lists, automation for
  2191 linear arithmetic (by automatic reflection into nat or int), including
  2192 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2193 arithmetic type classes, supporting automatic simplification of
  2194 numerals on all operations.
  2195 
  2196 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2197 
  2198 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2199 
  2200 * Code generator library theories:
  2201   - Code_Integer represents HOL integers by big integer literals in target
  2202     languages.
  2203   - Code_Char represents HOL characters by character literals in target
  2204     languages.
  2205   - Code_Char_chr like Code_Char, but also offers treatment of character
  2206     codes; includes Code_Integer.
  2207   - Executable_Set allows to generate code for finite sets using lists.
  2208   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2209     denominator).
  2210   - Executable_Real implements a subset of real numbers, namly those
  2211     representable by rational numbers.
  2212   - Efficient_Nat implements natural numbers by integers, which in general will
  2213     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2214     includes Code_Integer.
  2215   - Code_Index provides an additional datatype index which is mapped to
  2216     target-language built-in integers.
  2217   - Code_Message provides an additional datatype message_string which is isomorphic to
  2218     strings; messages are mapped to target-language strings.
  2219 
  2220 * New package for inductive predicates
  2221 
  2222   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2223 
  2224     inductive
  2225       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2226       for z_1 :: U_1 and ... and z_n :: U_m
  2227     where
  2228       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2229     | ...
  2230 
  2231   with full support for type-inference, rather than
  2232 
  2233     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2234 
  2235     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2236     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2237 
  2238     inductive "s z_1 ... z_m"
  2239     intros
  2240       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2241       ...
  2242 
  2243   For backward compatibility, there is a wrapper allowing inductive
  2244   sets to be defined with the new package via
  2245 
  2246     inductive_set
  2247       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2248       for z_1 :: U_1 and ... and z_n :: U_m
  2249     where
  2250       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2251     | ...
  2252 
  2253   or
  2254 
  2255     inductive_set
  2256       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2257       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2258       for z_1 :: U_1 and ... and z_n :: U_m
  2259     where
  2260       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2261     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2262     | ...
  2263 
  2264   if the additional syntax "p ..." is required.
  2265 
  2266   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2267   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2268 
  2269   INCOMPATIBILITIES:
  2270 
  2271   - Since declaration and definition of inductive sets or predicates
  2272     is no longer separated, abbreviations involving the newly
  2273     introduced sets or predicates must be specified together with the
  2274     introduction rules after the 'where' keyword (see above), rather
  2275     than before the actual inductive definition.
  2276 
  2277   - The variables in induction and elimination rules are now
  2278     quantified in the order of their occurrence in the introduction
  2279     rules, rather than in alphabetical order. Since this may break
  2280     some proofs, these proofs either have to be repaired, e.g. by
  2281     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2282     statements of the form
  2283 
  2284       case (rule_i a_i_1 ... a_i_{k_i})
  2285 
  2286     or the old order of quantification has to be restored by explicitly adding
  2287     meta-level quantifiers in the introduction rules, i.e.
  2288 
  2289       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2290 
  2291   - The format of the elimination rules is now
  2292 
  2293       p z_1 ... z_m x_1 ... x_n ==>
  2294         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2295         ==> ... ==> P
  2296 
  2297     for predicates and
  2298 
  2299       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2300         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2301         ==> ... ==> P
  2302 
  2303     for sets rather than
  2304 
  2305       x : s z_1 ... z_m ==>
  2306         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2307         ==> ... ==> P
  2308 
  2309     This may require terms in goals to be expanded to n-tuples
  2310     (e.g. using case_tac or simplification with the split_paired_all
  2311     rule) before the above elimination rule is applicable.
  2312 
  2313   - The elimination or case analysis rules for (mutually) inductive
  2314     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2315     list of rules "p_1_..._p_k.elims" is no longer available.
  2316 
  2317 * New package "function"/"fun" for general recursive functions,
  2318 supporting mutual and nested recursion, definitions in local contexts,
  2319 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2320 for small examples, and the separate tutorial on the function
  2321 package. The old recdef "package" is still available as before, but
  2322 users are encouraged to use the new package.
  2323 
  2324 * Method "lexicographic_order" automatically synthesizes termination
  2325 relations as lexicographic combinations of size measures. 
  2326 
  2327 * Case-expressions allow arbitrary constructor-patterns (including
  2328 "_") and take their order into account, like in functional
  2329 programming.  Internally, this is translated into nested
  2330 case-expressions; missing cases are added and mapped to the predefined
  2331 constant "undefined". In complicated cases printing may no longer show
  2332 the original input but the internal form. Lambda-abstractions allow
  2333 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2334 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2335 variable.
  2336 
  2337 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2338 is an abbreviation for "of_nat :: nat => int". The simplification
  2339 rules for "of_nat" have been changed to work like "int" did
  2340 previously.  Potential INCOMPATIBILITY:
  2341   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2342   - of_nat_diff and of_nat_mult are no longer default simp rules
  2343 
  2344 * Method "algebra" solves polynomial equations over (semi)rings using
  2345 Groebner bases. The (semi)ring structure is defined by locales and the
  2346 tool setup depends on that generic context. Installing the method for
  2347 a specific type involves instantiating the locale and possibly adding
  2348 declarations for computation on the coefficients.  The method is
  2349 already instantiated for natural numbers and for the axiomatic class
  2350 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2351 CALCULEMUS 2007 for the general principles underlying this
  2352 architecture of context-aware proof-tools.
  2353 
  2354 * Method "ferrack" implements quantifier elimination over
  2355 special-purpose dense linear orders using locales (analogous to
  2356 "algebra"). The method is already installed for class
  2357 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2358 rat, etc.
  2359 
  2360 * Former constant "List.op @" now named "List.append".  Use ML
  2361 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2362 circumvent possible incompatibilities when working on ML level.
  2363 
  2364 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2365 
  2366 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2367 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2368 
  2369 * New syntax for Haskell-like list comprehension (input only), eg.
  2370 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2371 
  2372 * The special syntax for function "filter" has changed from [x :
  2373 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2374 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2375 
  2376 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2377 defined on nat only, as an abbreviation for [a..<Suc b]
  2378 INCOMPATIBILITY.
  2379 
  2380 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2381 
  2382 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2383 
  2384 * New lemma collection field_simps (an extension of ring_simps) for
  2385 manipulating (in)equations involving division. Multiplies with all
  2386 denominators that can be proved to be non-zero (in equations) or
  2387 positive/negative (in inequations).
  2388 
  2389 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2390 have been improved and renamed to ring_simps, group_simps and
  2391 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2392 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2393 
  2394 * Theory Library/Commutative_Ring: switched from recdef to function
  2395 package; constants add, mul, pow now curried.  Infix syntax for
  2396 algebraic operations.
  2397 
  2398 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2399 INCOMPATIBILITY.
  2400 
  2401 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2402 INCOMPATIBILITY.
  2403 
  2404 * HOL/records: generalised field-update to take a function on the
  2405 field rather than the new value: r(|A := x|) is translated to A_update
  2406 (K x) r The K-combinator that is internally used is called K_record.
  2407 INCOMPATIBILITY: Usage of the plain update functions has to be
  2408 adapted.
  2409  
  2410 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2411 * x = 0, which are required for a semiring.  Richer structures do not
  2412 inherit from semiring_0 anymore, because this property is a theorem
  2413 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2414 there is more to prove, but this is mostly trivial.
  2415 
  2416 * Class "recpower" is generalized to arbitrary monoids, not just
  2417 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2418 commutativity or semiring properties additionally.
  2419 
  2420 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2421 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2422 better use 'abbreviation'.
  2423 
  2424 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2425 
  2426 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2427 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2428 significant changes for setting up numeral syntax for types:
  2429   - New constants Numeral.pred and Numeral.succ instead
  2430       of former Numeral.bin_pred and Numeral.bin_succ.
  2431   - Use integer operations instead of bin_add, bin_mult and so on.
  2432   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2433   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2434 
  2435 See src/HOL/Integ/IntArith.thy for an example setup.
  2436 
  2437 * Command 'normal_form' computes the normal form of a term that may
  2438 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2439 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2440 heavy-duty computations because the functions are compiled to ML
  2441 first.  Correspondingly, a method "normalization" is provided.  See
  2442 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2443 
  2444 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2445 25 like -->); output depends on the "iff" print_mode, the default is
  2446 "A = B" (with priority 50).
  2447 
  2448 * Relations less (<) and less_eq (<=) are also available on type bool.
  2449 Modified syntax to disallow nesting without explicit parentheses,
  2450 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2451 INCOMPATIBILITY.
  2452 
  2453 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2454 
  2455 * Relation composition operator "op O" now has precedence 75 and binds
  2456 stronger than union and intersection. INCOMPATIBILITY.
  2457 
  2458 * The old set interval syntax "{m..n(}" (and relatives) has been
  2459 removed.  Use "{m..<n}" (and relatives) instead.
  2460 
  2461 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2462 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2463 ``declare [[simproc del: neq]]''.
  2464 
  2465 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2466 True/False.
  2467 
  2468 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2469 
  2470 * Theorem setsum_mult renamed to setsum_right_distrib.
  2471 
  2472 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2473 ``rule'' method.
  2474 
  2475 * Reimplemented methods "sat" and "satx", with several improvements:
  2476 goals no longer need to be stated as "<prems> ==> False", equivalences
  2477 (i.e. "=" on type bool) are handled, variable names of the form
  2478 "lit_<n>" are no longer reserved, significant speedup.
  2479 
  2480 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2481 zChaff is still supported as well.
  2482 
  2483 * 'inductive' and 'datatype': provide projections of mutual rules,
  2484 bundled as foo_bar.inducts;
  2485 
  2486 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2487 Library.
  2488 
  2489 * Library: moved theory Accessible_Part to main HOL.
  2490 
  2491 * Library: added theory Coinductive_List of potentially infinite lists
  2492 as greatest fixed-point.
  2493 
  2494 * Library: added theory AssocList which implements (finite) maps as
  2495 association lists.
  2496 
  2497 * Method "evaluation" solves goals (i.e. a boolean expression)
  2498 efficiently by compiling it to ML.  The goal is "proved" (via an
  2499 oracle) if it evaluates to True.
  2500 
  2501 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2502 also when invoked by the simplifier.  This results in the Simplifier
  2503 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2504 Configuration option fast_arith_split_limit=0 recovers the old
  2505 behavior.
  2506 
  2507 * Support for hex (0x20) and binary (0b1001) numerals.
  2508 
  2509 * New method: reify eqs (t), where eqs are equations for an
  2510 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2511 parameter, computes a term s::'b and a list xs::'a list and proves the
  2512 theorem I xs s = t. This is also known as reification or quoting. The
  2513 resulting theorem is applied to the subgoal to substitute t with I xs
  2514 s.  If t is omitted, the subgoal itself is reified.
  2515 
  2516 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2517 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2518 where f is supposed to be a computable function (in the sense of code
  2519 generattion). The method uses reify to compute s and xs as above then
  2520 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2521 r and finally gets the theorem t = r, which is again applied to the
  2522 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2523 
  2524 * Reflection: Automatic reification now handels binding, an example is
  2525 available in src/HOL/ex/ReflectionEx.thy
  2526 
  2527 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2528 command 'statespace' that is similar to 'record', but introduces an
  2529 abstract specification based on the locale infrastructure instead of
  2530 HOL types.  This leads to extra flexibility in composing state spaces,
  2531 in particular multiple inheritance and renaming of components.
  2532 
  2533 
  2534 *** HOL-Complex ***
  2535 
  2536 * Hyperreal: Functions root and sqrt are now defined on negative real
  2537 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2538 Nonnegativity side conditions have been removed from many lemmas, so
  2539 that more subgoals may now be solved by simplification; potential
  2540 INCOMPATIBILITY.
  2541 
  2542 * Real: new type classes formalize real normed vector spaces and
  2543 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2544 and norm :: 'a => real.
  2545 
  2546 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2547 reals into other types. The overloaded constant Reals :: 'a set is now
  2548 defined as range of_real; potential INCOMPATIBILITY.
  2549 
  2550 * Real: proper support for ML code generation, including 'quickcheck'.
  2551 Reals are implemented as arbitrary precision rationals.
  2552 
  2553 * Hyperreal: Several constants that previously worked only for the
  2554 reals have been generalized, so they now work over arbitrary vector
  2555 spaces. Type annotations may need to be added in some cases; potential
  2556 INCOMPATIBILITY.
  2557 
  2558   Infinitesimal  :: ('a::real_normed_vector) star set
  2559   HFinite        :: ('a::real_normed_vector) star set
  2560   HInfinite      :: ('a::real_normed_vector) star set
  2561   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2562   monad          :: ('a::real_normed_vector) star => 'a star set
  2563   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2564   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2565   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2566   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2567   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2568   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2569   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2570   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2571   sgn            :: 'a::real_normed_vector => 'a
  2572   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2573 
  2574 * Complex: Some complex-specific constants are now abbreviations for
  2575 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2576 hnorm.  Other constants have been entirely removed in favor of the
  2577 polymorphic versions (INCOMPATIBILITY):
  2578 
  2579   approx        <-- capprox
  2580   HFinite       <-- CFinite
  2581   HInfinite     <-- CInfinite
  2582   Infinitesimal <-- CInfinitesimal
  2583   monad         <-- cmonad
  2584   galaxy        <-- cgalaxy
  2585   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2586   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2587   (ns)deriv     <-- (ns)cderiv
  2588 
  2589 
  2590 *** HOL-Algebra ***
  2591 
  2592 * Formalisation of ideals and the quotient construction over rings.
  2593 
  2594 * Order and lattice theory no longer based on records.
  2595 INCOMPATIBILITY.
  2596 
  2597 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2598 greatest_closed.  INCOMPATIBILITY.
  2599 
  2600 * Method algebra is now set up via an attribute.  For examples see
  2601 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2602 of algebraic structures.
  2603 
  2604 * Renamed theory CRing to Ring.
  2605 
  2606 
  2607 *** HOL-Nominal ***
  2608 
  2609 * Substantial, yet incomplete support for nominal datatypes (binding
  2610 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2611 src/HOL/Nominal/Examples.  Prospective users should consult
  2612 http://isabelle.in.tum.de/nominal/
  2613 
  2614 
  2615 *** ML ***
  2616 
  2617 * ML basics: just one true type int, which coincides with IntInf.int
  2618 (even on SML/NJ).
  2619 
  2620 * ML within Isar: antiquotations allow to embed statically-checked
  2621 formal entities in the source, referring to the context available at
  2622 compile-time.  For example:
  2623 
  2624 ML {* @{sort "{zero,one}"} *}
  2625 ML {* @{typ "'a => 'b"} *}
  2626 ML {* @{term "%x. x"} *}
  2627 ML {* @{prop "x == y"} *}
  2628 ML {* @{ctyp "'a => 'b"} *}
  2629 ML {* @{cterm "%x. x"} *}
  2630 ML {* @{cprop "x == y"} *}
  2631 ML {* @{thm asm_rl} *}
  2632 ML {* @{thms asm_rl} *}
  2633 ML {* @{type_name c} *}
  2634 ML {* @{type_syntax c} *}
  2635 ML {* @{const_name c} *}
  2636 ML {* @{const_syntax c} *}
  2637 ML {* @{context} *}
  2638 ML {* @{theory} *}
  2639 ML {* @{theory Pure} *}
  2640 ML {* @{theory_ref} *}
  2641 ML {* @{theory_ref Pure} *}
  2642 ML {* @{simpset} *}
  2643 ML {* @{claset} *}
  2644 ML {* @{clasimpset} *}
  2645 
  2646 The same works for sources being ``used'' within an Isar context.
  2647 
  2648 * ML in Isar: improved error reporting; extra verbosity with
  2649 ML_Context.trace enabled.
  2650 
  2651 * Pure/General/table.ML: the join operations now works via exceptions
  2652 DUP/SAME instead of type option. This is simpler in simple cases, and
  2653 admits slightly more efficient complex applications.
  2654 
  2655 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2656 use Context.generic instead of just theory.
  2657 
  2658 * Pure: datatype Context.generic joins theory/Proof.context and
  2659 provides some facilities for code that works in either kind of
  2660 context, notably GenericDataFun for uniform theory and proof data.
  2661 
  2662 * Pure: simplified internal attribute type, which is now always
  2663 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2664 local (Proof.context) attributes have been discontinued, while
  2665 minimizing code duplication. Thm.rule_attribute and
  2666 Thm.declaration_attribute build canonical attributes; see also structure
  2667 Context for further operations on Context.generic, notably
  2668 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2669 declarations and definitions.
  2670 
  2671 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2672 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2673 init only required for impure data. INCOMPATIBILITY: empty really need
  2674 to be empty (no dependencies on theory content!)
  2675 
  2676 * Pure/kernel: consts certification ignores sort constraints given in
  2677 signature declarations. (This information is not relevant to the
  2678 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2679 potential INCOMPATIBILITY.
  2680 
  2681 * Pure: axiomatic type classes are now purely definitional, with
  2682 explicit proofs of class axioms and super class relations performed
  2683 internally. See Pure/axclass.ML for the main internal interfaces --
  2684 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2685 AxClass.axiomatize_class/classrel/arity supersede
  2686 Sign.add_classes/classrel/arities.
  2687 
  2688 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2689 global/local versions on theory vs. Proof.context have been
  2690 discontinued; Attrib.syntax and Method.syntax have been adapted
  2691 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2692 attributes, methods, etc.
  2693 
  2694 * Pure: several functions of signature "... -> theory -> theory * ..."
  2695 have been reoriented to "... -> theory -> ... * theory" in order to
  2696 allow natural usage in combination with the ||>, ||>>, |-> and
  2697 fold_map combinators.
  2698 
  2699 * Pure: official theorem names (closed derivations) and additional
  2700 comments (tags) are now strictly separate.  Name hints -- which are
  2701 maintained as tags -- may be attached any time without affecting the
  2702 derivation.
  2703 
  2704 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2705 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2706 achieve the old behaviour.
  2707 
  2708 * Pure: the "Goal" constant is now called "prop", supporting a
  2709 slightly more general idea of ``protecting'' meta-level rule
  2710 statements.
  2711 
  2712 * Pure: Logic.(un)varify only works in a global context, which is now
  2713 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2714 Logic.legacy_(un)varify as temporary workaround.
  2715 
  2716 * Pure: structure Name provides scalable operations for generating
  2717 internal variable names, notably Name.variants etc.  This replaces
  2718 some popular functions from term.ML:
  2719 
  2720   Term.variant		->  Name.variant
  2721   Term.variantlist	->  Name.variant_list
  2722   Term.invent_names	->  Name.invent_list
  2723 
  2724 Note that low-level renaming rarely occurs in new code -- operations
  2725 from structure Variable are used instead (see below).
  2726 
  2727 * Pure: structure Variable provides fundamental operations for proper
  2728 treatment of fixed/schematic variables in a context.  For example,
  2729 Variable.import introduces fixes for schematics of given facts and
  2730 Variable.export reverses the effect (up to renaming) -- this replaces
  2731 various freeze_thaw operations.
  2732 
  2733 * Pure: structure Goal provides simple interfaces for
  2734 init/conclude/finish and tactical prove operations (replacing former
  2735 Tactic.prove).  Goal.prove is the canonical way to prove results
  2736 within a given context; Goal.prove_global is a degraded version for
  2737 theory level goals, including a global Drule.standard.  Note that
  2738 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2739 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2740 in a locale context).
  2741 
  2742 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2743 and type checking (Syntax.check_term etc.), with common combinations
  2744 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2745 which are considered legacy and await removal.
  2746 
  2747 * Pure/Syntax: generic interfaces for type unchecking
  2748 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2749 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2750 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2751 available for convenience, but refer to the very same operations using
  2752 a mere theory instead of a full context.
  2753 
  2754 * Isar: simplified treatment of user-level errors, using exception
  2755 ERROR of string uniformly.  Function error now merely raises ERROR,
  2756 without any side effect on output channels.  The Isar toplevel takes
  2757 care of proper display of ERROR exceptions.  ML code may use plain
  2758 handle/can/try; cat_error may be used to concatenate errors like this:
  2759 
  2760   ... handle ERROR msg => cat_error msg "..."
  2761 
  2762 Toplevel ML code (run directly or through the Isar toplevel) may be
  2763 embedded into the Isar toplevel with exception display/debug like
  2764 this:
  2765 
  2766   Isar.toplevel (fn () => ...)
  2767 
  2768 INCOMPATIBILITY, removed special transform_error facilities, removed
  2769 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2770 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2771 -- use plain ERROR instead.
  2772 
  2773 * Isar: theory setup now has type (theory -> theory), instead of a
  2774 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2775 
  2776 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2777 ProofContext.debug/verbose flags.
  2778 
  2779 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2780 theory before entering a proof state.  Transactions now always see a
  2781 quasi-functional intermediate checkpoint, both in interactive and
  2782 batch mode.
  2783 
  2784 * Isar: simplified interfaces for outer syntax.  Renamed
  2785 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2786 OuterSyntax.add_parsers -- this functionality is now included in
  2787 OuterSyntax.command etc.  INCOMPATIBILITY.
  2788 
  2789 * Simplifier: the simpset of a running simplification process now
  2790 contains a proof context (cf. Simplifier.the_context), which is the
  2791 very context that the initial simpset has been retrieved from (by
  2792 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2793 (solver, looper etc.) may depend on arbitrary proof data.
  2794 
  2795 * Simplifier.inherit_context inherits the proof context (plus the
  2796 local bounds) of the current simplification process; any simproc
  2797 etc. that calls the Simplifier recursively should do this!  Removed
  2798 former Simplifier.inherit_bounds, which is already included here --
  2799 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2800 specify an explicit context using Simplifier.context/theory_context.
  2801 
  2802 * Simplifier/Classical Reasoner: more abstract interfaces
  2803 change_simpset/claset for modifying the simpset/claset reference of a
  2804 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2805 INCOMPATIBILITY.
  2806 
  2807 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2808 "Trueprop" etc.
  2809 
  2810 
  2811 *** System ***
  2812 
  2813 * settings: the default heap location within ISABELLE_HOME_USER now
  2814 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2815 Isabelle installations.
  2816 
  2817 * isabelle-process: option -S (secure mode) disables some critical
  2818 operations, notably runtime compilation and evaluation of ML source
  2819 code.
  2820 
  2821 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2822 
  2823 * Support for parallel execution, using native multicore support of
  2824 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2825 independent theories, according to the given theory header
  2826 specifications. The maximum number of worker threads is specified via
  2827 usedir option -M or the "max-threads" setting in Proof General. A
  2828 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2829 to 6 on a 8-core machine.  User-code needs to observe certain
  2830 guidelines for thread-safe programming, see appendix A in the Isar
  2831 Implementation manual.
  2832 
  2833 
  2834 
  2835 New in Isabelle2005 (October 2005)
  2836 ----------------------------------
  2837 
  2838 *** General ***
  2839 
  2840 * Theory headers: the new header syntax for Isar theories is
  2841 
  2842   theory <name>
  2843   imports <theory1> ... <theoryN>
  2844   uses <file1> ... <fileM>
  2845   begin
  2846 
  2847 where the 'uses' part is optional.  The previous syntax
  2848 
  2849   theory <name> = <theory1> + ... + <theoryN>:
  2850 
  2851 will disappear in the next release.  Use isatool fixheaders to convert
  2852 existing theory files.  Note that there is no change in ancient
  2853 non-Isar theories now, but these will disappear soon.
  2854 
  2855 * Theory loader: parent theories can now also be referred to via
  2856 relative and absolute paths.
  2857 
  2858 * Command 'find_theorems' searches for a list of criteria instead of a
  2859 list of constants. Known criteria are: intro, elim, dest, name:string,
  2860 simp:term, and any term. Criteria can be preceded by '-' to select
  2861 theorems that do not match. Intro, elim, dest select theorems that
  2862 match the current goal, name:s selects theorems whose fully qualified
  2863 name contain s, and simp:term selects all simplification rules whose
  2864 lhs match term.  Any other term is interpreted as pattern and selects
  2865 all theorems matching the pattern. Available in ProofGeneral under
  2866 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2867 
  2868   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2869 
  2870 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2871 matching the current goal as introduction rule and not having "HOL."
  2872 in their name (i.e. not being defined in theory HOL).
  2873 
  2874 * Command 'thms_containing' has been discontinued in favour of
  2875 'find_theorems'; INCOMPATIBILITY.
  2876 
  2877 * Communication with Proof General is now 8bit clean, which means that
  2878 Unicode text in UTF-8 encoding may be used within theory texts (both
  2879 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2880 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2881 
  2882   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2883   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2884 
  2885 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2886 Classical Reasoner.  Typical big applications run around 2 times
  2887 faster.
  2888 
  2889 
  2890 *** Document preparation ***
  2891 
  2892 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2893 of raw sources.  Only those symbols that do not require additional
  2894 LaTeX packages (depending on comments in isabellesym.sty) are
  2895 displayed properly, everything else is left verbatim.  isatool display
  2896 and isatool print are used as front ends (these are subject to the
  2897 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2898 
  2899 * Command tags control specific markup of certain regions of text,
  2900 notably folding and hiding.  Predefined tags include "theory" (for
  2901 theory begin and end), "proof" for proof commands, and "ML" for
  2902 commands involving ML code; the additional tags "visible" and
  2903 "invisible" are unused by default.  Users may give explicit tag
  2904 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2905 interpretation of tags is determined by the LaTeX job during document
  2906 preparation: see option -V of isatool usedir, or options -n and -t of
  2907 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2908 \isadroptag.
  2909 
  2910 Several document versions may be produced at the same time via isatool
  2911 usedir (the generated index.html will link all of them).  Typical
  2912 specifications include ''-V document=theory,proof,ML'' to present
  2913 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2914 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2915 these parts without any formal replacement text.  The Isabelle site
  2916 default settings produce ''document'' and ''outline'' versions as
  2917 specified above.
  2918 
  2919 * Several new antiquotations:
  2920 
  2921   @{term_type term} prints a term with its type annotated;
  2922 
  2923   @{typeof term} prints the type of a term;
  2924 
  2925   @{const const} is the same as @{term const}, but checks that the
  2926   argument is a known logical constant;
  2927 
  2928   @{term_style style term} and @{thm_style style thm} print a term or
  2929   theorem applying a "style" to it
  2930 
  2931   @{ML text}
  2932 
  2933 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2934 definitions, equations, inequations etc., 'concl' printing only the
  2935 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2936 to print the specified premise.  TermStyle.add_style provides an ML
  2937 interface for introducing further styles.  See also the "LaTeX Sugar"
  2938 document practical applications.  The ML antiquotation prints
  2939 type-checked ML expressions verbatim.
  2940 
  2941 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2942 and 'text' support optional locale specification '(in loc)', which
  2943 specifies the default context for interpreting antiquotations.  For
  2944 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2945 
  2946 * Option 'locale=NAME' of antiquotations specifies an alternative
  2947 context interpreting the subsequent argument.  For example: @{thm
  2948 [locale=lattice] inf_assoc}.
  2949 
  2950 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2951 a proof context.
  2952 
  2953 * Proper output of antiquotations for theory commands involving a
  2954 proof context (such as 'locale' or 'theorem (in loc) ...').
  2955 
  2956 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2957 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2958 
  2959 * isatool usedir: new option -C (default true) controls whether option
  2960 -D should include a copy of the original document directory; -C false
  2961 prevents unwanted effects such as copying of administrative CVS data.
  2962 
  2963 
  2964 *** Pure ***
  2965 
  2966 * Considerably improved version of 'constdefs' command.  Now performs
  2967 automatic type-inference of declared constants; additional support for
  2968 local structure declarations (cf. locales and HOL records), see also
  2969 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2970 sequential dependencies of definitions within a single 'constdefs'
  2971 section; moreover, the declared name needs to be an identifier.  If
  2972 all fails, consider to fall back on 'consts' and 'defs' separately.
  2973 
  2974 * Improved indexed syntax and implicit structures.  First of all,
  2975 indexed syntax provides a notational device for subscripted
  2976 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2977 expressions.  Secondly, in a local context with structure
  2978 declarations, number indexes \<^sub>n or the empty index (default
  2979 number 1) refer to a certain fixed variable implicitly; option
  2980 show_structs controls printing of implicit structures.  Typical
  2981 applications of these concepts involve record types and locales.
  2982 
  2983 * New command 'no_syntax' removes grammar declarations (and
  2984 translations) resulting from the given syntax specification, which is
  2985 interpreted in the same manner as for the 'syntax' command.
  2986 
  2987 * 'Advanced' translation functions (parse_translation etc.) may depend
  2988 on the signature of the theory context being presently used for
  2989 parsing/printing, see also isar-ref manual.
  2990 
  2991 * Improved 'oracle' command provides a type-safe interface to turn an
  2992 ML expression of type theory -> T -> term into a primitive rule of
  2993 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2994 is already included here); see also FOL/ex/IffExample.thy;
  2995 INCOMPATIBILITY.
  2996 
  2997 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2998 before); "cI" is no longer bound, use "c.intro" instead.
  2999 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3000 axclasses vs. locales.
  3001 
  3002 * Improved internal renaming of symbolic identifiers -- attach primes
  3003 instead of base 26 numbers.
  3004 
  3005 * New flag show_question_marks controls printing of leading question
  3006 marks in schematic variable names.
  3007 
  3008 * In schematic variable names, *any* symbol following \<^isub> or
  3009 \<^isup> is now treated as part of the base name.  For example, the
  3010 following works without printing of awkward ".0" indexes:
  3011 
  3012   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3013     by simp
  3014 
  3015 * Inner syntax includes (*(*nested*) comments*).
  3016 
  3017 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3018 annotations as "(00...)".
  3019 
  3020 * Clear separation of logical types and nonterminals, where the latter
  3021 may only occur in 'syntax' specifications or type abbreviations.
  3022 Before that distinction was only partially implemented via type class
  3023 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3024 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3025 exotic syntax specifications may require further adaption
  3026 (e.g. Cube/Cube.thy).
  3027 
  3028 * Removed obsolete type class "logic", use the top sort {} instead.
  3029 Note that non-logical types should be declared as 'nonterminals'
  3030 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3031 specifications.
  3032 
  3033 * Attributes 'induct' and 'cases': type or set names may now be
  3034 locally fixed variables as well.
  3035 
  3036 * Simplifier: can now control the depth to which conditional rewriting
  3037 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3038 Limit.
  3039 
  3040 * Simplifier: simplification procedures may now take the current
  3041 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3042 interface), which is very useful for calling the Simplifier
  3043 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3044 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3045 low-level mk_simproc no longer applies Logic.varify internally, to
  3046 allow for use in a context of fixed variables.
  3047 
  3048 * thin_tac now works even if the assumption being deleted contains !!
  3049 or ==>.  More generally, erule now works even if the major premise of
  3050 the elimination rule contains !! or ==>.
  3051 
  3052 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3053 
  3054 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3055 from Pure, which contains all common declarations already.  Both
  3056 theories are defined via plain Isabelle/Isar .thy files.
  3057 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3058 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3059 use isatool fixcpure to adapt your theory and ML sources.
  3060 
  3061 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3062 selections of theorems in named facts via index ranges.
  3063 
  3064 * 'print_theorems': in theory mode, really print the difference
  3065 wrt. the last state (works for interactive theory development only),
  3066 in proof mode print all local facts (cf. 'print_facts');
  3067 
  3068 * 'hide': option '(open)' hides only base names.
  3069 
  3070 * More efficient treatment of intermediate checkpoints in interactive
  3071 theory development.
  3072 
  3073 * Code generator is now invoked via code_module (incremental code
  3074 generation) and code_library (modular code generation, ML structures
  3075 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3076 must be quoted when used as identifiers.
  3077 
  3078 * New 'value' command for reading, evaluating and printing terms using
  3079 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3080 quoted when used as identifier.
  3081 
  3082 
  3083 *** Locales ***
  3084 
  3085 * New commands for the interpretation of locale expressions in
  3086 theories (1), locales (2) and proof contexts (3).  These generate
  3087 proof obligations from the expression specification.  After the
  3088 obligations have been discharged, theorems of the expression are added
  3089 to the theory, target locale or proof context.  The synopsis of the
  3090 commands is a follows:
  3091 
  3092   (1) interpretation expr inst
  3093   (2) interpretation target < expr
  3094   (3) interpret expr inst
  3095 
  3096 Interpretation in theories and proof contexts require a parameter
  3097 instantiation of terms from the current context.  This is applied to
  3098 specifications and theorems of the interpreted expression.
  3099 Interpretation in locales only permits parameter renaming through the
  3100 locale expression.  Interpretation is smart in that interpretations
  3101 that are active already do not occur in proof obligations, neither are
  3102 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3103 inspect active interpretations of a particular locale.  For details,
  3104 see the Isar Reference manual.  Examples can be found in
  3105 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3106 
  3107 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3108 'interpret' instead.
  3109 
  3110 * New context element 'constrains' for adding type constraints to
  3111 parameters.
  3112 
  3113 * Context expressions: renaming of parameters with syntax
  3114 redeclaration.
  3115 
  3116 * Locale declaration: 'includes' disallowed.
  3117 
  3118 * Proper static binding of attribute syntax -- i.e. types / terms /
  3119 facts mentioned as arguments are always those of the locale definition
  3120 context, independently of the context of later invocations.  Moreover,
  3121 locale operations (renaming and type / term instantiation) are applied
  3122 to attribute arguments as expected.
  3123 
  3124 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3125 actual attributes; rare situations may require Attrib.attribute to
  3126 embed those attributes into Attrib.src that lack concrete syntax.
  3127 Attribute implementations need to cooperate properly with the static
  3128 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3129 Attrib.XXX_thm etc. already do the right thing without further
  3130 intervention.  Only unusual applications -- such as "where" or "of"
  3131 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3132 on the context and the facts involved -- may have to assign parsed
  3133 values to argument tokens explicitly.
  3134 
  3135 * Changed parameter management in theorem generation for long goal
  3136 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3137 theorem statement in rare situations.
  3138 
  3139 * Locale inspection command 'print_locale' omits notes elements.  Use
  3140 'print_locale!' to have them included in the output.
  3141 
  3142 
  3143 *** Provers ***
  3144 
  3145 * Provers/hypsubst.ML: improved version of the subst method, for
  3146 single-step rewriting: it now works in bound variable contexts. New is
  3147 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3148 rewrite a different subterm than the original subst method, which is
  3149 still available as 'simplesubst'.
  3150 
  3151 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3152 and quasi orders.
  3153 
  3154 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3155 reflexive-transitive closure of relations.
  3156 
  3157 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3158 limit (previously hard-coded with a value of 20) user-definable.
  3159 
  3160 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3161 is peformed already.  Object-logics merely need to finish their
  3162 initial simpset configuration as before.  INCOMPATIBILITY.
  3163 
  3164 
  3165 *** HOL ***
  3166 
  3167 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3168 
  3169   syntax (epsilon)
  3170     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3171 
  3172 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3173 and x-symbol; use option '-m epsilon' to get it actually printed.
  3174 Moreover, the mathematically important symbolic identifier \<epsilon>
  3175 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3176 
  3177 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3178 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3179 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3180 support corresponding Isar calculations.
  3181 
  3182 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3183 instead of ":".
  3184 
  3185 * theory SetInterval: changed the syntax for open intervals:
  3186 
  3187   Old       New
  3188   {..n(}    {..<n}
  3189   {)n..}    {n<..}
  3190   {m..n(}   {m..<n}
  3191   {)m..n}   {m<..n}
  3192   {)m..n(}  {m<..<n}
  3193 
  3194 The old syntax is still supported but will disappear in the next
  3195 release.  For conversion use the following Emacs search and replace
  3196 patterns (these are not perfect but work quite well):
  3197 
  3198   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3199   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3200 
  3201 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3202 equalities in commutative rings; method 'algebra' provides a generic
  3203 interface.
  3204 
  3205 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3206 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3207 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3208 be a tuple pattern.
  3209 
  3210 Some new syntax forms are available:
  3211 
  3212   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3213   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3214   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3215   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3216 
  3217 The latter form "\<Sum>x < k. e" used to be based on a separate
  3218 function "Summation", which has been discontinued.
  3219 
  3220 * theory Finite_Set: in structured induction proofs, the insert case
  3221 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3222 (insert F x)'.
  3223 
  3224 * The 'refute' command has been extended to support a much larger
  3225 fragment of HOL, including axiomatic type classes, constdefs and
  3226 typedefs, inductive datatypes and recursion.
  3227 
  3228 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3229 Requires zChaff with proof generation to be installed.  See
  3230 HOL/ex/SAT_Examples.thy for examples.
  3231 
  3232 * Datatype induction via method 'induct' now preserves the name of the
  3233 induction variable. For example, when proving P(xs::'a list) by
  3234 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3235 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3236 in unstructured proof scripts.
  3237 
  3238 * Reworked implementation of records.  Improved scalability for
  3239 records with many fields, avoiding performance problems for type
  3240 inference. Records are no longer composed of nested field types, but
  3241 of nested extension types. Therefore the record type only grows linear
  3242 in the number of extensions and not in the number of fields.  The
  3243 top-level (users) view on records is preserved.  Potential
  3244 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3245 old record representation. The type generated for a record is called
  3246 <record_name>_ext_type.
  3247 
  3248 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3249 proofs triggered by a record definition or a simproc (if
  3250 quick_and_dirty is enabled).  Definitions of large records can take
  3251 quite long.
  3252 
  3253 New simproc record_upd_simproc for simplification of multiple record
  3254 updates enabled by default.  Moreover, trivial updates are also
  3255 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3256 occasionally, since simplification is more powerful by default.
  3257 
  3258 * typedef: proper support for polymorphic sets, which contain extra
  3259 type-variables in the term.
  3260 
  3261 * Simplifier: automatically reasons about transitivity chains
  3262 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3263 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3264 old proofs break occasionally as simplification may now solve more
  3265 goals than previously.
  3266 
  3267 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3268 present.  Works for all partial orders (class "order"), in particular
  3269 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3270 just like y <= x.
  3271 
  3272 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3273 bound variable or a constant then the let is unfolded.  Otherwise
  3274 first a is simplified to b, and then f b is simplified to g. If
  3275 possible we abstract b from g arriving at "let x = b in h x",
  3276 otherwise we unfold the let and arrive at g.  The simproc can be
  3277 enabled/disabled by the reference use_let_simproc.  Potential
  3278 INCOMPATIBILITY since simplification is more powerful by default.
  3279 
  3280 * Classical reasoning: the meson method now accepts theorems as arguments.
  3281 
  3282 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3283 jobs to provide advice on the provability of subgoals.
  3284 
  3285 * Theory OrderedGroup and Ring_and_Field: various additions and
  3286 improvements to faciliate calculations involving equalities and
  3287 inequalities.
  3288 
  3289 The following theorems have been eliminated or modified
  3290 (INCOMPATIBILITY):
  3291 
  3292   abs_eq             now named abs_of_nonneg
  3293   abs_of_ge_0        now named abs_of_nonneg
  3294   abs_minus_eq       now named abs_of_nonpos
  3295   imp_abs_id         now named abs_of_nonneg
  3296   imp_abs_neg_id     now named abs_of_nonpos
  3297   mult_pos           now named mult_pos_pos
  3298   mult_pos_le        now named mult_nonneg_nonneg
  3299   mult_pos_neg_le    now named mult_nonneg_nonpos
  3300   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3301   mult_neg           now named mult_neg_neg
  3302   mult_neg_le        now named mult_nonpos_nonpos
  3303 
  3304 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3305      
  3306      zero_le_square
  3307      not_square_less_zero 
  3308 
  3309   The following lemmas have been deleted from Real/RealPow:
  3310   
  3311      realpow_zero_zero
  3312      realpow_two
  3313      realpow_less
  3314      zero_le_power
  3315      realpow_two_le
  3316      abs_realpow_two
  3317      realpow_two_abs     
  3318 
  3319 * Theory Parity: added rules for simplifying exponents.
  3320 
  3321 * Theory List:
  3322 
  3323 The following theorems have been eliminated or modified
  3324 (INCOMPATIBILITY):
  3325 
  3326   list_all_Nil       now named list_all.simps(1)
  3327   list_all_Cons      now named list_all.simps(2)
  3328   list_all_conv      now named list_all_iff
  3329   set_mem_eq         now named mem_iff
  3330 
  3331 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3332 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3333 
  3334 
  3335 *** HOL-Complex ***
  3336 
  3337 * Theory RealDef: better support for embedding natural numbers and
  3338 integers in the reals.
  3339 
  3340 The following theorems have been eliminated or modified
  3341 (INCOMPATIBILITY):
  3342 
  3343   exp_ge_add_one_self  now requires no hypotheses
  3344   real_of_int_add      reversed direction of equality (use [symmetric])
  3345   real_of_int_minus    reversed direction of equality (use [symmetric])
  3346   real_of_int_diff     reversed direction of equality (use [symmetric])
  3347   real_of_int_mult     reversed direction of equality (use [symmetric])
  3348 
  3349 * Theory RComplete: expanded support for floor and ceiling functions.
  3350 
  3351 * Theory Ln is new, with properties of the natural logarithm
  3352 
  3353 * Hyperreal: There is a new type constructor "star" for making
  3354 nonstandard types.  The old type names are now type synonyms:
  3355 
  3356   hypreal = real star
  3357   hypnat = nat star
  3358   hcomplex = complex star
  3359 
  3360 * Hyperreal: Many groups of similarly-defined constants have been
  3361 replaced by polymorphic versions (INCOMPATIBILITY):
  3362 
  3363   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3364 
  3365   starset      <-- starsetNat, starsetC
  3366   *s*          <-- *sNat*, *sc*
  3367   starset_n    <-- starsetNat_n, starsetC_n
  3368   *sn*         <-- *sNatn*, *scn*
  3369   InternalSets <-- InternalNatSets, InternalCSets
  3370 
  3371   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3372   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3373   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3374   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3375   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3376 
  3377 * Hyperreal: Many type-specific theorems have been removed in favor of
  3378 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3379 
  3380   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3381   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3382   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3383   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3384   right_minus <-- hypreal_add_minus
  3385   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3386   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3387   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3388   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3389   mult_1_right <-- hcomplex_mult_one_right
  3390   mult_zero_left <-- hcomplex_mult_zero_left
  3391   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3392   right_distrib <-- hypnat_add_mult_distrib2
  3393   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3394   right_inverse <-- hypreal_mult_inverse
  3395   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3396   order_refl <-- {hypreal,hypnat}_le_refl
  3397   order_trans <-- {hypreal,hypnat}_le_trans
  3398   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3399   order_less_le <-- {hypreal,hypnat}_less_le
  3400   linorder_linear <-- {hypreal,hypnat}_le_linear
  3401   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3402   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3403   add_nonneg_nonneg <-- hypreal_le_add_order
  3404 
  3405 * Hyperreal: Separate theorems having to do with type-specific
  3406 versions of constants have been merged into theorems that apply to the
  3407 new polymorphic constants (INCOMPATIBILITY):
  3408 
  3409   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3410   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3411   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3412   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3413   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3414   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3415   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3416   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3417   STAR_diff <-- {STAR,STARC}_diff
  3418   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3419     STARC_hcomplex_of_complex}_image_subset
  3420   starset_n_Un <-- starset{Nat,C}_n_Un
  3421   starset_n_Int <-- starset{Nat,C}_n_Int
  3422   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3423   starset_n_diff <-- starset{Nat,C}_n_diff
  3424   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3425   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3426   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3427   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3428   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3429   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3430   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3431   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3432   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3433   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3434   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3435   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3436   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3437   starfun_diff <-- starfun{C,RC,CR}_diff
  3438   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3439   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3440   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3441   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3442   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3443   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3444   starfun_Id <-- starfunC_Id
  3445   starfun_approx <-- starfun{Nat,CR}_approx
  3446   starfun_capprox <-- starfun{C,RC}_capprox
  3447   starfun_abs <-- starfunNat_rabs
  3448   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3449   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3450   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3451   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3452   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3453   starfun_add_approx <-- starfunCR_add_approx
  3454   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3455   starfun_divide <-- starfun{C,CR,RC}_divide
  3456   starfun_n <-- starfun{Nat,C}_n
  3457   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3458   starfun_n_add <-- starfun{Nat,C}_n_add
  3459   starfun_n_add_minus <-- starfunNat_n_add_minus
  3460   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3461   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3462   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3463 
  3464   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3465   star_n_minus <-- {hypreal,hcomplex}_minus
  3466   star_n_diff <-- {hypreal,hcomplex}_diff
  3467   star_n_mult <-- {hypreal,hcomplex}_mult
  3468   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3469   star_n_le <-- {hypreal,hypnat}_le
  3470   star_n_less <-- {hypreal,hypnat}_less
  3471   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3472   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3473   star_n_abs <-- hypreal_hrabs
  3474   star_n_divide <-- hcomplex_divide
  3475 
  3476   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3477   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3478   star_of_diff <-- hypreal_of_real_diff
  3479   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3480   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3481   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3482   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3483   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3484   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3485   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3486   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3487   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3488   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3489   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3490   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3491   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3492   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3493   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3494   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3495   star_of_power <-- hypreal_of_real_power
  3496   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3497 
  3498 * Hyperreal: new method "transfer" that implements the transfer
  3499 principle of nonstandard analysis. With a subgoal that mentions
  3500 nonstandard types like "'a star", the command "apply transfer"
  3501 replaces it with an equivalent one that mentions only standard types.
  3502 To be successful, all free variables must have standard types; non-
  3503 standard variables must have explicit universal quantifiers.
  3504 
  3505 * Hyperreal: A theory of Taylor series.
  3506 
  3507 
  3508 *** HOLCF ***
  3509 
  3510 * Discontinued special version of 'constdefs' (which used to support
  3511 continuous functions) in favor of the general Pure one with full
  3512 type-inference.
  3513 
  3514 * New simplification procedure for solving continuity conditions; it
  3515 is much faster on terms with many nested lambda abstractions (cubic
  3516 instead of exponential time).
  3517 
  3518 * New syntax for domain package: selector names are now optional.
  3519 Parentheses should be omitted unless argument is lazy, for example:
  3520 
  3521   domain 'a stream = cons "'a" (lazy "'a stream")
  3522 
  3523 * New command 'fixrec' for defining recursive functions with pattern
  3524 matching; defining multiple functions with mutual recursion is also
  3525 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3526 sinr, or any data constructor defined by the domain package. The given
  3527 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3528 syntax and examples.
  3529 
  3530 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3531 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3532 but the proof obligation additionally includes an admissibility
  3533 requirement. The packages generate instances of class cpo or pcpo,
  3534 with continuity and strictness theorems for Rep and Abs.
  3535 
  3536 * HOLCF: Many theorems have been renamed according to a more standard naming
  3537 scheme (INCOMPATIBILITY):
  3538 
  3539   foo_inject:  "foo$x = foo$y ==> x = y"
  3540   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3541   foo_less:    "(foo$x << foo$y) = (x << y)"
  3542   foo_strict:  "foo$UU = UU"
  3543   foo_defined: "... ==> foo$x ~= UU"
  3544   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3545 
  3546 
  3547 *** ZF ***
  3548 
  3549 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3550 including the First Isomorphism Theorem (on quotienting by the kernel
  3551 of a homomorphism).
  3552 
  3553 * ZF/Simplifier: install second copy of type solver that actually
  3554 makes use of TC rules declared to Isar proof contexts (or locales);
  3555 the old version is still required for ML proof scripts.
  3556 
  3557 
  3558 *** Cube ***
  3559 
  3560 * Converted to Isar theory format; use locales instead of axiomatic
  3561 theories.
  3562 
  3563 
  3564 *** ML ***
  3565 
  3566 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3567 for ||>, ||>>, |>>,
  3568 
  3569 * Pure/library.ML no longer defines its own option datatype, but uses
  3570 that of the SML basis, which has constructors NONE and SOME instead of
  3571 None and Some, as well as exception Option.Option instead of OPTION.
  3572 The functions the, if_none, is_some, is_none have been adapted
  3573 accordingly, while Option.map replaces apsome.
  3574 
  3575 * Pure/library.ML: the exception LIST has been given up in favour of
  3576 the standard exceptions Empty and Subscript, as well as
  3577 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3578 superceded by the standard hd and tl functions etc.
  3579 
  3580 A number of basic list functions are no longer exported to the ML
  3581 toplevel, as they are variants of predefined functions.  The following
  3582 suggests how one can translate existing code:
  3583 
  3584     rev_append xs ys = List.revAppend (xs, ys)
  3585     nth_elem (i, xs) = List.nth (xs, i)
  3586     last_elem xs = List.last xs
  3587     flat xss = List.concat xss
  3588     seq fs = List.app fs
  3589     partition P xs = List.partition P xs
  3590     mapfilter f xs = List.mapPartial f xs
  3591 
  3592 * Pure/library.ML: several combinators for linear functional
  3593 transformations, notably reverse application and composition:
  3594 
  3595   x |> f                f #> g
  3596   (x, y) |-> f          f #-> g
  3597 
  3598 * Pure/library.ML: introduced/changed precedence of infix operators:
  3599 
  3600   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3601   infix 2 ?;
  3602   infix 3 o oo ooo oooo;
  3603   infix 4 ~~ upto downto;
  3604 
  3605 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3606 infix operators.
  3607 
  3608 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3609 fold_map support linear functional transformations and nesting.  For
  3610 example:
  3611 
  3612   fold f [x1, ..., xN] y =
  3613     y |> f x1 |> ... |> f xN
  3614 
  3615   (fold o fold) f [xs1, ..., xsN] y =
  3616     y |> fold f xs1 |> ... |> fold f xsN
  3617 
  3618   fold f [x1, ..., xN] =
  3619     f x1 #> ... #> f xN
  3620 
  3621   (fold o fold) f [xs1, ..., xsN] =
  3622     fold f xs1 #> ... #> fold f xsN
  3623 
  3624 * Pure/library.ML: the following selectors on type 'a option are
  3625 available:
  3626 
  3627   the:               'a option -> 'a  (*partial*)
  3628   these:             'a option -> 'a  where 'a = 'b list
  3629   the_default: 'a -> 'a option -> 'a
  3630   the_list:          'a option -> 'a list
  3631 
  3632 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3633 basic operations for association lists, following natural argument
  3634 order; moreover the explicit equality predicate passed here avoids
  3635 potentially expensive polymorphic runtime equality checks.
  3636 The old functions may be expressed as follows:
  3637 
  3638   assoc = uncurry (AList.lookup (op =))
  3639   assocs = these oo AList.lookup (op =)
  3640   overwrite = uncurry (AList.update (op =)) o swap
  3641 
  3642 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3643 
  3644   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3645   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3646 
  3647 replacing make_keylist and keyfilter (occassionally used)
  3648 Naive rewrites:
  3649 
  3650   make_keylist = AList.make
  3651   keyfilter = AList.find (op =)
  3652 
  3653 * eq_fst and eq_snd now take explicit equality parameter, thus
  3654   avoiding eqtypes. Naive rewrites:
  3655 
  3656     eq_fst = eq_fst (op =)
  3657     eq_snd = eq_snd (op =)
  3658 
  3659 * Removed deprecated apl and apr (rarely used).
  3660   Naive rewrites:
  3661 
  3662     apl (n, op) =>>= curry op n
  3663     apr (op, m) =>>= fn n => op (n, m)
  3664 
  3665 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3666 provides a reasonably efficient light-weight implementation of sets as
  3667 lists.
  3668 
  3669 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3670 few new operations; existing lookup and update are now curried to
  3671 follow natural argument order (for use with fold etc.);
  3672 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3673 
  3674 * Pure/General: output via the Isabelle channels of
  3675 writeln/warning/error etc. is now passed through Output.output, with a
  3676 hook for arbitrary transformations depending on the print_mode
  3677 (cf. Output.add_mode -- the first active mode that provides a output
  3678 function wins).  Already formatted output may be embedded into further
  3679 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3680 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3681 accommodate easy composition of diagnostic messages etc.  Programmers
  3682 rarely need to care about Output.output or Output.raw at all, with
  3683 some notable exceptions: Output.output is required when bypassing the
  3684 standard channels (writeln etc.), or in token translations to produce
  3685 properly formatted results; Output.raw is required when capturing
  3686 already output material that will eventually be presented to the user
  3687 a second time.  For the default print mode, both Output.output and
  3688 Output.raw have no effect.
  3689 
  3690 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3691 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3692 cumulative results are displayed at the end of a batch session.
  3693 
  3694 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3695 replaced by File.platform_path and File.shell_path (with appropriate
  3696 hooks).  This provides a clean interface for unusual systems where the
  3697 internal and external process view of file names are different.
  3698 
  3699 * Pure: more efficient orders for basic syntactic entities: added
  3700 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3701 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3702 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3703 orders now -- potential INCOMPATIBILITY for code that depends on a
  3704 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3705 Library.sort_strings on result).
  3706 
  3707 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3708 fold_types traverse types/terms from left to right, observing natural
  3709 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3710 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3711 
  3712 * Pure: name spaces have been refined, with significant changes of the
  3713 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3714 to extern(_table).  The plain name entry path is superceded by a
  3715 general 'naming' context, which also includes the 'policy' to produce
  3716 a fully qualified name and external accesses of a fully qualified
  3717 name; NameSpace.extend is superceded by context dependent
  3718 Sign.declare_name.  Several theory and proof context operations modify
  3719 the naming context.  Especially note Theory.restore_naming and
  3720 ProofContext.restore_naming to get back to a sane state; note that
  3721 Theory.add_path is no longer sufficient to recover from
  3722 Theory.absolute_path in particular.
  3723 
  3724 * Pure: new flags short_names (default false) and unique_names
  3725 (default true) for controlling output of qualified names.  If
  3726 short_names is set, names are printed unqualified.  If unique_names is
  3727 reset, the name prefix is reduced to the minimum required to achieve
  3728 the original result when interning again, even if there is an overlap
  3729 with earlier declarations.
  3730 
  3731 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3732 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3733 (useful for printing error messages).  INCOMPATIBILITY.
  3734 
  3735 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3736 Theory.theory are now identified, referring to the universal
  3737 Context.theory (see Pure/context.ML).  Actual signature and theory
  3738 content is managed as theory data.  The old code and interfaces were
  3739 spread over many files and structures; the new arrangement introduces
  3740 considerable INCOMPATIBILITY to gain more clarity:
  3741 
  3742   Context -- theory management operations (name, identity, inclusion,
  3743     parents, ancestors, merge, etc.), plus generic theory data;
  3744 
  3745   Sign -- logical signature and syntax operations (declaring consts,
  3746     types, etc.), plus certify/read for common entities;
  3747 
  3748   Theory -- logical theory operations (stating axioms, definitions,
  3749     oracles), plus a copy of logical signature operations (consts,
  3750     types, etc.); also a few basic management operations (Theory.copy,
  3751     Theory.merge, etc.)
  3752 
  3753 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3754 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3755 for convenience -- they merely return the theory.
  3756 
  3757 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3758 
  3759 * Pure: the Isar proof context type is already defined early in Pure
  3760 as Context.proof (note that ProofContext.context and Proof.context are
  3761 aliases, where the latter is the preferred name).  This enables other
  3762 Isabelle components to refer to that type even before Isar is present.
  3763 
  3764 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3765 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3766 any of these kinds.  For example, Sign.intern typeK is now
  3767 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3768 Theory.hide_types.  Also note that former
  3769 Theory.hide_classes/types/consts are now
  3770 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3771 internalize their arguments!  INCOMPATIBILITY.
  3772 
  3773 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3774 datatype thmref (with constructors Name and NameSelection) instead of
  3775 plain string -- INCOMPATIBILITY;
  3776 
  3777 * Pure: cases produced by proof methods specify options, where NONE
  3778 means to remove case bindings -- INCOMPATIBILITY in
  3779 (RAW_)METHOD_CASES.
  3780 
  3781 * Pure: the following operations retrieve axioms or theorems from a
  3782 theory node or theory hierarchy, respectively:
  3783 
  3784   Theory.axioms_of: theory -> (string * term) list
  3785   Theory.all_axioms_of: theory -> (string * term) list
  3786   PureThy.thms_of: theory -> (string * thm) list
  3787   PureThy.all_thms_of: theory -> (string * thm) list
  3788 
  3789 * Pure: print_tac now outputs the goal through the trace channel.
  3790 
  3791 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3792 Reference Toplevel.debug (default false) controls detailed printing
  3793 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3794 controls execution profiling -- set to 1 for time and 2 for space
  3795 (both increase the runtime).
  3796 
  3797 * Isar session: The initial use of ROOT.ML is now always timed,
  3798 i.e. the log will show the actual process times, in contrast to the
  3799 elapsed wall-clock time that the outer shell wrapper produces.
  3800 
  3801 * Simplifier: improved handling of bound variables (nameless
  3802 representation, avoid allocating new strings).  Simprocs that invoke
  3803 the Simplifier recursively should use Simplifier.inherit_bounds to
  3804 avoid local name clashes.  Failure to do so produces warnings
  3805 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3806 for further details.
  3807 
  3808 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3809 bindings for all theorems stored within a given theory; this may help
  3810 in porting non-Isar theories to Isar ones, while keeping ML proof
  3811 scripts for the time being.
  3812 
  3813 * ML operator HTML.with_charset specifies the charset begin used for
  3814 generated HTML files.  For example:
  3815 
  3816   HTML.with_charset "utf-8" use_thy "Hebrew";
  3817   HTML.with_charset "utf-8" use_thy "Chinese";
  3818 
  3819 
  3820 *** System ***
  3821 
  3822 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3823 isabelle, isatool etc.).
  3824 
  3825 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3826 isatool doc, isatool mkdir, display_drafts etc.).
  3827 
  3828 * isatool usedir: option -f allows specification of the ML file to be
  3829 used by Isabelle; default is ROOT.ML.
  3830 
  3831 * New isatool version outputs the version identifier of the Isabelle
  3832 distribution being used.
  3833 
  3834 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3835 (containing Boolean satisfiability problems) into Isabelle/HOL
  3836 theories.
  3837 
  3838 
  3839 
  3840 New in Isabelle2004 (April 2004)
  3841 --------------------------------
  3842 
  3843 *** General ***
  3844 
  3845 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3846   Replaces linorder.ML.
  3847 
  3848 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3849   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3850   (\<a>...\<z>), are now considered normal letters, and can therefore
  3851   be used anywhere where an ASCII letter (a...zA...Z) has until
  3852   now. COMPATIBILITY: This obviously changes the parsing of some
  3853   terms, especially where a symbol has been used as a binder, say
  3854   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3855   as an identifier.  Fix it by inserting a space around former
  3856   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3857   existing theory and ML files.
  3858 
  3859 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3860 
  3861 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3862   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3863   a normal (but invisible) letter. For multiple letter subscripts repeat
  3864   \<^isub> like this: x\<^isub>1\<^isub>2.
  3865 
  3866 * Pure: There are now sub-/superscripts that can span more than one
  3867   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3868   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3869   superscript. The new control characters are not identifier parts.
  3870 
  3871 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3872   content of "..." to the latex file instead of \isacntrl... . The "..."
  3873   may consist of any printable characters excluding the end bracket >.
  3874 
  3875 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3876   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3877   declare constants "final", which prevents their being given a definition
  3878   later.  It is useful for constants whose behaviour is fixed axiomatically
  3879   rather than definitionally, such as the meta-logic connectives.
  3880 
  3881 * Pure: 'instance' now handles general arities with general sorts
  3882   (i.e. intersections of classes),
  3883 
  3884 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3885   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3886   It can be changed to alter the colors/layout of generated pages.
  3887 
  3888 
  3889 *** Isar ***
  3890 
  3891 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3892   cut_tac, subgoal_tac and thin_tac:
  3893   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3894     locales are no longer forced to write Isar proof scripts.
  3895     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3896     emulations.
  3897   - INCOMPATIBILITY: names of variables to be instantiated may no
  3898     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3899     This is consistent with the instantiation attribute "where".
  3900 
  3901 * Attributes "where" and "of":
  3902   - Now take type variables of instantiated theorem into account when reading
  3903     the instantiation string.  This fixes a bug that caused instantiated
  3904     theorems to have too special types in some circumstances.
  3905   - "where" permits explicit instantiations of type variables.
  3906 
  3907 * Calculation commands "moreover" and "also" no longer interfere with
  3908   current facts ("this"), admitting arbitrary combinations with "then"
  3909   and derived forms.
  3910 
  3911 * Locales:
  3912   - Goal statements involving the context element "includes" no longer
  3913     generate theorems with internal delta predicates (those ending on
  3914     "_axioms") in the premise.
  3915     Resolve particular premise with <locale>.intro to obtain old form.
  3916   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3917     specification and "includes" elements in goal statement.
  3918   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3919     [intro?] and [elim?] (respectively) by default.
  3920   - Experimental command for instantiation of locales in proof contexts:
  3921         instantiate <label>[<attrs>]: <loc>
  3922     Instantiates locale <loc> and adds all its theorems to the current context
  3923     taking into account their attributes.  Label and attrs are optional
  3924     modifiers, like in theorem declarations.  If present, names of
  3925     instantiated theorems are qualified with <label>, and the attributes
  3926     <attrs> are applied after any attributes these theorems might have already.
  3927       If the locale has assumptions, a chained fact of the form
  3928     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3929     are derived.  The command does not support old-style locales declared
  3930     with "locale (open)".
  3931       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3932 
  3933 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3934   (Isar) contexts.
  3935 
  3936 
  3937 *** HOL ***
  3938 
  3939 * Proof import: new image HOL4 contains the imported library from
  3940   the HOL4 system with about 2500 theorems. It is imported by
  3941   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3942   can be used like any other Isabelle image.  See
  3943   HOL/Import/HOL/README for more information.
  3944 
  3945 * Simplifier:
  3946   - Much improved handling of linear and partial orders.
  3947     Reasoners for linear and partial orders are set up for type classes
  3948     "linorder" and "order" respectively, and are added to the default simpset
  3949     as solvers.  This means that the simplifier can build transitivity chains
  3950     to solve goals from the assumptions.
  3951   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3952     of blast or auto after simplification become unnecessary because the goal
  3953     is solved by simplification already.
  3954 
  3955 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3956     all proved in axiomatic type classes for semirings, rings and fields.
  3957 
  3958 * Numerics:
  3959   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3960     now formalized using the Ring_and_Field theory mentioned above.
  3961   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3962     than before, because now they are set up once in a generic manner.
  3963   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3964     Look for the general versions in Ring_and_Field (and Power if they concern
  3965     exponentiation).
  3966 
  3967 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3968 
  3969 * Records:
  3970   - Record types are now by default printed with their type abbreviation
  3971     instead of the list of all field types. This can be configured via
  3972     the reference "print_record_type_abbr".
  3973   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3974     (not enabled by default).
  3975   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3976     EX x. x = sel r to True (not enabled by default).
  3977   - Tactic "record_split_simp_tac" to split and simplify records added.
  3978 
  3979 * 'specification' command added, allowing for definition by
  3980   specification.  There is also an 'ax_specification' command that
  3981   introduces the new constants axiomatically.
  3982 
  3983 * arith(_tac) is now able to generate counterexamples for reals as well.
  3984 
  3985 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3986 
  3987 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3988   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3989 
  3990 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3991   matrix theory to linear programming.
  3992 
  3993 * Unions and Intersections:
  3994   The latex output syntax of UN and INT has been changed
  3995   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3996   i.e. the index formulae has become a subscript.
  3997   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3998 
  3999 * Unions and Intersections over Intervals:
  4000   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4001   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4002   like in normal math, and corresponding versions for < and for intersection.
  4003 
  4004 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4005   lexicographic dictonary ordering has been added as "lexord".
  4006 
  4007 * ML: the legacy theory structures Int and List have been removed. They had
  4008   conflicted with ML Basis Library structures having the same names.
  4009 
  4010 * 'refute' command added to search for (finite) countermodels.  Only works
  4011   for a fragment of HOL.  The installation of an external SAT solver is
  4012   highly recommended.  See "HOL/Refute.thy" for details.
  4013 
  4014 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4015   formulae under an assignment of free variables to random values.
  4016   In contrast to 'refute', it can deal with inductive datatypes,
  4017   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4018   for examples.
  4019 
  4020 
  4021 *** HOLCF ***
  4022 
  4023 * Streams now come with concatenation and are part of the HOLCF image
  4024 
  4025 
  4026 
  4027 New in Isabelle2003 (May 2003)
  4028 ------------------------------
  4029 
  4030 *** General ***
  4031 
  4032 * Provers/simplifier:
  4033 
  4034   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4035     Assumptions are now subject to complete mutual simplification,
  4036     not just from left to right. The simplifier now preserves
  4037     the order of assumptions.
  4038 
  4039     Potential INCOMPATIBILITY:
  4040 
  4041     -- simp sometimes diverges where the old version did
  4042        not, e.g. invoking simp on the goal
  4043 
  4044         [| P (f x); y = x; f x = f y |] ==> Q
  4045 
  4046        now gives rise to the infinite reduction sequence
  4047 
  4048         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4049 
  4050        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4051        kind of problem.
  4052 
  4053     -- Tactics combining classical reasoner and simplification (such as auto)
  4054        are also affected by this change, because many of them rely on
  4055        simp. They may sometimes diverge as well or yield a different numbers
  4056        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4057        in case of problems. Sometimes subsequent calls to the classical
  4058        reasoner will fail because a preceeding call to the simplifier too
  4059        eagerly simplified the goal, e.g. deleted redundant premises.
  4060 
  4061   - The simplifier trace now shows the names of the applied rewrite rules
  4062 
  4063   - You can limit the number of recursive invocations of the simplifier
  4064     during conditional rewriting (where the simplifie tries to solve the
  4065     conditions before applying the rewrite rule):
  4066     ML "simp_depth_limit := n"
  4067     where n is an integer. Thus you can force termination where previously
  4068     the simplifier would diverge.
  4069 
  4070   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4071 
  4072   - No longer aborts on failed congruence proof.  Instead, the
  4073     congruence is ignored.
  4074 
  4075 * Pure: New generic framework for extracting programs from constructive
  4076   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4077   as HOL/Extraction for some case studies.
  4078 
  4079 * Pure: The main goal of the proof state is no longer shown by default, only
  4080 the subgoals. This behaviour is controlled by a new flag.
  4081    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4082 (ML: Proof.show_main_goal).
  4083 
  4084 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4085 rules whose conclusion matches subgoal 1:
  4086       PG menu: Isabelle/Isar -> Show me -> matching rules
  4087 The rules are ordered by how closely they match the subgoal.
  4088 In particular, rules that solve a subgoal outright are displayed first
  4089 (or rather last, the way they are printed).
  4090 (ML: ProofGeneral.print_intros())
  4091 
  4092 * Pure: New flag trace_unify_fail causes unification to print
  4093 diagnostic information (PG: in trace buffer) when it fails. This is
  4094 useful for figuring out why single step proofs like rule, erule or
  4095 assumption failed.
  4096 
  4097 * Pure: Locale specifications now produce predicate definitions
  4098 according to the body of text (covering assumptions modulo local
  4099 definitions); predicate "loc_axioms" covers newly introduced text,
  4100 while "loc" is cumulative wrt. all included locale expressions; the
  4101 latter view is presented only on export into the global theory
  4102 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4103 on the old view without predicates;
  4104 
  4105 * Pure: predefined locales "var" and "struct" are useful for sharing
  4106 parameters (as in CASL, for example); just specify something like
  4107 ``var x + var y + struct M'' as import;
  4108 
  4109 * Pure: improved thms_containing: proper indexing of facts instead of
  4110 raw theorems; check validity of results wrt. current name space;
  4111 include local facts of proof configuration (also covers active
  4112 locales), cover fixed variables in index; may use "_" in term
  4113 specification; an optional limit for the number of printed facts may
  4114 be given (the default is 40);
  4115 
  4116 * Pure: disallow duplicate fact bindings within new-style theory files
  4117 (batch-mode only);
  4118 
  4119 * Provers: improved induct method: assumptions introduced by case
  4120 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4121 the goal statement); "foo" still refers to all facts collectively;
  4122 
  4123 * Provers: the function blast.overloaded has been removed: all constants
  4124 are regarded as potentially overloaded, which improves robustness in exchange
  4125 for slight decrease in efficiency;
  4126 
  4127 * Provers/linorder: New generic prover for transitivity reasoning over
  4128 linear orders.  Note: this prover is not efficient!
  4129 
  4130 * Isar: preview of problems to finish 'show' now produce an error
  4131 rather than just a warning (in interactive mode);
  4132 
  4133 
  4134 *** HOL ***
  4135 
  4136 * arith(_tac)
  4137 
  4138  - Produces a counter example if it cannot prove a goal.
  4139    Note that the counter example may be spurious if the goal is not a formula
  4140    of quantifier-free linear arithmetic.
  4141    In ProofGeneral the counter example appears in the trace buffer.
  4142 
  4143  - Knows about div k and mod k where k is a numeral of type nat or int.
  4144 
  4145  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4146    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4147    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4148 
  4149 * simp's arithmetic capabilities have been enhanced a bit: it now
  4150 takes ~= in premises into account (by performing a case split);
  4151 
  4152 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4153 are distributed over a sum of terms;
  4154 
  4155 * New tactic "trans_tac" and method "trans" instantiate
  4156 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4157 "<=", "<" and "=").
  4158 
  4159 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4160 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4161 
  4162 * 'typedef' command has new option "open" to suppress the set
  4163 definition;
  4164 
  4165 * functions Min and Max on finite sets have been introduced (theory
  4166 Finite_Set);
  4167 
  4168 * attribute [symmetric] now works for relations as well; it turns
  4169 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4170 
  4171 * induct over a !!-quantified statement (say !!x1..xn):
  4172   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4173 
  4174 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4175 %x. None. Warning: empty_def now refers to the previously hidden definition
  4176 of the empty set.
  4177 
  4178 * Algebra: formalization of classical algebra.  Intended as base for
  4179 any algebraic development in Isabelle.  Currently covers group theory
  4180 (up to Sylow's theorem) and ring theory (Universal Property of
  4181 Univariate Polynomials).  Contributions welcome;
  4182 
  4183 * GroupTheory: deleted, since its material has been moved to Algebra;
  4184 
  4185 * Complex: new directory of the complex numbers with numeric constants,
  4186 nonstandard complex numbers, and some complex analysis, standard and
  4187 nonstandard (Jacques Fleuriot);
  4188 
  4189 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4190 
  4191 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4192 Fleuriot);
  4193 
  4194 * Real/HahnBanach: updated and adapted to locales;
  4195 
  4196 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4197 Gray and Kramer);
  4198 
  4199 * UNITY: added the Meier-Sanders theory of progress sets;
  4200 
  4201 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4202 as abstract algorithms, instantiated to the JVM;
  4203 
  4204 * Bali: Java source language formalization. Type system, operational
  4205 semantics, axiomatic semantics. Supported language features:
  4206 classes, interfaces, objects,virtual methods, static methods,
  4207 static/instance fields, arrays, access modifiers, definite
  4208 assignment, exceptions.
  4209 
  4210 
  4211 *** ZF ***
  4212 
  4213 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4214 universe, etc.);
  4215 
  4216 * Main ZF: virtually all theories converted to new-style format;
  4217 
  4218 
  4219 *** ML ***
  4220 
  4221 * Pure: Tactic.prove provides sane interface for internal proofs;
  4222 omits the infamous "standard" operation, so this is more appropriate
  4223 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4224 
  4225 * Pure: improved error reporting of simprocs;
  4226 
  4227 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4228 up simprocs;
  4229 
  4230 
  4231 *** Document preparation ***
  4232 
  4233 * uses \par instead of \\ for line breaks in theory text. This may
  4234 shift some page breaks in large documents. To get the old behaviour
  4235 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4236 
  4237 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4238 other packages
  4239 
  4240 * \<euro> now needs package babel/greek instead of marvosym (which
  4241 broke \Rightarrow)
  4242 
  4243 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4244 textcomp package)
  4245 
  4246 
  4247 
  4248 New in Isabelle2002 (March 2002)
  4249 --------------------------------
  4250 
  4251 *** Document preparation ***
  4252 
  4253 * greatly simplified document preparation setup, including more
  4254 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4255 instructive isatool mkdir; users should basically be able to get
  4256 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4257 users may run a separate document processing stage manually like this:
  4258 "isatool usedir -D output HOL Test && isatool document Test/output";
  4259 
  4260 * theory dependency graph may now be incorporated into documents;
  4261 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4262 with \includegraphics of LaTeX;
  4263 
  4264 * proper spacing of consecutive markup elements, especially text
  4265 blocks after section headings;
  4266 
  4267 * support bold style (for single symbols only), input syntax is like
  4268 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4269 
  4270 * \<bullet> is now output as bold \cdot by default, which looks much
  4271 better in printed text;
  4272 
  4273 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4274 note that these symbols are currently unavailable in Proof General /
  4275 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4276 
  4277 * isatool latex no longer depends on changed TEXINPUTS, instead
  4278 isatool document copies the Isabelle style files to the target
  4279 location;
  4280 
  4281 
  4282 *** Isar ***
  4283 
  4284 * Pure/Provers: improved proof by cases and induction;
  4285   - 'case' command admits impromptu naming of parameters (such as
  4286     "case (Suc n)");
  4287   - 'induct' method divinates rule instantiation from the inductive
  4288     claim; no longer requires excessive ?P bindings for proper
  4289     instantiation of cases;
  4290   - 'induct' method properly enumerates all possibilities of set/type
  4291     rules; as a consequence facts may be also passed through *type*
  4292     rules without further ado;
  4293   - 'induct' method now derives symbolic cases from the *rulified*
  4294     rule (before it used to rulify cases stemming from the internal
  4295     atomized version); this means that the context of a non-atomic
  4296     statement becomes is included in the hypothesis, avoiding the
  4297     slightly cumbersome show "PROP ?case" form;
  4298   - 'induct' may now use elim-style induction rules without chaining
  4299     facts, using ``missing'' premises from the goal state; this allows
  4300     rules stemming from inductive sets to be applied in unstructured
  4301     scripts, while still benefitting from proper handling of non-atomic
  4302     statements; NB: major inductive premises need to be put first, all
  4303     the rest of the goal is passed through the induction;
  4304   - 'induct' proper support for mutual induction involving non-atomic
  4305     rule statements (uses the new concept of simultaneous goals, see
  4306     below);
  4307   - append all possible rule selections, but only use the first
  4308     success (no backtracking);
  4309   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4310   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4311   - added 'print_induct_rules' (covered by help item in recent Proof
  4312     General versions);
  4313   - moved induct/cases attributes to Pure, methods to Provers;
  4314   - generic method setup instantiated for FOL and HOL;
  4315 
  4316 * Pure: support multiple simultaneous goal statements, for example
  4317 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4318 meta-level mechanism, this acts as if several individual goals had
  4319 been stated separately; in particular common proof methods need to be
  4320 repeated in order to cover all claims; note that a single elimination
  4321 step is *not* sufficient to establish the two conjunctions, so this
  4322 fails:
  4323 
  4324   assume "A & B" then have A and B ..   (*".." fails*)
  4325 
  4326 better use "obtain" in situations as above; alternative refer to
  4327 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4328 
  4329 * Pure: proper integration with ``locales''; unlike the original
  4330 version by Florian Kammller, Isar locales package high-level proof
  4331 contexts rather than raw logical ones (e.g. we admit to include
  4332 attributes everywhere); operations on locales include merge and
  4333 rename; support for implicit arguments (``structures''); simultaneous
  4334 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4335 some examples;
  4336 
  4337 * Pure: the following commands have been ``localized'', supporting a
  4338 target locale specification "(in name)": 'lemma', 'theorem',
  4339 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4340 stored both within the locale and at the theory level (exported and
  4341 qualified by the locale name);
  4342 
  4343 * Pure: theory goals may now be specified in ``long'' form, with
  4344 ad-hoc contexts consisting of arbitrary locale elements. for example
  4345 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4346 definitions may be given, too); the result is a meta-level rule with
  4347 the context elements being discharged in the obvious way;
  4348 
  4349 * Pure: new proof command 'using' allows to augment currently used
  4350 facts after a goal statement ('using' is syntactically analogous to
  4351 'apply', but acts on the goal's facts only); this allows chained facts
  4352 to be separated into parts given before and after a claim, as in
  4353 ``from a and b have C using d and e <proof>'';
  4354 
  4355 * Pure: renamed "antecedent" case to "rule_context";
  4356 
  4357 * Pure: new 'judgment' command records explicit information about the
  4358 object-logic embedding (used by several tools internally); no longer
  4359 use hard-wired "Trueprop";
  4360 
  4361 * Pure: added 'corollary' command;
  4362 
  4363 * Pure: fixed 'token_translation' command;
  4364 
  4365 * Pure: removed obsolete 'exported' attribute;
  4366 
  4367 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4368 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4369 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4370 
  4371 * Pure: method 'atomize' presents local goal premises as object-level
  4372 statements (atomic meta-level propositions); setup controlled via
  4373 rewrite rules declarations of 'atomize' attribute; example
  4374 application: 'induct' method with proper rule statements in improper
  4375 proof *scripts*;
  4376 
  4377 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4378 now consider the syntactic context of assumptions, giving a better
  4379 chance to get type-inference of the arguments right (this is
  4380 especially important for locales);
  4381 
  4382 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4383 mode;
  4384 
  4385 * Pure/obtain: the formal conclusion "thesis", being marked as
  4386 ``internal'', may no longer be reference directly in the text;
  4387 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4388 situations;
  4389 
  4390 * Pure: generic 'sym' attribute which declares a rule both as pure
  4391 'elim?' and for the 'symmetric' operation;
  4392 
  4393 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4394 text; the fixed correlation with particular command syntax has been
  4395 discontinued;
  4396 
  4397 * Pure: new method 'rules' is particularly well-suited for proof
  4398 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4399 but often produces more compact proof terms with less detours;
  4400 
  4401 * Pure/Provers/classical: simplified integration with pure rule
  4402 attributes and methods; the classical "intro?/elim?/dest?"
  4403 declarations coincide with the pure ones; the "rule" method no longer
  4404 includes classically swapped intros; "intro" and "elim" methods no
  4405 longer pick rules from the context; also got rid of ML declarations
  4406 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4407 INCOMPATIBILITY;
  4408 
  4409 * Provers/classical: attribute 'swapped' produces classical inversions
  4410 of introduction rules;
  4411 
  4412 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4413 rules instead of full simplifier context; 'iff' attribute handles
  4414 conditional rules;
  4415 
  4416 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4417 
  4418 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4419 "(permissive)" option to recover old behavior;
  4420 
  4421 * HOL: 'inductive' no longer features separate (collective) attributes
  4422 for 'intros' (was found too confusing);
  4423 
  4424 * HOL: properly declared induction rules less_induct and
  4425 wf_induct_rule;
  4426 
  4427 
  4428 *** HOL ***
  4429 
  4430 * HOL: moved over to sane numeral syntax; the new policy is as
  4431 follows:
  4432 
  4433   - 0 and 1 are polymorphic constants, which are defined on any
  4434   numeric type (nat, int, real etc.);
  4435 
  4436   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4437   binary representation internally;
  4438 
  4439   - type nat has special constructor Suc, and generally prefers Suc 0
  4440   over 1::nat and Suc (Suc 0) over 2::nat;
  4441 
  4442 This change may cause significant problems of INCOMPATIBILITY; here
  4443 are some hints on converting existing sources:
  4444 
  4445   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4446   entities, so expressions involving "-" (unary or binary minus) need
  4447   to be spaced properly;
  4448 
  4449   - existing occurrences of "1" may need to be constraint "1::nat" or
  4450   even replaced by Suc 0; similar for old "2";
  4451 
  4452   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4453 
  4454   - remove all special provisions on numerals in proofs;
  4455 
  4456 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4457 representation (depends on bin_arith_simps in the default context);
  4458 
  4459 * HOL: symbolic syntax for x^2 (numeral 2);
  4460 
  4461 * HOL: the class of all HOL types is now called "type" rather than
  4462 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4463 in axclass/classes, instance/arities, and (usually rare) occurrences
  4464 in typings (of consts etc.); internally the class is called
  4465 "HOL.type", ML programs should refer to HOLogic.typeS;
  4466 
  4467 * HOL/record package improvements:
  4468   - new derived operations "fields" to build a partial record section,
  4469     "extend" to promote a fixed record to a record scheme, and
  4470     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4471     declared as simp by default;
  4472   - shared operations ("more", "fields", etc.) now need to be always
  4473     qualified) --- potential INCOMPATIBILITY;
  4474   - removed "make_scheme" operations (use "make" with "extend") --
  4475     INCOMPATIBILITY;
  4476   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4477   - provides cases/induct rules for use with corresponding Isar
  4478     methods (for concrete records, record schemes, concrete more
  4479     parts, and schematic more parts -- in that order);
  4480   - internal definitions directly based on a light-weight abstract
  4481     theory of product types over typedef rather than datatype;
  4482 
  4483 * HOL: generic code generator for generating executable ML code from
  4484 specifications; specific support for HOL constructs such as inductive
  4485 datatypes and sets, as well as recursive functions; can be invoked
  4486 via 'generate_code' theory section;
  4487 
  4488 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4489 
  4490 * HOL: consolidated and renamed several theories.  In particular:
  4491         Ord.thy has been absorbed into HOL.thy
  4492         String.thy has been absorbed into List.thy
  4493 
  4494 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4495 (beware of argument permutation!);
  4496 
  4497 * HOL: linorder_less_split superseded by linorder_cases;
  4498 
  4499 * HOL/List: "nodups" renamed to "distinct";
  4500 
  4501 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4502 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4503   - Ex_def has changed, now need to use some_eq_ex
  4504 
  4505 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4506 in this (rare) case use:
  4507 
  4508   delSWrapper "split_all_tac"
  4509   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4510 
  4511 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4512 MAY FAIL;
  4513 
  4514 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4515 Isabelle's type classes, ^ on functions and relations has too general
  4516 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4517 necessary to attach explicit type constraints;
  4518 
  4519 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4520 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4521 renamed accordingly (eg "compI" -> "rel_compI").
  4522 
  4523 * HOL: syntax translations now work properly with numerals and records
  4524 expressions;
  4525 
  4526 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4527 of "lam" -- INCOMPATIBILITY;
  4528 
  4529 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4530 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4531 renamed "Product_Type.unit";
  4532 
  4533 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4534 
  4535 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4536 the "cases" method);
  4537 
  4538 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4539 Florian Kammller);
  4540 
  4541 * HOL/IMP: updated and converted to new-style theory format; several
  4542 parts turned into readable document, with proper Isar proof texts and
  4543 some explanations (by Gerwin Klein);
  4544 
  4545 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4546 
  4547 * HOL-Hyperreal is now a logic image;
  4548 
  4549 
  4550 *** HOLCF ***
  4551 
  4552 * Isar: consts/constdefs supports mixfix syntax for continuous
  4553 operations;
  4554 
  4555 * Isar: domain package adapted to new-style theory format, e.g. see
  4556 HOLCF/ex/Dnat.thy;
  4557 
  4558 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4559 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4560 lift.induct_tac, always use UU instead of Undef;
  4561 
  4562 * HOLCF/IMP: updated and converted to new-style theory;
  4563 
  4564 
  4565 *** ZF ***
  4566 
  4567 * Isar: proper integration of logic-specific tools and packages,
  4568 including theory commands '(co)inductive', '(co)datatype',
  4569 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4570 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4571 
  4572 * theory Main no longer includes AC; for the Axiom of Choice, base
  4573 your theory on Main_ZFC;
  4574 
  4575 * the integer library now covers quotients and remainders, with many
  4576 laws relating division to addition, multiplication, etc.;
  4577 
  4578 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4579 typeless version of the formalism;
  4580 
  4581 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4582 format;
  4583 
  4584 * ZF/Induct: new directory for examples of inductive definitions,
  4585 including theory Multiset for multiset orderings; converted to
  4586 new-style theory format;
  4587 
  4588 * ZF: many new theorems about lists, ordinals, etc.;
  4589 
  4590 
  4591 *** General ***
  4592 
  4593 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4594 variable proof controls level of detail: 0 = no proofs (only oracle
  4595 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4596 also ref manual for further ML interfaces;
  4597 
  4598 * Pure/axclass: removed obsolete ML interface
  4599 goal_subclass/goal_arity;
  4600 
  4601 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4602 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4603 separate tokens, so expressions involving minus need to be spaced
  4604 properly;
  4605 
  4606 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4607 rather than "infixl" or "infixr";
  4608 
  4609 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4610 sort constraint specifications in type inference; e.g. "x::_::foo"
  4611 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4612 type variable);
  4613 
  4614 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4615 control output of nested => (types); the default behavior is
  4616 "type_brackets";
  4617 
  4618 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4619 tokens into AST constants;
  4620 
  4621 * Pure/syntax: prefer later declarations of translations and print
  4622 translation functions; potential INCOMPATIBILITY: need to reverse
  4623 multiple declarations for same syntax element constant;
  4624 
  4625 * Pure/show_hyps reset by default (in accordance to existing Isar
  4626 practice);
  4627 
  4628 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4629 addSafter;
  4630 
  4631 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4632 as well;
  4633 
  4634 * system: tested support for MacOS X; should be able to get Isabelle +
  4635 Proof General to work in a plain Terminal after installing Poly/ML
  4636 (e.g. from the Isabelle distribution area) and GNU bash alone
  4637 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4638 support requires further installations, e.g. from
  4639 http://fink.sourceforge.net/);
  4640 
  4641 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4642 
  4643 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4644 of 40 MB), cf. ML_OPTIONS;
  4645 
  4646 * system: Proof General keywords specification is now part of the
  4647 Isabelle distribution (see etc/isar-keywords.el);
  4648 
  4649 * system: support for persistent Proof General sessions (refrain from
  4650 outdating all loaded theories on startup); user may create writable
  4651 logic images like this: ``isabelle -q HOL Test'';
  4652 
  4653 * system: smart selection of Isabelle process versus Isabelle
  4654 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4655 run both "isabelle" and "Isabelle" even if file names are badly
  4656 damaged (executable inspects the case of the first letter of its own
  4657 name); added separate "isabelle-process" and "isabelle-interface";
  4658 
  4659 * system: refrain from any attempt at filtering input streams; no
  4660 longer support ``8bit'' encoding of old isabelle font, instead proper
  4661 iso-latin characters may now be used; the related isatools
  4662 "symbolinput" and "nonascii" have disappeared as well;
  4663 
  4664 * system: removed old "xterm" interface (the print modes "xterm" and
  4665 "xterm_color" are still available for direct use in a suitable
  4666 terminal);
  4667 
  4668 
  4669 
  4670 New in Isabelle99-2 (February 2001)
  4671 -----------------------------------
  4672 
  4673 *** Overview of INCOMPATIBILITIES ***
  4674 
  4675 * HOL: please note that theories in the Library and elsewhere often use the
  4676 new-style (Isar) format; to refer to their theorems in an ML script you must
  4677 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4678 
  4679 * HOL: inductive package no longer splits induction rule aggressively,
  4680 but only as far as specified by the introductions given; the old
  4681 format may be recovered via ML function complete_split_rule or attribute
  4682 'split_rule (complete)';
  4683 
  4684 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4685 gfp_Tarski to gfp_unfold;
  4686 
  4687 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4688 
  4689 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4690 relation); infix "^^" has been renamed "``"; infix "``" has been
  4691 renamed "`"; "univalent" has been renamed "single_valued";
  4692 
  4693 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4694 operation;
  4695 
  4696 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4697 
  4698 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4699 
  4700 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4701 consequence, it is no longer monotonic wrt. the local goal context
  4702 (which is now passed through the inductive cases);
  4703 
  4704 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4705 \<gg> to \<ggreater>;
  4706 
  4707 
  4708 *** Document preparation ***
  4709 
  4710 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4711 available: are "it" for near math-mode best-style output, "sl" for
  4712 slanted text style, and "tt" for plain type-writer; if no
  4713 \isabellestyle command is given, output is according to slanted
  4714 type-writer);
  4715 
  4716 * support sub/super scripts (for single symbols only), input syntax is
  4717 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4718 
  4719 * some more standard symbols; see Appendix A of the system manual for
  4720 the complete list of symbols defined in isabellesym.sty;
  4721 
  4722 * improved isabelle style files; more abstract symbol implementation
  4723 (should now use \isamath{...} and \isatext{...} in custom symbol
  4724 definitions);
  4725 
  4726 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4727 state; Note that presentation of goal states does not conform to
  4728 actual human-readable proof documents.  Please do not include goal
  4729 states into document output unless you really know what you are doing!
  4730 
  4731 * proper indentation of antiquoted output with proportional LaTeX
  4732 fonts;
  4733 
  4734 * no_document ML operator temporarily disables LaTeX document
  4735 generation;
  4736 
  4737 * isatool unsymbolize tunes sources for plain ASCII communication;
  4738 
  4739 
  4740 *** Isar ***
  4741 
  4742 * Pure: Isar now suffers initial goal statements to contain unbound
  4743 schematic variables (this does not conform to actual readable proof
  4744 documents, due to unpredictable outcome and non-compositional proof
  4745 checking); users who know what they are doing may use schematic goals
  4746 for Prolog-style synthesis of proven results;
  4747 
  4748 * Pure: assumption method (an implicit finishing) now handles actual
  4749 rules as well;
  4750 
  4751 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4752 initial goal, declare "that" only as Pure intro (only for single
  4753 steps); the "that" rule assumption may now be involved in implicit
  4754 finishing, thus ".." becomes a feasible for trivial obtains;
  4755 
  4756 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4757 instance proofs may be performed by "..";
  4758 
  4759 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4760 statements as well;
  4761 
  4762 * Pure: more robust selection of calculational rules;
  4763 
  4764 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4765 rule (as well as the assumption rule);
  4766 
  4767 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4768 lemmas, using the graph browser tool;
  4769 
  4770 * Pure: predict failure of "show" in interactive mode;
  4771 
  4772 * Pure: 'thms_containing' now takes actual terms as arguments;
  4773 
  4774 * HOL: improved method 'induct' --- now handles non-atomic goals
  4775 (potential INCOMPATIBILITY); tuned error handling;
  4776 
  4777 * HOL: cases and induct rules now provide explicit hints about the
  4778 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4779 any remaining facts are inserted into the goal verbatim;
  4780 
  4781 * HOL: local contexts (aka cases) may now contain term bindings as
  4782 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4783 the result to be shown in each case;
  4784 
  4785 * HOL: added 'recdef_tc' command;
  4786 
  4787 * isatool convert assists in eliminating legacy ML scripts;
  4788 
  4789 
  4790 *** HOL ***
  4791 
  4792 * HOL/Library: a collection of generic theories to be used together
  4793 with main HOL; the theory loader path already includes this directory
  4794 by default; the following existing theories have been moved here:
  4795 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4796 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4797 
  4798 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4799 modelling and verification task performed in Isabelle/HOL +
  4800 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4801 
  4802 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4803 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4804 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4805 'domain', this makes the theory consistent with mathematical
  4806 literature;
  4807 
  4808 * HOL basics: added overloaded operations "inverse" and "divide"
  4809 (infix "/"), syntax for generic "abs" operation, generic summation
  4810 operator \<Sum>;
  4811 
  4812 * HOL/typedef: simplified package, provide more useful rules (see also
  4813 HOL/subset.thy);
  4814 
  4815 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4816 now expressed as a proper nested rule (old-style tactic scripts may
  4817 require atomize_strip_tac to cope with non-atomic premises);
  4818 
  4819 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4820 to "split_conv" (old name still available for compatibility);
  4821 
  4822 * HOL: improved concrete syntax for strings (e.g. allows translation
  4823 rules with string literals);
  4824 
  4825 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4826  and Fleuriot's mechanization of analysis, including the transcendental
  4827  functions for the reals;
  4828 
  4829 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4830 
  4831 
  4832 *** CTT ***
  4833 
  4834 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4835 "lam" is displayed as TWO lambda-symbols
  4836 
  4837 * CTT: theory Main now available, containing everything (that is, Bool
  4838 and Arith);
  4839 
  4840 
  4841 *** General ***
  4842 
  4843 * Pure: the Simplifier has been implemented properly as a derived rule
  4844 outside of the actual kernel (at last!); the overall performance
  4845 penalty in practical applications is about 50%, while reliability of
  4846 the Isabelle inference kernel has been greatly improved;
  4847 
  4848 * print modes "brackets" and "no_brackets" control output of nested =>
  4849 (types) and ==> (props); the default behaviour is "brackets";
  4850 
  4851 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4852 as assumptions as well;
  4853 
  4854 * system: support Poly/ML 4.0;
  4855 
  4856 * system: isatool install handles KDE version 1 or 2;
  4857 
  4858 
  4859 
  4860 New in Isabelle99-1 (October 2000)
  4861 ----------------------------------
  4862 
  4863 *** Overview of INCOMPATIBILITIES ***
  4864 
  4865 * HOL: simplification of natural numbers is much changed; to partly
  4866 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4867 issue the following ML commands:
  4868 
  4869   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4870   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4871 
  4872 * HOL: simplification no longer dives into case-expressions; this is
  4873 controlled by "t.weak_case_cong" for each datatype t;
  4874 
  4875 * HOL: nat_less_induct renamed to less_induct;
  4876 
  4877 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4878 fixsome to patch .thy and .ML sources automatically;
  4879 
  4880   select_equality  -> some_equality
  4881   select_eq_Ex     -> some_eq_ex
  4882   selectI2EX       -> someI2_ex
  4883   selectI2         -> someI2
  4884   selectI          -> someI
  4885   select1_equality -> some1_equality
  4886   Eps_sym_eq       -> some_sym_eq_trivial
  4887   Eps_eq           -> some_eq_trivial
  4888 
  4889 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4890 
  4891 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4892 instead);
  4893 
  4894 * HOL: the recursion equations generated by 'recdef' are now called
  4895 f.simps instead of f.rules;
  4896 
  4897 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4898 
  4899 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4900 sometimes be needed;
  4901 
  4902 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4903 
  4904 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4905 
  4906 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4907 product is now "<*>" instead of "Times"; the lexicographic product is
  4908 now "<*lex*>" instead of "**";
  4909 
  4910 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4911 of main HOL, but was unused); better use HOL's datatype package;
  4912 
  4913 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4914 the old syntax may be recovered as follows:
  4915 
  4916   syntax (symbols)
  4917     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4918       (infixl "\\<oplus>" 100)
  4919 
  4920 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4921 
  4922 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4923 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4924 internally;
  4925 
  4926 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4927 changed from A/r to A//r;
  4928 
  4929 * ZF: new treatment of arithmetic (nat & int) may break some old
  4930 proofs;
  4931 
  4932 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4933 rulify -> rule_format, elimify -> elim_format, ...);
  4934 
  4935 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4936 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4937 should have to change intro!! to intro? only); replaced "delrule" by
  4938 "rule del";
  4939 
  4940 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4941 
  4942 * Provers: strengthened force_tac by using new first_best_tac;
  4943 
  4944 * LaTeX document preparation: several changes of isabelle.sty (see
  4945 lib/texinputs);
  4946 
  4947 
  4948 *** Document preparation ***
  4949 
  4950 * formal comments (text blocks etc.) in new-style theories may now
  4951 contain antiquotations of thm/prop/term/typ/text to be presented
  4952 according to latex print mode; concrete syntax is like this:
  4953 @{term[show_types] "f(x) = a + x"};
  4954 
  4955 * isatool mkdir provides easy setup of Isabelle session directories,
  4956 including proper document sources;
  4957 
  4958 * generated LaTeX sources are now deleted after successful run
  4959 (isatool document -c); may retain a copy somewhere else via -D option
  4960 of isatool usedir;
  4961 
  4962 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4963 style files, achieving self-contained LaTeX sources and simplifying
  4964 LaTeX debugging;
  4965 
  4966 * old-style theories now produce (crude) LaTeX output as well;
  4967 
  4968 * browser info session directories are now self-contained (may be put
  4969 on WWW server seperately); improved graphs of nested sessions; removed
  4970 graph for 'all sessions';
  4971 
  4972 * several improvements in isabelle style files; \isabellestyle{it}
  4973 produces fake math mode output; \isamarkupheader is now \section by
  4974 default; see lib/texinputs/isabelle.sty etc.;
  4975 
  4976 
  4977 *** Isar ***
  4978 
  4979 * Isar/Pure: local results and corresponding term bindings are now
  4980 subject to Hindley-Milner polymorphism (similar to ML); this
  4981 accommodates incremental type-inference very nicely;
  4982 
  4983 * Isar/Pure: new derived language element 'obtain' supports
  4984 generalized existence reasoning;
  4985 
  4986 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4987 support accumulation of results, without applying any rules yet;
  4988 useful to collect intermediate results without explicit name
  4989 references, and for use with transitivity rules with more than 2
  4990 premises;
  4991 
  4992 * Isar/Pure: scalable support for case-analysis type proofs: new
  4993 'case' language element refers to local contexts symbolically, as
  4994 produced by certain proof methods; internally, case names are attached
  4995 to theorems as "tags";
  4996 
  4997 * Isar/Pure: theory command 'hide' removes declarations from
  4998 class/type/const name spaces;
  4999 
  5000 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5001 indicate potential overloading;
  5002 
  5003 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5004 
  5005 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5006 "{a,b,c}" instead of {a,b,c};
  5007 
  5008 * Isar/Pure now provides its own version of intro/elim/dest
  5009 attributes; useful for building new logics, but beware of confusion
  5010 with the version in Provers/classical;
  5011 
  5012 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5013 case name 'antecedent';
  5014 
  5015 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5016 to the current context is now done automatically);
  5017 
  5018 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5019 for definining proof methods in ML;
  5020 
  5021 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5022 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5023 most cases, one should have to change intro!! to intro? only);
  5024 replaced "delrule" by "rule del";
  5025 
  5026 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5027 'symmetric' attribute (the latter supercedes [RS sym]);
  5028 
  5029 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5030 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5031 well (including splits);
  5032 
  5033 * Isar/Provers: Simplifier and Classical methods now support all kind
  5034 of modifiers used in the past, including 'cong', 'iff', etc.
  5035 
  5036 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5037 of Simplifier and Classical reasoner);
  5038 
  5039 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5040 now support named cases; major packages (inductive, datatype, primrec,
  5041 recdef) support case names and properly name parameters;
  5042 
  5043 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5044 monotonicity conditions are extracted to be proven at end of
  5045 calculations;
  5046 
  5047 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5048 method anyway;
  5049 
  5050 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5051 split_if split_if_asm; datatype package provides theorems foo.splits =
  5052 foo.split foo.split_asm for each datatype;
  5053 
  5054 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5055 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5056 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5057 use "(cases (simplified))" method in proper proof texts);
  5058 
  5059 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5060 
  5061 * Isar: names of theorems etc. may be natural numbers as well;
  5062 
  5063 * Isar: 'pr' command: optional arguments for goals_limit and
  5064 ProofContext.prems_limit; no longer prints theory contexts, but only
  5065 proof states;
  5066 
  5067 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5068 additional print modes to be specified; e.g. "pr(latex)" will print
  5069 proof state according to the Isabelle LaTeX style;
  5070 
  5071 * Isar: improved support for emulating tactic scripts, including proof
  5072 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5073 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5074 (for HOL datatypes);
  5075 
  5076 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5077 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5078 'proof method scripts' have to be in depth-first order;
  5079 
  5080 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5081 
  5082 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5083 should instead use individual commands for printing items
  5084 (print_commands, print_methods etc.);
  5085 
  5086 * Isar: added 'nothing' --- the empty list of theorems;
  5087 
  5088 
  5089 *** HOL ***
  5090 
  5091 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5092 corresponding virtual machine and a specification of its bytecode
  5093 verifier and a lightweight bytecode verifier, including proofs of
  5094 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5095 Cornelia Pusch (see also the homepage of project Bali at
  5096 http://isabelle.in.tum.de/Bali/);
  5097 
  5098 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5099 Clemens Ballarin;
  5100 
  5101 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5102 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5103 Rasmussen;
  5104 
  5105 * HOL/Lattice: fundamental concepts of lattice theory and order
  5106 structures, including duals, properties of bounds versus algebraic
  5107 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5108 Theorem for complete lattices etc.; may also serve as a demonstration
  5109 for abstract algebraic reasoning using axiomatic type classes, and
  5110 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5111 
  5112 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5113 von Oheimb;
  5114 
  5115 * HOL/IMPP: extension of IMP with local variables and mutually
  5116 recursive procedures, by David von Oheimb;
  5117 
  5118 * HOL/Lambda: converted into new-style theory and document;
  5119 
  5120 * HOL/ex/Multiquote: example of multiple nested quotations and
  5121 anti-quotations -- basically a generalized version of de-Bruijn
  5122 representation; very useful in avoiding lifting of operations;
  5123 
  5124 * HOL/record: added general record equality rule to simpset; fixed
  5125 select-update simplification procedure to handle extended records as
  5126 well; admit "r" as field name;
  5127 
  5128 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5129 other numeric types and also as the identity of groups, rings, etc.;
  5130 
  5131 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5132 Types nat and int belong to this axclass;
  5133 
  5134 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5135    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5136    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5137   two terms #m*u and #n*u are replaced by #(m+n)*u
  5138     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5139   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5140     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5141 
  5142 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5143 powerful prover for predicate logic but knows nothing of clasets; see
  5144 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5145 
  5146 * HOL: new version of "case_tac" subsumes both boolean case split and
  5147 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5148 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5149 
  5150 * HOL: simplification no longer dives into case-expressions: only the
  5151 selector expression is simplified, but not the remaining arms; to
  5152 enable full simplification of case-expressions for datatype t, you may
  5153 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5154 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5155 
  5156 * HOL/recdef: the recursion equations generated by 'recdef' for
  5157 function 'f' are now called f.simps instead of f.rules; if all
  5158 termination conditions are proved automatically, these simplification
  5159 rules are added to the simpset, as in primrec; rules may be named
  5160 individually as well, resulting in a separate list of theorems for
  5161 each equation;
  5162 
  5163 * HOL/While is a new theory that provides a while-combinator. It
  5164 permits the definition of tail-recursive functions without the
  5165 provision of a termination measure. The latter is necessary once the
  5166 invariant proof rule for while is applied.
  5167 
  5168 * HOL: new (overloaded) notation for the set of elements below/above
  5169 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5170 
  5171 * HOL: theorems impI, allI, ballI bound as "strip";
  5172 
  5173 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5174 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5175 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5176 
  5177 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5178 
  5179 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5180 main HOL, but was unused);
  5181 
  5182 * HOL: fewer consts declared as global (e.g. have to refer to
  5183 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5184 
  5185 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5186 in case of overlap with user translations (e.g. judgements over
  5187 tuples); (note that the underlying logical represenation is still
  5188 bogus);
  5189 
  5190 
  5191 *** ZF ***
  5192 
  5193 * ZF: simplification automatically cancels common terms in arithmetic
  5194 expressions over nat and int;
  5195 
  5196 * ZF: new treatment of nat to minimize type-checking: all operators
  5197 coerce their operands to a natural number using the function natify,
  5198 making the algebraic laws unconditional;
  5199 
  5200 * ZF: as above, for int: operators coerce their operands to an integer
  5201 using the function intify;
  5202 
  5203 * ZF: the integer library now contains many of the usual laws for the
  5204 orderings, including $<=, and monotonicity laws for $+ and $*;
  5205 
  5206 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5207 simplification;
  5208 
  5209 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5210 to the simplifier and classical reasoner simultaneously;
  5211 
  5212 
  5213 *** General ***
  5214 
  5215 * Provers: blast_tac now handles actual object-logic rules as
  5216 assumptions; note that auto_tac uses blast_tac internally as well;
  5217 
  5218 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5219 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5220 
  5221 * Provers: delrules now handles destruct rules as well (no longer need
  5222 explicit make_elim);
  5223 
  5224 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5225   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5226 use instead the strong form,
  5227   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5228 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5229 from destruct-rules;
  5230 
  5231 * Provers: Simplifier.easy_setup provides a fast path to basic
  5232 Simplifier setup for new object-logics;
  5233 
  5234 * Pure: AST translation rules no longer require constant head on LHS;
  5235 
  5236 * Pure: improved name spaces: ambiguous output is qualified; support
  5237 for hiding of names;
  5238 
  5239 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5240 XSYMBOL_HOME; no longer need to do manual configuration in most
  5241 situations;
  5242 
  5243 * system: compression of ML heaps images may now be controlled via -c
  5244 option of isabelle and isatool usedir (currently only observed by
  5245 Poly/ML);
  5246 
  5247 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5248 useful for remote X11);
  5249 
  5250 * system: provide TAGS file for Isabelle sources;
  5251 
  5252 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5253 order;
  5254 
  5255 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5256 timing flag supersedes proof_timing and Toplevel.trace;
  5257 
  5258 * ML: new combinators |>> and |>>> for incremental transformations
  5259 with secondary results (e.g. certain theory extensions):
  5260 
  5261 * ML: PureThy.add_defs gets additional argument to indicate potential
  5262 overloading (usually false);
  5263 
  5264 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5265 results;
  5266 
  5267 
  5268 
  5269 New in Isabelle99 (October 1999)
  5270 --------------------------------
  5271 
  5272 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5273 
  5274 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5275 are no longer simplified.  (This allows the simplifier to unfold recursive
  5276 functional programs.)  To restore the old behaviour, declare
  5277 
  5278     Delcongs [if_weak_cong];
  5279 
  5280 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5281 complement;
  5282 
  5283 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5284 
  5285 * HOL/datatype: mutual_induct_tac no longer exists --
  5286   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5287 
  5288 * HOL/typedef: fixed type inference for representing set; type
  5289 arguments now have to occur explicitly on the rhs as type constraints;
  5290 
  5291 * ZF: The con_defs part of an inductive definition may no longer refer
  5292 to constants declared in the same theory;
  5293 
  5294 * HOL, ZF: the function mk_cases, generated by the inductive
  5295 definition package, has lost an argument.  To simplify its result, it
  5296 uses the default simpset instead of a supplied list of theorems.
  5297 
  5298 * HOL/List: the constructors of type list are now Nil and Cons;
  5299 
  5300 * Simplifier: the type of the infix ML functions
  5301         setSSolver addSSolver setSolver addSolver
  5302 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5303 for packaging solvers. A solver is created via
  5304         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5305 where the string argument is only a comment.
  5306 
  5307 
  5308 *** Proof tools ***
  5309 
  5310 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5311 decision procedure for linear arithmetic. Currently it is used for
  5312 types `nat', `int', and `real' in HOL (see below); it can, should and
  5313 will be instantiated for other types and logics as well.
  5314 
  5315 * The simplifier now accepts rewrite rules with flexible heads, eg
  5316      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5317   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5318   matching.
  5319 
  5320 
  5321 *** General ***
  5322 
  5323 * New Isabelle/Isar subsystem provides an alternative to traditional
  5324 tactical theorem proving; together with the ProofGeneral/isar user
  5325 interface it offers an interactive environment for developing human
  5326 readable proof documents (Isar == Intelligible semi-automated
  5327 reasoning); for further information see isatool doc isar-ref,
  5328 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5329 
  5330 * improved and simplified presentation of theories: better HTML markup
  5331 (including colors), graph views in several sizes; isatool usedir now
  5332 provides a proper interface for user theories (via -P option); actual
  5333 document preparation based on (PDF)LaTeX is available as well (for
  5334 new-style theories only); see isatool doc system for more information;
  5335 
  5336 * native support for Proof General, both for classic Isabelle and
  5337 Isabelle/Isar;
  5338 
  5339 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5340 using the graph browser tool;
  5341 
  5342 * Isabelle manuals now also available as PDF;
  5343 
  5344 * theory loader rewritten from scratch (may not be fully
  5345 bug-compatible); old loadpath variable has been replaced by show_path,
  5346 add_path, del_path, reset_path functions; new operations such as
  5347 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5348 isatool doc ref);
  5349 
  5350 * improved isatool install: option -k creates KDE application icon,
  5351 option -p DIR installs standalone binaries;
  5352 
  5353 * added ML_PLATFORM setting (useful for cross-platform installations);
  5354 more robust handling of platform specific ML images for SML/NJ;
  5355 
  5356 * the settings environment is now statically scoped, i.e. it is never
  5357 created again in sub-processes invoked from isabelle, isatool, or
  5358 Isabelle;
  5359 
  5360 * path element specification '~~' refers to '$ISABELLE_HOME';
  5361 
  5362 * in locales, the "assumes" and "defines" parts may be omitted if
  5363 empty;
  5364 
  5365 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5366 long arrows);
  5367 
  5368 * new print_mode "HTML";
  5369 
  5370 * new flag show_tags controls display of tags of theorems (which are
  5371 basically just comments that may be attached by some tools);
  5372 
  5373 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5374 mode and goal output format:
  5375 
  5376 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5377 244c244
  5378 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5379 ---
  5380 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5381 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5382 181c181
  5383 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5384 ---
  5385 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5386 
  5387 * function bind_thms stores lists of theorems (cf. bind_thm);
  5388 
  5389 * new shorthand tactics ftac, eatac, datac, fatac;
  5390 
  5391 * qed (and friends) now accept "" as result name; in that case the
  5392 theorem is not stored, but proper checks and presentation of the
  5393 result still apply;
  5394 
  5395 * theorem database now also indexes constants "Trueprop", "all",
  5396 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5397 
  5398 
  5399 *** HOL ***
  5400 
  5401 ** HOL arithmetic **
  5402 
  5403 * There are now decision procedures for linear arithmetic over nat and
  5404 int:
  5405 
  5406 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5407 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5408 are treated as atomic; subformulae not involving type `nat' or `int'
  5409 are ignored; quantified subformulae are ignored unless they are
  5410 positive universal or negative existential. The tactic has to be
  5411 invoked by hand and can be a little bit slow. In particular, the
  5412 running time is exponential in the number of occurrences of `min' and
  5413 `max', and `-' on `nat'.
  5414 
  5415 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5416 (negated) (in)equalities among the premises and the conclusion into
  5417 account (i.e. no compound formulae) and does not know about `min' and
  5418 `max', and `-' on `nat'. It is fast and is used automatically by the
  5419 simplifier.
  5420 
  5421 NB: At the moment, these decision procedures do not cope with mixed
  5422 nat/int formulae where the two parts interact, such as `m < n ==>
  5423 int(m) < int(n)'.
  5424 
  5425 * HOL/Numeral provides a generic theory of numerals (encoded
  5426 efficiently as bit strings); setup for types nat/int/real is in place;
  5427 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5428 int, existing theories and proof scripts may require a few additional
  5429 type constraints;
  5430 
  5431 * integer division and remainder can now be performed on constant
  5432 arguments;
  5433 
  5434 * many properties of integer multiplication, division and remainder
  5435 are now available;
  5436 
  5437 * An interface to the Stanford Validity Checker (SVC) is available through the
  5438 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5439 are proved automatically.  SVC must be installed separately, and its results
  5440 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5441 invocation of the underlying oracle).  For SVC see
  5442   http://verify.stanford.edu/SVC
  5443 
  5444 * IsaMakefile: the HOL-Real target now builds an actual image;
  5445 
  5446 
  5447 ** HOL misc **
  5448 
  5449 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5450 (in Isabelle/Isar) -- by Gertrud Bauer;
  5451 
  5452 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5453 analysis for assembly languages with subtypes;
  5454 
  5455 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5456 -- avoids syntactic ambiguities and treats state, transition, and
  5457 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5458 changed syntax and (many) tactics;
  5459 
  5460 * HOL/inductive: Now also handles more general introduction rules such
  5461   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5462   theorems are now maintained within the theory (maintained via the
  5463   "mono" attribute);
  5464 
  5465 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5466   (using function types) such as
  5467 
  5468   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5469 
  5470 * HOL/record: record_simproc (part of the default simpset) takes care
  5471 of selectors applied to updated records; record_split_tac is no longer
  5472 part of the default claset; update_defs may now be removed from the
  5473 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5474 
  5475   claset_ref () := claset() addSWrapper record_split_wrapper;
  5476   Delsimprocs [record_simproc]
  5477 
  5478 * HOL/typedef: fixed type inference for representing set; type
  5479 arguments now have to occur explicitly on the rhs as type constraints;
  5480 
  5481 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5482 names rather than an ML expression;
  5483 
  5484 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5485 supplied later.  Program schemes can be defined, such as
  5486     "While B C s = (if B s then While B C (C s) else s)"
  5487 where the well-founded relation can be chosen after B and C have been given.
  5488 
  5489 * HOL/List: the constructors of type list are now Nil and Cons;
  5490 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5491 course, ML tools referring to List.list.op # etc. have to be adapted;
  5492 
  5493 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5494 disabled by default; run isabelle with option -m HOL to get back to
  5495 the original Gordon/HOL-style output;
  5496 
  5497 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5498 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5499 
  5500 * HOL basic syntax simplified (more orthogonal): all variants of
  5501 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5502 Eps operator is provided as well: "SOME x. P[x]";
  5503 
  5504 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5505 
  5506 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5507 thus available for user theories;
  5508 
  5509 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5510 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5511 time;
  5512 
  5513 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5514 several times and then mp;
  5515 
  5516 
  5517 *** LK ***
  5518 
  5519 * the notation <<...>> is now available as a notation for sequences of
  5520 formulas;
  5521 
  5522 * the simplifier is now installed
  5523 
  5524 * the axiom system has been generalized (thanks to Soren Heilmann)
  5525 
  5526 * the classical reasoner now has a default rule database
  5527 
  5528 
  5529 *** ZF ***
  5530 
  5531 * new primrec section allows primitive recursive functions to be given
  5532 directly (as in HOL) over datatypes and the natural numbers;
  5533 
  5534 * new tactics induct_tac and exhaust_tac for induction (or case
  5535 analysis) over datatypes and the natural numbers;
  5536 
  5537 * the datatype declaration of type T now defines the recursor T_rec;
  5538 
  5539 * simplification automatically does freeness reasoning for datatype
  5540 constructors;
  5541 
  5542 * automatic type-inference, with AddTCs command to insert new
  5543 type-checking rules;
  5544 
  5545 * datatype introduction rules are now added as Safe Introduction rules
  5546 to the claset;
  5547 
  5548 * the syntax "if P then x else y" is now available in addition to
  5549 if(P,x,y);
  5550 
  5551 
  5552 *** Internal programming interfaces ***
  5553 
  5554 * tuned simplifier trace output; new flag debug_simp;
  5555 
  5556 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5557 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5558 
  5559 * AxClass.axclass_tac lost the theory argument;
  5560 
  5561 * tuned current_goals_markers semantics: begin / end goal avoids
  5562 printing empty lines;
  5563 
  5564 * removed prs and prs_fn hook, which was broken because it did not
  5565 include \n in its semantics, forcing writeln to add one
  5566 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5567 string -> unit if you really want to output text without newline;
  5568 
  5569 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5570 plain output, interface builders may have to enable 'isabelle_font'
  5571 mode to get Isabelle font glyphs as before;
  5572 
  5573 * refined token_translation interface; INCOMPATIBILITY: output length
  5574 now of type real instead of int;
  5575 
  5576 * theory loader actions may be traced via new ThyInfo.add_hook
  5577 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5578 your own database of information attached to *whole* theories -- as
  5579 opposed to intra-theory data slots offered via TheoryDataFun;
  5580 
  5581 * proper handling of dangling sort hypotheses (at last!);
  5582 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5583 extra sort hypotheses that can be witnessed from the type signature;
  5584 the force_strip_shyps flag is gone, any remaining shyps are simply
  5585 left in the theorem (with a warning issued by strip_shyps_warning);
  5586 
  5587 
  5588 
  5589 New in Isabelle98-1 (October 1998)
  5590 ----------------------------------
  5591 
  5592 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5593 
  5594 * several changes of automated proof tools;
  5595 
  5596 * HOL: major changes to the inductive and datatype packages, including
  5597 some minor incompatibilities of theory syntax;
  5598 
  5599 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5600 called `inj_on';
  5601 
  5602 * HOL: removed duplicate thms in Arith:
  5603   less_imp_add_less  should be replaced by  trans_less_add1
  5604   le_imp_add_le      should be replaced by  trans_le_add1
  5605 
  5606 * HOL: unary minus is now overloaded (new type constraints may be
  5607 required);
  5608 
  5609 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5610 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5611 now taken as an integer constant.
  5612 
  5613 * Pure: ML function 'theory_of' renamed to 'theory';
  5614 
  5615 
  5616 *** Proof tools ***
  5617 
  5618 * Simplifier:
  5619   1. Asm_full_simp_tac is now more aggressive.
  5620      1. It will sometimes reorient premises if that increases their power to
  5621         simplify.
  5622      2. It does no longer proceed strictly from left to right but may also
  5623         rotate premises to achieve further simplification.
  5624      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5625      old Asm_full_simp_tac in that it does not rotate premises.
  5626   2. The simplifier now knows a little bit about nat-arithmetic.
  5627 
  5628 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5629 allows for selected deletion of wrappers, by introduction of names for
  5630 wrapper functionals.  This implies that addbefore, addSbefore,
  5631 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5632 and that adding two tactics with the same name overwrites the first
  5633 one (emitting a warning).
  5634   type wrapper = (int -> tactic) -> (int -> tactic)
  5635   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5636   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5637   delWrapper, delSWrapper: claset *  string            -> claset
  5638   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5639 
  5640 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5641 semantics; addbefore now affects only the unsafe part of step_tac
  5642 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5643 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5644 by Force_tac;
  5645 
  5646 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5647 compWrapper; added safe wrapper (and access functions for it);
  5648 
  5649 * HOL/split_all_tac is now much faster and fails if there is nothing
  5650 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5651 and the names of the automatically generated variables have changed.
  5652 split_all_tac has moved within claset() from unsafe wrappers to safe
  5653 wrappers, which means that !!-bound variables are split much more
  5654 aggressively, and safe_tac and clarify_tac now split such variables.
  5655 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5656 Note: the same holds for record_split_tac, which does the job of
  5657 split_all_tac for record fields.
  5658 
  5659 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5660 permanently to the default simpset using Addsplits just like
  5661 Addsimps. They can be removed via Delsplits just like
  5662 Delsimps. Lower-case versions are also available.
  5663 
  5664 * HOL/Simplifier: The rule split_if is now part of the default
  5665 simpset. This means that the simplifier will eliminate all occurrences
  5666 of if-then-else in the conclusion of a goal. To prevent this, you can
  5667 either remove split_if completely from the default simpset by
  5668 `Delsplits [split_if]' or remove it in a specific call of the
  5669 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5670 other case splitting rules to/from the default simpset: every datatype
  5671 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5672 t is the name of the datatype).
  5673 
  5674 * Classical reasoner / Simplifier combination: new force_tac (and
  5675 derivatives Force_tac, force) combines rewriting and classical
  5676 reasoning (and whatever other tools) similarly to auto_tac, but is
  5677 aimed to solve the given subgoal completely.
  5678 
  5679 
  5680 *** General ***
  5681 
  5682 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5683 and `goalw': the theory is no longer needed as an explicit argument -
  5684 the current theory context is used; assumptions are no longer returned
  5685 at the ML-level unless one of them starts with ==> or !!; it is
  5686 recommended to convert to these new commands using isatool fixgoal
  5687 (backup your sources first!);
  5688 
  5689 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5690 the current theory context, and 'theory' to lookup stored theories;
  5691 
  5692 * new theory section 'locale' for declaring constants, assumptions and
  5693 definitions that have local scope;
  5694 
  5695 * new theory section 'nonterminals' for purely syntactic types;
  5696 
  5697 * new theory section 'setup' for generic ML setup functions
  5698 (e.g. package initialization);
  5699 
  5700 * the distribution now includes Isabelle icons: see
  5701 lib/logo/isabelle-{small,tiny}.xpm;
  5702 
  5703 * isatool install - install binaries with absolute references to
  5704 ISABELLE_HOME/bin;
  5705 
  5706 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5707 
  5708 * print mode 'emacs' reserved for Isamode;
  5709 
  5710 * support multiple print (ast) translations per constant name;
  5711 
  5712 * theorems involving oracles are now printed with a suffixed [!];
  5713 
  5714 
  5715 *** HOL ***
  5716 
  5717 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5718 
  5719 * HOL/inductive package reorganized and improved: now supports mutual
  5720 definitions such as
  5721 
  5722   inductive EVEN ODD
  5723     intrs
  5724       null "0 : EVEN"
  5725       oddI "n : EVEN ==> Suc n : ODD"
  5726       evenI "n : ODD ==> Suc n : EVEN"
  5727 
  5728 new theorem list "elims" contains an elimination rule for each of the
  5729 recursive sets; inductive definitions now handle disjunctive premises
  5730 correctly (also ZF);
  5731 
  5732 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5733 "mutual_induct" no longer exists - the induction rule is always
  5734 contained in "induct";
  5735 
  5736 
  5737 * HOL/datatype package re-implemented and greatly improved: now
  5738 supports mutually recursive datatypes such as
  5739 
  5740   datatype
  5741     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5742             | SUM ('a aexp) ('a aexp)
  5743             | DIFF ('a aexp) ('a aexp)
  5744             | NUM 'a
  5745   and
  5746     'a bexp = LESS ('a aexp) ('a aexp)
  5747             | AND ('a bexp) ('a bexp)
  5748             | OR ('a bexp) ('a bexp)
  5749 
  5750 as well as indirectly recursive datatypes such as
  5751 
  5752   datatype
  5753     ('a, 'b) term = Var 'a
  5754                   | App 'b ((('a, 'b) term) list)
  5755 
  5756 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5757 induction on mutually / indirectly recursive datatypes.
  5758 
  5759 Primrec equations are now stored in theory and can be accessed via
  5760 <function_name>.simps.
  5761 
  5762 INCOMPATIBILITIES:
  5763 
  5764   - Theories using datatypes must now have theory Datatype as an
  5765     ancestor.
  5766   - The specific <typename>.induct_tac no longer exists - use the
  5767     generic induct_tac instead.
  5768   - natE has been renamed to nat.exhaust - use exhaust_tac
  5769     instead of res_inst_tac ... natE. Note that the variable
  5770     names in nat.exhaust differ from the names in natE, this
  5771     may cause some "fragile" proofs to fail.
  5772   - The theorems split_<typename>_case and split_<typename>_case_asm
  5773     have been renamed to <typename>.split and <typename>.split_asm.
  5774   - Since default sorts of type variables are now handled correctly,
  5775     some datatype definitions may have to be annotated with explicit
  5776     sort constraints.
  5777   - Primrec definitions no longer require function name and type
  5778     of recursive argument.
  5779 
  5780 Consider using isatool fixdatatype to adapt your theories and proof
  5781 scripts to the new package (backup your sources first!).
  5782 
  5783 
  5784 * HOL/record package: considerably improved implementation; now
  5785 includes concrete syntax for record types, terms, updates; theorems
  5786 for surjective pairing and splitting !!-bound record variables; proof
  5787 support is as follows:
  5788 
  5789   1) standard conversions (selectors or updates applied to record
  5790 constructor terms) are part of the standard simpset;
  5791 
  5792   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5793 made part of standard simpset and claset via addIffs;
  5794 
  5795   3) a tactic for record field splitting (record_split_tac) is part of
  5796 the standard claset (addSWrapper);
  5797 
  5798 To get a better idea about these rules you may retrieve them via
  5799 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5800 the name of your record type.
  5801 
  5802 The split tactic 3) conceptually simplifies by the following rule:
  5803 
  5804   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5805 
  5806 Thus any record variable that is bound by meta-all will automatically
  5807 blow up into some record constructor term, consequently the
  5808 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5809 solve record problems automatically.
  5810 
  5811 
  5812 * reorganized the main HOL image: HOL/Integ and String loaded by
  5813 default; theory Main includes everything;
  5814 
  5815 * automatic simplification of integer sums and comparisons, using cancellation;
  5816 
  5817 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5818 
  5819 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5820 
  5821 * many new identities for unions, intersections, set difference, etc.;
  5822 
  5823 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5824 called split_if, split_split, split_sum_case and split_nat_case (to go
  5825 with add/delsplits);
  5826 
  5827 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5828 (?x::unit) = (); this is made part of the default simpset, which COULD
  5829 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5830 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5831 unit_abs_eta_conv is added in order to counter the effect of
  5832 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5833 %u.f();
  5834 
  5835 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5836 makes more sense);
  5837 
  5838 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5839   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5840   disjointness reasoning but breaking a few old proofs.
  5841 
  5842 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5843 to 'converse' from 'inverse' (for compatibility with ZF and some
  5844 literature);
  5845 
  5846 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5847 the well-founded relation;
  5848 
  5849 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5850     Compl A.  The "Compl" syntax remains available as input syntax for this
  5851     release ONLY.
  5852 
  5853 * HOL/Update: new theory of function updates:
  5854     f(a:=b) == %x. if x=a then b else f x
  5855 may also be iterated as in f(a:=b,c:=d,...);
  5856 
  5857 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5858 
  5859 * HOL/List:
  5860   - new function list_update written xs[i:=v] that updates the i-th
  5861     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5862   - new function `upt' written [i..j(] which generates the list
  5863     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5864     bound write [i..j], which is a shorthand for [i..j+1(].
  5865   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5866 
  5867 * HOL/Arith:
  5868   - removed 'pred' (predecessor) function;
  5869   - generalized some theorems about n-1;
  5870   - many new laws about "div" and "mod";
  5871   - new laws about greatest common divisors (see theory ex/Primes);
  5872 
  5873 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5874 instead of "inverse";
  5875 
  5876 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5877   of the multiset ordering;
  5878 
  5879 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5880   (not included by default);
  5881 
  5882 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5883 
  5884 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5885   programs, i.e. different program variables may have different types.
  5886 
  5887 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5888   [previously, this check worked only if the rewrite rule was unconditional]
  5889   Now rew can involve either definitions or equalities (either == or =).
  5890 
  5891 
  5892 *** ZF ***
  5893 
  5894 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5895   only the theorems proved on ZF.ML;
  5896 
  5897 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5898   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5899   disjointness reasoning but breaking a few old proofs.
  5900 
  5901 * ZF/Update: new theory of function updates
  5902     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5903   may also be iterated as in f(a:=b,c:=d,...);
  5904 
  5905 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5906 
  5907 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5908   [previously, this check worked only if the rewrite rule was unconditional]
  5909   Now rew can involve either definitions or equalities (either == or =).
  5910 
  5911 * case_tac provided for compatibility with HOL
  5912     (like the old excluded_middle_tac, but with subgoals swapped)
  5913 
  5914 
  5915 *** Internal programming interfaces ***
  5916 
  5917 * Pure: several new basic modules made available for general use, see
  5918 also src/Pure/README;
  5919 
  5920 * improved the theory data mechanism to support encapsulation (data
  5921 kind name replaced by private Object.kind, acting as authorization
  5922 key); new type-safe user interface via functor TheoryDataFun; generic
  5923 print_data function becomes basically useless;
  5924 
  5925 * removed global_names compatibility flag -- all theory declarations
  5926 are qualified by default;
  5927 
  5928 * module Pure/Syntax now offers quote / antiquote translation
  5929 functions (useful for Hoare logic etc. with implicit dependencies);
  5930 see HOL/ex/Antiquote for an example use;
  5931 
  5932 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5933 cterm -> thm;
  5934 
  5935 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5936 subgoal;
  5937 
  5938 * Display.print_goals function moved to Locale.print_goals;
  5939 
  5940 * standard print function for goals supports current_goals_markers
  5941 variable for marking begin of proof, end of proof, start of goal; the
  5942 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5943 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5944 for example;
  5945 
  5946 
  5947 
  5948 New in Isabelle98 (January 1998)
  5949 --------------------------------
  5950 
  5951 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5952 
  5953 * changed lexical syntax of terms / types: dots made part of long
  5954 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5955 
  5956 * simpset (and claset) reference variable replaced by functions
  5957 simpset / simpset_ref;
  5958 
  5959 * no longer supports theory aliases (via merge) and non-trivial
  5960 implicit merge of thms' signatures;
  5961 
  5962 * most internal names of constants changed due to qualified names;
  5963 
  5964 * changed Pure/Sequence interface (see Pure/seq.ML);
  5965 
  5966 
  5967 *** General Changes ***
  5968 
  5969 * hierachically structured name spaces (for consts, types, axms, thms
  5970 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5971 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5972 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5973 long_names for fully qualified output names; NOTE: ML programs
  5974 (special tactics, packages etc.) referring to internal names may have
  5975 to be adapted to cope with fully qualified names; in case of severe
  5976 backward campatibility problems try setting 'global_names' at compile
  5977 time to have enrything declared within a flat name space; one may also
  5978 fine tune name declarations in theories via the 'global' and 'local'
  5979 section;
  5980 
  5981 * reimplemented the implicit simpset and claset using the new anytype
  5982 data filed in signatures; references simpset:simpset ref etc. are
  5983 replaced by functions simpset:unit->simpset and
  5984 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5985 to patch your ML files accordingly;
  5986 
  5987 * HTML output now includes theory graph data for display with Java
  5988 applet or isatool browser; data generated automatically via isatool
  5989 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5990 
  5991 * defs may now be conditional; improved rewrite_goals_tac to handle
  5992 conditional equations;
  5993 
  5994 * defs now admits additional type arguments, using TYPE('a) syntax;
  5995 
  5996 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5997 creates a new theory node; implicit merge of thms' signatures is
  5998 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5999 transfer:theory->thm->thm in (rare) cases;
  6000 
  6001 * improved handling of draft signatures / theories; draft thms (and
  6002 ctyps, cterms) are automatically promoted to real ones;
  6003 
  6004 * slightly changed interfaces for oracles: admit many per theory, named
  6005 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6006 
  6007 * print_goals: optional output of const types (set show_consts and
  6008 show_types);
  6009 
  6010 * improved output of warnings (###) and errors (***);
  6011 
  6012 * subgoal_tac displays a warning if the new subgoal has type variables;
  6013 
  6014 * removed old README and Makefiles;
  6015 
  6016 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6017 
  6018 * removed obsolete init_pps and init_database;
  6019 
  6020 * deleted the obsolete tactical STATE, which was declared by
  6021     fun STATE tacfun st = tacfun st st;
  6022 
  6023 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6024 (which abbreviates $HOME);
  6025 
  6026 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6027 use isatool fixseq to adapt your ML programs (this works for fully
  6028 qualified references to the Sequence structure only!);
  6029 
  6030 * use_thy no longer requires writable current directory; it always
  6031 reloads .ML *and* .thy file, if either one is out of date;
  6032 
  6033 
  6034 *** Classical Reasoner ***
  6035 
  6036 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6037 tactics that use classical reasoning to simplify a subgoal without
  6038 splitting it into several subgoals;
  6039 
  6040 * Safe_tac: like safe_tac but uses the default claset;
  6041 
  6042 
  6043 *** Simplifier ***
  6044 
  6045 * added simplification meta rules:
  6046     (asm_)(full_)simplify: simpset -> thm -> thm;
  6047 
  6048 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6049 logics (again);
  6050 
  6051 * added prems argument to simplification procedures;
  6052 
  6053 * HOL, FOL, ZF: added infix function `addsplits':
  6054   instead of `<simpset> setloop (split_tac <thms>)'
  6055   you can simply write `<simpset> addsplits <thms>'
  6056 
  6057 
  6058 *** Syntax ***
  6059 
  6060 * TYPE('a) syntax for type reflection terms;
  6061 
  6062 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6063 
  6064 * pretty printer: changed order of mixfix annotation preference (again!);
  6065 
  6066 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6067 
  6068 
  6069 *** HOL ***
  6070 
  6071 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6072   with `addloop' of the simplifier to faciliate case splitting in premises.
  6073 
  6074 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6075 
  6076 * HOL/Auth: new protocol proofs including some for the Internet
  6077   protocol TLS;
  6078 
  6079 * HOL/Map: new theory of `maps' a la VDM;
  6080 
  6081 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6082 cancelling out common nat summands from =, <, <= (in)equalities, or
  6083 differences; simplification procedures nat_cancel_factor for
  6084 cancelling common factor from =, <, <= (in)equalities over natural
  6085 sums; nat_cancel contains both kinds of procedures, it is installed by
  6086 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6087 
  6088 * HOL/simplifier: terms of the form
  6089   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6090   are rewritten to
  6091   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6092   and those of the form
  6093   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6094   are rewritten to
  6095   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6096 
  6097 * HOL/datatype
  6098   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6099 
  6100   P(t_case f1 ... fn x) =
  6101      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6102         ...
  6103        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6104      )
  6105 
  6106   and a theorem `split_t_case_asm' of the form
  6107 
  6108   P(t_case f1 ... fn x) =
  6109     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6110         ...
  6111        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6112      )
  6113   which can be added to a simpset via `addsplits'. The existing theorems
  6114   expand_list_case and expand_option_case have been renamed to
  6115   split_list_case and split_option_case.
  6116 
  6117 * HOL/Arithmetic:
  6118   - `pred n' is automatically converted to `n-1'.
  6119     Users are strongly encouraged not to use `pred' any longer,
  6120     because it will disappear altogether at some point.
  6121   - Users are strongly encouraged to write "0 < n" rather than
  6122     "n ~= 0". Theorems and proof tools have been modified towards this
  6123     `standard'.
  6124 
  6125 * HOL/Lists:
  6126   the function "set_of_list" has been renamed "set" (and its theorems too);
  6127   the function "nth" now takes its arguments in the reverse order and
  6128   has acquired the infix notation "!" as in "xs!n".
  6129 
  6130 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6131 
  6132 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6133   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6134 
  6135 * HOL/record: extensible records with schematic structural subtyping
  6136 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6137 still lacks various theorems and concrete record syntax;
  6138 
  6139 
  6140 *** HOLCF ***
  6141 
  6142 * removed "axioms" and "generated by" sections;
  6143 
  6144 * replaced "ops" section by extended "consts" section, which is capable of
  6145   handling the continuous function space "->" directly;
  6146 
  6147 * domain package:
  6148   . proves theorems immediately and stores them in the theory,
  6149   . creates hierachical name space,
  6150   . now uses normal mixfix annotations (instead of cinfix...),
  6151   . minor changes to some names and values (for consistency),
  6152   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6153   . separator between mutual domain defs: changed "," to "and",
  6154   . improved handling of sort constraints;  now they have to
  6155     appear on the left-hand side of the equations only;
  6156 
  6157 * fixed LAM <x,y,zs>.b syntax;
  6158 
  6159 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6160 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6161 
  6162 
  6163 *** FOL and ZF ***
  6164 
  6165 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6166   with `addloop' of the simplifier to faciliate case splitting in premises.
  6167 
  6168 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6169 in HOL, they strip ALL and --> from proved theorems;
  6170 
  6171 
  6172 
  6173 New in Isabelle94-8 (May 1997)
  6174 ------------------------------
  6175 
  6176 *** General Changes ***
  6177 
  6178 * new utilities to build / run / maintain Isabelle etc. (in parts
  6179 still somewhat experimental); old Makefiles etc. still functional;
  6180 
  6181 * new 'Isabelle System Manual';
  6182 
  6183 * INSTALL text, together with ./configure and ./build scripts;
  6184 
  6185 * reimplemented type inference for greater efficiency, better error
  6186 messages and clean internal interface;
  6187 
  6188 * prlim command for dealing with lots of subgoals (an easier way of
  6189 setting goals_limit);
  6190 
  6191 
  6192 *** Syntax ***
  6193 
  6194 * supports alternative (named) syntax tables (parser and pretty
  6195 printer); internal interface is provided by add_modesyntax(_i);
  6196 
  6197 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6198 be used in conjunction with the Isabelle symbol font; uses the
  6199 "symbols" syntax table;
  6200 
  6201 * added token_translation interface (may translate name tokens in
  6202 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6203 the current print_mode); IMPORTANT: user print translation functions
  6204 are responsible for marking newly introduced bounds
  6205 (Syntax.mark_boundT);
  6206 
  6207 * token translations for modes "xterm" and "xterm_color" that display
  6208 names in bold, underline etc. or colors (which requires a color
  6209 version of xterm);
  6210 
  6211 * infixes may now be declared with names independent of their syntax;
  6212 
  6213 * added typed_print_translation (like print_translation, but may
  6214 access type of constant);
  6215 
  6216 
  6217 *** Classical Reasoner ***
  6218 
  6219 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6220 some limitations.  Blast_tac...
  6221   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6222   + ignores elimination rules that don't have the correct format
  6223         (the conclusion MUST be a formula variable)
  6224   + ignores types, which can make HOL proofs fail
  6225   + rules must not require higher-order unification, e.g. apply_type in ZF
  6226     [message "Function Var's argument not a bound variable" relates to this]
  6227   + its proof strategy is more general but can actually be slower
  6228 
  6229 * substitution with equality assumptions no longer permutes other
  6230 assumptions;
  6231 
  6232 * minor changes in semantics of addafter (now called addaltern); renamed
  6233 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6234 (and access functions for it);
  6235 
  6236 * improved combination of classical reasoner and simplifier:
  6237   + functions for handling clasimpsets
  6238   + improvement of addss: now the simplifier is called _after_ the
  6239     safe steps.
  6240   + safe variant of addss called addSss: uses safe simplifications
  6241     _during_ the safe steps. It is more complete as it allows multiple
  6242     instantiations of unknowns (e.g. with slow_tac).
  6243 
  6244 *** Simplifier ***
  6245 
  6246 * added interface for simplification procedures (functions that
  6247 produce *proven* rewrite rules on the fly, depending on current
  6248 redex);
  6249 
  6250 * ordering on terms as parameter (used for ordered rewriting);
  6251 
  6252 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6253 
  6254 * the solver is now split into a safe and an unsafe part.
  6255 This should be invisible for the normal user, except