NEWS
author boehmes
Fri Aug 21 13:38:57 2009 +0200 (2009-08-21)
changeset 32388 b23a4326b9bb
parent 32365 9b74d0339c44
child 32427 0a94e1f264ce
permissions -rw-r--r--
added Mirabelle to NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * New testing tool "Mirabelle" for automated (proof) tools. Applies several
    22 tools and tactics like sledgehammer, metis, or quickcheck, to every proof step
    23 in a theory. To be used in batch mode via "isabelle mirabelle".
    24 
    25 * New proof method "sos" (sum of squares) for nonlinear real arithmetic
    26 (originally due to John Harison). It requires Library/Sum_Of_Squares.
    27 It is not a complete decision procedure but works well in practice
    28 on quantifier-free real arithmetic with +, -, *, ^, =, <= and <,
    29 i.e. boolean combinations of equalities and inequalities between
    30 polynomials. It makes use of external semidefinite programming solvers.
    31 For more information and examples see Library/Sum_Of_Squares.
    32 
    33 * Set.UNIV and Set.empty are mere abbreviations for top and bot.  INCOMPATIBILITY.
    34 
    35 * More convenient names for set intersection and union.  INCOMPATIBILITY:
    36 
    37     Set.Int ~>  Set.inter
    38     Set.Un ~>   Set.union
    39 
    40 * Code generator attributes follow the usual underscore convention:
    41     code_unfold     replaces    code unfold
    42     code_post       replaces    code post
    43     etc.
    44   INCOMPATIBILITY.
    45 
    46 * New quickcheck implementation using new code generator.
    47 
    48 * New class "boolean_algebra".
    49 
    50 * Refinements to lattices classes:
    51   - added boolean_algebra type class
    52   - less default intro/elim rules in locale variant, more default
    53     intro/elim rules in class variant: more uniformity
    54   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    55   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    56   - renamed ACI to inf_sup_aci
    57   - class "complete_lattice" moved to separate theory "complete_lattice";
    58     corresponding constants renamed:
    59     
    60     Set.Inf ~>      Complete_Lattice.Inf
    61     Set.Sup ~>      Complete_Lattice.Sup
    62     Set.INFI ~>     Complete_Lattice.INFI
    63     Set.SUPR ~>     Complete_Lattice.SUPR
    64     Set.Inter ~>    Complete_Lattice.Inter
    65     Set.Union ~>    Complete_Lattice.Union
    66     Set.INTER ~>    Complete_Lattice.INTER
    67     Set.UNION ~>    Complete_Lattice.UNION
    68 
    69   INCOMPATIBILITY.
    70 
    71 * Class semiring_div requires superclass no_zero_divisors and proof of
    72 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    73 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    74 generalized to class semiring_div, subsuming former theorems
    75 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    76 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    77 INCOMPATIBILITY.
    78 
    79 * Power operations on relations and functions are now one dedicate
    80 constant compow with infix syntax "^^".  Power operations on
    81 multiplicative monoids retains syntax "^" and is now defined generic
    82 in class power.  INCOMPATIBILITY.
    83 
    84 * Relation composition "R O S" now has a "more standard" argument order,
    85 i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
    86 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
    87 may occationally break, since the O_assoc rule was not rewritten like this.
    88 Fix using O_assoc[symmetric].
    89 The same applies to the curried version "R OO S".
    90 
    91 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    92 infinite sets. It is shown that they form a complete lattice.
    93 
    94 * ML antiquotation @{code_datatype} inserts definition of a datatype
    95 generated by the code generator; see Predicate.thy for an example.
    96 
    97 * New method "linarith" invokes existing linear arithmetic decision
    98 procedure only.
    99 
   100 * Implementation of quickcheck using generic code generator; default
   101 generators are provided for all suitable HOL types, records and
   102 datatypes.
   103 
   104 * Constants Set.Pow and Set.image now with authentic syntax;
   105 object-logic definitions Set.Pow_def and Set.image_def.
   106 INCOMPATIBILITY.
   107 
   108 * Renamed theorems:
   109 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   110 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   111 Suc_plus1 -> Suc_eq_plus1
   112 
   113 * New sledgehammer option "Full Types" in Proof General settings menu.
   114 Causes full type information to be output to the ATPs.  This slows
   115 ATPs down considerably but eliminates a source of unsound "proofs"
   116 that fail later.
   117 
   118 * Discontinued ancient tradition to suffix certain ML module names
   119 with "_package", e.g.:
   120 
   121     DatatypePackage ~> Datatype
   122     InductivePackage ~> Inductive
   123 
   124     etc.
   125 
   126 INCOMPATIBILITY.
   127 
   128 * NewNumberTheory: Jeremy Avigad's new version of part of
   129 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
   130 
   131 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
   132 
   133 * Abbreviation "arbitrary" of "undefined" has disappeared; use
   134 "undefined" directly.  INCOMPATIBILITY.
   135 
   136 * New evaluator "approximate" approximates an real valued term using
   137 the same method as the approximation method.
   138 
   139 * Method "approximate" supports now arithmetic expressions as
   140 boundaries of intervals and implements interval splitting and Taylor
   141 series expansion.
   142 
   143 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   144 the theorems in DERIV_intros assumes composition with an additional
   145 function and matches a variable to the derivative, which has to be
   146 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   147 the derivative of most elementary terms.
   148 
   149 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   150 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   151 
   152 
   153 *** ML ***
   154 
   155 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   156 parallel tactical reasoning.
   157 
   158 * Tactical FOCUS is similar to SUBPROOF, but allows the body tactic to
   159 introduce new subgoals and schematic variables.  FOCUS_PARAMS is
   160 similar, but focuses on the parameter prefix only, leaving subgoal
   161 premises unchanged.
   162 
   163 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   164 functors have their own ML name space there is no point to mark them
   165 separately.)  Minor INCOMPATIBILITY.
   166 
   167 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   168 
   169 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   170 cominators for "args".  INCOMPATIBILITY, need to use simplified
   171 Attrib/Method.setup introduced in Isabelle2009.
   172 
   173 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   174 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   175 last resort.  INCOMPATIBILITY.
   176 
   177 * Display.pretty_thm now requires a proper context (cf. former
   178 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   179 or even Display.pretty_thm_without_context as last resort.
   180 INCOMPATIBILITY.
   181 
   182 
   183 *** System ***
   184 
   185 * Support for additional "Isabelle components" via etc/components, see
   186 also the system manual.
   187 
   188 * The isabelle makeall tool now operates on all components with
   189 IsaMakefile, not just hardwired "logics".
   190 
   191 * Discontinued support for Poly/ML 4.x versions.
   192 
   193 * Removed "compress" option from isabelle-process and isabelle usedir;
   194 this is always enabled.
   195 
   196 * More fine-grained control of proof parallelism, cf.
   197 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   198 
   199 
   200 
   201 New in Isabelle2009 (April 2009)
   202 --------------------------------
   203 
   204 *** General ***
   205 
   206 * Simplified main Isabelle executables, with less surprises on
   207 case-insensitive file-systems (such as Mac OS).
   208 
   209   - The main Isabelle tool wrapper is now called "isabelle" instead of
   210     "isatool."
   211 
   212   - The former "isabelle" alias for "isabelle-process" has been
   213     removed (should rarely occur to regular users).
   214 
   215   - The former "isabelle-interface" and its alias "Isabelle" have been
   216     removed (interfaces are now regular Isabelle tools).
   217 
   218 Within scripts and make files, the Isabelle environment variables
   219 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   220 respectively.  (The latter are still available as legacy feature.)
   221 
   222 The old isabelle-interface wrapper could react in confusing ways if
   223 the interface was uninstalled or changed otherwise.  Individual
   224 interface tool configuration is now more explicit, see also the
   225 Isabelle system manual.  In particular, Proof General is now available
   226 via "isabelle emacs".
   227 
   228 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   229 purge installed copies of Isabelle executables and re-run "isabelle
   230 install -p ...", or use symlinks.
   231 
   232 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   233 old ~/isabelle, which was slightly non-standard and apt to cause
   234 surprises on case-insensitive file-systems (such as Mac OS).
   235 
   236 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   237 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   238 care is required when using older releases of Isabelle.  Note that
   239 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   240 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   241 
   242 * Proofs of fully specified statements are run in parallel on
   243 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   244 a regular 4-core machine, if the initial heap space is made reasonably
   245 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   246 
   247 * The main reference manuals ("isar-ref", "implementation", and
   248 "system") have been updated and extended.  Formally checked references
   249 as hyperlinks are now available uniformly.
   250 
   251 
   252 *** Pure ***
   253 
   254 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   255 respects.  The most important changes are listed below.  See the
   256 Tutorial on Locales ("locales" manual) for details.
   257 
   258 - In locale expressions, instantiation replaces renaming.  Parameters
   259 must be declared in a for clause.  To aid compatibility with previous
   260 parameter inheritance, in locale declarations, parameters that are not
   261 'touched' (instantiation position "_" or omitted) are implicitly added
   262 with their syntax at the beginning of the for clause.
   263 
   264 - Syntax from abbreviations and definitions in locales is available in
   265 locale expressions and context elements.  The latter is particularly
   266 useful in locale declarations.
   267 
   268 - More flexible mechanisms to qualify names generated by locale
   269 expressions.  Qualifiers (prefixes) may be specified in locale
   270 expressions, and can be marked as mandatory (syntax: "name!:") or
   271 optional (syntax "name?:").  The default depends for plain "name:"
   272 depends on the situation where a locale expression is used: in
   273 commands 'locale' and 'sublocale' prefixes are optional, in
   274 'interpretation' and 'interpret' prefixes are mandatory.  The old
   275 implicit qualifiers derived from the parameter names of a locale are
   276 no longer generated.
   277 
   278 - Command "sublocale l < e" replaces "interpretation l < e".  The
   279 instantiation clause in "interpretation" and "interpret" (square
   280 brackets) is no longer available.  Use locale expressions.
   281 
   282 - When converting proof scripts, mandatory qualifiers in
   283 'interpretation' and 'interpret' should be retained by default, even
   284 if this is an INCOMPATIBILITY compared to former behavior.  In the
   285 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   286 in locale expressions range over a single locale instance only.
   287 
   288 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   289 In existing theorem specifications replace the includes element by the
   290 respective context elements of the included locale, omitting those
   291 that are already present in the theorem specification.  Multiple
   292 assume elements of a locale should be replaced by a single one
   293 involving the locale predicate.  In the proof body, declarations (most
   294 notably theorems) may be regained by interpreting the respective
   295 locales in the proof context as required (command "interpret").
   296 
   297 If using "includes" in replacement of a target solely because the
   298 parameter types in the theorem are not as general as in the target,
   299 consider declaring a new locale with additional type constraints on
   300 the parameters (context element "constrains").
   301 
   302 - Discontinued "locale (open)".  INCOMPATIBILITY.
   303 
   304 - Locale interpretation commands no longer attempt to simplify goal.
   305 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   306 methods intro_locales and unfold_locales to clarify.
   307 
   308 - Locale interpretation commands no longer accept interpretation
   309 attributes.  INCOMPATIBILITY.
   310 
   311 * Class declaration: so-called "base sort" must not be given in import
   312 list any longer, but is inferred from the specification.  Particularly
   313 in HOL, write
   314 
   315     class foo = ...
   316 
   317 instead of
   318 
   319     class foo = type + ...
   320 
   321 * Class target: global versions of theorems stemming do not carry a
   322 parameter prefix any longer.  INCOMPATIBILITY.
   323 
   324 * Class 'instance' command no longer accepts attached definitions.
   325 INCOMPATIBILITY, use proper 'instantiation' target instead.
   326 
   327 * Recovered hiding of consts, which was accidentally broken in
   328 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   329 makes c inaccessible; consider using ``hide (open) const c'' instead.
   330 
   331 * Slightly more coherent Pure syntax, with updated documentation in
   332 isar-ref manual.  Removed locales meta_term_syntax and
   333 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   334 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   335 directly in regular applications.
   336 
   337 * There is a new syntactic category "float_const" for signed decimal
   338 fractions (e.g. 123.45 or -123.45).
   339 
   340 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   341 interface with 'setup' command instead.
   342 
   343 * Command 'local_setup' is similar to 'setup', but operates on a local
   344 theory context.
   345 
   346 * The 'axiomatization' command now only works within a global theory
   347 context.  INCOMPATIBILITY.
   348 
   349 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   350 hypotheses.  Sorts required in the course of reasoning need to be
   351 covered by the constraints in the initial statement, completed by the
   352 type instance information of the background theory.  Non-trivial sort
   353 hypotheses, which rarely occur in practice, may be specified via
   354 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   355 
   356   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   357 
   358 The result contains an implicit sort hypotheses as before --
   359 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   360 normalization.
   361 
   362 * Generalized Isar history, with support for linear undo, direct state
   363 addressing etc.
   364 
   365 * Changed defaults for unify configuration options:
   366 
   367   unify_trace_bound = 50 (formerly 25)
   368   unify_search_bound = 60 (formerly 30)
   369 
   370 * Different bookkeeping for code equations (INCOMPATIBILITY):
   371 
   372   a) On theory merge, the last set of code equations for a particular
   373      constant is taken (in accordance with the policy applied by other
   374      parts of the code generator framework).
   375 
   376   b) Code equations stemming from explicit declarations (e.g. code
   377      attribute) gain priority over default code equations stemming
   378      from definition, primrec, fun etc.
   379 
   380 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   381 
   382 * Unified theorem tables for both code generators.  Thus [code
   383 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   384 
   385 * Command 'find_consts' searches for constants based on type and name
   386 patterns, e.g.
   387 
   388     find_consts "_ => bool"
   389 
   390 By default, matching is against subtypes, but it may be restricted to
   391 the whole type.  Searching by name is possible.  Multiple queries are
   392 conjunctive and queries may be negated by prefixing them with a
   393 hyphen:
   394 
   395     find_consts strict: "_ => bool" name: "Int" -"int => int"
   396 
   397 * New 'find_theorems' criterion "solves" matches theorems that
   398 directly solve the current goal (modulo higher-order unification).
   399 
   400 * Auto solve feature for main theorem statements: whenever a new goal
   401 is stated, "find_theorems solves" is called; any theorems that could
   402 solve the lemma directly are listed as part of the goal state.
   403 Cf. associated options in Proof General Isabelle settings menu,
   404 enabled by default, with reasonable timeout for pathological cases of
   405 higher-order unification.
   406 
   407 
   408 *** Document preparation ***
   409 
   410 * Antiquotation @{lemma} now imitates a regular terminal proof,
   411 demanding keyword 'by' and supporting the full method expression
   412 syntax just like the Isar command 'by'.
   413 
   414 
   415 *** HOL ***
   416 
   417 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   418 points Main and Complex_Main remain as before.
   419 
   420 * Logic image HOL-Plain provides a minimal HOL with the most important
   421 tools available (inductive, datatype, primrec, ...).  This facilitates
   422 experimentation and tool development.  Note that user applications
   423 (and library theories) should never refer to anything below theory
   424 Main, as before.
   425 
   426 * Logic image HOL-Main stops at theory Main, and thus facilitates
   427 experimentation due to shorter build times.
   428 
   429 * Logic image HOL-NSA contains theories of nonstandard analysis which
   430 were previously part of former HOL-Complex.  Entry point Hyperreal
   431 remains valid, but theories formerly using Complex_Main should now use
   432 new entry point Hypercomplex.
   433 
   434 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   435 Posix processes.  Avoids potentially expensive forking of the ML
   436 process.  New thread-based implementation also works on non-Unix
   437 platforms (Cygwin).  Provers are no longer hardwired, but defined
   438 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   439 commands are covered in the isar-ref manual.
   440 
   441 * Wrapper scripts for remote SystemOnTPTP service allows to use
   442 sledgehammer without local ATP installation (Vampire etc.). Other
   443 provers may be included via suitable ML wrappers, see also
   444 src/HOL/ATP_Linkup.thy.
   445 
   446 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   447 menu.
   448 
   449 * The metis method no longer fails because the theorem is too trivial
   450 (contains the empty clause).
   451 
   452 * The metis method now fails in the usual manner, rather than raising
   453 an exception, if it determines that it cannot prove the theorem.
   454 
   455 * Method "coherent" implements a prover for coherent logic (see also
   456 src/Tools/coherent.ML).
   457 
   458 * Constants "undefined" and "default" replace "arbitrary".  Usually
   459 "undefined" is the right choice to replace "arbitrary", though
   460 logically there is no difference.  INCOMPATIBILITY.
   461 
   462 * Command "value" now integrates different evaluation mechanisms.  The
   463 result of the first successful evaluation mechanism is printed.  In
   464 square brackets a particular named evaluation mechanisms may be
   465 specified (currently, [SML], [code] or [nbe]).  See further
   466 src/HOL/ex/Eval_Examples.thy.
   467 
   468 * Normalization by evaluation now allows non-leftlinear equations.
   469 Declare with attribute [code nbe].
   470 
   471 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   472 as the structured Isar versions "cases" and "induct", cf. the
   473 corresponding "cases" and "induct" attributes.  Mutual induction rules
   474 are now presented as a list of individual projections
   475 (e.g. foo_bar.inducts for types foo and bar); the old format with
   476 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   477 rare situations a different rule is selected --- notably nested tuple
   478 elimination instead of former prod.exhaust: use explicit (case_tac t
   479 rule: prod.exhaust) here.
   480 
   481 * Attributes "cases", "induct", "coinduct" support "del" option.
   482 
   483 * Removed fact "case_split_thm", which duplicates "case_split".
   484 
   485 * The option datatype has been moved to a new theory Option.  Renamed
   486 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   487 
   488 * New predicate "strict_mono" classifies strict functions on partial
   489 orders.  With strict functions on linear orders, reasoning about
   490 (in)equalities is facilitated by theorems "strict_mono_eq",
   491 "strict_mono_less_eq" and "strict_mono_less".
   492 
   493 * Some set operations are now proper qualified constants with
   494 authentic syntax.  INCOMPATIBILITY:
   495 
   496     op Int ~>   Set.Int
   497     op Un ~>    Set.Un
   498     INTER ~>    Set.INTER
   499     UNION ~>    Set.UNION
   500     Inter ~>    Set.Inter
   501     Union ~>    Set.Union
   502     {} ~>       Set.empty
   503     UNIV ~>     Set.UNIV
   504 
   505 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   506 theory Set.
   507 
   508 * Auxiliary class "itself" has disappeared -- classes without any
   509 parameter are treated as expected by the 'class' command.
   510 
   511 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   512 
   513 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   514 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   515 
   516 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   517 method "approximation".  It proves formulas on real values by using
   518 interval arithmetic.  In the formulas are also the transcendental
   519 functions sin, cos, tan, atan, ln, exp and the constant pi are
   520 allowed. For examples see
   521 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   522 
   523 * Theory "Reflection" now resides in HOL/Library.
   524 
   525 * Entry point to Word library now simply named "Word".
   526 INCOMPATIBILITY.
   527 
   528 * Made source layout more coherent with logical distribution
   529 structure:
   530 
   531     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   532     src/HOL/Library/Code_Message.thy ~> src/HOL/
   533     src/HOL/Library/GCD.thy ~> src/HOL/
   534     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   535     src/HOL/Library/Parity.thy ~> src/HOL/
   536     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   537     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   538     src/HOL/Real/Lubs.thy ~> src/HOL/
   539     src/HOL/Real/PReal.thy ~> src/HOL/
   540     src/HOL/Real/Rational.thy ~> src/HOL/
   541     src/HOL/Real/RComplete.thy ~> src/HOL/
   542     src/HOL/Real/RealDef.thy ~> src/HOL/
   543     src/HOL/Real/RealPow.thy ~> src/HOL/
   544     src/HOL/Real/Real.thy ~> src/HOL/
   545     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   546     src/HOL/Complex/Complex.thy ~> src/HOL/
   547     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   548     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   549     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   550     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   551     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   552     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   553     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   554     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   555     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   556     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   557     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   558     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   559     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   560     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   561     src/HOL/Real/Float ~> src/HOL/Library/
   562     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   563     src/HOL/Real/RealVector.thy ~> src/HOL/
   564 
   565     src/HOL/arith_data.ML ~> src/HOL/Tools
   566     src/HOL/hologic.ML ~> src/HOL/Tools
   567     src/HOL/simpdata.ML ~> src/HOL/Tools
   568     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   569     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   570     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   571     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   572     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   573     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   574     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   575 
   576     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   577     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   578     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   579     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   580     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   581     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   582 
   583 * If methods "eval" and "evaluation" encounter a structured proof
   584 state with !!/==>, only the conclusion is evaluated to True (if
   585 possible), avoiding strange error messages.
   586 
   587 * Method "sizechange" automates termination proofs using (a
   588 modification of) the size-change principle.  Requires SAT solver.  See
   589 src/HOL/ex/Termination.thy for examples.
   590 
   591 * Simplifier: simproc for let expressions now unfolds if bound
   592 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   593 
   594 * Method "arith": Linear arithmetic now ignores all inequalities when
   595 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   596 
   597 * New attribute "arith" for facts that should always be used
   598 automatically by arithmetic. It is intended to be used locally in
   599 proofs, e.g.
   600 
   601   assumes [arith]: "x > 0"
   602 
   603 Global usage is discouraged because of possible performance impact.
   604 
   605 * New classes "top" and "bot" with corresponding operations "top" and
   606 "bot" in theory Orderings; instantiation of class "complete_lattice"
   607 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   608 
   609 * Changed definition lemma "less_fun_def" in order to provide an
   610 instance for preorders on functions; use lemma "less_le" instead.
   611 INCOMPATIBILITY.
   612 
   613 * Theory Orderings: class "wellorder" moved here, with explicit
   614 induction rule "less_induct" as assumption.  For instantiation of
   615 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   616 INCOMPATIBILITY.
   617 
   618 * Theory Orderings: added class "preorder" as superclass of "order".
   619 INCOMPATIBILITY: Instantiation proofs for order, linorder
   620 etc. slightly changed.  Some theorems named order_class.* now named
   621 preorder_class.*.
   622 
   623 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   624 "diag" to "Id_on".
   625 
   626 * Theory Finite_Set: added a new fold combinator of type
   627 
   628   ('a => 'b => 'b) => 'b => 'a set => 'b
   629 
   630 Occasionally this is more convenient than the old fold combinator
   631 which is now defined in terms of the new one and renamed to
   632 fold_image.
   633 
   634 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   635 and "ring_simps" have been replaced by "algebra_simps" (which can be
   636 extended with further lemmas!).  At the moment both still exist but
   637 the former will disappear at some point.
   638 
   639 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   640 class recpower.  Type-specific simp rules for various recpower types
   641 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   642 
   643 rat_power_0    -> power_0
   644 rat_power_Suc  -> power_Suc
   645 realpow_0      -> power_0
   646 realpow_Suc    -> power_Suc
   647 complexpow_0   -> power_0
   648 complexpow_Suc -> power_Suc
   649 power_poly_0   -> power_0
   650 power_poly_Suc -> power_Suc
   651 
   652 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   653 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   654 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   655 of lemmas from Divides has been generalized from nat to class
   656 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   657 renames resulting from duplicate elimination:
   658 
   659     dvd_def_mod ~>          dvd_eq_mod_eq_0
   660     zero_dvd_iff ~>         dvd_0_left_iff
   661     dvd_0 ~>                dvd_0_right
   662     DIVISION_BY_ZERO_DIV ~> div_by_0
   663     DIVISION_BY_ZERO_MOD ~> mod_by_0
   664     mult_div ~>             div_mult_self2_is_id
   665     mult_mod ~>             mod_mult_self2_is_0
   666 
   667 * Theory IntDiv: removed many lemmas that are instances of class-based
   668 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   669 rename old lemmas as follows:
   670 
   671 dvd_diff               -> nat_dvd_diff
   672 dvd_zminus_iff         -> dvd_minus_iff
   673 mod_add1_eq            -> mod_add_eq
   674 mod_mult1_eq           -> mod_mult_right_eq
   675 mod_mult1_eq'          -> mod_mult_left_eq
   676 mod_mult_distrib_mod   -> mod_mult_eq
   677 nat_mod_add_left_eq    -> mod_add_left_eq
   678 nat_mod_add_right_eq   -> mod_add_right_eq
   679 nat_mod_div_trivial    -> mod_div_trivial
   680 nat_mod_mod_trivial    -> mod_mod_trivial
   681 zdiv_zadd_self1        -> div_add_self1
   682 zdiv_zadd_self2        -> div_add_self2
   683 zdiv_zmult_self1       -> div_mult_self2_is_id
   684 zdiv_zmult_self2       -> div_mult_self1_is_id
   685 zdvd_triv_left         -> dvd_triv_left
   686 zdvd_triv_right        -> dvd_triv_right
   687 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   688 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   689 zmod_zadd_left_eq      -> mod_add_left_eq
   690 zmod_zadd_right_eq     -> mod_add_right_eq
   691 zmod_zadd_self1        -> mod_add_self1
   692 zmod_zadd_self2        -> mod_add_self2
   693 zmod_zadd1_eq          -> mod_add_eq
   694 zmod_zdiff1_eq         -> mod_diff_eq
   695 zmod_zdvd_zmod         -> mod_mod_cancel
   696 zmod_zmod_cancel       -> mod_mod_cancel
   697 zmod_zmult_self1       -> mod_mult_self2_is_0
   698 zmod_zmult_self2       -> mod_mult_self1_is_0
   699 zmod_1                 -> mod_by_1
   700 zdiv_1                 -> div_by_1
   701 zdvd_abs1              -> abs_dvd_iff
   702 zdvd_abs2              -> dvd_abs_iff
   703 zdvd_refl              -> dvd_refl
   704 zdvd_trans             -> dvd_trans
   705 zdvd_zadd              -> dvd_add
   706 zdvd_zdiff             -> dvd_diff
   707 zdvd_zminus_iff        -> dvd_minus_iff
   708 zdvd_zminus2_iff       -> minus_dvd_iff
   709 zdvd_zmultD            -> dvd_mult_right
   710 zdvd_zmultD2           -> dvd_mult_left
   711 zdvd_zmult_mono        -> mult_dvd_mono
   712 zdvd_0_right           -> dvd_0_right
   713 zdvd_0_left            -> dvd_0_left_iff
   714 zdvd_1_left            -> one_dvd
   715 zminus_dvd_iff         -> minus_dvd_iff
   716 
   717 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   718 
   719 * The real numbers offer decimal input syntax: 12.34 is translated
   720 into 1234/10^2. This translation is not reversed upon output.
   721 
   722 * Theory Library/Polynomial defines an abstract type 'a poly of
   723 univariate polynomials with coefficients of type 'a.  In addition to
   724 the standard ring operations, it also supports div and mod.  Code
   725 generation is also supported, using list-style constructors.
   726 
   727 * Theory Library/Inner_Product defines a class of real_inner for real
   728 inner product spaces, with an overloaded operation inner :: 'a => 'a
   729 => real.  Class real_inner is a subclass of real_normed_vector from
   730 theory RealVector.
   731 
   732 * Theory Library/Product_Vector provides instances for the product
   733 type 'a * 'b of several classes from RealVector and Inner_Product.
   734 Definitions of addition, subtraction, scalar multiplication, norms,
   735 and inner products are included.
   736 
   737 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   738 addition to the field operations, numerals and case syntax are also
   739 supported.
   740 
   741 * Theory Library/Diagonalize provides constructive version of Cantor's
   742 first diagonalization argument.
   743 
   744 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   745 zlcm (for int); carried together from various gcd/lcm developements in
   746 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   747 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   748 may recover tupled syntax as follows:
   749 
   750     hide (open) const gcd
   751     abbreviation gcd where
   752       "gcd == (%(a, b). GCD.gcd a b)"
   753     notation (output)
   754       GCD.gcd ("gcd '(_, _')")
   755 
   756 The same works for lcm, zgcd, zlcm.
   757 
   758 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   759 instantiations for algebraic structures.  Removed some duplicate
   760 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   761 
   762 * ML antiquotation @{code} takes a constant as argument and generates
   763 corresponding code in background and inserts name of the corresponding
   764 resulting ML value/function/datatype constructor binding in place.
   765 All occurrences of @{code} with a single ML block are generated
   766 simultaneously.  Provides a generic and safe interface for
   767 instrumentalizing code generation.  See
   768 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   769 In future you ought to refrain from ad-hoc compiling generated SML
   770 code on the ML toplevel.  Note that (for technical reasons) @{code}
   771 cannot refer to constants for which user-defined serializations are
   772 set.  Refer to the corresponding ML counterpart directly in that
   773 cases.
   774 
   775 * Command 'rep_datatype': instead of theorem names the command now
   776 takes a list of terms denoting the constructors of the type to be
   777 represented as datatype.  The characteristic theorems have to be
   778 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   779 have disappeared in favour of existing ones:
   780 
   781     unit_induct                 ~> unit.induct
   782     prod_induct                 ~> prod.induct
   783     sum_induct                  ~> sum.induct
   784     Suc_Suc_eq                  ~> nat.inject
   785     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   786 
   787 
   788 *** HOL-Algebra ***
   789 
   790 * New locales for orders and lattices where the equivalence relation
   791 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   792 locales use a record structure with field eq for the equivalence.
   793 
   794 * New theory of factorial domains.
   795 
   796 * Units_l_inv and Units_r_inv are now simp rules by default.
   797 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   798 and/or r_inv will now also require deletion of these lemmas.
   799 
   800 * Renamed the following theorems, INCOMPATIBILITY:
   801 
   802 UpperD ~> Upper_memD
   803 LowerD ~> Lower_memD
   804 least_carrier ~> least_closed
   805 greatest_carrier ~> greatest_closed
   806 greatest_Lower_above ~> greatest_Lower_below
   807 one_zero ~> carrier_one_zero
   808 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   809 
   810 
   811 *** HOL-Nominal ***
   812 
   813 * Nominal datatypes can now contain type-variables.
   814 
   815 * Commands 'nominal_inductive' and 'equivariance' work with local
   816 theory targets.
   817 
   818 * Nominal primrec can now works with local theory targets and its
   819 specification syntax now conforms to the general format as seen in
   820 'inductive' etc.
   821 
   822 * Method "perm_simp" honours the standard simplifier attributes
   823 (no_asm), (no_asm_use) etc.
   824 
   825 * The new predicate #* is defined like freshness, except that on the
   826 left hand side can be a set or list of atoms.
   827 
   828 * Experimental command 'nominal_inductive2' derives strong induction
   829 principles for inductive definitions.  In contrast to
   830 'nominal_inductive', which can only deal with a fixed number of
   831 binders, it can deal with arbitrary expressions standing for sets of
   832 atoms to be avoided.  The only inductive definition we have at the
   833 moment that needs this generalisation is the typing rule for Lets in
   834 the algorithm W:
   835 
   836  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   837  -----------------------------------------------------------------
   838          Gamma |- Let x be t1 in t2 : T2
   839 
   840 In this rule one wants to avoid all the binders that are introduced by
   841 "close Gamma T1".  We are looking for other examples where this
   842 feature might be useful.  Please let us know.
   843 
   844 
   845 *** HOLCF ***
   846 
   847 * Reimplemented the simplification procedure for proving continuity
   848 subgoals.  The new simproc is extensible; users can declare additional
   849 continuity introduction rules with the attribute [cont2cont].
   850 
   851 * The continuity simproc now uses a different introduction rule for
   852 solving continuity subgoals on terms with lambda abstractions.  In
   853 some rare cases the new simproc may fail to solve subgoals that the
   854 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   855 Potential INCOMPATIBILITY.
   856 
   857 * Command 'fixrec': specification syntax now conforms to the general
   858 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   859 examples.  INCOMPATIBILITY.
   860 
   861 
   862 *** ZF ***
   863 
   864 * Proof of Zorn's Lemma for partial orders.
   865 
   866 
   867 *** ML ***
   868 
   869 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   870 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   871 depends on multithreading, so timouts will not work before Poly/ML
   872 5.2.1!
   873 
   874 * High-level support for concurrent ML programming, see
   875 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   876 particularly convenient to organize independent functional
   877 computations.  The concept of "synchronized variables" provides a
   878 higher-order interface for components with shared state, avoiding the
   879 delicate details of mutexes and condition variables.  (Requires
   880 Poly/ML 5.2.1 or later.)
   881 
   882 * ML bindings produced via Isar commands are stored within the Isar
   883 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   884 become thread-safe and work with undo as expected (concerning
   885 top-level bindings, not side-effects on global references).
   886 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   887 compiler at runtime; really global bindings need to be given outside a
   888 theory.  (Requires Poly/ML 5.2 or later.)
   889 
   890 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   891 context.  Top-level ML bindings are stored within the proof context in
   892 a purely sequential fashion, disregarding the nested proof structure.
   893 ML bindings introduced by 'ML_prf' are discarded at the end of the
   894 proof.  (Requires Poly/ML 5.2 or later.)
   895 
   896 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   897 and Method.setup, as well as Isar commands 'attribute_setup' and
   898 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   899 existing code accordingly, or use plain 'setup' together with old
   900 Method.add_method.
   901 
   902 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   903 to 'a -> thm, while results are always tagged with an authentic oracle
   904 name.  The Isar command 'oracle' is now polymorphic, no argument type
   905 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   906 accordingly.  Note that extra performance may be gained by producing
   907 the cterm carefully, avoiding slow Thm.cterm_of.
   908 
   909 * Simplified interface for defining document antiquotations via
   910 ThyOutput.antiquotation, ThyOutput.output, and optionally
   911 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   912 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   913 examples.
   914 
   915 * More systematic treatment of long names, abstract name bindings, and
   916 name space operations.  Basic operations on qualified names have been
   917 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   918 Long_Name.append.  Old type bstring has been mostly replaced by
   919 abstract type binding (see structure Binding), which supports precise
   920 qualification by packages and local theory targets, as well as proper
   921 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   922 bstring values into Binding.name, or better pass through abstract
   923 bindings everywhere.  See further src/Pure/General/long_name.ML,
   924 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   925 
   926 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   927 LocalTheory.note etc.) now refer to the *full* internal name, not the
   928 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   929 
   930 * Disposed old type and term read functions (Sign.read_def_typ,
   931 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   932 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   933 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   934 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   935 resort for legacy applications.
   936 
   937 * Disposed old declarations, tactics, tactic combinators that refer to
   938 the simpset or claset of an implicit theory (such as Addsimps,
   939 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   940 embedded ML text, or local_simpset_of with a proper context passed as
   941 explicit runtime argument.
   942 
   943 * Rules and tactics that read instantiations (read_instantiate,
   944 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   945 context, which is required for parsing and type-checking.  Moreover,
   946 the variables are specified as plain indexnames, not string encodings
   947 thereof.  INCOMPATIBILITY.
   948 
   949 * Generic Toplevel.add_hook interface allows to analyze the result of
   950 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   951 for theorem dependency output of transactions resulting in a new
   952 theory state.
   953 
   954 * ML antiquotations: block-structured compilation context indicated by
   955 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   956 
   957   @{binding name}                         - basic name binding
   958   @{let ?pat = term}                      - term abbreviation (HO matching)
   959   @{note name = fact}                     - fact abbreviation
   960   @{thm fact}                             - singleton fact (with attributes)
   961   @{thms fact}                            - general fact (with attributes)
   962   @{lemma prop by method}                 - singleton goal
   963   @{lemma prop by meth1 meth2}            - singleton goal
   964   @{lemma prop1 ... propN by method}      - general goal
   965   @{lemma prop1 ... propN by meth1 meth2} - general goal
   966   @{lemma (open) ...}                     - open derivation
   967 
   968 
   969 *** System ***
   970 
   971 * The Isabelle "emacs" tool provides a specific interface to invoke
   972 Proof General / Emacs, with more explicit failure if that is not
   973 installed (the old isabelle-interface script silently falls back on
   974 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   975 installation location of the Proof General distribution.
   976 
   977 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   978 the Isabelle process into a JVM/Scala application.  See
   979 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   980 process wrapper has been discontinued.)
   981 
   982 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   983 
   984 * Various status messages (with exact source position information) are
   985 emitted, if proper markup print mode is enabled.  This allows
   986 user-interface components to provide detailed feedback on internal
   987 prover operations.
   988 
   989 
   990 
   991 New in Isabelle2008 (June 2008)
   992 -------------------------------
   993 
   994 *** General ***
   995 
   996 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   997 and updated, with formally checked references as hyperlinks.
   998 
   999 * Theory loader: use_thy (and similar operations) no longer set the
  1000 implicit ML context, which was occasionally hard to predict and in
  1001 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1002 provides a proper context already.
  1003 
  1004 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1005 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1006 'use' within a theory file will do the job.
  1007 
  1008 * Name space merge now observes canonical order, i.e. the second space
  1009 is inserted into the first one, while existing entries in the first
  1010 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1011 swap theory imports.
  1012 
  1013 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1014 INCOMPATIBILITY in identifier syntax etc.
  1015 
  1016 * Outer syntax: string tokens no longer admit escaped white space,
  1017 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1018 white space without escapes.
  1019 
  1020 * Outer syntax: string tokens may contain arbitrary character codes
  1021 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1022 "foo_bar".
  1023 
  1024 
  1025 *** Pure ***
  1026 
  1027 * Context-dependent token translations.  Default setup reverts locally
  1028 fixed variables, and adds hilite markup for undeclared frees.
  1029 
  1030 * Unused theorems can be found using the new command 'unused_thms'.
  1031 There are three ways of invoking it:
  1032 
  1033 (1) unused_thms
  1034      Only finds unused theorems in the current theory.
  1035 
  1036 (2) unused_thms thy_1 ... thy_n -
  1037      Finds unused theorems in the current theory and all of its ancestors,
  1038      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1039 
  1040 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1041      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1042      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1043      their ancestors.
  1044 
  1045 In order to increase the readability of the list produced by
  1046 unused_thms, theorems that have been created by a particular instance
  1047 of a theory command such as 'inductive' or 'function' are considered
  1048 to belong to the same "group", meaning that if at least one theorem in
  1049 this group is used, the other theorems in the same group are no longer
  1050 reported as unused.  Moreover, if all theorems in the group are
  1051 unused, only one theorem in the group is displayed.
  1052 
  1053 Note that proof objects have to be switched on in order for
  1054 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1055 usually the case when using Proof General with the default settings).
  1056 
  1057 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1058 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1059 duplicate fact bindings, or even accidental fact duplications.  Note
  1060 that tools may maintain dynamically scoped facts systematically, using
  1061 PureThy.add_thms_dynamic.
  1062 
  1063 * Command 'hide' now allows to hide from "fact" name space as well.
  1064 
  1065 * Eliminated destructive theorem database, simpset, claset, and
  1066 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1067 update of theories within ML code.
  1068 
  1069 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1070 INCOMPATIBILITY, object-logics depending on former Pure require
  1071 additional setup PureThy.old_appl_syntax_setup; object-logics
  1072 depending on former CPure need to refer to Pure.
  1073 
  1074 * Commands 'use' and 'ML' are now purely functional, operating on
  1075 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1076 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1077 INCOMPATIBILITY.
  1078 
  1079 * Command 'setup': discontinued implicit version with ML reference.
  1080 
  1081 * Instantiation target allows for simultaneous specification of class
  1082 instance operations together with an instantiation proof.
  1083 Type-checking phase allows to refer to class operations uniformly.
  1084 See src/HOL/Complex/Complex.thy for an Isar example and
  1085 src/HOL/Library/Eval.thy for an ML example.
  1086 
  1087 * Indexing of literal facts: be more serious about including only
  1088 facts from the visible specification/proof context, but not the
  1089 background context (locale etc.).  Affects `prop` notation and method
  1090 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1091 situations.
  1092 
  1093 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1094 "(open)" option, which used to expose internal bound variables to the
  1095 proof text.
  1096 
  1097 * Isar statements: removed obsolete case "rule_context".
  1098 INCOMPATIBILITY, better use explicit fixes/assumes.
  1099 
  1100 * Locale proofs: default proof step now includes 'unfold_locales';
  1101 hence 'proof' without argument may be used to unfold locale
  1102 predicates.
  1103 
  1104 
  1105 *** Document preparation ***
  1106 
  1107 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1108 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1109 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1110 spot); renamed link color from "darkblue" to "linkcolor" (default
  1111 value unchanged, can be redefined via \definecolor); no longer sets
  1112 "a4paper" option (unnecessary or even intrusive).
  1113 
  1114 * Antiquotation @{lemma A method} proves proposition A by the given
  1115 method (either a method name or a method name plus (optional) method
  1116 arguments in parentheses) and prints A just like @{prop A}.
  1117 
  1118 
  1119 *** HOL ***
  1120 
  1121 * New primrec package.  Specification syntax conforms in style to
  1122 definition/function/....  No separate induction rule is provided.  The
  1123 "primrec" command distinguishes old-style and new-style specifications
  1124 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1125 When adjusting theories, beware: constants stemming from new-style
  1126 primrec specifications have authentic syntax.
  1127 
  1128 * Metis prover is now an order of magnitude faster, and also works
  1129 with multithreading.
  1130 
  1131 * Metis: the maximum number of clauses that can be produced from a
  1132 theorem is now given by the attribute max_clauses.  Theorems that
  1133 exceed this number are ignored, with a warning printed.
  1134 
  1135 * Sledgehammer no longer produces structured proofs by default. To
  1136 enable, declare [[sledgehammer_full = true]].  Attributes
  1137 reconstruction_modulus, reconstruction_sorts renamed
  1138 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1139 
  1140 * Method "induct_scheme" derives user-specified induction rules
  1141 from well-founded induction and completeness of patterns. This factors
  1142 out some operations that are done internally by the function package
  1143 and makes them available separately.  See
  1144 src/HOL/ex/Induction_Scheme.thy for examples.
  1145 
  1146 * More flexible generation of measure functions for termination
  1147 proofs: Measure functions can be declared by proving a rule of the
  1148 form "is_measure f" and giving it the [measure_function] attribute.
  1149 The "is_measure" predicate is logically meaningless (always true), and
  1150 just guides the heuristic.  To find suitable measure functions, the
  1151 termination prover sets up the goal "is_measure ?f" of the appropriate
  1152 type and generates all solutions by prolog-style backwards proof using
  1153 the declared rules.
  1154 
  1155 This setup also deals with rules like 
  1156 
  1157   "is_measure f ==> is_measure (list_size f)"
  1158 
  1159 which accommodates nested datatypes that recurse through lists.
  1160 Similar rules are predeclared for products and option types.
  1161 
  1162 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1163 
  1164   INCOMPATIBILITIES:
  1165 
  1166   - Definitions of overloaded constants on sets have to be replaced by
  1167     definitions on => and bool.
  1168 
  1169   - Some definitions of overloaded operators on sets can now be proved
  1170     using the definitions of the operators on => and bool.  Therefore,
  1171     the following theorems have been renamed:
  1172 
  1173       subset_def   -> subset_eq
  1174       psubset_def  -> psubset_eq
  1175       set_diff_def -> set_diff_eq
  1176       Compl_def    -> Compl_eq
  1177       Sup_set_def  -> Sup_set_eq
  1178       Inf_set_def  -> Inf_set_eq
  1179       sup_set_def  -> sup_set_eq
  1180       inf_set_def  -> inf_set_eq
  1181 
  1182   - Due to the incompleteness of the HO unification algorithm, some
  1183     rules such as subst may require manual instantiation, if some of
  1184     the unknowns in the rule is a set.
  1185 
  1186   - Higher order unification and forward proofs:
  1187     The proof pattern
  1188 
  1189       have "P (S::'a set)" <...>
  1190       then have "EX S. P S" ..
  1191 
  1192     no longer works (due to the incompleteness of the HO unification
  1193     algorithm) and must be replaced by the pattern
  1194 
  1195       have "EX S. P S"
  1196       proof
  1197         show "P S" <...>
  1198       qed
  1199 
  1200   - Calculational reasoning with subst (or similar rules):
  1201     The proof pattern
  1202 
  1203       have "P (S::'a set)" <...>
  1204       also have "S = T" <...>
  1205       finally have "P T" .
  1206 
  1207     no longer works (for similar reasons as the previous example) and
  1208     must be replaced by something like
  1209 
  1210       have "P (S::'a set)" <...>
  1211       moreover have "S = T" <...>
  1212       ultimately have "P T" by simp
  1213 
  1214   - Tactics or packages written in ML code:
  1215     Code performing pattern matching on types via
  1216 
  1217       Type ("set", [T]) => ...
  1218 
  1219     must be rewritten. Moreover, functions like strip_type or
  1220     binder_types no longer return the right value when applied to a
  1221     type of the form
  1222 
  1223       T1 => ... => Tn => U => bool
  1224 
  1225     rather than
  1226 
  1227       T1 => ... => Tn => U set
  1228 
  1229 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1230 Wellfounded_Relations to theory Wellfounded.
  1231 
  1232 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1233 
  1234 * Class finite no longer treats UNIV as class parameter.  Use class
  1235 enum from theory Library/Enum instead to achieve a similar effect.
  1236 INCOMPATIBILITY.
  1237 
  1238 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1239 and "Cons".  INCOMPATIBILITY.
  1240 
  1241 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1242 Potential INCOMPATIBILITY.
  1243 
  1244 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1245 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1246 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1247 
  1248 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1249 the same name in theory Orderings:
  1250 
  1251   less_trans
  1252   less_linear
  1253   le_imp_less_or_eq
  1254   le_less_trans
  1255   less_le_trans
  1256   less_not_sym
  1257   less_asym
  1258 
  1259 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1260 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1261 and different variable names.
  1262 
  1263 * Library/Option_ord.thy: Canonical order on option type.
  1264 
  1265 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1266 finite maps.
  1267 
  1268 * Library/Countable.thy: Type class for countable types.
  1269 
  1270 * Theory Int: The representation of numerals has changed.  The infix
  1271 operator BIT and the bit datatype with constructors B0 and B1 have
  1272 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1273 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1274 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1275 accordingly.
  1276 
  1277 * Theory Nat: definition of <= and < on natural numbers no longer
  1278 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1279 le_def and less_def have disappeared.  Consider lemmas not_less
  1280 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1281 
  1282 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1283 (whose purpose mainly is for various fold_set functionals) have been
  1284 abandoned in favor of the existing algebraic classes
  1285 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1286 lower_semilattice (resp. upper_semilattice) and linorder.
  1287 INCOMPATIBILITY.
  1288 
  1289 * Theory Transitive_Closure: induct and cases rules now declare proper
  1290 case_names ("base" and "step").  INCOMPATIBILITY.
  1291 
  1292 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1293 lattices.  The form set-specific version is available as
  1294 Inductive.lfp_ordinal_induct_set.
  1295 
  1296 * Renamed theorems "power.simps" to "power_int.simps".
  1297 INCOMPATIBILITY.
  1298 
  1299 * Class semiring_div provides basic abstract properties of semirings
  1300 with division and modulo operations.  Subsumes former class dvd_mod.
  1301 
  1302 * Merged theories IntDef, Numeral and IntArith into unified theory
  1303 Int.  INCOMPATIBILITY.
  1304 
  1305 * Theory Library/Code_Index: type "index" now represents natural
  1306 numbers rather than integers.  INCOMPATIBILITY.
  1307 
  1308 * New class "uminus" with operation "uminus" (split of from class
  1309 "minus" which now only has operation "minus", binary).
  1310 INCOMPATIBILITY.
  1311 
  1312 * Constants "card", "internal_split", "option_map" now with authentic
  1313 syntax.  INCOMPATIBILITY.
  1314 
  1315 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1316 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1317 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1318 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1319 Sup_set_def, le_def, less_def, option_map_def now with object
  1320 equality.  INCOMPATIBILITY.
  1321 
  1322 * Records. Removed K_record, and replaced it by pure lambda term
  1323 %x. c. The simplifier setup is now more robust against eta expansion.
  1324 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1325 
  1326 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1327 
  1328 * Library/ListVector: new theory of arithmetic vector operations.
  1329 
  1330 * Library/Order_Relation: new theory of various orderings as sets of
  1331 pairs.  Defines preorders, partial orders, linear orders and
  1332 well-orders on sets and on types.
  1333 
  1334 
  1335 *** ZF ***
  1336 
  1337 * Renamed some theories to allow to loading both ZF and HOL in the
  1338 same session:
  1339 
  1340   Datatype  -> Datatype_ZF
  1341   Inductive -> Inductive_ZF
  1342   Int       -> Int_ZF
  1343   IntDiv    -> IntDiv_ZF
  1344   Nat       -> Nat_ZF
  1345   List      -> List_ZF
  1346   Main      -> Main_ZF
  1347 
  1348 INCOMPATIBILITY: ZF theories that import individual theories below
  1349 Main might need to be adapted.  Regular theory Main is still
  1350 available, as trivial extension of Main_ZF.
  1351 
  1352 
  1353 *** ML ***
  1354 
  1355 * ML within Isar: antiquotation @{const name} or @{const
  1356 name(typargs)} produces statically-checked Const term.
  1357 
  1358 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1359 (of the same name).  Removed obsolete print command.
  1360 
  1361 * Removed obsolete "use_legacy_bindings" function.
  1362 
  1363 * The ``print mode'' is now a thread-local value derived from a global
  1364 template (the former print_mode reference), thus access becomes
  1365 non-critical.  The global print_mode reference is for session
  1366 management only; user-code should use print_mode_value,
  1367 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1368 
  1369 * Functions system/system_out provide a robust way to invoke external
  1370 shell commands, with propagation of interrupts (requires Poly/ML
  1371 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1372 
  1373 
  1374 *** System ***
  1375 
  1376 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1377 in accordance with Proof General 3.7, which prefers GNU emacs.
  1378 
  1379 * isatool tty runs Isabelle process with plain tty interaction;
  1380 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1381 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1382 
  1383 * isatool browser now works with Cygwin as well, using general
  1384 "javapath" function defined in Isabelle process environment.
  1385 
  1386 * YXML notation provides a simple and efficient alternative to
  1387 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1388 isatool yxml as described in the Isabelle system manual.
  1389 
  1390 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1391 provides general wrapper for managing an Isabelle process in a robust
  1392 fashion, with ``cooked'' output from stdin/stderr.
  1393 
  1394 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1395 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1396 
  1397 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1398 way of changing the user's settings is via
  1399 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1400 script.
  1401 
  1402 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1403 cores of the underlying machine, which is a good starting point for
  1404 optimal performance tuning.  The corresponding usedir option -M allows
  1405 "max" as an alias for "0".  WARNING: does not work on certain versions
  1406 of Mac OS (with Poly/ML 5.1).
  1407 
  1408 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1409 adverse effect of Isabelle flooding interactive front-ends (notably
  1410 ProofGeneral / XEmacs).
  1411 
  1412 
  1413 
  1414 New in Isabelle2007 (November 2007)
  1415 -----------------------------------
  1416 
  1417 *** General ***
  1418 
  1419 * More uniform information about legacy features, notably a
  1420 warning/error of "Legacy feature: ...", depending on the state of the
  1421 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1422 legacy features will disappear eventually.
  1423 
  1424 * Theory syntax: the header format ``theory A = B + C:'' has been
  1425 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1426 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1427 
  1428 * Theory syntax: the old non-Isar theory file format has been
  1429 discontinued altogether.  Note that ML proof scripts may still be used
  1430 with Isar theories; migration is usually quite simple with the ML
  1431 function use_legacy_bindings.  INCOMPATIBILITY.
  1432 
  1433 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1434 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1435 quotes.
  1436 
  1437 * Theory loader: be more serious about observing the static theory
  1438 header specifications (including optional directories), but not the
  1439 accidental file locations of previously successful loads.  The strict
  1440 update policy of former update_thy is now already performed by
  1441 use_thy, so the former has been removed; use_thys updates several
  1442 theories simultaneously, just as 'imports' within a theory header
  1443 specification, but without merging the results.  Potential
  1444 INCOMPATIBILITY: may need to refine theory headers and commands
  1445 ROOT.ML which depend on load order.
  1446 
  1447 * Theory loader: optional support for content-based file
  1448 identification, instead of the traditional scheme of full physical
  1449 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1450 (cf. the system manual).  The new scheme allows to work with
  1451 non-finished theories in persistent session images, such that source
  1452 files may be moved later on without requiring reloads.
  1453 
  1454 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1455 file (with the same base name as the theory) are considered a legacy
  1456 feature, which will disappear eventually. Even now, the theory loader
  1457 no longer maintains dependencies on such files.
  1458 
  1459 * Syntax: the scope for resolving ambiguities via type-inference is
  1460 now limited to individual terms, instead of whole simultaneous
  1461 specifications as before. This greatly reduces the complexity of the
  1462 syntax module and improves flexibility by separating parsing and
  1463 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1464 'fixes' etc.) are required in rare situations.
  1465 
  1466 * Syntax: constants introduced by new-style packages ('definition',
  1467 'abbreviation' etc.) are passed through the syntax module in
  1468 ``authentic mode''. This means that associated mixfix annotations
  1469 really stick to such constants, independently of potential name space
  1470 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1471 trees are represented slightly differently, may need to adapt syntax
  1472 translations accordingly. Use CONST marker in 'translations' and
  1473 @{const_syntax} antiquotation in 'parse_translation' etc.
  1474 
  1475 * Legacy goal package: reduced interface to the bare minimum required
  1476 to keep existing proof scripts running.  Most other user-level
  1477 functions are now part of the OldGoals structure, which is *not* open
  1478 by default (consider isatool expandshort before open OldGoals).
  1479 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1480 these tend to cause confusion about the actual goal (!) context being
  1481 used here, which is not necessarily the same as the_context().
  1482 
  1483 * Command 'find_theorems': supports "*" wild-card in "name:"
  1484 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1485 support a specific search form (see ProofGeneral/CHANGES).
  1486 
  1487 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1488 by default, which means that "prems" (and also "fixed variables") are
  1489 suppressed from proof state output.  Note that the ProofGeneral
  1490 settings mechanism allows to change and save options persistently, but
  1491 older versions of Isabelle will fail to start up if a negative prems
  1492 limit is imposed.
  1493 
  1494 * Local theory targets may be specified by non-nested blocks of
  1495 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1496 contain definitions, theorems etc., including any derived mechanism
  1497 that has been implemented on top of these primitives.  This concept
  1498 generalizes the existing ``theorem (in ...)'' towards more versatility
  1499 and scalability.
  1500 
  1501 * Proof General interface: proper undo of final 'end' command;
  1502 discontinued Isabelle/classic mode (ML proof scripts).
  1503 
  1504 
  1505 *** Document preparation ***
  1506 
  1507 * Added antiquotation @{theory name} which prints the given name,
  1508 after checking that it refers to a valid ancestor theory in the
  1509 current context.
  1510 
  1511 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1512 check the given source text as ML type/structure, printing verbatim.
  1513 
  1514 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1515 "c args == rhs" given in the current context.  (Any number of
  1516 arguments may be given on the LHS.)
  1517 
  1518 
  1519 *** Pure ***
  1520 
  1521 * The 'class' package offers a combination of axclass and locale to
  1522 achieve Haskell-like type classes in Isabelle.  Definitions and
  1523 theorems within a class context produce both relative results (with
  1524 implicit parameters according to the locale context), and polymorphic
  1525 constants with qualified polymorphism (according to the class
  1526 context).  Within the body context of a 'class' target, a separate
  1527 syntax layer ("user space type system") takes care of converting
  1528 between global polymorphic consts and internal locale representation.
  1529 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1530 "isatool doc classes" provides a tutorial.
  1531 
  1532 * Generic code generator framework allows to generate executable
  1533 code for ML and Haskell (including Isabelle classes).  A short usage
  1534 sketch:
  1535 
  1536     internal compilation:
  1537         export_code <list of constants (term syntax)> in SML
  1538     writing SML code to a file:
  1539         export_code <list of constants (term syntax)> in SML <filename>
  1540     writing OCaml code to a file:
  1541         export_code <list of constants (term syntax)> in OCaml <filename>
  1542     writing Haskell code to a bunch of files:
  1543         export_code <list of constants (term syntax)> in Haskell <filename>
  1544 
  1545     evaluating closed propositions to True/False using code generation:
  1546         method ``eval''
  1547 
  1548 Reasonable default setup of framework in HOL.
  1549 
  1550 Theorem attributs for selecting and transforming function equations theorems:
  1551 
  1552     [code fun]:        select a theorem as function equation for a specific constant
  1553     [code fun del]:    deselect a theorem as function equation for a specific constant
  1554     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1555     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1556 
  1557 User-defined serializations (target in {SML, OCaml, Haskell}):
  1558 
  1559     code_const <and-list of constants (term syntax)>
  1560       {(target) <and-list of const target syntax>}+
  1561 
  1562     code_type <and-list of type constructors>
  1563       {(target) <and-list of type target syntax>}+
  1564 
  1565     code_instance <and-list of instances>
  1566       {(target)}+
  1567         where instance ::= <type constructor> :: <class>
  1568 
  1569     code_class <and_list of classes>
  1570       {(target) <and-list of class target syntax>}+
  1571         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1572 
  1573 code_instance and code_class only are effective to target Haskell.
  1574 
  1575 For example usage see src/HOL/ex/Codegenerator.thy and
  1576 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1577 generation from Isabelle/HOL theories is available via "isatool doc
  1578 codegen".
  1579 
  1580 * Code generator: consts in 'consts_code' Isar commands are now
  1581 referred to by usual term syntax (including optional type
  1582 annotations).
  1583 
  1584 * Command 'no_translations' removes translation rules from theory
  1585 syntax.
  1586 
  1587 * Overloaded definitions are now actually checked for acyclic
  1588 dependencies.  The overloading scheme is slightly more general than
  1589 that of Haskell98, although Isabelle does not demand an exact
  1590 correspondence to type class and instance declarations.
  1591 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1592 exotic versions of overloading -- at the discretion of the user!
  1593 
  1594 Polymorphic constants are represented via type arguments, i.e. the
  1595 instantiation that matches an instance against the most general
  1596 declaration given in the signature.  For example, with the declaration
  1597 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1598 as c(nat).  Overloading is essentially simultaneous structural
  1599 recursion over such type arguments.  Incomplete specification patterns
  1600 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1601 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1602 Command 'print_theory' outputs the normalized system of recursive
  1603 equations, see section "definitions".
  1604 
  1605 * Configuration options are maintained within the theory or proof
  1606 context (with name and type bool/int/string), providing a very simple
  1607 interface to a poor-man's version of general context data.  Tools may
  1608 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1609 these values using Config.get etc.  Users may change options via an
  1610 associated attribute of the same name.  This form of context
  1611 declaration works particularly well with commands 'declare' or
  1612 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1613 very easy to avoid global references, which would not observe Isar
  1614 toplevel undo/redo and fail to work with multithreading.
  1615 
  1616 Various global ML references of Pure and HOL have been turned into
  1617 configuration options:
  1618 
  1619   Unify.search_bound		unify_search_bound
  1620   Unify.trace_bound		unify_trace_bound
  1621   Unify.trace_simp		unify_trace_simp
  1622   Unify.trace_types		unify_trace_types
  1623   Simplifier.simp_depth_limit	simp_depth_limit
  1624   Blast.depth_limit		blast_depth_limit
  1625   DatatypeProp.dtK		datatype_distinctness_limit
  1626   fast_arith_neq_limit  	fast_arith_neq_limit
  1627   fast_arith_split_limit	fast_arith_split_limit
  1628 
  1629 * Named collections of theorems may be easily installed as context
  1630 data using the functor NamedThmsFun (see also
  1631 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1632 attributes; there is also a toplevel print command.  This facility is
  1633 just a common case of general context data, which is the preferred way
  1634 for anything more complex than just a list of facts in canonical
  1635 order.
  1636 
  1637 * Isar: command 'declaration' augments a local theory by generic
  1638 declaration functions written in ML.  This enables arbitrary content
  1639 being added to the context, depending on a morphism that tells the
  1640 difference of the original declaration context wrt. the application
  1641 context encountered later on.
  1642 
  1643 * Isar: proper interfaces for simplification procedures.  Command
  1644 'simproc_setup' declares named simprocs (with match patterns, and body
  1645 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1646 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1647 
  1648 * Isar: an extra pair of brackets around attribute declarations
  1649 abbreviates a theorem reference involving an internal dummy fact,
  1650 which will be ignored later --- only the effect of the attribute on
  1651 the background context will persist.  This form of in-place
  1652 declarations is particularly useful with commands like 'declare' and
  1653 'using', for example ``have A using [[simproc a]] by simp''.
  1654 
  1655 * Isar: method "assumption" (and implicit closing of subproofs) now
  1656 takes simple non-atomic goal assumptions into account: after applying
  1657 an assumption as a rule the resulting subgoals are solved by atomic
  1658 assumption steps.  This is particularly useful to finish 'obtain'
  1659 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1660 without referring to the original premise "!!x. P x ==> thesis" in the
  1661 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1662 more permissive.
  1663 
  1664 * Isar: implicit use of prems from the Isar proof context is
  1665 considered a legacy feature.  Common applications like ``have A .''
  1666 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1667 referencing facts explicitly here improves readability and
  1668 maintainability of proof texts.
  1669 
  1670 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1671 the obtained context from the course of reasoning!  For example:
  1672 
  1673   assume "EX x y. A x & B y"   -- "any previous fact"
  1674   then guess x and y by clarify
  1675 
  1676 This technique is potentially adventurous, depending on the facts and
  1677 proof tools being involved here.
  1678 
  1679 * Isar: known facts from the proof context may be specified as literal
  1680 propositions, using ASCII back-quote syntax.  This works wherever
  1681 named facts used to be allowed so far, in proof commands, proof
  1682 methods, attributes etc.  Literal facts are retrieved from the context
  1683 according to unification of type and term parameters.  For example,
  1684 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1685 theorems in the current context, then these are valid literal facts:
  1686 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1687 
  1688 There is also a proof method "fact" which does the same composition
  1689 for explicit goal states, e.g. the following proof texts coincide with
  1690 certain special cases of literal facts:
  1691 
  1692   have "A" by fact                 ==  note `A`
  1693   have "A ==> B" by fact           ==  note `A ==> B`
  1694   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1695   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1696 
  1697 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1698 outer syntax.  Thus symbolic identifiers may be used without
  1699 additional white space in declarations like this: ``assume *: A''.
  1700 
  1701 * Isar: 'print_facts' prints all local facts of the current context,
  1702 both named and unnamed ones.
  1703 
  1704 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1705 
  1706   def x == "t" and y == "u"
  1707 
  1708 * Isar: added command 'unfolding', which is structurally similar to
  1709 'using', but affects both the goal state and facts by unfolding given
  1710 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1711 'unfolded' attribute may be replaced by first-class proof text.
  1712 
  1713 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1714 and command 'unfolding' now all support object-level equalities
  1715 (potentially conditional).  The underlying notion of rewrite rule is
  1716 analogous to the 'rule_format' attribute, but *not* that of the
  1717 Simplifier (which is usually more generous).
  1718 
  1719 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1720 premises of a theorem by n. Useful in conjunction with drule.
  1721 
  1722 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1723 method expression within a sandbox consisting of the first N
  1724 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1725 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1726 simplifies all new goals that emerge from applying rule foo to the
  1727 originally first one.
  1728 
  1729 * Isar: schematic goals are no longer restricted to higher-order
  1730 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1731 expected.
  1732 
  1733 * Isar: the conclusion of a long theorem statement is now either
  1734 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1735 (essentially a disjunction of cases with local parameters and
  1736 assumptions).  The latter allows to express general elimination rules
  1737 adequately; in this notation common elimination rules look like this:
  1738 
  1739   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1740     assumes "EX x. P x"
  1741     obtains x where "P x"
  1742 
  1743   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1744     assumes "A & B"
  1745     obtains A and B
  1746 
  1747   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1748     assumes "A | B"
  1749     obtains
  1750       A
  1751     | B
  1752 
  1753 The subsequent classical rules even refer to the formal "thesis"
  1754 explicitly:
  1755 
  1756   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1757     obtains "~ thesis"
  1758 
  1759   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1760     obtains "thesis ==> something"
  1761 
  1762 The actual proof of an 'obtains' statement is analogous to that of the
  1763 Isar proof element 'obtain', only that there may be several cases.
  1764 Optional case names may be specified in parentheses; these will be
  1765 available both in the present proof and as annotations in the
  1766 resulting rule, for later use with the 'cases' method (cf. attribute
  1767 case_names).
  1768 
  1769 * Isar: the assumptions of a long theorem statement are available as
  1770 "assms" fact in the proof context.  This is more appropriate than the
  1771 (historical) "prems", which refers to all assumptions of the current
  1772 context, including those from the target locale, proof body etc.
  1773 
  1774 * Isar: 'print_statement' prints theorems from the current theory or
  1775 proof context in long statement form, according to the syntax of a
  1776 top-level lemma.
  1777 
  1778 * Isar: 'obtain' takes an optional case name for the local context
  1779 introduction rule (default "that").
  1780 
  1781 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1782 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1783 to occur.
  1784 
  1785 * Pure: syntax "CONST name" produces a fully internalized constant
  1786 according to the current context.  This is particularly useful for
  1787 syntax translations that should refer to internal constant
  1788 representations independently of name spaces.
  1789 
  1790 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1791 instead of "FOO ". This allows multiple binder declarations to coexist
  1792 in the same context.  INCOMPATIBILITY.
  1793 
  1794 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1795 primitive that also works in a locale context (both for constants and
  1796 fixed variables). Type declaration and internal syntactic representation
  1797 of given constants retrieved from the context. Likewise, the
  1798 'no_notation' command allows to remove given syntax annotations from the
  1799 current context.
  1800 
  1801 * Isar/locales: new derived specification elements 'axiomatization',
  1802 'definition', 'abbreviation', which support type-inference, admit
  1803 object-level specifications (equality, equivalence).  See also the
  1804 isar-ref manual.  Examples:
  1805 
  1806   axiomatization
  1807     eq  (infix "===" 50) where
  1808     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1809 
  1810   definition "f x y = x + y + 1"
  1811   definition g where "g x = f x x"
  1812 
  1813   abbreviation
  1814     neq  (infix "=!=" 50) where
  1815     "x =!= y == ~ (x === y)"
  1816 
  1817 These specifications may be also used in a locale context.  Then the
  1818 constants being introduced depend on certain fixed parameters, and the
  1819 constant name is qualified by the locale base name.  An internal
  1820 abbreviation takes care for convenient input and output, making the
  1821 parameters implicit and using the original short name.  See also
  1822 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1823 entities from a monomorphic theory.
  1824 
  1825 Presently, abbreviations are only available 'in' a target locale, but
  1826 not inherited by general import expressions.  Also note that
  1827 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1828 'translations' in common applications.  The "no_abbrevs" print mode
  1829 prevents folding of abbreviations in term output.
  1830 
  1831 Concrete syntax is attached to specified constants in internal form,
  1832 independently of name spaces.  The parse tree representation is
  1833 slightly different -- use 'notation' instead of raw 'syntax', and
  1834 'translations' with explicit "CONST" markup to accommodate this.
  1835 
  1836 * Pure/Isar: unified syntax for new-style specification mechanisms
  1837 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1838 full type inference and dummy patterns ("_").  For example:
  1839 
  1840   definition "K x _ = x"
  1841 
  1842   inductive conj for A B
  1843   where "A ==> B ==> conj A B"
  1844 
  1845 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1846 the current context.  Print mode "no_abbrevs" prevents inversion of
  1847 abbreviations on output.
  1848 
  1849 * Isar/locales: improved parameter handling: use of locales "var" and
  1850 "struct" no longer necessary; - parameter renamings are no longer
  1851 required to be injective.  For example, this allows to define
  1852 endomorphisms as locale endom = homom mult mult h.
  1853 
  1854 * Isar/locales: changed the way locales with predicates are defined.
  1855 Instead of accumulating the specification, the imported expression is
  1856 now an interpretation.  INCOMPATIBILITY: different normal form of
  1857 locale expressions.  In particular, in interpretations of locales with
  1858 predicates, goals repesenting already interpreted fragments are not
  1859 removed automatically.  Use methods `intro_locales' and
  1860 `unfold_locales'; see below.
  1861 
  1862 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1863 provide backward reasoning on locales predicates.  The methods are
  1864 aware of interpretations and discharge corresponding goals.
  1865 `intro_locales' is less aggressive then `unfold_locales' and does not
  1866 unfold predicates to assumptions.
  1867 
  1868 * Isar/locales: the order in which locale fragments are accumulated
  1869 has changed.  This enables to override declarations from fragments due
  1870 to interpretations -- for example, unwanted simp rules.
  1871 
  1872 * Isar/locales: interpretation in theories and proof contexts has been
  1873 extended.  One may now specify (and prove) equations, which are
  1874 unfolded in interpreted theorems.  This is useful for replacing
  1875 defined concepts (constants depending on locale parameters) by
  1876 concepts already existing in the target context.  Example:
  1877 
  1878   interpretation partial_order ["op <= :: [int, int] => bool"]
  1879     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1880 
  1881 Typically, the constant `partial_order.less' is created by a
  1882 definition specification element in the context of locale
  1883 partial_order.
  1884 
  1885 * Method "induct": improved internal context management to support
  1886 local fixes and defines on-the-fly. Thus explicit meta-level
  1887 connectives !!  and ==> are rarely required anymore in inductive goals
  1888 (using object-logic connectives for this purpose has been long
  1889 obsolete anyway). Common proof patterns are explained in
  1890 src/HOL/Induct/Common_Patterns.thy, see also
  1891 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1892 examples.
  1893 
  1894 * Method "induct": improved handling of simultaneous goals. Instead of
  1895 introducing object-level conjunction, the statement is now split into
  1896 several conclusions, while the corresponding symbolic cases are nested
  1897 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1898 see src/HOL/Induct/Common_Patterns.thy, for example.
  1899 
  1900 * Method "induct": mutual induction rules are now specified as a list
  1901 of rule sharing the same induction cases. HOL packages usually provide
  1902 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1903 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1904 mutual induction rules differently, i.e. like this:
  1905 
  1906   (induct rule: foo_bar.inducts)
  1907   (induct set: foo bar)
  1908   (induct pred: foo bar)
  1909   (induct type: foo bar)
  1910 
  1911 The ML function ProjectRule.projections turns old-style rules into the
  1912 new format.
  1913 
  1914 * Method "coinduct": dual of induction, see
  1915 src/HOL/Library/Coinductive_List.thy for various examples.
  1916 
  1917 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1918 considered a legacy feature.
  1919 
  1920 * Attribute "symmetric" produces result with standardized schematic
  1921 variables (index 0).  Potential INCOMPATIBILITY.
  1922 
  1923 * Simplifier: by default the simplifier trace only shows top level
  1924 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1925 default. Thus there is less danger of being flooded by the trace. The
  1926 trace indicates where parts have been suppressed.
  1927   
  1928 * Provers/classical: removed obsolete classical version of elim_format
  1929 attribute; classical elim/dest rules are now treated uniformly when
  1930 manipulating the claset.
  1931 
  1932 * Provers/classical: stricter checks to ensure that supplied intro,
  1933 dest and elim rules are well-formed; dest and elim rules must have at
  1934 least one premise.
  1935 
  1936 * Provers/classical: attributes dest/elim/intro take an optional
  1937 weight argument for the rule (just as the Pure versions).  Weights are
  1938 ignored by automated tools, but determine the search order of single
  1939 rule steps.
  1940 
  1941 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1942 where the body does not mention the bound variable.  Note that dummy
  1943 patterns implicitly depend on their context of bounds, which makes
  1944 "{_. _}" match any set comprehension as expected.  Potential
  1945 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1946 constant "_idtdummy" in the binding position.
  1947 
  1948 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1949 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1950 for example "A -> B" => "Pi A (%_. B)".
  1951 
  1952 * Pure: 'class_deps' command visualizes the subclass relation, using
  1953 the graph browser tool.
  1954 
  1955 * Pure: 'print_theory' now suppresses certain internal declarations by
  1956 default; use '!' option for full details.
  1957 
  1958 
  1959 *** HOL ***
  1960 
  1961 * Method "metis" proves goals by applying the Metis general-purpose
  1962 resolution prover (see also http://gilith.com/software/metis/).
  1963 Examples are in the directory MetisExamples.  WARNING: the
  1964 Isabelle/HOL-Metis integration does not yet work properly with
  1965 multi-threading.
  1966   
  1967 * Command 'sledgehammer' invokes external automatic theorem provers as
  1968 background processes.  It generates calls to the "metis" method if
  1969 successful. These can be pasted into the proof.  Users do not have to
  1970 wait for the automatic provers to return.  WARNING: does not really
  1971 work with multi-threading.
  1972 
  1973 * New "auto_quickcheck" feature tests outermost goal statements for
  1974 potential counter-examples.  Controlled by ML references
  1975 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1976 5000 milliseconds).  Fails silently if statements is outside of
  1977 executable fragment, or any other codgenerator problem occurs.
  1978 
  1979 * New constant "undefined" with axiom "undefined x = undefined".
  1980 
  1981 * Added class "HOL.eq", allowing for code generation with polymorphic
  1982 equality.
  1983 
  1984 * Some renaming of class constants due to canonical name prefixing in
  1985 the new 'class' package:
  1986 
  1987     HOL.abs ~> HOL.abs_class.abs
  1988     HOL.divide ~> HOL.divide_class.divide
  1989     0 ~> HOL.zero_class.zero
  1990     1 ~> HOL.one_class.one
  1991     op + ~> HOL.plus_class.plus
  1992     op - ~> HOL.minus_class.minus
  1993     uminus ~> HOL.minus_class.uminus
  1994     op * ~> HOL.times_class.times
  1995     op < ~> HOL.ord_class.less
  1996     op <= > HOL.ord_class.less_eq
  1997     Nat.power ~> Power.power_class.power
  1998     Nat.size ~> Nat.size_class.size
  1999     Numeral.number_of ~> Numeral.number_class.number_of
  2000     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2001     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2002     Orderings.min ~> Orderings.ord_class.min
  2003     Orderings.max ~> Orderings.ord_class.max
  2004     Divides.op div ~> Divides.div_class.div
  2005     Divides.op mod ~> Divides.div_class.mod
  2006     Divides.op dvd ~> Divides.div_class.dvd
  2007 
  2008 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2009 
  2010 a) User-defined constants using any of the names "plus", "minus",
  2011 "times", "less" or "less_eq". The standard syntax translations for
  2012 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2013 names.
  2014 
  2015 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2016 INCOMPATIBILITY: use more specific names.
  2017 
  2018 c) Permutative equations (e.g. "a + b = b + a")
  2019 Since the change of names also changes the order of terms, permutative
  2020 rewrite rules may get applied in a different order. Experience shows
  2021 that this is rarely the case (only two adaptions in the whole Isabelle
  2022 distribution).  INCOMPATIBILITY: rewrite proofs
  2023 
  2024 d) ML code directly refering to constant names
  2025 This in general only affects hand-written proof tactics, simprocs and
  2026 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2027 Consider using @{const_name} antiquotation.
  2028 
  2029 * New class "default" with associated constant "default".
  2030 
  2031 * Function "sgn" is now overloaded and available on int, real, complex
  2032 (and other numeric types), using class "sgn".  Two possible defs of
  2033 sgn are given as equational assumptions in the classes sgn_if and
  2034 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2035 INCOMPATIBILITY.
  2036 
  2037 * Locale "partial_order" now unified with class "order" (cf. theory
  2038 Orderings), added parameter "less".  INCOMPATIBILITY.
  2039 
  2040 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2041 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2042 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2043 
  2044 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2045 changed order of proof goals in instance proofs.
  2046 
  2047 * The transitivity reasoner for partial and linear orders is set up
  2048 for classes "order" and "linorder".  Instances of the reasoner are available
  2049 in all contexts importing or interpreting the corresponding locales.
  2050 Method "order" invokes the reasoner separately; the reasoner
  2051 is also integrated with the Simplifier as a solver.  Diagnostic
  2052 command 'print_orders' shows the available instances of the reasoner
  2053 in the current context.
  2054 
  2055 * Localized monotonicity predicate in theory "Orderings"; integrated
  2056 lemmas max_of_mono and min_of_mono with this predicate.
  2057 INCOMPATIBILITY.
  2058 
  2059 * Formulation of theorem "dense" changed slightly due to integration
  2060 with new class dense_linear_order.
  2061 
  2062 * Uniform lattice theory development in HOL.
  2063 
  2064     constants "meet" and "join" now named "inf" and "sup"
  2065     constant "Meet" now named "Inf"
  2066 
  2067     classes "meet_semilorder" and "join_semilorder" now named
  2068       "lower_semilattice" and "upper_semilattice"
  2069     class "lorder" now named "lattice"
  2070     class "comp_lat" now named "complete_lattice"
  2071 
  2072     Instantiation of lattice classes allows explicit definitions
  2073     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2074 
  2075   INCOMPATIBILITY.  Theorem renames:
  2076 
  2077     meet_left_le            ~> inf_le1
  2078     meet_right_le           ~> inf_le2
  2079     join_left_le            ~> sup_ge1
  2080     join_right_le           ~> sup_ge2
  2081     meet_join_le            ~> inf_sup_ord
  2082     le_meetI                ~> le_infI
  2083     join_leI                ~> le_supI
  2084     le_meet                 ~> le_inf_iff
  2085     le_join                 ~> ge_sup_conv
  2086     meet_idempotent         ~> inf_idem
  2087     join_idempotent         ~> sup_idem
  2088     meet_comm               ~> inf_commute
  2089     join_comm               ~> sup_commute
  2090     meet_leI1               ~> le_infI1
  2091     meet_leI2               ~> le_infI2
  2092     le_joinI1               ~> le_supI1
  2093     le_joinI2               ~> le_supI2
  2094     meet_assoc              ~> inf_assoc
  2095     join_assoc              ~> sup_assoc
  2096     meet_left_comm          ~> inf_left_commute
  2097     meet_left_idempotent    ~> inf_left_idem
  2098     join_left_comm          ~> sup_left_commute
  2099     join_left_idempotent    ~> sup_left_idem
  2100     meet_aci                ~> inf_aci
  2101     join_aci                ~> sup_aci
  2102     le_def_meet             ~> le_iff_inf
  2103     le_def_join             ~> le_iff_sup
  2104     join_absorp2            ~> sup_absorb2
  2105     join_absorp1            ~> sup_absorb1
  2106     meet_absorp1            ~> inf_absorb1
  2107     meet_absorp2            ~> inf_absorb2
  2108     meet_join_absorp        ~> inf_sup_absorb
  2109     join_meet_absorp        ~> sup_inf_absorb
  2110     distrib_join_le         ~> distrib_sup_le
  2111     distrib_meet_le         ~> distrib_inf_le
  2112 
  2113     add_meet_distrib_left   ~> add_inf_distrib_left
  2114     add_join_distrib_left   ~> add_sup_distrib_left
  2115     is_join_neg_meet        ~> is_join_neg_inf
  2116     is_meet_neg_join        ~> is_meet_neg_sup
  2117     add_meet_distrib_right  ~> add_inf_distrib_right
  2118     add_join_distrib_right  ~> add_sup_distrib_right
  2119     add_meet_join_distribs  ~> add_sup_inf_distribs
  2120     join_eq_neg_meet        ~> sup_eq_neg_inf
  2121     meet_eq_neg_join        ~> inf_eq_neg_sup
  2122     add_eq_meet_join        ~> add_eq_inf_sup
  2123     meet_0_imp_0            ~> inf_0_imp_0
  2124     join_0_imp_0            ~> sup_0_imp_0
  2125     meet_0_eq_0             ~> inf_0_eq_0
  2126     join_0_eq_0             ~> sup_0_eq_0
  2127     neg_meet_eq_join        ~> neg_inf_eq_sup
  2128     neg_join_eq_meet        ~> neg_sup_eq_inf
  2129     join_eq_if              ~> sup_eq_if
  2130 
  2131     mono_meet               ~> mono_inf
  2132     mono_join               ~> mono_sup
  2133     meet_bool_eq            ~> inf_bool_eq
  2134     join_bool_eq            ~> sup_bool_eq
  2135     meet_fun_eq             ~> inf_fun_eq
  2136     join_fun_eq             ~> sup_fun_eq
  2137     meet_set_eq             ~> inf_set_eq
  2138     join_set_eq             ~> sup_set_eq
  2139     meet1_iff               ~> inf1_iff
  2140     meet2_iff               ~> inf2_iff
  2141     meet1I                  ~> inf1I
  2142     meet2I                  ~> inf2I
  2143     meet1D1                 ~> inf1D1
  2144     meet2D1                 ~> inf2D1
  2145     meet1D2                 ~> inf1D2
  2146     meet2D2                 ~> inf2D2
  2147     meet1E                  ~> inf1E
  2148     meet2E                  ~> inf2E
  2149     join1_iff               ~> sup1_iff
  2150     join2_iff               ~> sup2_iff
  2151     join1I1                 ~> sup1I1
  2152     join2I1                 ~> sup2I1
  2153     join1I1                 ~> sup1I1
  2154     join2I2                 ~> sup1I2
  2155     join1CI                 ~> sup1CI
  2156     join2CI                 ~> sup2CI
  2157     join1E                  ~> sup1E
  2158     join2E                  ~> sup2E
  2159 
  2160     is_meet_Meet            ~> is_meet_Inf
  2161     Meet_bool_def           ~> Inf_bool_def
  2162     Meet_fun_def            ~> Inf_fun_def
  2163     Meet_greatest           ~> Inf_greatest
  2164     Meet_lower              ~> Inf_lower
  2165     Meet_set_def            ~> Inf_set_def
  2166 
  2167     Sup_def                 ~> Sup_Inf
  2168     Sup_bool_eq             ~> Sup_bool_def
  2169     Sup_fun_eq              ~> Sup_fun_def
  2170     Sup_set_eq              ~> Sup_set_def
  2171 
  2172     listsp_meetI            ~> listsp_infI
  2173     listsp_meet_eq          ~> listsp_inf_eq
  2174 
  2175     meet_min                ~> inf_min
  2176     join_max                ~> sup_max
  2177 
  2178 * Added syntactic class "size"; overloaded constant "size" now has
  2179 type "'a::size ==> bool"
  2180 
  2181 * Internal reorganisation of `size' of datatypes: size theorems
  2182 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2183 simplification rules by default!); theorems "prod.size" now named
  2184 "*.size".
  2185 
  2186 * Class "div" now inherits from class "times" rather than "type".
  2187 INCOMPATIBILITY.
  2188 
  2189 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2190 Linorder etc.  have disappeared; operations defined in terms of
  2191 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2192 
  2193 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2194 
  2195 * HOL-Word: New extensive library and type for generic, fixed size
  2196 machine words, with arithemtic, bit-wise, shifting and rotating
  2197 operations, reflection into int, nat, and bool lists, automation for
  2198 linear arithmetic (by automatic reflection into nat or int), including
  2199 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2200 arithmetic type classes, supporting automatic simplification of
  2201 numerals on all operations.
  2202 
  2203 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2204 
  2205 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2206 
  2207 * Code generator library theories:
  2208   - Code_Integer represents HOL integers by big integer literals in target
  2209     languages.
  2210   - Code_Char represents HOL characters by character literals in target
  2211     languages.
  2212   - Code_Char_chr like Code_Char, but also offers treatment of character
  2213     codes; includes Code_Integer.
  2214   - Executable_Set allows to generate code for finite sets using lists.
  2215   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2216     denominator).
  2217   - Executable_Real implements a subset of real numbers, namly those
  2218     representable by rational numbers.
  2219   - Efficient_Nat implements natural numbers by integers, which in general will
  2220     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2221     includes Code_Integer.
  2222   - Code_Index provides an additional datatype index which is mapped to
  2223     target-language built-in integers.
  2224   - Code_Message provides an additional datatype message_string which is isomorphic to
  2225     strings; messages are mapped to target-language strings.
  2226 
  2227 * New package for inductive predicates
  2228 
  2229   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2230 
  2231     inductive
  2232       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2233       for z_1 :: U_1 and ... and z_n :: U_m
  2234     where
  2235       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2236     | ...
  2237 
  2238   with full support for type-inference, rather than
  2239 
  2240     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2241 
  2242     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2243     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2244 
  2245     inductive "s z_1 ... z_m"
  2246     intros
  2247       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2248       ...
  2249 
  2250   For backward compatibility, there is a wrapper allowing inductive
  2251   sets to be defined with the new package via
  2252 
  2253     inductive_set
  2254       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2255       for z_1 :: U_1 and ... and z_n :: U_m
  2256     where
  2257       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2258     | ...
  2259 
  2260   or
  2261 
  2262     inductive_set
  2263       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2264       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2265       for z_1 :: U_1 and ... and z_n :: U_m
  2266     where
  2267       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2268     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2269     | ...
  2270 
  2271   if the additional syntax "p ..." is required.
  2272 
  2273   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2274   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2275 
  2276   INCOMPATIBILITIES:
  2277 
  2278   - Since declaration and definition of inductive sets or predicates
  2279     is no longer separated, abbreviations involving the newly
  2280     introduced sets or predicates must be specified together with the
  2281     introduction rules after the 'where' keyword (see above), rather
  2282     than before the actual inductive definition.
  2283 
  2284   - The variables in induction and elimination rules are now
  2285     quantified in the order of their occurrence in the introduction
  2286     rules, rather than in alphabetical order. Since this may break
  2287     some proofs, these proofs either have to be repaired, e.g. by
  2288     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2289     statements of the form
  2290 
  2291       case (rule_i a_i_1 ... a_i_{k_i})
  2292 
  2293     or the old order of quantification has to be restored by explicitly adding
  2294     meta-level quantifiers in the introduction rules, i.e.
  2295 
  2296       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2297 
  2298   - The format of the elimination rules is now
  2299 
  2300       p z_1 ... z_m x_1 ... x_n ==>
  2301         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2302         ==> ... ==> P
  2303 
  2304     for predicates and
  2305 
  2306       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2307         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2308         ==> ... ==> P
  2309 
  2310     for sets rather than
  2311 
  2312       x : s z_1 ... z_m ==>
  2313         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2314         ==> ... ==> P
  2315 
  2316     This may require terms in goals to be expanded to n-tuples
  2317     (e.g. using case_tac or simplification with the split_paired_all
  2318     rule) before the above elimination rule is applicable.
  2319 
  2320   - The elimination or case analysis rules for (mutually) inductive
  2321     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2322     list of rules "p_1_..._p_k.elims" is no longer available.
  2323 
  2324 * New package "function"/"fun" for general recursive functions,
  2325 supporting mutual and nested recursion, definitions in local contexts,
  2326 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2327 for small examples, and the separate tutorial on the function
  2328 package. The old recdef "package" is still available as before, but
  2329 users are encouraged to use the new package.
  2330 
  2331 * Method "lexicographic_order" automatically synthesizes termination
  2332 relations as lexicographic combinations of size measures. 
  2333 
  2334 * Case-expressions allow arbitrary constructor-patterns (including
  2335 "_") and take their order into account, like in functional
  2336 programming.  Internally, this is translated into nested
  2337 case-expressions; missing cases are added and mapped to the predefined
  2338 constant "undefined". In complicated cases printing may no longer show
  2339 the original input but the internal form. Lambda-abstractions allow
  2340 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2341 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2342 variable.
  2343 
  2344 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2345 is an abbreviation for "of_nat :: nat => int". The simplification
  2346 rules for "of_nat" have been changed to work like "int" did
  2347 previously.  Potential INCOMPATIBILITY:
  2348   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2349   - of_nat_diff and of_nat_mult are no longer default simp rules
  2350 
  2351 * Method "algebra" solves polynomial equations over (semi)rings using
  2352 Groebner bases. The (semi)ring structure is defined by locales and the
  2353 tool setup depends on that generic context. Installing the method for
  2354 a specific type involves instantiating the locale and possibly adding
  2355 declarations for computation on the coefficients.  The method is
  2356 already instantiated for natural numbers and for the axiomatic class
  2357 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2358 CALCULEMUS 2007 for the general principles underlying this
  2359 architecture of context-aware proof-tools.
  2360 
  2361 * Method "ferrack" implements quantifier elimination over
  2362 special-purpose dense linear orders using locales (analogous to
  2363 "algebra"). The method is already installed for class
  2364 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2365 rat, etc.
  2366 
  2367 * Former constant "List.op @" now named "List.append".  Use ML
  2368 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2369 circumvent possible incompatibilities when working on ML level.
  2370 
  2371 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2372 
  2373 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2374 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2375 
  2376 * New syntax for Haskell-like list comprehension (input only), eg.
  2377 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2378 
  2379 * The special syntax for function "filter" has changed from [x :
  2380 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2381 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2382 
  2383 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2384 defined on nat only, as an abbreviation for [a..<Suc b]
  2385 INCOMPATIBILITY.
  2386 
  2387 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2388 
  2389 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2390 
  2391 * New lemma collection field_simps (an extension of ring_simps) for
  2392 manipulating (in)equations involving division. Multiplies with all
  2393 denominators that can be proved to be non-zero (in equations) or
  2394 positive/negative (in inequations).
  2395 
  2396 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2397 have been improved and renamed to ring_simps, group_simps and
  2398 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2399 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2400 
  2401 * Theory Library/Commutative_Ring: switched from recdef to function
  2402 package; constants add, mul, pow now curried.  Infix syntax for
  2403 algebraic operations.
  2404 
  2405 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2406 INCOMPATIBILITY.
  2407 
  2408 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2409 INCOMPATIBILITY.
  2410 
  2411 * HOL/records: generalised field-update to take a function on the
  2412 field rather than the new value: r(|A := x|) is translated to A_update
  2413 (K x) r The K-combinator that is internally used is called K_record.
  2414 INCOMPATIBILITY: Usage of the plain update functions has to be
  2415 adapted.
  2416  
  2417 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2418 * x = 0, which are required for a semiring.  Richer structures do not
  2419 inherit from semiring_0 anymore, because this property is a theorem
  2420 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2421 there is more to prove, but this is mostly trivial.
  2422 
  2423 * Class "recpower" is generalized to arbitrary monoids, not just
  2424 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2425 commutativity or semiring properties additionally.
  2426 
  2427 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2428 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2429 better use 'abbreviation'.
  2430 
  2431 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2432 
  2433 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2434 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2435 significant changes for setting up numeral syntax for types:
  2436   - New constants Numeral.pred and Numeral.succ instead
  2437       of former Numeral.bin_pred and Numeral.bin_succ.
  2438   - Use integer operations instead of bin_add, bin_mult and so on.
  2439   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2440   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2441 
  2442 See src/HOL/Integ/IntArith.thy for an example setup.
  2443 
  2444 * Command 'normal_form' computes the normal form of a term that may
  2445 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2446 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2447 heavy-duty computations because the functions are compiled to ML
  2448 first.  Correspondingly, a method "normalization" is provided.  See
  2449 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2450 
  2451 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2452 25 like -->); output depends on the "iff" print_mode, the default is
  2453 "A = B" (with priority 50).
  2454 
  2455 * Relations less (<) and less_eq (<=) are also available on type bool.
  2456 Modified syntax to disallow nesting without explicit parentheses,
  2457 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2458 INCOMPATIBILITY.
  2459 
  2460 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2461 
  2462 * Relation composition operator "op O" now has precedence 75 and binds
  2463 stronger than union and intersection. INCOMPATIBILITY.
  2464 
  2465 * The old set interval syntax "{m..n(}" (and relatives) has been
  2466 removed.  Use "{m..<n}" (and relatives) instead.
  2467 
  2468 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2469 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2470 ``declare [[simproc del: neq]]''.
  2471 
  2472 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2473 True/False.
  2474 
  2475 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2476 
  2477 * Theorem setsum_mult renamed to setsum_right_distrib.
  2478 
  2479 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2480 ``rule'' method.
  2481 
  2482 * Reimplemented methods "sat" and "satx", with several improvements:
  2483 goals no longer need to be stated as "<prems> ==> False", equivalences
  2484 (i.e. "=" on type bool) are handled, variable names of the form
  2485 "lit_<n>" are no longer reserved, significant speedup.
  2486 
  2487 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2488 zChaff is still supported as well.
  2489 
  2490 * 'inductive' and 'datatype': provide projections of mutual rules,
  2491 bundled as foo_bar.inducts;
  2492 
  2493 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2494 Library.
  2495 
  2496 * Library: moved theory Accessible_Part to main HOL.
  2497 
  2498 * Library: added theory Coinductive_List of potentially infinite lists
  2499 as greatest fixed-point.
  2500 
  2501 * Library: added theory AssocList which implements (finite) maps as
  2502 association lists.
  2503 
  2504 * Method "evaluation" solves goals (i.e. a boolean expression)
  2505 efficiently by compiling it to ML.  The goal is "proved" (via an
  2506 oracle) if it evaluates to True.
  2507 
  2508 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2509 also when invoked by the simplifier.  This results in the Simplifier
  2510 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2511 Configuration option fast_arith_split_limit=0 recovers the old
  2512 behavior.
  2513 
  2514 * Support for hex (0x20) and binary (0b1001) numerals.
  2515 
  2516 * New method: reify eqs (t), where eqs are equations for an
  2517 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2518 parameter, computes a term s::'b and a list xs::'a list and proves the
  2519 theorem I xs s = t. This is also known as reification or quoting. The
  2520 resulting theorem is applied to the subgoal to substitute t with I xs
  2521 s.  If t is omitted, the subgoal itself is reified.
  2522 
  2523 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2524 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2525 where f is supposed to be a computable function (in the sense of code
  2526 generattion). The method uses reify to compute s and xs as above then
  2527 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2528 r and finally gets the theorem t = r, which is again applied to the
  2529 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2530 
  2531 * Reflection: Automatic reification now handels binding, an example is
  2532 available in src/HOL/ex/ReflectionEx.thy
  2533 
  2534 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2535 command 'statespace' that is similar to 'record', but introduces an
  2536 abstract specification based on the locale infrastructure instead of
  2537 HOL types.  This leads to extra flexibility in composing state spaces,
  2538 in particular multiple inheritance and renaming of components.
  2539 
  2540 
  2541 *** HOL-Complex ***
  2542 
  2543 * Hyperreal: Functions root and sqrt are now defined on negative real
  2544 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2545 Nonnegativity side conditions have been removed from many lemmas, so
  2546 that more subgoals may now be solved by simplification; potential
  2547 INCOMPATIBILITY.
  2548 
  2549 * Real: new type classes formalize real normed vector spaces and
  2550 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2551 and norm :: 'a => real.
  2552 
  2553 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2554 reals into other types. The overloaded constant Reals :: 'a set is now
  2555 defined as range of_real; potential INCOMPATIBILITY.
  2556 
  2557 * Real: proper support for ML code generation, including 'quickcheck'.
  2558 Reals are implemented as arbitrary precision rationals.
  2559 
  2560 * Hyperreal: Several constants that previously worked only for the
  2561 reals have been generalized, so they now work over arbitrary vector
  2562 spaces. Type annotations may need to be added in some cases; potential
  2563 INCOMPATIBILITY.
  2564 
  2565   Infinitesimal  :: ('a::real_normed_vector) star set
  2566   HFinite        :: ('a::real_normed_vector) star set
  2567   HInfinite      :: ('a::real_normed_vector) star set
  2568   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2569   monad          :: ('a::real_normed_vector) star => 'a star set
  2570   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2571   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2572   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2573   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2574   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2575   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2576   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2577   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2578   sgn            :: 'a::real_normed_vector => 'a
  2579   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2580 
  2581 * Complex: Some complex-specific constants are now abbreviations for
  2582 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2583 hnorm.  Other constants have been entirely removed in favor of the
  2584 polymorphic versions (INCOMPATIBILITY):
  2585 
  2586   approx        <-- capprox
  2587   HFinite       <-- CFinite
  2588   HInfinite     <-- CInfinite
  2589   Infinitesimal <-- CInfinitesimal
  2590   monad         <-- cmonad
  2591   galaxy        <-- cgalaxy
  2592   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2593   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2594   (ns)deriv     <-- (ns)cderiv
  2595 
  2596 
  2597 *** HOL-Algebra ***
  2598 
  2599 * Formalisation of ideals and the quotient construction over rings.
  2600 
  2601 * Order and lattice theory no longer based on records.
  2602 INCOMPATIBILITY.
  2603 
  2604 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2605 greatest_closed.  INCOMPATIBILITY.
  2606 
  2607 * Method algebra is now set up via an attribute.  For examples see
  2608 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2609 of algebraic structures.
  2610 
  2611 * Renamed theory CRing to Ring.
  2612 
  2613 
  2614 *** HOL-Nominal ***
  2615 
  2616 * Substantial, yet incomplete support for nominal datatypes (binding
  2617 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2618 src/HOL/Nominal/Examples.  Prospective users should consult
  2619 http://isabelle.in.tum.de/nominal/
  2620 
  2621 
  2622 *** ML ***
  2623 
  2624 * ML basics: just one true type int, which coincides with IntInf.int
  2625 (even on SML/NJ).
  2626 
  2627 * ML within Isar: antiquotations allow to embed statically-checked
  2628 formal entities in the source, referring to the context available at
  2629 compile-time.  For example:
  2630 
  2631 ML {* @{sort "{zero,one}"} *}
  2632 ML {* @{typ "'a => 'b"} *}
  2633 ML {* @{term "%x. x"} *}
  2634 ML {* @{prop "x == y"} *}
  2635 ML {* @{ctyp "'a => 'b"} *}
  2636 ML {* @{cterm "%x. x"} *}
  2637 ML {* @{cprop "x == y"} *}
  2638 ML {* @{thm asm_rl} *}
  2639 ML {* @{thms asm_rl} *}
  2640 ML {* @{type_name c} *}
  2641 ML {* @{type_syntax c} *}
  2642 ML {* @{const_name c} *}
  2643 ML {* @{const_syntax c} *}
  2644 ML {* @{context} *}
  2645 ML {* @{theory} *}
  2646 ML {* @{theory Pure} *}
  2647 ML {* @{theory_ref} *}
  2648 ML {* @{theory_ref Pure} *}
  2649 ML {* @{simpset} *}
  2650 ML {* @{claset} *}
  2651 ML {* @{clasimpset} *}
  2652 
  2653 The same works for sources being ``used'' within an Isar context.
  2654 
  2655 * ML in Isar: improved error reporting; extra verbosity with
  2656 ML_Context.trace enabled.
  2657 
  2658 * Pure/General/table.ML: the join operations now works via exceptions
  2659 DUP/SAME instead of type option. This is simpler in simple cases, and
  2660 admits slightly more efficient complex applications.
  2661 
  2662 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2663 use Context.generic instead of just theory.
  2664 
  2665 * Pure: datatype Context.generic joins theory/Proof.context and
  2666 provides some facilities for code that works in either kind of
  2667 context, notably GenericDataFun for uniform theory and proof data.
  2668 
  2669 * Pure: simplified internal attribute type, which is now always
  2670 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2671 local (Proof.context) attributes have been discontinued, while
  2672 minimizing code duplication. Thm.rule_attribute and
  2673 Thm.declaration_attribute build canonical attributes; see also structure
  2674 Context for further operations on Context.generic, notably
  2675 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2676 declarations and definitions.
  2677 
  2678 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2679 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2680 init only required for impure data. INCOMPATIBILITY: empty really need
  2681 to be empty (no dependencies on theory content!)
  2682 
  2683 * Pure/kernel: consts certification ignores sort constraints given in
  2684 signature declarations. (This information is not relevant to the
  2685 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2686 potential INCOMPATIBILITY.
  2687 
  2688 * Pure: axiomatic type classes are now purely definitional, with
  2689 explicit proofs of class axioms and super class relations performed
  2690 internally. See Pure/axclass.ML for the main internal interfaces --
  2691 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2692 AxClass.axiomatize_class/classrel/arity supersede
  2693 Sign.add_classes/classrel/arities.
  2694 
  2695 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2696 global/local versions on theory vs. Proof.context have been
  2697 discontinued; Attrib.syntax and Method.syntax have been adapted
  2698 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2699 attributes, methods, etc.
  2700 
  2701 * Pure: several functions of signature "... -> theory -> theory * ..."
  2702 have been reoriented to "... -> theory -> ... * theory" in order to
  2703 allow natural usage in combination with the ||>, ||>>, |-> and
  2704 fold_map combinators.
  2705 
  2706 * Pure: official theorem names (closed derivations) and additional
  2707 comments (tags) are now strictly separate.  Name hints -- which are
  2708 maintained as tags -- may be attached any time without affecting the
  2709 derivation.
  2710 
  2711 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2712 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2713 achieve the old behaviour.
  2714 
  2715 * Pure: the "Goal" constant is now called "prop", supporting a
  2716 slightly more general idea of ``protecting'' meta-level rule
  2717 statements.
  2718 
  2719 * Pure: Logic.(un)varify only works in a global context, which is now
  2720 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2721 Logic.legacy_(un)varify as temporary workaround.
  2722 
  2723 * Pure: structure Name provides scalable operations for generating
  2724 internal variable names, notably Name.variants etc.  This replaces
  2725 some popular functions from term.ML:
  2726 
  2727   Term.variant		->  Name.variant
  2728   Term.variantlist	->  Name.variant_list
  2729   Term.invent_names	->  Name.invent_list
  2730 
  2731 Note that low-level renaming rarely occurs in new code -- operations
  2732 from structure Variable are used instead (see below).
  2733 
  2734 * Pure: structure Variable provides fundamental operations for proper
  2735 treatment of fixed/schematic variables in a context.  For example,
  2736 Variable.import introduces fixes for schematics of given facts and
  2737 Variable.export reverses the effect (up to renaming) -- this replaces
  2738 various freeze_thaw operations.
  2739 
  2740 * Pure: structure Goal provides simple interfaces for
  2741 init/conclude/finish and tactical prove operations (replacing former
  2742 Tactic.prove).  Goal.prove is the canonical way to prove results
  2743 within a given context; Goal.prove_global is a degraded version for
  2744 theory level goals, including a global Drule.standard.  Note that
  2745 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2746 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2747 in a locale context).
  2748 
  2749 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2750 and type checking (Syntax.check_term etc.), with common combinations
  2751 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2752 which are considered legacy and await removal.
  2753 
  2754 * Pure/Syntax: generic interfaces for type unchecking
  2755 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2756 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2757 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2758 available for convenience, but refer to the very same operations using
  2759 a mere theory instead of a full context.
  2760 
  2761 * Isar: simplified treatment of user-level errors, using exception
  2762 ERROR of string uniformly.  Function error now merely raises ERROR,
  2763 without any side effect on output channels.  The Isar toplevel takes
  2764 care of proper display of ERROR exceptions.  ML code may use plain
  2765 handle/can/try; cat_error may be used to concatenate errors like this:
  2766 
  2767   ... handle ERROR msg => cat_error msg "..."
  2768 
  2769 Toplevel ML code (run directly or through the Isar toplevel) may be
  2770 embedded into the Isar toplevel with exception display/debug like
  2771 this:
  2772 
  2773   Isar.toplevel (fn () => ...)
  2774 
  2775 INCOMPATIBILITY, removed special transform_error facilities, removed
  2776 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2777 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2778 -- use plain ERROR instead.
  2779 
  2780 * Isar: theory setup now has type (theory -> theory), instead of a
  2781 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2782 
  2783 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2784 ProofContext.debug/verbose flags.
  2785 
  2786 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2787 theory before entering a proof state.  Transactions now always see a
  2788 quasi-functional intermediate checkpoint, both in interactive and
  2789 batch mode.
  2790 
  2791 * Isar: simplified interfaces for outer syntax.  Renamed
  2792 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2793 OuterSyntax.add_parsers -- this functionality is now included in
  2794 OuterSyntax.command etc.  INCOMPATIBILITY.
  2795 
  2796 * Simplifier: the simpset of a running simplification process now
  2797 contains a proof context (cf. Simplifier.the_context), which is the
  2798 very context that the initial simpset has been retrieved from (by
  2799 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2800 (solver, looper etc.) may depend on arbitrary proof data.
  2801 
  2802 * Simplifier.inherit_context inherits the proof context (plus the
  2803 local bounds) of the current simplification process; any simproc
  2804 etc. that calls the Simplifier recursively should do this!  Removed
  2805 former Simplifier.inherit_bounds, which is already included here --
  2806 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2807 specify an explicit context using Simplifier.context/theory_context.
  2808 
  2809 * Simplifier/Classical Reasoner: more abstract interfaces
  2810 change_simpset/claset for modifying the simpset/claset reference of a
  2811 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2812 INCOMPATIBILITY.
  2813 
  2814 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2815 "Trueprop" etc.
  2816 
  2817 
  2818 *** System ***
  2819 
  2820 * settings: the default heap location within ISABELLE_HOME_USER now
  2821 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2822 Isabelle installations.
  2823 
  2824 * isabelle-process: option -S (secure mode) disables some critical
  2825 operations, notably runtime compilation and evaluation of ML source
  2826 code.
  2827 
  2828 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2829 
  2830 * Support for parallel execution, using native multicore support of
  2831 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2832 independent theories, according to the given theory header
  2833 specifications. The maximum number of worker threads is specified via
  2834 usedir option -M or the "max-threads" setting in Proof General. A
  2835 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2836 to 6 on a 8-core machine.  User-code needs to observe certain
  2837 guidelines for thread-safe programming, see appendix A in the Isar
  2838 Implementation manual.
  2839 
  2840 
  2841 
  2842 New in Isabelle2005 (October 2005)
  2843 ----------------------------------
  2844 
  2845 *** General ***
  2846 
  2847 * Theory headers: the new header syntax for Isar theories is
  2848 
  2849   theory <name>
  2850   imports <theory1> ... <theoryN>
  2851   uses <file1> ... <fileM>
  2852   begin
  2853 
  2854 where the 'uses' part is optional.  The previous syntax
  2855 
  2856   theory <name> = <theory1> + ... + <theoryN>:
  2857 
  2858 will disappear in the next release.  Use isatool fixheaders to convert
  2859 existing theory files.  Note that there is no change in ancient
  2860 non-Isar theories now, but these will disappear soon.
  2861 
  2862 * Theory loader: parent theories can now also be referred to via
  2863 relative and absolute paths.
  2864 
  2865 * Command 'find_theorems' searches for a list of criteria instead of a
  2866 list of constants. Known criteria are: intro, elim, dest, name:string,
  2867 simp:term, and any term. Criteria can be preceded by '-' to select
  2868 theorems that do not match. Intro, elim, dest select theorems that
  2869 match the current goal, name:s selects theorems whose fully qualified
  2870 name contain s, and simp:term selects all simplification rules whose
  2871 lhs match term.  Any other term is interpreted as pattern and selects
  2872 all theorems matching the pattern. Available in ProofGeneral under
  2873 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2874 
  2875   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2876 
  2877 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2878 matching the current goal as introduction rule and not having "HOL."
  2879 in their name (i.e. not being defined in theory HOL).
  2880 
  2881 * Command 'thms_containing' has been discontinued in favour of
  2882 'find_theorems'; INCOMPATIBILITY.
  2883 
  2884 * Communication with Proof General is now 8bit clean, which means that
  2885 Unicode text in UTF-8 encoding may be used within theory texts (both
  2886 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2887 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2888 
  2889   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2890   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2891 
  2892 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2893 Classical Reasoner.  Typical big applications run around 2 times
  2894 faster.
  2895 
  2896 
  2897 *** Document preparation ***
  2898 
  2899 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2900 of raw sources.  Only those symbols that do not require additional
  2901 LaTeX packages (depending on comments in isabellesym.sty) are
  2902 displayed properly, everything else is left verbatim.  isatool display
  2903 and isatool print are used as front ends (these are subject to the
  2904 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2905 
  2906 * Command tags control specific markup of certain regions of text,
  2907 notably folding and hiding.  Predefined tags include "theory" (for
  2908 theory begin and end), "proof" for proof commands, and "ML" for
  2909 commands involving ML code; the additional tags "visible" and
  2910 "invisible" are unused by default.  Users may give explicit tag
  2911 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2912 interpretation of tags is determined by the LaTeX job during document
  2913 preparation: see option -V of isatool usedir, or options -n and -t of
  2914 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2915 \isadroptag.
  2916 
  2917 Several document versions may be produced at the same time via isatool
  2918 usedir (the generated index.html will link all of them).  Typical
  2919 specifications include ''-V document=theory,proof,ML'' to present
  2920 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2921 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2922 these parts without any formal replacement text.  The Isabelle site
  2923 default settings produce ''document'' and ''outline'' versions as
  2924 specified above.
  2925 
  2926 * Several new antiquotations:
  2927 
  2928   @{term_type term} prints a term with its type annotated;
  2929 
  2930   @{typeof term} prints the type of a term;
  2931 
  2932   @{const const} is the same as @{term const}, but checks that the
  2933   argument is a known logical constant;
  2934 
  2935   @{term_style style term} and @{thm_style style thm} print a term or
  2936   theorem applying a "style" to it
  2937 
  2938   @{ML text}
  2939 
  2940 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2941 definitions, equations, inequations etc., 'concl' printing only the
  2942 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2943 to print the specified premise.  TermStyle.add_style provides an ML
  2944 interface for introducing further styles.  See also the "LaTeX Sugar"
  2945 document practical applications.  The ML antiquotation prints
  2946 type-checked ML expressions verbatim.
  2947 
  2948 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2949 and 'text' support optional locale specification '(in loc)', which
  2950 specifies the default context for interpreting antiquotations.  For
  2951 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2952 
  2953 * Option 'locale=NAME' of antiquotations specifies an alternative
  2954 context interpreting the subsequent argument.  For example: @{thm
  2955 [locale=lattice] inf_assoc}.
  2956 
  2957 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2958 a proof context.
  2959 
  2960 * Proper output of antiquotations for theory commands involving a
  2961 proof context (such as 'locale' or 'theorem (in loc) ...').
  2962 
  2963 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2964 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2965 
  2966 * isatool usedir: new option -C (default true) controls whether option
  2967 -D should include a copy of the original document directory; -C false
  2968 prevents unwanted effects such as copying of administrative CVS data.
  2969 
  2970 
  2971 *** Pure ***
  2972 
  2973 * Considerably improved version of 'constdefs' command.  Now performs
  2974 automatic type-inference of declared constants; additional support for
  2975 local structure declarations (cf. locales and HOL records), see also
  2976 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2977 sequential dependencies of definitions within a single 'constdefs'
  2978 section; moreover, the declared name needs to be an identifier.  If
  2979 all fails, consider to fall back on 'consts' and 'defs' separately.
  2980 
  2981 * Improved indexed syntax and implicit structures.  First of all,
  2982 indexed syntax provides a notational device for subscripted
  2983 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2984 expressions.  Secondly, in a local context with structure
  2985 declarations, number indexes \<^sub>n or the empty index (default
  2986 number 1) refer to a certain fixed variable implicitly; option
  2987 show_structs controls printing of implicit structures.  Typical
  2988 applications of these concepts involve record types and locales.
  2989 
  2990 * New command 'no_syntax' removes grammar declarations (and
  2991 translations) resulting from the given syntax specification, which is
  2992 interpreted in the same manner as for the 'syntax' command.
  2993 
  2994 * 'Advanced' translation functions (parse_translation etc.) may depend
  2995 on the signature of the theory context being presently used for
  2996 parsing/printing, see also isar-ref manual.
  2997 
  2998 * Improved 'oracle' command provides a type-safe interface to turn an
  2999 ML expression of type theory -> T -> term into a primitive rule of
  3000 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3001 is already included here); see also FOL/ex/IffExample.thy;
  3002 INCOMPATIBILITY.
  3003 
  3004 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3005 before); "cI" is no longer bound, use "c.intro" instead.
  3006 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3007 axclasses vs. locales.
  3008 
  3009 * Improved internal renaming of symbolic identifiers -- attach primes
  3010 instead of base 26 numbers.
  3011 
  3012 * New flag show_question_marks controls printing of leading question
  3013 marks in schematic variable names.
  3014 
  3015 * In schematic variable names, *any* symbol following \<^isub> or
  3016 \<^isup> is now treated as part of the base name.  For example, the
  3017 following works without printing of awkward ".0" indexes:
  3018 
  3019   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3020     by simp
  3021 
  3022 * Inner syntax includes (*(*nested*) comments*).
  3023 
  3024 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3025 annotations as "(00...)".
  3026 
  3027 * Clear separation of logical types and nonterminals, where the latter
  3028 may only occur in 'syntax' specifications or type abbreviations.
  3029 Before that distinction was only partially implemented via type class
  3030 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3031 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3032 exotic syntax specifications may require further adaption
  3033 (e.g. Cube/Cube.thy).
  3034 
  3035 * Removed obsolete type class "logic", use the top sort {} instead.
  3036 Note that non-logical types should be declared as 'nonterminals'
  3037 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3038 specifications.
  3039 
  3040 * Attributes 'induct' and 'cases': type or set names may now be
  3041 locally fixed variables as well.
  3042 
  3043 * Simplifier: can now control the depth to which conditional rewriting
  3044 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3045 Limit.
  3046 
  3047 * Simplifier: simplification procedures may now take the current
  3048 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3049 interface), which is very useful for calling the Simplifier
  3050 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3051 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3052 low-level mk_simproc no longer applies Logic.varify internally, to
  3053 allow for use in a context of fixed variables.
  3054 
  3055 * thin_tac now works even if the assumption being deleted contains !!
  3056 or ==>.  More generally, erule now works even if the major premise of
  3057 the elimination rule contains !! or ==>.
  3058 
  3059 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3060 
  3061 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3062 from Pure, which contains all common declarations already.  Both
  3063 theories are defined via plain Isabelle/Isar .thy files.
  3064 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3065 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3066 use isatool fixcpure to adapt your theory and ML sources.
  3067 
  3068 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3069 selections of theorems in named facts via index ranges.
  3070 
  3071 * 'print_theorems': in theory mode, really print the difference
  3072 wrt. the last state (works for interactive theory development only),
  3073 in proof mode print all local facts (cf. 'print_facts');
  3074 
  3075 * 'hide': option '(open)' hides only base names.
  3076 
  3077 * More efficient treatment of intermediate checkpoints in interactive
  3078 theory development.
  3079 
  3080 * Code generator is now invoked via code_module (incremental code
  3081 generation) and code_library (modular code generation, ML structures
  3082 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3083 must be quoted when used as identifiers.
  3084 
  3085 * New 'value' command for reading, evaluating and printing terms using
  3086 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3087 quoted when used as identifier.
  3088 
  3089 
  3090 *** Locales ***
  3091 
  3092 * New commands for the interpretation of locale expressions in
  3093 theories (1), locales (2) and proof contexts (3).  These generate
  3094 proof obligations from the expression specification.  After the
  3095 obligations have been discharged, theorems of the expression are added
  3096 to the theory, target locale or proof context.  The synopsis of the
  3097 commands is a follows:
  3098 
  3099   (1) interpretation expr inst
  3100   (2) interpretation target < expr
  3101   (3) interpret expr inst
  3102 
  3103 Interpretation in theories and proof contexts require a parameter
  3104 instantiation of terms from the current context.  This is applied to
  3105 specifications and theorems of the interpreted expression.
  3106 Interpretation in locales only permits parameter renaming through the
  3107 locale expression.  Interpretation is smart in that interpretations
  3108 that are active already do not occur in proof obligations, neither are
  3109 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3110 inspect active interpretations of a particular locale.  For details,
  3111 see the Isar Reference manual.  Examples can be found in
  3112 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3113 
  3114 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3115 'interpret' instead.
  3116 
  3117 * New context element 'constrains' for adding type constraints to
  3118 parameters.
  3119 
  3120 * Context expressions: renaming of parameters with syntax
  3121 redeclaration.
  3122 
  3123 * Locale declaration: 'includes' disallowed.
  3124 
  3125 * Proper static binding of attribute syntax -- i.e. types / terms /
  3126 facts mentioned as arguments are always those of the locale definition
  3127 context, independently of the context of later invocations.  Moreover,
  3128 locale operations (renaming and type / term instantiation) are applied
  3129 to attribute arguments as expected.
  3130 
  3131 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3132 actual attributes; rare situations may require Attrib.attribute to
  3133 embed those attributes into Attrib.src that lack concrete syntax.
  3134 Attribute implementations need to cooperate properly with the static
  3135 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3136 Attrib.XXX_thm etc. already do the right thing without further
  3137 intervention.  Only unusual applications -- such as "where" or "of"
  3138 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3139 on the context and the facts involved -- may have to assign parsed
  3140 values to argument tokens explicitly.
  3141 
  3142 * Changed parameter management in theorem generation for long goal
  3143 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3144 theorem statement in rare situations.
  3145 
  3146 * Locale inspection command 'print_locale' omits notes elements.  Use
  3147 'print_locale!' to have them included in the output.
  3148 
  3149 
  3150 *** Provers ***
  3151 
  3152 * Provers/hypsubst.ML: improved version of the subst method, for
  3153 single-step rewriting: it now works in bound variable contexts. New is
  3154 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3155 rewrite a different subterm than the original subst method, which is
  3156 still available as 'simplesubst'.
  3157 
  3158 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3159 and quasi orders.
  3160 
  3161 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3162 reflexive-transitive closure of relations.
  3163 
  3164 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3165 limit (previously hard-coded with a value of 20) user-definable.
  3166 
  3167 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3168 is peformed already.  Object-logics merely need to finish their
  3169 initial simpset configuration as before.  INCOMPATIBILITY.
  3170 
  3171 
  3172 *** HOL ***
  3173 
  3174 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3175 
  3176   syntax (epsilon)
  3177     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3178 
  3179 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3180 and x-symbol; use option '-m epsilon' to get it actually printed.
  3181 Moreover, the mathematically important symbolic identifier \<epsilon>
  3182 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3183 
  3184 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3185 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3186 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3187 support corresponding Isar calculations.
  3188 
  3189 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3190 instead of ":".
  3191 
  3192 * theory SetInterval: changed the syntax for open intervals:
  3193 
  3194   Old       New
  3195   {..n(}    {..<n}
  3196   {)n..}    {n<..}
  3197   {m..n(}   {m..<n}
  3198   {)m..n}   {m<..n}
  3199   {)m..n(}  {m<..<n}
  3200 
  3201 The old syntax is still supported but will disappear in the next
  3202 release.  For conversion use the following Emacs search and replace
  3203 patterns (these are not perfect but work quite well):
  3204 
  3205   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3206   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3207 
  3208 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3209 equalities in commutative rings; method 'algebra' provides a generic
  3210 interface.
  3211 
  3212 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3213 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3214 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3215 be a tuple pattern.
  3216 
  3217 Some new syntax forms are available:
  3218 
  3219   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3220   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3221   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3222   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3223 
  3224 The latter form "\<Sum>x < k. e" used to be based on a separate
  3225 function "Summation", which has been discontinued.
  3226 
  3227 * theory Finite_Set: in structured induction proofs, the insert case
  3228 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3229 (insert F x)'.
  3230 
  3231 * The 'refute' command has been extended to support a much larger
  3232 fragment of HOL, including axiomatic type classes, constdefs and
  3233 typedefs, inductive datatypes and recursion.
  3234 
  3235 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3236 Requires zChaff with proof generation to be installed.  See
  3237 HOL/ex/SAT_Examples.thy for examples.
  3238 
  3239 * Datatype induction via method 'induct' now preserves the name of the
  3240 induction variable. For example, when proving P(xs::'a list) by
  3241 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3242 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3243 in unstructured proof scripts.
  3244 
  3245 * Reworked implementation of records.  Improved scalability for
  3246 records with many fields, avoiding performance problems for type
  3247 inference. Records are no longer composed of nested field types, but
  3248 of nested extension types. Therefore the record type only grows linear
  3249 in the number of extensions and not in the number of fields.  The
  3250 top-level (users) view on records is preserved.  Potential
  3251 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3252 old record representation. The type generated for a record is called
  3253 <record_name>_ext_type.
  3254 
  3255 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3256 proofs triggered by a record definition or a simproc (if
  3257 quick_and_dirty is enabled).  Definitions of large records can take
  3258 quite long.
  3259 
  3260 New simproc record_upd_simproc for simplification of multiple record
  3261 updates enabled by default.  Moreover, trivial updates are also
  3262 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3263 occasionally, since simplification is more powerful by default.
  3264 
  3265 * typedef: proper support for polymorphic sets, which contain extra
  3266 type-variables in the term.
  3267 
  3268 * Simplifier: automatically reasons about transitivity chains
  3269 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3270 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3271 old proofs break occasionally as simplification may now solve more
  3272 goals than previously.
  3273 
  3274 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3275 present.  Works for all partial orders (class "order"), in particular
  3276 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3277 just like y <= x.
  3278 
  3279 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3280 bound variable or a constant then the let is unfolded.  Otherwise
  3281 first a is simplified to b, and then f b is simplified to g. If
  3282 possible we abstract b from g arriving at "let x = b in h x",
  3283 otherwise we unfold the let and arrive at g.  The simproc can be
  3284 enabled/disabled by the reference use_let_simproc.  Potential
  3285 INCOMPATIBILITY since simplification is more powerful by default.
  3286 
  3287 * Classical reasoning: the meson method now accepts theorems as arguments.
  3288 
  3289 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3290 jobs to provide advice on the provability of subgoals.
  3291 
  3292 * Theory OrderedGroup and Ring_and_Field: various additions and
  3293 improvements to faciliate calculations involving equalities and
  3294 inequalities.
  3295 
  3296 The following theorems have been eliminated or modified
  3297 (INCOMPATIBILITY):
  3298 
  3299   abs_eq             now named abs_of_nonneg
  3300   abs_of_ge_0        now named abs_of_nonneg
  3301   abs_minus_eq       now named abs_of_nonpos
  3302   imp_abs_id         now named abs_of_nonneg
  3303   imp_abs_neg_id     now named abs_of_nonpos
  3304   mult_pos           now named mult_pos_pos
  3305   mult_pos_le        now named mult_nonneg_nonneg
  3306   mult_pos_neg_le    now named mult_nonneg_nonpos
  3307   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3308   mult_neg           now named mult_neg_neg
  3309   mult_neg_le        now named mult_nonpos_nonpos
  3310 
  3311 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3312      
  3313      zero_le_square
  3314      not_square_less_zero 
  3315 
  3316   The following lemmas have been deleted from Real/RealPow:
  3317   
  3318      realpow_zero_zero
  3319      realpow_two
  3320      realpow_less
  3321      zero_le_power
  3322      realpow_two_le
  3323      abs_realpow_two
  3324      realpow_two_abs     
  3325 
  3326 * Theory Parity: added rules for simplifying exponents.
  3327 
  3328 * Theory List:
  3329 
  3330 The following theorems have been eliminated or modified
  3331 (INCOMPATIBILITY):
  3332 
  3333   list_all_Nil       now named list_all.simps(1)
  3334   list_all_Cons      now named list_all.simps(2)
  3335   list_all_conv      now named list_all_iff
  3336   set_mem_eq         now named mem_iff
  3337 
  3338 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3339 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3340 
  3341 
  3342 *** HOL-Complex ***
  3343 
  3344 * Theory RealDef: better support for embedding natural numbers and
  3345 integers in the reals.
  3346 
  3347 The following theorems have been eliminated or modified
  3348 (INCOMPATIBILITY):
  3349 
  3350   exp_ge_add_one_self  now requires no hypotheses
  3351   real_of_int_add      reversed direction of equality (use [symmetric])
  3352   real_of_int_minus    reversed direction of equality (use [symmetric])
  3353   real_of_int_diff     reversed direction of equality (use [symmetric])
  3354   real_of_int_mult     reversed direction of equality (use [symmetric])
  3355 
  3356 * Theory RComplete: expanded support for floor and ceiling functions.
  3357 
  3358 * Theory Ln is new, with properties of the natural logarithm
  3359 
  3360 * Hyperreal: There is a new type constructor "star" for making
  3361 nonstandard types.  The old type names are now type synonyms:
  3362 
  3363   hypreal = real star
  3364   hypnat = nat star
  3365   hcomplex = complex star
  3366 
  3367 * Hyperreal: Many groups of similarly-defined constants have been
  3368 replaced by polymorphic versions (INCOMPATIBILITY):
  3369 
  3370   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3371 
  3372   starset      <-- starsetNat, starsetC
  3373   *s*          <-- *sNat*, *sc*
  3374   starset_n    <-- starsetNat_n, starsetC_n
  3375   *sn*         <-- *sNatn*, *scn*
  3376   InternalSets <-- InternalNatSets, InternalCSets
  3377 
  3378   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3379   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3380   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3381   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3382   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3383 
  3384 * Hyperreal: Many type-specific theorems have been removed in favor of
  3385 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3386 
  3387   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3388   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3389   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3390   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3391   right_minus <-- hypreal_add_minus
  3392   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3393   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3394   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3395   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3396   mult_1_right <-- hcomplex_mult_one_right
  3397   mult_zero_left <-- hcomplex_mult_zero_left
  3398   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3399   right_distrib <-- hypnat_add_mult_distrib2
  3400   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3401   right_inverse <-- hypreal_mult_inverse
  3402   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3403   order_refl <-- {hypreal,hypnat}_le_refl
  3404   order_trans <-- {hypreal,hypnat}_le_trans
  3405   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3406   order_less_le <-- {hypreal,hypnat}_less_le
  3407   linorder_linear <-- {hypreal,hypnat}_le_linear
  3408   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3409   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3410   add_nonneg_nonneg <-- hypreal_le_add_order
  3411 
  3412 * Hyperreal: Separate theorems having to do with type-specific
  3413 versions of constants have been merged into theorems that apply to the
  3414 new polymorphic constants (INCOMPATIBILITY):
  3415 
  3416   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3417   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3418   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3419   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3420   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3421   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3422   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3423   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3424   STAR_diff <-- {STAR,STARC}_diff
  3425   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3426     STARC_hcomplex_of_complex}_image_subset
  3427   starset_n_Un <-- starset{Nat,C}_n_Un
  3428   starset_n_Int <-- starset{Nat,C}_n_Int
  3429   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3430   starset_n_diff <-- starset{Nat,C}_n_diff
  3431   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3432   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3433   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3434   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3435   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3436   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3437   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3438   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3439   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3440   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3441   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3442   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3443   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3444   starfun_diff <-- starfun{C,RC,CR}_diff
  3445   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3446   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3447   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3448   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3449   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3450   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3451   starfun_Id <-- starfunC_Id
  3452   starfun_approx <-- starfun{Nat,CR}_approx
  3453   starfun_capprox <-- starfun{C,RC}_capprox
  3454   starfun_abs <-- starfunNat_rabs
  3455   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3456   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3457   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3458   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3459   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3460   starfun_add_approx <-- starfunCR_add_approx
  3461   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3462   starfun_divide <-- starfun{C,CR,RC}_divide
  3463   starfun_n <-- starfun{Nat,C}_n
  3464   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3465   starfun_n_add <-- starfun{Nat,C}_n_add
  3466   starfun_n_add_minus <-- starfunNat_n_add_minus
  3467   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3468   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3469   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3470 
  3471   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3472   star_n_minus <-- {hypreal,hcomplex}_minus
  3473   star_n_diff <-- {hypreal,hcomplex}_diff
  3474   star_n_mult <-- {hypreal,hcomplex}_mult
  3475   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3476   star_n_le <-- {hypreal,hypnat}_le
  3477   star_n_less <-- {hypreal,hypnat}_less
  3478   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3479   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3480   star_n_abs <-- hypreal_hrabs
  3481   star_n_divide <-- hcomplex_divide
  3482 
  3483   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3484   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3485   star_of_diff <-- hypreal_of_real_diff
  3486   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3487   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3488   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3489   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3490   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3491   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3492   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3493   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3494   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3495   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3496   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3497   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3498   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3499   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3500   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3501   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3502   star_of_power <-- hypreal_of_real_power
  3503   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3504 
  3505 * Hyperreal: new method "transfer" that implements the transfer
  3506 principle of nonstandard analysis. With a subgoal that mentions
  3507 nonstandard types like "'a star", the command "apply transfer"
  3508 replaces it with an equivalent one that mentions only standard types.
  3509 To be successful, all free variables must have standard types; non-
  3510 standard variables must have explicit universal quantifiers.
  3511 
  3512 * Hyperreal: A theory of Taylor series.
  3513 
  3514 
  3515 *** HOLCF ***
  3516 
  3517 * Discontinued special version of 'constdefs' (which used to support
  3518 continuous functions) in favor of the general Pure one with full
  3519 type-inference.
  3520 
  3521 * New simplification procedure for solving continuity conditions; it
  3522 is much faster on terms with many nested lambda abstractions (cubic
  3523 instead of exponential time).
  3524 
  3525 * New syntax for domain package: selector names are now optional.
  3526 Parentheses should be omitted unless argument is lazy, for example:
  3527 
  3528   domain 'a stream = cons "'a" (lazy "'a stream")
  3529 
  3530 * New command 'fixrec' for defining recursive functions with pattern
  3531 matching; defining multiple functions with mutual recursion is also
  3532 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3533 sinr, or any data constructor defined by the domain package. The given
  3534 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3535 syntax and examples.
  3536 
  3537 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3538 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3539 but the proof obligation additionally includes an admissibility
  3540 requirement. The packages generate instances of class cpo or pcpo,
  3541 with continuity and strictness theorems for Rep and Abs.
  3542 
  3543 * HOLCF: Many theorems have been renamed according to a more standard naming
  3544 scheme (INCOMPATIBILITY):
  3545 
  3546   foo_inject:  "foo$x = foo$y ==> x = y"
  3547   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3548   foo_less:    "(foo$x << foo$y) = (x << y)"
  3549   foo_strict:  "foo$UU = UU"
  3550   foo_defined: "... ==> foo$x ~= UU"
  3551   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3552 
  3553 
  3554 *** ZF ***
  3555 
  3556 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3557 including the First Isomorphism Theorem (on quotienting by the kernel
  3558 of a homomorphism).
  3559 
  3560 * ZF/Simplifier: install second copy of type solver that actually
  3561 makes use of TC rules declared to Isar proof contexts (or locales);
  3562 the old version is still required for ML proof scripts.
  3563 
  3564 
  3565 *** Cube ***
  3566 
  3567 * Converted to Isar theory format; use locales instead of axiomatic
  3568 theories.
  3569 
  3570 
  3571 *** ML ***
  3572 
  3573 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3574 for ||>, ||>>, |>>,
  3575 
  3576 * Pure/library.ML no longer defines its own option datatype, but uses
  3577 that of the SML basis, which has constructors NONE and SOME instead of
  3578 None and Some, as well as exception Option.Option instead of OPTION.
  3579 The functions the, if_none, is_some, is_none have been adapted
  3580 accordingly, while Option.map replaces apsome.
  3581 
  3582 * Pure/library.ML: the exception LIST has been given up in favour of
  3583 the standard exceptions Empty and Subscript, as well as
  3584 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3585 superceded by the standard hd and tl functions etc.
  3586 
  3587 A number of basic list functions are no longer exported to the ML
  3588 toplevel, as they are variants of predefined functions.  The following
  3589 suggests how one can translate existing code:
  3590 
  3591     rev_append xs ys = List.revAppend (xs, ys)
  3592     nth_elem (i, xs) = List.nth (xs, i)
  3593     last_elem xs = List.last xs
  3594     flat xss = List.concat xss
  3595     seq fs = List.app fs
  3596     partition P xs = List.partition P xs
  3597     mapfilter f xs = List.mapPartial f xs
  3598 
  3599 * Pure/library.ML: several combinators for linear functional
  3600 transformations, notably reverse application and composition:
  3601 
  3602   x |> f                f #> g
  3603   (x, y) |-> f          f #-> g
  3604 
  3605 * Pure/library.ML: introduced/changed precedence of infix operators:
  3606 
  3607   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3608   infix 2 ?;
  3609   infix 3 o oo ooo oooo;
  3610   infix 4 ~~ upto downto;
  3611 
  3612 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3613 infix operators.
  3614 
  3615 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3616 fold_map support linear functional transformations and nesting.  For
  3617 example:
  3618 
  3619   fold f [x1, ..., xN] y =
  3620     y |> f x1 |> ... |> f xN
  3621 
  3622   (fold o fold) f [xs1, ..., xsN] y =
  3623     y |> fold f xs1 |> ... |> fold f xsN
  3624 
  3625   fold f [x1, ..., xN] =
  3626     f x1 #> ... #> f xN
  3627 
  3628   (fold o fold) f [xs1, ..., xsN] =
  3629     fold f xs1 #> ... #> fold f xsN
  3630 
  3631 * Pure/library.ML: the following selectors on type 'a option are
  3632 available:
  3633 
  3634   the:               'a option -> 'a  (*partial*)
  3635   these:             'a option -> 'a  where 'a = 'b list
  3636   the_default: 'a -> 'a option -> 'a
  3637   the_list:          'a option -> 'a list
  3638 
  3639 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3640 basic operations for association lists, following natural argument
  3641 order; moreover the explicit equality predicate passed here avoids
  3642 potentially expensive polymorphic runtime equality checks.
  3643 The old functions may be expressed as follows:
  3644 
  3645   assoc = uncurry (AList.lookup (op =))
  3646   assocs = these oo AList.lookup (op =)
  3647   overwrite = uncurry (AList.update (op =)) o swap
  3648 
  3649 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3650 
  3651   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3652   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3653 
  3654 replacing make_keylist and keyfilter (occassionally used)
  3655 Naive rewrites:
  3656 
  3657   make_keylist = AList.make
  3658   keyfilter = AList.find (op =)
  3659 
  3660 * eq_fst and eq_snd now take explicit equality parameter, thus
  3661   avoiding eqtypes. Naive rewrites:
  3662 
  3663     eq_fst = eq_fst (op =)
  3664     eq_snd = eq_snd (op =)
  3665 
  3666 * Removed deprecated apl and apr (rarely used).
  3667   Naive rewrites:
  3668 
  3669     apl (n, op) =>>= curry op n
  3670     apr (op, m) =>>= fn n => op (n, m)
  3671 
  3672 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3673 provides a reasonably efficient light-weight implementation of sets as
  3674 lists.
  3675 
  3676 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3677 few new operations; existing lookup and update are now curried to
  3678 follow natural argument order (for use with fold etc.);
  3679 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3680 
  3681 * Pure/General: output via the Isabelle channels of
  3682 writeln/warning/error etc. is now passed through Output.output, with a
  3683 hook for arbitrary transformations depending on the print_mode
  3684 (cf. Output.add_mode -- the first active mode that provides a output
  3685 function wins).  Already formatted output may be embedded into further
  3686 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3687 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3688 accommodate easy composition of diagnostic messages etc.  Programmers
  3689 rarely need to care about Output.output or Output.raw at all, with
  3690 some notable exceptions: Output.output is required when bypassing the
  3691 standard channels (writeln etc.), or in token translations to produce
  3692 properly formatted results; Output.raw is required when capturing
  3693 already output material that will eventually be presented to the user
  3694 a second time.  For the default print mode, both Output.output and
  3695 Output.raw have no effect.
  3696 
  3697 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3698 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3699 cumulative results are displayed at the end of a batch session.
  3700 
  3701 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3702 replaced by File.platform_path and File.shell_path (with appropriate
  3703 hooks).  This provides a clean interface for unusual systems where the
  3704 internal and external process view of file names are different.
  3705 
  3706 * Pure: more efficient orders for basic syntactic entities: added
  3707 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3708 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3709 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3710 orders now -- potential INCOMPATIBILITY for code that depends on a
  3711 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3712 Library.sort_strings on result).
  3713 
  3714 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3715 fold_types traverse types/terms from left to right, observing natural
  3716 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3717 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3718 
  3719 * Pure: name spaces have been refined, with significant changes of the
  3720 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3721 to extern(_table).  The plain name entry path is superceded by a
  3722 general 'naming' context, which also includes the 'policy' to produce
  3723 a fully qualified name and external accesses of a fully qualified
  3724 name; NameSpace.extend is superceded by context dependent
  3725 Sign.declare_name.  Several theory and proof context operations modify
  3726 the naming context.  Especially note Theory.restore_naming and
  3727 ProofContext.restore_naming to get back to a sane state; note that
  3728 Theory.add_path is no longer sufficient to recover from
  3729 Theory.absolute_path in particular.
  3730 
  3731 * Pure: new flags short_names (default false) and unique_names
  3732 (default true) for controlling output of qualified names.  If
  3733 short_names is set, names are printed unqualified.  If unique_names is
  3734 reset, the name prefix is reduced to the minimum required to achieve
  3735 the original result when interning again, even if there is an overlap
  3736 with earlier declarations.
  3737 
  3738 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3739 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3740 (useful for printing error messages).  INCOMPATIBILITY.
  3741 
  3742 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3743 Theory.theory are now identified, referring to the universal
  3744 Context.theory (see Pure/context.ML).  Actual signature and theory
  3745 content is managed as theory data.  The old code and interfaces were
  3746 spread over many files and structures; the new arrangement introduces
  3747 considerable INCOMPATIBILITY to gain more clarity:
  3748 
  3749   Context -- theory management operations (name, identity, inclusion,
  3750     parents, ancestors, merge, etc.), plus generic theory data;
  3751 
  3752   Sign -- logical signature and syntax operations (declaring consts,
  3753     types, etc.), plus certify/read for common entities;
  3754 
  3755   Theory -- logical theory operations (stating axioms, definitions,
  3756     oracles), plus a copy of logical signature operations (consts,
  3757     types, etc.); also a few basic management operations (Theory.copy,
  3758     Theory.merge, etc.)
  3759 
  3760 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3761 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3762 for convenience -- they merely return the theory.
  3763 
  3764 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3765 
  3766 * Pure: the Isar proof context type is already defined early in Pure
  3767 as Context.proof (note that ProofContext.context and Proof.context are
  3768 aliases, where the latter is the preferred name).  This enables other
  3769 Isabelle components to refer to that type even before Isar is present.
  3770 
  3771 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3772 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3773 any of these kinds.  For example, Sign.intern typeK is now
  3774 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3775 Theory.hide_types.  Also note that former
  3776 Theory.hide_classes/types/consts are now
  3777 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3778 internalize their arguments!  INCOMPATIBILITY.
  3779 
  3780 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3781 datatype thmref (with constructors Name and NameSelection) instead of
  3782 plain string -- INCOMPATIBILITY;
  3783 
  3784 * Pure: cases produced by proof methods specify options, where NONE
  3785 means to remove case bindings -- INCOMPATIBILITY in
  3786 (RAW_)METHOD_CASES.
  3787 
  3788 * Pure: the following operations retrieve axioms or theorems from a
  3789 theory node or theory hierarchy, respectively:
  3790 
  3791   Theory.axioms_of: theory -> (string * term) list
  3792   Theory.all_axioms_of: theory -> (string * term) list
  3793   PureThy.thms_of: theory -> (string * thm) list
  3794   PureThy.all_thms_of: theory -> (string * thm) list
  3795 
  3796 * Pure: print_tac now outputs the goal through the trace channel.
  3797 
  3798 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3799 Reference Toplevel.debug (default false) controls detailed printing
  3800 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3801 controls execution profiling -- set to 1 for time and 2 for space
  3802 (both increase the runtime).
  3803 
  3804 * Isar session: The initial use of ROOT.ML is now always timed,
  3805 i.e. the log will show the actual process times, in contrast to the
  3806 elapsed wall-clock time that the outer shell wrapper produces.
  3807 
  3808 * Simplifier: improved handling of bound variables (nameless
  3809 representation, avoid allocating new strings).  Simprocs that invoke
  3810 the Simplifier recursively should use Simplifier.inherit_bounds to
  3811 avoid local name clashes.  Failure to do so produces warnings
  3812 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3813 for further details.
  3814 
  3815 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3816 bindings for all theorems stored within a given theory; this may help
  3817 in porting non-Isar theories to Isar ones, while keeping ML proof
  3818 scripts for the time being.
  3819 
  3820 * ML operator HTML.with_charset specifies the charset begin used for
  3821 generated HTML files.  For example:
  3822 
  3823   HTML.with_charset "utf-8" use_thy "Hebrew";
  3824   HTML.with_charset "utf-8" use_thy "Chinese";
  3825 
  3826 
  3827 *** System ***
  3828 
  3829 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3830 isabelle, isatool etc.).
  3831 
  3832 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3833 isatool doc, isatool mkdir, display_drafts etc.).
  3834 
  3835 * isatool usedir: option -f allows specification of the ML file to be
  3836 used by Isabelle; default is ROOT.ML.
  3837 
  3838 * New isatool version outputs the version identifier of the Isabelle
  3839 distribution being used.
  3840 
  3841 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3842 (containing Boolean satisfiability problems) into Isabelle/HOL
  3843 theories.
  3844 
  3845 
  3846 
  3847 New in Isabelle2004 (April 2004)
  3848 --------------------------------
  3849 
  3850 *** General ***
  3851 
  3852 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3853   Replaces linorder.ML.
  3854 
  3855 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3856   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3857   (\<a>...\<z>), are now considered normal letters, and can therefore
  3858   be used anywhere where an ASCII letter (a...zA...Z) has until
  3859   now. COMPATIBILITY: This obviously changes the parsing of some
  3860   terms, especially where a symbol has been used as a binder, say
  3861   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3862   as an identifier.  Fix it by inserting a space around former
  3863   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3864   existing theory and ML files.
  3865 
  3866 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3867 
  3868 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3869   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3870   a normal (but invisible) letter. For multiple letter subscripts repeat
  3871   \<^isub> like this: x\<^isub>1\<^isub>2.
  3872 
  3873 * Pure: There are now sub-/superscripts that can span more than one
  3874   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3875   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3876   superscript. The new control characters are not identifier parts.
  3877 
  3878 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3879   content of "..." to the latex file instead of \isacntrl... . The "..."
  3880   may consist of any printable characters excluding the end bracket >.
  3881 
  3882 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3883   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3884   declare constants "final", which prevents their being given a definition
  3885   later.  It is useful for constants whose behaviour is fixed axiomatically
  3886   rather than definitionally, such as the meta-logic connectives.
  3887 
  3888 * Pure: 'instance' now handles general arities with general sorts
  3889   (i.e. intersections of classes),
  3890 
  3891 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3892   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3893   It can be changed to alter the colors/layout of generated pages.
  3894 
  3895 
  3896 *** Isar ***
  3897 
  3898 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3899   cut_tac, subgoal_tac and thin_tac:
  3900   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3901     locales are no longer forced to write Isar proof scripts.
  3902     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3903     emulations.
  3904   - INCOMPATIBILITY: names of variables to be instantiated may no
  3905     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3906     This is consistent with the instantiation attribute "where".
  3907 
  3908 * Attributes "where" and "of":
  3909   - Now take type variables of instantiated theorem into account when reading
  3910     the instantiation string.  This fixes a bug that caused instantiated
  3911     theorems to have too special types in some circumstances.
  3912   - "where" permits explicit instantiations of type variables.
  3913 
  3914 * Calculation commands "moreover" and "also" no longer interfere with
  3915   current facts ("this"), admitting arbitrary combinations with "then"
  3916   and derived forms.
  3917 
  3918 * Locales:
  3919   - Goal statements involving the context element "includes" no longer
  3920     generate theorems with internal delta predicates (those ending on
  3921     "_axioms") in the premise.
  3922     Resolve particular premise with <locale>.intro to obtain old form.
  3923   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3924     specification and "includes" elements in goal statement.
  3925   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3926     [intro?] and [elim?] (respectively) by default.
  3927   - Experimental command for instantiation of locales in proof contexts:
  3928         instantiate <label>[<attrs>]: <loc>
  3929     Instantiates locale <loc> and adds all its theorems to the current context
  3930     taking into account their attributes.  Label and attrs are optional
  3931     modifiers, like in theorem declarations.  If present, names of
  3932     instantiated theorems are qualified with <label>, and the attributes
  3933     <attrs> are applied after any attributes these theorems might have already.
  3934       If the locale has assumptions, a chained fact of the form
  3935     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3936     are derived.  The command does not support old-style locales declared
  3937     with "locale (open)".
  3938       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3939 
  3940 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3941   (Isar) contexts.
  3942 
  3943 
  3944 *** HOL ***
  3945 
  3946 * Proof import: new image HOL4 contains the imported library from
  3947   the HOL4 system with about 2500 theorems. It is imported by
  3948   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3949   can be used like any other Isabelle image.  See
  3950   HOL/Import/HOL/README for more information.
  3951 
  3952 * Simplifier:
  3953   - Much improved handling of linear and partial orders.
  3954     Reasoners for linear and partial orders are set up for type classes
  3955     "linorder" and "order" respectively, and are added to the default simpset
  3956     as solvers.  This means that the simplifier can build transitivity chains
  3957     to solve goals from the assumptions.
  3958   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3959     of blast or auto after simplification become unnecessary because the goal
  3960     is solved by simplification already.
  3961 
  3962 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3963     all proved in axiomatic type classes for semirings, rings and fields.
  3964 
  3965 * Numerics:
  3966   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3967     now formalized using the Ring_and_Field theory mentioned above.
  3968   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3969     than before, because now they are set up once in a generic manner.
  3970   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3971     Look for the general versions in Ring_and_Field (and Power if they concern
  3972     exponentiation).
  3973 
  3974 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3975 
  3976 * Records:
  3977   - Record types are now by default printed with their type abbreviation
  3978     instead of the list of all field types. This can be configured via
  3979     the reference "print_record_type_abbr".
  3980   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3981     (not enabled by default).
  3982   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3983     EX x. x = sel r to True (not enabled by default).
  3984   - Tactic "record_split_simp_tac" to split and simplify records added.
  3985 
  3986 * 'specification' command added, allowing for definition by
  3987   specification.  There is also an 'ax_specification' command that
  3988   introduces the new constants axiomatically.
  3989 
  3990 * arith(_tac) is now able to generate counterexamples for reals as well.
  3991 
  3992 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3993 
  3994 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3995   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3996 
  3997 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3998   matrix theory to linear programming.
  3999 
  4000 * Unions and Intersections:
  4001   The latex output syntax of UN and INT has been changed
  4002   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4003   i.e. the index formulae has become a subscript.
  4004   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4005 
  4006 * Unions and Intersections over Intervals:
  4007   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4008   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4009   like in normal math, and corresponding versions for < and for intersection.
  4010 
  4011 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4012   lexicographic dictonary ordering has been added as "lexord".
  4013 
  4014 * ML: the legacy theory structures Int and List have been removed. They had
  4015   conflicted with ML Basis Library structures having the same names.
  4016 
  4017 * 'refute' command added to search for (finite) countermodels.  Only works
  4018   for a fragment of HOL.  The installation of an external SAT solver is
  4019   highly recommended.  See "HOL/Refute.thy" for details.
  4020 
  4021 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4022   formulae under an assignment of free variables to random values.
  4023   In contrast to 'refute', it can deal with inductive datatypes,
  4024   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4025   for examples.
  4026 
  4027 
  4028 *** HOLCF ***
  4029 
  4030 * Streams now come with concatenation and are part of the HOLCF image
  4031 
  4032 
  4033 
  4034 New in Isabelle2003 (May 2003)
  4035 ------------------------------
  4036 
  4037 *** General ***
  4038 
  4039 * Provers/simplifier:
  4040 
  4041   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4042     Assumptions are now subject to complete mutual simplification,
  4043     not just from left to right. The simplifier now preserves
  4044     the order of assumptions.
  4045 
  4046     Potential INCOMPATIBILITY:
  4047 
  4048     -- simp sometimes diverges where the old version did
  4049        not, e.g. invoking simp on the goal
  4050 
  4051         [| P (f x); y = x; f x = f y |] ==> Q
  4052 
  4053        now gives rise to the infinite reduction sequence
  4054 
  4055         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4056 
  4057        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4058        kind of problem.
  4059 
  4060     -- Tactics combining classical reasoner and simplification (such as auto)
  4061        are also affected by this change, because many of them rely on
  4062        simp. They may sometimes diverge as well or yield a different numbers
  4063        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4064        in case of problems. Sometimes subsequent calls to the classical
  4065        reasoner will fail because a preceeding call to the simplifier too
  4066        eagerly simplified the goal, e.g. deleted redundant premises.
  4067 
  4068   - The simplifier trace now shows the names of the applied rewrite rules
  4069 
  4070   - You can limit the number of recursive invocations of the simplifier
  4071     during conditional rewriting (where the simplifie tries to solve the
  4072     conditions before applying the rewrite rule):
  4073     ML "simp_depth_limit := n"
  4074     where n is an integer. Thus you can force termination where previously
  4075     the simplifier would diverge.
  4076 
  4077   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4078 
  4079   - No longer aborts on failed congruence proof.  Instead, the
  4080     congruence is ignored.
  4081 
  4082 * Pure: New generic framework for extracting programs from constructive
  4083   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4084   as HOL/Extraction for some case studies.
  4085 
  4086 * Pure: The main goal of the proof state is no longer shown by default, only
  4087 the subgoals. This behaviour is controlled by a new flag.
  4088    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4089 (ML: Proof.show_main_goal).
  4090 
  4091 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4092 rules whose conclusion matches subgoal 1:
  4093       PG menu: Isabelle/Isar -> Show me -> matching rules
  4094 The rules are ordered by how closely they match the subgoal.
  4095 In particular, rules that solve a subgoal outright are displayed first
  4096 (or rather last, the way they are printed).
  4097 (ML: ProofGeneral.print_intros())
  4098 
  4099 * Pure: New flag trace_unify_fail causes unification to print
  4100 diagnostic information (PG: in trace buffer) when it fails. This is
  4101 useful for figuring out why single step proofs like rule, erule or
  4102 assumption failed.
  4103 
  4104 * Pure: Locale specifications now produce predicate definitions
  4105 according to the body of text (covering assumptions modulo local
  4106 definitions); predicate "loc_axioms" covers newly introduced text,
  4107 while "loc" is cumulative wrt. all included locale expressions; the
  4108 latter view is presented only on export into the global theory
  4109 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4110 on the old view without predicates;
  4111 
  4112 * Pure: predefined locales "var" and "struct" are useful for sharing
  4113 parameters (as in CASL, for example); just specify something like
  4114 ``var x + var y + struct M'' as import;
  4115 
  4116 * Pure: improved thms_containing: proper indexing of facts instead of
  4117 raw theorems; check validity of results wrt. current name space;
  4118 include local facts of proof configuration (also covers active
  4119 locales), cover fixed variables in index; may use "_" in term
  4120 specification; an optional limit for the number of printed facts may
  4121 be given (the default is 40);
  4122 
  4123 * Pure: disallow duplicate fact bindings within new-style theory files
  4124 (batch-mode only);
  4125 
  4126 * Provers: improved induct method: assumptions introduced by case
  4127 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4128 the goal statement); "foo" still refers to all facts collectively;
  4129 
  4130 * Provers: the function blast.overloaded has been removed: all constants
  4131 are regarded as potentially overloaded, which improves robustness in exchange
  4132 for slight decrease in efficiency;
  4133 
  4134 * Provers/linorder: New generic prover for transitivity reasoning over
  4135 linear orders.  Note: this prover is not efficient!
  4136 
  4137 * Isar: preview of problems to finish 'show' now produce an error
  4138 rather than just a warning (in interactive mode);
  4139 
  4140 
  4141 *** HOL ***
  4142 
  4143 * arith(_tac)
  4144 
  4145  - Produces a counter example if it cannot prove a goal.
  4146    Note that the counter example may be spurious if the goal is not a formula
  4147    of quantifier-free linear arithmetic.
  4148    In ProofGeneral the counter example appears in the trace buffer.
  4149 
  4150  - Knows about div k and mod k where k is a numeral of type nat or int.
  4151 
  4152  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4153    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4154    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4155 
  4156 * simp's arithmetic capabilities have been enhanced a bit: it now
  4157 takes ~= in premises into account (by performing a case split);
  4158 
  4159 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4160 are distributed over a sum of terms;
  4161 
  4162 * New tactic "trans_tac" and method "trans" instantiate
  4163 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4164 "<=", "<" and "=").
  4165 
  4166 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4167 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4168 
  4169 * 'typedef' command has new option "open" to suppress the set
  4170 definition;
  4171 
  4172 * functions Min and Max on finite sets have been introduced (theory
  4173 Finite_Set);
  4174 
  4175 * attribute [symmetric] now works for relations as well; it turns
  4176 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4177 
  4178 * induct over a !!-quantified statement (say !!x1..xn):
  4179   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4180 
  4181 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4182 %x. None. Warning: empty_def now refers to the previously hidden definition
  4183 of the empty set.
  4184 
  4185 * Algebra: formalization of classical algebra.  Intended as base for
  4186 any algebraic development in Isabelle.  Currently covers group theory
  4187 (up to Sylow's theorem) and ring theory (Universal Property of
  4188 Univariate Polynomials).  Contributions welcome;
  4189 
  4190 * GroupTheory: deleted, since its material has been moved to Algebra;
  4191 
  4192 * Complex: new directory of the complex numbers with numeric constants,
  4193 nonstandard complex numbers, and some complex analysis, standard and
  4194 nonstandard (Jacques Fleuriot);
  4195 
  4196 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4197 
  4198 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4199 Fleuriot);
  4200 
  4201 * Real/HahnBanach: updated and adapted to locales;
  4202 
  4203 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4204 Gray and Kramer);
  4205 
  4206 * UNITY: added the Meier-Sanders theory of progress sets;
  4207 
  4208 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4209 as abstract algorithms, instantiated to the JVM;
  4210 
  4211 * Bali: Java source language formalization. Type system, operational
  4212 semantics, axiomatic semantics. Supported language features:
  4213 classes, interfaces, objects,virtual methods, static methods,
  4214 static/instance fields, arrays, access modifiers, definite
  4215 assignment, exceptions.
  4216 
  4217 
  4218 *** ZF ***
  4219 
  4220 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4221 universe, etc.);
  4222 
  4223 * Main ZF: virtually all theories converted to new-style format;
  4224 
  4225 
  4226 *** ML ***
  4227 
  4228 * Pure: Tactic.prove provides sane interface for internal proofs;
  4229 omits the infamous "standard" operation, so this is more appropriate
  4230 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4231 
  4232 * Pure: improved error reporting of simprocs;
  4233 
  4234 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4235 up simprocs;
  4236 
  4237 
  4238 *** Document preparation ***
  4239 
  4240 * uses \par instead of \\ for line breaks in theory text. This may
  4241 shift some page breaks in large documents. To get the old behaviour
  4242 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4243 
  4244 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4245 other packages
  4246 
  4247 * \<euro> now needs package babel/greek instead of marvosym (which
  4248 broke \Rightarrow)
  4249 
  4250 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4251 textcomp package)
  4252 
  4253 
  4254 
  4255 New in Isabelle2002 (March 2002)
  4256 --------------------------------
  4257 
  4258 *** Document preparation ***
  4259 
  4260 * greatly simplified document preparation setup, including more
  4261 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4262 instructive isatool mkdir; users should basically be able to get
  4263 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4264 users may run a separate document processing stage manually like this:
  4265 "isatool usedir -D output HOL Test && isatool document Test/output";
  4266 
  4267 * theory dependency graph may now be incorporated into documents;
  4268 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4269 with \includegraphics of LaTeX;
  4270 
  4271 * proper spacing of consecutive markup elements, especially text
  4272 blocks after section headings;
  4273 
  4274 * support bold style (for single symbols only), input syntax is like
  4275 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4276 
  4277 * \<bullet> is now output as bold \cdot by default, which looks much
  4278 better in printed text;
  4279 
  4280 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4281 note that these symbols are currently unavailable in Proof General /
  4282 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4283 
  4284 * isatool latex no longer depends on changed TEXINPUTS, instead
  4285 isatool document copies the Isabelle style files to the target
  4286 location;
  4287 
  4288 
  4289 *** Isar ***
  4290 
  4291 * Pure/Provers: improved proof by cases and induction;
  4292   - 'case' command admits impromptu naming of parameters (such as
  4293     "case (Suc n)");
  4294   - 'induct' method divinates rule instantiation from the inductive
  4295     claim; no longer requires excessive ?P bindings for proper
  4296     instantiation of cases;
  4297   - 'induct' method properly enumerates all possibilities of set/type
  4298     rules; as a consequence facts may be also passed through *type*
  4299     rules without further ado;
  4300   - 'induct' method now derives symbolic cases from the *rulified*
  4301     rule (before it used to rulify cases stemming from the internal
  4302     atomized version); this means that the context of a non-atomic
  4303     statement becomes is included in the hypothesis, avoiding the
  4304     slightly cumbersome show "PROP ?case" form;
  4305   - 'induct' may now use elim-style induction rules without chaining
  4306     facts, using ``missing'' premises from the goal state; this allows
  4307     rules stemming from inductive sets to be applied in unstructured
  4308     scripts, while still benefitting from proper handling of non-atomic
  4309     statements; NB: major inductive premises need to be put first, all
  4310     the rest of the goal is passed through the induction;
  4311   - 'induct' proper support for mutual induction involving non-atomic
  4312     rule statements (uses the new concept of simultaneous goals, see
  4313     below);
  4314   - append all possible rule selections, but only use the first
  4315     success (no backtracking);
  4316   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4317   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4318   - added 'print_induct_rules' (covered by help item in recent Proof
  4319     General versions);
  4320   - moved induct/cases attributes to Pure, methods to Provers;
  4321   - generic method setup instantiated for FOL and HOL;
  4322 
  4323 * Pure: support multiple simultaneous goal statements, for example
  4324 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4325 meta-level mechanism, this acts as if several individual goals had
  4326 been stated separately; in particular common proof methods need to be
  4327 repeated in order to cover all claims; note that a single elimination
  4328 step is *not* sufficient to establish the two conjunctions, so this
  4329 fails:
  4330 
  4331   assume "A & B" then have A and B ..   (*".." fails*)
  4332 
  4333 better use "obtain" in situations as above; alternative refer to
  4334 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4335 
  4336 * Pure: proper integration with ``locales''; unlike the original
  4337 version by Florian Kammller, Isar locales package high-level proof
  4338 contexts rather than raw logical ones (e.g. we admit to include
  4339 attributes everywhere); operations on locales include merge and
  4340 rename; support for implicit arguments (``structures''); simultaneous
  4341 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4342 some examples;
  4343 
  4344 * Pure: the following commands have been ``localized'', supporting a
  4345 target locale specification "(in name)": 'lemma', 'theorem',
  4346 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4347 stored both within the locale and at the theory level (exported and
  4348 qualified by the locale name);
  4349 
  4350 * Pure: theory goals may now be specified in ``long'' form, with
  4351 ad-hoc contexts consisting of arbitrary locale elements. for example
  4352 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4353 definitions may be given, too); the result is a meta-level rule with
  4354 the context elements being discharged in the obvious way;
  4355 
  4356 * Pure: new proof command 'using' allows to augment currently used
  4357 facts after a goal statement ('using' is syntactically analogous to
  4358 'apply', but acts on the goal's facts only); this allows chained facts
  4359 to be separated into parts given before and after a claim, as in
  4360 ``from a and b have C using d and e <proof>'';
  4361 
  4362 * Pure: renamed "antecedent" case to "rule_context";
  4363 
  4364 * Pure: new 'judgment' command records explicit information about the
  4365 object-logic embedding (used by several tools internally); no longer
  4366 use hard-wired "Trueprop";
  4367 
  4368 * Pure: added 'corollary' command;
  4369 
  4370 * Pure: fixed 'token_translation' command;
  4371 
  4372 * Pure: removed obsolete 'exported' attribute;
  4373 
  4374 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4375 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4376 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4377 
  4378 * Pure: method 'atomize' presents local goal premises as object-level
  4379 statements (atomic meta-level propositions); setup controlled via
  4380 rewrite rules declarations of 'atomize' attribute; example
  4381 application: 'induct' method with proper rule statements in improper
  4382 proof *scripts*;
  4383 
  4384 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4385 now consider the syntactic context of assumptions, giving a better
  4386 chance to get type-inference of the arguments right (this is
  4387 especially important for locales);
  4388 
  4389 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4390 mode;
  4391 
  4392 * Pure/obtain: the formal conclusion "thesis", being marked as
  4393 ``internal'', may no longer be reference directly in the text;
  4394 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4395 situations;
  4396 
  4397 * Pure: generic 'sym' attribute which declares a rule both as pure
  4398 'elim?' and for the 'symmetric' operation;
  4399 
  4400 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4401 text; the fixed correlation with particular command syntax has been
  4402 discontinued;
  4403 
  4404 * Pure: new method 'rules' is particularly well-suited for proof
  4405 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4406 but often produces more compact proof terms with less detours;
  4407 
  4408 * Pure/Provers/classical: simplified integration with pure rule
  4409 attributes and methods; the classical "intro?/elim?/dest?"
  4410 declarations coincide with the pure ones; the "rule" method no longer
  4411 includes classically swapped intros; "intro" and "elim" methods no
  4412 longer pick rules from the context; also got rid of ML declarations
  4413 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4414 INCOMPATIBILITY;
  4415 
  4416 * Provers/classical: attribute 'swapped' produces classical inversions
  4417 of introduction rules;
  4418 
  4419 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4420 rules instead of full simplifier context; 'iff' attribute handles
  4421 conditional rules;
  4422 
  4423 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4424 
  4425 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4426 "(permissive)" option to recover old behavior;
  4427 
  4428 * HOL: 'inductive' no longer features separate (collective) attributes
  4429 for 'intros' (was found too confusing);
  4430 
  4431 * HOL: properly declared induction rules less_induct and
  4432 wf_induct_rule;
  4433 
  4434 
  4435 *** HOL ***
  4436 
  4437 * HOL: moved over to sane numeral syntax; the new policy is as
  4438 follows:
  4439 
  4440   - 0 and 1 are polymorphic constants, which are defined on any
  4441   numeric type (nat, int, real etc.);
  4442 
  4443   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4444   binary representation internally;
  4445 
  4446   - type nat has special constructor Suc, and generally prefers Suc 0
  4447   over 1::nat and Suc (Suc 0) over 2::nat;
  4448 
  4449 This change may cause significant problems of INCOMPATIBILITY; here
  4450 are some hints on converting existing sources:
  4451 
  4452   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4453   entities, so expressions involving "-" (unary or binary minus) need
  4454   to be spaced properly;
  4455 
  4456   - existing occurrences of "1" may need to be constraint "1::nat" or
  4457   even replaced by Suc 0; similar for old "2";
  4458 
  4459   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4460 
  4461   - remove all special provisions on numerals in proofs;
  4462 
  4463 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4464 representation (depends on bin_arith_simps in the default context);
  4465 
  4466 * HOL: symbolic syntax for x^2 (numeral 2);
  4467 
  4468 * HOL: the class of all HOL types is now called "type" rather than
  4469 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4470 in axclass/classes, instance/arities, and (usually rare) occurrences
  4471 in typings (of consts etc.); internally the class is called
  4472 "HOL.type", ML programs should refer to HOLogic.typeS;
  4473 
  4474 * HOL/record package improvements:
  4475   - new derived operations "fields" to build a partial record section,
  4476     "extend" to promote a fixed record to a record scheme, and
  4477     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4478     declared as simp by default;
  4479   - shared operations ("more", "fields", etc.) now need to be always
  4480     qualified) --- potential INCOMPATIBILITY;
  4481   - removed "make_scheme" operations (use "make" with "extend") --
  4482     INCOMPATIBILITY;
  4483   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4484   - provides cases/induct rules for use with corresponding Isar
  4485     methods (for concrete records, record schemes, concrete more
  4486     parts, and schematic more parts -- in that order);
  4487   - internal definitions directly based on a light-weight abstract
  4488     theory of product types over typedef rather than datatype;
  4489 
  4490 * HOL: generic code generator for generating executable ML code from
  4491 specifications; specific support for HOL constructs such as inductive
  4492 datatypes and sets, as well as recursive functions; can be invoked
  4493 via 'generate_code' theory section;
  4494 
  4495 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4496 
  4497 * HOL: consolidated and renamed several theories.  In particular:
  4498         Ord.thy has been absorbed into HOL.thy
  4499         String.thy has been absorbed into List.thy
  4500 
  4501 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4502 (beware of argument permutation!);
  4503 
  4504 * HOL: linorder_less_split superseded by linorder_cases;
  4505 
  4506 * HOL/List: "nodups" renamed to "distinct";
  4507 
  4508 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4509 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4510   - Ex_def has changed, now need to use some_eq_ex
  4511 
  4512 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4513 in this (rare) case use:
  4514 
  4515   delSWrapper "split_all_tac"
  4516   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4517 
  4518 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4519 MAY FAIL;
  4520 
  4521 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4522 Isabelle's type classes, ^ on functions and relations has too general
  4523 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4524 necessary to attach explicit type constraints;
  4525 
  4526 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4527 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4528 renamed accordingly (eg "compI" -> "rel_compI").
  4529 
  4530 * HOL: syntax translations now work properly with numerals and records
  4531 expressions;
  4532 
  4533 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4534 of "lam" -- INCOMPATIBILITY;
  4535 
  4536 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4537 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4538 renamed "Product_Type.unit";
  4539 
  4540 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4541 
  4542 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4543 the "cases" method);
  4544 
  4545 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4546 Florian Kammller);
  4547 
  4548 * HOL/IMP: updated and converted to new-style theory format; several
  4549 parts turned into readable document, with proper Isar proof texts and
  4550 some explanations (by Gerwin Klein);
  4551 
  4552 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4553 
  4554 * HOL-Hyperreal is now a logic image;
  4555 
  4556 
  4557 *** HOLCF ***
  4558 
  4559 * Isar: consts/constdefs supports mixfix syntax for continuous
  4560 operations;
  4561 
  4562 * Isar: domain package adapted to new-style theory format, e.g. see
  4563 HOLCF/ex/Dnat.thy;
  4564 
  4565 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4566 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4567 lift.induct_tac, always use UU instead of Undef;
  4568 
  4569 * HOLCF/IMP: updated and converted to new-style theory;
  4570 
  4571 
  4572 *** ZF ***
  4573 
  4574 * Isar: proper integration of logic-specific tools and packages,
  4575 including theory commands '(co)inductive', '(co)datatype',
  4576 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4577 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4578 
  4579 * theory Main no longer includes AC; for the Axiom of Choice, base
  4580 your theory on Main_ZFC;
  4581 
  4582 * the integer library now covers quotients and remainders, with many
  4583 laws relating division to addition, multiplication, etc.;
  4584 
  4585 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4586 typeless version of the formalism;
  4587 
  4588 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4589 format;
  4590 
  4591 * ZF/Induct: new directory for examples of inductive definitions,
  4592 including theory Multiset for multiset orderings; converted to
  4593 new-style theory format;
  4594 
  4595 * ZF: many new theorems about lists, ordinals, etc.;
  4596 
  4597 
  4598 *** General ***
  4599 
  4600 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4601 variable proof controls level of detail: 0 = no proofs (only oracle
  4602 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4603 also ref manual for further ML interfaces;
  4604 
  4605 * Pure/axclass: removed obsolete ML interface
  4606 goal_subclass/goal_arity;
  4607 
  4608 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4609 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4610 separate tokens, so expressions involving minus need to be spaced
  4611 properly;
  4612 
  4613 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4614 rather than "infixl" or "infixr";
  4615 
  4616 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4617 sort constraint specifications in type inference; e.g. "x::_::foo"
  4618 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4619 type variable);
  4620 
  4621 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4622 control output of nested => (types); the default behavior is
  4623 "type_brackets";
  4624 
  4625 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4626 tokens into AST constants;
  4627 
  4628 * Pure/syntax: prefer later declarations of translations and print
  4629 translation functions; potential INCOMPATIBILITY: need to reverse
  4630 multiple declarations for same syntax element constant;
  4631 
  4632 * Pure/show_hyps reset by default (in accordance to existing Isar
  4633 practice);
  4634 
  4635 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4636 addSafter;
  4637 
  4638 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4639 as well;
  4640 
  4641 * system: tested support for MacOS X; should be able to get Isabelle +
  4642 Proof General to work in a plain Terminal after installing Poly/ML
  4643 (e.g. from the Isabelle distribution area) and GNU bash alone
  4644 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4645 support requires further installations, e.g. from
  4646 http://fink.sourceforge.net/);
  4647 
  4648 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4649 
  4650 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4651 of 40 MB), cf. ML_OPTIONS;
  4652 
  4653 * system: Proof General keywords specification is now part of the
  4654 Isabelle distribution (see etc/isar-keywords.el);
  4655 
  4656 * system: support for persistent Proof General sessions (refrain from
  4657 outdating all loaded theories on startup); user may create writable
  4658 logic images like this: ``isabelle -q HOL Test'';
  4659 
  4660 * system: smart selection of Isabelle process versus Isabelle
  4661 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4662 run both "isabelle" and "Isabelle" even if file names are badly
  4663 damaged (executable inspects the case of the first letter of its own
  4664 name); added separate "isabelle-process" and "isabelle-interface";
  4665 
  4666 * system: refrain from any attempt at filtering input streams; no
  4667 longer support ``8bit'' encoding of old isabelle font, instead proper
  4668 iso-latin characters may now be used; the related isatools
  4669 "symbolinput" and "nonascii" have disappeared as well;
  4670 
  4671 * system: removed old "xterm" interface (the print modes "xterm" and
  4672 "xterm_color" are still available for direct use in a suitable
  4673 terminal);
  4674 
  4675 
  4676 
  4677 New in Isabelle99-2 (February 2001)
  4678 -----------------------------------
  4679 
  4680 *** Overview of INCOMPATIBILITIES ***
  4681 
  4682 * HOL: please note that theories in the Library and elsewhere often use the
  4683 new-style (Isar) format; to refer to their theorems in an ML script you must
  4684 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4685 
  4686 * HOL: inductive package no longer splits induction rule aggressively,
  4687 but only as far as specified by the introductions given; the old
  4688 format may be recovered via ML function complete_split_rule or attribute
  4689 'split_rule (complete)';
  4690 
  4691 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4692 gfp_Tarski to gfp_unfold;
  4693 
  4694 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4695 
  4696 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4697 relation); infix "^^" has been renamed "``"; infix "``" has been
  4698 renamed "`"; "univalent" has been renamed "single_valued";
  4699 
  4700 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4701 operation;
  4702 
  4703 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4704 
  4705 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4706 
  4707 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4708 consequence, it is no longer monotonic wrt. the local goal context
  4709 (which is now passed through the inductive cases);
  4710 
  4711 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4712 \<gg> to \<ggreater>;
  4713 
  4714 
  4715 *** Document preparation ***
  4716 
  4717 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4718 available: are "it" for near math-mode best-style output, "sl" for
  4719 slanted text style, and "tt" for plain type-writer; if no
  4720 \isabellestyle command is given, output is according to slanted
  4721 type-writer);
  4722 
  4723 * support sub/super scripts (for single symbols only), input syntax is
  4724 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4725 
  4726 * some more standard symbols; see Appendix A of the system manual for
  4727 the complete list of symbols defined in isabellesym.sty;
  4728 
  4729 * improved isabelle style files; more abstract symbol implementation
  4730 (should now use \isamath{...} and \isatext{...} in custom symbol
  4731 definitions);
  4732 
  4733 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4734 state; Note that presentation of goal states does not conform to
  4735 actual human-readable proof documents.  Please do not include goal
  4736 states into document output unless you really know what you are doing!
  4737 
  4738 * proper indentation of antiquoted output with proportional LaTeX
  4739 fonts;
  4740 
  4741 * no_document ML operator temporarily disables LaTeX document
  4742 generation;
  4743 
  4744 * isatool unsymbolize tunes sources for plain ASCII communication;
  4745 
  4746 
  4747 *** Isar ***
  4748 
  4749 * Pure: Isar now suffers initial goal statements to contain unbound
  4750 schematic variables (this does not conform to actual readable proof
  4751 documents, due to unpredictable outcome and non-compositional proof
  4752 checking); users who know what they are doing may use schematic goals
  4753 for Prolog-style synthesis of proven results;
  4754 
  4755 * Pure: assumption method (an implicit finishing) now handles actual
  4756 rules as well;
  4757 
  4758 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4759 initial goal, declare "that" only as Pure intro (only for single
  4760 steps); the "that" rule assumption may now be involved in implicit
  4761 finishing, thus ".." becomes a feasible for trivial obtains;
  4762 
  4763 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4764 instance proofs may be performed by "..";
  4765 
  4766 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4767 statements as well;
  4768 
  4769 * Pure: more robust selection of calculational rules;
  4770 
  4771 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4772 rule (as well as the assumption rule);
  4773 
  4774 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4775 lemmas, using the graph browser tool;
  4776 
  4777 * Pure: predict failure of "show" in interactive mode;
  4778 
  4779 * Pure: 'thms_containing' now takes actual terms as arguments;
  4780 
  4781 * HOL: improved method 'induct' --- now handles non-atomic goals
  4782 (potential INCOMPATIBILITY); tuned error handling;
  4783 
  4784 * HOL: cases and induct rules now provide explicit hints about the
  4785 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4786 any remaining facts are inserted into the goal verbatim;
  4787 
  4788 * HOL: local contexts (aka cases) may now contain term bindings as
  4789 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4790 the result to be shown in each case;
  4791 
  4792 * HOL: added 'recdef_tc' command;
  4793 
  4794 * isatool convert assists in eliminating legacy ML scripts;
  4795 
  4796 
  4797 *** HOL ***
  4798 
  4799 * HOL/Library: a collection of generic theories to be used together
  4800 with main HOL; the theory loader path already includes this directory
  4801 by default; the following existing theories have been moved here:
  4802 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4803 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4804 
  4805 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4806 modelling and verification task performed in Isabelle/HOL +
  4807 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4808 
  4809 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4810 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4811 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4812 'domain', this makes the theory consistent with mathematical
  4813 literature;
  4814 
  4815 * HOL basics: added overloaded operations "inverse" and "divide"
  4816 (infix "/"), syntax for generic "abs" operation, generic summation
  4817 operator \<Sum>;
  4818 
  4819 * HOL/typedef: simplified package, provide more useful rules (see also
  4820 HOL/subset.thy);
  4821 
  4822 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4823 now expressed as a proper nested rule (old-style tactic scripts may
  4824 require atomize_strip_tac to cope with non-atomic premises);
  4825 
  4826 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4827 to "split_conv" (old name still available for compatibility);
  4828 
  4829 * HOL: improved concrete syntax for strings (e.g. allows translation
  4830 rules with string literals);
  4831 
  4832 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4833  and Fleuriot's mechanization of analysis, including the transcendental
  4834  functions for the reals;
  4835 
  4836 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4837 
  4838 
  4839 *** CTT ***
  4840 
  4841 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4842 "lam" is displayed as TWO lambda-symbols
  4843 
  4844 * CTT: theory Main now available, containing everything (that is, Bool
  4845 and Arith);
  4846 
  4847 
  4848 *** General ***
  4849 
  4850 * Pure: the Simplifier has been implemented properly as a derived rule
  4851 outside of the actual kernel (at last!); the overall performance
  4852 penalty in practical applications is about 50%, while reliability of
  4853 the Isabelle inference kernel has been greatly improved;
  4854 
  4855 * print modes "brackets" and "no_brackets" control output of nested =>
  4856 (types) and ==> (props); the default behaviour is "brackets";
  4857 
  4858 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4859 as assumptions as well;
  4860 
  4861 * system: support Poly/ML 4.0;
  4862 
  4863 * system: isatool install handles KDE version 1 or 2;
  4864 
  4865 
  4866 
  4867 New in Isabelle99-1 (October 2000)
  4868 ----------------------------------
  4869 
  4870 *** Overview of INCOMPATIBILITIES ***
  4871 
  4872 * HOL: simplification of natural numbers is much changed; to partly
  4873 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4874 issue the following ML commands:
  4875 
  4876   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4877   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4878 
  4879 * HOL: simplification no longer dives into case-expressions; this is
  4880 controlled by "t.weak_case_cong" for each datatype t;
  4881 
  4882 * HOL: nat_less_induct renamed to less_induct;
  4883 
  4884 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4885 fixsome to patch .thy and .ML sources automatically;
  4886 
  4887   select_equality  -> some_equality
  4888   select_eq_Ex     -> some_eq_ex
  4889   selectI2EX       -> someI2_ex
  4890   selectI2         -> someI2
  4891   selectI          -> someI
  4892   select1_equality -> some1_equality
  4893   Eps_sym_eq       -> some_sym_eq_trivial
  4894   Eps_eq           -> some_eq_trivial
  4895 
  4896 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4897 
  4898 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4899 instead);
  4900 
  4901 * HOL: the recursion equations generated by 'recdef' are now called
  4902 f.simps instead of f.rules;
  4903 
  4904 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4905 
  4906 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4907 sometimes be needed;
  4908 
  4909 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4910 
  4911 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4912 
  4913 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4914 product is now "<*>" instead of "Times"; the lexicographic product is
  4915 now "<*lex*>" instead of "**";
  4916 
  4917 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4918 of main HOL, but was unused); better use HOL's datatype package;
  4919 
  4920 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4921 the old syntax may be recovered as follows:
  4922 
  4923   syntax (symbols)
  4924     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4925       (infixl "\\<oplus>" 100)
  4926 
  4927 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4928 
  4929 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4930 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4931 internally;
  4932 
  4933 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4934 changed from A/r to A//r;
  4935 
  4936 * ZF: new treatment of arithmetic (nat & int) may break some old
  4937 proofs;
  4938 
  4939 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4940 rulify -> rule_format, elimify -> elim_format, ...);
  4941 
  4942 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4943 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4944 should have to change intro!! to intro? only); replaced "delrule" by
  4945 "rule del";
  4946 
  4947 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4948 
  4949 * Provers: strengthened force_tac by using new first_best_tac;
  4950 
  4951 * LaTeX document preparation: several changes of isabelle.sty (see
  4952 lib/texinputs);
  4953 
  4954 
  4955 *** Document preparation ***
  4956 
  4957 * formal comments (text blocks etc.) in new-style theories may now
  4958 contain antiquotations of thm/prop/term/typ/text to be presented
  4959 according to latex print mode; concrete syntax is like this:
  4960 @{term[show_types] "f(x) = a + x"};
  4961 
  4962 * isatool mkdir provides easy setup of Isabelle session directories,
  4963 including proper document sources;
  4964 
  4965 * generated LaTeX sources are now deleted after successful run
  4966 (isatool document -c); may retain a copy somewhere else via -D option
  4967 of isatool usedir;
  4968 
  4969 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4970 style files, achieving self-contained LaTeX sources and simplifying
  4971 LaTeX debugging;
  4972 
  4973 * old-style theories now produce (crude) LaTeX output as well;
  4974 
  4975 * browser info session directories are now self-contained (may be put
  4976 on WWW server seperately); improved graphs of nested sessions; removed
  4977 graph for 'all sessions';
  4978 
  4979 * several improvements in isabelle style files; \isabellestyle{it}
  4980 produces fake math mode output; \isamarkupheader is now \section by
  4981 default; see lib/texinputs/isabelle.sty etc.;
  4982 
  4983 
  4984 *** Isar ***
  4985 
  4986 * Isar/Pure: local results and corresponding term bindings are now
  4987 subject to Hindley-Milner polymorphism (similar to ML); this
  4988 accommodates incremental type-inference very nicely;
  4989 
  4990 * Isar/Pure: new derived language element 'obtain' supports
  4991 generalized existence reasoning;
  4992 
  4993 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4994 support accumulation of results, without applying any rules yet;
  4995 useful to collect intermediate results without explicit name
  4996 references, and for use with transitivity rules with more than 2
  4997 premises;
  4998 
  4999 * Isar/Pure: scalable support for case-analysis type proofs: new
  5000 'case' language element refers to local contexts symbolically, as
  5001 produced by certain proof methods; internally, case names are attached
  5002 to theorems as "tags";
  5003 
  5004 * Isar/Pure: theory command 'hide' removes declarations from
  5005 class/type/const name spaces;
  5006 
  5007 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5008 indicate potential overloading;
  5009 
  5010 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5011 
  5012 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5013 "{a,b,c}" instead of {a,b,c};
  5014 
  5015 * Isar/Pure now provides its own version of intro/elim/dest
  5016 attributes; useful for building new logics, but beware of confusion
  5017 with the version in Provers/classical;
  5018 
  5019 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5020 case name 'antecedent';
  5021 
  5022 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5023 to the current context is now done automatically);
  5024 
  5025 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5026 for definining proof methods in ML;
  5027 
  5028 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5029 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5030 most cases, one should have to change intro!! to intro? only);
  5031 replaced "delrule" by "rule del";
  5032 
  5033 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5034 'symmetric' attribute (the latter supercedes [RS sym]);
  5035 
  5036 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5037 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5038 well (including splits);
  5039 
  5040 * Isar/Provers: Simplifier and Classical methods now support all kind
  5041 of modifiers used in the past, including 'cong', 'iff', etc.
  5042 
  5043 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5044 of Simplifier and Classical reasoner);
  5045 
  5046 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5047 now support named cases; major packages (inductive, datatype, primrec,
  5048 recdef) support case names and properly name parameters;
  5049 
  5050 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5051 monotonicity conditions are extracted to be proven at end of
  5052 calculations;
  5053 
  5054 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5055 method anyway;
  5056 
  5057 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5058 split_if split_if_asm; datatype package provides theorems foo.splits =
  5059 foo.split foo.split_asm for each datatype;
  5060 
  5061 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5062 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5063 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5064 use "(cases (simplified))" method in proper proof texts);
  5065 
  5066 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5067 
  5068 * Isar: names of theorems etc. may be natural numbers as well;
  5069 
  5070 * Isar: 'pr' command: optional arguments for goals_limit and
  5071 ProofContext.prems_limit; no longer prints theory contexts, but only
  5072 proof states;
  5073 
  5074 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5075 additional print modes to be specified; e.g. "pr(latex)" will print
  5076 proof state according to the Isabelle LaTeX style;
  5077 
  5078 * Isar: improved support for emulating tactic scripts, including proof
  5079 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5080 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5081 (for HOL datatypes);
  5082 
  5083 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5084 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5085 'proof method scripts' have to be in depth-first order;
  5086 
  5087 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5088 
  5089 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5090 should instead use individual commands for printing items
  5091 (print_commands, print_methods etc.);
  5092 
  5093 * Isar: added 'nothing' --- the empty list of theorems;
  5094 
  5095 
  5096 *** HOL ***
  5097 
  5098 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5099 corresponding virtual machine and a specification of its bytecode
  5100 verifier and a lightweight bytecode verifier, including proofs of
  5101 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5102 Cornelia Pusch (see also the homepage of project Bali at
  5103 http://isabelle.in.tum.de/Bali/);
  5104 
  5105 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5106 Clemens Ballarin;
  5107 
  5108 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5109 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5110 Rasmussen;
  5111 
  5112 * HOL/Lattice: fundamental concepts of lattice theory and order
  5113 structures, including duals, properties of bounds versus algebraic
  5114 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5115 Theorem for complete lattices etc.; may also serve as a demonstration
  5116 for abstract algebraic reasoning using axiomatic type classes, and
  5117 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5118 
  5119 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5120 von Oheimb;
  5121 
  5122 * HOL/IMPP: extension of IMP with local variables and mutually
  5123 recursive procedures, by David von Oheimb;
  5124 
  5125 * HOL/Lambda: converted into new-style theory and document;
  5126 
  5127 * HOL/ex/Multiquote: example of multiple nested quotations and
  5128 anti-quotations -- basically a generalized version of de-Bruijn
  5129 representation; very useful in avoiding lifting of operations;
  5130 
  5131 * HOL/record: added general record equality rule to simpset; fixed
  5132 select-update simplification procedure to handle extended records as
  5133 well; admit "r" as field name;
  5134 
  5135 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5136 other numeric types and also as the identity of groups, rings, etc.;
  5137 
  5138 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5139 Types nat and int belong to this axclass;
  5140 
  5141 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5142    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5143    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5144   two terms #m*u and #n*u are replaced by #(m+n)*u
  5145     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5146   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5147     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5148 
  5149 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5150 powerful prover for predicate logic but knows nothing of clasets; see
  5151 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5152 
  5153 * HOL: new version of "case_tac" subsumes both boolean case split and
  5154 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5155 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5156 
  5157 * HOL: simplification no longer dives into case-expressions: only the
  5158 selector expression is simplified, but not the remaining arms; to
  5159 enable full simplification of case-expressions for datatype t, you may
  5160 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5161 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5162 
  5163 * HOL/recdef: the recursion equations generated by 'recdef' for
  5164 function 'f' are now called f.simps instead of f.rules; if all
  5165 termination conditions are proved automatically, these simplification
  5166 rules are added to the simpset, as in primrec; rules may be named
  5167 individually as well, resulting in a separate list of theorems for
  5168 each equation;
  5169 
  5170 * HOL/While is a new theory that provides a while-combinator. It
  5171 permits the definition of tail-recursive functions without the
  5172 provision of a termination measure. The latter is necessary once the
  5173 invariant proof rule for while is applied.
  5174 
  5175 * HOL: new (overloaded) notation for the set of elements below/above
  5176 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5177 
  5178 * HOL: theorems impI, allI, ballI bound as "strip";
  5179 
  5180 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5181 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5182 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5183 
  5184 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5185 
  5186 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5187 main HOL, but was unused);
  5188 
  5189 * HOL: fewer consts declared as global (e.g. have to refer to
  5190 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5191 
  5192 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5193 in case of overlap with user translations (e.g. judgements over
  5194 tuples); (note that the underlying logical represenation is still
  5195 bogus);
  5196 
  5197 
  5198 *** ZF ***
  5199 
  5200 * ZF: simplification automatically cancels common terms in arithmetic
  5201 expressions over nat and int;
  5202 
  5203 * ZF: new treatment of nat to minimize type-checking: all operators
  5204 coerce their operands to a natural number using the function natify,
  5205 making the algebraic laws unconditional;
  5206 
  5207 * ZF: as above, for int: operators coerce their operands to an integer
  5208 using the function intify;
  5209 
  5210 * ZF: the integer library now contains many of the usual laws for the
  5211 orderings, including $<=, and monotonicity laws for $+ and $*;
  5212 
  5213 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5214 simplification;
  5215 
  5216 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5217 to the simplifier and classical reasoner simultaneously;
  5218 
  5219 
  5220 *** General ***
  5221 
  5222 * Provers: blast_tac now handles actual object-logic rules as
  5223 assumptions; note that auto_tac uses blast_tac internally as well;
  5224 
  5225 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5226 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5227 
  5228 * Provers: delrules now handles destruct rules as well (no longer need
  5229 explicit make_elim);
  5230 
  5231 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5232   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5233 use instead the strong form,
  5234   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5235 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5236 from destruct-rules;
  5237 
  5238 * Provers: Simplifier.easy_setup provides a fast path to basic
  5239 Simplifier setup for new object-logics;
  5240 
  5241 * Pure: AST translation rules no longer require constant head on LHS;
  5242 
  5243 * Pure: improved name spaces: ambiguous output is qualified; support
  5244 for hiding of names;
  5245 
  5246 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5247 XSYMBOL_HOME; no longer need to do manual configuration in most
  5248 situations;
  5249 
  5250 * system: compression of ML heaps images may now be controlled via -c
  5251 option of isabelle and isatool usedir (currently only observed by
  5252 Poly/ML);
  5253 
  5254 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5255 useful for remote X11);
  5256 
  5257 * system: provide TAGS file for Isabelle sources;
  5258 
  5259 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5260 order;
  5261 
  5262 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5263 timing flag supersedes proof_timing and Toplevel.trace;
  5264 
  5265 * ML: new combinators |>> and |>>> for incremental transformations
  5266 with secondary results (e.g. certain theory extensions):
  5267 
  5268 * ML: PureThy.add_defs gets additional argument to indicate potential
  5269 overloading (usually false);
  5270 
  5271 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5272 results;
  5273 
  5274 
  5275 
  5276 New in Isabelle99 (October 1999)
  5277 --------------------------------
  5278 
  5279 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5280 
  5281 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5282 are no longer simplified.  (This allows the simplifier to unfold recursive
  5283 functional programs.)  To restore the old behaviour, declare
  5284 
  5285     Delcongs [if_weak_cong];
  5286 
  5287 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5288 complement;
  5289 
  5290 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5291 
  5292 * HOL/datatype: mutual_induct_tac no longer exists --
  5293   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5294 
  5295 * HOL/typedef: fixed type inference for representing set; type
  5296 arguments now have to occur explicitly on the rhs as type constraints;
  5297 
  5298 * ZF: The con_defs part of an inductive definition may no longer refer
  5299 to constants declared in the same theory;
  5300 
  5301 * HOL, ZF: the function mk_cases, generated by the inductive
  5302 definition package, has lost an argument.  To simplify its result, it
  5303 uses the default simpset instead of a supplied list of theorems.
  5304 
  5305 * HOL/List: the constructors of type list are now Nil and Cons;
  5306 
  5307 * Simplifier: the type of the infix ML functions
  5308         setSSolver addSSolver setSolver addSolver
  5309 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5310 for packaging solvers. A solver is created via
  5311         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5312 where the string argument is only a comment.
  5313 
  5314 
  5315 *** Proof tools ***
  5316 
  5317 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5318 decision procedure for linear arithmetic. Currently it is used for
  5319 types `nat', `int', and `real' in HOL (see below); it can, should and
  5320 will be instantiated for other types and logics as well.
  5321 
  5322 * The simplifier now accepts rewrite rules with flexible heads, eg
  5323      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5324   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5325   matching.
  5326 
  5327 
  5328 *** General ***
  5329 
  5330 * New Isabelle/Isar subsystem provides an alternative to traditional
  5331 tactical theorem proving; together with the ProofGeneral/isar user
  5332 interface it offers an interactive environment for developing human
  5333 readable proof documents (Isar == Intelligible semi-automated
  5334 reasoning); for further information see isatool doc isar-ref,
  5335 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5336 
  5337 * improved and simplified presentation of theories: better HTML markup
  5338 (including colors), graph views in several sizes; isatool usedir now
  5339 provides a proper interface for user theories (via -P option); actual
  5340 document preparation based on (PDF)LaTeX is available as well (for
  5341 new-style theories only); see isatool doc system for more information;
  5342 
  5343 * native support for Proof General, both for classic Isabelle and
  5344 Isabelle/Isar;
  5345 
  5346 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5347 using the graph browser tool;
  5348 
  5349 * Isabelle manuals now also available as PDF;
  5350 
  5351 * theory loader rewritten from scratch (may not be fully
  5352 bug-compatible); old loadpath variable has been replaced by show_path,
  5353 add_path, del_path, reset_path functions; new operations such as
  5354 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5355 isatool doc ref);
  5356 
  5357 * improved isatool install: option -k creates KDE application icon,
  5358 option -p DIR installs standalone binaries;
  5359 
  5360 * added ML_PLATFORM setting (useful for cross-platform installations);
  5361 more robust handling of platform specific ML images for SML/NJ;
  5362 
  5363 * the settings environment is now statically scoped, i.e. it is never
  5364 created again in sub-processes invoked from isabelle, isatool, or
  5365 Isabelle;
  5366 
  5367 * path element specification '~~' refers to '$ISABELLE_HOME';
  5368 
  5369 * in locales, the "assumes" and "defines" parts may be omitted if
  5370 empty;
  5371 
  5372 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5373 long arrows);
  5374 
  5375 * new print_mode "HTML";
  5376 
  5377 * new flag show_tags controls display of tags of theorems (which are
  5378 basically just comments that may be attached by some tools);
  5379 
  5380 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5381 mode and goal output format:
  5382 
  5383 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5384 244c244
  5385 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5386 ---
  5387 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5388 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5389 181c181
  5390 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5391 ---
  5392 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5393 
  5394 * function bind_thms stores lists of theorems (cf. bind_thm);
  5395 
  5396 * new shorthand tactics ftac, eatac, datac, fatac;
  5397 
  5398 * qed (and friends) now accept "" as result name; in that case the
  5399 theorem is not stored, but proper checks and presentation of the
  5400 result still apply;
  5401 
  5402 * theorem database now also indexes constants "Trueprop", "all",
  5403 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5404 
  5405 
  5406 *** HOL ***
  5407 
  5408 ** HOL arithmetic **
  5409 
  5410 * There are now decision procedures for linear arithmetic over nat and
  5411 int:
  5412 
  5413 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5414 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5415 are treated as atomic; subformulae not involving type `nat' or `int'
  5416 are ignored; quantified subformulae are ignored unless they are
  5417 positive universal or negative existential. The tactic has to be
  5418 invoked by hand and can be a little bit slow. In particular, the
  5419 running time is exponential in the number of occurrences of `min' and
  5420 `max', and `-' on `nat'.
  5421 
  5422 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5423 (negated) (in)equalities among the premises and the conclusion into
  5424 account (i.e. no compound formulae) and does not know about `min' and
  5425 `max', and `-' on `nat'. It is fast and is used automatically by the
  5426 simplifier.
  5427 
  5428 NB: At the moment, these decision procedures do not cope with mixed
  5429 nat/int formulae where the two parts interact, such as `m < n ==>
  5430 int(m) < int(n)'.
  5431 
  5432 * HOL/Numeral provides a generic theory of numerals (encoded
  5433 efficiently as bit strings); setup for types nat/int/real is in place;
  5434 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5435 int, existing theories and proof scripts may require a few additional
  5436 type constraints;
  5437 
  5438 * integer division and remainder can now be performed on constant
  5439 arguments;
  5440 
  5441 * many properties of integer multiplication, division and remainder
  5442 are now available;
  5443 
  5444 * An interface to the Stanford Validity Checker (SVC) is available through the
  5445 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5446 are proved automatically.  SVC must be installed separately, and its results
  5447 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5448 invocation of the underlying oracle).  For SVC see
  5449   http://verify.stanford.edu/SVC
  5450 
  5451 * IsaMakefile: the HOL-Real target now builds an actual image;
  5452 
  5453 
  5454 ** HOL misc **
  5455 
  5456 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5457 (in Isabelle/Isar) -- by Gertrud Bauer;
  5458 
  5459 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5460 analysis for assembly languages with subtypes;
  5461 
  5462 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5463 -- avoids syntactic ambiguities and treats state, transition, and
  5464 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5465 changed syntax and (many) tactics;
  5466 
  5467 * HOL/inductive: Now also handles more general introduction rules such
  5468   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5469   theorems are now maintained within the theory (maintained via the
  5470   "mono" attribute);
  5471 
  5472 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5473   (using function types) such as
  5474 
  5475   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5476 
  5477 * HOL/record: record_simproc (part of the default simpset) takes care
  5478 of selectors applied to updated records; record_split_tac is no longer
  5479 part of the default claset; update_defs may now be removed from the
  5480 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5481 
  5482   claset_ref () := claset() addSWrapper record_split_wrapper;
  5483   Delsimprocs [record_simproc]
  5484 
  5485 * HOL/typedef: fixed type inference for representing set; type
  5486 arguments now have to occur explicitly on the rhs as type constraints;
  5487 
  5488 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5489 names rather than an ML expression;
  5490 
  5491 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5492 supplied later.  Program schemes can be defined, such as
  5493     "While B C s = (if B s then While B C (C s) else s)"
  5494 where the well-founded relation can be chosen after B and C have been given.
  5495 
  5496 * HOL/List: the constructors of type list are now Nil and Cons;
  5497 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5498 course, ML tools referring to List.list.op # etc. have to be adapted;
  5499 
  5500 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5501 disabled by default; run isabelle with option -m HOL to get back to
  5502 the original Gordon/HOL-style output;
  5503 
  5504 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5505 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5506 
  5507 * HOL basic syntax simplified (more orthogonal): all variants of
  5508 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5509 Eps operator is provided as well: "SOME x. P[x]";
  5510 
  5511 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5512 
  5513 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5514 thus available for user theories;
  5515 
  5516 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5517 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5518 time;
  5519 
  5520 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5521 several times and then mp;
  5522 
  5523 
  5524 *** LK ***
  5525 
  5526 * the notation <<...>> is now available as a notation for sequences of
  5527 formulas;
  5528 
  5529 * the simplifier is now installed
  5530 
  5531 * the axiom system has been generalized (thanks to Soren Heilmann)
  5532 
  5533 * the classical reasoner now has a default rule database
  5534 
  5535 
  5536 *** ZF ***
  5537 
  5538 * new primrec section allows primitive recursive functions to be given
  5539 directly (as in HOL) over datatypes and the natural numbers;
  5540 
  5541 * new tactics induct_tac and exhaust_tac for induction (or case
  5542 analysis) over datatypes and the natural numbers;
  5543 
  5544 * the datatype declaration of type T now defines the recursor T_rec;
  5545 
  5546 * simplification automatically does freeness reasoning for datatype
  5547 constructors;
  5548 
  5549 * automatic type-inference, with AddTCs command to insert new
  5550 type-checking rules;
  5551 
  5552 * datatype introduction rules are now added as Safe Introduction rules
  5553 to the claset;
  5554 
  5555 * the syntax "if P then x else y" is now available in addition to
  5556 if(P,x,y);
  5557 
  5558 
  5559 *** Internal programming interfaces ***
  5560 
  5561 * tuned simplifier trace output; new flag debug_simp;
  5562 
  5563 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5564 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5565 
  5566 * AxClass.axclass_tac lost the theory argument;
  5567 
  5568 * tuned current_goals_markers semantics: begin / end goal avoids
  5569 printing empty lines;
  5570 
  5571 * removed prs and prs_fn hook, which was broken because it did not
  5572 include \n in its semantics, forcing writeln to add one
  5573 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5574 string -> unit if you really want to output text without newline;
  5575 
  5576 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5577 plain output, interface builders may have to enable 'isabelle_font'
  5578 mode to get Isabelle font glyphs as before;
  5579 
  5580 * refined token_translation interface; INCOMPATIBILITY: output length
  5581 now of type real instead of int;
  5582 
  5583 * theory loader actions may be traced via new ThyInfo.add_hook
  5584 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5585 your own database of information attached to *whole* theories -- as
  5586 opposed to intra-theory data slots offered via TheoryDataFun;
  5587 
  5588 * proper handling of dangling sort hypotheses (at last!);
  5589 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5590 extra sort hypotheses that can be witnessed from the type signature;
  5591 the force_strip_shyps flag is gone, any remaining shyps are simply
  5592 left in the theorem (with a warning issued by strip_shyps_warning);
  5593 
  5594 
  5595 
  5596 New in Isabelle98-1 (October 1998)
  5597 ----------------------------------
  5598 
  5599 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5600 
  5601 * several changes of automated proof tools;
  5602 
  5603 * HOL: major changes to the inductive and datatype packages, including
  5604 some minor incompatibilities of theory syntax;
  5605 
  5606 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5607 called `inj_on';
  5608 
  5609 * HOL: removed duplicate thms in Arith:
  5610   less_imp_add_less  should be replaced by  trans_less_add1
  5611   le_imp_add_le      should be replaced by  trans_le_add1
  5612 
  5613 * HOL: unary minus is now overloaded (new type constraints may be
  5614 required);
  5615 
  5616 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5617 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5618 now taken as an integer constant.
  5619 
  5620 * Pure: ML function 'theory_of' renamed to 'theory';
  5621 
  5622 
  5623 *** Proof tools ***
  5624 
  5625 * Simplifier:
  5626   1. Asm_full_simp_tac is now more aggressive.
  5627      1. It will sometimes reorient premises if that increases their power to
  5628         simplify.
  5629      2. It does no longer proceed strictly from left to right but may also
  5630         rotate premises to achieve further simplification.
  5631      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5632      old Asm_full_simp_tac in that it does not rotate premises.
  5633   2. The simplifier now knows a little bit about nat-arithmetic.
  5634 
  5635 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5636 allows for selected deletion of wrappers, by introduction of names for
  5637 wrapper functionals.  This implies that addbefore, addSbefore,
  5638 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5639 and that adding two tactics with the same name overwrites the first
  5640 one (emitting a warning).
  5641   type wrapper = (int -> tactic) -> (int -> tactic)
  5642   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5643   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5644   delWrapper, delSWrapper: claset *  string            -> claset
  5645   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5646 
  5647 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5648 semantics; addbefore now affects only the unsafe part of step_tac
  5649 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5650 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5651 by Force_tac;
  5652 
  5653 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5654 compWrapper; added safe wrapper (and access functions for it);
  5655 
  5656 * HOL/split_all_tac is now much faster and fails if there is nothing
  5657 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5658 and the names of the automatically generated variables have changed.
  5659 split_all_tac has moved within claset() from unsafe wrappers to safe
  5660 wrappers, which means that !!-bound variables are split much more
  5661 aggressively, and safe_tac and clarify_tac now split such variables.
  5662 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5663 Note: the same holds for record_split_tac, which does the job of
  5664 split_all_tac for record fields.
  5665 
  5666 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5667 permanently to the default simpset using Addsplits just like
  5668 Addsimps. They can be removed via Delsplits just like
  5669 Delsimps. Lower-case versions are also available.
  5670 
  5671 * HOL/Simplifier: The rule split_if is now part of the default
  5672 simpset. This means that the simplifier will eliminate all occurrences
  5673 of if-then-else in the conclusion of a goal. To prevent this, you can
  5674 either remove split_if completely from the default simpset by
  5675 `Delsplits [split_if]' or remove it in a specific call of the
  5676 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5677 other case splitting rules to/from the default simpset: every datatype
  5678 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5679 t is the name of the datatype).
  5680 
  5681 * Classical reasoner / Simplifier combination: new force_tac (and
  5682 derivatives Force_tac, force) combines rewriting and classical
  5683 reasoning (and whatever other tools) similarly to auto_tac, but is
  5684 aimed to solve the given subgoal completely.
  5685 
  5686 
  5687 *** General ***
  5688 
  5689 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5690 and `goalw': the theory is no longer needed as an explicit argument -
  5691 the current theory context is used; assumptions are no longer returned
  5692 at the ML-level unless one of them starts with ==> or !!; it is
  5693 recommended to convert to these new commands using isatool fixgoal
  5694 (backup your sources first!);
  5695 
  5696 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5697 the current theory context, and 'theory' to lookup stored theories;
  5698 
  5699 * new theory section 'locale' for declaring constants, assumptions and
  5700 definitions that have local scope;
  5701 
  5702 * new theory section 'nonterminals' for purely syntactic types;
  5703 
  5704 * new theory section 'setup' for generic ML setup functions
  5705 (e.g. package initialization);
  5706 
  5707 * the distribution now includes Isabelle icons: see
  5708 lib/logo/isabelle-{small,tiny}.xpm;
  5709 
  5710 * isatool install - install binaries with absolute references to
  5711 ISABELLE_HOME/bin;
  5712 
  5713 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5714 
  5715 * print mode 'emacs' reserved for Isamode;
  5716 
  5717 * support multiple print (ast) translations per constant name;
  5718 
  5719 * theorems involving oracles are now printed with a suffixed [!];
  5720 
  5721 
  5722 *** HOL ***
  5723 
  5724 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5725 
  5726 * HOL/inductive package reorganized and improved: now supports mutual
  5727 definitions such as
  5728 
  5729   inductive EVEN ODD
  5730     intrs
  5731       null "0 : EVEN"
  5732       oddI "n : EVEN ==> Suc n : ODD"
  5733       evenI "n : ODD ==> Suc n : EVEN"
  5734 
  5735 new theorem list "elims" contains an elimination rule for each of the
  5736 recursive sets; inductive definitions now handle disjunctive premises
  5737 correctly (also ZF);
  5738 
  5739 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5740 "mutual_induct" no longer exists - the induction rule is always
  5741 contained in "induct";
  5742 
  5743 
  5744 * HOL/datatype package re-implemented and greatly improved: now
  5745 supports mutually recursive datatypes such as
  5746 
  5747   datatype
  5748     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5749             | SUM ('a aexp) ('a aexp)
  5750             | DIFF ('a aexp) ('a aexp)
  5751             | NUM 'a
  5752   and
  5753     'a bexp = LESS ('a aexp) ('a aexp)
  5754             | AND ('a bexp) ('a bexp)
  5755             | OR ('a bexp) ('a bexp)
  5756 
  5757 as well as indirectly recursive datatypes such as
  5758 
  5759   datatype
  5760     ('a, 'b) term = Var 'a
  5761                   | App 'b ((('a, 'b) term) list)
  5762 
  5763 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5764 induction on mutually / indirectly recursive datatypes.
  5765 
  5766 Primrec equations are now stored in theory and can be accessed via
  5767 <function_name>.simps.
  5768 
  5769 INCOMPATIBILITIES:
  5770 
  5771   - Theories using datatypes must now have theory Datatype as an
  5772     ancestor.
  5773   - The specific <typename>.induct_tac no longer exists - use the
  5774     generic induct_tac instead.
  5775   - natE has been renamed to nat.exhaust - use exhaust_tac
  5776     instead of res_inst_tac ... natE. Note that the variable
  5777     names in nat.exhaust differ from the names in natE, this
  5778     may cause some "fragile" proofs to fail.
  5779   - The theorems split_<typename>_case and split_<typename>_case_asm
  5780     have been renamed to <typename>.split and <typename>.split_asm.
  5781   - Since default sorts of type variables are now handled correctly,
  5782     some datatype definitions may have to be annotated with explicit
  5783     sort constraints.
  5784   - Primrec definitions no longer require function name and type
  5785     of recursive argument.
  5786 
  5787 Consider using isatool fixdatatype to adapt your theories and proof
  5788 scripts to the new package (backup your sources first!).
  5789 
  5790 
  5791 * HOL/record package: considerably improved implementation; now
  5792 includes concrete syntax for record types, terms, updates; theorems
  5793 for surjective pairing and splitting !!-bound record variables; proof
  5794 support is as follows:
  5795 
  5796   1) standard conversions (selectors or updates applied to record
  5797 constructor terms) are part of the standard simpset;
  5798 
  5799   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5800 made part of standard simpset and claset via addIffs;
  5801 
  5802   3) a tactic for record field splitting (record_split_tac) is part of
  5803 the standard claset (addSWrapper);
  5804 
  5805 To get a better idea about these rules you may retrieve them via
  5806 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5807 the name of your record type.
  5808 
  5809 The split tactic 3) conceptually simplifies by the following rule:
  5810 
  5811   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5812 
  5813 Thus any record variable that is bound by meta-all will automatically
  5814 blow up into some record constructor term, consequently the
  5815 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5816 solve record problems automatically.
  5817 
  5818 
  5819 * reorganized the main HOL image: HOL/Integ and String loaded by
  5820 default; theory Main includes everything;
  5821 
  5822 * automatic simplification of integer sums and comparisons, using cancellation;
  5823 
  5824 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5825 
  5826 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5827 
  5828 * many new identities for unions, intersections, set difference, etc.;
  5829 
  5830 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5831 called split_if, split_split, split_sum_case and split_nat_case (to go
  5832 with add/delsplits);
  5833 
  5834 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5835 (?x::unit) = (); this is made part of the default simpset, which COULD
  5836 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5837 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5838 unit_abs_eta_conv is added in order to counter the effect of
  5839 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5840 %u.f();
  5841 
  5842 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5843 makes more sense);
  5844 
  5845 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5846   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5847   disjointness reasoning but breaking a few old proofs.
  5848 
  5849 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5850 to 'converse' from 'inverse' (for compatibility with ZF and some
  5851 literature);
  5852 
  5853 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5854 the well-founded relation;
  5855 
  5856 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5857     Compl A.  The "Compl" syntax remains available as input syntax for this
  5858     release ONLY.
  5859 
  5860 * HOL/Update: new theory of function updates:
  5861     f(a:=b) == %x. if x=a then b else f x
  5862 may also be iterated as in f(a:=b,c:=d,...);
  5863 
  5864 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5865 
  5866 * HOL/List:
  5867   - new function list_update written xs[i:=v] that updates the i-th
  5868     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5869   - new function `upt' written [i..j(] which generates the list
  5870     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5871     bound write [i..j], which is a shorthand for [i..j+1(].
  5872   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5873 
  5874 * HOL/Arith:
  5875   - removed 'pred' (predecessor) function;
  5876   - generalized some theorems about n-1;
  5877   - many new laws about "div" and "mod";
  5878   - new laws about greatest common divisors (see theory ex/Primes);
  5879 
  5880 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5881 instead of "inverse";
  5882 
  5883 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5884   of the multiset ordering;
  5885 
  5886 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5887   (not included by default);
  5888 
  5889 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5890 
  5891 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5892   programs, i.e. different program variables may have different types.
  5893 
  5894 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5895   [previously, this check worked only if the rewrite rule was unconditional]
  5896   Now rew can involve either definitions or equalities (either == or =).
  5897 
  5898 
  5899 *** ZF ***
  5900 
  5901 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5902   only the theorems proved on ZF.ML;
  5903 
  5904 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5905   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5906   disjointness reasoning but breaking a few old proofs.
  5907 
  5908 * ZF/Update: new theory of function updates
  5909     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5910   may also be iterated as in f(a:=b,c:=d,...);
  5911 
  5912 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5913 
  5914 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5915   [previously, this check worked only if the rewrite rule was unconditional]
  5916   Now rew can involve either definitions or equalities (either == or =).
  5917 
  5918 * case_tac provided for compatibility with HOL
  5919     (like the old excluded_middle_tac, but with subgoals swapped)
  5920 
  5921 
  5922 *** Internal programming interfaces ***
  5923 
  5924 * Pure: several new basic modules made available for general use, see
  5925 also src/Pure/README;
  5926 
  5927 * improved the theory data mechanism to support encapsulation (data
  5928 kind name replaced by private Object.kind, acting as authorization
  5929 key); new type-safe user interface via functor TheoryDataFun; generic
  5930 print_data function becomes basically useless;
  5931 
  5932 * removed global_names compatibility flag -- all theory declarations
  5933 are qualified by default;
  5934 
  5935 * module Pure/Syntax now offers quote / antiquote translation
  5936 functions (useful for Hoare logic etc. with implicit dependencies);
  5937 see HOL/ex/Antiquote for an example use;
  5938 
  5939 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5940 cterm -> thm;
  5941 
  5942 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5943 subgoal;
  5944 
  5945 * Display.print_goals function moved to Locale.print_goals;
  5946 
  5947 * standard print function for goals supports current_goals_markers
  5948 variable for marking begin of proof, end of proof, start of goal; the
  5949 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5950 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5951 for example;
  5952 
  5953 
  5954 
  5955 New in Isabelle98 (January 1998)
  5956 --------------------------------
  5957 
  5958 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5959 
  5960 * changed lexical syntax of terms / types: dots made part of long
  5961 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5962 
  5963 * simpset (and claset) reference variable replaced by functions
  5964 simpset / simpset_ref;
  5965 
  5966 * no longer supports theory aliases (via merge) and non-trivial
  5967 implicit merge of thms' signatures;
  5968 
  5969 * most internal names of constants changed due to qualified names;
  5970 
  5971 * changed Pure/Sequence interface (see Pure/seq.ML);
  5972 
  5973 
  5974 *** General Changes ***
  5975 
  5976 * hierachically structured name spaces (for consts, types, axms, thms
  5977 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5978 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5979 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5980 long_names for fully qualified output names; NOTE: ML programs
  5981 (special tactics, packages etc.) referring to internal names may have
  5982 to be adapted to cope with fully qualified names; in case of severe
  5983 backward campatibility problems try setting 'global_names' at compile
  5984 time to have enrything declared within a flat name space; one may also
  5985 fine tune name declarations in theories via the 'global' and 'local'
  5986 section;
  5987 
  5988 * reimplemented the implicit simpset and claset using the new anytype
  5989 data filed in signatures; references simpset:simpset ref etc. are
  5990 replaced by functions simpset:unit->simpset and
  5991 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5992 to patch your ML files accordingly;
  5993 
  5994 * HTML output now includes theory graph data for display with Java
  5995 applet or isatool browser; data generated automatically via isatool
  5996 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5997 
  5998 * defs may now be conditional; improved rewrite_goals_tac to handle
  5999 conditional equations;
  6000 
  6001 * defs now admits additional type arguments, using TYPE('a) syntax;
  6002 
  6003 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6004 creates a new theory node; implicit merge of thms' signatures is
  6005 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6006 transfer:theory->thm->thm in (rare) cases;
  6007 
  6008 * improved handling of draft signatures / theories; draft thms (and
  6009 ctyps, cterms) are automatically promoted to real ones;
  6010 
  6011 * slightly changed interfaces for oracles: admit many per theory, named
  6012 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6013 
  6014 * print_goals: optional output of const types (set show_consts and
  6015 show_types);
  6016 
  6017 * improved output of warnings (###) and errors (***);
  6018 
  6019 * subgoal_tac displays a warning if the new subgoal has type variables;
  6020 
  6021 * removed old README and Makefiles;
  6022 
  6023 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6024 
  6025 * removed obsolete init_pps and init_database;
  6026 
  6027 * deleted the obsolete tactical STATE, which was declared by
  6028     fun STATE tacfun st = tacfun st st;
  6029 
  6030 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6031 (which abbreviates $HOME);
  6032 
  6033 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6034 use isatool fixseq to adapt your ML programs (this works for fully
  6035 qualified references to the Sequence structure only!);
  6036 
  6037 * use_thy no longer requires writable current directory; it always
  6038 reloads .ML *and* .thy file, if either one is out of date;
  6039 
  6040 
  6041 *** Classical Reasoner ***
  6042 
  6043 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6044 tactics that use classical reasoning to simplify a subgoal without
  6045 splitting it into several subgoals;
  6046 
  6047 * Safe_tac: like safe_tac but uses the default claset;
  6048 
  6049 
  6050 *** Simplifier ***
  6051 
  6052 * added simplification meta rules:
  6053     (asm_)(full_)simplify: simpset -> thm -> thm;
  6054 
  6055 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6056 logics (again);
  6057 
  6058 * added prems argument to simplification procedures;
  6059 
  6060 * HOL, FOL, ZF: added infix function `addsplits':
  6061   instead of `<simpset> setloop (split_tac <thms>)'
  6062   you can simply write `<simpset> addsplits <thms>'
  6063 
  6064 
  6065 *** Syntax ***
  6066 
  6067 * TYPE('a) syntax for type reflection terms;
  6068 
  6069 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6070 
  6071 * pretty printer: changed order of mixfix annotation preference (again!);
  6072 
  6073 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6074 
  6075 
  6076 *** HOL ***
  6077 
  6078 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6079   with `addloop' of the simplifier to faciliate case splitting in premises.
  6080 
  6081 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6082 
  6083 * HOL/Auth: new protocol proofs including some for the Internet
  6084   protocol TLS;
  6085 
  6086 * HOL/Map: new theory of `maps' a la VDM;
  6087 
  6088 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6089 cancelling out common nat summands from =, <, <= (in)equalities, or
  6090 differences; simplification procedures nat_cancel_factor for
  6091 cancelling common factor from =, <, <= (in)equalities over natural
  6092 sums; nat_cancel contains both kinds of procedures, it is installed by
  6093 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6094 
  6095 * HOL/simplifier: terms of the form
  6096   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6097   are rewritten to
  6098   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6099   and those of the form
  6100   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6101   are rewritten to
  6102   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6103 
  6104 * HOL/datatype
  6105   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6106 
  6107   P(t_case f1 ... fn x) =
  6108      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6109         ...
  6110        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6111      )
  6112 
  6113   and a theorem `split_t_case_asm' of the form
  6114 
  6115   P(t_case f1 ... fn x) =
  6116     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6117         ...
  6118        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6119      )
  6120   which can be added to a simpset via `addsplits'. The existing theorems
  6121   expand_list_case and expand_option_case have been renamed to
  6122   split_list_case and split_option_case.
  6123 
  6124 * HOL/Arithmetic:
  6125   - `pred n' is automatically converted to `n-1'.
  6126     Users are strongly encouraged not to use `pred' any longer,
  6127     because it will disappear altogether at some point.
  6128   - Users are strongly encouraged to write "0 < n" rather than
  6129     "n ~= 0". Theorems and proof tools have been modified towards this
  6130     `standard'.
  6131 
  6132 * HOL/Lists:
  6133   the function "set_of_list" has been renamed "set" (and its theorems too);
  6134   the function "nth" now takes its arguments in the reverse order and
  6135   has acquired the infix notation "!" as in "xs!n".
  6136 
  6137 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6138 
  6139 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6140   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6141 
  6142 * HOL/record: extensible records with schematic structural subtyping
  6143 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6144 still lacks various theorems and concrete record syntax;
  6145 
  6146 
  6147 *** HOLCF ***
  6148 
  6149 * removed "axioms" and "generated by" sections;
  6150 
  6151 * replaced "ops" section by extended "consts" section, which is capable of
  6152   handling the continuous function space "->" directly;
  6153 
  6154 * domain package:
  6155   . proves theorems immediately and stores them in the theory,
  6156   . creates hierachical name space,
  6157   . now uses normal mixfix annotations (instead of cinfix...),
  6158   . minor changes to some names and values (for consistency),
  6159   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6160   . separator between mutual domain defs: changed "," to "and",
  6161   . improved handling of sort constraints;  now they have to
  6162     appear on the left-hand side of the equations only;
  6163 
  6164 * fixed LAM <x,y,zs>.b syntax;
  6165 
  6166 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6167 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6168 
  6169 
  6170 *** FOL and ZF ***
  6171 
  6172 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6173   with `addloop' of the simplifier to faciliate case splitting in premises.
  6174 
  6175 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6176 in HOL, they strip ALL and --> from proved theorems;
  6177 
  6178 
  6179 
  6180 New in Isabelle94-8 (May 1997)
  6181 ------------------------------
  6182 
  6183 *** General Changes ***
  6184 
  6185 * new utilities to build / run / maintain Isabelle etc. (in parts
  6186 still somewhat experimental); old Makefiles etc. still functional;
  6187 
  6188 * new 'Isabelle System Manual';
  6189 
  6190 * INSTALL text, together with ./configure and ./build scripts;
  6191 
  6192 * reimplemented type inference for greater efficiency, better error
  6193 messages and clean internal interface;
  6194 
  6195 * prlim command for dealing with lots of subgoals (an easier way of
  6196 setting goals_limit);
  6197 
  6198 
  6199 *** Syntax ***
  6200 
  6201 * supports alternative (named) syntax tables (parser and pretty
  6202 printer); internal interface is provided by add_modesyntax(_i);
  6203 
  6204 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6205 be used in conjunction with the Isabelle symbol font; uses the
  6206 "symbols" syntax table;
  6207 
  6208 * added token_translation interface (may translate name tokens in
  6209 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6210 the current print_mode); IMPORTANT: user print translation functions
  6211 are responsible for marking newly introduced bounds
  6212 (Syntax.mark_boundT);
  6213 
  6214 * token translations for modes "xterm" and "xterm_color" that display
  6215 names in bold, underline etc. or colors (which requires a color
  6216 version of xterm);
  6217 
  6218 * infixes may now be declared with names independent of their syntax;
  6219 
  6220 * added typed_print_translation (like print_translation, but may
  6221 access type of constant);
  6222 
  6223 
  6224 *** Classical Reasoner ***
  6225 
  6226 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6227 some limitations.  Blast_tac...
  6228   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6229   + ignores elimination rules that don't have the correct format
  6230         (the conclusion MUST be a formula variable)
  6231   + ignores types, which can make HOL proofs fail
  6232   + rules must not require higher-order unification, e.g. apply_type in ZF
  6233     [message "Function Var's argument not a bound variable" relates to this]
  6234   + its proof strategy is more general but can actually be slower
  6235 
  6236 * substitution with equality assumptions no longer permutes other
  6237 assumptions;
  6238 
  6239 * minor changes in semantics of addafter (now called addaltern); renamed
  6240 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6241 (and access functions for it);
  6242 
  6243 * improved combination of classical reasoner and simplifier:
  6244   + functions for handling clasimpsets
  6245   + improvement of addss: now the simplifier is called _after_ the
  6246     safe steps.
  6247   + safe variant of addss called addSss: uses safe simplifications
  6248     _during_ the safe steps. It is more complete as it allows multiple
  6249     instantiations of unknowns (e.g. with slow_tac).
  6250 
  6251 *** Simplifier ***
  6252 
  6253 * added interface for simplification procedures (functions that
  6254 produce *proven* rewrite rules on the fly, depending on current