NEWS
author wenzelm
Wed Jul 22 11:23:09 2009 +0200 (2009-07-22)
changeset 32131 7913823f14e3
parent 32130 2a0645733185
parent 32092 6a5995438266
child 32136 672dfd59ff03
permissions -rw-r--r--
merged, resolving trivial conflict;
     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 * Code generator attributes follow the usual underscore convention:
    22     code_unfold     replaces    code unfold
    23     code_post       replaces    code post
    24     etc.
    25   INCOMPATIBILITY.
    26 
    27 * New quickcheck implementation using new code generator.
    28 
    29 * New type class boolean_algebra.
    30 
    31 * Refinements to lattices classes:
    32   - added boolean_algebra type class
    33   - less default intro/elim rules in locale variant, more default
    34     intro/elim rules in class variant: more uniformity
    35   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    36   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    37   - renamed ACI to inf_sup_aci
    38 
    39 * Class semiring_div requires superclass no_zero_divisors and proof of
    40 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    41 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    42 generalized to class semiring_div, subsuming former theorems
    43 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    44 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    45 INCOMPATIBILITY.
    46 
    47 * Power operations on relations and functions are now one dedicate
    48 constant compow with infix syntax "^^".  Power operations on
    49 multiplicative monoids retains syntax "^" and is now defined generic
    50 in class power.  INCOMPATIBILITY.
    51 
    52 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    53 infinite sets. It is shown that they form a complete lattice.
    54 
    55 * ML antiquotation @{code_datatype} inserts definition of a datatype
    56 generated by the code generator; see Predicate.thy for an example.
    57 
    58 * New method "linarith" invokes existing linear arithmetic decision
    59 procedure only.
    60 
    61 * Implementation of quickcheck using generic code generator; default
    62 generators are provided for all suitable HOL types, records and
    63 datatypes.
    64 
    65 * Constants Set.Pow and Set.image now with authentic syntax;
    66 object-logic definitions Set.Pow_def and Set.image_def.
    67 INCOMPATIBILITY.
    68 
    69 * Renamed theorems:
    70 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    71 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    72 Suc_plus1 -> Suc_eq_plus1
    73 
    74 * New sledgehammer option "Full Types" in Proof General settings menu.
    75 Causes full type information to be output to the ATPs.  This slows
    76 ATPs down considerably but eliminates a source of unsound "proofs"
    77 that fail later.
    78 
    79 * Discontinued ancient tradition to suffix certain ML module names
    80 with "_package", e.g.:
    81 
    82     DatatypePackage ~> Datatype
    83     InductivePackage ~> Inductive
    84 
    85     etc.
    86 
    87 INCOMPATIBILITY.
    88 
    89 * NewNumberTheory: Jeremy Avigad's new version of part of
    90 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
    91 
    92 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    93 
    94 * Abbreviation "arbitrary" of "undefined" has disappeared; use
    95 "undefined" directly.  INCOMPATIBILITY.
    96 
    97 * New evaluator "approximate" approximates an real valued term using
    98 the same method as the approximation method.
    99 
   100 * Method "approximate" supports now arithmetic expressions as
   101 boundaries of intervals and implements interval splitting and Taylor
   102 series expansion.
   103 
   104 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   105 the theorems in DERIV_intros assumes composition with an additional
   106 function and matches a variable to the derivative, which has to be
   107 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   108 the derivative of most elementary terms.
   109 
   110 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   111 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   112 
   113 
   114 *** ML ***
   115 
   116 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   117 functors have their own ML name space there is no point to mark them
   118 separately.)  Minor INCOMPATIBILITY.
   119 
   120 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   121 
   122 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   123 cominators for "args".  INCOMPATIBILITY, need to use simplified
   124 Attrib/Method.setup introduced in Isabelle2009.
   125 
   126 * Display.pretty_thm now requires a proper context (cf. former
   127 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   128 or even Display.pretty_thm_without_context as last resort.
   129 INCOMPATIBILITY.
   130 
   131 
   132 *** System ***
   133 
   134 * Discontinued support for Poly/ML 4.x versions.
   135 
   136 * Removed "compress" option from isabelle-process and isabelle usedir;
   137 this is always enabled.
   138 
   139 * More fine-grained control of proof parallelism, cf.
   140 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   141 
   142 
   143 
   144 New in Isabelle2009 (April 2009)
   145 --------------------------------
   146 
   147 *** General ***
   148 
   149 * Simplified main Isabelle executables, with less surprises on
   150 case-insensitive file-systems (such as Mac OS).
   151 
   152   - The main Isabelle tool wrapper is now called "isabelle" instead of
   153     "isatool."
   154 
   155   - The former "isabelle" alias for "isabelle-process" has been
   156     removed (should rarely occur to regular users).
   157 
   158   - The former "isabelle-interface" and its alias "Isabelle" have been
   159     removed (interfaces are now regular Isabelle tools).
   160 
   161 Within scripts and make files, the Isabelle environment variables
   162 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   163 respectively.  (The latter are still available as legacy feature.)
   164 
   165 The old isabelle-interface wrapper could react in confusing ways if
   166 the interface was uninstalled or changed otherwise.  Individual
   167 interface tool configuration is now more explicit, see also the
   168 Isabelle system manual.  In particular, Proof General is now available
   169 via "isabelle emacs".
   170 
   171 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   172 purge installed copies of Isabelle executables and re-run "isabelle
   173 install -p ...", or use symlinks.
   174 
   175 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   176 old ~/isabelle, which was slightly non-standard and apt to cause
   177 surprises on case-insensitive file-systems (such as Mac OS).
   178 
   179 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   180 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   181 care is required when using older releases of Isabelle.  Note that
   182 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   183 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   184 
   185 * Proofs of fully specified statements are run in parallel on
   186 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   187 a regular 4-core machine, if the initial heap space is made reasonably
   188 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   189 
   190 * The main reference manuals ("isar-ref", "implementation", and
   191 "system") have been updated and extended.  Formally checked references
   192 as hyperlinks are now available uniformly.
   193 
   194 
   195 *** Pure ***
   196 
   197 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   198 respects.  The most important changes are listed below.  See the
   199 Tutorial on Locales ("locales" manual) for details.
   200 
   201 - In locale expressions, instantiation replaces renaming.  Parameters
   202 must be declared in a for clause.  To aid compatibility with previous
   203 parameter inheritance, in locale declarations, parameters that are not
   204 'touched' (instantiation position "_" or omitted) are implicitly added
   205 with their syntax at the beginning of the for clause.
   206 
   207 - Syntax from abbreviations and definitions in locales is available in
   208 locale expressions and context elements.  The latter is particularly
   209 useful in locale declarations.
   210 
   211 - More flexible mechanisms to qualify names generated by locale
   212 expressions.  Qualifiers (prefixes) may be specified in locale
   213 expressions, and can be marked as mandatory (syntax: "name!:") or
   214 optional (syntax "name?:").  The default depends for plain "name:"
   215 depends on the situation where a locale expression is used: in
   216 commands 'locale' and 'sublocale' prefixes are optional, in
   217 'interpretation' and 'interpret' prefixes are mandatory.  The old
   218 implicit qualifiers derived from the parameter names of a locale are
   219 no longer generated.
   220 
   221 - Command "sublocale l < e" replaces "interpretation l < e".  The
   222 instantiation clause in "interpretation" and "interpret" (square
   223 brackets) is no longer available.  Use locale expressions.
   224 
   225 - When converting proof scripts, mandatory qualifiers in
   226 'interpretation' and 'interpret' should be retained by default, even
   227 if this is an INCOMPATIBILITY compared to former behavior.  In the
   228 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   229 in locale expressions range over a single locale instance only.
   230 
   231 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   232 In existing theorem specifications replace the includes element by the
   233 respective context elements of the included locale, omitting those
   234 that are already present in the theorem specification.  Multiple
   235 assume elements of a locale should be replaced by a single one
   236 involving the locale predicate.  In the proof body, declarations (most
   237 notably theorems) may be regained by interpreting the respective
   238 locales in the proof context as required (command "interpret").
   239 
   240 If using "includes" in replacement of a target solely because the
   241 parameter types in the theorem are not as general as in the target,
   242 consider declaring a new locale with additional type constraints on
   243 the parameters (context element "constrains").
   244 
   245 - Discontinued "locale (open)".  INCOMPATIBILITY.
   246 
   247 - Locale interpretation commands no longer attempt to simplify goal.
   248 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   249 methods intro_locales and unfold_locales to clarify.
   250 
   251 - Locale interpretation commands no longer accept interpretation
   252 attributes.  INCOMPATIBILITY.
   253 
   254 * Class declaration: so-called "base sort" must not be given in import
   255 list any longer, but is inferred from the specification.  Particularly
   256 in HOL, write
   257 
   258     class foo = ...
   259 
   260 instead of
   261 
   262     class foo = type + ...
   263 
   264 * Class target: global versions of theorems stemming do not carry a
   265 parameter prefix any longer.  INCOMPATIBILITY.
   266 
   267 * Class 'instance' command no longer accepts attached definitions.
   268 INCOMPATIBILITY, use proper 'instantiation' target instead.
   269 
   270 * Recovered hiding of consts, which was accidentally broken in
   271 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   272 makes c inaccessible; consider using ``hide (open) const c'' instead.
   273 
   274 * Slightly more coherent Pure syntax, with updated documentation in
   275 isar-ref manual.  Removed locales meta_term_syntax and
   276 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   277 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   278 directly in regular applications.
   279 
   280 * There is a new syntactic category "float_const" for signed decimal
   281 fractions (e.g. 123.45 or -123.45).
   282 
   283 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   284 interface with 'setup' command instead.
   285 
   286 * Command 'local_setup' is similar to 'setup', but operates on a local
   287 theory context.
   288 
   289 * The 'axiomatization' command now only works within a global theory
   290 context.  INCOMPATIBILITY.
   291 
   292 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   293 hypotheses.  Sorts required in the course of reasoning need to be
   294 covered by the constraints in the initial statement, completed by the
   295 type instance information of the background theory.  Non-trivial sort
   296 hypotheses, which rarely occur in practice, may be specified via
   297 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   298 
   299   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   300 
   301 The result contains an implicit sort hypotheses as before --
   302 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   303 normalization.
   304 
   305 * Generalized Isar history, with support for linear undo, direct state
   306 addressing etc.
   307 
   308 * Changed defaults for unify configuration options:
   309 
   310   unify_trace_bound = 50 (formerly 25)
   311   unify_search_bound = 60 (formerly 30)
   312 
   313 * Different bookkeeping for code equations (INCOMPATIBILITY):
   314 
   315   a) On theory merge, the last set of code equations for a particular
   316      constant is taken (in accordance with the policy applied by other
   317      parts of the code generator framework).
   318 
   319   b) Code equations stemming from explicit declarations (e.g. code
   320      attribute) gain priority over default code equations stemming
   321      from definition, primrec, fun etc.
   322 
   323 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   324 
   325 * Unified theorem tables for both code generators.  Thus [code
   326 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   327 
   328 * Command 'find_consts' searches for constants based on type and name
   329 patterns, e.g.
   330 
   331     find_consts "_ => bool"
   332 
   333 By default, matching is against subtypes, but it may be restricted to
   334 the whole type.  Searching by name is possible.  Multiple queries are
   335 conjunctive and queries may be negated by prefixing them with a
   336 hyphen:
   337 
   338     find_consts strict: "_ => bool" name: "Int" -"int => int"
   339 
   340 * New 'find_theorems' criterion "solves" matches theorems that
   341 directly solve the current goal (modulo higher-order unification).
   342 
   343 * Auto solve feature for main theorem statements: whenever a new goal
   344 is stated, "find_theorems solves" is called; any theorems that could
   345 solve the lemma directly are listed as part of the goal state.
   346 Cf. associated options in Proof General Isabelle settings menu,
   347 enabled by default, with reasonable timeout for pathological cases of
   348 higher-order unification.
   349 
   350 
   351 *** Document preparation ***
   352 
   353 * Antiquotation @{lemma} now imitates a regular terminal proof,
   354 demanding keyword 'by' and supporting the full method expression
   355 syntax just like the Isar command 'by'.
   356 
   357 
   358 *** HOL ***
   359 
   360 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   361 points Main and Complex_Main remain as before.
   362 
   363 * Logic image HOL-Plain provides a minimal HOL with the most important
   364 tools available (inductive, datatype, primrec, ...).  This facilitates
   365 experimentation and tool development.  Note that user applications
   366 (and library theories) should never refer to anything below theory
   367 Main, as before.
   368 
   369 * Logic image HOL-Main stops at theory Main, and thus facilitates
   370 experimentation due to shorter build times.
   371 
   372 * Logic image HOL-NSA contains theories of nonstandard analysis which
   373 were previously part of former HOL-Complex.  Entry point Hyperreal
   374 remains valid, but theories formerly using Complex_Main should now use
   375 new entry point Hypercomplex.
   376 
   377 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   378 Posix processes.  Avoids potentially expensive forking of the ML
   379 process.  New thread-based implementation also works on non-Unix
   380 platforms (Cygwin).  Provers are no longer hardwired, but defined
   381 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   382 commands are covered in the isar-ref manual.
   383 
   384 * Wrapper scripts for remote SystemOnTPTP service allows to use
   385 sledgehammer without local ATP installation (Vampire etc.). Other
   386 provers may be included via suitable ML wrappers, see also
   387 src/HOL/ATP_Linkup.thy.
   388 
   389 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   390 menu.
   391 
   392 * The metis method no longer fails because the theorem is too trivial
   393 (contains the empty clause).
   394 
   395 * The metis method now fails in the usual manner, rather than raising
   396 an exception, if it determines that it cannot prove the theorem.
   397 
   398 * Method "coherent" implements a prover for coherent logic (see also
   399 src/Tools/coherent.ML).
   400 
   401 * Constants "undefined" and "default" replace "arbitrary".  Usually
   402 "undefined" is the right choice to replace "arbitrary", though
   403 logically there is no difference.  INCOMPATIBILITY.
   404 
   405 * Command "value" now integrates different evaluation mechanisms.  The
   406 result of the first successful evaluation mechanism is printed.  In
   407 square brackets a particular named evaluation mechanisms may be
   408 specified (currently, [SML], [code] or [nbe]).  See further
   409 src/HOL/ex/Eval_Examples.thy.
   410 
   411 * Normalization by evaluation now allows non-leftlinear equations.
   412 Declare with attribute [code nbe].
   413 
   414 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   415 as the structured Isar versions "cases" and "induct", cf. the
   416 corresponding "cases" and "induct" attributes.  Mutual induction rules
   417 are now presented as a list of individual projections
   418 (e.g. foo_bar.inducts for types foo and bar); the old format with
   419 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   420 rare situations a different rule is selected --- notably nested tuple
   421 elimination instead of former prod.exhaust: use explicit (case_tac t
   422 rule: prod.exhaust) here.
   423 
   424 * Attributes "cases", "induct", "coinduct" support "del" option.
   425 
   426 * Removed fact "case_split_thm", which duplicates "case_split".
   427 
   428 * The option datatype has been moved to a new theory Option.  Renamed
   429 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   430 
   431 * New predicate "strict_mono" classifies strict functions on partial
   432 orders.  With strict functions on linear orders, reasoning about
   433 (in)equalities is facilitated by theorems "strict_mono_eq",
   434 "strict_mono_less_eq" and "strict_mono_less".
   435 
   436 * Some set operations are now proper qualified constants with
   437 authentic syntax.  INCOMPATIBILITY:
   438 
   439     op Int ~>   Set.Int
   440     op Un ~>    Set.Un
   441     INTER ~>    Set.INTER
   442     UNION ~>    Set.UNION
   443     Inter ~>    Set.Inter
   444     Union ~>    Set.Union
   445     {} ~>       Set.empty
   446     UNIV ~>     Set.UNIV
   447 
   448 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   449 theory Set.
   450 
   451 * Auxiliary class "itself" has disappeared -- classes without any
   452 parameter are treated as expected by the 'class' command.
   453 
   454 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   455 
   456 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   457 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   458 
   459 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   460 method "approximation".  It proves formulas on real values by using
   461 interval arithmetic.  In the formulas are also the transcendental
   462 functions sin, cos, tan, atan, ln, exp and the constant pi are
   463 allowed. For examples see
   464 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   465 
   466 * Theory "Reflection" now resides in HOL/Library.
   467 
   468 * Entry point to Word library now simply named "Word".
   469 INCOMPATIBILITY.
   470 
   471 * Made source layout more coherent with logical distribution
   472 structure:
   473 
   474     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   475     src/HOL/Library/Code_Message.thy ~> src/HOL/
   476     src/HOL/Library/GCD.thy ~> src/HOL/
   477     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   478     src/HOL/Library/Parity.thy ~> src/HOL/
   479     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   480     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   481     src/HOL/Real/Lubs.thy ~> src/HOL/
   482     src/HOL/Real/PReal.thy ~> src/HOL/
   483     src/HOL/Real/Rational.thy ~> src/HOL/
   484     src/HOL/Real/RComplete.thy ~> src/HOL/
   485     src/HOL/Real/RealDef.thy ~> src/HOL/
   486     src/HOL/Real/RealPow.thy ~> src/HOL/
   487     src/HOL/Real/Real.thy ~> src/HOL/
   488     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   489     src/HOL/Complex/Complex.thy ~> src/HOL/
   490     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   491     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   492     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   493     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   494     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   495     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   496     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   497     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   498     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   499     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   500     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   501     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   502     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   503     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   504     src/HOL/Real/Float ~> src/HOL/Library/
   505     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   506     src/HOL/Real/RealVector.thy ~> src/HOL/
   507 
   508     src/HOL/arith_data.ML ~> src/HOL/Tools
   509     src/HOL/hologic.ML ~> src/HOL/Tools
   510     src/HOL/simpdata.ML ~> src/HOL/Tools
   511     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   512     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   513     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   514     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   515     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   516     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   517     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   518 
   519     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   520     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   521     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   522     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   523     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   524     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   525 
   526 * If methods "eval" and "evaluation" encounter a structured proof
   527 state with !!/==>, only the conclusion is evaluated to True (if
   528 possible), avoiding strange error messages.
   529 
   530 * Method "sizechange" automates termination proofs using (a
   531 modification of) the size-change principle.  Requires SAT solver.  See
   532 src/HOL/ex/Termination.thy for examples.
   533 
   534 * Simplifier: simproc for let expressions now unfolds if bound
   535 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   536 
   537 * Method "arith": Linear arithmetic now ignores all inequalities when
   538 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   539 
   540 * New attribute "arith" for facts that should always be used
   541 automatically by arithmetic. It is intended to be used locally in
   542 proofs, e.g.
   543 
   544   assumes [arith]: "x > 0"
   545 
   546 Global usage is discouraged because of possible performance impact.
   547 
   548 * New classes "top" and "bot" with corresponding operations "top" and
   549 "bot" in theory Orderings; instantiation of class "complete_lattice"
   550 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   551 
   552 * Changed definition lemma "less_fun_def" in order to provide an
   553 instance for preorders on functions; use lemma "less_le" instead.
   554 INCOMPATIBILITY.
   555 
   556 * Theory Orderings: class "wellorder" moved here, with explicit
   557 induction rule "less_induct" as assumption.  For instantiation of
   558 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   559 INCOMPATIBILITY.
   560 
   561 * Theory Orderings: added class "preorder" as superclass of "order".
   562 INCOMPATIBILITY: Instantiation proofs for order, linorder
   563 etc. slightly changed.  Some theorems named order_class.* now named
   564 preorder_class.*.
   565 
   566 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   567 "diag" to "Id_on".
   568 
   569 * Theory Finite_Set: added a new fold combinator of type
   570 
   571   ('a => 'b => 'b) => 'b => 'a set => 'b
   572 
   573 Occasionally this is more convenient than the old fold combinator
   574 which is now defined in terms of the new one and renamed to
   575 fold_image.
   576 
   577 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   578 and "ring_simps" have been replaced by "algebra_simps" (which can be
   579 extended with further lemmas!).  At the moment both still exist but
   580 the former will disappear at some point.
   581 
   582 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   583 class recpower.  Type-specific simp rules for various recpower types
   584 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   585 
   586 rat_power_0    -> power_0
   587 rat_power_Suc  -> power_Suc
   588 realpow_0      -> power_0
   589 realpow_Suc    -> power_Suc
   590 complexpow_0   -> power_0
   591 complexpow_Suc -> power_Suc
   592 power_poly_0   -> power_0
   593 power_poly_Suc -> power_Suc
   594 
   595 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   596 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   597 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   598 of lemmas from Divides has been generalized from nat to class
   599 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   600 renames resulting from duplicate elimination:
   601 
   602     dvd_def_mod ~>          dvd_eq_mod_eq_0
   603     zero_dvd_iff ~>         dvd_0_left_iff
   604     dvd_0 ~>                dvd_0_right
   605     DIVISION_BY_ZERO_DIV ~> div_by_0
   606     DIVISION_BY_ZERO_MOD ~> mod_by_0
   607     mult_div ~>             div_mult_self2_is_id
   608     mult_mod ~>             mod_mult_self2_is_0
   609 
   610 * Theory IntDiv: removed many lemmas that are instances of class-based
   611 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   612 rename old lemmas as follows:
   613 
   614 dvd_diff               -> nat_dvd_diff
   615 dvd_zminus_iff         -> dvd_minus_iff
   616 mod_add1_eq            -> mod_add_eq
   617 mod_mult1_eq           -> mod_mult_right_eq
   618 mod_mult1_eq'          -> mod_mult_left_eq
   619 mod_mult_distrib_mod   -> mod_mult_eq
   620 nat_mod_add_left_eq    -> mod_add_left_eq
   621 nat_mod_add_right_eq   -> mod_add_right_eq
   622 nat_mod_div_trivial    -> mod_div_trivial
   623 nat_mod_mod_trivial    -> mod_mod_trivial
   624 zdiv_zadd_self1        -> div_add_self1
   625 zdiv_zadd_self2        -> div_add_self2
   626 zdiv_zmult_self1       -> div_mult_self2_is_id
   627 zdiv_zmult_self2       -> div_mult_self1_is_id
   628 zdvd_triv_left         -> dvd_triv_left
   629 zdvd_triv_right        -> dvd_triv_right
   630 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   631 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   632 zmod_zadd_left_eq      -> mod_add_left_eq
   633 zmod_zadd_right_eq     -> mod_add_right_eq
   634 zmod_zadd_self1        -> mod_add_self1
   635 zmod_zadd_self2        -> mod_add_self2
   636 zmod_zadd1_eq          -> mod_add_eq
   637 zmod_zdiff1_eq         -> mod_diff_eq
   638 zmod_zdvd_zmod         -> mod_mod_cancel
   639 zmod_zmod_cancel       -> mod_mod_cancel
   640 zmod_zmult_self1       -> mod_mult_self2_is_0
   641 zmod_zmult_self2       -> mod_mult_self1_is_0
   642 zmod_1                 -> mod_by_1
   643 zdiv_1                 -> div_by_1
   644 zdvd_abs1              -> abs_dvd_iff
   645 zdvd_abs2              -> dvd_abs_iff
   646 zdvd_refl              -> dvd_refl
   647 zdvd_trans             -> dvd_trans
   648 zdvd_zadd              -> dvd_add
   649 zdvd_zdiff             -> dvd_diff
   650 zdvd_zminus_iff        -> dvd_minus_iff
   651 zdvd_zminus2_iff       -> minus_dvd_iff
   652 zdvd_zmultD            -> dvd_mult_right
   653 zdvd_zmultD2           -> dvd_mult_left
   654 zdvd_zmult_mono        -> mult_dvd_mono
   655 zdvd_0_right           -> dvd_0_right
   656 zdvd_0_left            -> dvd_0_left_iff
   657 zdvd_1_left            -> one_dvd
   658 zminus_dvd_iff         -> minus_dvd_iff
   659 
   660 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   661 
   662 * The real numbers offer decimal input syntax: 12.34 is translated
   663 into 1234/10^2. This translation is not reversed upon output.
   664 
   665 * Theory Library/Polynomial defines an abstract type 'a poly of
   666 univariate polynomials with coefficients of type 'a.  In addition to
   667 the standard ring operations, it also supports div and mod.  Code
   668 generation is also supported, using list-style constructors.
   669 
   670 * Theory Library/Inner_Product defines a class of real_inner for real
   671 inner product spaces, with an overloaded operation inner :: 'a => 'a
   672 => real.  Class real_inner is a subclass of real_normed_vector from
   673 theory RealVector.
   674 
   675 * Theory Library/Product_Vector provides instances for the product
   676 type 'a * 'b of several classes from RealVector and Inner_Product.
   677 Definitions of addition, subtraction, scalar multiplication, norms,
   678 and inner products are included.
   679 
   680 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   681 addition to the field operations, numerals and case syntax are also
   682 supported.
   683 
   684 * Theory Library/Diagonalize provides constructive version of Cantor's
   685 first diagonalization argument.
   686 
   687 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   688 zlcm (for int); carried together from various gcd/lcm developements in
   689 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   690 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   691 may recover tupled syntax as follows:
   692 
   693     hide (open) const gcd
   694     abbreviation gcd where
   695       "gcd == (%(a, b). GCD.gcd a b)"
   696     notation (output)
   697       GCD.gcd ("gcd '(_, _')")
   698 
   699 The same works for lcm, zgcd, zlcm.
   700 
   701 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   702 instantiations for algebraic structures.  Removed some duplicate
   703 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   704 
   705 * ML antiquotation @{code} takes a constant as argument and generates
   706 corresponding code in background and inserts name of the corresponding
   707 resulting ML value/function/datatype constructor binding in place.
   708 All occurrences of @{code} with a single ML block are generated
   709 simultaneously.  Provides a generic and safe interface for
   710 instrumentalizing code generation.  See
   711 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   712 In future you ought to refrain from ad-hoc compiling generated SML
   713 code on the ML toplevel.  Note that (for technical reasons) @{code}
   714 cannot refer to constants for which user-defined serializations are
   715 set.  Refer to the corresponding ML counterpart directly in that
   716 cases.
   717 
   718 * Command 'rep_datatype': instead of theorem names the command now
   719 takes a list of terms denoting the constructors of the type to be
   720 represented as datatype.  The characteristic theorems have to be
   721 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   722 have disappeared in favour of existing ones:
   723 
   724     unit_induct                 ~> unit.induct
   725     prod_induct                 ~> prod.induct
   726     sum_induct                  ~> sum.induct
   727     Suc_Suc_eq                  ~> nat.inject
   728     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   729 
   730 
   731 *** HOL-Algebra ***
   732 
   733 * New locales for orders and lattices where the equivalence relation
   734 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   735 locales use a record structure with field eq for the equivalence.
   736 
   737 * New theory of factorial domains.
   738 
   739 * Units_l_inv and Units_r_inv are now simp rules by default.
   740 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   741 and/or r_inv will now also require deletion of these lemmas.
   742 
   743 * Renamed the following theorems, INCOMPATIBILITY:
   744 
   745 UpperD ~> Upper_memD
   746 LowerD ~> Lower_memD
   747 least_carrier ~> least_closed
   748 greatest_carrier ~> greatest_closed
   749 greatest_Lower_above ~> greatest_Lower_below
   750 one_zero ~> carrier_one_zero
   751 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   752 
   753 
   754 *** HOL-Nominal ***
   755 
   756 * Nominal datatypes can now contain type-variables.
   757 
   758 * Commands 'nominal_inductive' and 'equivariance' work with local
   759 theory targets.
   760 
   761 * Nominal primrec can now works with local theory targets and its
   762 specification syntax now conforms to the general format as seen in
   763 'inductive' etc.
   764 
   765 * Method "perm_simp" honours the standard simplifier attributes
   766 (no_asm), (no_asm_use) etc.
   767 
   768 * The new predicate #* is defined like freshness, except that on the
   769 left hand side can be a set or list of atoms.
   770 
   771 * Experimental command 'nominal_inductive2' derives strong induction
   772 principles for inductive definitions.  In contrast to
   773 'nominal_inductive', which can only deal with a fixed number of
   774 binders, it can deal with arbitrary expressions standing for sets of
   775 atoms to be avoided.  The only inductive definition we have at the
   776 moment that needs this generalisation is the typing rule for Lets in
   777 the algorithm W:
   778 
   779  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   780  -----------------------------------------------------------------
   781          Gamma |- Let x be t1 in t2 : T2
   782 
   783 In this rule one wants to avoid all the binders that are introduced by
   784 "close Gamma T1".  We are looking for other examples where this
   785 feature might be useful.  Please let us know.
   786 
   787 
   788 *** HOLCF ***
   789 
   790 * Reimplemented the simplification procedure for proving continuity
   791 subgoals.  The new simproc is extensible; users can declare additional
   792 continuity introduction rules with the attribute [cont2cont].
   793 
   794 * The continuity simproc now uses a different introduction rule for
   795 solving continuity subgoals on terms with lambda abstractions.  In
   796 some rare cases the new simproc may fail to solve subgoals that the
   797 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   798 Potential INCOMPATIBILITY.
   799 
   800 * Command 'fixrec': specification syntax now conforms to the general
   801 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   802 examples.  INCOMPATIBILITY.
   803 
   804 
   805 *** ZF ***
   806 
   807 * Proof of Zorn's Lemma for partial orders.
   808 
   809 
   810 *** ML ***
   811 
   812 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   813 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   814 depends on multithreading, so timouts will not work before Poly/ML
   815 5.2.1!
   816 
   817 * High-level support for concurrent ML programming, see
   818 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   819 particularly convenient to organize independent functional
   820 computations.  The concept of "synchronized variables" provides a
   821 higher-order interface for components with shared state, avoiding the
   822 delicate details of mutexes and condition variables.  (Requires
   823 Poly/ML 5.2.1 or later.)
   824 
   825 * ML bindings produced via Isar commands are stored within the Isar
   826 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   827 become thread-safe and work with undo as expected (concerning
   828 top-level bindings, not side-effects on global references).
   829 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   830 compiler at runtime; really global bindings need to be given outside a
   831 theory.  (Requires Poly/ML 5.2 or later.)
   832 
   833 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   834 context.  Top-level ML bindings are stored within the proof context in
   835 a purely sequential fashion, disregarding the nested proof structure.
   836 ML bindings introduced by 'ML_prf' are discarded at the end of the
   837 proof.  (Requires Poly/ML 5.2 or later.)
   838 
   839 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   840 and Method.setup, as well as Isar commands 'attribute_setup' and
   841 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   842 existing code accordingly, or use plain 'setup' together with old
   843 Method.add_method.
   844 
   845 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   846 to 'a -> thm, while results are always tagged with an authentic oracle
   847 name.  The Isar command 'oracle' is now polymorphic, no argument type
   848 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   849 accordingly.  Note that extra performance may be gained by producing
   850 the cterm carefully, avoiding slow Thm.cterm_of.
   851 
   852 * Simplified interface for defining document antiquotations via
   853 ThyOutput.antiquotation, ThyOutput.output, and optionally
   854 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   855 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   856 examples.
   857 
   858 * More systematic treatment of long names, abstract name bindings, and
   859 name space operations.  Basic operations on qualified names have been
   860 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   861 Long_Name.append.  Old type bstring has been mostly replaced by
   862 abstract type binding (see structure Binding), which supports precise
   863 qualification by packages and local theory targets, as well as proper
   864 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   865 bstring values into Binding.name, or better pass through abstract
   866 bindings everywhere.  See further src/Pure/General/long_name.ML,
   867 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   868 
   869 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   870 LocalTheory.note etc.) now refer to the *full* internal name, not the
   871 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   872 
   873 * Disposed old type and term read functions (Sign.read_def_typ,
   874 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   875 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   876 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   877 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   878 resort for legacy applications.
   879 
   880 * Disposed old declarations, tactics, tactic combinators that refer to
   881 the simpset or claset of an implicit theory (such as Addsimps,
   882 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   883 embedded ML text, or local_simpset_of with a proper context passed as
   884 explicit runtime argument.
   885 
   886 * Rules and tactics that read instantiations (read_instantiate,
   887 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   888 context, which is required for parsing and type-checking.  Moreover,
   889 the variables are specified as plain indexnames, not string encodings
   890 thereof.  INCOMPATIBILITY.
   891 
   892 * Generic Toplevel.add_hook interface allows to analyze the result of
   893 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   894 for theorem dependency output of transactions resulting in a new
   895 theory state.
   896 
   897 * ML antiquotations: block-structured compilation context indicated by
   898 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   899 
   900   @{binding name}                         - basic name binding
   901   @{let ?pat = term}                      - term abbreviation (HO matching)
   902   @{note name = fact}                     - fact abbreviation
   903   @{thm fact}                             - singleton fact (with attributes)
   904   @{thms fact}                            - general fact (with attributes)
   905   @{lemma prop by method}                 - singleton goal
   906   @{lemma prop by meth1 meth2}            - singleton goal
   907   @{lemma prop1 ... propN by method}      - general goal
   908   @{lemma prop1 ... propN by meth1 meth2} - general goal
   909   @{lemma (open) ...}                     - open derivation
   910 
   911 
   912 *** System ***
   913 
   914 * The Isabelle "emacs" tool provides a specific interface to invoke
   915 Proof General / Emacs, with more explicit failure if that is not
   916 installed (the old isabelle-interface script silently falls back on
   917 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   918 installation location of the Proof General distribution.
   919 
   920 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   921 the Isabelle process into a JVM/Scala application.  See
   922 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   923 process wrapper has been discontinued.)
   924 
   925 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   926 
   927 * Various status messages (with exact source position information) are
   928 emitted, if proper markup print mode is enabled.  This allows
   929 user-interface components to provide detailed feedback on internal
   930 prover operations.
   931 
   932 
   933 
   934 New in Isabelle2008 (June 2008)
   935 -------------------------------
   936 
   937 *** General ***
   938 
   939 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   940 and updated, with formally checked references as hyperlinks.
   941 
   942 * Theory loader: use_thy (and similar operations) no longer set the
   943 implicit ML context, which was occasionally hard to predict and in
   944 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   945 provides a proper context already.
   946 
   947 * Theory loader: old-style ML proof scripts being *attached* to a thy
   948 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   949 'use' within a theory file will do the job.
   950 
   951 * Name space merge now observes canonical order, i.e. the second space
   952 is inserted into the first one, while existing entries in the first
   953 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   954 swap theory imports.
   955 
   956 * Syntax: symbol \<chi> is now considered a letter.  Potential
   957 INCOMPATIBILITY in identifier syntax etc.
   958 
   959 * Outer syntax: string tokens no longer admit escaped white space,
   960 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   961 white space without escapes.
   962 
   963 * Outer syntax: string tokens may contain arbitrary character codes
   964 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   965 "foo_bar".
   966 
   967 
   968 *** Pure ***
   969 
   970 * Context-dependent token translations.  Default setup reverts locally
   971 fixed variables, and adds hilite markup for undeclared frees.
   972 
   973 * Unused theorems can be found using the new command 'unused_thms'.
   974 There are three ways of invoking it:
   975 
   976 (1) unused_thms
   977      Only finds unused theorems in the current theory.
   978 
   979 (2) unused_thms thy_1 ... thy_n -
   980      Finds unused theorems in the current theory and all of its ancestors,
   981      excluding the theories thy_1 ... thy_n and all of their ancestors.
   982 
   983 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   984      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   985      their ancestors, excluding the theories thy_1 ... thy_n and all of
   986      their ancestors.
   987 
   988 In order to increase the readability of the list produced by
   989 unused_thms, theorems that have been created by a particular instance
   990 of a theory command such as 'inductive' or 'function' are considered
   991 to belong to the same "group", meaning that if at least one theorem in
   992 this group is used, the other theorems in the same group are no longer
   993 reported as unused.  Moreover, if all theorems in the group are
   994 unused, only one theorem in the group is displayed.
   995 
   996 Note that proof objects have to be switched on in order for
   997 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   998 usually the case when using Proof General with the default settings).
   999 
  1000 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1001 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1002 duplicate fact bindings, or even accidental fact duplications.  Note
  1003 that tools may maintain dynamically scoped facts systematically, using
  1004 PureThy.add_thms_dynamic.
  1005 
  1006 * Command 'hide' now allows to hide from "fact" name space as well.
  1007 
  1008 * Eliminated destructive theorem database, simpset, claset, and
  1009 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1010 update of theories within ML code.
  1011 
  1012 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1013 INCOMPATIBILITY, object-logics depending on former Pure require
  1014 additional setup PureThy.old_appl_syntax_setup; object-logics
  1015 depending on former CPure need to refer to Pure.
  1016 
  1017 * Commands 'use' and 'ML' are now purely functional, operating on
  1018 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1019 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1020 INCOMPATIBILITY.
  1021 
  1022 * Command 'setup': discontinued implicit version with ML reference.
  1023 
  1024 * Instantiation target allows for simultaneous specification of class
  1025 instance operations together with an instantiation proof.
  1026 Type-checking phase allows to refer to class operations uniformly.
  1027 See src/HOL/Complex/Complex.thy for an Isar example and
  1028 src/HOL/Library/Eval.thy for an ML example.
  1029 
  1030 * Indexing of literal facts: be more serious about including only
  1031 facts from the visible specification/proof context, but not the
  1032 background context (locale etc.).  Affects `prop` notation and method
  1033 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1034 situations.
  1035 
  1036 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1037 "(open)" option, which used to expose internal bound variables to the
  1038 proof text.
  1039 
  1040 * Isar statements: removed obsolete case "rule_context".
  1041 INCOMPATIBILITY, better use explicit fixes/assumes.
  1042 
  1043 * Locale proofs: default proof step now includes 'unfold_locales';
  1044 hence 'proof' without argument may be used to unfold locale
  1045 predicates.
  1046 
  1047 
  1048 *** Document preparation ***
  1049 
  1050 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1051 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1052 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1053 spot); renamed link color from "darkblue" to "linkcolor" (default
  1054 value unchanged, can be redefined via \definecolor); no longer sets
  1055 "a4paper" option (unnecessary or even intrusive).
  1056 
  1057 * Antiquotation @{lemma A method} proves proposition A by the given
  1058 method (either a method name or a method name plus (optional) method
  1059 arguments in parentheses) and prints A just like @{prop A}.
  1060 
  1061 
  1062 *** HOL ***
  1063 
  1064 * New primrec package.  Specification syntax conforms in style to
  1065 definition/function/....  No separate induction rule is provided.  The
  1066 "primrec" command distinguishes old-style and new-style specifications
  1067 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1068 When adjusting theories, beware: constants stemming from new-style
  1069 primrec specifications have authentic syntax.
  1070 
  1071 * Metis prover is now an order of magnitude faster, and also works
  1072 with multithreading.
  1073 
  1074 * Metis: the maximum number of clauses that can be produced from a
  1075 theorem is now given by the attribute max_clauses.  Theorems that
  1076 exceed this number are ignored, with a warning printed.
  1077 
  1078 * Sledgehammer no longer produces structured proofs by default. To
  1079 enable, declare [[sledgehammer_full = true]].  Attributes
  1080 reconstruction_modulus, reconstruction_sorts renamed
  1081 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1082 
  1083 * Method "induct_scheme" derives user-specified induction rules
  1084 from well-founded induction and completeness of patterns. This factors
  1085 out some operations that are done internally by the function package
  1086 and makes them available separately.  See
  1087 src/HOL/ex/Induction_Scheme.thy for examples.
  1088 
  1089 * More flexible generation of measure functions for termination
  1090 proofs: Measure functions can be declared by proving a rule of the
  1091 form "is_measure f" and giving it the [measure_function] attribute.
  1092 The "is_measure" predicate is logically meaningless (always true), and
  1093 just guides the heuristic.  To find suitable measure functions, the
  1094 termination prover sets up the goal "is_measure ?f" of the appropriate
  1095 type and generates all solutions by prolog-style backwards proof using
  1096 the declared rules.
  1097 
  1098 This setup also deals with rules like 
  1099 
  1100   "is_measure f ==> is_measure (list_size f)"
  1101 
  1102 which accommodates nested datatypes that recurse through lists.
  1103 Similar rules are predeclared for products and option types.
  1104 
  1105 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1106 
  1107   INCOMPATIBILITIES:
  1108 
  1109   - Definitions of overloaded constants on sets have to be replaced by
  1110     definitions on => and bool.
  1111 
  1112   - Some definitions of overloaded operators on sets can now be proved
  1113     using the definitions of the operators on => and bool.  Therefore,
  1114     the following theorems have been renamed:
  1115 
  1116       subset_def   -> subset_eq
  1117       psubset_def  -> psubset_eq
  1118       set_diff_def -> set_diff_eq
  1119       Compl_def    -> Compl_eq
  1120       Sup_set_def  -> Sup_set_eq
  1121       Inf_set_def  -> Inf_set_eq
  1122       sup_set_def  -> sup_set_eq
  1123       inf_set_def  -> inf_set_eq
  1124 
  1125   - Due to the incompleteness of the HO unification algorithm, some
  1126     rules such as subst may require manual instantiation, if some of
  1127     the unknowns in the rule is a set.
  1128 
  1129   - Higher order unification and forward proofs:
  1130     The proof pattern
  1131 
  1132       have "P (S::'a set)" <...>
  1133       then have "EX S. P S" ..
  1134 
  1135     no longer works (due to the incompleteness of the HO unification
  1136     algorithm) and must be replaced by the pattern
  1137 
  1138       have "EX S. P S"
  1139       proof
  1140         show "P S" <...>
  1141       qed
  1142 
  1143   - Calculational reasoning with subst (or similar rules):
  1144     The proof pattern
  1145 
  1146       have "P (S::'a set)" <...>
  1147       also have "S = T" <...>
  1148       finally have "P T" .
  1149 
  1150     no longer works (for similar reasons as the previous example) and
  1151     must be replaced by something like
  1152 
  1153       have "P (S::'a set)" <...>
  1154       moreover have "S = T" <...>
  1155       ultimately have "P T" by simp
  1156 
  1157   - Tactics or packages written in ML code:
  1158     Code performing pattern matching on types via
  1159 
  1160       Type ("set", [T]) => ...
  1161 
  1162     must be rewritten. Moreover, functions like strip_type or
  1163     binder_types no longer return the right value when applied to a
  1164     type of the form
  1165 
  1166       T1 => ... => Tn => U => bool
  1167 
  1168     rather than
  1169 
  1170       T1 => ... => Tn => U set
  1171 
  1172 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1173 Wellfounded_Relations to theory Wellfounded.
  1174 
  1175 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1176 
  1177 * Class finite no longer treats UNIV as class parameter.  Use class
  1178 enum from theory Library/Enum instead to achieve a similar effect.
  1179 INCOMPATIBILITY.
  1180 
  1181 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1182 and "Cons".  INCOMPATIBILITY.
  1183 
  1184 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1185 Potential INCOMPATIBILITY.
  1186 
  1187 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1188 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1189 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1190 
  1191 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1192 the same name in theory Orderings:
  1193 
  1194   less_trans
  1195   less_linear
  1196   le_imp_less_or_eq
  1197   le_less_trans
  1198   less_le_trans
  1199   less_not_sym
  1200   less_asym
  1201 
  1202 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1203 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1204 and different variable names.
  1205 
  1206 * Library/Option_ord.thy: Canonical order on option type.
  1207 
  1208 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1209 finite maps.
  1210 
  1211 * Library/Countable.thy: Type class for countable types.
  1212 
  1213 * Theory Int: The representation of numerals has changed.  The infix
  1214 operator BIT and the bit datatype with constructors B0 and B1 have
  1215 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1216 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1217 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1218 accordingly.
  1219 
  1220 * Theory Nat: definition of <= and < on natural numbers no longer
  1221 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1222 le_def and less_def have disappeared.  Consider lemmas not_less
  1223 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1224 
  1225 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1226 (whose purpose mainly is for various fold_set functionals) have been
  1227 abandoned in favor of the existing algebraic classes
  1228 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1229 lower_semilattice (resp. upper_semilattice) and linorder.
  1230 INCOMPATIBILITY.
  1231 
  1232 * Theory Transitive_Closure: induct and cases rules now declare proper
  1233 case_names ("base" and "step").  INCOMPATIBILITY.
  1234 
  1235 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1236 lattices.  The form set-specific version is available as
  1237 Inductive.lfp_ordinal_induct_set.
  1238 
  1239 * Renamed theorems "power.simps" to "power_int.simps".
  1240 INCOMPATIBILITY.
  1241 
  1242 * Class semiring_div provides basic abstract properties of semirings
  1243 with division and modulo operations.  Subsumes former class dvd_mod.
  1244 
  1245 * Merged theories IntDef, Numeral and IntArith into unified theory
  1246 Int.  INCOMPATIBILITY.
  1247 
  1248 * Theory Library/Code_Index: type "index" now represents natural
  1249 numbers rather than integers.  INCOMPATIBILITY.
  1250 
  1251 * New class "uminus" with operation "uminus" (split of from class
  1252 "minus" which now only has operation "minus", binary).
  1253 INCOMPATIBILITY.
  1254 
  1255 * Constants "card", "internal_split", "option_map" now with authentic
  1256 syntax.  INCOMPATIBILITY.
  1257 
  1258 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1259 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1260 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1261 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1262 Sup_set_def, le_def, less_def, option_map_def now with object
  1263 equality.  INCOMPATIBILITY.
  1264 
  1265 * Records. Removed K_record, and replaced it by pure lambda term
  1266 %x. c. The simplifier setup is now more robust against eta expansion.
  1267 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1268 
  1269 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1270 
  1271 * Library/ListVector: new theory of arithmetic vector operations.
  1272 
  1273 * Library/Order_Relation: new theory of various orderings as sets of
  1274 pairs.  Defines preorders, partial orders, linear orders and
  1275 well-orders on sets and on types.
  1276 
  1277 
  1278 *** ZF ***
  1279 
  1280 * Renamed some theories to allow to loading both ZF and HOL in the
  1281 same session:
  1282 
  1283   Datatype  -> Datatype_ZF
  1284   Inductive -> Inductive_ZF
  1285   Int       -> Int_ZF
  1286   IntDiv    -> IntDiv_ZF
  1287   Nat       -> Nat_ZF
  1288   List      -> List_ZF
  1289   Main      -> Main_ZF
  1290 
  1291 INCOMPATIBILITY: ZF theories that import individual theories below
  1292 Main might need to be adapted.  Regular theory Main is still
  1293 available, as trivial extension of Main_ZF.
  1294 
  1295 
  1296 *** ML ***
  1297 
  1298 * ML within Isar: antiquotation @{const name} or @{const
  1299 name(typargs)} produces statically-checked Const term.
  1300 
  1301 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1302 (of the same name).  Removed obsolete print command.
  1303 
  1304 * Removed obsolete "use_legacy_bindings" function.
  1305 
  1306 * The ``print mode'' is now a thread-local value derived from a global
  1307 template (the former print_mode reference), thus access becomes
  1308 non-critical.  The global print_mode reference is for session
  1309 management only; user-code should use print_mode_value,
  1310 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1311 
  1312 * Functions system/system_out provide a robust way to invoke external
  1313 shell commands, with propagation of interrupts (requires Poly/ML
  1314 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1315 
  1316 
  1317 *** System ***
  1318 
  1319 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1320 in accordance with Proof General 3.7, which prefers GNU emacs.
  1321 
  1322 * isatool tty runs Isabelle process with plain tty interaction;
  1323 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1324 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1325 
  1326 * isatool browser now works with Cygwin as well, using general
  1327 "javapath" function defined in Isabelle process environment.
  1328 
  1329 * YXML notation provides a simple and efficient alternative to
  1330 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1331 isatool yxml as described in the Isabelle system manual.
  1332 
  1333 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1334 provides general wrapper for managing an Isabelle process in a robust
  1335 fashion, with ``cooked'' output from stdin/stderr.
  1336 
  1337 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1338 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1339 
  1340 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1341 way of changing the user's settings is via
  1342 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1343 script.
  1344 
  1345 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1346 cores of the underlying machine, which is a good starting point for
  1347 optimal performance tuning.  The corresponding usedir option -M allows
  1348 "max" as an alias for "0".  WARNING: does not work on certain versions
  1349 of Mac OS (with Poly/ML 5.1).
  1350 
  1351 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1352 adverse effect of Isabelle flooding interactive front-ends (notably
  1353 ProofGeneral / XEmacs).
  1354 
  1355 
  1356 
  1357 New in Isabelle2007 (November 2007)
  1358 -----------------------------------
  1359 
  1360 *** General ***
  1361 
  1362 * More uniform information about legacy features, notably a
  1363 warning/error of "Legacy feature: ...", depending on the state of the
  1364 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1365 legacy features will disappear eventually.
  1366 
  1367 * Theory syntax: the header format ``theory A = B + C:'' has been
  1368 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1369 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1370 
  1371 * Theory syntax: the old non-Isar theory file format has been
  1372 discontinued altogether.  Note that ML proof scripts may still be used
  1373 with Isar theories; migration is usually quite simple with the ML
  1374 function use_legacy_bindings.  INCOMPATIBILITY.
  1375 
  1376 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1377 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1378 quotes.
  1379 
  1380 * Theory loader: be more serious about observing the static theory
  1381 header specifications (including optional directories), but not the
  1382 accidental file locations of previously successful loads.  The strict
  1383 update policy of former update_thy is now already performed by
  1384 use_thy, so the former has been removed; use_thys updates several
  1385 theories simultaneously, just as 'imports' within a theory header
  1386 specification, but without merging the results.  Potential
  1387 INCOMPATIBILITY: may need to refine theory headers and commands
  1388 ROOT.ML which depend on load order.
  1389 
  1390 * Theory loader: optional support for content-based file
  1391 identification, instead of the traditional scheme of full physical
  1392 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1393 (cf. the system manual).  The new scheme allows to work with
  1394 non-finished theories in persistent session images, such that source
  1395 files may be moved later on without requiring reloads.
  1396 
  1397 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1398 file (with the same base name as the theory) are considered a legacy
  1399 feature, which will disappear eventually. Even now, the theory loader
  1400 no longer maintains dependencies on such files.
  1401 
  1402 * Syntax: the scope for resolving ambiguities via type-inference is
  1403 now limited to individual terms, instead of whole simultaneous
  1404 specifications as before. This greatly reduces the complexity of the
  1405 syntax module and improves flexibility by separating parsing and
  1406 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1407 'fixes' etc.) are required in rare situations.
  1408 
  1409 * Syntax: constants introduced by new-style packages ('definition',
  1410 'abbreviation' etc.) are passed through the syntax module in
  1411 ``authentic mode''. This means that associated mixfix annotations
  1412 really stick to such constants, independently of potential name space
  1413 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1414 trees are represented slightly differently, may need to adapt syntax
  1415 translations accordingly. Use CONST marker in 'translations' and
  1416 @{const_syntax} antiquotation in 'parse_translation' etc.
  1417 
  1418 * Legacy goal package: reduced interface to the bare minimum required
  1419 to keep existing proof scripts running.  Most other user-level
  1420 functions are now part of the OldGoals structure, which is *not* open
  1421 by default (consider isatool expandshort before open OldGoals).
  1422 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1423 these tend to cause confusion about the actual goal (!) context being
  1424 used here, which is not necessarily the same as the_context().
  1425 
  1426 * Command 'find_theorems': supports "*" wild-card in "name:"
  1427 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1428 support a specific search form (see ProofGeneral/CHANGES).
  1429 
  1430 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1431 by default, which means that "prems" (and also "fixed variables") are
  1432 suppressed from proof state output.  Note that the ProofGeneral
  1433 settings mechanism allows to change and save options persistently, but
  1434 older versions of Isabelle will fail to start up if a negative prems
  1435 limit is imposed.
  1436 
  1437 * Local theory targets may be specified by non-nested blocks of
  1438 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1439 contain definitions, theorems etc., including any derived mechanism
  1440 that has been implemented on top of these primitives.  This concept
  1441 generalizes the existing ``theorem (in ...)'' towards more versatility
  1442 and scalability.
  1443 
  1444 * Proof General interface: proper undo of final 'end' command;
  1445 discontinued Isabelle/classic mode (ML proof scripts).
  1446 
  1447 
  1448 *** Document preparation ***
  1449 
  1450 * Added antiquotation @{theory name} which prints the given name,
  1451 after checking that it refers to a valid ancestor theory in the
  1452 current context.
  1453 
  1454 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1455 check the given source text as ML type/structure, printing verbatim.
  1456 
  1457 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1458 "c args == rhs" given in the current context.  (Any number of
  1459 arguments may be given on the LHS.)
  1460 
  1461 
  1462 *** Pure ***
  1463 
  1464 * The 'class' package offers a combination of axclass and locale to
  1465 achieve Haskell-like type classes in Isabelle.  Definitions and
  1466 theorems within a class context produce both relative results (with
  1467 implicit parameters according to the locale context), and polymorphic
  1468 constants with qualified polymorphism (according to the class
  1469 context).  Within the body context of a 'class' target, a separate
  1470 syntax layer ("user space type system") takes care of converting
  1471 between global polymorphic consts and internal locale representation.
  1472 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1473 "isatool doc classes" provides a tutorial.
  1474 
  1475 * Generic code generator framework allows to generate executable
  1476 code for ML and Haskell (including Isabelle classes).  A short usage
  1477 sketch:
  1478 
  1479     internal compilation:
  1480         export_code <list of constants (term syntax)> in SML
  1481     writing SML code to a file:
  1482         export_code <list of constants (term syntax)> in SML <filename>
  1483     writing OCaml code to a file:
  1484         export_code <list of constants (term syntax)> in OCaml <filename>
  1485     writing Haskell code to a bunch of files:
  1486         export_code <list of constants (term syntax)> in Haskell <filename>
  1487 
  1488     evaluating closed propositions to True/False using code generation:
  1489         method ``eval''
  1490 
  1491 Reasonable default setup of framework in HOL.
  1492 
  1493 Theorem attributs for selecting and transforming function equations theorems:
  1494 
  1495     [code fun]:        select a theorem as function equation for a specific constant
  1496     [code fun del]:    deselect a theorem as function equation for a specific constant
  1497     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1498     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1499 
  1500 User-defined serializations (target in {SML, OCaml, Haskell}):
  1501 
  1502     code_const <and-list of constants (term syntax)>
  1503       {(target) <and-list of const target syntax>}+
  1504 
  1505     code_type <and-list of type constructors>
  1506       {(target) <and-list of type target syntax>}+
  1507 
  1508     code_instance <and-list of instances>
  1509       {(target)}+
  1510         where instance ::= <type constructor> :: <class>
  1511 
  1512     code_class <and_list of classes>
  1513       {(target) <and-list of class target syntax>}+
  1514         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1515 
  1516 code_instance and code_class only are effective to target Haskell.
  1517 
  1518 For example usage see src/HOL/ex/Codegenerator.thy and
  1519 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1520 generation from Isabelle/HOL theories is available via "isatool doc
  1521 codegen".
  1522 
  1523 * Code generator: consts in 'consts_code' Isar commands are now
  1524 referred to by usual term syntax (including optional type
  1525 annotations).
  1526 
  1527 * Command 'no_translations' removes translation rules from theory
  1528 syntax.
  1529 
  1530 * Overloaded definitions are now actually checked for acyclic
  1531 dependencies.  The overloading scheme is slightly more general than
  1532 that of Haskell98, although Isabelle does not demand an exact
  1533 correspondence to type class and instance declarations.
  1534 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1535 exotic versions of overloading -- at the discretion of the user!
  1536 
  1537 Polymorphic constants are represented via type arguments, i.e. the
  1538 instantiation that matches an instance against the most general
  1539 declaration given in the signature.  For example, with the declaration
  1540 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1541 as c(nat).  Overloading is essentially simultaneous structural
  1542 recursion over such type arguments.  Incomplete specification patterns
  1543 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1544 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1545 Command 'print_theory' outputs the normalized system of recursive
  1546 equations, see section "definitions".
  1547 
  1548 * Configuration options are maintained within the theory or proof
  1549 context (with name and type bool/int/string), providing a very simple
  1550 interface to a poor-man's version of general context data.  Tools may
  1551 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1552 these values using Config.get etc.  Users may change options via an
  1553 associated attribute of the same name.  This form of context
  1554 declaration works particularly well with commands 'declare' or
  1555 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1556 very easy to avoid global references, which would not observe Isar
  1557 toplevel undo/redo and fail to work with multithreading.
  1558 
  1559 Various global ML references of Pure and HOL have been turned into
  1560 configuration options:
  1561 
  1562   Unify.search_bound		unify_search_bound
  1563   Unify.trace_bound		unify_trace_bound
  1564   Unify.trace_simp		unify_trace_simp
  1565   Unify.trace_types		unify_trace_types
  1566   Simplifier.simp_depth_limit	simp_depth_limit
  1567   Blast.depth_limit		blast_depth_limit
  1568   DatatypeProp.dtK		datatype_distinctness_limit
  1569   fast_arith_neq_limit  	fast_arith_neq_limit
  1570   fast_arith_split_limit	fast_arith_split_limit
  1571 
  1572 * Named collections of theorems may be easily installed as context
  1573 data using the functor NamedThmsFun (see also
  1574 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1575 attributes; there is also a toplevel print command.  This facility is
  1576 just a common case of general context data, which is the preferred way
  1577 for anything more complex than just a list of facts in canonical
  1578 order.
  1579 
  1580 * Isar: command 'declaration' augments a local theory by generic
  1581 declaration functions written in ML.  This enables arbitrary content
  1582 being added to the context, depending on a morphism that tells the
  1583 difference of the original declaration context wrt. the application
  1584 context encountered later on.
  1585 
  1586 * Isar: proper interfaces for simplification procedures.  Command
  1587 'simproc_setup' declares named simprocs (with match patterns, and body
  1588 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1589 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1590 
  1591 * Isar: an extra pair of brackets around attribute declarations
  1592 abbreviates a theorem reference involving an internal dummy fact,
  1593 which will be ignored later --- only the effect of the attribute on
  1594 the background context will persist.  This form of in-place
  1595 declarations is particularly useful with commands like 'declare' and
  1596 'using', for example ``have A using [[simproc a]] by simp''.
  1597 
  1598 * Isar: method "assumption" (and implicit closing of subproofs) now
  1599 takes simple non-atomic goal assumptions into account: after applying
  1600 an assumption as a rule the resulting subgoals are solved by atomic
  1601 assumption steps.  This is particularly useful to finish 'obtain'
  1602 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1603 without referring to the original premise "!!x. P x ==> thesis" in the
  1604 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1605 more permissive.
  1606 
  1607 * Isar: implicit use of prems from the Isar proof context is
  1608 considered a legacy feature.  Common applications like ``have A .''
  1609 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1610 referencing facts explicitly here improves readability and
  1611 maintainability of proof texts.
  1612 
  1613 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1614 the obtained context from the course of reasoning!  For example:
  1615 
  1616   assume "EX x y. A x & B y"   -- "any previous fact"
  1617   then guess x and y by clarify
  1618 
  1619 This technique is potentially adventurous, depending on the facts and
  1620 proof tools being involved here.
  1621 
  1622 * Isar: known facts from the proof context may be specified as literal
  1623 propositions, using ASCII back-quote syntax.  This works wherever
  1624 named facts used to be allowed so far, in proof commands, proof
  1625 methods, attributes etc.  Literal facts are retrieved from the context
  1626 according to unification of type and term parameters.  For example,
  1627 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1628 theorems in the current context, then these are valid literal facts:
  1629 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1630 
  1631 There is also a proof method "fact" which does the same composition
  1632 for explicit goal states, e.g. the following proof texts coincide with
  1633 certain special cases of literal facts:
  1634 
  1635   have "A" by fact                 ==  note `A`
  1636   have "A ==> B" by fact           ==  note `A ==> B`
  1637   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1638   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1639 
  1640 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1641 outer syntax.  Thus symbolic identifiers may be used without
  1642 additional white space in declarations like this: ``assume *: A''.
  1643 
  1644 * Isar: 'print_facts' prints all local facts of the current context,
  1645 both named and unnamed ones.
  1646 
  1647 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1648 
  1649   def x == "t" and y == "u"
  1650 
  1651 * Isar: added command 'unfolding', which is structurally similar to
  1652 'using', but affects both the goal state and facts by unfolding given
  1653 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1654 'unfolded' attribute may be replaced by first-class proof text.
  1655 
  1656 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1657 and command 'unfolding' now all support object-level equalities
  1658 (potentially conditional).  The underlying notion of rewrite rule is
  1659 analogous to the 'rule_format' attribute, but *not* that of the
  1660 Simplifier (which is usually more generous).
  1661 
  1662 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1663 premises of a theorem by n. Useful in conjunction with drule.
  1664 
  1665 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1666 method expression within a sandbox consisting of the first N
  1667 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1668 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1669 simplifies all new goals that emerge from applying rule foo to the
  1670 originally first one.
  1671 
  1672 * Isar: schematic goals are no longer restricted to higher-order
  1673 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1674 expected.
  1675 
  1676 * Isar: the conclusion of a long theorem statement is now either
  1677 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1678 (essentially a disjunction of cases with local parameters and
  1679 assumptions).  The latter allows to express general elimination rules
  1680 adequately; in this notation common elimination rules look like this:
  1681 
  1682   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1683     assumes "EX x. P x"
  1684     obtains x where "P x"
  1685 
  1686   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1687     assumes "A & B"
  1688     obtains A and B
  1689 
  1690   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1691     assumes "A | B"
  1692     obtains
  1693       A
  1694     | B
  1695 
  1696 The subsequent classical rules even refer to the formal "thesis"
  1697 explicitly:
  1698 
  1699   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1700     obtains "~ thesis"
  1701 
  1702   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1703     obtains "thesis ==> something"
  1704 
  1705 The actual proof of an 'obtains' statement is analogous to that of the
  1706 Isar proof element 'obtain', only that there may be several cases.
  1707 Optional case names may be specified in parentheses; these will be
  1708 available both in the present proof and as annotations in the
  1709 resulting rule, for later use with the 'cases' method (cf. attribute
  1710 case_names).
  1711 
  1712 * Isar: the assumptions of a long theorem statement are available as
  1713 "assms" fact in the proof context.  This is more appropriate than the
  1714 (historical) "prems", which refers to all assumptions of the current
  1715 context, including those from the target locale, proof body etc.
  1716 
  1717 * Isar: 'print_statement' prints theorems from the current theory or
  1718 proof context in long statement form, according to the syntax of a
  1719 top-level lemma.
  1720 
  1721 * Isar: 'obtain' takes an optional case name for the local context
  1722 introduction rule (default "that").
  1723 
  1724 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1725 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1726 to occur.
  1727 
  1728 * Pure: syntax "CONST name" produces a fully internalized constant
  1729 according to the current context.  This is particularly useful for
  1730 syntax translations that should refer to internal constant
  1731 representations independently of name spaces.
  1732 
  1733 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1734 instead of "FOO ". This allows multiple binder declarations to coexist
  1735 in the same context.  INCOMPATIBILITY.
  1736 
  1737 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1738 primitive that also works in a locale context (both for constants and
  1739 fixed variables). Type declaration and internal syntactic representation
  1740 of given constants retrieved from the context. Likewise, the
  1741 'no_notation' command allows to remove given syntax annotations from the
  1742 current context.
  1743 
  1744 * Isar/locales: new derived specification elements 'axiomatization',
  1745 'definition', 'abbreviation', which support type-inference, admit
  1746 object-level specifications (equality, equivalence).  See also the
  1747 isar-ref manual.  Examples:
  1748 
  1749   axiomatization
  1750     eq  (infix "===" 50) where
  1751     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1752 
  1753   definition "f x y = x + y + 1"
  1754   definition g where "g x = f x x"
  1755 
  1756   abbreviation
  1757     neq  (infix "=!=" 50) where
  1758     "x =!= y == ~ (x === y)"
  1759 
  1760 These specifications may be also used in a locale context.  Then the
  1761 constants being introduced depend on certain fixed parameters, and the
  1762 constant name is qualified by the locale base name.  An internal
  1763 abbreviation takes care for convenient input and output, making the
  1764 parameters implicit and using the original short name.  See also
  1765 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1766 entities from a monomorphic theory.
  1767 
  1768 Presently, abbreviations are only available 'in' a target locale, but
  1769 not inherited by general import expressions.  Also note that
  1770 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1771 'translations' in common applications.  The "no_abbrevs" print mode
  1772 prevents folding of abbreviations in term output.
  1773 
  1774 Concrete syntax is attached to specified constants in internal form,
  1775 independently of name spaces.  The parse tree representation is
  1776 slightly different -- use 'notation' instead of raw 'syntax', and
  1777 'translations' with explicit "CONST" markup to accommodate this.
  1778 
  1779 * Pure/Isar: unified syntax for new-style specification mechanisms
  1780 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1781 full type inference and dummy patterns ("_").  For example:
  1782 
  1783   definition "K x _ = x"
  1784 
  1785   inductive conj for A B
  1786   where "A ==> B ==> conj A B"
  1787 
  1788 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1789 the current context.  Print mode "no_abbrevs" prevents inversion of
  1790 abbreviations on output.
  1791 
  1792 * Isar/locales: improved parameter handling: use of locales "var" and
  1793 "struct" no longer necessary; - parameter renamings are no longer
  1794 required to be injective.  For example, this allows to define
  1795 endomorphisms as locale endom = homom mult mult h.
  1796 
  1797 * Isar/locales: changed the way locales with predicates are defined.
  1798 Instead of accumulating the specification, the imported expression is
  1799 now an interpretation.  INCOMPATIBILITY: different normal form of
  1800 locale expressions.  In particular, in interpretations of locales with
  1801 predicates, goals repesenting already interpreted fragments are not
  1802 removed automatically.  Use methods `intro_locales' and
  1803 `unfold_locales'; see below.
  1804 
  1805 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1806 provide backward reasoning on locales predicates.  The methods are
  1807 aware of interpretations and discharge corresponding goals.
  1808 `intro_locales' is less aggressive then `unfold_locales' and does not
  1809 unfold predicates to assumptions.
  1810 
  1811 * Isar/locales: the order in which locale fragments are accumulated
  1812 has changed.  This enables to override declarations from fragments due
  1813 to interpretations -- for example, unwanted simp rules.
  1814 
  1815 * Isar/locales: interpretation in theories and proof contexts has been
  1816 extended.  One may now specify (and prove) equations, which are
  1817 unfolded in interpreted theorems.  This is useful for replacing
  1818 defined concepts (constants depending on locale parameters) by
  1819 concepts already existing in the target context.  Example:
  1820 
  1821   interpretation partial_order ["op <= :: [int, int] => bool"]
  1822     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1823 
  1824 Typically, the constant `partial_order.less' is created by a
  1825 definition specification element in the context of locale
  1826 partial_order.
  1827 
  1828 * Method "induct": improved internal context management to support
  1829 local fixes and defines on-the-fly. Thus explicit meta-level
  1830 connectives !!  and ==> are rarely required anymore in inductive goals
  1831 (using object-logic connectives for this purpose has been long
  1832 obsolete anyway). Common proof patterns are explained in
  1833 src/HOL/Induct/Common_Patterns.thy, see also
  1834 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1835 examples.
  1836 
  1837 * Method "induct": improved handling of simultaneous goals. Instead of
  1838 introducing object-level conjunction, the statement is now split into
  1839 several conclusions, while the corresponding symbolic cases are nested
  1840 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1841 see src/HOL/Induct/Common_Patterns.thy, for example.
  1842 
  1843 * Method "induct": mutual induction rules are now specified as a list
  1844 of rule sharing the same induction cases. HOL packages usually provide
  1845 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1846 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1847 mutual induction rules differently, i.e. like this:
  1848 
  1849   (induct rule: foo_bar.inducts)
  1850   (induct set: foo bar)
  1851   (induct pred: foo bar)
  1852   (induct type: foo bar)
  1853 
  1854 The ML function ProjectRule.projections turns old-style rules into the
  1855 new format.
  1856 
  1857 * Method "coinduct": dual of induction, see
  1858 src/HOL/Library/Coinductive_List.thy for various examples.
  1859 
  1860 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1861 considered a legacy feature.
  1862 
  1863 * Attribute "symmetric" produces result with standardized schematic
  1864 variables (index 0).  Potential INCOMPATIBILITY.
  1865 
  1866 * Simplifier: by default the simplifier trace only shows top level
  1867 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1868 default. Thus there is less danger of being flooded by the trace. The
  1869 trace indicates where parts have been suppressed.
  1870   
  1871 * Provers/classical: removed obsolete classical version of elim_format
  1872 attribute; classical elim/dest rules are now treated uniformly when
  1873 manipulating the claset.
  1874 
  1875 * Provers/classical: stricter checks to ensure that supplied intro,
  1876 dest and elim rules are well-formed; dest and elim rules must have at
  1877 least one premise.
  1878 
  1879 * Provers/classical: attributes dest/elim/intro take an optional
  1880 weight argument for the rule (just as the Pure versions).  Weights are
  1881 ignored by automated tools, but determine the search order of single
  1882 rule steps.
  1883 
  1884 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1885 where the body does not mention the bound variable.  Note that dummy
  1886 patterns implicitly depend on their context of bounds, which makes
  1887 "{_. _}" match any set comprehension as expected.  Potential
  1888 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1889 constant "_idtdummy" in the binding position.
  1890 
  1891 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1892 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1893 for example "A -> B" => "Pi A (%_. B)".
  1894 
  1895 * Pure: 'class_deps' command visualizes the subclass relation, using
  1896 the graph browser tool.
  1897 
  1898 * Pure: 'print_theory' now suppresses certain internal declarations by
  1899 default; use '!' option for full details.
  1900 
  1901 
  1902 *** HOL ***
  1903 
  1904 * Method "metis" proves goals by applying the Metis general-purpose
  1905 resolution prover (see also http://gilith.com/software/metis/).
  1906 Examples are in the directory MetisExamples.  WARNING: the
  1907 Isabelle/HOL-Metis integration does not yet work properly with
  1908 multi-threading.
  1909   
  1910 * Command 'sledgehammer' invokes external automatic theorem provers as
  1911 background processes.  It generates calls to the "metis" method if
  1912 successful. These can be pasted into the proof.  Users do not have to
  1913 wait for the automatic provers to return.  WARNING: does not really
  1914 work with multi-threading.
  1915 
  1916 * New "auto_quickcheck" feature tests outermost goal statements for
  1917 potential counter-examples.  Controlled by ML references
  1918 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1919 5000 milliseconds).  Fails silently if statements is outside of
  1920 executable fragment, or any other codgenerator problem occurs.
  1921 
  1922 * New constant "undefined" with axiom "undefined x = undefined".
  1923 
  1924 * Added class "HOL.eq", allowing for code generation with polymorphic
  1925 equality.
  1926 
  1927 * Some renaming of class constants due to canonical name prefixing in
  1928 the new 'class' package:
  1929 
  1930     HOL.abs ~> HOL.abs_class.abs
  1931     HOL.divide ~> HOL.divide_class.divide
  1932     0 ~> HOL.zero_class.zero
  1933     1 ~> HOL.one_class.one
  1934     op + ~> HOL.plus_class.plus
  1935     op - ~> HOL.minus_class.minus
  1936     uminus ~> HOL.minus_class.uminus
  1937     op * ~> HOL.times_class.times
  1938     op < ~> HOL.ord_class.less
  1939     op <= > HOL.ord_class.less_eq
  1940     Nat.power ~> Power.power_class.power
  1941     Nat.size ~> Nat.size_class.size
  1942     Numeral.number_of ~> Numeral.number_class.number_of
  1943     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1944     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1945     Orderings.min ~> Orderings.ord_class.min
  1946     Orderings.max ~> Orderings.ord_class.max
  1947     Divides.op div ~> Divides.div_class.div
  1948     Divides.op mod ~> Divides.div_class.mod
  1949     Divides.op dvd ~> Divides.div_class.dvd
  1950 
  1951 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1952 
  1953 a) User-defined constants using any of the names "plus", "minus",
  1954 "times", "less" or "less_eq". The standard syntax translations for
  1955 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1956 names.
  1957 
  1958 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1959 INCOMPATIBILITY: use more specific names.
  1960 
  1961 c) Permutative equations (e.g. "a + b = b + a")
  1962 Since the change of names also changes the order of terms, permutative
  1963 rewrite rules may get applied in a different order. Experience shows
  1964 that this is rarely the case (only two adaptions in the whole Isabelle
  1965 distribution).  INCOMPATIBILITY: rewrite proofs
  1966 
  1967 d) ML code directly refering to constant names
  1968 This in general only affects hand-written proof tactics, simprocs and
  1969 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1970 Consider using @{const_name} antiquotation.
  1971 
  1972 * New class "default" with associated constant "default".
  1973 
  1974 * Function "sgn" is now overloaded and available on int, real, complex
  1975 (and other numeric types), using class "sgn".  Two possible defs of
  1976 sgn are given as equational assumptions in the classes sgn_if and
  1977 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1978 INCOMPATIBILITY.
  1979 
  1980 * Locale "partial_order" now unified with class "order" (cf. theory
  1981 Orderings), added parameter "less".  INCOMPATIBILITY.
  1982 
  1983 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1984 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1985 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1986 
  1987 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1988 changed order of proof goals in instance proofs.
  1989 
  1990 * The transitivity reasoner for partial and linear orders is set up
  1991 for classes "order" and "linorder".  Instances of the reasoner are available
  1992 in all contexts importing or interpreting the corresponding locales.
  1993 Method "order" invokes the reasoner separately; the reasoner
  1994 is also integrated with the Simplifier as a solver.  Diagnostic
  1995 command 'print_orders' shows the available instances of the reasoner
  1996 in the current context.
  1997 
  1998 * Localized monotonicity predicate in theory "Orderings"; integrated
  1999 lemmas max_of_mono and min_of_mono with this predicate.
  2000 INCOMPATIBILITY.
  2001 
  2002 * Formulation of theorem "dense" changed slightly due to integration
  2003 with new class dense_linear_order.
  2004 
  2005 * Uniform lattice theory development in HOL.
  2006 
  2007     constants "meet" and "join" now named "inf" and "sup"
  2008     constant "Meet" now named "Inf"
  2009 
  2010     classes "meet_semilorder" and "join_semilorder" now named
  2011       "lower_semilattice" and "upper_semilattice"
  2012     class "lorder" now named "lattice"
  2013     class "comp_lat" now named "complete_lattice"
  2014 
  2015     Instantiation of lattice classes allows explicit definitions
  2016     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2017 
  2018   INCOMPATIBILITY.  Theorem renames:
  2019 
  2020     meet_left_le            ~> inf_le1
  2021     meet_right_le           ~> inf_le2
  2022     join_left_le            ~> sup_ge1
  2023     join_right_le           ~> sup_ge2
  2024     meet_join_le            ~> inf_sup_ord
  2025     le_meetI                ~> le_infI
  2026     join_leI                ~> le_supI
  2027     le_meet                 ~> le_inf_iff
  2028     le_join                 ~> ge_sup_conv
  2029     meet_idempotent         ~> inf_idem
  2030     join_idempotent         ~> sup_idem
  2031     meet_comm               ~> inf_commute
  2032     join_comm               ~> sup_commute
  2033     meet_leI1               ~> le_infI1
  2034     meet_leI2               ~> le_infI2
  2035     le_joinI1               ~> le_supI1
  2036     le_joinI2               ~> le_supI2
  2037     meet_assoc              ~> inf_assoc
  2038     join_assoc              ~> sup_assoc
  2039     meet_left_comm          ~> inf_left_commute
  2040     meet_left_idempotent    ~> inf_left_idem
  2041     join_left_comm          ~> sup_left_commute
  2042     join_left_idempotent    ~> sup_left_idem
  2043     meet_aci                ~> inf_aci
  2044     join_aci                ~> sup_aci
  2045     le_def_meet             ~> le_iff_inf
  2046     le_def_join             ~> le_iff_sup
  2047     join_absorp2            ~> sup_absorb2
  2048     join_absorp1            ~> sup_absorb1
  2049     meet_absorp1            ~> inf_absorb1
  2050     meet_absorp2            ~> inf_absorb2
  2051     meet_join_absorp        ~> inf_sup_absorb
  2052     join_meet_absorp        ~> sup_inf_absorb
  2053     distrib_join_le         ~> distrib_sup_le
  2054     distrib_meet_le         ~> distrib_inf_le
  2055 
  2056     add_meet_distrib_left   ~> add_inf_distrib_left
  2057     add_join_distrib_left   ~> add_sup_distrib_left
  2058     is_join_neg_meet        ~> is_join_neg_inf
  2059     is_meet_neg_join        ~> is_meet_neg_sup
  2060     add_meet_distrib_right  ~> add_inf_distrib_right
  2061     add_join_distrib_right  ~> add_sup_distrib_right
  2062     add_meet_join_distribs  ~> add_sup_inf_distribs
  2063     join_eq_neg_meet        ~> sup_eq_neg_inf
  2064     meet_eq_neg_join        ~> inf_eq_neg_sup
  2065     add_eq_meet_join        ~> add_eq_inf_sup
  2066     meet_0_imp_0            ~> inf_0_imp_0
  2067     join_0_imp_0            ~> sup_0_imp_0
  2068     meet_0_eq_0             ~> inf_0_eq_0
  2069     join_0_eq_0             ~> sup_0_eq_0
  2070     neg_meet_eq_join        ~> neg_inf_eq_sup
  2071     neg_join_eq_meet        ~> neg_sup_eq_inf
  2072     join_eq_if              ~> sup_eq_if
  2073 
  2074     mono_meet               ~> mono_inf
  2075     mono_join               ~> mono_sup
  2076     meet_bool_eq            ~> inf_bool_eq
  2077     join_bool_eq            ~> sup_bool_eq
  2078     meet_fun_eq             ~> inf_fun_eq
  2079     join_fun_eq             ~> sup_fun_eq
  2080     meet_set_eq             ~> inf_set_eq
  2081     join_set_eq             ~> sup_set_eq
  2082     meet1_iff               ~> inf1_iff
  2083     meet2_iff               ~> inf2_iff
  2084     meet1I                  ~> inf1I
  2085     meet2I                  ~> inf2I
  2086     meet1D1                 ~> inf1D1
  2087     meet2D1                 ~> inf2D1
  2088     meet1D2                 ~> inf1D2
  2089     meet2D2                 ~> inf2D2
  2090     meet1E                  ~> inf1E
  2091     meet2E                  ~> inf2E
  2092     join1_iff               ~> sup1_iff
  2093     join2_iff               ~> sup2_iff
  2094     join1I1                 ~> sup1I1
  2095     join2I1                 ~> sup2I1
  2096     join1I1                 ~> sup1I1
  2097     join2I2                 ~> sup1I2
  2098     join1CI                 ~> sup1CI
  2099     join2CI                 ~> sup2CI
  2100     join1E                  ~> sup1E
  2101     join2E                  ~> sup2E
  2102 
  2103     is_meet_Meet            ~> is_meet_Inf
  2104     Meet_bool_def           ~> Inf_bool_def
  2105     Meet_fun_def            ~> Inf_fun_def
  2106     Meet_greatest           ~> Inf_greatest
  2107     Meet_lower              ~> Inf_lower
  2108     Meet_set_def            ~> Inf_set_def
  2109 
  2110     Sup_def                 ~> Sup_Inf
  2111     Sup_bool_eq             ~> Sup_bool_def
  2112     Sup_fun_eq              ~> Sup_fun_def
  2113     Sup_set_eq              ~> Sup_set_def
  2114 
  2115     listsp_meetI            ~> listsp_infI
  2116     listsp_meet_eq          ~> listsp_inf_eq
  2117 
  2118     meet_min                ~> inf_min
  2119     join_max                ~> sup_max
  2120 
  2121 * Added syntactic class "size"; overloaded constant "size" now has
  2122 type "'a::size ==> bool"
  2123 
  2124 * Internal reorganisation of `size' of datatypes: size theorems
  2125 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2126 simplification rules by default!); theorems "prod.size" now named
  2127 "*.size".
  2128 
  2129 * Class "div" now inherits from class "times" rather than "type".
  2130 INCOMPATIBILITY.
  2131 
  2132 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2133 Linorder etc.  have disappeared; operations defined in terms of
  2134 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2135 
  2136 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2137 
  2138 * HOL-Word: New extensive library and type for generic, fixed size
  2139 machine words, with arithemtic, bit-wise, shifting and rotating
  2140 operations, reflection into int, nat, and bool lists, automation for
  2141 linear arithmetic (by automatic reflection into nat or int), including
  2142 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2143 arithmetic type classes, supporting automatic simplification of
  2144 numerals on all operations.
  2145 
  2146 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2147 
  2148 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2149 
  2150 * Code generator library theories:
  2151   - Code_Integer represents HOL integers by big integer literals in target
  2152     languages.
  2153   - Code_Char represents HOL characters by character literals in target
  2154     languages.
  2155   - Code_Char_chr like Code_Char, but also offers treatment of character
  2156     codes; includes Code_Integer.
  2157   - Executable_Set allows to generate code for finite sets using lists.
  2158   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2159     denominator).
  2160   - Executable_Real implements a subset of real numbers, namly those
  2161     representable by rational numbers.
  2162   - Efficient_Nat implements natural numbers by integers, which in general will
  2163     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2164     includes Code_Integer.
  2165   - Code_Index provides an additional datatype index which is mapped to
  2166     target-language built-in integers.
  2167   - Code_Message provides an additional datatype message_string which is isomorphic to
  2168     strings; messages are mapped to target-language strings.
  2169 
  2170 * New package for inductive predicates
  2171 
  2172   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2173 
  2174     inductive
  2175       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2176       for z_1 :: U_1 and ... and z_n :: U_m
  2177     where
  2178       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2179     | ...
  2180 
  2181   with full support for type-inference, rather than
  2182 
  2183     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2184 
  2185     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2186     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2187 
  2188     inductive "s z_1 ... z_m"
  2189     intros
  2190       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2191       ...
  2192 
  2193   For backward compatibility, there is a wrapper allowing inductive
  2194   sets to be defined with the new package via
  2195 
  2196     inductive_set
  2197       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2198       for z_1 :: U_1 and ... and z_n :: U_m
  2199     where
  2200       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2201     | ...
  2202 
  2203   or
  2204 
  2205     inductive_set
  2206       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2207       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2208       for z_1 :: U_1 and ... and z_n :: U_m
  2209     where
  2210       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2211     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2212     | ...
  2213 
  2214   if the additional syntax "p ..." is required.
  2215 
  2216   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2217   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2218 
  2219   INCOMPATIBILITIES:
  2220 
  2221   - Since declaration and definition of inductive sets or predicates
  2222     is no longer separated, abbreviations involving the newly
  2223     introduced sets or predicates must be specified together with the
  2224     introduction rules after the 'where' keyword (see above), rather
  2225     than before the actual inductive definition.
  2226 
  2227   - The variables in induction and elimination rules are now
  2228     quantified in the order of their occurrence in the introduction
  2229     rules, rather than in alphabetical order. Since this may break
  2230     some proofs, these proofs either have to be repaired, e.g. by
  2231     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2232     statements of the form
  2233 
  2234       case (rule_i a_i_1 ... a_i_{k_i})
  2235 
  2236     or the old order of quantification has to be restored by explicitly adding
  2237     meta-level quantifiers in the introduction rules, i.e.
  2238 
  2239       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2240 
  2241   - The format of the elimination rules is now
  2242 
  2243       p z_1 ... z_m x_1 ... x_n ==>
  2244         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2245         ==> ... ==> P
  2246 
  2247     for predicates and
  2248 
  2249       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2250         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2251         ==> ... ==> P
  2252 
  2253     for sets rather than
  2254 
  2255       x : s z_1 ... z_m ==>
  2256         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2257         ==> ... ==> P
  2258 
  2259     This may require terms in goals to be expanded to n-tuples
  2260     (e.g. using case_tac or simplification with the split_paired_all
  2261     rule) before the above elimination rule is applicable.
  2262 
  2263   - The elimination or case analysis rules for (mutually) inductive
  2264     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2265     list of rules "p_1_..._p_k.elims" is no longer available.
  2266 
  2267 * New package "function"/"fun" for general recursive functions,
  2268 supporting mutual and nested recursion, definitions in local contexts,
  2269 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2270 for small examples, and the separate tutorial on the function
  2271 package. The old recdef "package" is still available as before, but
  2272 users are encouraged to use the new package.
  2273 
  2274 * Method "lexicographic_order" automatically synthesizes termination
  2275 relations as lexicographic combinations of size measures. 
  2276 
  2277 * Case-expressions allow arbitrary constructor-patterns (including
  2278 "_") and take their order into account, like in functional
  2279 programming.  Internally, this is translated into nested
  2280 case-expressions; missing cases are added and mapped to the predefined
  2281 constant "undefined". In complicated cases printing may no longer show
  2282 the original input but the internal form. Lambda-abstractions allow
  2283 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2284 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2285 variable.
  2286 
  2287 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2288 is an abbreviation for "of_nat :: nat => int". The simplification
  2289 rules for "of_nat" have been changed to work like "int" did
  2290 previously.  Potential INCOMPATIBILITY:
  2291   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2292   - of_nat_diff and of_nat_mult are no longer default simp rules
  2293 
  2294 * Method "algebra" solves polynomial equations over (semi)rings using
  2295 Groebner bases. The (semi)ring structure is defined by locales and the
  2296 tool setup depends on that generic context. Installing the method for
  2297 a specific type involves instantiating the locale and possibly adding
  2298 declarations for computation on the coefficients.  The method is
  2299 already instantiated for natural numbers and for the axiomatic class
  2300 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2301 CALCULEMUS 2007 for the general principles underlying this
  2302 architecture of context-aware proof-tools.
  2303 
  2304 * Method "ferrack" implements quantifier elimination over
  2305 special-purpose dense linear orders using locales (analogous to
  2306 "algebra"). The method is already installed for class
  2307 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2308 rat, etc.
  2309 
  2310 * Former constant "List.op @" now named "List.append".  Use ML
  2311 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2312 circumvent possible incompatibilities when working on ML level.
  2313 
  2314 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2315 
  2316 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2317 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2318 
  2319 * New syntax for Haskell-like list comprehension (input only), eg.
  2320 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2321 
  2322 * The special syntax for function "filter" has changed from [x :
  2323 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2324 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2325 
  2326 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2327 defined on nat only, as an abbreviation for [a..<Suc b]
  2328 INCOMPATIBILITY.
  2329 
  2330 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2331 
  2332 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2333 
  2334 * New lemma collection field_simps (an extension of ring_simps) for
  2335 manipulating (in)equations involving division. Multiplies with all
  2336 denominators that can be proved to be non-zero (in equations) or
  2337 positive/negative (in inequations).
  2338 
  2339 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2340 have been improved and renamed to ring_simps, group_simps and
  2341 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2342 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2343 
  2344 * Theory Library/Commutative_Ring: switched from recdef to function
  2345 package; constants add, mul, pow now curried.  Infix syntax for
  2346 algebraic operations.
  2347 
  2348 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2349 INCOMPATIBILITY.
  2350 
  2351 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2352 INCOMPATIBILITY.
  2353 
  2354 * HOL/records: generalised field-update to take a function on the
  2355 field rather than the new value: r(|A := x|) is translated to A_update
  2356 (K x) r The K-combinator that is internally used is called K_record.
  2357 INCOMPATIBILITY: Usage of the plain update functions has to be
  2358 adapted.
  2359  
  2360 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2361 * x = 0, which are required for a semiring.  Richer structures do not
  2362 inherit from semiring_0 anymore, because this property is a theorem
  2363 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2364 there is more to prove, but this is mostly trivial.
  2365 
  2366 * Class "recpower" is generalized to arbitrary monoids, not just
  2367 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2368 commutativity or semiring properties additionally.
  2369 
  2370 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2371 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2372 better use 'abbreviation'.
  2373 
  2374 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2375 
  2376 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2377 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2378 significant changes for setting up numeral syntax for types:
  2379   - New constants Numeral.pred and Numeral.succ instead
  2380       of former Numeral.bin_pred and Numeral.bin_succ.
  2381   - Use integer operations instead of bin_add, bin_mult and so on.
  2382   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2383   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2384 
  2385 See src/HOL/Integ/IntArith.thy for an example setup.
  2386 
  2387 * Command 'normal_form' computes the normal form of a term that may
  2388 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2389 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2390 heavy-duty computations because the functions are compiled to ML
  2391 first.  Correspondingly, a method "normalization" is provided.  See
  2392 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2393 
  2394 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2395 25 like -->); output depends on the "iff" print_mode, the default is
  2396 "A = B" (with priority 50).
  2397 
  2398 * Relations less (<) and less_eq (<=) are also available on type bool.
  2399 Modified syntax to disallow nesting without explicit parentheses,
  2400 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2401 INCOMPATIBILITY.
  2402 
  2403 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2404 
  2405 * Relation composition operator "op O" now has precedence 75 and binds
  2406 stronger than union and intersection. INCOMPATIBILITY.
  2407 
  2408 * The old set interval syntax "{m..n(}" (and relatives) has been
  2409 removed.  Use "{m..<n}" (and relatives) instead.
  2410 
  2411 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2412 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2413 ``declare [[simproc del: neq]]''.
  2414 
  2415 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2416 True/False.
  2417 
  2418 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2419 
  2420 * Theorem setsum_mult renamed to setsum_right_distrib.
  2421 
  2422 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2423 ``rule'' method.
  2424 
  2425 * Reimplemented methods "sat" and "satx", with several improvements:
  2426 goals no longer need to be stated as "<prems> ==> False", equivalences
  2427 (i.e. "=" on type bool) are handled, variable names of the form
  2428 "lit_<n>" are no longer reserved, significant speedup.
  2429 
  2430 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2431 zChaff is still supported as well.
  2432 
  2433 * 'inductive' and 'datatype': provide projections of mutual rules,
  2434 bundled as foo_bar.inducts;
  2435 
  2436 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2437 Library.
  2438 
  2439 * Library: moved theory Accessible_Part to main HOL.
  2440 
  2441 * Library: added theory Coinductive_List of potentially infinite lists
  2442 as greatest fixed-point.
  2443 
  2444 * Library: added theory AssocList which implements (finite) maps as
  2445 association lists.
  2446 
  2447 * Method "evaluation" solves goals (i.e. a boolean expression)
  2448 efficiently by compiling it to ML.  The goal is "proved" (via an
  2449 oracle) if it evaluates to True.
  2450 
  2451 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2452 also when invoked by the simplifier.  This results in the Simplifier
  2453 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2454 Configuration option fast_arith_split_limit=0 recovers the old
  2455 behavior.
  2456 
  2457 * Support for hex (0x20) and binary (0b1001) numerals.
  2458 
  2459 * New method: reify eqs (t), where eqs are equations for an
  2460 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2461 parameter, computes a term s::'b and a list xs::'a list and proves the
  2462 theorem I xs s = t. This is also known as reification or quoting. The
  2463 resulting theorem is applied to the subgoal to substitute t with I xs
  2464 s.  If t is omitted, the subgoal itself is reified.
  2465 
  2466 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2467 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2468 where f is supposed to be a computable function (in the sense of code
  2469 generattion). The method uses reify to compute s and xs as above then
  2470 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2471 r and finally gets the theorem t = r, which is again applied to the
  2472 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2473 
  2474 * Reflection: Automatic reification now handels binding, an example is
  2475 available in src/HOL/ex/ReflectionEx.thy
  2476 
  2477 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2478 command 'statespace' that is similar to 'record', but introduces an
  2479 abstract specification based on the locale infrastructure instead of
  2480 HOL types.  This leads to extra flexibility in composing state spaces,
  2481 in particular multiple inheritance and renaming of components.
  2482 
  2483 
  2484 *** HOL-Complex ***
  2485 
  2486 * Hyperreal: Functions root and sqrt are now defined on negative real
  2487 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2488 Nonnegativity side conditions have been removed from many lemmas, so
  2489 that more subgoals may now be solved by simplification; potential
  2490 INCOMPATIBILITY.
  2491 
  2492 * Real: new type classes formalize real normed vector spaces and
  2493 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2494 and norm :: 'a => real.
  2495 
  2496 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2497 reals into other types. The overloaded constant Reals :: 'a set is now
  2498 defined as range of_real; potential INCOMPATIBILITY.
  2499 
  2500 * Real: proper support for ML code generation, including 'quickcheck'.
  2501 Reals are implemented as arbitrary precision rationals.
  2502 
  2503 * Hyperreal: Several constants that previously worked only for the
  2504 reals have been generalized, so they now work over arbitrary vector
  2505 spaces. Type annotations may need to be added in some cases; potential
  2506 INCOMPATIBILITY.
  2507 
  2508   Infinitesimal  :: ('a::real_normed_vector) star set
  2509   HFinite        :: ('a::real_normed_vector) star set
  2510   HInfinite      :: ('a::real_normed_vector) star set
  2511   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2512   monad          :: ('a::real_normed_vector) star => 'a star set
  2513   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2514   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2515   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2516   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2517   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2518   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2519   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2520   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2521   sgn            :: 'a::real_normed_vector => 'a
  2522   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2523 
  2524 * Complex: Some complex-specific constants are now abbreviations for
  2525 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2526 hnorm.  Other constants have been entirely removed in favor of the
  2527 polymorphic versions (INCOMPATIBILITY):
  2528 
  2529   approx        <-- capprox
  2530   HFinite       <-- CFinite
  2531   HInfinite     <-- CInfinite
  2532   Infinitesimal <-- CInfinitesimal
  2533   monad         <-- cmonad
  2534   galaxy        <-- cgalaxy
  2535   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2536   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2537   (ns)deriv     <-- (ns)cderiv
  2538 
  2539 
  2540 *** HOL-Algebra ***
  2541 
  2542 * Formalisation of ideals and the quotient construction over rings.
  2543 
  2544 * Order and lattice theory no longer based on records.
  2545 INCOMPATIBILITY.
  2546 
  2547 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2548 greatest_closed.  INCOMPATIBILITY.
  2549 
  2550 * Method algebra is now set up via an attribute.  For examples see
  2551 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2552 of algebraic structures.
  2553 
  2554 * Renamed theory CRing to Ring.
  2555 
  2556 
  2557 *** HOL-Nominal ***
  2558 
  2559 * Substantial, yet incomplete support for nominal datatypes (binding
  2560 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2561 src/HOL/Nominal/Examples.  Prospective users should consult
  2562 http://isabelle.in.tum.de/nominal/
  2563 
  2564 
  2565 *** ML ***
  2566 
  2567 * ML basics: just one true type int, which coincides with IntInf.int
  2568 (even on SML/NJ).
  2569 
  2570 * ML within Isar: antiquotations allow to embed statically-checked
  2571 formal entities in the source, referring to the context available at
  2572 compile-time.  For example:
  2573 
  2574 ML {* @{sort "{zero,one}"} *}
  2575 ML {* @{typ "'a => 'b"} *}
  2576 ML {* @{term "%x. x"} *}
  2577 ML {* @{prop "x == y"} *}
  2578 ML {* @{ctyp "'a => 'b"} *}
  2579 ML {* @{cterm "%x. x"} *}
  2580 ML {* @{cprop "x == y"} *}
  2581 ML {* @{thm asm_rl} *}
  2582 ML {* @{thms asm_rl} *}
  2583 ML {* @{type_name c} *}
  2584 ML {* @{type_syntax c} *}
  2585 ML {* @{const_name c} *}
  2586 ML {* @{const_syntax c} *}
  2587 ML {* @{context} *}
  2588 ML {* @{theory} *}
  2589 ML {* @{theory Pure} *}
  2590 ML {* @{theory_ref} *}
  2591 ML {* @{theory_ref Pure} *}
  2592 ML {* @{simpset} *}
  2593 ML {* @{claset} *}
  2594 ML {* @{clasimpset} *}
  2595 
  2596 The same works for sources being ``used'' within an Isar context.
  2597 
  2598 * ML in Isar: improved error reporting; extra verbosity with
  2599 ML_Context.trace enabled.
  2600 
  2601 * Pure/General/table.ML: the join operations now works via exceptions
  2602 DUP/SAME instead of type option. This is simpler in simple cases, and
  2603 admits slightly more efficient complex applications.
  2604 
  2605 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2606 use Context.generic instead of just theory.
  2607 
  2608 * Pure: datatype Context.generic joins theory/Proof.context and
  2609 provides some facilities for code that works in either kind of
  2610 context, notably GenericDataFun for uniform theory and proof data.
  2611 
  2612 * Pure: simplified internal attribute type, which is now always
  2613 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2614 local (Proof.context) attributes have been discontinued, while
  2615 minimizing code duplication. Thm.rule_attribute and
  2616 Thm.declaration_attribute build canonical attributes; see also structure
  2617 Context for further operations on Context.generic, notably
  2618 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2619 declarations and definitions.
  2620 
  2621 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2622 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2623 init only required for impure data. INCOMPATIBILITY: empty really need
  2624 to be empty (no dependencies on theory content!)
  2625 
  2626 * Pure/kernel: consts certification ignores sort constraints given in
  2627 signature declarations. (This information is not relevant to the
  2628 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2629 potential INCOMPATIBILITY.
  2630 
  2631 * Pure: axiomatic type classes are now purely definitional, with
  2632 explicit proofs of class axioms and super class relations performed
  2633 internally. See Pure/axclass.ML for the main internal interfaces --
  2634 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2635 AxClass.axiomatize_class/classrel/arity supersede
  2636 Sign.add_classes/classrel/arities.
  2637 
  2638 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2639 global/local versions on theory vs. Proof.context have been
  2640 discontinued; Attrib.syntax and Method.syntax have been adapted
  2641 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2642 attributes, methods, etc.
  2643 
  2644 * Pure: several functions of signature "... -> theory -> theory * ..."
  2645 have been reoriented to "... -> theory -> ... * theory" in order to
  2646 allow natural usage in combination with the ||>, ||>>, |-> and
  2647 fold_map combinators.
  2648 
  2649 * Pure: official theorem names (closed derivations) and additional
  2650 comments (tags) are now strictly separate.  Name hints -- which are
  2651 maintained as tags -- may be attached any time without affecting the
  2652 derivation.
  2653 
  2654 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2655 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2656 achieve the old behaviour.
  2657 
  2658 * Pure: the "Goal" constant is now called "prop", supporting a
  2659 slightly more general idea of ``protecting'' meta-level rule
  2660 statements.
  2661 
  2662 * Pure: Logic.(un)varify only works in a global context, which is now
  2663 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2664 Logic.legacy_(un)varify as temporary workaround.
  2665 
  2666 * Pure: structure Name provides scalable operations for generating
  2667 internal variable names, notably Name.variants etc.  This replaces
  2668 some popular functions from term.ML:
  2669 
  2670   Term.variant		->  Name.variant
  2671   Term.variantlist	->  Name.variant_list
  2672   Term.invent_names	->  Name.invent_list
  2673 
  2674 Note that low-level renaming rarely occurs in new code -- operations
  2675 from structure Variable are used instead (see below).
  2676 
  2677 * Pure: structure Variable provides fundamental operations for proper
  2678 treatment of fixed/schematic variables in a context.  For example,
  2679 Variable.import introduces fixes for schematics of given facts and
  2680 Variable.export reverses the effect (up to renaming) -- this replaces
  2681 various freeze_thaw operations.
  2682 
  2683 * Pure: structure Goal provides simple interfaces for
  2684 init/conclude/finish and tactical prove operations (replacing former
  2685 Tactic.prove).  Goal.prove is the canonical way to prove results
  2686 within a given context; Goal.prove_global is a degraded version for
  2687 theory level goals, including a global Drule.standard.  Note that
  2688 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2689 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2690 in a locale context).
  2691 
  2692 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2693 and type checking (Syntax.check_term etc.), with common combinations
  2694 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2695 which are considered legacy and await removal.
  2696 
  2697 * Pure/Syntax: generic interfaces for type unchecking
  2698 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2699 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2700 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2701 available for convenience, but refer to the very same operations using
  2702 a mere theory instead of a full context.
  2703 
  2704 * Isar: simplified treatment of user-level errors, using exception
  2705 ERROR of string uniformly.  Function error now merely raises ERROR,
  2706 without any side effect on output channels.  The Isar toplevel takes
  2707 care of proper display of ERROR exceptions.  ML code may use plain
  2708 handle/can/try; cat_error may be used to concatenate errors like this:
  2709 
  2710   ... handle ERROR msg => cat_error msg "..."
  2711 
  2712 Toplevel ML code (run directly or through the Isar toplevel) may be
  2713 embedded into the Isar toplevel with exception display/debug like
  2714 this:
  2715 
  2716   Isar.toplevel (fn () => ...)
  2717 
  2718 INCOMPATIBILITY, removed special transform_error facilities, removed
  2719 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2720 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2721 -- use plain ERROR instead.
  2722 
  2723 * Isar: theory setup now has type (theory -> theory), instead of a
  2724 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2725 
  2726 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2727 ProofContext.debug/verbose flags.
  2728 
  2729 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2730 theory before entering a proof state.  Transactions now always see a
  2731 quasi-functional intermediate checkpoint, both in interactive and
  2732 batch mode.
  2733 
  2734 * Isar: simplified interfaces for outer syntax.  Renamed
  2735 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2736 OuterSyntax.add_parsers -- this functionality is now included in
  2737 OuterSyntax.command etc.  INCOMPATIBILITY.
  2738 
  2739 * Simplifier: the simpset of a running simplification process now
  2740 contains a proof context (cf. Simplifier.the_context), which is the
  2741 very context that the initial simpset has been retrieved from (by
  2742 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2743 (solver, looper etc.) may depend on arbitrary proof data.
  2744 
  2745 * Simplifier.inherit_context inherits the proof context (plus the
  2746 local bounds) of the current simplification process; any simproc
  2747 etc. that calls the Simplifier recursively should do this!  Removed
  2748 former Simplifier.inherit_bounds, which is already included here --
  2749 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2750 specify an explicit context using Simplifier.context/theory_context.
  2751 
  2752 * Simplifier/Classical Reasoner: more abstract interfaces
  2753 change_simpset/claset for modifying the simpset/claset reference of a
  2754 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2755 INCOMPATIBILITY.
  2756 
  2757 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2758 "Trueprop" etc.
  2759 
  2760 
  2761 *** System ***
  2762 
  2763 * settings: the default heap location within ISABELLE_HOME_USER now
  2764 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2765 Isabelle installations.
  2766 
  2767 * isabelle-process: option -S (secure mode) disables some critical
  2768 operations, notably runtime compilation and evaluation of ML source
  2769 code.
  2770 
  2771 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2772 
  2773 * Support for parallel execution, using native multicore support of
  2774 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2775 independent theories, according to the given theory header
  2776 specifications. The maximum number of worker threads is specified via
  2777 usedir option -M or the "max-threads" setting in Proof General. A
  2778 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2779 to 6 on a 8-core machine.  User-code needs to observe certain
  2780 guidelines for thread-safe programming, see appendix A in the Isar
  2781 Implementation manual.
  2782 
  2783 
  2784 
  2785 New in Isabelle2005 (October 2005)
  2786 ----------------------------------
  2787 
  2788 *** General ***
  2789 
  2790 * Theory headers: the new header syntax for Isar theories is
  2791 
  2792   theory <name>
  2793   imports <theory1> ... <theoryN>
  2794   uses <file1> ... <fileM>
  2795   begin
  2796 
  2797 where the 'uses' part is optional.  The previous syntax
  2798 
  2799   theory <name> = <theory1> + ... + <theoryN>:
  2800 
  2801 will disappear in the next release.  Use isatool fixheaders to convert
  2802 existing theory files.  Note that there is no change in ancient
  2803 non-Isar theories now, but these will disappear soon.
  2804 
  2805 * Theory loader: parent theories can now also be referred to via
  2806 relative and absolute paths.
  2807 
  2808 * Command 'find_theorems' searches for a list of criteria instead of a
  2809 list of constants. Known criteria are: intro, elim, dest, name:string,
  2810 simp:term, and any term. Criteria can be preceded by '-' to select
  2811 theorems that do not match. Intro, elim, dest select theorems that
  2812 match the current goal, name:s selects theorems whose fully qualified
  2813 name contain s, and simp:term selects all simplification rules whose
  2814 lhs match term.  Any other term is interpreted as pattern and selects
  2815 all theorems matching the pattern. Available in ProofGeneral under
  2816 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2817 
  2818   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2819 
  2820 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2821 matching the current goal as introduction rule and not having "HOL."
  2822 in their name (i.e. not being defined in theory HOL).
  2823 
  2824 * Command 'thms_containing' has been discontinued in favour of
  2825 'find_theorems'; INCOMPATIBILITY.
  2826 
  2827 * Communication with Proof General is now 8bit clean, which means that
  2828 Unicode text in UTF-8 encoding may be used within theory texts (both
  2829 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2830 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2831 
  2832   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2833   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2834 
  2835 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2836 Classical Reasoner.  Typical big applications run around 2 times
  2837 faster.
  2838 
  2839 
  2840 *** Document preparation ***
  2841 
  2842 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2843 of raw sources.  Only those symbols that do not require additional
  2844 LaTeX packages (depending on comments in isabellesym.sty) are
  2845 displayed properly, everything else is left verbatim.  isatool display
  2846 and isatool print are used as front ends (these are subject to the
  2847 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2848 
  2849 * Command tags control specific markup of certain regions of text,
  2850 notably folding and hiding.  Predefined tags include "theory" (for
  2851 theory begin and end), "proof" for proof commands, and "ML" for
  2852 commands involving ML code; the additional tags "visible" and
  2853 "invisible" are unused by default.  Users may give explicit tag
  2854 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2855 interpretation of tags is determined by the LaTeX job during document
  2856 preparation: see option -V of isatool usedir, or options -n and -t of
  2857 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2858 \isadroptag.
  2859 
  2860 Several document versions may be produced at the same time via isatool
  2861 usedir (the generated index.html will link all of them).  Typical
  2862 specifications include ''-V document=theory,proof,ML'' to present
  2863 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2864 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2865 these parts without any formal replacement text.  The Isabelle site
  2866 default settings produce ''document'' and ''outline'' versions as
  2867 specified above.
  2868 
  2869 * Several new antiquotations:
  2870 
  2871   @{term_type term} prints a term with its type annotated;
  2872 
  2873   @{typeof term} prints the type of a term;
  2874 
  2875   @{const const} is the same as @{term const}, but checks that the
  2876   argument is a known logical constant;
  2877 
  2878   @{term_style style term} and @{thm_style style thm} print a term or
  2879   theorem applying a "style" to it
  2880 
  2881   @{ML text}
  2882 
  2883 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2884 definitions, equations, inequations etc., 'concl' printing only the
  2885 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2886 to print the specified premise.  TermStyle.add_style provides an ML
  2887 interface for introducing further styles.  See also the "LaTeX Sugar"
  2888 document practical applications.  The ML antiquotation prints
  2889 type-checked ML expressions verbatim.
  2890 
  2891 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2892 and 'text' support optional locale specification '(in loc)', which
  2893 specifies the default context for interpreting antiquotations.  For
  2894 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2895 
  2896 * Option 'locale=NAME' of antiquotations specifies an alternative
  2897 context interpreting the subsequent argument.  For example: @{thm
  2898 [locale=lattice] inf_assoc}.
  2899 
  2900 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2901 a proof context.
  2902 
  2903 * Proper output of antiquotations for theory commands involving a
  2904 proof context (such as 'locale' or 'theorem (in loc) ...').
  2905 
  2906 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2907 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2908 
  2909 * isatool usedir: new option -C (default true) controls whether option
  2910 -D should include a copy of the original document directory; -C false
  2911 prevents unwanted effects such as copying of administrative CVS data.
  2912 
  2913 
  2914 *** Pure ***
  2915 
  2916 * Considerably improved version of 'constdefs' command.  Now performs
  2917 automatic type-inference of declared constants; additional support for
  2918 local structure declarations (cf. locales and HOL records), see also
  2919 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2920 sequential dependencies of definitions within a single 'constdefs'
  2921 section; moreover, the declared name needs to be an identifier.  If
  2922 all fails, consider to fall back on 'consts' and 'defs' separately.
  2923 
  2924 * Improved indexed syntax and implicit structures.  First of all,
  2925 indexed syntax provides a notational device for subscripted
  2926 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2927 expressions.  Secondly, in a local context with structure
  2928 declarations, number indexes \<^sub>n or the empty index (default
  2929 number 1) refer to a certain fixed variable implicitly; option
  2930 show_structs controls printing of implicit structures.  Typical
  2931 applications of these concepts involve record types and locales.
  2932 
  2933 * New command 'no_syntax' removes grammar declarations (and
  2934 translations) resulting from the given syntax specification, which is
  2935 interpreted in the same manner as for the 'syntax' command.
  2936 
  2937 * 'Advanced' translation functions (parse_translation etc.) may depend
  2938 on the signature of the theory context being presently used for
  2939 parsing/printing, see also isar-ref manual.
  2940 
  2941 * Improved 'oracle' command provides a type-safe interface to turn an
  2942 ML expression of type theory -> T -> term into a primitive rule of
  2943 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2944 is already included here); see also FOL/ex/IffExample.thy;
  2945 INCOMPATIBILITY.
  2946 
  2947 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2948 before); "cI" is no longer bound, use "c.intro" instead.
  2949 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2950 axclasses vs. locales.
  2951 
  2952 * Improved internal renaming of symbolic identifiers -- attach primes
  2953 instead of base 26 numbers.
  2954 
  2955 * New flag show_question_marks controls printing of leading question
  2956 marks in schematic variable names.
  2957 
  2958 * In schematic variable names, *any* symbol following \<^isub> or
  2959 \<^isup> is now treated as part of the base name.  For example, the
  2960 following works without printing of awkward ".0" indexes:
  2961 
  2962   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2963     by simp
  2964 
  2965 * Inner syntax includes (*(*nested*) comments*).
  2966 
  2967 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2968 annotations as "(00...)".
  2969 
  2970 * Clear separation of logical types and nonterminals, where the latter
  2971 may only occur in 'syntax' specifications or type abbreviations.
  2972 Before that distinction was only partially implemented via type class
  2973 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2974 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2975 exotic syntax specifications may require further adaption
  2976 (e.g. Cube/Cube.thy).
  2977 
  2978 * Removed obsolete type class "logic", use the top sort {} instead.
  2979 Note that non-logical types should be declared as 'nonterminals'
  2980 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2981 specifications.
  2982 
  2983 * Attributes 'induct' and 'cases': type or set names may now be
  2984 locally fixed variables as well.
  2985 
  2986 * Simplifier: can now control the depth to which conditional rewriting
  2987 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2988 Limit.
  2989 
  2990 * Simplifier: simplification procedures may now take the current
  2991 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2992 interface), which is very useful for calling the Simplifier
  2993 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2994 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2995 low-level mk_simproc no longer applies Logic.varify internally, to
  2996 allow for use in a context of fixed variables.
  2997 
  2998 * thin_tac now works even if the assumption being deleted contains !!
  2999 or ==>.  More generally, erule now works even if the major premise of
  3000 the elimination rule contains !! or ==>.
  3001 
  3002 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3003 
  3004 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3005 from Pure, which contains all common declarations already.  Both
  3006 theories are defined via plain Isabelle/Isar .thy files.
  3007 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3008 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3009 use isatool fixcpure to adapt your theory and ML sources.
  3010 
  3011 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3012 selections of theorems in named facts via index ranges.
  3013 
  3014 * 'print_theorems': in theory mode, really print the difference
  3015 wrt. the last state (works for interactive theory development only),
  3016 in proof mode print all local facts (cf. 'print_facts');
  3017 
  3018 * 'hide': option '(open)' hides only base names.
  3019 
  3020 * More efficient treatment of intermediate checkpoints in interactive
  3021 theory development.
  3022 
  3023 * Code generator is now invoked via code_module (incremental code
  3024 generation) and code_library (modular code generation, ML structures
  3025 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3026 must be quoted when used as identifiers.
  3027 
  3028 * New 'value' command for reading, evaluating and printing terms using
  3029 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3030 quoted when used as identifier.
  3031 
  3032 
  3033 *** Locales ***
  3034 
  3035 * New commands for the interpretation of locale expressions in
  3036 theories (1), locales (2) and proof contexts (3).  These generate
  3037 proof obligations from the expression specification.  After the
  3038 obligations have been discharged, theorems of the expression are added
  3039 to the theory, target locale or proof context.  The synopsis of the
  3040 commands is a follows:
  3041 
  3042   (1) interpretation expr inst
  3043   (2) interpretation target < expr
  3044   (3) interpret expr inst
  3045 
  3046 Interpretation in theories and proof contexts require a parameter
  3047 instantiation of terms from the current context.  This is applied to
  3048 specifications and theorems of the interpreted expression.
  3049 Interpretation in locales only permits parameter renaming through the
  3050 locale expression.  Interpretation is smart in that interpretations
  3051 that are active already do not occur in proof obligations, neither are
  3052 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3053 inspect active interpretations of a particular locale.  For details,
  3054 see the Isar Reference manual.  Examples can be found in
  3055 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3056 
  3057 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3058 'interpret' instead.
  3059 
  3060 * New context element 'constrains' for adding type constraints to
  3061 parameters.
  3062 
  3063 * Context expressions: renaming of parameters with syntax
  3064 redeclaration.
  3065 
  3066 * Locale declaration: 'includes' disallowed.
  3067 
  3068 * Proper static binding of attribute syntax -- i.e. types / terms /
  3069 facts mentioned as arguments are always those of the locale definition
  3070 context, independently of the context of later invocations.  Moreover,
  3071 locale operations (renaming and type / term instantiation) are applied
  3072 to attribute arguments as expected.
  3073 
  3074 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3075 actual attributes; rare situations may require Attrib.attribute to
  3076 embed those attributes into Attrib.src that lack concrete syntax.
  3077 Attribute implementations need to cooperate properly with the static
  3078 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3079 Attrib.XXX_thm etc. already do the right thing without further
  3080 intervention.  Only unusual applications -- such as "where" or "of"
  3081 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3082 on the context and the facts involved -- may have to assign parsed
  3083 values to argument tokens explicitly.
  3084 
  3085 * Changed parameter management in theorem generation for long goal
  3086 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3087 theorem statement in rare situations.
  3088 
  3089 * Locale inspection command 'print_locale' omits notes elements.  Use
  3090 'print_locale!' to have them included in the output.
  3091 
  3092 
  3093 *** Provers ***
  3094 
  3095 * Provers/hypsubst.ML: improved version of the subst method, for
  3096 single-step rewriting: it now works in bound variable contexts. New is
  3097 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3098 rewrite a different subterm than the original subst method, which is
  3099 still available as 'simplesubst'.
  3100 
  3101 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3102 and quasi orders.
  3103 
  3104 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3105 reflexive-transitive closure of relations.
  3106 
  3107 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3108 limit (previously hard-coded with a value of 20) user-definable.
  3109 
  3110 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3111 is peformed already.  Object-logics merely need to finish their
  3112 initial simpset configuration as before.  INCOMPATIBILITY.
  3113 
  3114 
  3115 *** HOL ***
  3116 
  3117 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3118 
  3119   syntax (epsilon)
  3120     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3121 
  3122 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3123 and x-symbol; use option '-m epsilon' to get it actually printed.
  3124 Moreover, the mathematically important symbolic identifier \<epsilon>
  3125 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3126 
  3127 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3128 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3129 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3130 support corresponding Isar calculations.
  3131 
  3132 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3133 instead of ":".
  3134 
  3135 * theory SetInterval: changed the syntax for open intervals:
  3136 
  3137   Old       New
  3138   {..n(}    {..<n}
  3139   {)n..}    {n<..}
  3140   {m..n(}   {m..<n}
  3141   {)m..n}   {m<..n}
  3142   {)m..n(}  {m<..<n}
  3143 
  3144 The old syntax is still supported but will disappear in the next
  3145 release.  For conversion use the following Emacs search and replace
  3146 patterns (these are not perfect but work quite well):
  3147 
  3148   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3149   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3150 
  3151 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3152 equalities in commutative rings; method 'algebra' provides a generic
  3153 interface.
  3154 
  3155 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3156 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3157 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3158 be a tuple pattern.
  3159 
  3160 Some new syntax forms are available:
  3161 
  3162   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3163   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3164   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3165   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3166 
  3167 The latter form "\<Sum>x < k. e" used to be based on a separate
  3168 function "Summation", which has been discontinued.
  3169 
  3170 * theory Finite_Set: in structured induction proofs, the insert case
  3171 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3172 (insert F x)'.
  3173 
  3174 * The 'refute' command has been extended to support a much larger
  3175 fragment of HOL, including axiomatic type classes, constdefs and
  3176 typedefs, inductive datatypes and recursion.
  3177 
  3178 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3179 Requires zChaff with proof generation to be installed.  See
  3180 HOL/ex/SAT_Examples.thy for examples.
  3181 
  3182 * Datatype induction via method 'induct' now preserves the name of the
  3183 induction variable. For example, when proving P(xs::'a list) by
  3184 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3185 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3186 in unstructured proof scripts.
  3187 
  3188 * Reworked implementation of records.  Improved scalability for
  3189 records with many fields, avoiding performance problems for type
  3190 inference. Records are no longer composed of nested field types, but
  3191 of nested extension types. Therefore the record type only grows linear
  3192 in the number of extensions and not in the number of fields.  The
  3193 top-level (users) view on records is preserved.  Potential
  3194 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3195 old record representation. The type generated for a record is called
  3196 <record_name>_ext_type.
  3197 
  3198 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3199 proofs triggered by a record definition or a simproc (if
  3200 quick_and_dirty is enabled).  Definitions of large records can take
  3201 quite long.
  3202 
  3203 New simproc record_upd_simproc for simplification of multiple record
  3204 updates enabled by default.  Moreover, trivial updates are also
  3205 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3206 occasionally, since simplification is more powerful by default.
  3207 
  3208 * typedef: proper support for polymorphic sets, which contain extra
  3209 type-variables in the term.
  3210 
  3211 * Simplifier: automatically reasons about transitivity chains
  3212 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3213 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3214 old proofs break occasionally as simplification may now solve more
  3215 goals than previously.
  3216 
  3217 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3218 present.  Works for all partial orders (class "order"), in particular
  3219 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3220 just like y <= x.
  3221 
  3222 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3223 bound variable or a constant then the let is unfolded.  Otherwise
  3224 first a is simplified to b, and then f b is simplified to g. If
  3225 possible we abstract b from g arriving at "let x = b in h x",
  3226 otherwise we unfold the let and arrive at g.  The simproc can be
  3227 enabled/disabled by the reference use_let_simproc.  Potential
  3228 INCOMPATIBILITY since simplification is more powerful by default.
  3229 
  3230 * Classical reasoning: the meson method now accepts theorems as arguments.
  3231 
  3232 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3233 jobs to provide advice on the provability of subgoals.
  3234 
  3235 * Theory OrderedGroup and Ring_and_Field: various additions and
  3236 improvements to faciliate calculations involving equalities and
  3237 inequalities.
  3238 
  3239 The following theorems have been eliminated or modified
  3240 (INCOMPATIBILITY):
  3241 
  3242   abs_eq             now named abs_of_nonneg
  3243   abs_of_ge_0        now named abs_of_nonneg
  3244   abs_minus_eq       now named abs_of_nonpos
  3245   imp_abs_id         now named abs_of_nonneg
  3246   imp_abs_neg_id     now named abs_of_nonpos
  3247   mult_pos           now named mult_pos_pos
  3248   mult_pos_le        now named mult_nonneg_nonneg
  3249   mult_pos_neg_le    now named mult_nonneg_nonpos
  3250   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3251   mult_neg           now named mult_neg_neg
  3252   mult_neg_le        now named mult_nonpos_nonpos
  3253 
  3254 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3255      
  3256      zero_le_square
  3257      not_square_less_zero 
  3258 
  3259   The following lemmas have been deleted from Real/RealPow:
  3260   
  3261      realpow_zero_zero
  3262      realpow_two
  3263      realpow_less
  3264      zero_le_power
  3265      realpow_two_le
  3266      abs_realpow_two
  3267      realpow_two_abs     
  3268 
  3269 * Theory Parity: added rules for simplifying exponents.
  3270 
  3271 * Theory List:
  3272 
  3273 The following theorems have been eliminated or modified
  3274 (INCOMPATIBILITY):
  3275 
  3276   list_all_Nil       now named list_all.simps(1)
  3277   list_all_Cons      now named list_all.simps(2)
  3278   list_all_conv      now named list_all_iff
  3279   set_mem_eq         now named mem_iff
  3280 
  3281 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3282 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3283 
  3284 
  3285 *** HOL-Complex ***
  3286 
  3287 * Theory RealDef: better support for embedding natural numbers and
  3288 integers in the reals.
  3289 
  3290 The following theorems have been eliminated or modified
  3291 (INCOMPATIBILITY):
  3292 
  3293   exp_ge_add_one_self  now requires no hypotheses
  3294   real_of_int_add      reversed direction of equality (use [symmetric])
  3295   real_of_int_minus    reversed direction of equality (use [symmetric])
  3296   real_of_int_diff     reversed direction of equality (use [symmetric])
  3297   real_of_int_mult     reversed direction of equality (use [symmetric])
  3298 
  3299 * Theory RComplete: expanded support for floor and ceiling functions.
  3300 
  3301 * Theory Ln is new, with properties of the natural logarithm
  3302 
  3303 * Hyperreal: There is a new type constructor "star" for making
  3304 nonstandard types.  The old type names are now type synonyms:
  3305 
  3306   hypreal = real star
  3307   hypnat = nat star
  3308   hcomplex = complex star
  3309 
  3310 * Hyperreal: Many groups of similarly-defined constants have been
  3311 replaced by polymorphic versions (INCOMPATIBILITY):
  3312 
  3313   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3314 
  3315   starset      <-- starsetNat, starsetC
  3316   *s*          <-- *sNat*, *sc*
  3317   starset_n    <-- starsetNat_n, starsetC_n
  3318   *sn*         <-- *sNatn*, *scn*
  3319   InternalSets <-- InternalNatSets, InternalCSets
  3320 
  3321   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3322   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3323   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3324   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3325   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3326 
  3327 * Hyperreal: Many type-specific theorems have been removed in favor of
  3328 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3329 
  3330   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3331   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3332   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3333   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3334   right_minus <-- hypreal_add_minus
  3335   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3336   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3337   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3338   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3339   mult_1_right <-- hcomplex_mult_one_right
  3340   mult_zero_left <-- hcomplex_mult_zero_left
  3341   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3342   right_distrib <-- hypnat_add_mult_distrib2
  3343   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3344   right_inverse <-- hypreal_mult_inverse
  3345   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3346   order_refl <-- {hypreal,hypnat}_le_refl
  3347   order_trans <-- {hypreal,hypnat}_le_trans
  3348   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3349   order_less_le <-- {hypreal,hypnat}_less_le
  3350   linorder_linear <-- {hypreal,hypnat}_le_linear
  3351   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3352   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3353   add_nonneg_nonneg <-- hypreal_le_add_order
  3354 
  3355 * Hyperreal: Separate theorems having to do with type-specific
  3356 versions of constants have been merged into theorems that apply to the
  3357 new polymorphic constants (INCOMPATIBILITY):
  3358 
  3359   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3360   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3361   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3362   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3363   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3364   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3365   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3366   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3367   STAR_diff <-- {STAR,STARC}_diff
  3368   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3369     STARC_hcomplex_of_complex}_image_subset
  3370   starset_n_Un <-- starset{Nat,C}_n_Un
  3371   starset_n_Int <-- starset{Nat,C}_n_Int
  3372   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3373   starset_n_diff <-- starset{Nat,C}_n_diff
  3374   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3375   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3376   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3377   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3378   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3379   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3380   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3381   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3382   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3383   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3384   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3385   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3386   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3387   starfun_diff <-- starfun{C,RC,CR}_diff
  3388   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3389   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3390   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3391   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3392   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3393   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3394   starfun_Id <-- starfunC_Id
  3395   starfun_approx <-- starfun{Nat,CR}_approx
  3396   starfun_capprox <-- starfun{C,RC}_capprox
  3397   starfun_abs <-- starfunNat_rabs
  3398   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3399   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3400   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3401   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3402   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3403   starfun_add_approx <-- starfunCR_add_approx
  3404   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3405   starfun_divide <-- starfun{C,CR,RC}_divide
  3406   starfun_n <-- starfun{Nat,C}_n
  3407   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3408   starfun_n_add <-- starfun{Nat,C}_n_add
  3409   starfun_n_add_minus <-- starfunNat_n_add_minus
  3410   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3411   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3412   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3413 
  3414   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3415   star_n_minus <-- {hypreal,hcomplex}_minus
  3416   star_n_diff <-- {hypreal,hcomplex}_diff
  3417   star_n_mult <-- {hypreal,hcomplex}_mult
  3418   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3419   star_n_le <-- {hypreal,hypnat}_le
  3420   star_n_less <-- {hypreal,hypnat}_less
  3421   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3422   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3423   star_n_abs <-- hypreal_hrabs
  3424   star_n_divide <-- hcomplex_divide
  3425 
  3426   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3427   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3428   star_of_diff <-- hypreal_of_real_diff
  3429   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3430   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3431   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3432   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3433   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3434   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3435   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3436   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3437   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3438   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3439   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3440   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3441   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3442   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3443   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3444   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3445   star_of_power <-- hypreal_of_real_power
  3446   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3447 
  3448 * Hyperreal: new method "transfer" that implements the transfer
  3449 principle of nonstandard analysis. With a subgoal that mentions
  3450 nonstandard types like "'a star", the command "apply transfer"
  3451 replaces it with an equivalent one that mentions only standard types.
  3452 To be successful, all free variables must have standard types; non-
  3453 standard variables must have explicit universal quantifiers.
  3454 
  3455 * Hyperreal: A theory of Taylor series.
  3456 
  3457 
  3458 *** HOLCF ***
  3459 
  3460 * Discontinued special version of 'constdefs' (which used to support
  3461 continuous functions) in favor of the general Pure one with full
  3462 type-inference.
  3463 
  3464 * New simplification procedure for solving continuity conditions; it
  3465 is much faster on terms with many nested lambda abstractions (cubic
  3466 instead of exponential time).
  3467 
  3468 * New syntax for domain package: selector names are now optional.
  3469 Parentheses should be omitted unless argument is lazy, for example:
  3470 
  3471   domain 'a stream = cons "'a" (lazy "'a stream")
  3472 
  3473 * New command 'fixrec' for defining recursive functions with pattern
  3474 matching; defining multiple functions with mutual recursion is also
  3475 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3476 sinr, or any data constructor defined by the domain package. The given
  3477 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3478 syntax and examples.
  3479 
  3480 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3481 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3482 but the proof obligation additionally includes an admissibility
  3483 requirement. The packages generate instances of class cpo or pcpo,
  3484 with continuity and strictness theorems for Rep and Abs.
  3485 
  3486 * HOLCF: Many theorems have been renamed according to a more standard naming
  3487 scheme (INCOMPATIBILITY):
  3488 
  3489   foo_inject:  "foo$x = foo$y ==> x = y"
  3490   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3491   foo_less:    "(foo$x << foo$y) = (x << y)"
  3492   foo_strict:  "foo$UU = UU"
  3493   foo_defined: "... ==> foo$x ~= UU"
  3494   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3495 
  3496 
  3497 *** ZF ***
  3498 
  3499 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3500 including the First Isomorphism Theorem (on quotienting by the kernel
  3501 of a homomorphism).
  3502 
  3503 * ZF/Simplifier: install second copy of type solver that actually
  3504 makes use of TC rules declared to Isar proof contexts (or locales);
  3505 the old version is still required for ML proof scripts.
  3506 
  3507 
  3508 *** Cube ***
  3509 
  3510 * Converted to Isar theory format; use locales instead of axiomatic
  3511 theories.
  3512 
  3513 
  3514 *** ML ***
  3515 
  3516 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3517 for ||>, ||>>, |>>,
  3518 
  3519 * Pure/library.ML no longer defines its own option datatype, but uses
  3520 that of the SML basis, which has constructors NONE and SOME instead of
  3521 None and Some, as well as exception Option.Option instead of OPTION.
  3522 The functions the, if_none, is_some, is_none have been adapted
  3523 accordingly, while Option.map replaces apsome.
  3524 
  3525 * Pure/library.ML: the exception LIST has been given up in favour of
  3526 the standard exceptions Empty and Subscript, as well as
  3527 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3528 superceded by the standard hd and tl functions etc.
  3529 
  3530 A number of basic list functions are no longer exported to the ML
  3531 toplevel, as they are variants of predefined functions.  The following
  3532 suggests how one can translate existing code:
  3533 
  3534     rev_append xs ys = List.revAppend (xs, ys)
  3535     nth_elem (i, xs) = List.nth (xs, i)
  3536     last_elem xs = List.last xs
  3537     flat xss = List.concat xss
  3538     seq fs = List.app fs
  3539     partition P xs = List.partition P xs
  3540     mapfilter f xs = List.mapPartial f xs
  3541 
  3542 * Pure/library.ML: several combinators for linear functional
  3543 transformations, notably reverse application and composition:
  3544 
  3545   x |> f                f #> g
  3546   (x, y) |-> f          f #-> g
  3547 
  3548 * Pure/library.ML: introduced/changed precedence of infix operators:
  3549 
  3550   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3551   infix 2 ?;
  3552   infix 3 o oo ooo oooo;
  3553   infix 4 ~~ upto downto;
  3554 
  3555 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3556 infix operators.
  3557 
  3558 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3559 fold_map support linear functional transformations and nesting.  For
  3560 example:
  3561 
  3562   fold f [x1, ..., xN] y =
  3563     y |> f x1 |> ... |> f xN
  3564 
  3565   (fold o fold) f [xs1, ..., xsN] y =
  3566     y |> fold f xs1 |> ... |> fold f xsN
  3567 
  3568   fold f [x1, ..., xN] =
  3569     f x1 #> ... #> f xN
  3570 
  3571   (fold o fold) f [xs1, ..., xsN] =
  3572     fold f xs1 #> ... #> fold f xsN
  3573 
  3574 * Pure/library.ML: the following selectors on type 'a option are
  3575 available:
  3576 
  3577   the:               'a option -> 'a  (*partial*)
  3578   these:             'a option -> 'a  where 'a = 'b list
  3579   the_default: 'a -> 'a option -> 'a
  3580   the_list:          'a option -> 'a list
  3581 
  3582 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3583 basic operations for association lists, following natural argument
  3584 order; moreover the explicit equality predicate passed here avoids
  3585 potentially expensive polymorphic runtime equality checks.
  3586 The old functions may be expressed as follows:
  3587 
  3588   assoc = uncurry (AList.lookup (op =))
  3589   assocs = these oo AList.lookup (op =)
  3590   overwrite = uncurry (AList.update (op =)) o swap
  3591 
  3592 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3593 
  3594   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3595   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3596 
  3597 replacing make_keylist and keyfilter (occassionally used)
  3598 Naive rewrites:
  3599 
  3600   make_keylist = AList.make
  3601   keyfilter = AList.find (op =)
  3602 
  3603 * eq_fst and eq_snd now take explicit equality parameter, thus
  3604   avoiding eqtypes. Naive rewrites:
  3605 
  3606     eq_fst = eq_fst (op =)
  3607     eq_snd = eq_snd (op =)
  3608 
  3609 * Removed deprecated apl and apr (rarely used).
  3610   Naive rewrites:
  3611 
  3612     apl (n, op) =>>= curry op n
  3613     apr (op, m) =>>= fn n => op (n, m)
  3614 
  3615 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3616 provides a reasonably efficient light-weight implementation of sets as
  3617 lists.
  3618 
  3619 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3620 few new operations; existing lookup and update are now curried to
  3621 follow natural argument order (for use with fold etc.);
  3622 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3623 
  3624 * Pure/General: output via the Isabelle channels of
  3625 writeln/warning/error etc. is now passed through Output.output, with a
  3626 hook for arbitrary transformations depending on the print_mode
  3627 (cf. Output.add_mode -- the first active mode that provides a output
  3628 function wins).  Already formatted output may be embedded into further
  3629 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3630 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3631 accommodate easy composition of diagnostic messages etc.  Programmers
  3632 rarely need to care about Output.output or Output.raw at all, with
  3633 some notable exceptions: Output.output is required when bypassing the
  3634 standard channels (writeln etc.), or in token translations to produce
  3635 properly formatted results; Output.raw is required when capturing
  3636 already output material that will eventually be presented to the user
  3637 a second time.  For the default print mode, both Output.output and
  3638 Output.raw have no effect.
  3639 
  3640 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3641 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3642 cumulative results are displayed at the end of a batch session.
  3643 
  3644 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3645 replaced by File.platform_path and File.shell_path (with appropriate
  3646 hooks).  This provides a clean interface for unusual systems where the
  3647 internal and external process view of file names are different.
  3648 
  3649 * Pure: more efficient orders for basic syntactic entities: added
  3650 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3651 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3652 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3653 orders now -- potential INCOMPATIBILITY for code that depends on a
  3654 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3655 Library.sort_strings on result).
  3656 
  3657 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3658 fold_types traverse types/terms from left to right, observing natural
  3659 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3660 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3661 
  3662 * Pure: name spaces have been refined, with significant changes of the
  3663 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3664 to extern(_table).  The plain name entry path is superceded by a
  3665 general 'naming' context, which also includes the 'policy' to produce
  3666 a fully qualified name and external accesses of a fully qualified
  3667 name; NameSpace.extend is superceded by context dependent
  3668 Sign.declare_name.  Several theory and proof context operations modify
  3669 the naming context.  Especially note Theory.restore_naming and
  3670 ProofContext.restore_naming to get back to a sane state; note that
  3671 Theory.add_path is no longer sufficient to recover from
  3672 Theory.absolute_path in particular.
  3673 
  3674 * Pure: new flags short_names (default false) and unique_names
  3675 (default true) for controlling output of qualified names.  If
  3676 short_names is set, names are printed unqualified.  If unique_names is
  3677 reset, the name prefix is reduced to the minimum required to achieve
  3678 the original result when interning again, even if there is an overlap
  3679 with earlier declarations.
  3680 
  3681 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3682 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3683 (useful for printing error messages).  INCOMPATIBILITY.
  3684 
  3685 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3686 Theory.theory are now identified, referring to the universal
  3687 Context.theory (see Pure/context.ML).  Actual signature and theory
  3688 content is managed as theory data.  The old code and interfaces were
  3689 spread over many files and structures; the new arrangement introduces
  3690 considerable INCOMPATIBILITY to gain more clarity:
  3691 
  3692   Context -- theory management operations (name, identity, inclusion,
  3693     parents, ancestors, merge, etc.), plus generic theory data;
  3694 
  3695   Sign -- logical signature and syntax operations (declaring consts,
  3696     types, etc.), plus certify/read for common entities;
  3697 
  3698   Theory -- logical theory operations (stating axioms, definitions,
  3699     oracles), plus a copy of logical signature operations (consts,
  3700     types, etc.); also a few basic management operations (Theory.copy,
  3701     Theory.merge, etc.)
  3702 
  3703 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3704 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3705 for convenience -- they merely return the theory.
  3706 
  3707 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3708 
  3709 * Pure: the Isar proof context type is already defined early in Pure
  3710 as Context.proof (note that ProofContext.context and Proof.context are
  3711 aliases, where the latter is the preferred name).  This enables other
  3712 Isabelle components to refer to that type even before Isar is present.
  3713 
  3714 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3715 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3716 any of these kinds.  For example, Sign.intern typeK is now
  3717 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3718 Theory.hide_types.  Also note that former
  3719 Theory.hide_classes/types/consts are now
  3720 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3721 internalize their arguments!  INCOMPATIBILITY.
  3722 
  3723 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3724 datatype thmref (with constructors Name and NameSelection) instead of
  3725 plain string -- INCOMPATIBILITY;
  3726 
  3727 * Pure: cases produced by proof methods specify options, where NONE
  3728 means to remove case bindings -- INCOMPATIBILITY in
  3729 (RAW_)METHOD_CASES.
  3730 
  3731 * Pure: the following operations retrieve axioms or theorems from a
  3732 theory node or theory hierarchy, respectively:
  3733 
  3734   Theory.axioms_of: theory -> (string * term) list
  3735   Theory.all_axioms_of: theory -> (string * term) list
  3736   PureThy.thms_of: theory -> (string * thm) list
  3737   PureThy.all_thms_of: theory -> (string * thm) list
  3738 
  3739 * Pure: print_tac now outputs the goal through the trace channel.
  3740 
  3741 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3742 Reference Toplevel.debug (default false) controls detailed printing
  3743 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3744 controls execution profiling -- set to 1 for time and 2 for space
  3745 (both increase the runtime).
  3746 
  3747 * Isar session: The initial use of ROOT.ML is now always timed,
  3748 i.e. the log will show the actual process times, in contrast to the
  3749 elapsed wall-clock time that the outer shell wrapper produces.
  3750 
  3751 * Simplifier: improved handling of bound variables (nameless
  3752 representation, avoid allocating new strings).  Simprocs that invoke
  3753 the Simplifier recursively should use Simplifier.inherit_bounds to
  3754 avoid local name clashes.  Failure to do so produces warnings
  3755 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3756 for further details.
  3757 
  3758 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3759 bindings for all theorems stored within a given theory; this may help
  3760 in porting non-Isar theories to Isar ones, while keeping ML proof
  3761 scripts for the time being.
  3762 
  3763 * ML operator HTML.with_charset specifies the charset begin used for
  3764 generated HTML files.  For example:
  3765 
  3766   HTML.with_charset "utf-8" use_thy "Hebrew";
  3767   HTML.with_charset "utf-8" use_thy "Chinese";
  3768 
  3769 
  3770 *** System ***
  3771 
  3772 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3773 isabelle, isatool etc.).
  3774 
  3775 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3776 isatool doc, isatool mkdir, display_drafts etc.).
  3777 
  3778 * isatool usedir: option -f allows specification of the ML file to be
  3779 used by Isabelle; default is ROOT.ML.
  3780 
  3781 * New isatool version outputs the version identifier of the Isabelle
  3782 distribution being used.
  3783 
  3784 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3785 (containing Boolean satisfiability problems) into Isabelle/HOL
  3786 theories.
  3787 
  3788 
  3789 
  3790 New in Isabelle2004 (April 2004)
  3791 --------------------------------
  3792 
  3793 *** General ***
  3794 
  3795 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3796   Replaces linorder.ML.
  3797 
  3798 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3799   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3800   (\<a>...\<z>), are now considered normal letters, and can therefore
  3801   be used anywhere where an ASCII letter (a...zA...Z) has until
  3802   now. COMPATIBILITY: This obviously changes the parsing of some
  3803   terms, especially where a symbol has been used as a binder, say
  3804   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3805   as an identifier.  Fix it by inserting a space around former
  3806   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3807   existing theory and ML files.
  3808 
  3809 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3810 
  3811 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3812   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3813   a normal (but invisible) letter. For multiple letter subscripts repeat
  3814   \<^isub> like this: x\<^isub>1\<^isub>2.
  3815 
  3816 * Pure: There are now sub-/superscripts that can span more than one
  3817   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3818   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3819   superscript. The new control characters are not identifier parts.
  3820 
  3821 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3822   content of "..." to the latex file instead of \isacntrl... . The "..."
  3823   may consist of any printable characters excluding the end bracket >.
  3824 
  3825 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3826   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3827   declare constants "final", which prevents their being given a definition
  3828   later.  It is useful for constants whose behaviour is fixed axiomatically
  3829   rather than definitionally, such as the meta-logic connectives.
  3830 
  3831 * Pure: 'instance' now handles general arities with general sorts
  3832   (i.e. intersections of classes),
  3833 
  3834 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3835   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3836   It can be changed to alter the colors/layout of generated pages.
  3837 
  3838 
  3839 *** Isar ***
  3840 
  3841 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3842   cut_tac, subgoal_tac and thin_tac:
  3843   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3844     locales are no longer forced to write Isar proof scripts.
  3845     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3846     emulations.
  3847   - INCOMPATIBILITY: names of variables to be instantiated may no
  3848     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3849     This is consistent with the instantiation attribute "where".
  3850 
  3851 * Attributes "where" and "of":
  3852   - Now take type variables of instantiated theorem into account when reading
  3853     the instantiation string.  This fixes a bug that caused instantiated
  3854     theorems to have too special types in some circumstances.
  3855   - "where" permits explicit instantiations of type variables.
  3856 
  3857 * Calculation commands "moreover" and "also" no longer interfere with
  3858   current facts ("this"), admitting arbitrary combinations with "then"
  3859   and derived forms.
  3860 
  3861 * Locales:
  3862   - Goal statements involving the context element "includes" no longer
  3863     generate theorems with internal delta predicates (those ending on
  3864     "_axioms") in the premise.
  3865     Resolve particular premise with <locale>.intro to obtain old form.
  3866   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3867     specification and "includes" elements in goal statement.
  3868   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3869     [intro?] and [elim?] (respectively) by default.
  3870   - Experimental command for instantiation of locales in proof contexts:
  3871         instantiate <label>[<attrs>]: <loc>
  3872     Instantiates locale <loc> and adds all its theorems to the current context
  3873     taking into account their attributes.  Label and attrs are optional
  3874     modifiers, like in theorem declarations.  If present, names of
  3875     instantiated theorems are qualified with <label>, and the attributes
  3876     <attrs> are applied after any attributes these theorems might have already.
  3877       If the locale has assumptions, a chained fact of the form
  3878     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3879     are derived.  The command does not support old-style locales declared
  3880     with "locale (open)".
  3881       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3882 
  3883 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3884   (Isar) contexts.
  3885 
  3886 
  3887 *** HOL ***
  3888 
  3889 * Proof import: new image HOL4 contains the imported library from
  3890   the HOL4 system with about 2500 theorems. It is imported by
  3891   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3892   can be used like any other Isabelle image.  See
  3893   HOL/Import/HOL/README for more information.
  3894 
  3895 * Simplifier:
  3896   - Much improved handling of linear and partial orders.
  3897     Reasoners for linear and partial orders are set up for type classes
  3898     "linorder" and "order" respectively, and are added to the default simpset
  3899     as solvers.  This means that the simplifier can build transitivity chains
  3900     to solve goals from the assumptions.
  3901   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3902     of blast or auto after simplification become unnecessary because the goal
  3903     is solved by simplification already.
  3904 
  3905 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3906     all proved in axiomatic type classes for semirings, rings and fields.
  3907 
  3908 * Numerics:
  3909   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3910     now formalized using the Ring_and_Field theory mentioned above.
  3911   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3912     than before, because now they are set up once in a generic manner.
  3913   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3914     Look for the general versions in Ring_and_Field (and Power if they concern
  3915     exponentiation).
  3916 
  3917 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3918 
  3919 * Records:
  3920   - Record types are now by default printed with their type abbreviation
  3921     instead of the list of all field types. This can be configured via
  3922     the reference "print_record_type_abbr".
  3923   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3924     (not enabled by default).
  3925   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3926     EX x. x = sel r to True (not enabled by default).
  3927   - Tactic "record_split_simp_tac" to split and simplify records added.
  3928 
  3929 * 'specification' command added, allowing for definition by
  3930   specification.  There is also an 'ax_specification' command that
  3931   introduces the new constants axiomatically.
  3932 
  3933 * arith(_tac) is now able to generate counterexamples for reals as well.
  3934 
  3935 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3936 
  3937 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3938   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3939 
  3940 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3941   matrix theory to linear programming.
  3942 
  3943 * Unions and Intersections:
  3944   The latex output syntax of UN and INT has been changed
  3945   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3946   i.e. the index formulae has become a subscript.
  3947   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3948 
  3949 * Unions and Intersections over Intervals:
  3950   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3951   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3952   like in normal math, and corresponding versions for < and for intersection.
  3953 
  3954 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3955   lexicographic dictonary ordering has been added as "lexord".
  3956 
  3957 * ML: the legacy theory structures Int and List have been removed. They had
  3958   conflicted with ML Basis Library structures having the same names.
  3959 
  3960 * 'refute' command added to search for (finite) countermodels.  Only works
  3961   for a fragment of HOL.  The installation of an external SAT solver is
  3962   highly recommended.  See "HOL/Refute.thy" for details.
  3963 
  3964 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3965   formulae under an assignment of free variables to random values.
  3966   In contrast to 'refute', it can deal with inductive datatypes,
  3967   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3968   for examples.
  3969 
  3970 
  3971 *** HOLCF ***
  3972 
  3973 * Streams now come with concatenation and are part of the HOLCF image
  3974 
  3975 
  3976 
  3977 New in Isabelle2003 (May 2003)
  3978 ------------------------------
  3979 
  3980 *** General ***
  3981 
  3982 * Provers/simplifier:
  3983 
  3984   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3985     Assumptions are now subject to complete mutual simplification,
  3986     not just from left to right. The simplifier now preserves
  3987     the order of assumptions.
  3988 
  3989     Potential INCOMPATIBILITY:
  3990 
  3991     -- simp sometimes diverges where the old version did
  3992        not, e.g. invoking simp on the goal
  3993 
  3994         [| P (f x); y = x; f x = f y |] ==> Q
  3995 
  3996        now gives rise to the infinite reduction sequence
  3997 
  3998         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3999 
  4000        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4001        kind of problem.
  4002 
  4003     -- Tactics combining classical reasoner and simplification (such as auto)
  4004        are also affected by this change, because many of them rely on
  4005        simp. They may sometimes diverge as well or yield a different numbers
  4006        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4007        in case of problems. Sometimes subsequent calls to the classical
  4008        reasoner will fail because a preceeding call to the simplifier too
  4009        eagerly simplified the goal, e.g. deleted redundant premises.
  4010 
  4011   - The simplifier trace now shows the names of the applied rewrite rules
  4012 
  4013   - You can limit the number of recursive invocations of the simplifier
  4014     during conditional rewriting (where the simplifie tries to solve the
  4015     conditions before applying the rewrite rule):
  4016     ML "simp_depth_limit := n"
  4017     where n is an integer. Thus you can force termination where previously
  4018     the simplifier would diverge.
  4019 
  4020   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4021 
  4022   - No longer aborts on failed congruence proof.  Instead, the
  4023     congruence is ignored.
  4024 
  4025 * Pure: New generic framework for extracting programs from constructive
  4026   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4027   as HOL/Extraction for some case studies.
  4028 
  4029 * Pure: The main goal of the proof state is no longer shown by default, only
  4030 the subgoals. This behaviour is controlled by a new flag.
  4031    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4032 (ML: Proof.show_main_goal).
  4033 
  4034 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4035 rules whose conclusion matches subgoal 1:
  4036       PG menu: Isabelle/Isar -> Show me -> matching rules
  4037 The rules are ordered by how closely they match the subgoal.
  4038 In particular, rules that solve a subgoal outright are displayed first
  4039 (or rather last, the way they are printed).
  4040 (ML: ProofGeneral.print_intros())
  4041 
  4042 * Pure: New flag trace_unify_fail causes unification to print
  4043 diagnostic information (PG: in trace buffer) when it fails. This is
  4044 useful for figuring out why single step proofs like rule, erule or
  4045 assumption failed.
  4046 
  4047 * Pure: Locale specifications now produce predicate definitions
  4048 according to the body of text (covering assumptions modulo local
  4049 definitions); predicate "loc_axioms" covers newly introduced text,
  4050 while "loc" is cumulative wrt. all included locale expressions; the
  4051 latter view is presented only on export into the global theory
  4052 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4053 on the old view without predicates;
  4054 
  4055 * Pure: predefined locales "var" and "struct" are useful for sharing
  4056 parameters (as in CASL, for example); just specify something like
  4057 ``var x + var y + struct M'' as import;
  4058 
  4059 * Pure: improved thms_containing: proper indexing of facts instead of
  4060 raw theorems; check validity of results wrt. current name space;
  4061 include local facts of proof configuration (also covers active
  4062 locales), cover fixed variables in index; may use "_" in term
  4063 specification; an optional limit for the number of printed facts may
  4064 be given (the default is 40);
  4065 
  4066 * Pure: disallow duplicate fact bindings within new-style theory files
  4067 (batch-mode only);
  4068 
  4069 * Provers: improved induct method: assumptions introduced by case
  4070 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4071 the goal statement); "foo" still refers to all facts collectively;
  4072 
  4073 * Provers: the function blast.overloaded has been removed: all constants
  4074 are regarded as potentially overloaded, which improves robustness in exchange
  4075 for slight decrease in efficiency;
  4076 
  4077 * Provers/linorder: New generic prover for transitivity reasoning over
  4078 linear orders.  Note: this prover is not efficient!
  4079 
  4080 * Isar: preview of problems to finish 'show' now produce an error
  4081 rather than just a warning (in interactive mode);
  4082 
  4083 
  4084 *** HOL ***
  4085 
  4086 * arith(_tac)
  4087 
  4088  - Produces a counter example if it cannot prove a goal.
  4089    Note that the counter example may be spurious if the goal is not a formula
  4090    of quantifier-free linear arithmetic.
  4091    In ProofGeneral the counter example appears in the trace buffer.
  4092 
  4093  - Knows about div k and mod k where k is a numeral of type nat or int.
  4094 
  4095  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4096    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4097    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4098 
  4099 * simp's arithmetic capabilities have been enhanced a bit: it now
  4100 takes ~= in premises into account (by performing a case split);
  4101 
  4102 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4103 are distributed over a sum of terms;
  4104 
  4105 * New tactic "trans_tac" and method "trans" instantiate
  4106 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4107 "<=", "<" and "=").
  4108 
  4109 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4110 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4111 
  4112 * 'typedef' command has new option "open" to suppress the set
  4113 definition;
  4114 
  4115 * functions Min and Max on finite sets have been introduced (theory
  4116 Finite_Set);
  4117 
  4118 * attribute [symmetric] now works for relations as well; it turns
  4119 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4120 
  4121 * induct over a !!-quantified statement (say !!x1..xn):
  4122   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4123 
  4124 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4125 %x. None. Warning: empty_def now refers to the previously hidden definition
  4126 of the empty set.
  4127 
  4128 * Algebra: formalization of classical algebra.  Intended as base for
  4129 any algebraic development in Isabelle.  Currently covers group theory
  4130 (up to Sylow's theorem) and ring theory (Universal Property of
  4131 Univariate Polynomials).  Contributions welcome;
  4132 
  4133 * GroupTheory: deleted, since its material has been moved to Algebra;
  4134 
  4135 * Complex: new directory of the complex numbers with numeric constants,
  4136 nonstandard complex numbers, and some complex analysis, standard and
  4137 nonstandard (Jacques Fleuriot);
  4138 
  4139 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4140 
  4141 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4142 Fleuriot);
  4143 
  4144 * Real/HahnBanach: updated and adapted to locales;
  4145 
  4146 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4147 Gray and Kramer);
  4148 
  4149 * UNITY: added the Meier-Sanders theory of progress sets;
  4150 
  4151 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4152 as abstract algorithms, instantiated to the JVM;
  4153 
  4154 * Bali: Java source language formalization. Type system, operational
  4155 semantics, axiomatic semantics. Supported language features:
  4156 classes, interfaces, objects,virtual methods, static methods,
  4157 static/instance fields, arrays, access modifiers, definite
  4158 assignment, exceptions.
  4159 
  4160 
  4161 *** ZF ***
  4162 
  4163 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4164 universe, etc.);
  4165 
  4166 * Main ZF: virtually all theories converted to new-style format;
  4167 
  4168 
  4169 *** ML ***
  4170 
  4171 * Pure: Tactic.prove provides sane interface for internal proofs;
  4172 omits the infamous "standard" operation, so this is more appropriate
  4173 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4174 
  4175 * Pure: improved error reporting of simprocs;
  4176 
  4177 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4178 up simprocs;
  4179 
  4180 
  4181 *** Document preparation ***
  4182 
  4183 * uses \par instead of \\ for line breaks in theory text. This may
  4184 shift some page breaks in large documents. To get the old behaviour
  4185 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4186 
  4187 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4188 other packages
  4189 
  4190 * \<euro> now needs package babel/greek instead of marvosym (which
  4191 broke \Rightarrow)
  4192 
  4193 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4194 textcomp package)
  4195 
  4196 
  4197 
  4198 New in Isabelle2002 (March 2002)
  4199 --------------------------------
  4200 
  4201 *** Document preparation ***
  4202 
  4203 * greatly simplified document preparation setup, including more
  4204 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4205 instructive isatool mkdir; users should basically be able to get
  4206 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4207 users may run a separate document processing stage manually like this:
  4208 "isatool usedir -D output HOL Test && isatool document Test/output";
  4209 
  4210 * theory dependency graph may now be incorporated into documents;
  4211 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4212 with \includegraphics of LaTeX;
  4213 
  4214 * proper spacing of consecutive markup elements, especially text
  4215 blocks after section headings;
  4216 
  4217 * support bold style (for single symbols only), input syntax is like
  4218 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4219 
  4220 * \<bullet> is now output as bold \cdot by default, which looks much
  4221 better in printed text;
  4222 
  4223 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4224 note that these symbols are currently unavailable in Proof General /
  4225 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4226 
  4227 * isatool latex no longer depends on changed TEXINPUTS, instead
  4228 isatool document copies the Isabelle style files to the target
  4229 location;
  4230 
  4231 
  4232 *** Isar ***
  4233 
  4234 * Pure/Provers: improved proof by cases and induction;
  4235   - 'case' command admits impromptu naming of parameters (such as
  4236     "case (Suc n)");
  4237   - 'induct' method divinates rule instantiation from the inductive
  4238     claim; no longer requires excessive ?P bindings for proper
  4239     instantiation of cases;
  4240   - 'induct' method properly enumerates all possibilities of set/type
  4241     rules; as a consequence facts may be also passed through *type*
  4242     rules without further ado;
  4243   - 'induct' method now derives symbolic cases from the *rulified*
  4244     rule (before it used to rulify cases stemming from the internal
  4245     atomized version); this means that the context of a non-atomic
  4246     statement becomes is included in the hypothesis, avoiding the
  4247     slightly cumbersome show "PROP ?case" form;
  4248   - 'induct' may now use elim-style induction rules without chaining
  4249     facts, using ``missing'' premises from the goal state; this allows
  4250     rules stemming from inductive sets to be applied in unstructured
  4251     scripts, while still benefitting from proper handling of non-atomic
  4252     statements; NB: major inductive premises need to be put first, all
  4253     the rest of the goal is passed through the induction;
  4254   - 'induct' proper support for mutual induction involving non-atomic
  4255     rule statements (uses the new concept of simultaneous goals, see
  4256     below);
  4257   - append all possible rule selections, but only use the first
  4258     success (no backtracking);
  4259   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4260   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4261   - added 'print_induct_rules' (covered by help item in recent Proof
  4262     General versions);
  4263   - moved induct/cases attributes to Pure, methods to Provers;
  4264   - generic method setup instantiated for FOL and HOL;
  4265 
  4266 * Pure: support multiple simultaneous goal statements, for example
  4267 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4268 meta-level mechanism, this acts as if several individual goals had
  4269 been stated separately; in particular common proof methods need to be
  4270 repeated in order to cover all claims; note that a single elimination
  4271 step is *not* sufficient to establish the two conjunctions, so this
  4272 fails:
  4273 
  4274   assume "A & B" then have A and B ..   (*".." fails*)
  4275 
  4276 better use "obtain" in situations as above; alternative refer to
  4277 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4278 
  4279 * Pure: proper integration with ``locales''; unlike the original
  4280 version by Florian Kammller, Isar locales package high-level proof
  4281 contexts rather than raw logical ones (e.g. we admit to include
  4282 attributes everywhere); operations on locales include merge and
  4283 rename; support for implicit arguments (``structures''); simultaneous
  4284 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4285 some examples;
  4286 
  4287 * Pure: the following commands have been ``localized'', supporting a
  4288 target locale specification "(in name)": 'lemma', 'theorem',
  4289 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4290 stored both within the locale and at the theory level (exported and
  4291 qualified by the locale name);
  4292 
  4293 * Pure: theory goals may now be specified in ``long'' form, with
  4294 ad-hoc contexts consisting of arbitrary locale elements. for example
  4295 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4296 definitions may be given, too); the result is a meta-level rule with
  4297 the context elements being discharged in the obvious way;
  4298 
  4299 * Pure: new proof command 'using' allows to augment currently used
  4300 facts after a goal statement ('using' is syntactically analogous to
  4301 'apply', but acts on the goal's facts only); this allows chained facts
  4302 to be separated into parts given before and after a claim, as in
  4303 ``from a and b have C using d and e <proof>'';
  4304 
  4305 * Pure: renamed "antecedent" case to "rule_context";
  4306 
  4307 * Pure: new 'judgment' command records explicit information about the
  4308 object-logic embedding (used by several tools internally); no longer
  4309 use hard-wired "Trueprop";
  4310 
  4311 * Pure: added 'corollary' command;
  4312 
  4313 * Pure: fixed 'token_translation' command;
  4314 
  4315 * Pure: removed obsolete 'exported' attribute;
  4316 
  4317 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4318 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4319 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4320 
  4321 * Pure: method 'atomize' presents local goal premises as object-level
  4322 statements (atomic meta-level propositions); setup controlled via
  4323 rewrite rules declarations of 'atomize' attribute; example
  4324 application: 'induct' method with proper rule statements in improper
  4325 proof *scripts*;
  4326 
  4327 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4328 now consider the syntactic context of assumptions, giving a better
  4329 chance to get type-inference of the arguments right (this is
  4330 especially important for locales);
  4331 
  4332 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4333 mode;
  4334 
  4335 * Pure/obtain: the formal conclusion "thesis", being marked as
  4336 ``internal'', may no longer be reference directly in the text;
  4337 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4338 situations;
  4339 
  4340 * Pure: generic 'sym' attribute which declares a rule both as pure
  4341 'elim?' and for the 'symmetric' operation;
  4342 
  4343 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4344 text; the fixed correlation with particular command syntax has been
  4345 discontinued;
  4346 
  4347 * Pure: new method 'rules' is particularly well-suited for proof
  4348 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4349 but often produces more compact proof terms with less detours;
  4350 
  4351 * Pure/Provers/classical: simplified integration with pure rule
  4352 attributes and methods; the classical "intro?/elim?/dest?"
  4353 declarations coincide with the pure ones; the "rule" method no longer
  4354 includes classically swapped intros; "intro" and "elim" methods no
  4355 longer pick rules from the context; also got rid of ML declarations
  4356 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4357 INCOMPATIBILITY;
  4358 
  4359 * Provers/classical: attribute 'swapped' produces classical inversions
  4360 of introduction rules;
  4361 
  4362 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4363 rules instead of full simplifier context; 'iff' attribute handles
  4364 conditional rules;
  4365 
  4366 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4367 
  4368 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4369 "(permissive)" option to recover old behavior;
  4370 
  4371 * HOL: 'inductive' no longer features separate (collective) attributes
  4372 for 'intros' (was found too confusing);
  4373 
  4374 * HOL: properly declared induction rules less_induct and
  4375 wf_induct_rule;
  4376 
  4377 
  4378 *** HOL ***
  4379 
  4380 * HOL: moved over to sane numeral syntax; the new policy is as
  4381 follows:
  4382 
  4383   - 0 and 1 are polymorphic constants, which are defined on any
  4384   numeric type (nat, int, real etc.);
  4385 
  4386   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4387   binary representation internally;
  4388 
  4389   - type nat has special constructor Suc, and generally prefers Suc 0
  4390   over 1::nat and Suc (Suc 0) over 2::nat;
  4391 
  4392 This change may cause significant problems of INCOMPATIBILITY; here
  4393 are some hints on converting existing sources:
  4394 
  4395   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4396   entities, so expressions involving "-" (unary or binary minus) need
  4397   to be spaced properly;
  4398 
  4399   - existing occurrences of "1" may need to be constraint "1::nat" or
  4400   even replaced by Suc 0; similar for old "2";
  4401 
  4402   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4403 
  4404   - remove all special provisions on numerals in proofs;
  4405 
  4406 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4407 representation (depends on bin_arith_simps in the default context);
  4408 
  4409 * HOL: symbolic syntax for x^2 (numeral 2);
  4410 
  4411 * HOL: the class of all HOL types is now called "type" rather than
  4412 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4413 in axclass/classes, instance/arities, and (usually rare) occurrences
  4414 in typings (of consts etc.); internally the class is called
  4415 "HOL.type", ML programs should refer to HOLogic.typeS;
  4416 
  4417 * HOL/record package improvements:
  4418   - new derived operations "fields" to build a partial record section,
  4419     "extend" to promote a fixed record to a record scheme, and
  4420     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4421     declared as simp by default;
  4422   - shared operations ("more", "fields", etc.) now need to be always
  4423     qualified) --- potential INCOMPATIBILITY;
  4424   - removed "make_scheme" operations (use "make" with "extend") --
  4425     INCOMPATIBILITY;
  4426   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4427   - provides cases/induct rules for use with corresponding Isar
  4428     methods (for concrete records, record schemes, concrete more
  4429     parts, and schematic more parts -- in that order);
  4430   - internal definitions directly based on a light-weight abstract
  4431     theory of product types over typedef rather than datatype;
  4432 
  4433 * HOL: generic code generator for generating executable ML code from
  4434 specifications; specific support for HOL constructs such as inductive
  4435 datatypes and sets, as well as recursive functions; can be invoked
  4436 via 'generate_code' theory section;
  4437 
  4438 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4439 
  4440 * HOL: consolidated and renamed several theories.  In particular:
  4441         Ord.thy has been absorbed into HOL.thy
  4442         String.thy has been absorbed into List.thy
  4443 
  4444 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4445 (beware of argument permutation!);
  4446 
  4447 * HOL: linorder_less_split superseded by linorder_cases;
  4448 
  4449 * HOL/List: "nodups" renamed to "distinct";
  4450 
  4451 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4452 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4453   - Ex_def has changed, now need to use some_eq_ex
  4454 
  4455 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4456 in this (rare) case use:
  4457 
  4458   delSWrapper "split_all_tac"
  4459   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4460 
  4461 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4462 MAY FAIL;
  4463 
  4464 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4465 Isabelle's type classes, ^ on functions and relations has too general
  4466 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4467 necessary to attach explicit type constraints;
  4468 
  4469 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4470 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4471 renamed accordingly (eg "compI" -> "rel_compI").
  4472 
  4473 * HOL: syntax translations now work properly with numerals and records
  4474 expressions;
  4475 
  4476 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4477 of "lam" -- INCOMPATIBILITY;
  4478 
  4479 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4480 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4481 renamed "Product_Type.unit";
  4482 
  4483 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4484 
  4485 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4486 the "cases" method);
  4487 
  4488 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4489 Florian Kammller);
  4490 
  4491 * HOL/IMP: updated and converted to new-style theory format; several
  4492 parts turned into readable document, with proper Isar proof texts and
  4493 some explanations (by Gerwin Klein);
  4494 
  4495 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4496 
  4497 * HOL-Hyperreal is now a logic image;
  4498 
  4499 
  4500 *** HOLCF ***
  4501 
  4502 * Isar: consts/constdefs supports mixfix syntax for continuous
  4503 operations;
  4504 
  4505 * Isar: domain package adapted to new-style theory format, e.g. see
  4506 HOLCF/ex/Dnat.thy;
  4507 
  4508 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4509 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4510 lift.induct_tac, always use UU instead of Undef;
  4511 
  4512 * HOLCF/IMP: updated and converted to new-style theory;
  4513 
  4514 
  4515 *** ZF ***
  4516 
  4517 * Isar: proper integration of logic-specific tools and packages,
  4518 including theory commands '(co)inductive', '(co)datatype',
  4519 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4520 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4521 
  4522 * theory Main no longer includes AC; for the Axiom of Choice, base
  4523 your theory on Main_ZFC;
  4524 
  4525 * the integer library now covers quotients and remainders, with many
  4526 laws relating division to addition, multiplication, etc.;
  4527 
  4528 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4529 typeless version of the formalism;
  4530 
  4531 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4532 format;
  4533 
  4534 * ZF/Induct: new directory for examples of inductive definitions,
  4535 including theory Multiset for multiset orderings; converted to
  4536 new-style theory format;
  4537 
  4538 * ZF: many new theorems about lists, ordinals, etc.;
  4539 
  4540 
  4541 *** General ***
  4542 
  4543 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4544 variable proof controls level of detail: 0 = no proofs (only oracle
  4545 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4546 also ref manual for further ML interfaces;
  4547 
  4548 * Pure/axclass: removed obsolete ML interface
  4549 goal_subclass/goal_arity;
  4550 
  4551 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4552 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4553 separate tokens, so expressions involving minus need to be spaced
  4554 properly;
  4555 
  4556 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4557 rather than "infixl" or "infixr";
  4558 
  4559 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4560 sort constraint specifications in type inference; e.g. "x::_::foo"
  4561 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4562 type variable);
  4563 
  4564 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4565 control output of nested => (types); the default behavior is
  4566 "type_brackets";
  4567 
  4568 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4569 tokens into AST constants;
  4570 
  4571 * Pure/syntax: prefer later declarations of translations and print
  4572 translation functions; potential INCOMPATIBILITY: need to reverse
  4573 multiple declarations for same syntax element constant;
  4574 
  4575 * Pure/show_hyps reset by default (in accordance to existing Isar
  4576 practice);
  4577 
  4578 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4579 addSafter;
  4580 
  4581 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4582 as well;
  4583 
  4584 * system: tested support for MacOS X; should be able to get Isabelle +
  4585 Proof General to work in a plain Terminal after installing Poly/ML
  4586 (e.g. from the Isabelle distribution area) and GNU bash alone
  4587 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4588 support requires further installations, e.g. from
  4589 http://fink.sourceforge.net/);
  4590 
  4591 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4592 
  4593 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4594 of 40 MB), cf. ML_OPTIONS;
  4595 
  4596 * system: Proof General keywords specification is now part of the
  4597 Isabelle distribution (see etc/isar-keywords.el);
  4598 
  4599 * system: support for persistent Proof General sessions (refrain from
  4600 outdating all loaded theories on startup); user may create writable
  4601 logic images like this: ``isabelle -q HOL Test'';
  4602 
  4603 * system: smart selection of Isabelle process versus Isabelle
  4604 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4605 run both "isabelle" and "Isabelle" even if file names are badly
  4606 damaged (executable inspects the case of the first letter of its own
  4607 name); added separate "isabelle-process" and "isabelle-interface";
  4608 
  4609 * system: refrain from any attempt at filtering input streams; no
  4610 longer support ``8bit'' encoding of old isabelle font, instead proper
  4611 iso-latin characters may now be used; the related isatools
  4612 "symbolinput" and "nonascii" have disappeared as well;
  4613 
  4614 * system: removed old "xterm" interface (the print modes "xterm" and
  4615 "xterm_color" are still available for direct use in a suitable
  4616 terminal);
  4617 
  4618 
  4619 
  4620 New in Isabelle99-2 (February 2001)
  4621 -----------------------------------
  4622 
  4623 *** Overview of INCOMPATIBILITIES ***
  4624 
  4625 * HOL: please note that theories in the Library and elsewhere often use the
  4626 new-style (Isar) format; to refer to their theorems in an ML script you must
  4627 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4628 
  4629 * HOL: inductive package no longer splits induction rule aggressively,
  4630 but only as far as specified by the introductions given; the old
  4631 format may be recovered via ML function complete_split_rule or attribute
  4632 'split_rule (complete)';
  4633 
  4634 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4635 gfp_Tarski to gfp_unfold;
  4636 
  4637 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4638 
  4639 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4640 relation); infix "^^" has been renamed "``"; infix "``" has been
  4641 renamed "`"; "univalent" has been renamed "single_valued";
  4642 
  4643 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4644 operation;
  4645 
  4646 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4647 
  4648 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4649 
  4650 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4651 consequence, it is no longer monotonic wrt. the local goal context
  4652 (which is now passed through the inductive cases);
  4653 
  4654 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4655 \<gg> to \<ggreater>;
  4656 
  4657 
  4658 *** Document preparation ***
  4659 
  4660 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4661 available: are "it" for near math-mode best-style output, "sl" for
  4662 slanted text style, and "tt" for plain type-writer; if no
  4663 \isabellestyle command is given, output is according to slanted
  4664 type-writer);
  4665 
  4666 * support sub/super scripts (for single symbols only), input syntax is
  4667 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4668 
  4669 * some more standard symbols; see Appendix A of the system manual for
  4670 the complete list of symbols defined in isabellesym.sty;
  4671 
  4672 * improved isabelle style files; more abstract symbol implementation
  4673 (should now use \isamath{...} and \isatext{...} in custom symbol
  4674 definitions);
  4675 
  4676 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4677 state; Note that presentation of goal states does not conform to
  4678 actual human-readable proof documents.  Please do not include goal
  4679 states into document output unless you really know what you are doing!
  4680 
  4681 * proper indentation of antiquoted output with proportional LaTeX
  4682 fonts;
  4683 
  4684 * no_document ML operator temporarily disables LaTeX document
  4685 generation;
  4686 
  4687 * isatool unsymbolize tunes sources for plain ASCII communication;
  4688 
  4689 
  4690 *** Isar ***
  4691 
  4692 * Pure: Isar now suffers initial goal statements to contain unbound
  4693 schematic variables (this does not conform to actual readable proof
  4694 documents, due to unpredictable outcome and non-compositional proof
  4695 checking); users who know what they are doing may use schematic goals
  4696 for Prolog-style synthesis of proven results;
  4697 
  4698 * Pure: assumption method (an implicit finishing) now handles actual
  4699 rules as well;
  4700 
  4701 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4702 initial goal, declare "that" only as Pure intro (only for single
  4703 steps); the "that" rule assumption may now be involved in implicit
  4704 finishing, thus ".." becomes a feasible for trivial obtains;
  4705 
  4706 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4707 instance proofs may be performed by "..";
  4708 
  4709 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4710 statements as well;
  4711 
  4712 * Pure: more robust selection of calculational rules;
  4713 
  4714 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4715 rule (as well as the assumption rule);
  4716 
  4717 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4718 lemmas, using the graph browser tool;
  4719 
  4720 * Pure: predict failure of "show" in interactive mode;
  4721 
  4722 * Pure: 'thms_containing' now takes actual terms as arguments;
  4723 
  4724 * HOL: improved method 'induct' --- now handles non-atomic goals
  4725 (potential INCOMPATIBILITY); tuned error handling;
  4726 
  4727 * HOL: cases and induct rules now provide explicit hints about the
  4728 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4729 any remaining facts are inserted into the goal verbatim;
  4730 
  4731 * HOL: local contexts (aka cases) may now contain term bindings as
  4732 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4733 the result to be shown in each case;
  4734 
  4735 * HOL: added 'recdef_tc' command;
  4736 
  4737 * isatool convert assists in eliminating legacy ML scripts;
  4738 
  4739 
  4740 *** HOL ***
  4741 
  4742 * HOL/Library: a collection of generic theories to be used together
  4743 with main HOL; the theory loader path already includes this directory
  4744 by default; the following existing theories have been moved here:
  4745 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4746 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4747 
  4748 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4749 modelling and verification task performed in Isabelle/HOL +
  4750 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4751 
  4752 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4753 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4754 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4755 'domain', this makes the theory consistent with mathematical
  4756 literature;
  4757 
  4758 * HOL basics: added overloaded operations "inverse" and "divide"
  4759 (infix "/"), syntax for generic "abs" operation, generic summation
  4760 operator \<Sum>;
  4761 
  4762 * HOL/typedef: simplified package, provide more useful rules (see also
  4763 HOL/subset.thy);
  4764 
  4765 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4766 now expressed as a proper nested rule (old-style tactic scripts may
  4767 require atomize_strip_tac to cope with non-atomic premises);
  4768 
  4769 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4770 to "split_conv" (old name still available for compatibility);
  4771 
  4772 * HOL: improved concrete syntax for strings (e.g. allows translation
  4773 rules with string literals);
  4774 
  4775 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4776  and Fleuriot's mechanization of analysis, including the transcendental
  4777  functions for the reals;
  4778 
  4779 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4780 
  4781 
  4782 *** CTT ***
  4783 
  4784 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4785 "lam" is displayed as TWO lambda-symbols
  4786 
  4787 * CTT: theory Main now available, containing everything (that is, Bool
  4788 and Arith);
  4789 
  4790 
  4791 *** General ***
  4792 
  4793 * Pure: the Simplifier has been implemented properly as a derived rule
  4794 outside of the actual kernel (at last!); the overall performance
  4795 penalty in practical applications is about 50%, while reliability of
  4796 the Isabelle inference kernel has been greatly improved;
  4797 
  4798 * print modes "brackets" and "no_brackets" control output of nested =>
  4799 (types) and ==> (props); the default behaviour is "brackets";
  4800 
  4801 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4802 as assumptions as well;
  4803 
  4804 * system: support Poly/ML 4.0;
  4805 
  4806 * system: isatool install handles KDE version 1 or 2;
  4807 
  4808 
  4809 
  4810 New in Isabelle99-1 (October 2000)
  4811 ----------------------------------
  4812 
  4813 *** Overview of INCOMPATIBILITIES ***
  4814 
  4815 * HOL: simplification of natural numbers is much changed; to partly
  4816 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4817 issue the following ML commands:
  4818 
  4819   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4820   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4821 
  4822 * HOL: simplification no longer dives into case-expressions; this is
  4823 controlled by "t.weak_case_cong" for each datatype t;
  4824 
  4825 * HOL: nat_less_induct renamed to less_induct;
  4826 
  4827 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4828 fixsome to patch .thy and .ML sources automatically;
  4829 
  4830   select_equality  -> some_equality
  4831   select_eq_Ex     -> some_eq_ex
  4832   selectI2EX       -> someI2_ex
  4833   selectI2         -> someI2
  4834   selectI          -> someI
  4835   select1_equality -> some1_equality
  4836   Eps_sym_eq       -> some_sym_eq_trivial
  4837   Eps_eq           -> some_eq_trivial
  4838 
  4839 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4840 
  4841 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4842 instead);
  4843 
  4844 * HOL: the recursion equations generated by 'recdef' are now called
  4845 f.simps instead of f.rules;
  4846 
  4847 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4848 
  4849 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4850 sometimes be needed;
  4851 
  4852 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4853 
  4854 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4855 
  4856 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4857 product is now "<*>" instead of "Times"; the lexicographic product is
  4858 now "<*lex*>" instead of "**";
  4859 
  4860 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4861 of main HOL, but was unused); better use HOL's datatype package;
  4862 
  4863 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4864 the old syntax may be recovered as follows:
  4865 
  4866   syntax (symbols)
  4867     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4868       (infixl "\\<oplus>" 100)
  4869 
  4870 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4871 
  4872 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4873 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4874 internally;
  4875 
  4876 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4877 changed from A/r to A//r;
  4878 
  4879 * ZF: new treatment of arithmetic (nat & int) may break some old
  4880 proofs;
  4881 
  4882 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4883 rulify -> rule_format, elimify -> elim_format, ...);
  4884 
  4885 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4886 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4887 should have to change intro!! to intro? only); replaced "delrule" by
  4888 "rule del";
  4889 
  4890 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4891 
  4892 * Provers: strengthened force_tac by using new first_best_tac;
  4893 
  4894 * LaTeX document preparation: several changes of isabelle.sty (see
  4895 lib/texinputs);
  4896 
  4897 
  4898 *** Document preparation ***
  4899 
  4900 * formal comments (text blocks etc.) in new-style theories may now
  4901 contain antiquotations of thm/prop/term/typ/text to be presented
  4902 according to latex print mode; concrete syntax is like this:
  4903 @{term[show_types] "f(x) = a + x"};
  4904 
  4905 * isatool mkdir provides easy setup of Isabelle session directories,
  4906 including proper document sources;
  4907 
  4908 * generated LaTeX sources are now deleted after successful run
  4909 (isatool document -c); may retain a copy somewhere else via -D option
  4910 of isatool usedir;
  4911 
  4912 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4913 style files, achieving self-contained LaTeX sources and simplifying
  4914 LaTeX debugging;
  4915 
  4916 * old-style theories now produce (crude) LaTeX output as well;
  4917 
  4918 * browser info session directories are now self-contained (may be put
  4919 on WWW server seperately); improved graphs of nested sessions; removed
  4920 graph for 'all sessions';
  4921 
  4922 * several improvements in isabelle style files; \isabellestyle{it}
  4923 produces fake math mode output; \isamarkupheader is now \section by
  4924 default; see lib/texinputs/isabelle.sty etc.;
  4925 
  4926 
  4927 *** Isar ***
  4928 
  4929 * Isar/Pure: local results and corresponding term bindings are now
  4930 subject to Hindley-Milner polymorphism (similar to ML); this
  4931 accommodates incremental type-inference very nicely;
  4932 
  4933 * Isar/Pure: new derived language element 'obtain' supports
  4934 generalized existence reasoning;
  4935 
  4936 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4937 support accumulation of results, without applying any rules yet;
  4938 useful to collect intermediate results without explicit name
  4939 references, and for use with transitivity rules with more than 2
  4940 premises;
  4941 
  4942 * Isar/Pure: scalable support for case-analysis type proofs: new
  4943 'case' language element refers to local contexts symbolically, as
  4944 produced by certain proof methods; internally, case names are attached
  4945 to theorems as "tags";
  4946 
  4947 * Isar/Pure: theory command 'hide' removes declarations from
  4948 class/type/const name spaces;
  4949 
  4950 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4951 indicate potential overloading;
  4952 
  4953 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4954 
  4955 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4956 "{a,b,c}" instead of {a,b,c};
  4957 
  4958 * Isar/Pure now provides its own version of intro/elim/dest
  4959 attributes; useful for building new logics, but beware of confusion
  4960 with the version in Provers/classical;
  4961 
  4962 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4963 case name 'antecedent';
  4964 
  4965 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4966 to the current context is now done automatically);
  4967 
  4968 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4969 for definining proof methods in ML;
  4970 
  4971 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4972 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4973 most cases, one should have to change intro!! to intro? only);
  4974 replaced "delrule" by "rule del";
  4975 
  4976 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4977 'symmetric' attribute (the latter supercedes [RS sym]);
  4978 
  4979 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4980 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4981 well (including splits);
  4982 
  4983 * Isar/Provers: Simplifier and Classical methods now support all kind
  4984 of modifiers used in the past, including 'cong', 'iff', etc.
  4985 
  4986 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4987 of Simplifier and Classical reasoner);
  4988 
  4989 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4990 now support named cases; major packages (inductive, datatype, primrec,
  4991 recdef) support case names and properly name parameters;
  4992 
  4993 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4994 monotonicity conditions are extracted to be proven at end of
  4995 calculations;
  4996 
  4997 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4998 method anyway;
  4999 
  5000 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5001 split_if split_if_asm; datatype package provides theorems foo.splits =
  5002 foo.split foo.split_asm for each datatype;
  5003 
  5004 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5005 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5006 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5007 use "(cases (simplified))" method in proper proof texts);
  5008 
  5009 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5010 
  5011 * Isar: names of theorems etc. may be natural numbers as well;
  5012 
  5013 * Isar: 'pr' command: optional arguments for goals_limit and
  5014 ProofContext.prems_limit; no longer prints theory contexts, but only
  5015 proof states;
  5016 
  5017 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5018 additional print modes to be specified; e.g. "pr(latex)" will print
  5019 proof state according to the Isabelle LaTeX style;
  5020 
  5021 * Isar: improved support for emulating tactic scripts, including proof
  5022 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5023 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5024 (for HOL datatypes);
  5025 
  5026 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5027 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5028 'proof method scripts' have to be in depth-first order;
  5029 
  5030 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5031 
  5032 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5033 should instead use individual commands for printing items
  5034 (print_commands, print_methods etc.);
  5035 
  5036 * Isar: added 'nothing' --- the empty list of theorems;
  5037 
  5038 
  5039 *** HOL ***
  5040 
  5041 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5042 corresponding virtual machine and a specification of its bytecode
  5043 verifier and a lightweight bytecode verifier, including proofs of
  5044 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5045 Cornelia Pusch (see also the homepage of project Bali at
  5046 http://isabelle.in.tum.de/Bali/);
  5047 
  5048 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5049 Clemens Ballarin;
  5050 
  5051 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5052 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5053 Rasmussen;
  5054 
  5055 * HOL/Lattice: fundamental concepts of lattice theory and order
  5056 structures, including duals, properties of bounds versus algebraic
  5057 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5058 Theorem for complete lattices etc.; may also serve as a demonstration
  5059 for abstract algebraic reasoning using axiomatic type classes, and
  5060 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5061 
  5062 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5063 von Oheimb;
  5064 
  5065 * HOL/IMPP: extension of IMP with local variables and mutually
  5066 recursive procedures, by David von Oheimb;
  5067 
  5068 * HOL/Lambda: converted into new-style theory and document;
  5069 
  5070 * HOL/ex/Multiquote: example of multiple nested quotations and
  5071 anti-quotations -- basically a generalized version of de-Bruijn
  5072 representation; very useful in avoiding lifting of operations;
  5073 
  5074 * HOL/record: added general record equality rule to simpset; fixed
  5075 select-update simplification procedure to handle extended records as
  5076 well; admit "r" as field name;
  5077 
  5078 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5079 other numeric types and also as the identity of groups, rings, etc.;
  5080 
  5081 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5082 Types nat and int belong to this axclass;
  5083 
  5084 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5085    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5086    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5087   two terms #m*u and #n*u are replaced by #(m+n)*u
  5088     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5089   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5090     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5091 
  5092 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5093 powerful prover for predicate logic but knows nothing of clasets; see
  5094 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5095 
  5096 * HOL: new version of "case_tac" subsumes both boolean case split and
  5097 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5098 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5099 
  5100 * HOL: simplification no longer dives into case-expressions: only the
  5101 selector expression is simplified, but not the remaining arms; to
  5102 enable full simplification of case-expressions for datatype t, you may
  5103 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5104 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5105 
  5106 * HOL/recdef: the recursion equations generated by 'recdef' for
  5107 function 'f' are now called f.simps instead of f.rules; if all
  5108 termination conditions are proved automatically, these simplification
  5109 rules are added to the simpset, as in primrec; rules may be named
  5110 individually as well, resulting in a separate list of theorems for
  5111 each equation;
  5112 
  5113 * HOL/While is a new theory that provides a while-combinator. It
  5114 permits the definition of tail-recursive functions without the
  5115 provision of a termination measure. The latter is necessary once the
  5116 invariant proof rule for while is applied.
  5117 
  5118 * HOL: new (overloaded) notation for the set of elements below/above
  5119 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5120 
  5121 * HOL: theorems impI, allI, ballI bound as "strip";
  5122 
  5123 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5124 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5125 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5126 
  5127 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5128 
  5129 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5130 main HOL, but was unused);
  5131 
  5132 * HOL: fewer consts declared as global (e.g. have to refer to
  5133 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5134 
  5135 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5136 in case of overlap with user translations (e.g. judgements over
  5137 tuples); (note that the underlying logical represenation is still
  5138 bogus);
  5139 
  5140 
  5141 *** ZF ***
  5142 
  5143 * ZF: simplification automatically cancels common terms in arithmetic
  5144 expressions over nat and int;
  5145 
  5146 * ZF: new treatment of nat to minimize type-checking: all operators
  5147 coerce their operands to a natural number using the function natify,
  5148 making the algebraic laws unconditional;
  5149 
  5150 * ZF: as above, for int: operators coerce their operands to an integer
  5151 using the function intify;
  5152 
  5153 * ZF: the integer library now contains many of the usual laws for the
  5154 orderings, including $<=, and monotonicity laws for $+ and $*;
  5155 
  5156 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5157 simplification;
  5158 
  5159 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5160 to the simplifier and classical reasoner simultaneously;
  5161 
  5162 
  5163 *** General ***
  5164 
  5165 * Provers: blast_tac now handles actual object-logic rules as
  5166 assumptions; note that auto_tac uses blast_tac internally as well;
  5167 
  5168 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5169 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5170 
  5171 * Provers: delrules now handles destruct rules as well (no longer need
  5172 explicit make_elim);
  5173 
  5174 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5175   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5176 use instead the strong form,
  5177   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5178 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5179 from destruct-rules;
  5180 
  5181 * Provers: Simplifier.easy_setup provides a fast path to basic
  5182 Simplifier setup for new object-logics;
  5183 
  5184 * Pure: AST translation rules no longer require constant head on LHS;
  5185 
  5186 * Pure: improved name spaces: ambiguous output is qualified; support
  5187 for hiding of names;
  5188 
  5189 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5190 XSYMBOL_HOME; no longer need to do manual configuration in most
  5191 situations;
  5192 
  5193 * system: compression of ML heaps images may now be controlled via -c
  5194 option of isabelle and isatool usedir (currently only observed by
  5195 Poly/ML);
  5196 
  5197 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5198 useful for remote X11);
  5199 
  5200 * system: provide TAGS file for Isabelle sources;
  5201 
  5202 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5203 order;
  5204 
  5205 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5206 timing flag supersedes proof_timing and Toplevel.trace;
  5207 
  5208 * ML: new combinators |>> and |>>> for incremental transformations
  5209 with secondary results (e.g. certain theory extensions):
  5210 
  5211 * ML: PureThy.add_defs gets additional argument to indicate potential
  5212 overloading (usually false);
  5213 
  5214 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5215 results;
  5216 
  5217 
  5218 
  5219 New in Isabelle99 (October 1999)
  5220 --------------------------------
  5221 
  5222 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5223 
  5224 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5225 are no longer simplified.  (This allows the simplifier to unfold recursive
  5226 functional programs.)  To restore the old behaviour, declare
  5227 
  5228     Delcongs [if_weak_cong];
  5229 
  5230 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5231 complement;
  5232 
  5233 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5234 
  5235 * HOL/datatype: mutual_induct_tac no longer exists --
  5236   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5237 
  5238 * HOL/typedef: fixed type inference for representing set; type
  5239 arguments now have to occur explicitly on the rhs as type constraints;
  5240 
  5241 * ZF: The con_defs part of an inductive definition may no longer refer
  5242 to constants declared in the same theory;
  5243 
  5244 * HOL, ZF: the function mk_cases, generated by the inductive
  5245 definition package, has lost an argument.  To simplify its result, it
  5246 uses the default simpset instead of a supplied list of theorems.
  5247 
  5248 * HOL/List: the constructors of type list are now Nil and Cons;
  5249 
  5250 * Simplifier: the type of the infix ML functions
  5251         setSSolver addSSolver setSolver addSolver
  5252 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5253 for packaging solvers. A solver is created via
  5254         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5255 where the string argument is only a comment.
  5256 
  5257 
  5258 *** Proof tools ***
  5259 
  5260 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5261 decision procedure for linear arithmetic. Currently it is used for
  5262 types `nat', `int', and `real' in HOL (see below); it can, should and
  5263 will be instantiated for other types and logics as well.
  5264 
  5265 * The simplifier now accepts rewrite rules with flexible heads, eg
  5266      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5267   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5268   matching.
  5269 
  5270 
  5271 *** General ***
  5272 
  5273 * New Isabelle/Isar subsystem provides an alternative to traditional
  5274 tactical theorem proving; together with the ProofGeneral/isar user
  5275 interface it offers an interactive environment for developing human
  5276 readable proof documents (Isar == Intelligible semi-automated
  5277 reasoning); for further information see isatool doc isar-ref,
  5278 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5279 
  5280 * improved and simplified presentation of theories: better HTML markup
  5281 (including colors), graph views in several sizes; isatool usedir now
  5282 provides a proper interface for user theories (via -P option); actual
  5283 document preparation based on (PDF)LaTeX is available as well (for
  5284 new-style theories only); see isatool doc system for more information;
  5285 
  5286 * native support for Proof General, both for classic Isabelle and
  5287 Isabelle/Isar;
  5288 
  5289 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5290 using the graph browser tool;
  5291 
  5292 * Isabelle manuals now also available as PDF;
  5293 
  5294 * theory loader rewritten from scratch (may not be fully
  5295 bug-compatible); old loadpath variable has been replaced by show_path,
  5296 add_path, del_path, reset_path functions; new operations such as
  5297 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5298 isatool doc ref);
  5299 
  5300 * improved isatool install: option -k creates KDE application icon,
  5301 option -p DIR installs standalone binaries;
  5302 
  5303 * added ML_PLATFORM setting (useful for cross-platform installations);
  5304 more robust handling of platform specific ML images for SML/NJ;
  5305 
  5306 * the settings environment is now statically scoped, i.e. it is never
  5307 created again in sub-processes invoked from isabelle, isatool, or
  5308 Isabelle;
  5309 
  5310 * path element specification '~~' refers to '$ISABELLE_HOME';
  5311 
  5312 * in locales, the "assumes" and "defines" parts may be omitted if
  5313 empty;
  5314 
  5315 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5316 long arrows);
  5317 
  5318 * new print_mode "HTML";
  5319 
  5320 * new flag show_tags controls display of tags of theorems (which are
  5321 basically just comments that may be attached by some tools);
  5322 
  5323 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5324 mode and goal output format:
  5325 
  5326 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5327 244c244
  5328 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5329 ---
  5330 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5331 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5332 181c181
  5333 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5334 ---
  5335 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5336 
  5337 * function bind_thms stores lists of theorems (cf. bind_thm);
  5338 
  5339 * new shorthand tactics ftac, eatac, datac, fatac;
  5340 
  5341 * qed (and friends) now accept "" as result name; in that case the
  5342 theorem is not stored, but proper checks and presentation of the
  5343 result still apply;
  5344 
  5345 * theorem database now also indexes constants "Trueprop", "all",
  5346 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5347 
  5348 
  5349 *** HOL ***
  5350 
  5351 ** HOL arithmetic **
  5352 
  5353 * There are now decision procedures for linear arithmetic over nat and
  5354 int:
  5355 
  5356 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5357 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5358 are treated as atomic; subformulae not involving type `nat' or `int'
  5359 are ignored; quantified subformulae are ignored unless they are
  5360 positive universal or negative existential. The tactic has to be
  5361 invoked by hand and can be a little bit slow. In particular, the
  5362 running time is exponential in the number of occurrences of `min' and
  5363 `max', and `-' on `nat'.
  5364 
  5365 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5366 (negated) (in)equalities among the premises and the conclusion into
  5367 account (i.e. no compound formulae) and does not know about `min' and
  5368 `max', and `-' on `nat'. It is fast and is used automatically by the
  5369 simplifier.
  5370 
  5371 NB: At the moment, these decision procedures do not cope with mixed
  5372 nat/int formulae where the two parts interact, such as `m < n ==>
  5373 int(m) < int(n)'.
  5374 
  5375 * HOL/Numeral provides a generic theory of numerals (encoded
  5376 efficiently as bit strings); setup for types nat/int/real is in place;
  5377 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5378 int, existing theories and proof scripts may require a few additional
  5379 type constraints;
  5380 
  5381 * integer division and remainder can now be performed on constant
  5382 arguments;
  5383 
  5384 * many properties of integer multiplication, division and remainder
  5385 are now available;
  5386 
  5387 * An interface to the Stanford Validity Checker (SVC) is available through the
  5388 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5389 are proved automatically.  SVC must be installed separately, and its results
  5390 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5391 invocation of the underlying oracle).  For SVC see
  5392   http://verify.stanford.edu/SVC
  5393 
  5394 * IsaMakefile: the HOL-Real target now builds an actual image;
  5395 
  5396 
  5397 ** HOL misc **
  5398 
  5399 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5400 (in Isabelle/Isar) -- by Gertrud Bauer;
  5401 
  5402 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5403 analysis for assembly languages with subtypes;
  5404 
  5405 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5406 -- avoids syntactic ambiguities and treats state, transition, and
  5407 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5408 changed syntax and (many) tactics;
  5409 
  5410 * HOL/inductive: Now also handles more general introduction rules such
  5411   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5412   theorems are now maintained within the theory (maintained via the
  5413   "mono" attribute);
  5414 
  5415 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5416   (using function types) such as
  5417 
  5418   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5419 
  5420 * HOL/record: record_simproc (part of the default simpset) takes care
  5421 of selectors applied to updated records; record_split_tac is no longer
  5422 part of the default claset; update_defs may now be removed from the
  5423 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5424 
  5425   claset_ref () := claset() addSWrapper record_split_wrapper;
  5426   Delsimprocs [record_simproc]
  5427 
  5428 * HOL/typedef: fixed type inference for representing set; type
  5429 arguments now have to occur explicitly on the rhs as type constraints;
  5430 
  5431 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5432 names rather than an ML expression;
  5433 
  5434 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5435 supplied later.  Program schemes can be defined, such as
  5436     "While B C s = (if B s then While B C (C s) else s)"
  5437 where the well-founded relation can be chosen after B and C have been given.
  5438 
  5439 * HOL/List: the constructors of type list are now Nil and Cons;
  5440 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5441 course, ML tools referring to List.list.op # etc. have to be adapted;
  5442 
  5443 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5444 disabled by default; run isabelle with option -m HOL to get back to
  5445 the original Gordon/HOL-style output;
  5446 
  5447 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5448 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5449 
  5450 * HOL basic syntax simplified (more orthogonal): all variants of
  5451 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5452 Eps operator is provided as well: "SOME x. P[x]";
  5453 
  5454 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5455 
  5456 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5457 thus available for user theories;
  5458 
  5459 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5460 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5461 time;
  5462 
  5463 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5464 several times and then mp;
  5465 
  5466 
  5467 *** LK ***
  5468 
  5469 * the notation <<...>> is now available as a notation for sequences of
  5470 formulas;
  5471 
  5472 * the simplifier is now installed
  5473 
  5474 * the axiom system has been generalized (thanks to Soren Heilmann)
  5475 
  5476 * the classical reasoner now has a default rule database
  5477 
  5478 
  5479 *** ZF ***
  5480 
  5481 * new primrec section allows primitive recursive functions to be given
  5482 directly (as in HOL) over datatypes and the natural numbers;
  5483 
  5484 * new tactics induct_tac and exhaust_tac for induction (or case
  5485 analysis) over datatypes and the natural numbers;
  5486 
  5487 * the datatype declaration of type T now defines the recursor T_rec;
  5488 
  5489 * simplification automatically does freeness reasoning for datatype
  5490 constructors;
  5491 
  5492 * automatic type-inference, with AddTCs command to insert new
  5493 type-checking rules;
  5494 
  5495 * datatype introduction rules are now added as Safe Introduction rules
  5496 to the claset;
  5497 
  5498 * the syntax "if P then x else y" is now available in addition to
  5499 if(P,x,y);
  5500 
  5501 
  5502 *** Internal programming interfaces ***
  5503 
  5504 * tuned simplifier trace output; new flag debug_simp;
  5505 
  5506 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5507 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5508 
  5509 * AxClass.axclass_tac lost the theory argument;
  5510 
  5511 * tuned current_goals_markers semantics: begin / end goal avoids
  5512 printing empty lines;
  5513 
  5514 * removed prs and prs_fn hook, which was broken because it did not
  5515 include \n in its semantics, forcing writeln to add one
  5516 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5517 string -> unit if you really want to output text without newline;
  5518 
  5519 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5520 plain output, interface builders may have to enable 'isabelle_font'
  5521 mode to get Isabelle font glyphs as before;
  5522 
  5523 * refined token_translation interface; INCOMPATIBILITY: output length
  5524 now of type real instead of int;
  5525 
  5526 * theory loader actions may be traced via new ThyInfo.add_hook
  5527 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5528 your own database of information attached to *whole* theories -- as
  5529 opposed to intra-theory data slots offered via TheoryDataFun;
  5530 
  5531 * proper handling of dangling sort hypotheses (at last!);
  5532 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5533 extra sort hypotheses that can be witnessed from the type signature;
  5534 the force_strip_shyps flag is gone, any remaining shyps are simply
  5535 left in the theorem (with a warning issued by strip_shyps_warning);
  5536 
  5537 
  5538 
  5539 New in Isabelle98-1 (October 1998)
  5540 ----------------------------------
  5541 
  5542 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5543 
  5544 * several changes of automated proof tools;
  5545 
  5546 * HOL: major changes to the inductive and datatype packages, including
  5547 some minor incompatibilities of theory syntax;
  5548 
  5549 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5550 called `inj_on';
  5551 
  5552 * HOL: removed duplicate thms in Arith:
  5553   less_imp_add_less  should be replaced by  trans_less_add1
  5554   le_imp_add_le      should be replaced by  trans_le_add1
  5555 
  5556 * HOL: unary minus is now overloaded (new type constraints may be
  5557 required);
  5558 
  5559 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5560 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5561 now taken as an integer constant.
  5562 
  5563 * Pure: ML function 'theory_of' renamed to 'theory';
  5564 
  5565 
  5566 *** Proof tools ***
  5567 
  5568 * Simplifier:
  5569   1. Asm_full_simp_tac is now more aggressive.
  5570      1. It will sometimes reorient premises if that increases their power to
  5571         simplify.
  5572      2. It does no longer proceed strictly from left to right but may also
  5573         rotate premises to achieve further simplification.
  5574      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5575      old Asm_full_simp_tac in that it does not rotate premises.
  5576   2. The simplifier now knows a little bit about nat-arithmetic.
  5577 
  5578 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5579 allows for selected deletion of wrappers, by introduction of names for
  5580 wrapper functionals.  This implies that addbefore, addSbefore,
  5581 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5582 and that adding two tactics with the same name overwrites the first
  5583 one (emitting a warning).
  5584   type wrapper = (int -> tactic) -> (int -> tactic)
  5585   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5586   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5587   delWrapper, delSWrapper: claset *  string            -> claset
  5588   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5589 
  5590 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5591 semantics; addbefore now affects only the unsafe part of step_tac
  5592 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5593 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5594 by Force_tac;
  5595 
  5596 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5597 compWrapper; added safe wrapper (and access functions for it);
  5598 
  5599 * HOL/split_all_tac is now much faster and fails if there is nothing
  5600 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5601 and the names of the automatically generated variables have changed.
  5602 split_all_tac has moved within claset() from unsafe wrappers to safe
  5603 wrappers, which means that !!-bound variables are split much more
  5604 aggressively, and safe_tac and clarify_tac now split such variables.
  5605 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5606 Note: the same holds for record_split_tac, which does the job of
  5607 split_all_tac for record fields.
  5608 
  5609 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5610 permanently to the default simpset using Addsplits just like
  5611 Addsimps. They can be removed via Delsplits just like
  5612 Delsimps. Lower-case versions are also available.
  5613 
  5614 * HOL/Simplifier: The rule split_if is now part of the default
  5615 simpset. This means that the simplifier will eliminate all occurrences
  5616 of if-then-else in the conclusion of a goal. To prevent this, you can
  5617 either remove split_if completely from the default simpset by
  5618 `Delsplits [split_if]' or remove it in a specific call of the
  5619 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5620 other case splitting rules to/from the default simpset: every datatype
  5621 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5622 t is the name of the datatype).
  5623 
  5624 * Classical reasoner / Simplifier combination: new force_tac (and
  5625 derivatives Force_tac, force) combines rewriting and classical
  5626 reasoning (and whatever other tools) similarly to auto_tac, but is
  5627 aimed to solve the given subgoal completely.
  5628 
  5629 
  5630 *** General ***
  5631 
  5632 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5633 and `goalw': the theory is no longer needed as an explicit argument -
  5634 the current theory context is used; assumptions are no longer returned
  5635 at the ML-level unless one of them starts with ==> or !!; it is
  5636 recommended to convert to these new commands using isatool fixgoal
  5637 (backup your sources first!);
  5638 
  5639 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5640 the current theory context, and 'theory' to lookup stored theories;
  5641 
  5642 * new theory section 'locale' for declaring constants, assumptions and
  5643 definitions that have local scope;
  5644 
  5645 * new theory section 'nonterminals' for purely syntactic types;
  5646 
  5647 * new theory section 'setup' for generic ML setup functions
  5648 (e.g. package initialization);
  5649 
  5650 * the distribution now includes Isabelle icons: see
  5651 lib/logo/isabelle-{small,tiny}.xpm;
  5652 
  5653 * isatool install - install binaries with absolute references to
  5654 ISABELLE_HOME/bin;
  5655 
  5656 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5657 
  5658 * print mode 'emacs' reserved for Isamode;
  5659 
  5660 * support multiple print (ast) translations per constant name;
  5661 
  5662 * theorems involving oracles are now printed with a suffixed [!];
  5663 
  5664 
  5665 *** HOL ***
  5666 
  5667 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5668 
  5669 * HOL/inductive package reorganized and improved: now supports mutual
  5670 definitions such as
  5671 
  5672   inductive EVEN ODD
  5673     intrs
  5674       null "0 : EVEN"
  5675       oddI "n : EVEN ==> Suc n : ODD"
  5676       evenI "n : ODD ==> Suc n : EVEN"
  5677 
  5678 new theorem list "elims" contains an elimination rule for each of the
  5679 recursive sets; inductive definitions now handle disjunctive premises
  5680 correctly (also ZF);
  5681 
  5682 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5683 "mutual_induct" no longer exists - the induction rule is always
  5684 contained in "induct";
  5685 
  5686 
  5687 * HOL/datatype package re-implemented and greatly improved: now
  5688 supports mutually recursive datatypes such as
  5689 
  5690   datatype
  5691     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5692             | SUM ('a aexp) ('a aexp)
  5693             | DIFF ('a aexp) ('a aexp)
  5694             | NUM 'a
  5695   and
  5696     'a bexp = LESS ('a aexp) ('a aexp)
  5697             | AND ('a bexp) ('a bexp)
  5698             | OR ('a bexp) ('a bexp)
  5699 
  5700 as well as indirectly recursive datatypes such as
  5701 
  5702   datatype
  5703     ('a, 'b) term = Var 'a
  5704                   | App 'b ((('a, 'b) term) list)
  5705 
  5706 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5707 induction on mutually / indirectly recursive datatypes.
  5708 
  5709 Primrec equations are now stored in theory and can be accessed via
  5710 <function_name>.simps.
  5711 
  5712 INCOMPATIBILITIES:
  5713 
  5714   - Theories using datatypes must now have theory Datatype as an
  5715     ancestor.
  5716   - The specific <typename>.induct_tac no longer exists - use the
  5717     generic induct_tac instead.
  5718   - natE has been renamed to nat.exhaust - use exhaust_tac
  5719     instead of res_inst_tac ... natE. Note that the variable
  5720     names in nat.exhaust differ from the names in natE, this
  5721     may cause some "fragile" proofs to fail.
  5722   - The theorems split_<typename>_case and split_<typename>_case_asm
  5723     have been renamed to <typename>.split and <typename>.split_asm.
  5724   - Since default sorts of type variables are now handled correctly,
  5725     some datatype definitions may have to be annotated with explicit
  5726     sort constraints.
  5727   - Primrec definitions no longer require function name and type
  5728     of recursive argument.
  5729 
  5730 Consider using isatool fixdatatype to adapt your theories and proof
  5731 scripts to the new package (backup your sources first!).
  5732 
  5733 
  5734 * HOL/record package: considerably improved implementation; now
  5735 includes concrete syntax for record types, terms, updates; theorems
  5736 for surjective pairing and splitting !!-bound record variables; proof
  5737 support is as follows:
  5738 
  5739   1) standard conversions (selectors or updates applied to record
  5740 constructor terms) are part of the standard simpset;
  5741 
  5742   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5743 made part of standard simpset and claset via addIffs;
  5744 
  5745   3) a tactic for record field splitting (record_split_tac) is part of
  5746 the standard claset (addSWrapper);
  5747 
  5748 To get a better idea about these rules you may retrieve them via
  5749 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5750 the name of your record type.
  5751 
  5752 The split tactic 3) conceptually simplifies by the following rule:
  5753 
  5754   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5755 
  5756 Thus any record variable that is bound by meta-all will automatically
  5757 blow up into some record constructor term, consequently the
  5758 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5759 solve record problems automatically.
  5760 
  5761 
  5762 * reorganized the main HOL image: HOL/Integ and String loaded by
  5763 default; theory Main includes everything;
  5764 
  5765 * automatic simplification of integer sums and comparisons, using cancellation;
  5766 
  5767 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5768 
  5769 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5770 
  5771 * many new identities for unions, intersections, set difference, etc.;
  5772 
  5773 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5774 called split_if, split_split, split_sum_case and split_nat_case (to go
  5775 with add/delsplits);
  5776 
  5777 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5778 (?x::unit) = (); this is made part of the default simpset, which COULD
  5779 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5780 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5781 unit_abs_eta_conv is added in order to counter the effect of
  5782 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5783 %u.f();
  5784 
  5785 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5786 makes more sense);
  5787 
  5788 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5789   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5790   disjointness reasoning but breaking a few old proofs.
  5791 
  5792 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5793 to 'converse' from 'inverse' (for compatibility with ZF and some
  5794 literature);
  5795 
  5796 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5797 the well-founded relation;
  5798 
  5799 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5800     Compl A.  The "Compl" syntax remains available as input syntax for this
  5801     release ONLY.
  5802 
  5803 * HOL/Update: new theory of function updates:
  5804     f(a:=b) == %x. if x=a then b else f x
  5805 may also be iterated as in f(a:=b,c:=d,...);
  5806 
  5807 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5808 
  5809 * HOL/List:
  5810   - new function list_update written xs[i:=v] that updates the i-th
  5811     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5812   - new function `upt' written [i..j(] which generates the list
  5813     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5814     bound write [i..j], which is a shorthand for [i..j+1(].
  5815   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5816 
  5817 * HOL/Arith:
  5818   - removed 'pred' (predecessor) function;
  5819   - generalized some theorems about n-1;
  5820   - many new laws about "div" and "mod";
  5821   - new laws about greatest common divisors (see theory ex/Primes);
  5822 
  5823 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5824 instead of "inverse";
  5825 
  5826 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5827   of the multiset ordering;
  5828 
  5829 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5830   (not included by default);
  5831 
  5832 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5833 
  5834 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5835   programs, i.e. different program variables may have different types.
  5836 
  5837 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5838   [previously, this check worked only if the rewrite rule was unconditional]
  5839   Now rew can involve either definitions or equalities (either == or =).
  5840 
  5841 
  5842 *** ZF ***
  5843 
  5844 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5845   only the theorems proved on ZF.ML;
  5846 
  5847 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5848   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5849   disjointness reasoning but breaking a few old proofs.
  5850 
  5851 * ZF/Update: new theory of function updates
  5852     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5853   may also be iterated as in f(a:=b,c:=d,...);
  5854 
  5855 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5856 
  5857 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5858   [previously, this check worked only if the rewrite rule was unconditional]
  5859   Now rew can involve either definitions or equalities (either == or =).
  5860 
  5861 * case_tac provided for compatibility with HOL
  5862     (like the old excluded_middle_tac, but with subgoals swapped)
  5863 
  5864 
  5865 *** Internal programming interfaces ***
  5866 
  5867 * Pure: several new basic modules made available for general use, see
  5868 also src/Pure/README;
  5869 
  5870 * improved the theory data mechanism to support encapsulation (data
  5871 kind name replaced by private Object.kind, acting as authorization
  5872 key); new type-safe user interface via functor TheoryDataFun; generic
  5873 print_data function becomes basically useless;
  5874 
  5875 * removed global_names compatibility flag -- all theory declarations
  5876 are qualified by default;
  5877 
  5878 * module Pure/Syntax now offers quote / antiquote translation
  5879 functions (useful for Hoare logic etc. with implicit dependencies);
  5880 see HOL/ex/Antiquote for an example use;
  5881 
  5882 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5883 cterm -> thm;
  5884 
  5885 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5886 subgoal;
  5887 
  5888 * Display.print_goals function moved to Locale.print_goals;
  5889 
  5890 * standard print function for goals supports current_goals_markers
  5891 variable for marking begin of proof, end of proof, start of goal; the
  5892 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5893 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5894 for example;
  5895 
  5896 
  5897 
  5898 New in Isabelle98 (January 1998)
  5899 --------------------------------
  5900 
  5901 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5902 
  5903 * changed lexical syntax of terms / types: dots made part of long
  5904 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5905 
  5906 * simpset (and claset) reference variable replaced by functions
  5907 simpset / simpset_ref;
  5908 
  5909 * no longer supports theory aliases (via merge) and non-trivial
  5910 implicit merge of thms' signatures;
  5911 
  5912 * most internal names of constants changed due to qualified names;
  5913 
  5914 * changed Pure/Sequence interface (see Pure/seq.ML);
  5915 
  5916 
  5917 *** General Changes ***
  5918 
  5919 * hierachically structured name spaces (for consts, types, axms, thms
  5920 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5921 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5922 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5923 long_names for fully qualified output names; NOTE: ML programs
  5924 (special tactics, packages etc.) referring to internal names may have
  5925 to be adapted to cope with fully qualified names; in case of severe
  5926 backward campatibility problems try setting 'global_names' at compile
  5927 time to have enrything declared within a flat name space; one may also
  5928 fine tune name declarations in theories via the 'global' and 'local'
  5929 section;
  5930 
  5931 * reimplemented the implicit simpset and claset using the new anytype
  5932 data filed in signatures; references simpset:simpset ref etc. are
  5933 replaced by functions simpset:unit->simpset and
  5934 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5935 to patch your ML files accordingly;
  5936 
  5937 * HTML output now includes theory graph data for display with Java
  5938 applet or isatool browser; data generated automatically via isatool
  5939 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5940 
  5941 * defs may now be conditional; improved rewrite_goals_tac to handle
  5942 conditional equations;
  5943 
  5944 * defs now admits additional type arguments, using TYPE('a) syntax;
  5945 
  5946 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5947 creates a new theory node; implicit merge of thms' signatures is
  5948 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5949 transfer:theory->thm->thm in (rare) cases;
  5950 
  5951 * improved handling of draft signatures / theories; draft thms (and
  5952 ctyps, cterms) are automatically promoted to real ones;
  5953 
  5954 * slightly changed interfaces for oracles: admit many per theory, named
  5955 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5956 
  5957 * print_goals: optional output of const types (set show_consts and
  5958 show_types);
  5959 
  5960 * improved output of warnings (###) and errors (***);
  5961 
  5962 * subgoal_tac displays a warning if the new subgoal has type variables;
  5963 
  5964 * removed old README and Makefiles;
  5965 
  5966 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5967 
  5968 * removed obsolete init_pps and init_database;
  5969 
  5970 * deleted the obsolete tactical STATE, which was declared by
  5971     fun STATE tacfun st = tacfun st st;
  5972 
  5973 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5974 (which abbreviates $HOME);
  5975 
  5976 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5977 use isatool fixseq to adapt your ML programs (this works for fully
  5978 qualified references to the Sequence structure only!);
  5979 
  5980 * use_thy no longer requires writable current directory; it always
  5981 reloads .ML *and* .thy file, if either one is out of date;
  5982 
  5983 
  5984 *** Classical Reasoner ***
  5985 
  5986 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5987 tactics that use classical reasoning to simplify a subgoal without
  5988 splitting it into several subgoals;
  5989 
  5990 * Safe_tac: like safe_tac but uses the default claset;
  5991 
  5992 
  5993 *** Simplifier ***
  5994 
  5995 * added simplification meta rules:
  5996     (asm_)(full_)simplify: simpset -> thm -> thm;
  5997 
  5998 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5999 logics (again);
  6000 
  6001 * added prems argument to simplification procedures;
  6002 
  6003 * HOL, FOL, ZF: added infix function `addsplits':
  6004   instead of `<simpset> setloop (split_tac <thms>)'
  6005   you can simply write `<simpset> addsplits <thms>'
  6006 
  6007 
  6008 *** Syntax ***
  6009 
  6010 * TYPE('a) syntax for type reflection terms;
  6011 
  6012 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6013 
  6014 * pretty printer: changed order of mixfix annotation preference (again!);
  6015 
  6016 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6017 
  6018 
  6019 *** HOL ***
  6020 
  6021 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6022   with `addloop' of the simplifier to faciliate case splitting in premises.
  6023 
  6024 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6025 
  6026 * HOL/Auth: new protocol proofs including some for the Internet
  6027   protocol TLS;
  6028 
  6029 * HOL/Map: new theory of `maps' a la VDM;
  6030 
  6031 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6032 cancelling out common nat summands from =, <, <= (in)equalities, or
  6033 differences; simplification procedures nat_cancel_factor for
  6034 cancelling common factor from =, <, <= (in)equalities over natural
  6035 sums; nat_cancel contains both kinds of procedures, it is installed by
  6036 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6037 
  6038 * HOL/simplifier: terms of the form
  6039   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6040   are rewritten to
  6041   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6042   and those of the form
  6043   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6044   are rewritten to
  6045   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6046 
  6047 * HOL/datatype
  6048   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6049 
  6050   P(t_case f1 ... fn x) =
  6051      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6052         ...
  6053        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6054      )
  6055 
  6056   and a theorem `split_t_case_asm' of the form
  6057 
  6058   P(t_case f1 ... fn x) =
  6059     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6060         ...
  6061        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6062      )
  6063   which can be added to a simpset via `addsplits'. The existing theorems
  6064   expand_list_case and expand_option_case have been renamed to
  6065   split_list_case and split_option_case.
  6066 
  6067 * HOL/Arithmetic:
  6068   - `pred n' is automatically converted to `n-1'.
  6069     Users are strongly encouraged not to use `pred' any longer,
  6070     because it will disappear altogether at some point.
  6071   - Users are strongly encouraged to write "0 < n" rather than
  6072     "n ~= 0". Theorems and proof tools have been modified towards this
  6073     `standard'.
  6074 
  6075 * HOL/Lists:
  6076   the function "set_of_list" has been renamed "set" (and its theorems too);
  6077   the function "nth" now takes its arguments in the reverse order and
  6078   has acquired the infix notation "!" as in "xs!n".
  6079 
  6080 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6081 
  6082 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6083   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6084 
  6085 * HOL/record: extensible records with schematic structural subtyping
  6086 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6087 still lacks various theorems and concrete record syntax;
  6088 
  6089 
  6090 *** HOLCF ***
  6091 
  6092 * removed "axioms" and "generated by" sections;
  6093 
  6094 * replaced "ops" section by extended "consts" section, which is capable of
  6095   handling the continuous function space "->" directly;
  6096 
  6097 * domain package:
  6098   . proves theorems immediately and stores them in the theory,
  6099   . creates hierachical name space,
  6100   . now uses normal mixfix annotations (instead of cinfix...),
  6101   . minor changes to some names and values (for consistency),
  6102   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6103   . separator between mutual domain defs: changed "," to "and",
  6104   . improved handling of sort constraints;  now they have to
  6105     appear on the left-hand side of the equations only;
  6106 
  6107 * fixed LAM <x,y,zs>.b syntax;
  6108 
  6109 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6110 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6111 
  6112 
  6113 *** FOL and ZF ***
  6114 
  6115 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6116   with `addloop' of the simplifier to faciliate case splitting in premises.
  6117 
  6118 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6119 in HOL, they strip ALL and --> from proved theorems;
  6120 
  6121 
  6122 
  6123 New in Isabelle94-8 (May 1997)
  6124 ------------------------------
  6125 
  6126 *** General Changes ***
  6127 
  6128 * new utilities to build / run / maintain Isabelle etc. (in parts
  6129 still somewhat experimental); old Makefiles etc. still functional;
  6130 
  6131 * new 'Isabelle System Manual';
  6132 
  6133 * INSTALL text, together with ./configure and ./build scripts;
  6134 
  6135 * reimplemented type inference for greater efficiency, better error
  6136 messages and clean internal interface;
  6137 
  6138 * prlim command for dealing with lots of subgoals (an easier way of
  6139 setting goals_limit);
  6140 
  6141 
  6142 *** Syntax ***
  6143 
  6144 * supports alternative (named) syntax tables (parser and pretty
  6145 printer); internal interface is provided by add_modesyntax(_i);
  6146 
  6147 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6148 be used in conjunction with the Isabelle symbol font; uses the
  6149 "symbols" syntax table;
  6150 
  6151 * added token_translation interface (may translate name tokens in
  6152 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6153 the current print_mode); IMPORTANT: user print translation functions
  6154 are responsible for marking newly introduced bounds
  6155 (Syntax.mark_boundT);
  6156 
  6157 * token translations for modes "xterm" and "xterm_color" that display
  6158 names in bold, underline etc. or colors (which requires a color
  6159 version of xterm);
  6160 
  6161 * infixes may now be declared with names independent of their syntax;
  6162 
  6163 * added typed_print_translation (like print_translation, but may
  6164 access type of constant);
  6165 
  6166 
  6167 *** Classical Reasoner ***
  6168 
  6169 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6170 some limitations.  Blast_tac...
  6171   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6172   + ignores elimination rules that don't have the correct format
  6173         (the conclusion MUST be a formula variable)
  6174   + ignores types, which can make HOL proofs fail
  6175   + rules must not require higher-order unification, e.g. apply_type in ZF
  6176     [message "Function Var's argument not a bound variable" relates to this]
  6177   + its proof strategy is more general but can actually be slower
  6178 
  6179 * substitution with equality assumptions no longer permutes other
  6180 assumptions;
  6181 
  6182 * minor changes in semantics of addafter (now called addaltern); renamed
  6183 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6184 (and access functions for it);
  6185 
  6186 * improved combination of classical reasoner and simplifier:
  6187   + functions for handling clasimpsets
  6188   + improvement of addss: now the simplifier is called _after_ the
  6189     safe steps.
  6190   + safe variant of addss called addSss: uses safe simplifications
  6191     _during_ the safe steps. It is more complete as it allows multiple
  6192     instantiations of unknowns (e.g. with slow_tac).
  6193 
  6194 *** Simplifier ***
  6195 
  6196 * added interface for simplification procedures (functions that
  6197 produce *proven* rewrite rules on the fly, depending on current
  6198 redex);
  6199 
  6200 * ordering on terms as parameter (used for ordered rewriting);
  6201 
  6202 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6203 
  6204 * the solver is now split into a safe and an unsafe part.
  6205 This should be invisible for the normal user, except that the
  6206 functions setsolver and addsolver have been renamed to setSolver and
  6207 addSolver; added safe_asm_full_simp_tac;
  6208 
  6209 
  6210 *** HOL ***
  6211 
  6212 * a generic induction tactic `induct_tac' which works for all datatypes and
  6213 also for type `nat';
  6214 
  6215 * a generic case distinction tactic `exhaust_tac' which works for all
  6216 datatypes and also for type `nat';
  6217 
  6218 * each datatype comes with a function `size';
  6219 
  6220 * patterns in case expressions allow tuple patterns as arguments to
  6221 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6222 
  6223 * primrec now also works with type nat;
  6224 
  6225 * recdef: a new declaration form, allows general recursive functions to be
  6226 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6227 
  6228 * the constant for negation has been renamed from "not" to "Not" to
  6229 harmonize with FOL, ZF, LK, etc.;
  6230 
  6231 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6232 infinite lists;
  6233 
  6234 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6235 
  6236 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6237 problems in commutative rings, using axiomatic type classes for + and *;
  6238 
  6239 * more examples in HOL/MiniML and HOL/Auth;
  6240 
  6241 * more default rewrite rules for quantifiers, union/intersection;
  6242 
  6243 * a new constant `arbitrary == @x.False';
  6244 
  6245 * HOLCF/IOA replaces old HOL/IOA;
  6246 
  6247 * HOLCF changes: derived all rules and arities
  6248   + axiomatic type classes instead of classes
  6249   + typedef instead of faking type definitions
  6250   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6251   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6252   + eliminated the types void, one, tr
  6253   + use unit lift and bool lift (with translations) instead of one and tr
  6254   + eliminated blift from Lift3.thy (use Def instead of blift)
  6255   all eliminated rules are derived as theorems --> no visible changes ;
  6256 
  6257