NEWS
author nipkow
Wed Jul 22 10:49:26 2009 +0200 (2009-07-22)
changeset 32130 2a0645733185
parent 32079 5dc52b199815
child 32131 7913823f14e3
permissions -rw-r--r--
News
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * 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 
   127 *** System ***
   128 
   129 * Discontinued support for Poly/ML 4.x versions.
   130 
   131 * Removed "compress" option from isabelle-process and isabelle usedir;
   132 this is always enabled.
   133 
   134 * More fine-grained control of proof parallelism, cf.
   135 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   136 
   137 
   138 
   139 New in Isabelle2009 (April 2009)
   140 --------------------------------
   141 
   142 *** General ***
   143 
   144 * Simplified main Isabelle executables, with less surprises on
   145 case-insensitive file-systems (such as Mac OS).
   146 
   147   - The main Isabelle tool wrapper is now called "isabelle" instead of
   148     "isatool."
   149 
   150   - The former "isabelle" alias for "isabelle-process" has been
   151     removed (should rarely occur to regular users).
   152 
   153   - The former "isabelle-interface" and its alias "Isabelle" have been
   154     removed (interfaces are now regular Isabelle tools).
   155 
   156 Within scripts and make files, the Isabelle environment variables
   157 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   158 respectively.  (The latter are still available as legacy feature.)
   159 
   160 The old isabelle-interface wrapper could react in confusing ways if
   161 the interface was uninstalled or changed otherwise.  Individual
   162 interface tool configuration is now more explicit, see also the
   163 Isabelle system manual.  In particular, Proof General is now available
   164 via "isabelle emacs".
   165 
   166 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   167 purge installed copies of Isabelle executables and re-run "isabelle
   168 install -p ...", or use symlinks.
   169 
   170 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   171 old ~/isabelle, which was slightly non-standard and apt to cause
   172 surprises on case-insensitive file-systems (such as Mac OS).
   173 
   174 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   175 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   176 care is required when using older releases of Isabelle.  Note that
   177 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   178 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   179 
   180 * Proofs of fully specified statements are run in parallel on
   181 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   182 a regular 4-core machine, if the initial heap space is made reasonably
   183 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   184 
   185 * The main reference manuals ("isar-ref", "implementation", and
   186 "system") have been updated and extended.  Formally checked references
   187 as hyperlinks are now available uniformly.
   188 
   189 
   190 *** Pure ***
   191 
   192 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   193 respects.  The most important changes are listed below.  See the
   194 Tutorial on Locales ("locales" manual) for details.
   195 
   196 - In locale expressions, instantiation replaces renaming.  Parameters
   197 must be declared in a for clause.  To aid compatibility with previous
   198 parameter inheritance, in locale declarations, parameters that are not
   199 'touched' (instantiation position "_" or omitted) are implicitly added
   200 with their syntax at the beginning of the for clause.
   201 
   202 - Syntax from abbreviations and definitions in locales is available in
   203 locale expressions and context elements.  The latter is particularly
   204 useful in locale declarations.
   205 
   206 - More flexible mechanisms to qualify names generated by locale
   207 expressions.  Qualifiers (prefixes) may be specified in locale
   208 expressions, and can be marked as mandatory (syntax: "name!:") or
   209 optional (syntax "name?:").  The default depends for plain "name:"
   210 depends on the situation where a locale expression is used: in
   211 commands 'locale' and 'sublocale' prefixes are optional, in
   212 'interpretation' and 'interpret' prefixes are mandatory.  The old
   213 implicit qualifiers derived from the parameter names of a locale are
   214 no longer generated.
   215 
   216 - Command "sublocale l < e" replaces "interpretation l < e".  The
   217 instantiation clause in "interpretation" and "interpret" (square
   218 brackets) is no longer available.  Use locale expressions.
   219 
   220 - When converting proof scripts, mandatory qualifiers in
   221 'interpretation' and 'interpret' should be retained by default, even
   222 if this is an INCOMPATIBILITY compared to former behavior.  In the
   223 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   224 in locale expressions range over a single locale instance only.
   225 
   226 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   227 In existing theorem specifications replace the includes element by the
   228 respective context elements of the included locale, omitting those
   229 that are already present in the theorem specification.  Multiple
   230 assume elements of a locale should be replaced by a single one
   231 involving the locale predicate.  In the proof body, declarations (most
   232 notably theorems) may be regained by interpreting the respective
   233 locales in the proof context as required (command "interpret").
   234 
   235 If using "includes" in replacement of a target solely because the
   236 parameter types in the theorem are not as general as in the target,
   237 consider declaring a new locale with additional type constraints on
   238 the parameters (context element "constrains").
   239 
   240 - Discontinued "locale (open)".  INCOMPATIBILITY.
   241 
   242 - Locale interpretation commands no longer attempt to simplify goal.
   243 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   244 methods intro_locales and unfold_locales to clarify.
   245 
   246 - Locale interpretation commands no longer accept interpretation
   247 attributes.  INCOMPATIBILITY.
   248 
   249 * Class declaration: so-called "base sort" must not be given in import
   250 list any longer, but is inferred from the specification.  Particularly
   251 in HOL, write
   252 
   253     class foo = ...
   254 
   255 instead of
   256 
   257     class foo = type + ...
   258 
   259 * Class target: global versions of theorems stemming do not carry a
   260 parameter prefix any longer.  INCOMPATIBILITY.
   261 
   262 * Class 'instance' command no longer accepts attached definitions.
   263 INCOMPATIBILITY, use proper 'instantiation' target instead.
   264 
   265 * Recovered hiding of consts, which was accidentally broken in
   266 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   267 makes c inaccessible; consider using ``hide (open) const c'' instead.
   268 
   269 * Slightly more coherent Pure syntax, with updated documentation in
   270 isar-ref manual.  Removed locales meta_term_syntax and
   271 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   272 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   273 directly in regular applications.
   274 
   275 * There is a new syntactic category "float_const" for signed decimal
   276 fractions (e.g. 123.45 or -123.45).
   277 
   278 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   279 interface with 'setup' command instead.
   280 
   281 * Command 'local_setup' is similar to 'setup', but operates on a local
   282 theory context.
   283 
   284 * The 'axiomatization' command now only works within a global theory
   285 context.  INCOMPATIBILITY.
   286 
   287 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   288 hypotheses.  Sorts required in the course of reasoning need to be
   289 covered by the constraints in the initial statement, completed by the
   290 type instance information of the background theory.  Non-trivial sort
   291 hypotheses, which rarely occur in practice, may be specified via
   292 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   293 
   294   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   295 
   296 The result contains an implicit sort hypotheses as before --
   297 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   298 normalization.
   299 
   300 * Generalized Isar history, with support for linear undo, direct state
   301 addressing etc.
   302 
   303 * Changed defaults for unify configuration options:
   304 
   305   unify_trace_bound = 50 (formerly 25)
   306   unify_search_bound = 60 (formerly 30)
   307 
   308 * Different bookkeeping for code equations (INCOMPATIBILITY):
   309 
   310   a) On theory merge, the last set of code equations for a particular
   311      constant is taken (in accordance with the policy applied by other
   312      parts of the code generator framework).
   313 
   314   b) Code equations stemming from explicit declarations (e.g. code
   315      attribute) gain priority over default code equations stemming
   316      from definition, primrec, fun etc.
   317 
   318 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   319 
   320 * Unified theorem tables for both code generators.  Thus [code
   321 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   322 
   323 * Command 'find_consts' searches for constants based on type and name
   324 patterns, e.g.
   325 
   326     find_consts "_ => bool"
   327 
   328 By default, matching is against subtypes, but it may be restricted to
   329 the whole type.  Searching by name is possible.  Multiple queries are
   330 conjunctive and queries may be negated by prefixing them with a
   331 hyphen:
   332 
   333     find_consts strict: "_ => bool" name: "Int" -"int => int"
   334 
   335 * New 'find_theorems' criterion "solves" matches theorems that
   336 directly solve the current goal (modulo higher-order unification).
   337 
   338 * Auto solve feature for main theorem statements: whenever a new goal
   339 is stated, "find_theorems solves" is called; any theorems that could
   340 solve the lemma directly are listed as part of the goal state.
   341 Cf. associated options in Proof General Isabelle settings menu,
   342 enabled by default, with reasonable timeout for pathological cases of
   343 higher-order unification.
   344 
   345 
   346 *** Document preparation ***
   347 
   348 * Antiquotation @{lemma} now imitates a regular terminal proof,
   349 demanding keyword 'by' and supporting the full method expression
   350 syntax just like the Isar command 'by'.
   351 
   352 
   353 *** HOL ***
   354 
   355 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   356 points Main and Complex_Main remain as before.
   357 
   358 * Logic image HOL-Plain provides a minimal HOL with the most important
   359 tools available (inductive, datatype, primrec, ...).  This facilitates
   360 experimentation and tool development.  Note that user applications
   361 (and library theories) should never refer to anything below theory
   362 Main, as before.
   363 
   364 * Logic image HOL-Main stops at theory Main, and thus facilitates
   365 experimentation due to shorter build times.
   366 
   367 * Logic image HOL-NSA contains theories of nonstandard analysis which
   368 were previously part of former HOL-Complex.  Entry point Hyperreal
   369 remains valid, but theories formerly using Complex_Main should now use
   370 new entry point Hypercomplex.
   371 
   372 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   373 Posix processes.  Avoids potentially expensive forking of the ML
   374 process.  New thread-based implementation also works on non-Unix
   375 platforms (Cygwin).  Provers are no longer hardwired, but defined
   376 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   377 commands are covered in the isar-ref manual.
   378 
   379 * Wrapper scripts for remote SystemOnTPTP service allows to use
   380 sledgehammer without local ATP installation (Vampire etc.). Other
   381 provers may be included via suitable ML wrappers, see also
   382 src/HOL/ATP_Linkup.thy.
   383 
   384 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   385 menu.
   386 
   387 * The metis method no longer fails because the theorem is too trivial
   388 (contains the empty clause).
   389 
   390 * The metis method now fails in the usual manner, rather than raising
   391 an exception, if it determines that it cannot prove the theorem.
   392 
   393 * Method "coherent" implements a prover for coherent logic (see also
   394 src/Tools/coherent.ML).
   395 
   396 * Constants "undefined" and "default" replace "arbitrary".  Usually
   397 "undefined" is the right choice to replace "arbitrary", though
   398 logically there is no difference.  INCOMPATIBILITY.
   399 
   400 * Command "value" now integrates different evaluation mechanisms.  The
   401 result of the first successful evaluation mechanism is printed.  In
   402 square brackets a particular named evaluation mechanisms may be
   403 specified (currently, [SML], [code] or [nbe]).  See further
   404 src/HOL/ex/Eval_Examples.thy.
   405 
   406 * Normalization by evaluation now allows non-leftlinear equations.
   407 Declare with attribute [code nbe].
   408 
   409 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   410 as the structured Isar versions "cases" and "induct", cf. the
   411 corresponding "cases" and "induct" attributes.  Mutual induction rules
   412 are now presented as a list of individual projections
   413 (e.g. foo_bar.inducts for types foo and bar); the old format with
   414 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   415 rare situations a different rule is selected --- notably nested tuple
   416 elimination instead of former prod.exhaust: use explicit (case_tac t
   417 rule: prod.exhaust) here.
   418 
   419 * Attributes "cases", "induct", "coinduct" support "del" option.
   420 
   421 * Removed fact "case_split_thm", which duplicates "case_split".
   422 
   423 * The option datatype has been moved to a new theory Option.  Renamed
   424 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   425 
   426 * New predicate "strict_mono" classifies strict functions on partial
   427 orders.  With strict functions on linear orders, reasoning about
   428 (in)equalities is facilitated by theorems "strict_mono_eq",
   429 "strict_mono_less_eq" and "strict_mono_less".
   430 
   431 * Some set operations are now proper qualified constants with
   432 authentic syntax.  INCOMPATIBILITY:
   433 
   434     op Int ~>   Set.Int
   435     op Un ~>    Set.Un
   436     INTER ~>    Set.INTER
   437     UNION ~>    Set.UNION
   438     Inter ~>    Set.Inter
   439     Union ~>    Set.Union
   440     {} ~>       Set.empty
   441     UNIV ~>     Set.UNIV
   442 
   443 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   444 theory Set.
   445 
   446 * Auxiliary class "itself" has disappeared -- classes without any
   447 parameter are treated as expected by the 'class' command.
   448 
   449 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   450 
   451 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   452 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   453 
   454 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   455 method "approximation".  It proves formulas on real values by using
   456 interval arithmetic.  In the formulas are also the transcendental
   457 functions sin, cos, tan, atan, ln, exp and the constant pi are
   458 allowed. For examples see
   459 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   460 
   461 * Theory "Reflection" now resides in HOL/Library.
   462 
   463 * Entry point to Word library now simply named "Word".
   464 INCOMPATIBILITY.
   465 
   466 * Made source layout more coherent with logical distribution
   467 structure:
   468 
   469     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   470     src/HOL/Library/Code_Message.thy ~> src/HOL/
   471     src/HOL/Library/GCD.thy ~> src/HOL/
   472     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   473     src/HOL/Library/Parity.thy ~> src/HOL/
   474     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   475     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   476     src/HOL/Real/Lubs.thy ~> src/HOL/
   477     src/HOL/Real/PReal.thy ~> src/HOL/
   478     src/HOL/Real/Rational.thy ~> src/HOL/
   479     src/HOL/Real/RComplete.thy ~> src/HOL/
   480     src/HOL/Real/RealDef.thy ~> src/HOL/
   481     src/HOL/Real/RealPow.thy ~> src/HOL/
   482     src/HOL/Real/Real.thy ~> src/HOL/
   483     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   484     src/HOL/Complex/Complex.thy ~> src/HOL/
   485     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   486     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   487     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   488     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   489     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   490     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   491     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   492     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   493     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   494     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   495     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   496     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   497     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   498     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   499     src/HOL/Real/Float ~> src/HOL/Library/
   500     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   501     src/HOL/Real/RealVector.thy ~> src/HOL/
   502 
   503     src/HOL/arith_data.ML ~> src/HOL/Tools
   504     src/HOL/hologic.ML ~> src/HOL/Tools
   505     src/HOL/simpdata.ML ~> src/HOL/Tools
   506     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   507     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   508     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   509     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   510     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   511     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   512     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   513 
   514     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   515     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   516     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   517     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   518     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   519     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   520 
   521 * If methods "eval" and "evaluation" encounter a structured proof
   522 state with !!/==>, only the conclusion is evaluated to True (if
   523 possible), avoiding strange error messages.
   524 
   525 * Method "sizechange" automates termination proofs using (a
   526 modification of) the size-change principle.  Requires SAT solver.  See
   527 src/HOL/ex/Termination.thy for examples.
   528 
   529 * Simplifier: simproc for let expressions now unfolds if bound
   530 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   531 
   532 * Method "arith": Linear arithmetic now ignores all inequalities when
   533 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   534 
   535 * New attribute "arith" for facts that should always be used
   536 automatically by arithmetic. It is intended to be used locally in
   537 proofs, e.g.
   538 
   539   assumes [arith]: "x > 0"
   540 
   541 Global usage is discouraged because of possible performance impact.
   542 
   543 * New classes "top" and "bot" with corresponding operations "top" and
   544 "bot" in theory Orderings; instantiation of class "complete_lattice"
   545 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   546 
   547 * Changed definition lemma "less_fun_def" in order to provide an
   548 instance for preorders on functions; use lemma "less_le" instead.
   549 INCOMPATIBILITY.
   550 
   551 * Theory Orderings: class "wellorder" moved here, with explicit
   552 induction rule "less_induct" as assumption.  For instantiation of
   553 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   554 INCOMPATIBILITY.
   555 
   556 * Theory Orderings: added class "preorder" as superclass of "order".
   557 INCOMPATIBILITY: Instantiation proofs for order, linorder
   558 etc. slightly changed.  Some theorems named order_class.* now named
   559 preorder_class.*.
   560 
   561 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   562 "diag" to "Id_on".
   563 
   564 * Theory Finite_Set: added a new fold combinator of type
   565 
   566   ('a => 'b => 'b) => 'b => 'a set => 'b
   567 
   568 Occasionally this is more convenient than the old fold combinator
   569 which is now defined in terms of the new one and renamed to
   570 fold_image.
   571 
   572 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   573 and "ring_simps" have been replaced by "algebra_simps" (which can be
   574 extended with further lemmas!).  At the moment both still exist but
   575 the former will disappear at some point.
   576 
   577 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   578 class recpower.  Type-specific simp rules for various recpower types
   579 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   580 
   581 rat_power_0    -> power_0
   582 rat_power_Suc  -> power_Suc
   583 realpow_0      -> power_0
   584 realpow_Suc    -> power_Suc
   585 complexpow_0   -> power_0
   586 complexpow_Suc -> power_Suc
   587 power_poly_0   -> power_0
   588 power_poly_Suc -> power_Suc
   589 
   590 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   591 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   592 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   593 of lemmas from Divides has been generalized from nat to class
   594 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   595 renames resulting from duplicate elimination:
   596 
   597     dvd_def_mod ~>          dvd_eq_mod_eq_0
   598     zero_dvd_iff ~>         dvd_0_left_iff
   599     dvd_0 ~>                dvd_0_right
   600     DIVISION_BY_ZERO_DIV ~> div_by_0
   601     DIVISION_BY_ZERO_MOD ~> mod_by_0
   602     mult_div ~>             div_mult_self2_is_id
   603     mult_mod ~>             mod_mult_self2_is_0
   604 
   605 * Theory IntDiv: removed many lemmas that are instances of class-based
   606 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   607 rename old lemmas as follows:
   608 
   609 dvd_diff               -> nat_dvd_diff
   610 dvd_zminus_iff         -> dvd_minus_iff
   611 mod_add1_eq            -> mod_add_eq
   612 mod_mult1_eq           -> mod_mult_right_eq
   613 mod_mult1_eq'          -> mod_mult_left_eq
   614 mod_mult_distrib_mod   -> mod_mult_eq
   615 nat_mod_add_left_eq    -> mod_add_left_eq
   616 nat_mod_add_right_eq   -> mod_add_right_eq
   617 nat_mod_div_trivial    -> mod_div_trivial
   618 nat_mod_mod_trivial    -> mod_mod_trivial
   619 zdiv_zadd_self1        -> div_add_self1
   620 zdiv_zadd_self2        -> div_add_self2
   621 zdiv_zmult_self1       -> div_mult_self2_is_id
   622 zdiv_zmult_self2       -> div_mult_self1_is_id
   623 zdvd_triv_left         -> dvd_triv_left
   624 zdvd_triv_right        -> dvd_triv_right
   625 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   626 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   627 zmod_zadd_left_eq      -> mod_add_left_eq
   628 zmod_zadd_right_eq     -> mod_add_right_eq
   629 zmod_zadd_self1        -> mod_add_self1
   630 zmod_zadd_self2        -> mod_add_self2
   631 zmod_zadd1_eq          -> mod_add_eq
   632 zmod_zdiff1_eq         -> mod_diff_eq
   633 zmod_zdvd_zmod         -> mod_mod_cancel
   634 zmod_zmod_cancel       -> mod_mod_cancel
   635 zmod_zmult_self1       -> mod_mult_self2_is_0
   636 zmod_zmult_self2       -> mod_mult_self1_is_0
   637 zmod_1                 -> mod_by_1
   638 zdiv_1                 -> div_by_1
   639 zdvd_abs1              -> abs_dvd_iff
   640 zdvd_abs2              -> dvd_abs_iff
   641 zdvd_refl              -> dvd_refl
   642 zdvd_trans             -> dvd_trans
   643 zdvd_zadd              -> dvd_add
   644 zdvd_zdiff             -> dvd_diff
   645 zdvd_zminus_iff        -> dvd_minus_iff
   646 zdvd_zminus2_iff       -> minus_dvd_iff
   647 zdvd_zmultD            -> dvd_mult_right
   648 zdvd_zmultD2           -> dvd_mult_left
   649 zdvd_zmult_mono        -> mult_dvd_mono
   650 zdvd_0_right           -> dvd_0_right
   651 zdvd_0_left            -> dvd_0_left_iff
   652 zdvd_1_left            -> one_dvd
   653 zminus_dvd_iff         -> minus_dvd_iff
   654 
   655 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   656 
   657 * The real numbers offer decimal input syntax: 12.34 is translated
   658 into 1234/10^2. This translation is not reversed upon output.
   659 
   660 * Theory Library/Polynomial defines an abstract type 'a poly of
   661 univariate polynomials with coefficients of type 'a.  In addition to
   662 the standard ring operations, it also supports div and mod.  Code
   663 generation is also supported, using list-style constructors.
   664 
   665 * Theory Library/Inner_Product defines a class of real_inner for real
   666 inner product spaces, with an overloaded operation inner :: 'a => 'a
   667 => real.  Class real_inner is a subclass of real_normed_vector from
   668 theory RealVector.
   669 
   670 * Theory Library/Product_Vector provides instances for the product
   671 type 'a * 'b of several classes from RealVector and Inner_Product.
   672 Definitions of addition, subtraction, scalar multiplication, norms,
   673 and inner products are included.
   674 
   675 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   676 addition to the field operations, numerals and case syntax are also
   677 supported.
   678 
   679 * Theory Library/Diagonalize provides constructive version of Cantor's
   680 first diagonalization argument.
   681 
   682 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   683 zlcm (for int); carried together from various gcd/lcm developements in
   684 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   685 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   686 may recover tupled syntax as follows:
   687 
   688     hide (open) const gcd
   689     abbreviation gcd where
   690       "gcd == (%(a, b). GCD.gcd a b)"
   691     notation (output)
   692       GCD.gcd ("gcd '(_, _')")
   693 
   694 The same works for lcm, zgcd, zlcm.
   695 
   696 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   697 instantiations for algebraic structures.  Removed some duplicate
   698 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   699 
   700 * ML antiquotation @{code} takes a constant as argument and generates
   701 corresponding code in background and inserts name of the corresponding
   702 resulting ML value/function/datatype constructor binding in place.
   703 All occurrences of @{code} with a single ML block are generated
   704 simultaneously.  Provides a generic and safe interface for
   705 instrumentalizing code generation.  See
   706 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   707 In future you ought to refrain from ad-hoc compiling generated SML
   708 code on the ML toplevel.  Note that (for technical reasons) @{code}
   709 cannot refer to constants for which user-defined serializations are
   710 set.  Refer to the corresponding ML counterpart directly in that
   711 cases.
   712 
   713 * Command 'rep_datatype': instead of theorem names the command now
   714 takes a list of terms denoting the constructors of the type to be
   715 represented as datatype.  The characteristic theorems have to be
   716 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   717 have disappeared in favour of existing ones:
   718 
   719     unit_induct                 ~> unit.induct
   720     prod_induct                 ~> prod.induct
   721     sum_induct                  ~> sum.induct
   722     Suc_Suc_eq                  ~> nat.inject
   723     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   724 
   725 
   726 *** HOL-Algebra ***
   727 
   728 * New locales for orders and lattices where the equivalence relation
   729 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   730 locales use a record structure with field eq for the equivalence.
   731 
   732 * New theory of factorial domains.
   733 
   734 * Units_l_inv and Units_r_inv are now simp rules by default.
   735 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   736 and/or r_inv will now also require deletion of these lemmas.
   737 
   738 * Renamed the following theorems, INCOMPATIBILITY:
   739 
   740 UpperD ~> Upper_memD
   741 LowerD ~> Lower_memD
   742 least_carrier ~> least_closed
   743 greatest_carrier ~> greatest_closed
   744 greatest_Lower_above ~> greatest_Lower_below
   745 one_zero ~> carrier_one_zero
   746 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   747 
   748 
   749 *** HOL-Nominal ***
   750 
   751 * Nominal datatypes can now contain type-variables.
   752 
   753 * Commands 'nominal_inductive' and 'equivariance' work with local
   754 theory targets.
   755 
   756 * Nominal primrec can now works with local theory targets and its
   757 specification syntax now conforms to the general format as seen in
   758 'inductive' etc.
   759 
   760 * Method "perm_simp" honours the standard simplifier attributes
   761 (no_asm), (no_asm_use) etc.
   762 
   763 * The new predicate #* is defined like freshness, except that on the
   764 left hand side can be a set or list of atoms.
   765 
   766 * Experimental command 'nominal_inductive2' derives strong induction
   767 principles for inductive definitions.  In contrast to
   768 'nominal_inductive', which can only deal with a fixed number of
   769 binders, it can deal with arbitrary expressions standing for sets of
   770 atoms to be avoided.  The only inductive definition we have at the
   771 moment that needs this generalisation is the typing rule for Lets in
   772 the algorithm W:
   773 
   774  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   775  -----------------------------------------------------------------
   776          Gamma |- Let x be t1 in t2 : T2
   777 
   778 In this rule one wants to avoid all the binders that are introduced by
   779 "close Gamma T1".  We are looking for other examples where this
   780 feature might be useful.  Please let us know.
   781 
   782 
   783 *** HOLCF ***
   784 
   785 * Reimplemented the simplification procedure for proving continuity
   786 subgoals.  The new simproc is extensible; users can declare additional
   787 continuity introduction rules with the attribute [cont2cont].
   788 
   789 * The continuity simproc now uses a different introduction rule for
   790 solving continuity subgoals on terms with lambda abstractions.  In
   791 some rare cases the new simproc may fail to solve subgoals that the
   792 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   793 Potential INCOMPATIBILITY.
   794 
   795 * Command 'fixrec': specification syntax now conforms to the general
   796 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   797 examples.  INCOMPATIBILITY.
   798 
   799 
   800 *** ZF ***
   801 
   802 * Proof of Zorn's Lemma for partial orders.
   803 
   804 
   805 *** ML ***
   806 
   807 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   808 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   809 depends on multithreading, so timouts will not work before Poly/ML
   810 5.2.1!
   811 
   812 * High-level support for concurrent ML programming, see
   813 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   814 particularly convenient to organize independent functional
   815 computations.  The concept of "synchronized variables" provides a
   816 higher-order interface for components with shared state, avoiding the
   817 delicate details of mutexes and condition variables.  (Requires
   818 Poly/ML 5.2.1 or later.)
   819 
   820 * ML bindings produced via Isar commands are stored within the Isar
   821 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   822 become thread-safe and work with undo as expected (concerning
   823 top-level bindings, not side-effects on global references).
   824 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   825 compiler at runtime; really global bindings need to be given outside a
   826 theory.  (Requires Poly/ML 5.2 or later.)
   827 
   828 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   829 context.  Top-level ML bindings are stored within the proof context in
   830 a purely sequential fashion, disregarding the nested proof structure.
   831 ML bindings introduced by 'ML_prf' are discarded at the end of the
   832 proof.  (Requires Poly/ML 5.2 or later.)
   833 
   834 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   835 and Method.setup, as well as Isar commands 'attribute_setup' and
   836 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   837 existing code accordingly, or use plain 'setup' together with old
   838 Method.add_method.
   839 
   840 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   841 to 'a -> thm, while results are always tagged with an authentic oracle
   842 name.  The Isar command 'oracle' is now polymorphic, no argument type
   843 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   844 accordingly.  Note that extra performance may be gained by producing
   845 the cterm carefully, avoiding slow Thm.cterm_of.
   846 
   847 * Simplified interface for defining document antiquotations via
   848 ThyOutput.antiquotation, ThyOutput.output, and optionally
   849 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   850 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   851 examples.
   852 
   853 * More systematic treatment of long names, abstract name bindings, and
   854 name space operations.  Basic operations on qualified names have been
   855 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   856 Long_Name.append.  Old type bstring has been mostly replaced by
   857 abstract type binding (see structure Binding), which supports precise
   858 qualification by packages and local theory targets, as well as proper
   859 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   860 bstring values into Binding.name, or better pass through abstract
   861 bindings everywhere.  See further src/Pure/General/long_name.ML,
   862 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   863 
   864 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   865 LocalTheory.note etc.) now refer to the *full* internal name, not the
   866 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   867 
   868 * Disposed old type and term read functions (Sign.read_def_typ,
   869 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   870 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   871 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   872 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   873 resort for legacy applications.
   874 
   875 * Disposed old declarations, tactics, tactic combinators that refer to
   876 the simpset or claset of an implicit theory (such as Addsimps,
   877 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   878 embedded ML text, or local_simpset_of with a proper context passed as
   879 explicit runtime argument.
   880 
   881 * Rules and tactics that read instantiations (read_instantiate,
   882 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   883 context, which is required for parsing and type-checking.  Moreover,
   884 the variables are specified as plain indexnames, not string encodings
   885 thereof.  INCOMPATIBILITY.
   886 
   887 * Generic Toplevel.add_hook interface allows to analyze the result of
   888 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   889 for theorem dependency output of transactions resulting in a new
   890 theory state.
   891 
   892 * ML antiquotations: block-structured compilation context indicated by
   893 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   894 
   895   @{binding name}                         - basic name binding
   896   @{let ?pat = term}                      - term abbreviation (HO matching)
   897   @{note name = fact}                     - fact abbreviation
   898   @{thm fact}                             - singleton fact (with attributes)
   899   @{thms fact}                            - general fact (with attributes)
   900   @{lemma prop by method}                 - singleton goal
   901   @{lemma prop by meth1 meth2}            - singleton goal
   902   @{lemma prop1 ... propN by method}      - general goal
   903   @{lemma prop1 ... propN by meth1 meth2} - general goal
   904   @{lemma (open) ...}                     - open derivation
   905 
   906 
   907 *** System ***
   908 
   909 * The Isabelle "emacs" tool provides a specific interface to invoke
   910 Proof General / Emacs, with more explicit failure if that is not
   911 installed (the old isabelle-interface script silently falls back on
   912 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   913 installation location of the Proof General distribution.
   914 
   915 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   916 the Isabelle process into a JVM/Scala application.  See
   917 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   918 process wrapper has been discontinued.)
   919 
   920 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   921 
   922 * Various status messages (with exact source position information) are
   923 emitted, if proper markup print mode is enabled.  This allows
   924 user-interface components to provide detailed feedback on internal
   925 prover operations.
   926 
   927 
   928 
   929 New in Isabelle2008 (June 2008)
   930 -------------------------------
   931 
   932 *** General ***
   933 
   934 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   935 and updated, with formally checked references as hyperlinks.
   936 
   937 * Theory loader: use_thy (and similar operations) no longer set the
   938 implicit ML context, which was occasionally hard to predict and in
   939 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   940 provides a proper context already.
   941 
   942 * Theory loader: old-style ML proof scripts being *attached* to a thy
   943 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   944 'use' within a theory file will do the job.
   945 
   946 * Name space merge now observes canonical order, i.e. the second space
   947 is inserted into the first one, while existing entries in the first
   948 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   949 swap theory imports.
   950 
   951 * Syntax: symbol \<chi> is now considered a letter.  Potential
   952 INCOMPATIBILITY in identifier syntax etc.
   953 
   954 * Outer syntax: string tokens no longer admit escaped white space,
   955 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   956 white space without escapes.
   957 
   958 * Outer syntax: string tokens may contain arbitrary character codes
   959 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   960 "foo_bar".
   961 
   962 
   963 *** Pure ***
   964 
   965 * Context-dependent token translations.  Default setup reverts locally
   966 fixed variables, and adds hilite markup for undeclared frees.
   967 
   968 * Unused theorems can be found using the new command 'unused_thms'.
   969 There are three ways of invoking it:
   970 
   971 (1) unused_thms
   972      Only finds unused theorems in the current theory.
   973 
   974 (2) unused_thms thy_1 ... thy_n -
   975      Finds unused theorems in the current theory and all of its ancestors,
   976      excluding the theories thy_1 ... thy_n and all of their ancestors.
   977 
   978 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   979      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   980      their ancestors, excluding the theories thy_1 ... thy_n and all of
   981      their ancestors.
   982 
   983 In order to increase the readability of the list produced by
   984 unused_thms, theorems that have been created by a particular instance
   985 of a theory command such as 'inductive' or 'function' are considered
   986 to belong to the same "group", meaning that if at least one theorem in
   987 this group is used, the other theorems in the same group are no longer
   988 reported as unused.  Moreover, if all theorems in the group are
   989 unused, only one theorem in the group is displayed.
   990 
   991 Note that proof objects have to be switched on in order for
   992 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   993 usually the case when using Proof General with the default settings).
   994 
   995 * Authentic naming of facts disallows ad-hoc overwriting of previous
   996 theorems within the same name space.  INCOMPATIBILITY, need to remove
   997 duplicate fact bindings, or even accidental fact duplications.  Note
   998 that tools may maintain dynamically scoped facts systematically, using
   999 PureThy.add_thms_dynamic.
  1000 
  1001 * Command 'hide' now allows to hide from "fact" name space as well.
  1002 
  1003 * Eliminated destructive theorem database, simpset, claset, and
  1004 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1005 update of theories within ML code.
  1006 
  1007 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1008 INCOMPATIBILITY, object-logics depending on former Pure require
  1009 additional setup PureThy.old_appl_syntax_setup; object-logics
  1010 depending on former CPure need to refer to Pure.
  1011 
  1012 * Commands 'use' and 'ML' are now purely functional, operating on
  1013 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1014 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1015 INCOMPATIBILITY.
  1016 
  1017 * Command 'setup': discontinued implicit version with ML reference.
  1018 
  1019 * Instantiation target allows for simultaneous specification of class
  1020 instance operations together with an instantiation proof.
  1021 Type-checking phase allows to refer to class operations uniformly.
  1022 See src/HOL/Complex/Complex.thy for an Isar example and
  1023 src/HOL/Library/Eval.thy for an ML example.
  1024 
  1025 * Indexing of literal facts: be more serious about including only
  1026 facts from the visible specification/proof context, but not the
  1027 background context (locale etc.).  Affects `prop` notation and method
  1028 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1029 situations.
  1030 
  1031 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1032 "(open)" option, which used to expose internal bound variables to the
  1033 proof text.
  1034 
  1035 * Isar statements: removed obsolete case "rule_context".
  1036 INCOMPATIBILITY, better use explicit fixes/assumes.
  1037 
  1038 * Locale proofs: default proof step now includes 'unfold_locales';
  1039 hence 'proof' without argument may be used to unfold locale
  1040 predicates.
  1041 
  1042 
  1043 *** Document preparation ***
  1044 
  1045 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1046 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1047 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1048 spot); renamed link color from "darkblue" to "linkcolor" (default
  1049 value unchanged, can be redefined via \definecolor); no longer sets
  1050 "a4paper" option (unnecessary or even intrusive).
  1051 
  1052 * Antiquotation @{lemma A method} proves proposition A by the given
  1053 method (either a method name or a method name plus (optional) method
  1054 arguments in parentheses) and prints A just like @{prop A}.
  1055 
  1056 
  1057 *** HOL ***
  1058 
  1059 * New primrec package.  Specification syntax conforms in style to
  1060 definition/function/....  No separate induction rule is provided.  The
  1061 "primrec" command distinguishes old-style and new-style specifications
  1062 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1063 When adjusting theories, beware: constants stemming from new-style
  1064 primrec specifications have authentic syntax.
  1065 
  1066 * Metis prover is now an order of magnitude faster, and also works
  1067 with multithreading.
  1068 
  1069 * Metis: the maximum number of clauses that can be produced from a
  1070 theorem is now given by the attribute max_clauses.  Theorems that
  1071 exceed this number are ignored, with a warning printed.
  1072 
  1073 * Sledgehammer no longer produces structured proofs by default. To
  1074 enable, declare [[sledgehammer_full = true]].  Attributes
  1075 reconstruction_modulus, reconstruction_sorts renamed
  1076 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1077 
  1078 * Method "induct_scheme" derives user-specified induction rules
  1079 from well-founded induction and completeness of patterns. This factors
  1080 out some operations that are done internally by the function package
  1081 and makes them available separately.  See
  1082 src/HOL/ex/Induction_Scheme.thy for examples.
  1083 
  1084 * More flexible generation of measure functions for termination
  1085 proofs: Measure functions can be declared by proving a rule of the
  1086 form "is_measure f" and giving it the [measure_function] attribute.
  1087 The "is_measure" predicate is logically meaningless (always true), and
  1088 just guides the heuristic.  To find suitable measure functions, the
  1089 termination prover sets up the goal "is_measure ?f" of the appropriate
  1090 type and generates all solutions by prolog-style backwards proof using
  1091 the declared rules.
  1092 
  1093 This setup also deals with rules like 
  1094 
  1095   "is_measure f ==> is_measure (list_size f)"
  1096 
  1097 which accommodates nested datatypes that recurse through lists.
  1098 Similar rules are predeclared for products and option types.
  1099 
  1100 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1101 
  1102   INCOMPATIBILITIES:
  1103 
  1104   - Definitions of overloaded constants on sets have to be replaced by
  1105     definitions on => and bool.
  1106 
  1107   - Some definitions of overloaded operators on sets can now be proved
  1108     using the definitions of the operators on => and bool.  Therefore,
  1109     the following theorems have been renamed:
  1110 
  1111       subset_def   -> subset_eq
  1112       psubset_def  -> psubset_eq
  1113       set_diff_def -> set_diff_eq
  1114       Compl_def    -> Compl_eq
  1115       Sup_set_def  -> Sup_set_eq
  1116       Inf_set_def  -> Inf_set_eq
  1117       sup_set_def  -> sup_set_eq
  1118       inf_set_def  -> inf_set_eq
  1119 
  1120   - Due to the incompleteness of the HO unification algorithm, some
  1121     rules such as subst may require manual instantiation, if some of
  1122     the unknowns in the rule is a set.
  1123 
  1124   - Higher order unification and forward proofs:
  1125     The proof pattern
  1126 
  1127       have "P (S::'a set)" <...>
  1128       then have "EX S. P S" ..
  1129 
  1130     no longer works (due to the incompleteness of the HO unification
  1131     algorithm) and must be replaced by the pattern
  1132 
  1133       have "EX S. P S"
  1134       proof
  1135         show "P S" <...>
  1136       qed
  1137 
  1138   - Calculational reasoning with subst (or similar rules):
  1139     The proof pattern
  1140 
  1141       have "P (S::'a set)" <...>
  1142       also have "S = T" <...>
  1143       finally have "P T" .
  1144 
  1145     no longer works (for similar reasons as the previous example) and
  1146     must be replaced by something like
  1147 
  1148       have "P (S::'a set)" <...>
  1149       moreover have "S = T" <...>
  1150       ultimately have "P T" by simp
  1151 
  1152   - Tactics or packages written in ML code:
  1153     Code performing pattern matching on types via
  1154 
  1155       Type ("set", [T]) => ...
  1156 
  1157     must be rewritten. Moreover, functions like strip_type or
  1158     binder_types no longer return the right value when applied to a
  1159     type of the form
  1160 
  1161       T1 => ... => Tn => U => bool
  1162 
  1163     rather than
  1164 
  1165       T1 => ... => Tn => U set
  1166 
  1167 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1168 Wellfounded_Relations to theory Wellfounded.
  1169 
  1170 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1171 
  1172 * Class finite no longer treats UNIV as class parameter.  Use class
  1173 enum from theory Library/Enum instead to achieve a similar effect.
  1174 INCOMPATIBILITY.
  1175 
  1176 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1177 and "Cons".  INCOMPATIBILITY.
  1178 
  1179 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1180 Potential INCOMPATIBILITY.
  1181 
  1182 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1183 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1184 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1185 
  1186 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1187 the same name in theory Orderings:
  1188 
  1189   less_trans
  1190   less_linear
  1191   le_imp_less_or_eq
  1192   le_less_trans
  1193   less_le_trans
  1194   less_not_sym
  1195   less_asym
  1196 
  1197 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1198 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1199 and different variable names.
  1200 
  1201 * Library/Option_ord.thy: Canonical order on option type.
  1202 
  1203 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1204 finite maps.
  1205 
  1206 * Library/Countable.thy: Type class for countable types.
  1207 
  1208 * Theory Int: The representation of numerals has changed.  The infix
  1209 operator BIT and the bit datatype with constructors B0 and B1 have
  1210 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1211 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1212 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1213 accordingly.
  1214 
  1215 * Theory Nat: definition of <= and < on natural numbers no longer
  1216 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1217 le_def and less_def have disappeared.  Consider lemmas not_less
  1218 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1219 
  1220 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1221 (whose purpose mainly is for various fold_set functionals) have been
  1222 abandoned in favor of the existing algebraic classes
  1223 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1224 lower_semilattice (resp. upper_semilattice) and linorder.
  1225 INCOMPATIBILITY.
  1226 
  1227 * Theory Transitive_Closure: induct and cases rules now declare proper
  1228 case_names ("base" and "step").  INCOMPATIBILITY.
  1229 
  1230 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1231 lattices.  The form set-specific version is available as
  1232 Inductive.lfp_ordinal_induct_set.
  1233 
  1234 * Renamed theorems "power.simps" to "power_int.simps".
  1235 INCOMPATIBILITY.
  1236 
  1237 * Class semiring_div provides basic abstract properties of semirings
  1238 with division and modulo operations.  Subsumes former class dvd_mod.
  1239 
  1240 * Merged theories IntDef, Numeral and IntArith into unified theory
  1241 Int.  INCOMPATIBILITY.
  1242 
  1243 * Theory Library/Code_Index: type "index" now represents natural
  1244 numbers rather than integers.  INCOMPATIBILITY.
  1245 
  1246 * New class "uminus" with operation "uminus" (split of from class
  1247 "minus" which now only has operation "minus", binary).
  1248 INCOMPATIBILITY.
  1249 
  1250 * Constants "card", "internal_split", "option_map" now with authentic
  1251 syntax.  INCOMPATIBILITY.
  1252 
  1253 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1254 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1255 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1256 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1257 Sup_set_def, le_def, less_def, option_map_def now with object
  1258 equality.  INCOMPATIBILITY.
  1259 
  1260 * Records. Removed K_record, and replaced it by pure lambda term
  1261 %x. c. The simplifier setup is now more robust against eta expansion.
  1262 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1263 
  1264 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1265 
  1266 * Library/ListVector: new theory of arithmetic vector operations.
  1267 
  1268 * Library/Order_Relation: new theory of various orderings as sets of
  1269 pairs.  Defines preorders, partial orders, linear orders and
  1270 well-orders on sets and on types.
  1271 
  1272 
  1273 *** ZF ***
  1274 
  1275 * Renamed some theories to allow to loading both ZF and HOL in the
  1276 same session:
  1277 
  1278   Datatype  -> Datatype_ZF
  1279   Inductive -> Inductive_ZF
  1280   Int       -> Int_ZF
  1281   IntDiv    -> IntDiv_ZF
  1282   Nat       -> Nat_ZF
  1283   List      -> List_ZF
  1284   Main      -> Main_ZF
  1285 
  1286 INCOMPATIBILITY: ZF theories that import individual theories below
  1287 Main might need to be adapted.  Regular theory Main is still
  1288 available, as trivial extension of Main_ZF.
  1289 
  1290 
  1291 *** ML ***
  1292 
  1293 * ML within Isar: antiquotation @{const name} or @{const
  1294 name(typargs)} produces statically-checked Const term.
  1295 
  1296 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1297 (of the same name).  Removed obsolete print command.
  1298 
  1299 * Removed obsolete "use_legacy_bindings" function.
  1300 
  1301 * The ``print mode'' is now a thread-local value derived from a global
  1302 template (the former print_mode reference), thus access becomes
  1303 non-critical.  The global print_mode reference is for session
  1304 management only; user-code should use print_mode_value,
  1305 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1306 
  1307 * Functions system/system_out provide a robust way to invoke external
  1308 shell commands, with propagation of interrupts (requires Poly/ML
  1309 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1310 
  1311 
  1312 *** System ***
  1313 
  1314 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1315 in accordance with Proof General 3.7, which prefers GNU emacs.
  1316 
  1317 * isatool tty runs Isabelle process with plain tty interaction;
  1318 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1319 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1320 
  1321 * isatool browser now works with Cygwin as well, using general
  1322 "javapath" function defined in Isabelle process environment.
  1323 
  1324 * YXML notation provides a simple and efficient alternative to
  1325 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1326 isatool yxml as described in the Isabelle system manual.
  1327 
  1328 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1329 provides general wrapper for managing an Isabelle process in a robust
  1330 fashion, with ``cooked'' output from stdin/stderr.
  1331 
  1332 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1333 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1334 
  1335 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1336 way of changing the user's settings is via
  1337 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1338 script.
  1339 
  1340 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1341 cores of the underlying machine, which is a good starting point for
  1342 optimal performance tuning.  The corresponding usedir option -M allows
  1343 "max" as an alias for "0".  WARNING: does not work on certain versions
  1344 of Mac OS (with Poly/ML 5.1).
  1345 
  1346 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1347 adverse effect of Isabelle flooding interactive front-ends (notably
  1348 ProofGeneral / XEmacs).
  1349 
  1350 
  1351 
  1352 New in Isabelle2007 (November 2007)
  1353 -----------------------------------
  1354 
  1355 *** General ***
  1356 
  1357 * More uniform information about legacy features, notably a
  1358 warning/error of "Legacy feature: ...", depending on the state of the
  1359 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1360 legacy features will disappear eventually.
  1361 
  1362 * Theory syntax: the header format ``theory A = B + C:'' has been
  1363 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1364 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1365 
  1366 * Theory syntax: the old non-Isar theory file format has been
  1367 discontinued altogether.  Note that ML proof scripts may still be used
  1368 with Isar theories; migration is usually quite simple with the ML
  1369 function use_legacy_bindings.  INCOMPATIBILITY.
  1370 
  1371 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1372 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1373 quotes.
  1374 
  1375 * Theory loader: be more serious about observing the static theory
  1376 header specifications (including optional directories), but not the
  1377 accidental file locations of previously successful loads.  The strict
  1378 update policy of former update_thy is now already performed by
  1379 use_thy, so the former has been removed; use_thys updates several
  1380 theories simultaneously, just as 'imports' within a theory header
  1381 specification, but without merging the results.  Potential
  1382 INCOMPATIBILITY: may need to refine theory headers and commands
  1383 ROOT.ML which depend on load order.
  1384 
  1385 * Theory loader: optional support for content-based file
  1386 identification, instead of the traditional scheme of full physical
  1387 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1388 (cf. the system manual).  The new scheme allows to work with
  1389 non-finished theories in persistent session images, such that source
  1390 files may be moved later on without requiring reloads.
  1391 
  1392 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1393 file (with the same base name as the theory) are considered a legacy
  1394 feature, which will disappear eventually. Even now, the theory loader
  1395 no longer maintains dependencies on such files.
  1396 
  1397 * Syntax: the scope for resolving ambiguities via type-inference is
  1398 now limited to individual terms, instead of whole simultaneous
  1399 specifications as before. This greatly reduces the complexity of the
  1400 syntax module and improves flexibility by separating parsing and
  1401 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1402 'fixes' etc.) are required in rare situations.
  1403 
  1404 * Syntax: constants introduced by new-style packages ('definition',
  1405 'abbreviation' etc.) are passed through the syntax module in
  1406 ``authentic mode''. This means that associated mixfix annotations
  1407 really stick to such constants, independently of potential name space
  1408 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1409 trees are represented slightly differently, may need to adapt syntax
  1410 translations accordingly. Use CONST marker in 'translations' and
  1411 @{const_syntax} antiquotation in 'parse_translation' etc.
  1412 
  1413 * Legacy goal package: reduced interface to the bare minimum required
  1414 to keep existing proof scripts running.  Most other user-level
  1415 functions are now part of the OldGoals structure, which is *not* open
  1416 by default (consider isatool expandshort before open OldGoals).
  1417 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1418 these tend to cause confusion about the actual goal (!) context being
  1419 used here, which is not necessarily the same as the_context().
  1420 
  1421 * Command 'find_theorems': supports "*" wild-card in "name:"
  1422 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1423 support a specific search form (see ProofGeneral/CHANGES).
  1424 
  1425 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1426 by default, which means that "prems" (and also "fixed variables") are
  1427 suppressed from proof state output.  Note that the ProofGeneral
  1428 settings mechanism allows to change and save options persistently, but
  1429 older versions of Isabelle will fail to start up if a negative prems
  1430 limit is imposed.
  1431 
  1432 * Local theory targets may be specified by non-nested blocks of
  1433 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1434 contain definitions, theorems etc., including any derived mechanism
  1435 that has been implemented on top of these primitives.  This concept
  1436 generalizes the existing ``theorem (in ...)'' towards more versatility
  1437 and scalability.
  1438 
  1439 * Proof General interface: proper undo of final 'end' command;
  1440 discontinued Isabelle/classic mode (ML proof scripts).
  1441 
  1442 
  1443 *** Document preparation ***
  1444 
  1445 * Added antiquotation @{theory name} which prints the given name,
  1446 after checking that it refers to a valid ancestor theory in the
  1447 current context.
  1448 
  1449 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1450 check the given source text as ML type/structure, printing verbatim.
  1451 
  1452 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1453 "c args == rhs" given in the current context.  (Any number of
  1454 arguments may be given on the LHS.)
  1455 
  1456 
  1457 *** Pure ***
  1458 
  1459 * The 'class' package offers a combination of axclass and locale to
  1460 achieve Haskell-like type classes in Isabelle.  Definitions and
  1461 theorems within a class context produce both relative results (with
  1462 implicit parameters according to the locale context), and polymorphic
  1463 constants with qualified polymorphism (according to the class
  1464 context).  Within the body context of a 'class' target, a separate
  1465 syntax layer ("user space type system") takes care of converting
  1466 between global polymorphic consts and internal locale representation.
  1467 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1468 "isatool doc classes" provides a tutorial.
  1469 
  1470 * Generic code generator framework allows to generate executable
  1471 code for ML and Haskell (including Isabelle classes).  A short usage
  1472 sketch:
  1473 
  1474     internal compilation:
  1475         export_code <list of constants (term syntax)> in SML
  1476     writing SML code to a file:
  1477         export_code <list of constants (term syntax)> in SML <filename>
  1478     writing OCaml code to a file:
  1479         export_code <list of constants (term syntax)> in OCaml <filename>
  1480     writing Haskell code to a bunch of files:
  1481         export_code <list of constants (term syntax)> in Haskell <filename>
  1482 
  1483     evaluating closed propositions to True/False using code generation:
  1484         method ``eval''
  1485 
  1486 Reasonable default setup of framework in HOL.
  1487 
  1488 Theorem attributs for selecting and transforming function equations theorems:
  1489 
  1490     [code fun]:        select a theorem as function equation for a specific constant
  1491     [code fun del]:    deselect a theorem as function equation for a specific constant
  1492     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1493     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1494 
  1495 User-defined serializations (target in {SML, OCaml, Haskell}):
  1496 
  1497     code_const <and-list of constants (term syntax)>
  1498       {(target) <and-list of const target syntax>}+
  1499 
  1500     code_type <and-list of type constructors>
  1501       {(target) <and-list of type target syntax>}+
  1502 
  1503     code_instance <and-list of instances>
  1504       {(target)}+
  1505         where instance ::= <type constructor> :: <class>
  1506 
  1507     code_class <and_list of classes>
  1508       {(target) <and-list of class target syntax>}+
  1509         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1510 
  1511 code_instance and code_class only are effective to target Haskell.
  1512 
  1513 For example usage see src/HOL/ex/Codegenerator.thy and
  1514 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1515 generation from Isabelle/HOL theories is available via "isatool doc
  1516 codegen".
  1517 
  1518 * Code generator: consts in 'consts_code' Isar commands are now
  1519 referred to by usual term syntax (including optional type
  1520 annotations).
  1521 
  1522 * Command 'no_translations' removes translation rules from theory
  1523 syntax.
  1524 
  1525 * Overloaded definitions are now actually checked for acyclic
  1526 dependencies.  The overloading scheme is slightly more general than
  1527 that of Haskell98, although Isabelle does not demand an exact
  1528 correspondence to type class and instance declarations.
  1529 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1530 exotic versions of overloading -- at the discretion of the user!
  1531 
  1532 Polymorphic constants are represented via type arguments, i.e. the
  1533 instantiation that matches an instance against the most general
  1534 declaration given in the signature.  For example, with the declaration
  1535 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1536 as c(nat).  Overloading is essentially simultaneous structural
  1537 recursion over such type arguments.  Incomplete specification patterns
  1538 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1539 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1540 Command 'print_theory' outputs the normalized system of recursive
  1541 equations, see section "definitions".
  1542 
  1543 * Configuration options are maintained within the theory or proof
  1544 context (with name and type bool/int/string), providing a very simple
  1545 interface to a poor-man's version of general context data.  Tools may
  1546 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1547 these values using Config.get etc.  Users may change options via an
  1548 associated attribute of the same name.  This form of context
  1549 declaration works particularly well with commands 'declare' or
  1550 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1551 very easy to avoid global references, which would not observe Isar
  1552 toplevel undo/redo and fail to work with multithreading.
  1553 
  1554 Various global ML references of Pure and HOL have been turned into
  1555 configuration options:
  1556 
  1557   Unify.search_bound		unify_search_bound
  1558   Unify.trace_bound		unify_trace_bound
  1559   Unify.trace_simp		unify_trace_simp
  1560   Unify.trace_types		unify_trace_types
  1561   Simplifier.simp_depth_limit	simp_depth_limit
  1562   Blast.depth_limit		blast_depth_limit
  1563   DatatypeProp.dtK		datatype_distinctness_limit
  1564   fast_arith_neq_limit  	fast_arith_neq_limit
  1565   fast_arith_split_limit	fast_arith_split_limit
  1566 
  1567 * Named collections of theorems may be easily installed as context
  1568 data using the functor NamedThmsFun (see also
  1569 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1570 attributes; there is also a toplevel print command.  This facility is
  1571 just a common case of general context data, which is the preferred way
  1572 for anything more complex than just a list of facts in canonical
  1573 order.
  1574 
  1575 * Isar: command 'declaration' augments a local theory by generic
  1576 declaration functions written in ML.  This enables arbitrary content
  1577 being added to the context, depending on a morphism that tells the
  1578 difference of the original declaration context wrt. the application
  1579 context encountered later on.
  1580 
  1581 * Isar: proper interfaces for simplification procedures.  Command
  1582 'simproc_setup' declares named simprocs (with match patterns, and body
  1583 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1584 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1585 
  1586 * Isar: an extra pair of brackets around attribute declarations
  1587 abbreviates a theorem reference involving an internal dummy fact,
  1588 which will be ignored later --- only the effect of the attribute on
  1589 the background context will persist.  This form of in-place
  1590 declarations is particularly useful with commands like 'declare' and
  1591 'using', for example ``have A using [[simproc a]] by simp''.
  1592 
  1593 * Isar: method "assumption" (and implicit closing of subproofs) now
  1594 takes simple non-atomic goal assumptions into account: after applying
  1595 an assumption as a rule the resulting subgoals are solved by atomic
  1596 assumption steps.  This is particularly useful to finish 'obtain'
  1597 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1598 without referring to the original premise "!!x. P x ==> thesis" in the
  1599 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1600 more permissive.
  1601 
  1602 * Isar: implicit use of prems from the Isar proof context is
  1603 considered a legacy feature.  Common applications like ``have A .''
  1604 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1605 referencing facts explicitly here improves readability and
  1606 maintainability of proof texts.
  1607 
  1608 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1609 the obtained context from the course of reasoning!  For example:
  1610 
  1611   assume "EX x y. A x & B y"   -- "any previous fact"
  1612   then guess x and y by clarify
  1613 
  1614 This technique is potentially adventurous, depending on the facts and
  1615 proof tools being involved here.
  1616 
  1617 * Isar: known facts from the proof context may be specified as literal
  1618 propositions, using ASCII back-quote syntax.  This works wherever
  1619 named facts used to be allowed so far, in proof commands, proof
  1620 methods, attributes etc.  Literal facts are retrieved from the context
  1621 according to unification of type and term parameters.  For example,
  1622 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1623 theorems in the current context, then these are valid literal facts:
  1624 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1625 
  1626 There is also a proof method "fact" which does the same composition
  1627 for explicit goal states, e.g. the following proof texts coincide with
  1628 certain special cases of literal facts:
  1629 
  1630   have "A" by fact                 ==  note `A`
  1631   have "A ==> B" by fact           ==  note `A ==> B`
  1632   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1633   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1634 
  1635 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1636 outer syntax.  Thus symbolic identifiers may be used without
  1637 additional white space in declarations like this: ``assume *: A''.
  1638 
  1639 * Isar: 'print_facts' prints all local facts of the current context,
  1640 both named and unnamed ones.
  1641 
  1642 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1643 
  1644   def x == "t" and y == "u"
  1645 
  1646 * Isar: added command 'unfolding', which is structurally similar to
  1647 'using', but affects both the goal state and facts by unfolding given
  1648 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1649 'unfolded' attribute may be replaced by first-class proof text.
  1650 
  1651 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1652 and command 'unfolding' now all support object-level equalities
  1653 (potentially conditional).  The underlying notion of rewrite rule is
  1654 analogous to the 'rule_format' attribute, but *not* that of the
  1655 Simplifier (which is usually more generous).
  1656 
  1657 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1658 premises of a theorem by n. Useful in conjunction with drule.
  1659 
  1660 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1661 method expression within a sandbox consisting of the first N
  1662 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1663 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1664 simplifies all new goals that emerge from applying rule foo to the
  1665 originally first one.
  1666 
  1667 * Isar: schematic goals are no longer restricted to higher-order
  1668 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1669 expected.
  1670 
  1671 * Isar: the conclusion of a long theorem statement is now either
  1672 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1673 (essentially a disjunction of cases with local parameters and
  1674 assumptions).  The latter allows to express general elimination rules
  1675 adequately; in this notation common elimination rules look like this:
  1676 
  1677   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1678     assumes "EX x. P x"
  1679     obtains x where "P x"
  1680 
  1681   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1682     assumes "A & B"
  1683     obtains A and B
  1684 
  1685   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1686     assumes "A | B"
  1687     obtains
  1688       A
  1689     | B
  1690 
  1691 The subsequent classical rules even refer to the formal "thesis"
  1692 explicitly:
  1693 
  1694   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1695     obtains "~ thesis"
  1696 
  1697   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1698     obtains "thesis ==> something"
  1699 
  1700 The actual proof of an 'obtains' statement is analogous to that of the
  1701 Isar proof element 'obtain', only that there may be several cases.
  1702 Optional case names may be specified in parentheses; these will be
  1703 available both in the present proof and as annotations in the
  1704 resulting rule, for later use with the 'cases' method (cf. attribute
  1705 case_names).
  1706 
  1707 * Isar: the assumptions of a long theorem statement are available as
  1708 "assms" fact in the proof context.  This is more appropriate than the
  1709 (historical) "prems", which refers to all assumptions of the current
  1710 context, including those from the target locale, proof body etc.
  1711 
  1712 * Isar: 'print_statement' prints theorems from the current theory or
  1713 proof context in long statement form, according to the syntax of a
  1714 top-level lemma.
  1715 
  1716 * Isar: 'obtain' takes an optional case name for the local context
  1717 introduction rule (default "that").
  1718 
  1719 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1720 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1721 to occur.
  1722 
  1723 * Pure: syntax "CONST name" produces a fully internalized constant
  1724 according to the current context.  This is particularly useful for
  1725 syntax translations that should refer to internal constant
  1726 representations independently of name spaces.
  1727 
  1728 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1729 instead of "FOO ". This allows multiple binder declarations to coexist
  1730 in the same context.  INCOMPATIBILITY.
  1731 
  1732 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1733 primitive that also works in a locale context (both for constants and
  1734 fixed variables). Type declaration and internal syntactic representation
  1735 of given constants retrieved from the context. Likewise, the
  1736 'no_notation' command allows to remove given syntax annotations from the
  1737 current context.
  1738 
  1739 * Isar/locales: new derived specification elements 'axiomatization',
  1740 'definition', 'abbreviation', which support type-inference, admit
  1741 object-level specifications (equality, equivalence).  See also the
  1742 isar-ref manual.  Examples:
  1743 
  1744   axiomatization
  1745     eq  (infix "===" 50) where
  1746     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1747 
  1748   definition "f x y = x + y + 1"
  1749   definition g where "g x = f x x"
  1750 
  1751   abbreviation
  1752     neq  (infix "=!=" 50) where
  1753     "x =!= y == ~ (x === y)"
  1754 
  1755 These specifications may be also used in a locale context.  Then the
  1756 constants being introduced depend on certain fixed parameters, and the
  1757 constant name is qualified by the locale base name.  An internal
  1758 abbreviation takes care for convenient input and output, making the
  1759 parameters implicit and using the original short name.  See also
  1760 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1761 entities from a monomorphic theory.
  1762 
  1763 Presently, abbreviations are only available 'in' a target locale, but
  1764 not inherited by general import expressions.  Also note that
  1765 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1766 'translations' in common applications.  The "no_abbrevs" print mode
  1767 prevents folding of abbreviations in term output.
  1768 
  1769 Concrete syntax is attached to specified constants in internal form,
  1770 independently of name spaces.  The parse tree representation is
  1771 slightly different -- use 'notation' instead of raw 'syntax', and
  1772 'translations' with explicit "CONST" markup to accommodate this.
  1773 
  1774 * Pure/Isar: unified syntax for new-style specification mechanisms
  1775 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1776 full type inference and dummy patterns ("_").  For example:
  1777 
  1778   definition "K x _ = x"
  1779 
  1780   inductive conj for A B
  1781   where "A ==> B ==> conj A B"
  1782 
  1783 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1784 the current context.  Print mode "no_abbrevs" prevents inversion of
  1785 abbreviations on output.
  1786 
  1787 * Isar/locales: improved parameter handling: use of locales "var" and
  1788 "struct" no longer necessary; - parameter renamings are no longer
  1789 required to be injective.  For example, this allows to define
  1790 endomorphisms as locale endom = homom mult mult h.
  1791 
  1792 * Isar/locales: changed the way locales with predicates are defined.
  1793 Instead of accumulating the specification, the imported expression is
  1794 now an interpretation.  INCOMPATIBILITY: different normal form of
  1795 locale expressions.  In particular, in interpretations of locales with
  1796 predicates, goals repesenting already interpreted fragments are not
  1797 removed automatically.  Use methods `intro_locales' and
  1798 `unfold_locales'; see below.
  1799 
  1800 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1801 provide backward reasoning on locales predicates.  The methods are
  1802 aware of interpretations and discharge corresponding goals.
  1803 `intro_locales' is less aggressive then `unfold_locales' and does not
  1804 unfold predicates to assumptions.
  1805 
  1806 * Isar/locales: the order in which locale fragments are accumulated
  1807 has changed.  This enables to override declarations from fragments due
  1808 to interpretations -- for example, unwanted simp rules.
  1809 
  1810 * Isar/locales: interpretation in theories and proof contexts has been
  1811 extended.  One may now specify (and prove) equations, which are
  1812 unfolded in interpreted theorems.  This is useful for replacing
  1813 defined concepts (constants depending on locale parameters) by
  1814 concepts already existing in the target context.  Example:
  1815 
  1816   interpretation partial_order ["op <= :: [int, int] => bool"]
  1817     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1818 
  1819 Typically, the constant `partial_order.less' is created by a
  1820 definition specification element in the context of locale
  1821 partial_order.
  1822 
  1823 * Method "induct": improved internal context management to support
  1824 local fixes and defines on-the-fly. Thus explicit meta-level
  1825 connectives !!  and ==> are rarely required anymore in inductive goals
  1826 (using object-logic connectives for this purpose has been long
  1827 obsolete anyway). Common proof patterns are explained in
  1828 src/HOL/Induct/Common_Patterns.thy, see also
  1829 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1830 examples.
  1831 
  1832 * Method "induct": improved handling of simultaneous goals. Instead of
  1833 introducing object-level conjunction, the statement is now split into
  1834 several conclusions, while the corresponding symbolic cases are nested
  1835 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1836 see src/HOL/Induct/Common_Patterns.thy, for example.
  1837 
  1838 * Method "induct": mutual induction rules are now specified as a list
  1839 of rule sharing the same induction cases. HOL packages usually provide
  1840 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1841 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1842 mutual induction rules differently, i.e. like this:
  1843 
  1844   (induct rule: foo_bar.inducts)
  1845   (induct set: foo bar)
  1846   (induct pred: foo bar)
  1847   (induct type: foo bar)
  1848 
  1849 The ML function ProjectRule.projections turns old-style rules into the
  1850 new format.
  1851 
  1852 * Method "coinduct": dual of induction, see
  1853 src/HOL/Library/Coinductive_List.thy for various examples.
  1854 
  1855 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1856 considered a legacy feature.
  1857 
  1858 * Attribute "symmetric" produces result with standardized schematic
  1859 variables (index 0).  Potential INCOMPATIBILITY.
  1860 
  1861 * Simplifier: by default the simplifier trace only shows top level
  1862 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1863 default. Thus there is less danger of being flooded by the trace. The
  1864 trace indicates where parts have been suppressed.
  1865   
  1866 * Provers/classical: removed obsolete classical version of elim_format
  1867 attribute; classical elim/dest rules are now treated uniformly when
  1868 manipulating the claset.
  1869 
  1870 * Provers/classical: stricter checks to ensure that supplied intro,
  1871 dest and elim rules are well-formed; dest and elim rules must have at
  1872 least one premise.
  1873 
  1874 * Provers/classical: attributes dest/elim/intro take an optional
  1875 weight argument for the rule (just as the Pure versions).  Weights are
  1876 ignored by automated tools, but determine the search order of single
  1877 rule steps.
  1878 
  1879 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1880 where the body does not mention the bound variable.  Note that dummy
  1881 patterns implicitly depend on their context of bounds, which makes
  1882 "{_. _}" match any set comprehension as expected.  Potential
  1883 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1884 constant "_idtdummy" in the binding position.
  1885 
  1886 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1887 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1888 for example "A -> B" => "Pi A (%_. B)".
  1889 
  1890 * Pure: 'class_deps' command visualizes the subclass relation, using
  1891 the graph browser tool.
  1892 
  1893 * Pure: 'print_theory' now suppresses certain internal declarations by
  1894 default; use '!' option for full details.
  1895 
  1896 
  1897 *** HOL ***
  1898 
  1899 * Method "metis" proves goals by applying the Metis general-purpose
  1900 resolution prover (see also http://gilith.com/software/metis/).
  1901 Examples are in the directory MetisExamples.  WARNING: the
  1902 Isabelle/HOL-Metis integration does not yet work properly with
  1903 multi-threading.
  1904   
  1905 * Command 'sledgehammer' invokes external automatic theorem provers as
  1906 background processes.  It generates calls to the "metis" method if
  1907 successful. These can be pasted into the proof.  Users do not have to
  1908 wait for the automatic provers to return.  WARNING: does not really
  1909 work with multi-threading.
  1910 
  1911 * New "auto_quickcheck" feature tests outermost goal statements for
  1912 potential counter-examples.  Controlled by ML references
  1913 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1914 5000 milliseconds).  Fails silently if statements is outside of
  1915 executable fragment, or any other codgenerator problem occurs.
  1916 
  1917 * New constant "undefined" with axiom "undefined x = undefined".
  1918 
  1919 * Added class "HOL.eq", allowing for code generation with polymorphic
  1920 equality.
  1921 
  1922 * Some renaming of class constants due to canonical name prefixing in
  1923 the new 'class' package:
  1924 
  1925     HOL.abs ~> HOL.abs_class.abs
  1926     HOL.divide ~> HOL.divide_class.divide
  1927     0 ~> HOL.zero_class.zero
  1928     1 ~> HOL.one_class.one
  1929     op + ~> HOL.plus_class.plus
  1930     op - ~> HOL.minus_class.minus
  1931     uminus ~> HOL.minus_class.uminus
  1932     op * ~> HOL.times_class.times
  1933     op < ~> HOL.ord_class.less
  1934     op <= > HOL.ord_class.less_eq
  1935     Nat.power ~> Power.power_class.power
  1936     Nat.size ~> Nat.size_class.size
  1937     Numeral.number_of ~> Numeral.number_class.number_of
  1938     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1939     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1940     Orderings.min ~> Orderings.ord_class.min
  1941     Orderings.max ~> Orderings.ord_class.max
  1942     Divides.op div ~> Divides.div_class.div
  1943     Divides.op mod ~> Divides.div_class.mod
  1944     Divides.op dvd ~> Divides.div_class.dvd
  1945 
  1946 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1947 
  1948 a) User-defined constants using any of the names "plus", "minus",
  1949 "times", "less" or "less_eq". The standard syntax translations for
  1950 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1951 names.
  1952 
  1953 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1954 INCOMPATIBILITY: use more specific names.
  1955 
  1956 c) Permutative equations (e.g. "a + b = b + a")
  1957 Since the change of names also changes the order of terms, permutative
  1958 rewrite rules may get applied in a different order. Experience shows
  1959 that this is rarely the case (only two adaptions in the whole Isabelle
  1960 distribution).  INCOMPATIBILITY: rewrite proofs
  1961 
  1962 d) ML code directly refering to constant names
  1963 This in general only affects hand-written proof tactics, simprocs and
  1964 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1965 Consider using @{const_name} antiquotation.
  1966 
  1967 * New class "default" with associated constant "default".
  1968 
  1969 * Function "sgn" is now overloaded and available on int, real, complex
  1970 (and other numeric types), using class "sgn".  Two possible defs of
  1971 sgn are given as equational assumptions in the classes sgn_if and
  1972 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1973 INCOMPATIBILITY.
  1974 
  1975 * Locale "partial_order" now unified with class "order" (cf. theory
  1976 Orderings), added parameter "less".  INCOMPATIBILITY.
  1977 
  1978 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1979 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1980 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1981 
  1982 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1983 changed order of proof goals in instance proofs.
  1984 
  1985 * The transitivity reasoner for partial and linear orders is set up
  1986 for classes "order" and "linorder".  Instances of the reasoner are available
  1987 in all contexts importing or interpreting the corresponding locales.
  1988 Method "order" invokes the reasoner separately; the reasoner
  1989 is also integrated with the Simplifier as a solver.  Diagnostic
  1990 command 'print_orders' shows the available instances of the reasoner
  1991 in the current context.
  1992 
  1993 * Localized monotonicity predicate in theory "Orderings"; integrated
  1994 lemmas max_of_mono and min_of_mono with this predicate.
  1995 INCOMPATIBILITY.
  1996 
  1997 * Formulation of theorem "dense" changed slightly due to integration
  1998 with new class dense_linear_order.
  1999 
  2000 * Uniform lattice theory development in HOL.
  2001 
  2002     constants "meet" and "join" now named "inf" and "sup"
  2003     constant "Meet" now named "Inf"
  2004 
  2005     classes "meet_semilorder" and "join_semilorder" now named
  2006       "lower_semilattice" and "upper_semilattice"
  2007     class "lorder" now named "lattice"
  2008     class "comp_lat" now named "complete_lattice"
  2009 
  2010     Instantiation of lattice classes allows explicit definitions
  2011     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2012 
  2013   INCOMPATIBILITY.  Theorem renames:
  2014 
  2015     meet_left_le            ~> inf_le1
  2016     meet_right_le           ~> inf_le2
  2017     join_left_le            ~> sup_ge1
  2018     join_right_le           ~> sup_ge2
  2019     meet_join_le            ~> inf_sup_ord
  2020     le_meetI                ~> le_infI
  2021     join_leI                ~> le_supI
  2022     le_meet                 ~> le_inf_iff
  2023     le_join                 ~> ge_sup_conv
  2024     meet_idempotent         ~> inf_idem
  2025     join_idempotent         ~> sup_idem
  2026     meet_comm               ~> inf_commute
  2027     join_comm               ~> sup_commute
  2028     meet_leI1               ~> le_infI1
  2029     meet_leI2               ~> le_infI2
  2030     le_joinI1               ~> le_supI1
  2031     le_joinI2               ~> le_supI2
  2032     meet_assoc              ~> inf_assoc
  2033     join_assoc              ~> sup_assoc
  2034     meet_left_comm          ~> inf_left_commute
  2035     meet_left_idempotent    ~> inf_left_idem
  2036     join_left_comm          ~> sup_left_commute
  2037     join_left_idempotent    ~> sup_left_idem
  2038     meet_aci                ~> inf_aci
  2039     join_aci                ~> sup_aci
  2040     le_def_meet             ~> le_iff_inf
  2041     le_def_join             ~> le_iff_sup
  2042     join_absorp2            ~> sup_absorb2
  2043     join_absorp1            ~> sup_absorb1
  2044     meet_absorp1            ~> inf_absorb1
  2045     meet_absorp2            ~> inf_absorb2
  2046     meet_join_absorp        ~> inf_sup_absorb
  2047     join_meet_absorp        ~> sup_inf_absorb
  2048     distrib_join_le         ~> distrib_sup_le
  2049     distrib_meet_le         ~> distrib_inf_le
  2050 
  2051     add_meet_distrib_left   ~> add_inf_distrib_left
  2052     add_join_distrib_left   ~> add_sup_distrib_left
  2053     is_join_neg_meet        ~> is_join_neg_inf
  2054     is_meet_neg_join        ~> is_meet_neg_sup
  2055     add_meet_distrib_right  ~> add_inf_distrib_right
  2056     add_join_distrib_right  ~> add_sup_distrib_right
  2057     add_meet_join_distribs  ~> add_sup_inf_distribs
  2058     join_eq_neg_meet        ~> sup_eq_neg_inf
  2059     meet_eq_neg_join        ~> inf_eq_neg_sup
  2060     add_eq_meet_join        ~> add_eq_inf_sup
  2061     meet_0_imp_0            ~> inf_0_imp_0
  2062     join_0_imp_0            ~> sup_0_imp_0
  2063     meet_0_eq_0             ~> inf_0_eq_0
  2064     join_0_eq_0             ~> sup_0_eq_0
  2065     neg_meet_eq_join        ~> neg_inf_eq_sup
  2066     neg_join_eq_meet        ~> neg_sup_eq_inf
  2067     join_eq_if              ~> sup_eq_if
  2068 
  2069     mono_meet               ~> mono_inf
  2070     mono_join               ~> mono_sup
  2071     meet_bool_eq            ~> inf_bool_eq
  2072     join_bool_eq            ~> sup_bool_eq
  2073     meet_fun_eq             ~> inf_fun_eq
  2074     join_fun_eq             ~> sup_fun_eq
  2075     meet_set_eq             ~> inf_set_eq
  2076     join_set_eq             ~> sup_set_eq
  2077     meet1_iff               ~> inf1_iff
  2078     meet2_iff               ~> inf2_iff
  2079     meet1I                  ~> inf1I
  2080     meet2I                  ~> inf2I
  2081     meet1D1                 ~> inf1D1
  2082     meet2D1                 ~> inf2D1
  2083     meet1D2                 ~> inf1D2
  2084     meet2D2                 ~> inf2D2
  2085     meet1E                  ~> inf1E
  2086     meet2E                  ~> inf2E
  2087     join1_iff               ~> sup1_iff
  2088     join2_iff               ~> sup2_iff
  2089     join1I1                 ~> sup1I1
  2090     join2I1                 ~> sup2I1
  2091     join1I1                 ~> sup1I1
  2092     join2I2                 ~> sup1I2
  2093     join1CI                 ~> sup1CI
  2094     join2CI                 ~> sup2CI
  2095     join1E                  ~> sup1E
  2096     join2E                  ~> sup2E
  2097 
  2098     is_meet_Meet            ~> is_meet_Inf
  2099     Meet_bool_def           ~> Inf_bool_def
  2100     Meet_fun_def            ~> Inf_fun_def
  2101     Meet_greatest           ~> Inf_greatest
  2102     Meet_lower              ~> Inf_lower
  2103     Meet_set_def            ~> Inf_set_def
  2104 
  2105     Sup_def                 ~> Sup_Inf
  2106     Sup_bool_eq             ~> Sup_bool_def
  2107     Sup_fun_eq              ~> Sup_fun_def
  2108     Sup_set_eq              ~> Sup_set_def
  2109 
  2110     listsp_meetI            ~> listsp_infI
  2111     listsp_meet_eq          ~> listsp_inf_eq
  2112 
  2113     meet_min                ~> inf_min
  2114     join_max                ~> sup_max
  2115 
  2116 * Added syntactic class "size"; overloaded constant "size" now has
  2117 type "'a::size ==> bool"
  2118 
  2119 * Internal reorganisation of `size' of datatypes: size theorems
  2120 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2121 simplification rules by default!); theorems "prod.size" now named
  2122 "*.size".
  2123 
  2124 * Class "div" now inherits from class "times" rather than "type".
  2125 INCOMPATIBILITY.
  2126 
  2127 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2128 Linorder etc.  have disappeared; operations defined in terms of
  2129 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2130 
  2131 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2132 
  2133 * HOL-Word: New extensive library and type for generic, fixed size
  2134 machine words, with arithemtic, bit-wise, shifting and rotating
  2135 operations, reflection into int, nat, and bool lists, automation for
  2136 linear arithmetic (by automatic reflection into nat or int), including
  2137 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2138 arithmetic type classes, supporting automatic simplification of
  2139 numerals on all operations.
  2140 
  2141 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2142 
  2143 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2144 
  2145 * Code generator library theories:
  2146   - Code_Integer represents HOL integers by big integer literals in target
  2147     languages.
  2148   - Code_Char represents HOL characters by character literals in target
  2149     languages.
  2150   - Code_Char_chr like Code_Char, but also offers treatment of character
  2151     codes; includes Code_Integer.
  2152   - Executable_Set allows to generate code for finite sets using lists.
  2153   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2154     denominator).
  2155   - Executable_Real implements a subset of real numbers, namly those
  2156     representable by rational numbers.
  2157   - Efficient_Nat implements natural numbers by integers, which in general will
  2158     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2159     includes Code_Integer.
  2160   - Code_Index provides an additional datatype index which is mapped to
  2161     target-language built-in integers.
  2162   - Code_Message provides an additional datatype message_string which is isomorphic to
  2163     strings; messages are mapped to target-language strings.
  2164 
  2165 * New package for inductive predicates
  2166 
  2167   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2168 
  2169     inductive
  2170       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2171       for z_1 :: U_1 and ... and z_n :: U_m
  2172     where
  2173       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2174     | ...
  2175 
  2176   with full support for type-inference, rather than
  2177 
  2178     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2179 
  2180     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2181     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2182 
  2183     inductive "s z_1 ... z_m"
  2184     intros
  2185       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2186       ...
  2187 
  2188   For backward compatibility, there is a wrapper allowing inductive
  2189   sets to be defined with the new package via
  2190 
  2191     inductive_set
  2192       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2193       for z_1 :: U_1 and ... and z_n :: U_m
  2194     where
  2195       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2196     | ...
  2197 
  2198   or
  2199 
  2200     inductive_set
  2201       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2202       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2203       for z_1 :: U_1 and ... and z_n :: U_m
  2204     where
  2205       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2206     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2207     | ...
  2208 
  2209   if the additional syntax "p ..." is required.
  2210 
  2211   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2212   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2213 
  2214   INCOMPATIBILITIES:
  2215 
  2216   - Since declaration and definition of inductive sets or predicates
  2217     is no longer separated, abbreviations involving the newly
  2218     introduced sets or predicates must be specified together with the
  2219     introduction rules after the 'where' keyword (see above), rather
  2220     than before the actual inductive definition.
  2221 
  2222   - The variables in induction and elimination rules are now
  2223     quantified in the order of their occurrence in the introduction
  2224     rules, rather than in alphabetical order. Since this may break
  2225     some proofs, these proofs either have to be repaired, e.g. by
  2226     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2227     statements of the form
  2228 
  2229       case (rule_i a_i_1 ... a_i_{k_i})
  2230 
  2231     or the old order of quantification has to be restored by explicitly adding
  2232     meta-level quantifiers in the introduction rules, i.e.
  2233 
  2234       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2235 
  2236   - The format of the elimination rules is now
  2237 
  2238       p z_1 ... z_m x_1 ... x_n ==>
  2239         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2240         ==> ... ==> P
  2241 
  2242     for predicates and
  2243 
  2244       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2245         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2246         ==> ... ==> P
  2247 
  2248     for sets rather than
  2249 
  2250       x : s z_1 ... z_m ==>
  2251         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2252         ==> ... ==> P
  2253 
  2254     This may require terms in goals to be expanded to n-tuples
  2255     (e.g. using case_tac or simplification with the split_paired_all
  2256     rule) before the above elimination rule is applicable.
  2257 
  2258   - The elimination or case analysis rules for (mutually) inductive
  2259     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2260     list of rules "p_1_..._p_k.elims" is no longer available.
  2261 
  2262 * New package "function"/"fun" for general recursive functions,
  2263 supporting mutual and nested recursion, definitions in local contexts,
  2264 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2265 for small examples, and the separate tutorial on the function
  2266 package. The old recdef "package" is still available as before, but
  2267 users are encouraged to use the new package.
  2268 
  2269 * Method "lexicographic_order" automatically synthesizes termination
  2270 relations as lexicographic combinations of size measures. 
  2271 
  2272 * Case-expressions allow arbitrary constructor-patterns (including
  2273 "_") and take their order into account, like in functional
  2274 programming.  Internally, this is translated into nested
  2275 case-expressions; missing cases are added and mapped to the predefined
  2276 constant "undefined". In complicated cases printing may no longer show
  2277 the original input but the internal form. Lambda-abstractions allow
  2278 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2279 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2280 variable.
  2281 
  2282 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2283 is an abbreviation for "of_nat :: nat => int". The simplification
  2284 rules for "of_nat" have been changed to work like "int" did
  2285 previously.  Potential INCOMPATIBILITY:
  2286   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2287   - of_nat_diff and of_nat_mult are no longer default simp rules
  2288 
  2289 * Method "algebra" solves polynomial equations over (semi)rings using
  2290 Groebner bases. The (semi)ring structure is defined by locales and the
  2291 tool setup depends on that generic context. Installing the method for
  2292 a specific type involves instantiating the locale and possibly adding
  2293 declarations for computation on the coefficients.  The method is
  2294 already instantiated for natural numbers and for the axiomatic class
  2295 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2296 CALCULEMUS 2007 for the general principles underlying this
  2297 architecture of context-aware proof-tools.
  2298 
  2299 * Method "ferrack" implements quantifier elimination over
  2300 special-purpose dense linear orders using locales (analogous to
  2301 "algebra"). The method is already installed for class
  2302 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2303 rat, etc.
  2304 
  2305 * Former constant "List.op @" now named "List.append".  Use ML
  2306 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2307 circumvent possible incompatibilities when working on ML level.
  2308 
  2309 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2310 
  2311 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2312 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2313 
  2314 * New syntax for Haskell-like list comprehension (input only), eg.
  2315 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2316 
  2317 * The special syntax for function "filter" has changed from [x :
  2318 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2319 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2320 
  2321 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2322 defined on nat only, as an abbreviation for [a..<Suc b]
  2323 INCOMPATIBILITY.
  2324 
  2325 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2326 
  2327 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2328 
  2329 * New lemma collection field_simps (an extension of ring_simps) for
  2330 manipulating (in)equations involving division. Multiplies with all
  2331 denominators that can be proved to be non-zero (in equations) or
  2332 positive/negative (in inequations).
  2333 
  2334 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2335 have been improved and renamed to ring_simps, group_simps and
  2336 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2337 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2338 
  2339 * Theory Library/Commutative_Ring: switched from recdef to function
  2340 package; constants add, mul, pow now curried.  Infix syntax for
  2341 algebraic operations.
  2342 
  2343 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2344 INCOMPATIBILITY.
  2345 
  2346 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2347 INCOMPATIBILITY.
  2348 
  2349 * HOL/records: generalised field-update to take a function on the
  2350 field rather than the new value: r(|A := x|) is translated to A_update
  2351 (K x) r The K-combinator that is internally used is called K_record.
  2352 INCOMPATIBILITY: Usage of the plain update functions has to be
  2353 adapted.
  2354  
  2355 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2356 * x = 0, which are required for a semiring.  Richer structures do not
  2357 inherit from semiring_0 anymore, because this property is a theorem
  2358 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2359 there is more to prove, but this is mostly trivial.
  2360 
  2361 * Class "recpower" is generalized to arbitrary monoids, not just
  2362 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2363 commutativity or semiring properties additionally.
  2364 
  2365 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2366 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2367 better use 'abbreviation'.
  2368 
  2369 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2370 
  2371 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2372 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2373 significant changes for setting up numeral syntax for types:
  2374   - New constants Numeral.pred and Numeral.succ instead
  2375       of former Numeral.bin_pred and Numeral.bin_succ.
  2376   - Use integer operations instead of bin_add, bin_mult and so on.
  2377   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2378   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2379 
  2380 See src/HOL/Integ/IntArith.thy for an example setup.
  2381 
  2382 * Command 'normal_form' computes the normal form of a term that may
  2383 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2384 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2385 heavy-duty computations because the functions are compiled to ML
  2386 first.  Correspondingly, a method "normalization" is provided.  See
  2387 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2388 
  2389 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2390 25 like -->); output depends on the "iff" print_mode, the default is
  2391 "A = B" (with priority 50).
  2392 
  2393 * Relations less (<) and less_eq (<=) are also available on type bool.
  2394 Modified syntax to disallow nesting without explicit parentheses,
  2395 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2396 INCOMPATIBILITY.
  2397 
  2398 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2399 
  2400 * Relation composition operator "op O" now has precedence 75 and binds
  2401 stronger than union and intersection. INCOMPATIBILITY.
  2402 
  2403 * The old set interval syntax "{m..n(}" (and relatives) has been
  2404 removed.  Use "{m..<n}" (and relatives) instead.
  2405 
  2406 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2407 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2408 ``declare [[simproc del: neq]]''.
  2409 
  2410 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2411 True/False.
  2412 
  2413 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2414 
  2415 * Theorem setsum_mult renamed to setsum_right_distrib.
  2416 
  2417 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2418 ``rule'' method.
  2419 
  2420 * Reimplemented methods "sat" and "satx", with several improvements:
  2421 goals no longer need to be stated as "<prems> ==> False", equivalences
  2422 (i.e. "=" on type bool) are handled, variable names of the form
  2423 "lit_<n>" are no longer reserved, significant speedup.
  2424 
  2425 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2426 zChaff is still supported as well.
  2427 
  2428 * 'inductive' and 'datatype': provide projections of mutual rules,
  2429 bundled as foo_bar.inducts;
  2430 
  2431 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2432 Library.
  2433 
  2434 * Library: moved theory Accessible_Part to main HOL.
  2435 
  2436 * Library: added theory Coinductive_List of potentially infinite lists
  2437 as greatest fixed-point.
  2438 
  2439 * Library: added theory AssocList which implements (finite) maps as
  2440 association lists.
  2441 
  2442 * Method "evaluation" solves goals (i.e. a boolean expression)
  2443 efficiently by compiling it to ML.  The goal is "proved" (via an
  2444 oracle) if it evaluates to True.
  2445 
  2446 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2447 also when invoked by the simplifier.  This results in the Simplifier
  2448 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2449 Configuration option fast_arith_split_limit=0 recovers the old
  2450 behavior.
  2451 
  2452 * Support for hex (0x20) and binary (0b1001) numerals.
  2453 
  2454 * New method: reify eqs (t), where eqs are equations for an
  2455 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2456 parameter, computes a term s::'b and a list xs::'a list and proves the
  2457 theorem I xs s = t. This is also known as reification or quoting. The
  2458 resulting theorem is applied to the subgoal to substitute t with I xs
  2459 s.  If t is omitted, the subgoal itself is reified.
  2460 
  2461 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2462 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2463 where f is supposed to be a computable function (in the sense of code
  2464 generattion). The method uses reify to compute s and xs as above then
  2465 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2466 r and finally gets the theorem t = r, which is again applied to the
  2467 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2468 
  2469 * Reflection: Automatic reification now handels binding, an example is
  2470 available in src/HOL/ex/ReflectionEx.thy
  2471 
  2472 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2473 command 'statespace' that is similar to 'record', but introduces an
  2474 abstract specification based on the locale infrastructure instead of
  2475 HOL types.  This leads to extra flexibility in composing state spaces,
  2476 in particular multiple inheritance and renaming of components.
  2477 
  2478 
  2479 *** HOL-Complex ***
  2480 
  2481 * Hyperreal: Functions root and sqrt are now defined on negative real
  2482 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2483 Nonnegativity side conditions have been removed from many lemmas, so
  2484 that more subgoals may now be solved by simplification; potential
  2485 INCOMPATIBILITY.
  2486 
  2487 * Real: new type classes formalize real normed vector spaces and
  2488 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2489 and norm :: 'a => real.
  2490 
  2491 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2492 reals into other types. The overloaded constant Reals :: 'a set is now
  2493 defined as range of_real; potential INCOMPATIBILITY.
  2494 
  2495 * Real: proper support for ML code generation, including 'quickcheck'.
  2496 Reals are implemented as arbitrary precision rationals.
  2497 
  2498 * Hyperreal: Several constants that previously worked only for the
  2499 reals have been generalized, so they now work over arbitrary vector
  2500 spaces. Type annotations may need to be added in some cases; potential
  2501 INCOMPATIBILITY.
  2502 
  2503   Infinitesimal  :: ('a::real_normed_vector) star set
  2504   HFinite        :: ('a::real_normed_vector) star set
  2505   HInfinite      :: ('a::real_normed_vector) star set
  2506   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2507   monad          :: ('a::real_normed_vector) star => 'a star set
  2508   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2509   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2510   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2511   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2512   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2513   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2514   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2515   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2516   sgn            :: 'a::real_normed_vector => 'a
  2517   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2518 
  2519 * Complex: Some complex-specific constants are now abbreviations for
  2520 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2521 hnorm.  Other constants have been entirely removed in favor of the
  2522 polymorphic versions (INCOMPATIBILITY):
  2523 
  2524   approx        <-- capprox
  2525   HFinite       <-- CFinite
  2526   HInfinite     <-- CInfinite
  2527   Infinitesimal <-- CInfinitesimal
  2528   monad         <-- cmonad
  2529   galaxy        <-- cgalaxy
  2530   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2531   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2532   (ns)deriv     <-- (ns)cderiv
  2533 
  2534 
  2535 *** HOL-Algebra ***
  2536 
  2537 * Formalisation of ideals and the quotient construction over rings.
  2538 
  2539 * Order and lattice theory no longer based on records.
  2540 INCOMPATIBILITY.
  2541 
  2542 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2543 greatest_closed.  INCOMPATIBILITY.
  2544 
  2545 * Method algebra is now set up via an attribute.  For examples see
  2546 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2547 of algebraic structures.
  2548 
  2549 * Renamed theory CRing to Ring.
  2550 
  2551 
  2552 *** HOL-Nominal ***
  2553 
  2554 * Substantial, yet incomplete support for nominal datatypes (binding
  2555 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2556 src/HOL/Nominal/Examples.  Prospective users should consult
  2557 http://isabelle.in.tum.de/nominal/
  2558 
  2559 
  2560 *** ML ***
  2561 
  2562 * ML basics: just one true type int, which coincides with IntInf.int
  2563 (even on SML/NJ).
  2564 
  2565 * ML within Isar: antiquotations allow to embed statically-checked
  2566 formal entities in the source, referring to the context available at
  2567 compile-time.  For example:
  2568 
  2569 ML {* @{sort "{zero,one}"} *}
  2570 ML {* @{typ "'a => 'b"} *}
  2571 ML {* @{term "%x. x"} *}
  2572 ML {* @{prop "x == y"} *}
  2573 ML {* @{ctyp "'a => 'b"} *}
  2574 ML {* @{cterm "%x. x"} *}
  2575 ML {* @{cprop "x == y"} *}
  2576 ML {* @{thm asm_rl} *}
  2577 ML {* @{thms asm_rl} *}
  2578 ML {* @{type_name c} *}
  2579 ML {* @{type_syntax c} *}
  2580 ML {* @{const_name c} *}
  2581 ML {* @{const_syntax c} *}
  2582 ML {* @{context} *}
  2583 ML {* @{theory} *}
  2584 ML {* @{theory Pure} *}
  2585 ML {* @{theory_ref} *}
  2586 ML {* @{theory_ref Pure} *}
  2587 ML {* @{simpset} *}
  2588 ML {* @{claset} *}
  2589 ML {* @{clasimpset} *}
  2590 
  2591 The same works for sources being ``used'' within an Isar context.
  2592 
  2593 * ML in Isar: improved error reporting; extra verbosity with
  2594 ML_Context.trace enabled.
  2595 
  2596 * Pure/General/table.ML: the join operations now works via exceptions
  2597 DUP/SAME instead of type option. This is simpler in simple cases, and
  2598 admits slightly more efficient complex applications.
  2599 
  2600 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2601 use Context.generic instead of just theory.
  2602 
  2603 * Pure: datatype Context.generic joins theory/Proof.context and
  2604 provides some facilities for code that works in either kind of
  2605 context, notably GenericDataFun for uniform theory and proof data.
  2606 
  2607 * Pure: simplified internal attribute type, which is now always
  2608 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2609 local (Proof.context) attributes have been discontinued, while
  2610 minimizing code duplication. Thm.rule_attribute and
  2611 Thm.declaration_attribute build canonical attributes; see also structure
  2612 Context for further operations on Context.generic, notably
  2613 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2614 declarations and definitions.
  2615 
  2616 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2617 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2618 init only required for impure data. INCOMPATIBILITY: empty really need
  2619 to be empty (no dependencies on theory content!)
  2620 
  2621 * Pure/kernel: consts certification ignores sort constraints given in
  2622 signature declarations. (This information is not relevant to the
  2623 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2624 potential INCOMPATIBILITY.
  2625 
  2626 * Pure: axiomatic type classes are now purely definitional, with
  2627 explicit proofs of class axioms and super class relations performed
  2628 internally. See Pure/axclass.ML for the main internal interfaces --
  2629 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2630 AxClass.axiomatize_class/classrel/arity supersede
  2631 Sign.add_classes/classrel/arities.
  2632 
  2633 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2634 global/local versions on theory vs. Proof.context have been
  2635 discontinued; Attrib.syntax and Method.syntax have been adapted
  2636 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2637 attributes, methods, etc.
  2638 
  2639 * Pure: several functions of signature "... -> theory -> theory * ..."
  2640 have been reoriented to "... -> theory -> ... * theory" in order to
  2641 allow natural usage in combination with the ||>, ||>>, |-> and
  2642 fold_map combinators.
  2643 
  2644 * Pure: official theorem names (closed derivations) and additional
  2645 comments (tags) are now strictly separate.  Name hints -- which are
  2646 maintained as tags -- may be attached any time without affecting the
  2647 derivation.
  2648 
  2649 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2650 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2651 achieve the old behaviour.
  2652 
  2653 * Pure: the "Goal" constant is now called "prop", supporting a
  2654 slightly more general idea of ``protecting'' meta-level rule
  2655 statements.
  2656 
  2657 * Pure: Logic.(un)varify only works in a global context, which is now
  2658 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2659 Logic.legacy_(un)varify as temporary workaround.
  2660 
  2661 * Pure: structure Name provides scalable operations for generating
  2662 internal variable names, notably Name.variants etc.  This replaces
  2663 some popular functions from term.ML:
  2664 
  2665   Term.variant		->  Name.variant
  2666   Term.variantlist	->  Name.variant_list
  2667   Term.invent_names	->  Name.invent_list
  2668 
  2669 Note that low-level renaming rarely occurs in new code -- operations
  2670 from structure Variable are used instead (see below).
  2671 
  2672 * Pure: structure Variable provides fundamental operations for proper
  2673 treatment of fixed/schematic variables in a context.  For example,
  2674 Variable.import introduces fixes for schematics of given facts and
  2675 Variable.export reverses the effect (up to renaming) -- this replaces
  2676 various freeze_thaw operations.
  2677 
  2678 * Pure: structure Goal provides simple interfaces for
  2679 init/conclude/finish and tactical prove operations (replacing former
  2680 Tactic.prove).  Goal.prove is the canonical way to prove results
  2681 within a given context; Goal.prove_global is a degraded version for
  2682 theory level goals, including a global Drule.standard.  Note that
  2683 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2684 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2685 in a locale context).
  2686 
  2687 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2688 and type checking (Syntax.check_term etc.), with common combinations
  2689 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2690 which are considered legacy and await removal.
  2691 
  2692 * Pure/Syntax: generic interfaces for type unchecking
  2693 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2694 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2695 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2696 available for convenience, but refer to the very same operations using
  2697 a mere theory instead of a full context.
  2698 
  2699 * Isar: simplified treatment of user-level errors, using exception
  2700 ERROR of string uniformly.  Function error now merely raises ERROR,
  2701 without any side effect on output channels.  The Isar toplevel takes
  2702 care of proper display of ERROR exceptions.  ML code may use plain
  2703 handle/can/try; cat_error may be used to concatenate errors like this:
  2704 
  2705   ... handle ERROR msg => cat_error msg "..."
  2706 
  2707 Toplevel ML code (run directly or through the Isar toplevel) may be
  2708 embedded into the Isar toplevel with exception display/debug like
  2709 this:
  2710 
  2711   Isar.toplevel (fn () => ...)
  2712 
  2713 INCOMPATIBILITY, removed special transform_error facilities, removed
  2714 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2715 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2716 -- use plain ERROR instead.
  2717 
  2718 * Isar: theory setup now has type (theory -> theory), instead of a
  2719 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2720 
  2721 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2722 ProofContext.debug/verbose flags.
  2723 
  2724 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2725 theory before entering a proof state.  Transactions now always see a
  2726 quasi-functional intermediate checkpoint, both in interactive and
  2727 batch mode.
  2728 
  2729 * Isar: simplified interfaces for outer syntax.  Renamed
  2730 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2731 OuterSyntax.add_parsers -- this functionality is now included in
  2732 OuterSyntax.command etc.  INCOMPATIBILITY.
  2733 
  2734 * Simplifier: the simpset of a running simplification process now
  2735 contains a proof context (cf. Simplifier.the_context), which is the
  2736 very context that the initial simpset has been retrieved from (by
  2737 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2738 (solver, looper etc.) may depend on arbitrary proof data.
  2739 
  2740 * Simplifier.inherit_context inherits the proof context (plus the
  2741 local bounds) of the current simplification process; any simproc
  2742 etc. that calls the Simplifier recursively should do this!  Removed
  2743 former Simplifier.inherit_bounds, which is already included here --
  2744 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2745 specify an explicit context using Simplifier.context/theory_context.
  2746 
  2747 * Simplifier/Classical Reasoner: more abstract interfaces
  2748 change_simpset/claset for modifying the simpset/claset reference of a
  2749 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2750 INCOMPATIBILITY.
  2751 
  2752 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2753 "Trueprop" etc.
  2754 
  2755 
  2756 *** System ***
  2757 
  2758 * settings: the default heap location within ISABELLE_HOME_USER now
  2759 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2760 Isabelle installations.
  2761 
  2762 * isabelle-process: option -S (secure mode) disables some critical
  2763 operations, notably runtime compilation and evaluation of ML source
  2764 code.
  2765 
  2766 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2767 
  2768 * Support for parallel execution, using native multicore support of
  2769 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2770 independent theories, according to the given theory header
  2771 specifications. The maximum number of worker threads is specified via
  2772 usedir option -M or the "max-threads" setting in Proof General. A
  2773 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2774 to 6 on a 8-core machine.  User-code needs to observe certain
  2775 guidelines for thread-safe programming, see appendix A in the Isar
  2776 Implementation manual.
  2777 
  2778 
  2779 
  2780 New in Isabelle2005 (October 2005)
  2781 ----------------------------------
  2782 
  2783 *** General ***
  2784 
  2785 * Theory headers: the new header syntax for Isar theories is
  2786 
  2787   theory <name>
  2788   imports <theory1> ... <theoryN>
  2789   uses <file1> ... <fileM>
  2790   begin
  2791 
  2792 where the 'uses' part is optional.  The previous syntax
  2793 
  2794   theory <name> = <theory1> + ... + <theoryN>:
  2795 
  2796 will disappear in the next release.  Use isatool fixheaders to convert
  2797 existing theory files.  Note that there is no change in ancient
  2798 non-Isar theories now, but these will disappear soon.
  2799 
  2800 * Theory loader: parent theories can now also be referred to via
  2801 relative and absolute paths.
  2802 
  2803 * Command 'find_theorems' searches for a list of criteria instead of a
  2804 list of constants. Known criteria are: intro, elim, dest, name:string,
  2805 simp:term, and any term. Criteria can be preceded by '-' to select
  2806 theorems that do not match. Intro, elim, dest select theorems that
  2807 match the current goal, name:s selects theorems whose fully qualified
  2808 name contain s, and simp:term selects all simplification rules whose
  2809 lhs match term.  Any other term is interpreted as pattern and selects
  2810 all theorems matching the pattern. Available in ProofGeneral under
  2811 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2812 
  2813   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2814 
  2815 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2816 matching the current goal as introduction rule and not having "HOL."
  2817 in their name (i.e. not being defined in theory HOL).
  2818 
  2819 * Command 'thms_containing' has been discontinued in favour of
  2820 'find_theorems'; INCOMPATIBILITY.
  2821 
  2822 * Communication with Proof General is now 8bit clean, which means that
  2823 Unicode text in UTF-8 encoding may be used within theory texts (both
  2824 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2825 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2826 
  2827   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2828   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2829 
  2830 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2831 Classical Reasoner.  Typical big applications run around 2 times
  2832 faster.
  2833 
  2834 
  2835 *** Document preparation ***
  2836 
  2837 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2838 of raw sources.  Only those symbols that do not require additional
  2839 LaTeX packages (depending on comments in isabellesym.sty) are
  2840 displayed properly, everything else is left verbatim.  isatool display
  2841 and isatool print are used as front ends (these are subject to the
  2842 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2843 
  2844 * Command tags control specific markup of certain regions of text,
  2845 notably folding and hiding.  Predefined tags include "theory" (for
  2846 theory begin and end), "proof" for proof commands, and "ML" for
  2847 commands involving ML code; the additional tags "visible" and
  2848 "invisible" are unused by default.  Users may give explicit tag
  2849 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2850 interpretation of tags is determined by the LaTeX job during document
  2851 preparation: see option -V of isatool usedir, or options -n and -t of
  2852 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2853 \isadroptag.
  2854 
  2855 Several document versions may be produced at the same time via isatool
  2856 usedir (the generated index.html will link all of them).  Typical
  2857 specifications include ''-V document=theory,proof,ML'' to present
  2858 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2859 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2860 these parts without any formal replacement text.  The Isabelle site
  2861 default settings produce ''document'' and ''outline'' versions as
  2862 specified above.
  2863 
  2864 * Several new antiquotations:
  2865 
  2866   @{term_type term} prints a term with its type annotated;
  2867 
  2868   @{typeof term} prints the type of a term;
  2869 
  2870   @{const const} is the same as @{term const}, but checks that the
  2871   argument is a known logical constant;
  2872 
  2873   @{term_style style term} and @{thm_style style thm} print a term or
  2874   theorem applying a "style" to it
  2875 
  2876   @{ML text}
  2877 
  2878 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2879 definitions, equations, inequations etc., 'concl' printing only the
  2880 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2881 to print the specified premise.  TermStyle.add_style provides an ML
  2882 interface for introducing further styles.  See also the "LaTeX Sugar"
  2883 document practical applications.  The ML antiquotation prints
  2884 type-checked ML expressions verbatim.
  2885 
  2886 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2887 and 'text' support optional locale specification '(in loc)', which
  2888 specifies the default context for interpreting antiquotations.  For
  2889 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2890 
  2891 * Option 'locale=NAME' of antiquotations specifies an alternative
  2892 context interpreting the subsequent argument.  For example: @{thm
  2893 [locale=lattice] inf_assoc}.
  2894 
  2895 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2896 a proof context.
  2897 
  2898 * Proper output of antiquotations for theory commands involving a
  2899 proof context (such as 'locale' or 'theorem (in loc) ...').
  2900 
  2901 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2902 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2903 
  2904 * isatool usedir: new option -C (default true) controls whether option
  2905 -D should include a copy of the original document directory; -C false
  2906 prevents unwanted effects such as copying of administrative CVS data.
  2907 
  2908 
  2909 *** Pure ***
  2910 
  2911 * Considerably improved version of 'constdefs' command.  Now performs
  2912 automatic type-inference of declared constants; additional support for
  2913 local structure declarations (cf. locales and HOL records), see also
  2914 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2915 sequential dependencies of definitions within a single 'constdefs'
  2916 section; moreover, the declared name needs to be an identifier.  If
  2917 all fails, consider to fall back on 'consts' and 'defs' separately.
  2918 
  2919 * Improved indexed syntax and implicit structures.  First of all,
  2920 indexed syntax provides a notational device for subscripted
  2921 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2922 expressions.  Secondly, in a local context with structure
  2923 declarations, number indexes \<^sub>n or the empty index (default
  2924 number 1) refer to a certain fixed variable implicitly; option
  2925 show_structs controls printing of implicit structures.  Typical
  2926 applications of these concepts involve record types and locales.
  2927 
  2928 * New command 'no_syntax' removes grammar declarations (and
  2929 translations) resulting from the given syntax specification, which is
  2930 interpreted in the same manner as for the 'syntax' command.
  2931 
  2932 * 'Advanced' translation functions (parse_translation etc.) may depend
  2933 on the signature of the theory context being presently used for
  2934 parsing/printing, see also isar-ref manual.
  2935 
  2936 * Improved 'oracle' command provides a type-safe interface to turn an
  2937 ML expression of type theory -> T -> term into a primitive rule of
  2938 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2939 is already included here); see also FOL/ex/IffExample.thy;
  2940 INCOMPATIBILITY.
  2941 
  2942 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2943 before); "cI" is no longer bound, use "c.intro" instead.
  2944 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2945 axclasses vs. locales.
  2946 
  2947 * Improved internal renaming of symbolic identifiers -- attach primes
  2948 instead of base 26 numbers.
  2949 
  2950 * New flag show_question_marks controls printing of leading question
  2951 marks in schematic variable names.
  2952 
  2953 * In schematic variable names, *any* symbol following \<^isub> or
  2954 \<^isup> is now treated as part of the base name.  For example, the
  2955 following works without printing of awkward ".0" indexes:
  2956 
  2957   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2958     by simp
  2959 
  2960 * Inner syntax includes (*(*nested*) comments*).
  2961 
  2962 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2963 annotations as "(00...)".
  2964 
  2965 * Clear separation of logical types and nonterminals, where the latter
  2966 may only occur in 'syntax' specifications or type abbreviations.
  2967 Before that distinction was only partially implemented via type class
  2968 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2969 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2970 exotic syntax specifications may require further adaption
  2971 (e.g. Cube/Cube.thy).
  2972 
  2973 * Removed obsolete type class "logic", use the top sort {} instead.
  2974 Note that non-logical types should be declared as 'nonterminals'
  2975 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2976 specifications.
  2977 
  2978 * Attributes 'induct' and 'cases': type or set names may now be
  2979 locally fixed variables as well.
  2980 
  2981 * Simplifier: can now control the depth to which conditional rewriting
  2982 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2983 Limit.
  2984 
  2985 * Simplifier: simplification procedures may now take the current
  2986 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2987 interface), which is very useful for calling the Simplifier
  2988 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2989 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2990 low-level mk_simproc no longer applies Logic.varify internally, to
  2991 allow for use in a context of fixed variables.
  2992 
  2993 * thin_tac now works even if the assumption being deleted contains !!
  2994 or ==>.  More generally, erule now works even if the major premise of
  2995 the elimination rule contains !! or ==>.
  2996 
  2997 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2998 
  2999 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3000 from Pure, which contains all common declarations already.  Both
  3001 theories are defined via plain Isabelle/Isar .thy files.
  3002 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3003 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3004 use isatool fixcpure to adapt your theory and ML sources.
  3005 
  3006 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3007 selections of theorems in named facts via index ranges.
  3008 
  3009 * 'print_theorems': in theory mode, really print the difference
  3010 wrt. the last state (works for interactive theory development only),
  3011 in proof mode print all local facts (cf. 'print_facts');
  3012 
  3013 * 'hide': option '(open)' hides only base names.
  3014 
  3015 * More efficient treatment of intermediate checkpoints in interactive
  3016 theory development.
  3017 
  3018 * Code generator is now invoked via code_module (incremental code
  3019 generation) and code_library (modular code generation, ML structures
  3020 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3021 must be quoted when used as identifiers.
  3022 
  3023 * New 'value' command for reading, evaluating and printing terms using
  3024 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3025 quoted when used as identifier.
  3026 
  3027 
  3028 *** Locales ***
  3029 
  3030 * New commands for the interpretation of locale expressions in
  3031 theories (1), locales (2) and proof contexts (3).  These generate
  3032 proof obligations from the expression specification.  After the
  3033 obligations have been discharged, theorems of the expression are added
  3034 to the theory, target locale or proof context.  The synopsis of the
  3035 commands is a follows:
  3036 
  3037   (1) interpretation expr inst
  3038   (2) interpretation target < expr
  3039   (3) interpret expr inst
  3040 
  3041 Interpretation in theories and proof contexts require a parameter
  3042 instantiation of terms from the current context.  This is applied to
  3043 specifications and theorems of the interpreted expression.
  3044 Interpretation in locales only permits parameter renaming through the
  3045 locale expression.  Interpretation is smart in that interpretations
  3046 that are active already do not occur in proof obligations, neither are
  3047 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3048 inspect active interpretations of a particular locale.  For details,
  3049 see the Isar Reference manual.  Examples can be found in
  3050 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3051 
  3052 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3053 'interpret' instead.
  3054 
  3055 * New context element 'constrains' for adding type constraints to
  3056 parameters.
  3057 
  3058 * Context expressions: renaming of parameters with syntax
  3059 redeclaration.
  3060 
  3061 * Locale declaration: 'includes' disallowed.
  3062 
  3063 * Proper static binding of attribute syntax -- i.e. types / terms /
  3064 facts mentioned as arguments are always those of the locale definition
  3065 context, independently of the context of later invocations.  Moreover,
  3066 locale operations (renaming and type / term instantiation) are applied
  3067 to attribute arguments as expected.
  3068 
  3069 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3070 actual attributes; rare situations may require Attrib.attribute to
  3071 embed those attributes into Attrib.src that lack concrete syntax.
  3072 Attribute implementations need to cooperate properly with the static
  3073 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3074 Attrib.XXX_thm etc. already do the right thing without further
  3075 intervention.  Only unusual applications -- such as "where" or "of"
  3076 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3077 on the context and the facts involved -- may have to assign parsed
  3078 values to argument tokens explicitly.
  3079 
  3080 * Changed parameter management in theorem generation for long goal
  3081 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3082 theorem statement in rare situations.
  3083 
  3084 * Locale inspection command 'print_locale' omits notes elements.  Use
  3085 'print_locale!' to have them included in the output.
  3086 
  3087 
  3088 *** Provers ***
  3089 
  3090 * Provers/hypsubst.ML: improved version of the subst method, for
  3091 single-step rewriting: it now works in bound variable contexts. New is
  3092 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3093 rewrite a different subterm than the original subst method, which is
  3094 still available as 'simplesubst'.
  3095 
  3096 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3097 and quasi orders.
  3098 
  3099 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3100 reflexive-transitive closure of relations.
  3101 
  3102 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3103 limit (previously hard-coded with a value of 20) user-definable.
  3104 
  3105 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3106 is peformed already.  Object-logics merely need to finish their
  3107 initial simpset configuration as before.  INCOMPATIBILITY.
  3108 
  3109 
  3110 *** HOL ***
  3111 
  3112 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3113 
  3114   syntax (epsilon)
  3115     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3116 
  3117 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3118 and x-symbol; use option '-m epsilon' to get it actually printed.
  3119 Moreover, the mathematically important symbolic identifier \<epsilon>
  3120 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3121 
  3122 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3123 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3124 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3125 support corresponding Isar calculations.
  3126 
  3127 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3128 instead of ":".
  3129 
  3130 * theory SetInterval: changed the syntax for open intervals:
  3131 
  3132   Old       New
  3133   {..n(}    {..<n}
  3134   {)n..}    {n<..}
  3135   {m..n(}   {m..<n}
  3136   {)m..n}   {m<..n}
  3137   {)m..n(}  {m<..<n}
  3138 
  3139 The old syntax is still supported but will disappear in the next
  3140 release.  For conversion use the following Emacs search and replace
  3141 patterns (these are not perfect but work quite well):
  3142 
  3143   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3144   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3145 
  3146 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3147 equalities in commutative rings; method 'algebra' provides a generic
  3148 interface.
  3149 
  3150 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3151 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3152 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3153 be a tuple pattern.
  3154 
  3155 Some new syntax forms are available:
  3156 
  3157   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3158   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3159   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3160   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3161 
  3162 The latter form "\<Sum>x < k. e" used to be based on a separate
  3163 function "Summation", which has been discontinued.
  3164 
  3165 * theory Finite_Set: in structured induction proofs, the insert case
  3166 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3167 (insert F x)'.
  3168 
  3169 * The 'refute' command has been extended to support a much larger
  3170 fragment of HOL, including axiomatic type classes, constdefs and
  3171 typedefs, inductive datatypes and recursion.
  3172 
  3173 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3174 Requires zChaff with proof generation to be installed.  See
  3175 HOL/ex/SAT_Examples.thy for examples.
  3176 
  3177 * Datatype induction via method 'induct' now preserves the name of the
  3178 induction variable. For example, when proving P(xs::'a list) by
  3179 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3180 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3181 in unstructured proof scripts.
  3182 
  3183 * Reworked implementation of records.  Improved scalability for
  3184 records with many fields, avoiding performance problems for type
  3185 inference. Records are no longer composed of nested field types, but
  3186 of nested extension types. Therefore the record type only grows linear
  3187 in the number of extensions and not in the number of fields.  The
  3188 top-level (users) view on records is preserved.  Potential
  3189 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3190 old record representation. The type generated for a record is called
  3191 <record_name>_ext_type.
  3192 
  3193 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3194 proofs triggered by a record definition or a simproc (if
  3195 quick_and_dirty is enabled).  Definitions of large records can take
  3196 quite long.
  3197 
  3198 New simproc record_upd_simproc for simplification of multiple record
  3199 updates enabled by default.  Moreover, trivial updates are also
  3200 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3201 occasionally, since simplification is more powerful by default.
  3202 
  3203 * typedef: proper support for polymorphic sets, which contain extra
  3204 type-variables in the term.
  3205 
  3206 * Simplifier: automatically reasons about transitivity chains
  3207 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3208 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3209 old proofs break occasionally as simplification may now solve more
  3210 goals than previously.
  3211 
  3212 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3213 present.  Works for all partial orders (class "order"), in particular
  3214 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3215 just like y <= x.
  3216 
  3217 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3218 bound variable or a constant then the let is unfolded.  Otherwise
  3219 first a is simplified to b, and then f b is simplified to g. If
  3220 possible we abstract b from g arriving at "let x = b in h x",
  3221 otherwise we unfold the let and arrive at g.  The simproc can be
  3222 enabled/disabled by the reference use_let_simproc.  Potential
  3223 INCOMPATIBILITY since simplification is more powerful by default.
  3224 
  3225 * Classical reasoning: the meson method now accepts theorems as arguments.
  3226 
  3227 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3228 jobs to provide advice on the provability of subgoals.
  3229 
  3230 * Theory OrderedGroup and Ring_and_Field: various additions and
  3231 improvements to faciliate calculations involving equalities and
  3232 inequalities.
  3233 
  3234 The following theorems have been eliminated or modified
  3235 (INCOMPATIBILITY):
  3236 
  3237   abs_eq             now named abs_of_nonneg
  3238   abs_of_ge_0        now named abs_of_nonneg
  3239   abs_minus_eq       now named abs_of_nonpos
  3240   imp_abs_id         now named abs_of_nonneg
  3241   imp_abs_neg_id     now named abs_of_nonpos
  3242   mult_pos           now named mult_pos_pos
  3243   mult_pos_le        now named mult_nonneg_nonneg
  3244   mult_pos_neg_le    now named mult_nonneg_nonpos
  3245   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3246   mult_neg           now named mult_neg_neg
  3247   mult_neg_le        now named mult_nonpos_nonpos
  3248 
  3249 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3250      
  3251      zero_le_square
  3252      not_square_less_zero 
  3253 
  3254   The following lemmas have been deleted from Real/RealPow:
  3255   
  3256      realpow_zero_zero
  3257      realpow_two
  3258      realpow_less
  3259      zero_le_power
  3260      realpow_two_le
  3261      abs_realpow_two
  3262      realpow_two_abs     
  3263 
  3264 * Theory Parity: added rules for simplifying exponents.
  3265 
  3266 * Theory List:
  3267 
  3268 The following theorems have been eliminated or modified
  3269 (INCOMPATIBILITY):
  3270 
  3271   list_all_Nil       now named list_all.simps(1)
  3272   list_all_Cons      now named list_all.simps(2)
  3273   list_all_conv      now named list_all_iff
  3274   set_mem_eq         now named mem_iff
  3275 
  3276 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3277 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3278 
  3279 
  3280 *** HOL-Complex ***
  3281 
  3282 * Theory RealDef: better support for embedding natural numbers and
  3283 integers in the reals.
  3284 
  3285 The following theorems have been eliminated or modified
  3286 (INCOMPATIBILITY):
  3287 
  3288   exp_ge_add_one_self  now requires no hypotheses
  3289   real_of_int_add      reversed direction of equality (use [symmetric])
  3290   real_of_int_minus    reversed direction of equality (use [symmetric])
  3291   real_of_int_diff     reversed direction of equality (use [symmetric])
  3292   real_of_int_mult     reversed direction of equality (use [symmetric])
  3293 
  3294 * Theory RComplete: expanded support for floor and ceiling functions.
  3295 
  3296 * Theory Ln is new, with properties of the natural logarithm
  3297 
  3298 * Hyperreal: There is a new type constructor "star" for making
  3299 nonstandard types.  The old type names are now type synonyms:
  3300 
  3301   hypreal = real star
  3302   hypnat = nat star
  3303   hcomplex = complex star
  3304 
  3305 * Hyperreal: Many groups of similarly-defined constants have been
  3306 replaced by polymorphic versions (INCOMPATIBILITY):
  3307 
  3308   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3309 
  3310   starset      <-- starsetNat, starsetC
  3311   *s*          <-- *sNat*, *sc*
  3312   starset_n    <-- starsetNat_n, starsetC_n
  3313   *sn*         <-- *sNatn*, *scn*
  3314   InternalSets <-- InternalNatSets, InternalCSets
  3315 
  3316   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3317   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3318   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3319   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3320   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3321 
  3322 * Hyperreal: Many type-specific theorems have been removed in favor of
  3323 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3324 
  3325   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3326   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3327   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3328   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3329   right_minus <-- hypreal_add_minus
  3330   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3331   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3332   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3333   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3334   mult_1_right <-- hcomplex_mult_one_right
  3335   mult_zero_left <-- hcomplex_mult_zero_left
  3336   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3337   right_distrib <-- hypnat_add_mult_distrib2
  3338   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3339   right_inverse <-- hypreal_mult_inverse
  3340   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3341   order_refl <-- {hypreal,hypnat}_le_refl
  3342   order_trans <-- {hypreal,hypnat}_le_trans
  3343   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3344   order_less_le <-- {hypreal,hypnat}_less_le
  3345   linorder_linear <-- {hypreal,hypnat}_le_linear
  3346   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3347   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3348   add_nonneg_nonneg <-- hypreal_le_add_order
  3349 
  3350 * Hyperreal: Separate theorems having to do with type-specific
  3351 versions of constants have been merged into theorems that apply to the
  3352 new polymorphic constants (INCOMPATIBILITY):
  3353 
  3354   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3355   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3356   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3357   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3358   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3359   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3360   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3361   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3362   STAR_diff <-- {STAR,STARC}_diff
  3363   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3364     STARC_hcomplex_of_complex}_image_subset
  3365   starset_n_Un <-- starset{Nat,C}_n_Un
  3366   starset_n_Int <-- starset{Nat,C}_n_Int
  3367   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3368   starset_n_diff <-- starset{Nat,C}_n_diff
  3369   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3370   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3371   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3372   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3373   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3374   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3375   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3376   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3377   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3378   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3379   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3380   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3381   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3382   starfun_diff <-- starfun{C,RC,CR}_diff
  3383   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3384   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3385   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3386   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3387   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3388   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3389   starfun_Id <-- starfunC_Id
  3390   starfun_approx <-- starfun{Nat,CR}_approx
  3391   starfun_capprox <-- starfun{C,RC}_capprox
  3392   starfun_abs <-- starfunNat_rabs
  3393   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3394   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3395   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3396   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3397   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3398   starfun_add_approx <-- starfunCR_add_approx
  3399   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3400   starfun_divide <-- starfun{C,CR,RC}_divide
  3401   starfun_n <-- starfun{Nat,C}_n
  3402   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3403   starfun_n_add <-- starfun{Nat,C}_n_add
  3404   starfun_n_add_minus <-- starfunNat_n_add_minus
  3405   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3406   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3407   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3408 
  3409   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3410   star_n_minus <-- {hypreal,hcomplex}_minus
  3411   star_n_diff <-- {hypreal,hcomplex}_diff
  3412   star_n_mult <-- {hypreal,hcomplex}_mult
  3413   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3414   star_n_le <-- {hypreal,hypnat}_le
  3415   star_n_less <-- {hypreal,hypnat}_less
  3416   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3417   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3418   star_n_abs <-- hypreal_hrabs
  3419   star_n_divide <-- hcomplex_divide
  3420 
  3421   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3422   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3423   star_of_diff <-- hypreal_of_real_diff
  3424   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3425   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3426   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3427   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3428   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3429   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3430   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3431   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3432   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3433   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3434   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3435   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3436   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3437   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3438   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3439   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3440   star_of_power <-- hypreal_of_real_power
  3441   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3442 
  3443 * Hyperreal: new method "transfer" that implements the transfer
  3444 principle of nonstandard analysis. With a subgoal that mentions
  3445 nonstandard types like "'a star", the command "apply transfer"
  3446 replaces it with an equivalent one that mentions only standard types.
  3447 To be successful, all free variables must have standard types; non-
  3448 standard variables must have explicit universal quantifiers.
  3449 
  3450 * Hyperreal: A theory of Taylor series.
  3451 
  3452 
  3453 *** HOLCF ***
  3454 
  3455 * Discontinued special version of 'constdefs' (which used to support
  3456 continuous functions) in favor of the general Pure one with full
  3457 type-inference.
  3458 
  3459 * New simplification procedure for solving continuity conditions; it
  3460 is much faster on terms with many nested lambda abstractions (cubic
  3461 instead of exponential time).
  3462 
  3463 * New syntax for domain package: selector names are now optional.
  3464 Parentheses should be omitted unless argument is lazy, for example:
  3465 
  3466   domain 'a stream = cons "'a" (lazy "'a stream")
  3467 
  3468 * New command 'fixrec' for defining recursive functions with pattern
  3469 matching; defining multiple functions with mutual recursion is also
  3470 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3471 sinr, or any data constructor defined by the domain package. The given
  3472 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3473 syntax and examples.
  3474 
  3475 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3476 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3477 but the proof obligation additionally includes an admissibility
  3478 requirement. The packages generate instances of class cpo or pcpo,
  3479 with continuity and strictness theorems for Rep and Abs.
  3480 
  3481 * HOLCF: Many theorems have been renamed according to a more standard naming
  3482 scheme (INCOMPATIBILITY):
  3483 
  3484   foo_inject:  "foo$x = foo$y ==> x = y"
  3485   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3486   foo_less:    "(foo$x << foo$y) = (x << y)"
  3487   foo_strict:  "foo$UU = UU"
  3488   foo_defined: "... ==> foo$x ~= UU"
  3489   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3490 
  3491 
  3492 *** ZF ***
  3493 
  3494 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3495 including the First Isomorphism Theorem (on quotienting by the kernel
  3496 of a homomorphism).
  3497 
  3498 * ZF/Simplifier: install second copy of type solver that actually
  3499 makes use of TC rules declared to Isar proof contexts (or locales);
  3500 the old version is still required for ML proof scripts.
  3501 
  3502 
  3503 *** Cube ***
  3504 
  3505 * Converted to Isar theory format; use locales instead of axiomatic
  3506 theories.
  3507 
  3508 
  3509 *** ML ***
  3510 
  3511 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3512 for ||>, ||>>, |>>,
  3513 
  3514 * Pure/library.ML no longer defines its own option datatype, but uses
  3515 that of the SML basis, which has constructors NONE and SOME instead of
  3516 None and Some, as well as exception Option.Option instead of OPTION.
  3517 The functions the, if_none, is_some, is_none have been adapted
  3518 accordingly, while Option.map replaces apsome.
  3519 
  3520 * Pure/library.ML: the exception LIST has been given up in favour of
  3521 the standard exceptions Empty and Subscript, as well as
  3522 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3523 superceded by the standard hd and tl functions etc.
  3524 
  3525 A number of basic list functions are no longer exported to the ML
  3526 toplevel, as they are variants of predefined functions.  The following
  3527 suggests how one can translate existing code:
  3528 
  3529     rev_append xs ys = List.revAppend (xs, ys)
  3530     nth_elem (i, xs) = List.nth (xs, i)
  3531     last_elem xs = List.last xs
  3532     flat xss = List.concat xss
  3533     seq fs = List.app fs
  3534     partition P xs = List.partition P xs
  3535     mapfilter f xs = List.mapPartial f xs
  3536 
  3537 * Pure/library.ML: several combinators for linear functional
  3538 transformations, notably reverse application and composition:
  3539 
  3540   x |> f                f #> g
  3541   (x, y) |-> f          f #-> g
  3542 
  3543 * Pure/library.ML: introduced/changed precedence of infix operators:
  3544 
  3545   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3546   infix 2 ?;
  3547   infix 3 o oo ooo oooo;
  3548   infix 4 ~~ upto downto;
  3549 
  3550 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3551 infix operators.
  3552 
  3553 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3554 fold_map support linear functional transformations and nesting.  For
  3555 example:
  3556 
  3557   fold f [x1, ..., xN] y =
  3558     y |> f x1 |> ... |> f xN
  3559 
  3560   (fold o fold) f [xs1, ..., xsN] y =
  3561     y |> fold f xs1 |> ... |> fold f xsN
  3562 
  3563   fold f [x1, ..., xN] =
  3564     f x1 #> ... #> f xN
  3565 
  3566   (fold o fold) f [xs1, ..., xsN] =
  3567     fold f xs1 #> ... #> fold f xsN
  3568 
  3569 * Pure/library.ML: the following selectors on type 'a option are
  3570 available:
  3571 
  3572   the:               'a option -> 'a  (*partial*)
  3573   these:             'a option -> 'a  where 'a = 'b list
  3574   the_default: 'a -> 'a option -> 'a
  3575   the_list:          'a option -> 'a list
  3576 
  3577 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3578 basic operations for association lists, following natural argument
  3579 order; moreover the explicit equality predicate passed here avoids
  3580 potentially expensive polymorphic runtime equality checks.
  3581 The old functions may be expressed as follows:
  3582 
  3583   assoc = uncurry (AList.lookup (op =))
  3584   assocs = these oo AList.lookup (op =)
  3585   overwrite = uncurry (AList.update (op =)) o swap
  3586 
  3587 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3588 
  3589   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3590   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3591 
  3592 replacing make_keylist and keyfilter (occassionally used)
  3593 Naive rewrites:
  3594 
  3595   make_keylist = AList.make
  3596   keyfilter = AList.find (op =)
  3597 
  3598 * eq_fst and eq_snd now take explicit equality parameter, thus
  3599   avoiding eqtypes. Naive rewrites:
  3600 
  3601     eq_fst = eq_fst (op =)
  3602     eq_snd = eq_snd (op =)
  3603 
  3604 * Removed deprecated apl and apr (rarely used).
  3605   Naive rewrites:
  3606 
  3607     apl (n, op) =>>= curry op n
  3608     apr (op, m) =>>= fn n => op (n, m)
  3609 
  3610 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3611 provides a reasonably efficient light-weight implementation of sets as
  3612 lists.
  3613 
  3614 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3615 few new operations; existing lookup and update are now curried to
  3616 follow natural argument order (for use with fold etc.);
  3617 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3618 
  3619 * Pure/General: output via the Isabelle channels of
  3620 writeln/warning/error etc. is now passed through Output.output, with a
  3621 hook for arbitrary transformations depending on the print_mode
  3622 (cf. Output.add_mode -- the first active mode that provides a output
  3623 function wins).  Already formatted output may be embedded into further
  3624 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3625 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3626 accommodate easy composition of diagnostic messages etc.  Programmers
  3627 rarely need to care about Output.output or Output.raw at all, with
  3628 some notable exceptions: Output.output is required when bypassing the
  3629 standard channels (writeln etc.), or in token translations to produce
  3630 properly formatted results; Output.raw is required when capturing
  3631 already output material that will eventually be presented to the user
  3632 a second time.  For the default print mode, both Output.output and
  3633 Output.raw have no effect.
  3634 
  3635 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3636 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3637 cumulative results are displayed at the end of a batch session.
  3638 
  3639 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3640 replaced by File.platform_path and File.shell_path (with appropriate
  3641 hooks).  This provides a clean interface for unusual systems where the
  3642 internal and external process view of file names are different.
  3643 
  3644 * Pure: more efficient orders for basic syntactic entities: added
  3645 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3646 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3647 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3648 orders now -- potential INCOMPATIBILITY for code that depends on a
  3649 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3650 Library.sort_strings on result).
  3651 
  3652 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3653 fold_types traverse types/terms from left to right, observing natural
  3654 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3655 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3656 
  3657 * Pure: name spaces have been refined, with significant changes of the
  3658 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3659 to extern(_table).  The plain name entry path is superceded by a
  3660 general 'naming' context, which also includes the 'policy' to produce
  3661 a fully qualified name and external accesses of a fully qualified
  3662 name; NameSpace.extend is superceded by context dependent
  3663 Sign.declare_name.  Several theory and proof context operations modify
  3664 the naming context.  Especially note Theory.restore_naming and
  3665 ProofContext.restore_naming to get back to a sane state; note that
  3666 Theory.add_path is no longer sufficient to recover from
  3667 Theory.absolute_path in particular.
  3668 
  3669 * Pure: new flags short_names (default false) and unique_names
  3670 (default true) for controlling output of qualified names.  If
  3671 short_names is set, names are printed unqualified.  If unique_names is
  3672 reset, the name prefix is reduced to the minimum required to achieve
  3673 the original result when interning again, even if there is an overlap
  3674 with earlier declarations.
  3675 
  3676 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3677 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3678 (useful for printing error messages).  INCOMPATIBILITY.
  3679 
  3680 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3681 Theory.theory are now identified, referring to the universal
  3682 Context.theory (see Pure/context.ML).  Actual signature and theory
  3683 content is managed as theory data.  The old code and interfaces were
  3684 spread over many files and structures; the new arrangement introduces
  3685 considerable INCOMPATIBILITY to gain more clarity:
  3686 
  3687   Context -- theory management operations (name, identity, inclusion,
  3688     parents, ancestors, merge, etc.), plus generic theory data;
  3689 
  3690   Sign -- logical signature and syntax operations (declaring consts,
  3691     types, etc.), plus certify/read for common entities;
  3692 
  3693   Theory -- logical theory operations (stating axioms, definitions,
  3694     oracles), plus a copy of logical signature operations (consts,
  3695     types, etc.); also a few basic management operations (Theory.copy,
  3696     Theory.merge, etc.)
  3697 
  3698 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3699 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3700 for convenience -- they merely return the theory.
  3701 
  3702 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3703 
  3704 * Pure: the Isar proof context type is already defined early in Pure
  3705 as Context.proof (note that ProofContext.context and Proof.context are
  3706 aliases, where the latter is the preferred name).  This enables other
  3707 Isabelle components to refer to that type even before Isar is present.
  3708 
  3709 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3710 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3711 any of these kinds.  For example, Sign.intern typeK is now
  3712 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3713 Theory.hide_types.  Also note that former
  3714 Theory.hide_classes/types/consts are now
  3715 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3716 internalize their arguments!  INCOMPATIBILITY.
  3717 
  3718 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3719 datatype thmref (with constructors Name and NameSelection) instead of
  3720 plain string -- INCOMPATIBILITY;
  3721 
  3722 * Pure: cases produced by proof methods specify options, where NONE
  3723 means to remove case bindings -- INCOMPATIBILITY in
  3724 (RAW_)METHOD_CASES.
  3725 
  3726 * Pure: the following operations retrieve axioms or theorems from a
  3727 theory node or theory hierarchy, respectively:
  3728 
  3729   Theory.axioms_of: theory -> (string * term) list
  3730   Theory.all_axioms_of: theory -> (string * term) list
  3731   PureThy.thms_of: theory -> (string * thm) list
  3732   PureThy.all_thms_of: theory -> (string * thm) list
  3733 
  3734 * Pure: print_tac now outputs the goal through the trace channel.
  3735 
  3736 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3737 Reference Toplevel.debug (default false) controls detailed printing
  3738 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3739 controls execution profiling -- set to 1 for time and 2 for space
  3740 (both increase the runtime).
  3741 
  3742 * Isar session: The initial use of ROOT.ML is now always timed,
  3743 i.e. the log will show the actual process times, in contrast to the
  3744 elapsed wall-clock time that the outer shell wrapper produces.
  3745 
  3746 * Simplifier: improved handling of bound variables (nameless
  3747 representation, avoid allocating new strings).  Simprocs that invoke
  3748 the Simplifier recursively should use Simplifier.inherit_bounds to
  3749 avoid local name clashes.  Failure to do so produces warnings
  3750 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3751 for further details.
  3752 
  3753 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3754 bindings for all theorems stored within a given theory; this may help
  3755 in porting non-Isar theories to Isar ones, while keeping ML proof
  3756 scripts for the time being.
  3757 
  3758 * ML operator HTML.with_charset specifies the charset begin used for
  3759 generated HTML files.  For example:
  3760 
  3761   HTML.with_charset "utf-8" use_thy "Hebrew";
  3762   HTML.with_charset "utf-8" use_thy "Chinese";
  3763 
  3764 
  3765 *** System ***
  3766 
  3767 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3768 isabelle, isatool etc.).
  3769 
  3770 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3771 isatool doc, isatool mkdir, display_drafts etc.).
  3772 
  3773 * isatool usedir: option -f allows specification of the ML file to be
  3774 used by Isabelle; default is ROOT.ML.
  3775 
  3776 * New isatool version outputs the version identifier of the Isabelle
  3777 distribution being used.
  3778 
  3779 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3780 (containing Boolean satisfiability problems) into Isabelle/HOL
  3781 theories.
  3782 
  3783 
  3784 
  3785 New in Isabelle2004 (April 2004)
  3786 --------------------------------
  3787 
  3788 *** General ***
  3789 
  3790 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3791   Replaces linorder.ML.
  3792 
  3793 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3794   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3795   (\<a>...\<z>), are now considered normal letters, and can therefore
  3796   be used anywhere where an ASCII letter (a...zA...Z) has until
  3797   now. COMPATIBILITY: This obviously changes the parsing of some
  3798   terms, especially where a symbol has been used as a binder, say
  3799   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3800   as an identifier.  Fix it by inserting a space around former
  3801   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3802   existing theory and ML files.
  3803 
  3804 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3805 
  3806 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3807   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3808   a normal (but invisible) letter. For multiple letter subscripts repeat
  3809   \<^isub> like this: x\<^isub>1\<^isub>2.
  3810 
  3811 * Pure: There are now sub-/superscripts that can span more than one
  3812   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3813   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3814   superscript. The new control characters are not identifier parts.
  3815 
  3816 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3817   content of "..." to the latex file instead of \isacntrl... . The "..."
  3818   may consist of any printable characters excluding the end bracket >.
  3819 
  3820 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3821   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3822   declare constants "final", which prevents their being given a definition
  3823   later.  It is useful for constants whose behaviour is fixed axiomatically
  3824   rather than definitionally, such as the meta-logic connectives.
  3825 
  3826 * Pure: 'instance' now handles general arities with general sorts
  3827   (i.e. intersections of classes),
  3828 
  3829 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3830   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3831   It can be changed to alter the colors/layout of generated pages.
  3832 
  3833 
  3834 *** Isar ***
  3835 
  3836 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3837   cut_tac, subgoal_tac and thin_tac:
  3838   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3839     locales are no longer forced to write Isar proof scripts.
  3840     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3841     emulations.
  3842   - INCOMPATIBILITY: names of variables to be instantiated may no
  3843     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3844     This is consistent with the instantiation attribute "where".
  3845 
  3846 * Attributes "where" and "of":
  3847   - Now take type variables of instantiated theorem into account when reading
  3848     the instantiation string.  This fixes a bug that caused instantiated
  3849     theorems to have too special types in some circumstances.
  3850   - "where" permits explicit instantiations of type variables.
  3851 
  3852 * Calculation commands "moreover" and "also" no longer interfere with
  3853   current facts ("this"), admitting arbitrary combinations with "then"
  3854   and derived forms.
  3855 
  3856 * Locales:
  3857   - Goal statements involving the context element "includes" no longer
  3858     generate theorems with internal delta predicates (those ending on
  3859     "_axioms") in the premise.
  3860     Resolve particular premise with <locale>.intro to obtain old form.
  3861   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3862     specification and "includes" elements in goal statement.
  3863   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3864     [intro?] and [elim?] (respectively) by default.
  3865   - Experimental command for instantiation of locales in proof contexts:
  3866         instantiate <label>[<attrs>]: <loc>
  3867     Instantiates locale <loc> and adds all its theorems to the current context
  3868     taking into account their attributes.  Label and attrs are optional
  3869     modifiers, like in theorem declarations.  If present, names of
  3870     instantiated theorems are qualified with <label>, and the attributes
  3871     <attrs> are applied after any attributes these theorems might have already.
  3872       If the locale has assumptions, a chained fact of the form
  3873     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3874     are derived.  The command does not support old-style locales declared
  3875     with "locale (open)".
  3876       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3877 
  3878 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3879   (Isar) contexts.
  3880 
  3881 
  3882 *** HOL ***
  3883 
  3884 * Proof import: new image HOL4 contains the imported library from
  3885   the HOL4 system with about 2500 theorems. It is imported by
  3886   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3887   can be used like any other Isabelle image.  See
  3888   HOL/Import/HOL/README for more information.
  3889 
  3890 * Simplifier:
  3891   - Much improved handling of linear and partial orders.
  3892     Reasoners for linear and partial orders are set up for type classes
  3893     "linorder" and "order" respectively, and are added to the default simpset
  3894     as solvers.  This means that the simplifier can build transitivity chains
  3895     to solve goals from the assumptions.
  3896   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3897     of blast or auto after simplification become unnecessary because the goal
  3898     is solved by simplification already.
  3899 
  3900 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3901     all proved in axiomatic type classes for semirings, rings and fields.
  3902 
  3903 * Numerics:
  3904   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3905     now formalized using the Ring_and_Field theory mentioned above.
  3906   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3907     than before, because now they are set up once in a generic manner.
  3908   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3909     Look for the general versions in Ring_and_Field (and Power if they concern
  3910     exponentiation).
  3911 
  3912 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3913 
  3914 * Records:
  3915   - Record types are now by default printed with their type abbreviation
  3916     instead of the list of all field types. This can be configured via
  3917     the reference "print_record_type_abbr".
  3918   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3919     (not enabled by default).
  3920   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3921     EX x. x = sel r to True (not enabled by default).
  3922   - Tactic "record_split_simp_tac" to split and simplify records added.
  3923 
  3924 * 'specification' command added, allowing for definition by
  3925   specification.  There is also an 'ax_specification' command that
  3926   introduces the new constants axiomatically.
  3927 
  3928 * arith(_tac) is now able to generate counterexamples for reals as well.
  3929 
  3930 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3931 
  3932 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3933   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3934 
  3935 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3936   matrix theory to linear programming.
  3937 
  3938 * Unions and Intersections:
  3939   The latex output syntax of UN and INT has been changed
  3940   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3941   i.e. the index formulae has become a subscript.
  3942   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3943 
  3944 * Unions and Intersections over Intervals:
  3945   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3946   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3947   like in normal math, and corresponding versions for < and for intersection.
  3948 
  3949 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3950   lexicographic dictonary ordering has been added as "lexord".
  3951 
  3952 * ML: the legacy theory structures Int and List have been removed. They had
  3953   conflicted with ML Basis Library structures having the same names.
  3954 
  3955 * 'refute' command added to search for (finite) countermodels.  Only works
  3956   for a fragment of HOL.  The installation of an external SAT solver is
  3957   highly recommended.  See "HOL/Refute.thy" for details.
  3958 
  3959 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3960   formulae under an assignment of free variables to random values.
  3961   In contrast to 'refute', it can deal with inductive datatypes,
  3962   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3963   for examples.
  3964 
  3965 
  3966 *** HOLCF ***
  3967 
  3968 * Streams now come with concatenation and are part of the HOLCF image
  3969 
  3970 
  3971 
  3972 New in Isabelle2003 (May 2003)
  3973 ------------------------------
  3974 
  3975 *** General ***
  3976 
  3977 * Provers/simplifier:
  3978 
  3979   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3980     Assumptions are now subject to complete mutual simplification,
  3981     not just from left to right. The simplifier now preserves
  3982     the order of assumptions.
  3983 
  3984     Potential INCOMPATIBILITY:
  3985 
  3986     -- simp sometimes diverges where the old version did
  3987        not, e.g. invoking simp on the goal
  3988 
  3989         [| P (f x); y = x; f x = f y |] ==> Q
  3990 
  3991        now gives rise to the infinite reduction sequence
  3992 
  3993         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3994 
  3995        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3996        kind of problem.
  3997 
  3998     -- Tactics combining classical reasoner and simplification (such as auto)
  3999        are also affected by this change, because many of them rely on
  4000        simp. They may sometimes diverge as well or yield a different numbers
  4001        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4002        in case of problems. Sometimes subsequent calls to the classical
  4003        reasoner will fail because a preceeding call to the simplifier too
  4004        eagerly simplified the goal, e.g. deleted redundant premises.
  4005 
  4006   - The simplifier trace now shows the names of the applied rewrite rules
  4007 
  4008   - You can limit the number of recursive invocations of the simplifier
  4009     during conditional rewriting (where the simplifie tries to solve the
  4010     conditions before applying the rewrite rule):
  4011     ML "simp_depth_limit := n"
  4012     where n is an integer. Thus you can force termination where previously
  4013     the simplifier would diverge.
  4014 
  4015   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4016 
  4017   - No longer aborts on failed congruence proof.  Instead, the
  4018     congruence is ignored.
  4019 
  4020 * Pure: New generic framework for extracting programs from constructive
  4021   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4022   as HOL/Extraction for some case studies.
  4023 
  4024 * Pure: The main goal of the proof state is no longer shown by default, only
  4025 the subgoals. This behaviour is controlled by a new flag.
  4026    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4027 (ML: Proof.show_main_goal).
  4028 
  4029 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4030 rules whose conclusion matches subgoal 1:
  4031       PG menu: Isabelle/Isar -> Show me -> matching rules
  4032 The rules are ordered by how closely they match the subgoal.
  4033 In particular, rules that solve a subgoal outright are displayed first
  4034 (or rather last, the way they are printed).
  4035 (ML: ProofGeneral.print_intros())
  4036 
  4037 * Pure: New flag trace_unify_fail causes unification to print
  4038 diagnostic information (PG: in trace buffer) when it fails. This is
  4039 useful for figuring out why single step proofs like rule, erule or
  4040 assumption failed.
  4041 
  4042 * Pure: Locale specifications now produce predicate definitions
  4043 according to the body of text (covering assumptions modulo local
  4044 definitions); predicate "loc_axioms" covers newly introduced text,
  4045 while "loc" is cumulative wrt. all included locale expressions; the
  4046 latter view is presented only on export into the global theory
  4047 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4048 on the old view without predicates;
  4049 
  4050 * Pure: predefined locales "var" and "struct" are useful for sharing
  4051 parameters (as in CASL, for example); just specify something like
  4052 ``var x + var y + struct M'' as import;
  4053 
  4054 * Pure: improved thms_containing: proper indexing of facts instead of
  4055 raw theorems; check validity of results wrt. current name space;
  4056 include local facts of proof configuration (also covers active
  4057 locales), cover fixed variables in index; may use "_" in term
  4058 specification; an optional limit for the number of printed facts may
  4059 be given (the default is 40);
  4060 
  4061 * Pure: disallow duplicate fact bindings within new-style theory files
  4062 (batch-mode only);
  4063 
  4064 * Provers: improved induct method: assumptions introduced by case
  4065 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4066 the goal statement); "foo" still refers to all facts collectively;
  4067 
  4068 * Provers: the function blast.overloaded has been removed: all constants
  4069 are regarded as potentially overloaded, which improves robustness in exchange
  4070 for slight decrease in efficiency;
  4071 
  4072 * Provers/linorder: New generic prover for transitivity reasoning over
  4073 linear orders.  Note: this prover is not efficient!
  4074 
  4075 * Isar: preview of problems to finish 'show' now produce an error
  4076 rather than just a warning (in interactive mode);
  4077 
  4078 
  4079 *** HOL ***
  4080 
  4081 * arith(_tac)
  4082 
  4083  - Produces a counter example if it cannot prove a goal.
  4084    Note that the counter example may be spurious if the goal is not a formula
  4085    of quantifier-free linear arithmetic.
  4086    In ProofGeneral the counter example appears in the trace buffer.
  4087 
  4088  - Knows about div k and mod k where k is a numeral of type nat or int.
  4089 
  4090  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4091    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4092    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4093 
  4094 * simp's arithmetic capabilities have been enhanced a bit: it now
  4095 takes ~= in premises into account (by performing a case split);
  4096 
  4097 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4098 are distributed over a sum of terms;
  4099 
  4100 * New tactic "trans_tac" and method "trans" instantiate
  4101 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4102 "<=", "<" and "=").
  4103 
  4104 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4105 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4106 
  4107 * 'typedef' command has new option "open" to suppress the set
  4108 definition;
  4109 
  4110 * functions Min and Max on finite sets have been introduced (theory
  4111 Finite_Set);
  4112 
  4113 * attribute [symmetric] now works for relations as well; it turns
  4114 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4115 
  4116 * induct over a !!-quantified statement (say !!x1..xn):
  4117   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4118 
  4119 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4120 %x. None. Warning: empty_def now refers to the previously hidden definition
  4121 of the empty set.
  4122 
  4123 * Algebra: formalization of classical algebra.  Intended as base for
  4124 any algebraic development in Isabelle.  Currently covers group theory
  4125 (up to Sylow's theorem) and ring theory (Universal Property of
  4126 Univariate Polynomials).  Contributions welcome;
  4127 
  4128 * GroupTheory: deleted, since its material has been moved to Algebra;
  4129 
  4130 * Complex: new directory of the complex numbers with numeric constants,
  4131 nonstandard complex numbers, and some complex analysis, standard and
  4132 nonstandard (Jacques Fleuriot);
  4133 
  4134 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4135 
  4136 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4137 Fleuriot);
  4138 
  4139 * Real/HahnBanach: updated and adapted to locales;
  4140 
  4141 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4142 Gray and Kramer);
  4143 
  4144 * UNITY: added the Meier-Sanders theory of progress sets;
  4145 
  4146 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4147 as abstract algorithms, instantiated to the JVM;
  4148 
  4149 * Bali: Java source language formalization. Type system, operational
  4150 semantics, axiomatic semantics. Supported language features:
  4151 classes, interfaces, objects,virtual methods, static methods,
  4152 static/instance fields, arrays, access modifiers, definite
  4153 assignment, exceptions.
  4154 
  4155 
  4156 *** ZF ***
  4157 
  4158 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4159 universe, etc.);
  4160 
  4161 * Main ZF: virtually all theories converted to new-style format;
  4162 
  4163 
  4164 *** ML ***
  4165 
  4166 * Pure: Tactic.prove provides sane interface for internal proofs;
  4167 omits the infamous "standard" operation, so this is more appropriate
  4168 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4169 
  4170 * Pure: improved error reporting of simprocs;
  4171 
  4172 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4173 up simprocs;
  4174 
  4175 
  4176 *** Document preparation ***
  4177 
  4178 * uses \par instead of \\ for line breaks in theory text. This may
  4179 shift some page breaks in large documents. To get the old behaviour
  4180 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4181 
  4182 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4183 other packages
  4184 
  4185 * \<euro> now needs package babel/greek instead of marvosym (which
  4186 broke \Rightarrow)
  4187 
  4188 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4189 textcomp package)
  4190 
  4191 
  4192 
  4193 New in Isabelle2002 (March 2002)
  4194 --------------------------------
  4195 
  4196 *** Document preparation ***
  4197 
  4198 * greatly simplified document preparation setup, including more
  4199 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4200 instructive isatool mkdir; users should basically be able to get
  4201 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4202 users may run a separate document processing stage manually like this:
  4203 "isatool usedir -D output HOL Test && isatool document Test/output";
  4204 
  4205 * theory dependency graph may now be incorporated into documents;
  4206 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4207 with \includegraphics of LaTeX;
  4208 
  4209 * proper spacing of consecutive markup elements, especially text
  4210 blocks after section headings;
  4211 
  4212 * support bold style (for single symbols only), input syntax is like
  4213 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4214 
  4215 * \<bullet> is now output as bold \cdot by default, which looks much
  4216 better in printed text;
  4217 
  4218 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4219 note that these symbols are currently unavailable in Proof General /
  4220 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4221 
  4222 * isatool latex no longer depends on changed TEXINPUTS, instead
  4223 isatool document copies the Isabelle style files to the target
  4224 location;
  4225 
  4226 
  4227 *** Isar ***
  4228 
  4229 * Pure/Provers: improved proof by cases and induction;
  4230   - 'case' command admits impromptu naming of parameters (such as
  4231     "case (Suc n)");
  4232   - 'induct' method divinates rule instantiation from the inductive
  4233     claim; no longer requires excessive ?P bindings for proper
  4234     instantiation of cases;
  4235   - 'induct' method properly enumerates all possibilities of set/type
  4236     rules; as a consequence facts may be also passed through *type*
  4237     rules without further ado;
  4238   - 'induct' method now derives symbolic cases from the *rulified*
  4239     rule (before it used to rulify cases stemming from the internal
  4240     atomized version); this means that the context of a non-atomic
  4241     statement becomes is included in the hypothesis, avoiding the
  4242     slightly cumbersome show "PROP ?case" form;
  4243   - 'induct' may now use elim-style induction rules without chaining
  4244     facts, using ``missing'' premises from the goal state; this allows
  4245     rules stemming from inductive sets to be applied in unstructured
  4246     scripts, while still benefitting from proper handling of non-atomic
  4247     statements; NB: major inductive premises need to be put first, all
  4248     the rest of the goal is passed through the induction;
  4249   - 'induct' proper support for mutual induction involving non-atomic
  4250     rule statements (uses the new concept of simultaneous goals, see
  4251     below);
  4252   - append all possible rule selections, but only use the first
  4253     success (no backtracking);
  4254   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4255   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4256   - added 'print_induct_rules' (covered by help item in recent Proof
  4257     General versions);
  4258   - moved induct/cases attributes to Pure, methods to Provers;
  4259   - generic method setup instantiated for FOL and HOL;
  4260 
  4261 * Pure: support multiple simultaneous goal statements, for example
  4262 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4263 meta-level mechanism, this acts as if several individual goals had
  4264 been stated separately; in particular common proof methods need to be
  4265 repeated in order to cover all claims; note that a single elimination
  4266 step is *not* sufficient to establish the two conjunctions, so this
  4267 fails:
  4268 
  4269   assume "A & B" then have A and B ..   (*".." fails*)
  4270 
  4271 better use "obtain" in situations as above; alternative refer to
  4272 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4273 
  4274 * Pure: proper integration with ``locales''; unlike the original
  4275 version by Florian Kammller, Isar locales package high-level proof
  4276 contexts rather than raw logical ones (e.g. we admit to include
  4277 attributes everywhere); operations on locales include merge and
  4278 rename; support for implicit arguments (``structures''); simultaneous
  4279 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4280 some examples;
  4281 
  4282 * Pure: the following commands have been ``localized'', supporting a
  4283 target locale specification "(in name)": 'lemma', 'theorem',
  4284 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4285 stored both within the locale and at the theory level (exported and
  4286 qualified by the locale name);
  4287 
  4288 * Pure: theory goals may now be specified in ``long'' form, with
  4289 ad-hoc contexts consisting of arbitrary locale elements. for example
  4290 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4291 definitions may be given, too); the result is a meta-level rule with
  4292 the context elements being discharged in the obvious way;
  4293 
  4294 * Pure: new proof command 'using' allows to augment currently used
  4295 facts after a goal statement ('using' is syntactically analogous to
  4296 'apply', but acts on the goal's facts only); this allows chained facts
  4297 to be separated into parts given before and after a claim, as in
  4298 ``from a and b have C using d and e <proof>'';
  4299 
  4300 * Pure: renamed "antecedent" case to "rule_context";
  4301 
  4302 * Pure: new 'judgment' command records explicit information about the
  4303 object-logic embedding (used by several tools internally); no longer
  4304 use hard-wired "Trueprop";
  4305 
  4306 * Pure: added 'corollary' command;
  4307 
  4308 * Pure: fixed 'token_translation' command;
  4309 
  4310 * Pure: removed obsolete 'exported' attribute;
  4311 
  4312 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4313 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4314 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4315 
  4316 * Pure: method 'atomize' presents local goal premises as object-level
  4317 statements (atomic meta-level propositions); setup controlled via
  4318 rewrite rules declarations of 'atomize' attribute; example
  4319 application: 'induct' method with proper rule statements in improper
  4320 proof *scripts*;
  4321 
  4322 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4323 now consider the syntactic context of assumptions, giving a better
  4324 chance to get type-inference of the arguments right (this is
  4325 especially important for locales);
  4326 
  4327 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4328 mode;
  4329 
  4330 * Pure/obtain: the formal conclusion "thesis", being marked as
  4331 ``internal'', may no longer be reference directly in the text;
  4332 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4333 situations;
  4334 
  4335 * Pure: generic 'sym' attribute which declares a rule both as pure
  4336 'elim?' and for the 'symmetric' operation;
  4337 
  4338 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4339 text; the fixed correlation with particular command syntax has been
  4340 discontinued;
  4341 
  4342 * Pure: new method 'rules' is particularly well-suited for proof
  4343 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4344 but often produces more compact proof terms with less detours;
  4345 
  4346 * Pure/Provers/classical: simplified integration with pure rule
  4347 attributes and methods; the classical "intro?/elim?/dest?"
  4348 declarations coincide with the pure ones; the "rule" method no longer
  4349 includes classically swapped intros; "intro" and "elim" methods no
  4350 longer pick rules from the context; also got rid of ML declarations
  4351 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4352 INCOMPATIBILITY;
  4353 
  4354 * Provers/classical: attribute 'swapped' produces classical inversions
  4355 of introduction rules;
  4356 
  4357 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4358 rules instead of full simplifier context; 'iff' attribute handles
  4359 conditional rules;
  4360 
  4361 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4362 
  4363 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4364 "(permissive)" option to recover old behavior;
  4365 
  4366 * HOL: 'inductive' no longer features separate (collective) attributes
  4367 for 'intros' (was found too confusing);
  4368 
  4369 * HOL: properly declared induction rules less_induct and
  4370 wf_induct_rule;
  4371 
  4372 
  4373 *** HOL ***
  4374 
  4375 * HOL: moved over to sane numeral syntax; the new policy is as
  4376 follows:
  4377 
  4378   - 0 and 1 are polymorphic constants, which are defined on any
  4379   numeric type (nat, int, real etc.);
  4380 
  4381   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4382   binary representation internally;
  4383 
  4384   - type nat has special constructor Suc, and generally prefers Suc 0
  4385   over 1::nat and Suc (Suc 0) over 2::nat;
  4386 
  4387 This change may cause significant problems of INCOMPATIBILITY; here
  4388 are some hints on converting existing sources:
  4389 
  4390   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4391   entities, so expressions involving "-" (unary or binary minus) need
  4392   to be spaced properly;
  4393 
  4394   - existing occurrences of "1" may need to be constraint "1::nat" or
  4395   even replaced by Suc 0; similar for old "2";
  4396 
  4397   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4398 
  4399   - remove all special provisions on numerals in proofs;
  4400 
  4401 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4402 representation (depends on bin_arith_simps in the default context);
  4403 
  4404 * HOL: symbolic syntax for x^2 (numeral 2);
  4405 
  4406 * HOL: the class of all HOL types is now called "type" rather than
  4407 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4408 in axclass/classes, instance/arities, and (usually rare) occurrences
  4409 in typings (of consts etc.); internally the class is called
  4410 "HOL.type", ML programs should refer to HOLogic.typeS;
  4411 
  4412 * HOL/record package improvements:
  4413   - new derived operations "fields" to build a partial record section,
  4414     "extend" to promote a fixed record to a record scheme, and
  4415     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4416     declared as simp by default;
  4417   - shared operations ("more", "fields", etc.) now need to be always
  4418     qualified) --- potential INCOMPATIBILITY;
  4419   - removed "make_scheme" operations (use "make" with "extend") --
  4420     INCOMPATIBILITY;
  4421   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4422   - provides cases/induct rules for use with corresponding Isar
  4423     methods (for concrete records, record schemes, concrete more
  4424     parts, and schematic more parts -- in that order);
  4425   - internal definitions directly based on a light-weight abstract
  4426     theory of product types over typedef rather than datatype;
  4427 
  4428 * HOL: generic code generator for generating executable ML code from
  4429 specifications; specific support for HOL constructs such as inductive
  4430 datatypes and sets, as well as recursive functions; can be invoked
  4431 via 'generate_code' theory section;
  4432 
  4433 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4434 
  4435 * HOL: consolidated and renamed several theories.  In particular:
  4436         Ord.thy has been absorbed into HOL.thy
  4437         String.thy has been absorbed into List.thy
  4438 
  4439 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4440 (beware of argument permutation!);
  4441 
  4442 * HOL: linorder_less_split superseded by linorder_cases;
  4443 
  4444 * HOL/List: "nodups" renamed to "distinct";
  4445 
  4446 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4447 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4448   - Ex_def has changed, now need to use some_eq_ex
  4449 
  4450 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4451 in this (rare) case use:
  4452 
  4453   delSWrapper "split_all_tac"
  4454   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4455 
  4456 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4457 MAY FAIL;
  4458 
  4459 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4460 Isabelle's type classes, ^ on functions and relations has too general
  4461 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4462 necessary to attach explicit type constraints;
  4463 
  4464 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4465 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4466 renamed accordingly (eg "compI" -> "rel_compI").
  4467 
  4468 * HOL: syntax translations now work properly with numerals and records
  4469 expressions;
  4470 
  4471 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4472 of "lam" -- INCOMPATIBILITY;
  4473 
  4474 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4475 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4476 renamed "Product_Type.unit";
  4477 
  4478 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4479 
  4480 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4481 the "cases" method);
  4482 
  4483 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4484 Florian Kammller);
  4485 
  4486 * HOL/IMP: updated and converted to new-style theory format; several
  4487 parts turned into readable document, with proper Isar proof texts and
  4488 some explanations (by Gerwin Klein);
  4489 
  4490 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4491 
  4492 * HOL-Hyperreal is now a logic image;
  4493 
  4494 
  4495 *** HOLCF ***
  4496 
  4497 * Isar: consts/constdefs supports mixfix syntax for continuous
  4498 operations;
  4499 
  4500 * Isar: domain package adapted to new-style theory format, e.g. see
  4501 HOLCF/ex/Dnat.thy;
  4502 
  4503 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4504 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4505 lift.induct_tac, always use UU instead of Undef;
  4506 
  4507 * HOLCF/IMP: updated and converted to new-style theory;
  4508 
  4509 
  4510 *** ZF ***
  4511 
  4512 * Isar: proper integration of logic-specific tools and packages,
  4513 including theory commands '(co)inductive', '(co)datatype',
  4514 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4515 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4516 
  4517 * theory Main no longer includes AC; for the Axiom of Choice, base
  4518 your theory on Main_ZFC;
  4519 
  4520 * the integer library now covers quotients and remainders, with many
  4521 laws relating division to addition, multiplication, etc.;
  4522 
  4523 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4524 typeless version of the formalism;
  4525 
  4526 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4527 format;
  4528 
  4529 * ZF/Induct: new directory for examples of inductive definitions,
  4530 including theory Multiset for multiset orderings; converted to
  4531 new-style theory format;
  4532 
  4533 * ZF: many new theorems about lists, ordinals, etc.;
  4534 
  4535 
  4536 *** General ***
  4537 
  4538 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4539 variable proof controls level of detail: 0 = no proofs (only oracle
  4540 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4541 also ref manual for further ML interfaces;
  4542 
  4543 * Pure/axclass: removed obsolete ML interface
  4544 goal_subclass/goal_arity;
  4545 
  4546 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4547 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4548 separate tokens, so expressions involving minus need to be spaced
  4549 properly;
  4550 
  4551 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4552 rather than "infixl" or "infixr";
  4553 
  4554 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4555 sort constraint specifications in type inference; e.g. "x::_::foo"
  4556 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4557 type variable);
  4558 
  4559 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4560 control output of nested => (types); the default behavior is
  4561 "type_brackets";
  4562 
  4563 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4564 tokens into AST constants;
  4565 
  4566 * Pure/syntax: prefer later declarations of translations and print
  4567 translation functions; potential INCOMPATIBILITY: need to reverse
  4568 multiple declarations for same syntax element constant;
  4569 
  4570 * Pure/show_hyps reset by default (in accordance to existing Isar
  4571 practice);
  4572 
  4573 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4574 addSafter;
  4575 
  4576 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4577 as well;
  4578 
  4579 * system: tested support for MacOS X; should be able to get Isabelle +
  4580 Proof General to work in a plain Terminal after installing Poly/ML
  4581 (e.g. from the Isabelle distribution area) and GNU bash alone
  4582 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4583 support requires further installations, e.g. from
  4584 http://fink.sourceforge.net/);
  4585 
  4586 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4587 
  4588 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4589 of 40 MB), cf. ML_OPTIONS;
  4590 
  4591 * system: Proof General keywords specification is now part of the
  4592 Isabelle distribution (see etc/isar-keywords.el);
  4593 
  4594 * system: support for persistent Proof General sessions (refrain from
  4595 outdating all loaded theories on startup); user may create writable
  4596 logic images like this: ``isabelle -q HOL Test'';
  4597 
  4598 * system: smart selection of Isabelle process versus Isabelle
  4599 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4600 run both "isabelle" and "Isabelle" even if file names are badly
  4601 damaged (executable inspects the case of the first letter of its own
  4602 name); added separate "isabelle-process" and "isabelle-interface";
  4603 
  4604 * system: refrain from any attempt at filtering input streams; no
  4605 longer support ``8bit'' encoding of old isabelle font, instead proper
  4606 iso-latin characters may now be used; the related isatools
  4607 "symbolinput" and "nonascii" have disappeared as well;
  4608 
  4609 * system: removed old "xterm" interface (the print modes "xterm" and
  4610 "xterm_color" are still available for direct use in a suitable
  4611 terminal);
  4612 
  4613 
  4614 
  4615 New in Isabelle99-2 (February 2001)
  4616 -----------------------------------
  4617 
  4618 *** Overview of INCOMPATIBILITIES ***
  4619 
  4620 * HOL: please note that theories in the Library and elsewhere often use the
  4621 new-style (Isar) format; to refer to their theorems in an ML script you must
  4622 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4623 
  4624 * HOL: inductive package no longer splits induction rule aggressively,
  4625 but only as far as specified by the introductions given; the old
  4626 format may be recovered via ML function complete_split_rule or attribute
  4627 'split_rule (complete)';
  4628 
  4629 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4630 gfp_Tarski to gfp_unfold;
  4631 
  4632 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4633 
  4634 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4635 relation); infix "^^" has been renamed "``"; infix "``" has been
  4636 renamed "`"; "univalent" has been renamed "single_valued";
  4637 
  4638 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4639 operation;
  4640 
  4641 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4642 
  4643 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4644 
  4645 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4646 consequence, it is no longer monotonic wrt. the local goal context
  4647 (which is now passed through the inductive cases);
  4648 
  4649 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4650 \<gg> to \<ggreater>;
  4651 
  4652 
  4653 *** Document preparation ***
  4654 
  4655 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4656 available: are "it" for near math-mode best-style output, "sl" for
  4657 slanted text style, and "tt" for plain type-writer; if no
  4658 \isabellestyle command is given, output is according to slanted
  4659 type-writer);
  4660 
  4661 * support sub/super scripts (for single symbols only), input syntax is
  4662 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4663 
  4664 * some more standard symbols; see Appendix A of the system manual for
  4665 the complete list of symbols defined in isabellesym.sty;
  4666 
  4667 * improved isabelle style files; more abstract symbol implementation
  4668 (should now use \isamath{...} and \isatext{...} in custom symbol
  4669 definitions);
  4670 
  4671 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4672 state; Note that presentation of goal states does not conform to
  4673 actual human-readable proof documents.  Please do not include goal
  4674 states into document output unless you really know what you are doing!
  4675 
  4676 * proper indentation of antiquoted output with proportional LaTeX
  4677 fonts;
  4678 
  4679 * no_document ML operator temporarily disables LaTeX document
  4680 generation;
  4681 
  4682 * isatool unsymbolize tunes sources for plain ASCII communication;
  4683 
  4684 
  4685 *** Isar ***
  4686 
  4687 * Pure: Isar now suffers initial goal statements to contain unbound
  4688 schematic variables (this does not conform to actual readable proof
  4689 documents, due to unpredictable outcome and non-compositional proof
  4690 checking); users who know what they are doing may use schematic goals
  4691 for Prolog-style synthesis of proven results;
  4692 
  4693 * Pure: assumption method (an implicit finishing) now handles actual
  4694 rules as well;
  4695 
  4696 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4697 initial goal, declare "that" only as Pure intro (only for single
  4698 steps); the "that" rule assumption may now be involved in implicit
  4699 finishing, thus ".." becomes a feasible for trivial obtains;
  4700 
  4701 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4702 instance proofs may be performed by "..";
  4703 
  4704 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4705 statements as well;
  4706 
  4707 * Pure: more robust selection of calculational rules;
  4708 
  4709 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4710 rule (as well as the assumption rule);
  4711 
  4712 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4713 lemmas, using the graph browser tool;
  4714 
  4715 * Pure: predict failure of "show" in interactive mode;
  4716 
  4717 * Pure: 'thms_containing' now takes actual terms as arguments;
  4718 
  4719 * HOL: improved method 'induct' --- now handles non-atomic goals
  4720 (potential INCOMPATIBILITY); tuned error handling;
  4721 
  4722 * HOL: cases and induct rules now provide explicit hints about the
  4723 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4724 any remaining facts are inserted into the goal verbatim;
  4725 
  4726 * HOL: local contexts (aka cases) may now contain term bindings as
  4727 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4728 the result to be shown in each case;
  4729 
  4730 * HOL: added 'recdef_tc' command;
  4731 
  4732 * isatool convert assists in eliminating legacy ML scripts;
  4733 
  4734 
  4735 *** HOL ***
  4736 
  4737 * HOL/Library: a collection of generic theories to be used together
  4738 with main HOL; the theory loader path already includes this directory
  4739 by default; the following existing theories have been moved here:
  4740 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4741 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4742 
  4743 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4744 modelling and verification task performed in Isabelle/HOL +
  4745 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4746 
  4747 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4748 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4749 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4750 'domain', this makes the theory consistent with mathematical
  4751 literature;
  4752 
  4753 * HOL basics: added overloaded operations "inverse" and "divide"
  4754 (infix "/"), syntax for generic "abs" operation, generic summation
  4755 operator \<Sum>;
  4756 
  4757 * HOL/typedef: simplified package, provide more useful rules (see also
  4758 HOL/subset.thy);
  4759 
  4760 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4761 now expressed as a proper nested rule (old-style tactic scripts may
  4762 require atomize_strip_tac to cope with non-atomic premises);
  4763 
  4764 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4765 to "split_conv" (old name still available for compatibility);
  4766 
  4767 * HOL: improved concrete syntax for strings (e.g. allows translation
  4768 rules with string literals);
  4769 
  4770 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4771  and Fleuriot's mechanization of analysis, including the transcendental
  4772  functions for the reals;
  4773 
  4774 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4775 
  4776 
  4777 *** CTT ***
  4778 
  4779 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4780 "lam" is displayed as TWO lambda-symbols
  4781 
  4782 * CTT: theory Main now available, containing everything (that is, Bool
  4783 and Arith);
  4784 
  4785 
  4786 *** General ***
  4787 
  4788 * Pure: the Simplifier has been implemented properly as a derived rule
  4789 outside of the actual kernel (at last!); the overall performance
  4790 penalty in practical applications is about 50%, while reliability of
  4791 the Isabelle inference kernel has been greatly improved;
  4792 
  4793 * print modes "brackets" and "no_brackets" control output of nested =>
  4794 (types) and ==> (props); the default behaviour is "brackets";
  4795 
  4796 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4797 as assumptions as well;
  4798 
  4799 * system: support Poly/ML 4.0;
  4800 
  4801 * system: isatool install handles KDE version 1 or 2;
  4802 
  4803 
  4804 
  4805 New in Isabelle99-1 (October 2000)
  4806 ----------------------------------
  4807 
  4808 *** Overview of INCOMPATIBILITIES ***
  4809 
  4810 * HOL: simplification of natural numbers is much changed; to partly
  4811 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4812 issue the following ML commands:
  4813 
  4814   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4815   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4816 
  4817 * HOL: simplification no longer dives into case-expressions; this is
  4818 controlled by "t.weak_case_cong" for each datatype t;
  4819 
  4820 * HOL: nat_less_induct renamed to less_induct;
  4821 
  4822 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4823 fixsome to patch .thy and .ML sources automatically;
  4824 
  4825   select_equality  -> some_equality
  4826   select_eq_Ex     -> some_eq_ex
  4827   selectI2EX       -> someI2_ex
  4828   selectI2         -> someI2
  4829   selectI          -> someI
  4830   select1_equality -> some1_equality
  4831   Eps_sym_eq       -> some_sym_eq_trivial
  4832   Eps_eq           -> some_eq_trivial
  4833 
  4834 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4835 
  4836 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4837 instead);
  4838 
  4839 * HOL: the recursion equations generated by 'recdef' are now called
  4840 f.simps instead of f.rules;
  4841 
  4842 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4843 
  4844 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4845 sometimes be needed;
  4846 
  4847 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4848 
  4849 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4850 
  4851 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4852 product is now "<*>" instead of "Times"; the lexicographic product is
  4853 now "<*lex*>" instead of "**";
  4854 
  4855 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4856 of main HOL, but was unused); better use HOL's datatype package;
  4857 
  4858 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4859 the old syntax may be recovered as follows:
  4860 
  4861   syntax (symbols)
  4862     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4863       (infixl "\\<oplus>" 100)
  4864 
  4865 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4866 
  4867 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4868 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4869 internally;
  4870 
  4871 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4872 changed from A/r to A//r;
  4873 
  4874 * ZF: new treatment of arithmetic (nat & int) may break some old
  4875 proofs;
  4876 
  4877 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4878 rulify -> rule_format, elimify -> elim_format, ...);
  4879 
  4880 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4881 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4882 should have to change intro!! to intro? only); replaced "delrule" by
  4883 "rule del";
  4884 
  4885 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4886 
  4887 * Provers: strengthened force_tac by using new first_best_tac;
  4888 
  4889 * LaTeX document preparation: several changes of isabelle.sty (see
  4890 lib/texinputs);
  4891 
  4892 
  4893 *** Document preparation ***
  4894 
  4895 * formal comments (text blocks etc.) in new-style theories may now
  4896 contain antiquotations of thm/prop/term/typ/text to be presented
  4897 according to latex print mode; concrete syntax is like this:
  4898 @{term[show_types] "f(x) = a + x"};
  4899 
  4900 * isatool mkdir provides easy setup of Isabelle session directories,
  4901 including proper document sources;
  4902 
  4903 * generated LaTeX sources are now deleted after successful run
  4904 (isatool document -c); may retain a copy somewhere else via -D option
  4905 of isatool usedir;
  4906 
  4907 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4908 style files, achieving self-contained LaTeX sources and simplifying
  4909 LaTeX debugging;
  4910 
  4911 * old-style theories now produce (crude) LaTeX output as well;
  4912 
  4913 * browser info session directories are now self-contained (may be put
  4914 on WWW server seperately); improved graphs of nested sessions; removed
  4915 graph for 'all sessions';
  4916 
  4917 * several improvements in isabelle style files; \isabellestyle{it}
  4918 produces fake math mode output; \isamarkupheader is now \section by
  4919 default; see lib/texinputs/isabelle.sty etc.;
  4920 
  4921 
  4922 *** Isar ***
  4923 
  4924 * Isar/Pure: local results and corresponding term bindings are now
  4925 subject to Hindley-Milner polymorphism (similar to ML); this
  4926 accommodates incremental type-inference very nicely;
  4927 
  4928 * Isar/Pure: new derived language element 'obtain' supports
  4929 generalized existence reasoning;
  4930 
  4931 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4932 support accumulation of results, without applying any rules yet;
  4933 useful to collect intermediate results without explicit name
  4934 references, and for use with transitivity rules with more than 2
  4935 premises;
  4936 
  4937 * Isar/Pure: scalable support for case-analysis type proofs: new
  4938 'case' language element refers to local contexts symbolically, as
  4939 produced by certain proof methods; internally, case names are attached
  4940 to theorems as "tags";
  4941 
  4942 * Isar/Pure: theory command 'hide' removes declarations from
  4943 class/type/const name spaces;
  4944 
  4945 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4946 indicate potential overloading;
  4947 
  4948 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4949 
  4950 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4951 "{a,b,c}" instead of {a,b,c};
  4952 
  4953 * Isar/Pure now provides its own version of intro/elim/dest
  4954 attributes; useful for building new logics, but beware of confusion
  4955 with the version in Provers/classical;
  4956 
  4957 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4958 case name 'antecedent';
  4959 
  4960 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4961 to the current context is now done automatically);
  4962 
  4963 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4964 for definining proof methods in ML;
  4965 
  4966 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4967 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4968 most cases, one should have to change intro!! to intro? only);
  4969 replaced "delrule" by "rule del";
  4970 
  4971 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4972 'symmetric' attribute (the latter supercedes [RS sym]);
  4973 
  4974 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4975 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4976 well (including splits);
  4977 
  4978 * Isar/Provers: Simplifier and Classical methods now support all kind
  4979 of modifiers used in the past, including 'cong', 'iff', etc.
  4980 
  4981 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4982 of Simplifier and Classical reasoner);
  4983 
  4984 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4985 now support named cases; major packages (inductive, datatype, primrec,
  4986 recdef) support case names and properly name parameters;
  4987 
  4988 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4989 monotonicity conditions are extracted to be proven at end of
  4990 calculations;
  4991 
  4992 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4993 method anyway;
  4994 
  4995 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4996 split_if split_if_asm; datatype package provides theorems foo.splits =
  4997 foo.split foo.split_asm for each datatype;
  4998 
  4999 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5000 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5001 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5002 use "(cases (simplified))" method in proper proof texts);
  5003 
  5004 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5005 
  5006 * Isar: names of theorems etc. may be natural numbers as well;
  5007 
  5008 * Isar: 'pr' command: optional arguments for goals_limit and
  5009 ProofContext.prems_limit; no longer prints theory contexts, but only
  5010 proof states;
  5011 
  5012 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5013 additional print modes to be specified; e.g. "pr(latex)" will print
  5014 proof state according to the Isabelle LaTeX style;
  5015 
  5016 * Isar: improved support for emulating tactic scripts, including proof
  5017 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5018 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5019 (for HOL datatypes);
  5020 
  5021 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5022 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5023 'proof method scripts' have to be in depth-first order;
  5024 
  5025 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5026 
  5027 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5028 should instead use individual commands for printing items
  5029 (print_commands, print_methods etc.);
  5030 
  5031 * Isar: added 'nothing' --- the empty list of theorems;
  5032 
  5033 
  5034 *** HOL ***
  5035 
  5036 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5037 corresponding virtual machine and a specification of its bytecode
  5038 verifier and a lightweight bytecode verifier, including proofs of
  5039 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5040 Cornelia Pusch (see also the homepage of project Bali at
  5041 http://isabelle.in.tum.de/Bali/);
  5042 
  5043 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5044 Clemens Ballarin;
  5045 
  5046 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5047 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5048 Rasmussen;
  5049 
  5050 * HOL/Lattice: fundamental concepts of lattice theory and order
  5051 structures, including duals, properties of bounds versus algebraic
  5052 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5053 Theorem for complete lattices etc.; may also serve as a demonstration
  5054 for abstract algebraic reasoning using axiomatic type classes, and
  5055 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5056 
  5057 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5058 von Oheimb;
  5059 
  5060 * HOL/IMPP: extension of IMP with local variables and mutually
  5061 recursive procedures, by David von Oheimb;
  5062 
  5063 * HOL/Lambda: converted into new-style theory and document;
  5064 
  5065 * HOL/ex/Multiquote: example of multiple nested quotations and
  5066 anti-quotations -- basically a generalized version of de-Bruijn
  5067 representation; very useful in avoiding lifting of operations;
  5068 
  5069 * HOL/record: added general record equality rule to simpset; fixed
  5070 select-update simplification procedure to handle extended records as
  5071 well; admit "r" as field name;
  5072 
  5073 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5074 other numeric types and also as the identity of groups, rings, etc.;
  5075 
  5076 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5077 Types nat and int belong to this axclass;
  5078 
  5079 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5080    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5081    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5082   two terms #m*u and #n*u are replaced by #(m+n)*u
  5083     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5084   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5085     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5086 
  5087 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5088 powerful prover for predicate logic but knows nothing of clasets; see
  5089 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5090 
  5091 * HOL: new version of "case_tac" subsumes both boolean case split and
  5092 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5093 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5094 
  5095 * HOL: simplification no longer dives into case-expressions: only the
  5096 selector expression is simplified, but not the remaining arms; to
  5097 enable full simplification of case-expressions for datatype t, you may
  5098 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5099 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5100 
  5101 * HOL/recdef: the recursion equations generated by 'recdef' for
  5102 function 'f' are now called f.simps instead of f.rules; if all
  5103 termination conditions are proved automatically, these simplification
  5104 rules are added to the simpset, as in primrec; rules may be named
  5105 individually as well, resulting in a separate list of theorems for
  5106 each equation;
  5107 
  5108 * HOL/While is a new theory that provides a while-combinator. It
  5109 permits the definition of tail-recursive functions without the
  5110 provision of a termination measure. The latter is necessary once the
  5111 invariant proof rule for while is applied.
  5112 
  5113 * HOL: new (overloaded) notation for the set of elements below/above
  5114 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5115 
  5116 * HOL: theorems impI, allI, ballI bound as "strip";
  5117 
  5118 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5119 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5120 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5121 
  5122 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5123 
  5124 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5125 main HOL, but was unused);
  5126 
  5127 * HOL: fewer consts declared as global (e.g. have to refer to
  5128 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5129 
  5130 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5131 in case of overlap with user translations (e.g. judgements over
  5132 tuples); (note that the underlying logical represenation is still
  5133 bogus);
  5134 
  5135 
  5136 *** ZF ***
  5137 
  5138 * ZF: simplification automatically cancels common terms in arithmetic
  5139 expressions over nat and int;
  5140 
  5141 * ZF: new treatment of nat to minimize type-checking: all operators
  5142 coerce their operands to a natural number using the function natify,
  5143 making the algebraic laws unconditional;
  5144 
  5145 * ZF: as above, for int: operators coerce their operands to an integer
  5146 using the function intify;
  5147 
  5148 * ZF: the integer library now contains many of the usual laws for the
  5149 orderings, including $<=, and monotonicity laws for $+ and $*;
  5150 
  5151 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5152 simplification;
  5153 
  5154 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5155 to the simplifier and classical reasoner simultaneously;
  5156 
  5157 
  5158 *** General ***
  5159 
  5160 * Provers: blast_tac now handles actual object-logic rules as
  5161 assumptions; note that auto_tac uses blast_tac internally as well;
  5162 
  5163 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5164 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5165 
  5166 * Provers: delrules now handles destruct rules as well (no longer need
  5167 explicit make_elim);
  5168 
  5169 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5170   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5171 use instead the strong form,
  5172   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5173 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5174 from destruct-rules;
  5175 
  5176 * Provers: Simplifier.easy_setup provides a fast path to basic
  5177 Simplifier setup for new object-logics;
  5178 
  5179 * Pure: AST translation rules no longer require constant head on LHS;
  5180 
  5181 * Pure: improved name spaces: ambiguous output is qualified; support
  5182 for hiding of names;
  5183 
  5184 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5185 XSYMBOL_HOME; no longer need to do manual configuration in most
  5186 situations;
  5187 
  5188 * system: compression of ML heaps images may now be controlled via -c
  5189 option of isabelle and isatool usedir (currently only observed by
  5190 Poly/ML);
  5191 
  5192 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5193 useful for remote X11);
  5194 
  5195 * system: provide TAGS file for Isabelle sources;
  5196 
  5197 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5198 order;
  5199 
  5200 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5201 timing flag supersedes proof_timing and Toplevel.trace;
  5202 
  5203 * ML: new combinators |>> and |>>> for incremental transformations
  5204 with secondary results (e.g. certain theory extensions):
  5205 
  5206 * ML: PureThy.add_defs gets additional argument to indicate potential
  5207 overloading (usually false);
  5208 
  5209 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5210 results;
  5211 
  5212 
  5213 
  5214 New in Isabelle99 (October 1999)
  5215 --------------------------------
  5216 
  5217 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5218 
  5219 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5220 are no longer simplified.  (This allows the simplifier to unfold recursive
  5221 functional programs.)  To restore the old behaviour, declare
  5222 
  5223     Delcongs [if_weak_cong];
  5224 
  5225 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5226 complement;
  5227 
  5228 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5229 
  5230 * HOL/datatype: mutual_induct_tac no longer exists --
  5231   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5232 
  5233 * HOL/typedef: fixed type inference for representing set; type
  5234 arguments now have to occur explicitly on the rhs as type constraints;
  5235 
  5236 * ZF: The con_defs part of an inductive definition may no longer refer
  5237 to constants declared in the same theory;
  5238 
  5239 * HOL, ZF: the function mk_cases, generated by the inductive
  5240 definition package, has lost an argument.  To simplify its result, it
  5241 uses the default simpset instead of a supplied list of theorems.
  5242 
  5243 * HOL/List: the constructors of type list are now Nil and Cons;
  5244 
  5245 * Simplifier: the type of the infix ML functions
  5246         setSSolver addSSolver setSolver addSolver
  5247 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5248 for packaging solvers. A solver is created via
  5249         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5250 where the string argument is only a comment.
  5251 
  5252 
  5253 *** Proof tools ***
  5254 
  5255 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5256 decision procedure for linear arithmetic. Currently it is used for
  5257 types `nat', `int', and `real' in HOL (see below); it can, should and
  5258 will be instantiated for other types and logics as well.
  5259 
  5260 * The simplifier now accepts rewrite rules with flexible heads, eg
  5261      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5262   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5263   matching.
  5264 
  5265 
  5266 *** General ***
  5267 
  5268 * New Isabelle/Isar subsystem provides an alternative to traditional
  5269 tactical theorem proving; together with the ProofGeneral/isar user
  5270 interface it offers an interactive environment for developing human
  5271 readable proof documents (Isar == Intelligible semi-automated
  5272 reasoning); for further information see isatool doc isar-ref,
  5273 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5274 
  5275 * improved and simplified presentation of theories: better HTML markup
  5276 (including colors), graph views in several sizes; isatool usedir now
  5277 provides a proper interface for user theories (via -P option); actual
  5278 document preparation based on (PDF)LaTeX is available as well (for
  5279 new-style theories only); see isatool doc system for more information;
  5280 
  5281 * native support for Proof General, both for classic Isabelle and
  5282 Isabelle/Isar;
  5283 
  5284 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5285 using the graph browser tool;
  5286 
  5287 * Isabelle manuals now also available as PDF;
  5288 
  5289 * theory loader rewritten from scratch (may not be fully
  5290 bug-compatible); old loadpath variable has been replaced by show_path,
  5291 add_path, del_path, reset_path functions; new operations such as
  5292 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5293 isatool doc ref);
  5294 
  5295 * improved isatool install: option -k creates KDE application icon,
  5296 option -p DIR installs standalone binaries;
  5297 
  5298 * added ML_PLATFORM setting (useful for cross-platform installations);
  5299 more robust handling of platform specific ML images for SML/NJ;
  5300 
  5301 * the settings environment is now statically scoped, i.e. it is never
  5302 created again in sub-processes invoked from isabelle, isatool, or
  5303 Isabelle;
  5304 
  5305 * path element specification '~~' refers to '$ISABELLE_HOME';
  5306 
  5307 * in locales, the "assumes" and "defines" parts may be omitted if
  5308 empty;
  5309 
  5310 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5311 long arrows);
  5312 
  5313 * new print_mode "HTML";
  5314 
  5315 * new flag show_tags controls display of tags of theorems (which are
  5316 basically just comments that may be attached by some tools);
  5317 
  5318 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5319 mode and goal output format:
  5320 
  5321 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5322 244c244
  5323 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5324 ---
  5325 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5326 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5327 181c181
  5328 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5329 ---
  5330 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5331 
  5332 * function bind_thms stores lists of theorems (cf. bind_thm);
  5333 
  5334 * new shorthand tactics ftac, eatac, datac, fatac;
  5335 
  5336 * qed (and friends) now accept "" as result name; in that case the
  5337 theorem is not stored, but proper checks and presentation of the
  5338 result still apply;
  5339 
  5340 * theorem database now also indexes constants "Trueprop", "all",
  5341 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5342 
  5343 
  5344 *** HOL ***
  5345 
  5346 ** HOL arithmetic **
  5347 
  5348 * There are now decision procedures for linear arithmetic over nat and
  5349 int:
  5350 
  5351 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5352 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5353 are treated as atomic; subformulae not involving type `nat' or `int'
  5354 are ignored; quantified subformulae are ignored unless they are
  5355 positive universal or negative existential. The tactic has to be
  5356 invoked by hand and can be a little bit slow. In particular, the
  5357 running time is exponential in the number of occurrences of `min' and
  5358 `max', and `-' on `nat'.
  5359 
  5360 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5361 (negated) (in)equalities among the premises and the conclusion into
  5362 account (i.e. no compound formulae) and does not know about `min' and
  5363 `max', and `-' on `nat'. It is fast and is used automatically by the
  5364 simplifier.
  5365 
  5366 NB: At the moment, these decision procedures do not cope with mixed
  5367 nat/int formulae where the two parts interact, such as `m < n ==>
  5368 int(m) < int(n)'.
  5369 
  5370 * HOL/Numeral provides a generic theory of numerals (encoded
  5371 efficiently as bit strings); setup for types nat/int/real is in place;
  5372 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5373 int, existing theories and proof scripts may require a few additional
  5374 type constraints;
  5375 
  5376 * integer division and remainder can now be performed on constant
  5377 arguments;
  5378 
  5379 * many properties of integer multiplication, division and remainder
  5380 are now available;
  5381 
  5382 * An interface to the Stanford Validity Checker (SVC) is available through the
  5383 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5384 are proved automatically.  SVC must be installed separately, and its results
  5385 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5386 invocation of the underlying oracle).  For SVC see
  5387   http://verify.stanford.edu/SVC
  5388 
  5389 * IsaMakefile: the HOL-Real target now builds an actual image;
  5390 
  5391 
  5392 ** HOL misc **
  5393 
  5394 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5395 (in Isabelle/Isar) -- by Gertrud Bauer;
  5396 
  5397 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5398 analysis for assembly languages with subtypes;
  5399 
  5400 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5401 -- avoids syntactic ambiguities and treats state, transition, and
  5402 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5403 changed syntax and (many) tactics;
  5404 
  5405 * HOL/inductive: Now also handles more general introduction rules such
  5406   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5407   theorems are now maintained within the theory (maintained via the
  5408   "mono" attribute);
  5409 
  5410 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5411   (using function types) such as
  5412 
  5413   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5414 
  5415 * HOL/record: record_simproc (part of the default simpset) takes care
  5416 of selectors applied to updated records; record_split_tac is no longer
  5417 part of the default claset; update_defs may now be removed from the
  5418 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5419 
  5420   claset_ref () := claset() addSWrapper record_split_wrapper;
  5421   Delsimprocs [record_simproc]
  5422 
  5423 * HOL/typedef: fixed type inference for representing set; type
  5424 arguments now have to occur explicitly on the rhs as type constraints;
  5425 
  5426 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5427 names rather than an ML expression;
  5428 
  5429 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5430 supplied later.  Program schemes can be defined, such as
  5431     "While B C s = (if B s then While B C (C s) else s)"
  5432 where the well-founded relation can be chosen after B and C have been given.
  5433 
  5434 * HOL/List: the constructors of type list are now Nil and Cons;
  5435 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5436 course, ML tools referring to List.list.op # etc. have to be adapted;
  5437 
  5438 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5439 disabled by default; run isabelle with option -m HOL to get back to
  5440 the original Gordon/HOL-style output;
  5441 
  5442 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5443 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5444 
  5445 * HOL basic syntax simplified (more orthogonal): all variants of
  5446 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5447 Eps operator is provided as well: "SOME x. P[x]";
  5448 
  5449 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5450 
  5451 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5452 thus available for user theories;
  5453 
  5454 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5455 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5456 time;
  5457 
  5458 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5459 several times and then mp;
  5460 
  5461 
  5462 *** LK ***
  5463 
  5464 * the notation <<...>> is now available as a notation for sequences of
  5465 formulas;
  5466 
  5467 * the simplifier is now installed
  5468 
  5469 * the axiom system has been generalized (thanks to Soren Heilmann)
  5470 
  5471 * the classical reasoner now has a default rule database
  5472 
  5473 
  5474 *** ZF ***
  5475 
  5476 * new primrec section allows primitive recursive functions to be given
  5477 directly (as in HOL) over datatypes and the natural numbers;
  5478 
  5479 * new tactics induct_tac and exhaust_tac for induction (or case
  5480 analysis) over datatypes and the natural numbers;
  5481 
  5482 * the datatype declaration of type T now defines the recursor T_rec;
  5483 
  5484 * simplification automatically does freeness reasoning for datatype
  5485 constructors;
  5486 
  5487 * automatic type-inference, with AddTCs command to insert new
  5488 type-checking rules;
  5489 
  5490 * datatype introduction rules are now added as Safe Introduction rules
  5491 to the claset;
  5492 
  5493 * the syntax "if P then x else y" is now available in addition to
  5494 if(P,x,y);
  5495 
  5496 
  5497 *** Internal programming interfaces ***
  5498 
  5499 * tuned simplifier trace output; new flag debug_simp;
  5500 
  5501 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5502 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5503 
  5504 * AxClass.axclass_tac lost the theory argument;
  5505 
  5506 * tuned current_goals_markers semantics: begin / end goal avoids
  5507 printing empty lines;
  5508 
  5509 * removed prs and prs_fn hook, which was broken because it did not
  5510 include \n in its semantics, forcing writeln to add one
  5511 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5512 string -> unit if you really want to output text without newline;
  5513 
  5514 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5515 plain output, interface builders may have to enable 'isabelle_font'
  5516 mode to get Isabelle font glyphs as before;
  5517 
  5518 * refined token_translation interface; INCOMPATIBILITY: output length
  5519 now of type real instead of int;
  5520 
  5521 * theory loader actions may be traced via new ThyInfo.add_hook
  5522 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5523 your own database of information attached to *whole* theories -- as
  5524 opposed to intra-theory data slots offered via TheoryDataFun;
  5525 
  5526 * proper handling of dangling sort hypotheses (at last!);
  5527 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5528 extra sort hypotheses that can be witnessed from the type signature;
  5529 the force_strip_shyps flag is gone, any remaining shyps are simply
  5530 left in the theorem (with a warning issued by strip_shyps_warning);
  5531 
  5532 
  5533 
  5534 New in Isabelle98-1 (October 1998)
  5535 ----------------------------------
  5536 
  5537 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5538 
  5539 * several changes of automated proof tools;
  5540 
  5541 * HOL: major changes to the inductive and datatype packages, including
  5542 some minor incompatibilities of theory syntax;
  5543 
  5544 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5545 called `inj_on';
  5546 
  5547 * HOL: removed duplicate thms in Arith:
  5548   less_imp_add_less  should be replaced by  trans_less_add1
  5549   le_imp_add_le      should be replaced by  trans_le_add1
  5550 
  5551 * HOL: unary minus is now overloaded (new type constraints may be
  5552 required);
  5553 
  5554 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5555 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5556 now taken as an integer constant.
  5557 
  5558 * Pure: ML function 'theory_of' renamed to 'theory';
  5559 
  5560 
  5561 *** Proof tools ***
  5562 
  5563 * Simplifier:
  5564   1. Asm_full_simp_tac is now more aggressive.
  5565      1. It will sometimes reorient premises if that increases their power to
  5566         simplify.
  5567      2. It does no longer proceed strictly from left to right but may also
  5568         rotate premises to achieve further simplification.
  5569      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5570      old Asm_full_simp_tac in that it does not rotate premises.
  5571   2. The simplifier now knows a little bit about nat-arithmetic.
  5572 
  5573 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5574 allows for selected deletion of wrappers, by introduction of names for
  5575 wrapper functionals.  This implies that addbefore, addSbefore,
  5576 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5577 and that adding two tactics with the same name overwrites the first
  5578 one (emitting a warning).
  5579   type wrapper = (int -> tactic) -> (int -> tactic)
  5580   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5581   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5582   delWrapper, delSWrapper: claset *  string            -> claset
  5583   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5584 
  5585 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5586 semantics; addbefore now affects only the unsafe part of step_tac
  5587 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5588 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5589 by Force_tac;
  5590 
  5591 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5592 compWrapper; added safe wrapper (and access functions for it);
  5593 
  5594 * HOL/split_all_tac is now much faster and fails if there is nothing
  5595 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5596 and the names of the automatically generated variables have changed.
  5597 split_all_tac has moved within claset() from unsafe wrappers to safe
  5598 wrappers, which means that !!-bound variables are split much more
  5599 aggressively, and safe_tac and clarify_tac now split such variables.
  5600 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5601 Note: the same holds for record_split_tac, which does the job of
  5602 split_all_tac for record fields.
  5603 
  5604 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5605 permanently to the default simpset using Addsplits just like
  5606 Addsimps. They can be removed via Delsplits just like
  5607 Delsimps. Lower-case versions are also available.
  5608 
  5609 * HOL/Simplifier: The rule split_if is now part of the default
  5610 simpset. This means that the simplifier will eliminate all occurrences
  5611 of if-then-else in the conclusion of a goal. To prevent this, you can
  5612 either remove split_if completely from the default simpset by
  5613 `Delsplits [split_if]' or remove it in a specific call of the
  5614 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5615 other case splitting rules to/from the default simpset: every datatype
  5616 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5617 t is the name of the datatype).
  5618 
  5619 * Classical reasoner / Simplifier combination: new force_tac (and
  5620 derivatives Force_tac, force) combines rewriting and classical
  5621 reasoning (and whatever other tools) similarly to auto_tac, but is
  5622 aimed to solve the given subgoal completely.
  5623 
  5624 
  5625 *** General ***
  5626 
  5627 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5628 and `goalw': the theory is no longer needed as an explicit argument -
  5629 the current theory context is used; assumptions are no longer returned
  5630 at the ML-level unless one of them starts with ==> or !!; it is
  5631 recommended to convert to these new commands using isatool fixgoal
  5632 (backup your sources first!);
  5633 
  5634 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5635 the current theory context, and 'theory' to lookup stored theories;
  5636 
  5637 * new theory section 'locale' for declaring constants, assumptions and
  5638 definitions that have local scope;
  5639 
  5640 * new theory section 'nonterminals' for purely syntactic types;
  5641 
  5642 * new theory section 'setup' for generic ML setup functions
  5643 (e.g. package initialization);
  5644 
  5645 * the distribution now includes Isabelle icons: see
  5646 lib/logo/isabelle-{small,tiny}.xpm;
  5647 
  5648 * isatool install - install binaries with absolute references to
  5649 ISABELLE_HOME/bin;
  5650 
  5651 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5652 
  5653 * print mode 'emacs' reserved for Isamode;
  5654 
  5655 * support multiple print (ast) translations per constant name;
  5656 
  5657 * theorems involving oracles are now printed with a suffixed [!];
  5658 
  5659 
  5660 *** HOL ***
  5661 
  5662 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5663 
  5664 * HOL/inductive package reorganized and improved: now supports mutual
  5665 definitions such as
  5666 
  5667   inductive EVEN ODD
  5668     intrs
  5669       null "0 : EVEN"
  5670       oddI "n : EVEN ==> Suc n : ODD"
  5671       evenI "n : ODD ==> Suc n : EVEN"
  5672 
  5673 new theorem list "elims" contains an elimination rule for each of the
  5674 recursive sets; inductive definitions now handle disjunctive premises
  5675 correctly (also ZF);
  5676 
  5677 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5678 "mutual_induct" no longer exists - the induction rule is always
  5679 contained in "induct";
  5680 
  5681 
  5682 * HOL/datatype package re-implemented and greatly improved: now
  5683 supports mutually recursive datatypes such as
  5684 
  5685   datatype
  5686     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5687             | SUM ('a aexp) ('a aexp)
  5688             | DIFF ('a aexp) ('a aexp)
  5689             | NUM 'a
  5690   and
  5691     'a bexp = LESS ('a aexp) ('a aexp)
  5692             | AND ('a bexp) ('a bexp)
  5693             | OR ('a bexp) ('a bexp)
  5694 
  5695 as well as indirectly recursive datatypes such as
  5696 
  5697   datatype
  5698     ('a, 'b) term = Var 'a
  5699                   | App 'b ((('a, 'b) term) list)
  5700 
  5701 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5702 induction on mutually / indirectly recursive datatypes.
  5703 
  5704 Primrec equations are now stored in theory and can be accessed via
  5705 <function_name>.simps.
  5706 
  5707 INCOMPATIBILITIES:
  5708 
  5709   - Theories using datatypes must now have theory Datatype as an
  5710     ancestor.
  5711   - The specific <typename>.induct_tac no longer exists - use the
  5712     generic induct_tac instead.
  5713   - natE has been renamed to nat.exhaust - use exhaust_tac
  5714     instead of res_inst_tac ... natE. Note that the variable
  5715     names in nat.exhaust differ from the names in natE, this
  5716     may cause some "fragile" proofs to fail.
  5717   - The theorems split_<typename>_case and split_<typename>_case_asm
  5718     have been renamed to <typename>.split and <typename>.split_asm.
  5719   - Since default sorts of type variables are now handled correctly,
  5720     some datatype definitions may have to be annotated with explicit
  5721     sort constraints.
  5722   - Primrec definitions no longer require function name and type
  5723     of recursive argument.
  5724 
  5725 Consider using isatool fixdatatype to adapt your theories and proof
  5726 scripts to the new package (backup your sources first!).
  5727 
  5728 
  5729 * HOL/record package: considerably improved implementation; now
  5730 includes concrete syntax for record types, terms, updates; theorems
  5731 for surjective pairing and splitting !!-bound record variables; proof
  5732 support is as follows:
  5733 
  5734   1) standard conversions (selectors or updates applied to record
  5735 constructor terms) are part of the standard simpset;
  5736 
  5737   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5738 made part of standard simpset and claset via addIffs;
  5739 
  5740   3) a tactic for record field splitting (record_split_tac) is part of
  5741 the standard claset (addSWrapper);
  5742 
  5743 To get a better idea about these rules you may retrieve them via
  5744 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5745 the name of your record type.
  5746 
  5747 The split tactic 3) conceptually simplifies by the following rule:
  5748 
  5749   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5750 
  5751 Thus any record variable that is bound by meta-all will automatically
  5752 blow up into some record constructor term, consequently the
  5753 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5754 solve record problems automatically.
  5755 
  5756 
  5757 * reorganized the main HOL image: HOL/Integ and String loaded by
  5758 default; theory Main includes everything;
  5759 
  5760 * automatic simplification of integer sums and comparisons, using cancellation;
  5761 
  5762 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5763 
  5764 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5765 
  5766 * many new identities for unions, intersections, set difference, etc.;
  5767 
  5768 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5769 called split_if, split_split, split_sum_case and split_nat_case (to go
  5770 with add/delsplits);
  5771 
  5772 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5773 (?x::unit) = (); this is made part of the default simpset, which COULD
  5774 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5775 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5776 unit_abs_eta_conv is added in order to counter the effect of
  5777 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5778 %u.f();
  5779 
  5780 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5781 makes more sense);
  5782 
  5783 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5784   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5785   disjointness reasoning but breaking a few old proofs.
  5786 
  5787 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5788 to 'converse' from 'inverse' (for compatibility with ZF and some
  5789 literature);
  5790 
  5791 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5792 the well-founded relation;
  5793 
  5794 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5795     Compl A.  The "Compl" syntax remains available as input syntax for this
  5796     release ONLY.
  5797 
  5798 * HOL/Update: new theory of function updates:
  5799     f(a:=b) == %x. if x=a then b else f x
  5800 may also be iterated as in f(a:=b,c:=d,...);
  5801 
  5802 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5803 
  5804 * HOL/List:
  5805   - new function list_update written xs[i:=v] that updates the i-th
  5806     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5807   - new function `upt' written [i..j(] which generates the list
  5808     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5809     bound write [i..j], which is a shorthand for [i..j+1(].
  5810   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5811 
  5812 * HOL/Arith:
  5813   - removed 'pred' (predecessor) function;
  5814   - generalized some theorems about n-1;
  5815   - many new laws about "div" and "mod";
  5816   - new laws about greatest common divisors (see theory ex/Primes);
  5817 
  5818 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5819 instead of "inverse";
  5820 
  5821 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5822   of the multiset ordering;
  5823 
  5824 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5825   (not included by default);
  5826 
  5827 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5828 
  5829 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5830   programs, i.e. different program variables may have different types.
  5831 
  5832 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5833   [previously, this check worked only if the rewrite rule was unconditional]
  5834   Now rew can involve either definitions or equalities (either == or =).
  5835 
  5836 
  5837 *** ZF ***
  5838 
  5839 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5840   only the theorems proved on ZF.ML;
  5841 
  5842 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5843   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5844   disjointness reasoning but breaking a few old proofs.
  5845 
  5846 * ZF/Update: new theory of function updates
  5847     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5848   may also be iterated as in f(a:=b,c:=d,...);
  5849 
  5850 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5851 
  5852 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5853   [previously, this check worked only if the rewrite rule was unconditional]
  5854   Now rew can involve either definitions or equalities (either == or =).
  5855 
  5856 * case_tac provided for compatibility with HOL
  5857     (like the old excluded_middle_tac, but with subgoals swapped)
  5858 
  5859 
  5860 *** Internal programming interfaces ***
  5861 
  5862 * Pure: several new basic modules made available for general use, see
  5863 also src/Pure/README;
  5864 
  5865 * improved the theory data mechanism to support encapsulation (data
  5866 kind name replaced by private Object.kind, acting as authorization
  5867 key); new type-safe user interface via functor TheoryDataFun; generic
  5868 print_data function becomes basically useless;
  5869 
  5870 * removed global_names compatibility flag -- all theory declarations
  5871 are qualified by default;
  5872 
  5873 * module Pure/Syntax now offers quote / antiquote translation
  5874 functions (useful for Hoare logic etc. with implicit dependencies);
  5875 see HOL/ex/Antiquote for an example use;
  5876 
  5877 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5878 cterm -> thm;
  5879 
  5880 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5881 subgoal;
  5882 
  5883 * Display.print_goals function moved to Locale.print_goals;
  5884 
  5885 * standard print function for goals supports current_goals_markers
  5886 variable for marking begin of proof, end of proof, start of goal; the
  5887 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5888 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5889 for example;
  5890 
  5891 
  5892 
  5893 New in Isabelle98 (January 1998)
  5894 --------------------------------
  5895 
  5896 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5897 
  5898 * changed lexical syntax of terms / types: dots made part of long
  5899 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5900 
  5901 * simpset (and claset) reference variable replaced by functions
  5902 simpset / simpset_ref;
  5903 
  5904 * no longer supports theory aliases (via merge) and non-trivial
  5905 implicit merge of thms' signatures;
  5906 
  5907 * most internal names of constants changed due to qualified names;
  5908 
  5909 * changed Pure/Sequence interface (see Pure/seq.ML);
  5910 
  5911 
  5912 *** General Changes ***
  5913 
  5914 * hierachically structured name spaces (for consts, types, axms, thms
  5915 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5916 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5917 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5918 long_names for fully qualified output names; NOTE: ML programs
  5919 (special tactics, packages etc.) referring to internal names may have
  5920 to be adapted to cope with fully qualified names; in case of severe
  5921 backward campatibility problems try setting 'global_names' at compile
  5922 time to have enrything declared within a flat name space; one may also
  5923 fine tune name declarations in theories via the 'global' and 'local'
  5924 section;
  5925 
  5926 * reimplemented the implicit simpset and claset using the new anytype
  5927 data filed in signatures; references simpset:simpset ref etc. are
  5928 replaced by functions simpset:unit->simpset and
  5929 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5930 to patch your ML files accordingly;
  5931 
  5932 * HTML output now includes theory graph data for display with Java
  5933 applet or isatool browser; data generated automatically via isatool
  5934 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5935 
  5936 * defs may now be conditional; improved rewrite_goals_tac to handle
  5937 conditional equations;
  5938 
  5939 * defs now admits additional type arguments, using TYPE('a) syntax;
  5940 
  5941 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5942 creates a new theory node; implicit merge of thms' signatures is
  5943 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5944 transfer:theory->thm->thm in (rare) cases;
  5945 
  5946 * improved handling of draft signatures / theories; draft thms (and
  5947 ctyps, cterms) are automatically promoted to real ones;
  5948 
  5949 * slightly changed interfaces for oracles: admit many per theory, named
  5950 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5951 
  5952 * print_goals: optional output of const types (set show_consts and
  5953 show_types);
  5954 
  5955 * improved output of warnings (###) and errors (***);
  5956 
  5957 * subgoal_tac displays a warning if the new subgoal has type variables;
  5958 
  5959 * removed old README and Makefiles;
  5960 
  5961 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5962 
  5963 * removed obsolete init_pps and init_database;
  5964 
  5965 * deleted the obsolete tactical STATE, which was declared by
  5966     fun STATE tacfun st = tacfun st st;
  5967 
  5968 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5969 (which abbreviates $HOME);
  5970 
  5971 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5972 use isatool fixseq to adapt your ML programs (this works for fully
  5973 qualified references to the Sequence structure only!);
  5974 
  5975 * use_thy no longer requires writable current directory; it always
  5976 reloads .ML *and* .thy file, if either one is out of date;
  5977 
  5978 
  5979 *** Classical Reasoner ***
  5980 
  5981 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5982 tactics that use classical reasoning to simplify a subgoal without
  5983 splitting it into several subgoals;
  5984 
  5985 * Safe_tac: like safe_tac but uses the default claset;
  5986 
  5987 
  5988 *** Simplifier ***
  5989 
  5990 * added simplification meta rules:
  5991     (asm_)(full_)simplify: simpset -> thm -> thm;
  5992 
  5993 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5994 logics (again);
  5995 
  5996 * added prems argument to simplification procedures;
  5997 
  5998 * HOL, FOL, ZF: added infix function `addsplits':
  5999   instead of `<simpset> setloop (split_tac <thms>)'
  6000   you can simply write `<simpset> addsplits <thms>'
  6001 
  6002 
  6003 *** Syntax ***
  6004 
  6005 * TYPE('a) syntax for type reflection terms;
  6006 
  6007 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6008 
  6009 * pretty printer: changed order of mixfix annotation preference (again!);
  6010 
  6011 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6012 
  6013 
  6014 *** HOL ***
  6015 
  6016 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6017   with `addloop' of the simplifier to faciliate case splitting in premises.
  6018 
  6019 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6020 
  6021 * HOL/Auth: new protocol proofs including some for the Internet
  6022   protocol TLS;
  6023 
  6024 * HOL/Map: new theory of `maps' a la VDM;
  6025 
  6026 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6027 cancelling out common nat summands from =, <, <= (in)equalities, or
  6028 differences; simplification procedures nat_cancel_factor for
  6029 cancelling common factor from =, <, <= (in)equalities over natural
  6030 sums; nat_cancel contains both kinds of procedures, it is installed by
  6031 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6032 
  6033 * HOL/simplifier: terms of the form
  6034   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6035   are rewritten to
  6036   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6037   and those of the form
  6038   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6039   are rewritten to
  6040   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6041 
  6042 * HOL/datatype
  6043   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6044 
  6045   P(t_case f1 ... fn x) =
  6046      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6047         ...
  6048        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6049      )
  6050 
  6051   and a theorem `split_t_case_asm' of the form
  6052 
  6053   P(t_case f1 ... fn x) =
  6054     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6055         ...
  6056        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6057      )
  6058   which can be added to a simpset via `addsplits'. The existing theorems
  6059   expand_list_case and expand_option_case have been renamed to
  6060   split_list_case and split_option_case.
  6061 
  6062 * HOL/Arithmetic:
  6063   - `pred n' is automatically converted to `n-1'.
  6064     Users are strongly encouraged not to use `pred' any longer,
  6065     because it will disappear altogether at some point.
  6066   - Users are strongly encouraged to write "0 < n" rather than
  6067     "n ~= 0". Theorems and proof tools have been modified towards this
  6068     `standard'.
  6069 
  6070 * HOL/Lists:
  6071   the function "set_of_list" has been renamed "set" (and its theorems too);
  6072   the function "nth" now takes its arguments in the reverse order and
  6073   has acquired the infix notation "!" as in "xs!n".
  6074 
  6075 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6076 
  6077 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6078   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6079 
  6080 * HOL/record: extensible records with schematic structural subtyping
  6081 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6082 still lacks various theorems and concrete record syntax;
  6083 
  6084 
  6085 *** HOLCF ***
  6086 
  6087 * removed "axioms" and "generated by" sections;
  6088 
  6089 * replaced "ops" section by extended "consts" section, which is capable of
  6090   handling the continuous function space "->" directly;
  6091 
  6092 * domain package:
  6093   . proves theorems immediately and stores them in the theory,
  6094   . creates hierachical name space,
  6095   . now uses normal mixfix annotations (instead of cinfix...),
  6096   . minor changes to some names and values (for consistency),
  6097   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6098   . separator between mutual domain defs: changed "," to "and",
  6099   . improved handling of sort constraints;  now they have to
  6100     appear on the left-hand side of the equations only;
  6101 
  6102 * fixed LAM <x,y,zs>.b syntax;
  6103 
  6104 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6105 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6106 
  6107 
  6108 *** FOL and ZF ***
  6109 
  6110 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6111   with `addloop' of the simplifier to faciliate case splitting in premises.
  6112 
  6113 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6114 in HOL, they strip ALL and --> from proved theorems;
  6115 
  6116 
  6117 
  6118 New in Isabelle94-8 (May 1997)
  6119 ------------------------------
  6120 
  6121 *** General Changes ***
  6122 
  6123 * new utilities to build / run / maintain Isabelle etc. (in parts
  6124 still somewhat experimental); old Makefiles etc. still functional;
  6125 
  6126 * new 'Isabelle System Manual';
  6127 
  6128 * INSTALL text, together with ./configure and ./build scripts;
  6129 
  6130 * reimplemented type inference for greater efficiency, better error
  6131 messages and clean internal interface;
  6132 
  6133 * prlim command for dealing with lots of subgoals (an easier way of
  6134 setting goals_limit);
  6135 
  6136 
  6137 *** Syntax ***
  6138 
  6139 * supports alternative (named) syntax tables (parser and pretty
  6140 printer); internal interface is provided by add_modesyntax(_i);
  6141 
  6142 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6143 be used in conjunction with the Isabelle symbol font; uses the
  6144 "symbols" syntax table;
  6145 
  6146 * added token_translation interface (may translate name tokens in
  6147 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6148 the current print_mode); IMPORTANT: user print translation functions
  6149 are responsible for marking newly introduced bounds
  6150 (Syntax.mark_boundT);
  6151 
  6152 * token translations for modes "xterm" and "xterm_color" that display
  6153 names in bold, underline etc. or colors (which requires a color
  6154 version of xterm);
  6155 
  6156 * infixes may now be declared with names independent of their syntax;
  6157 
  6158 * added typed_print_translation (like print_translation, but may
  6159 access type of constant);
  6160 
  6161 
  6162 *** Classical Reasoner ***
  6163 
  6164 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6165 some limitations.  Blast_tac...
  6166   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6167   + ignores elimination rules that don't have the correct format
  6168         (the conclusion MUST be a formula variable)
  6169   + ignores types, which can make HOL proofs fail
  6170   + rules must not require higher-order unification, e.g. apply_type in ZF
  6171     [message "Function Var's argument not a bound variable" relates to this]
  6172   + its proof strategy is more general but can actually be slower
  6173 
  6174 * substitution with equality assumptions no longer permutes other
  6175 assumptions;
  6176 
  6177 * minor changes in semantics of addafter (now called addaltern); renamed
  6178 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6179 (and access functions for it);
  6180 
  6181 * improved combination of classical reasoner and simplifier:
  6182   + functions for handling clasimpsets
  6183   + improvement of addss: now the simplifier is called _after_ the
  6184     safe steps.
  6185   + safe variant of addss called addSss: uses safe simplifications
  6186     _during_ the safe steps. It is more complete as it allows multiple
  6187     instantiations of unknowns (e.g. with slow_tac).
  6188 
  6189 *** Simplifier ***
  6190 
  6191 * added interface for simplification procedures (functions that
  6192 produce *proven* rewrite rules on the fly, depending on current
  6193 redex);
  6194 
  6195 * ordering on terms as parameter (used for ordered rewriting);
  6196 
  6197 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6198 
  6199 * the solver is now split into a safe and an unsafe part.
  6200 This should be invisible for the normal user, except that the
  6201 functions setsolver and addsolver have been renamed to setSolver and
  6202 addSolver; added safe_asm_full_simp_tac;
  6203 
  6204 
  6205 *** HOL ***
  6206 
  6207 * a generic induction tactic `induct_tac' which works for all datatypes and
  6208 also for type `nat';
  6209 
  6210 * a generic case distinction tactic `exhaust_tac' which works for all
  6211 datatypes and also for type `nat';
  6212 
  6213 * each datatype comes with a function `size';
  6214 
  6215 * patterns in case expressions allow tuple patterns as arguments to
  6216 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6217 
  6218 * primrec now also works with type nat;
  6219 
  6220 * recdef: a new declaration form, allows general recursive functions to be
  6221 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6222 
  6223 * the constant for negation has been renamed from "not" to "Not" to
  6224 harmonize with FOL, ZF, LK, etc.;
  6225 
  6226 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6227 infinite lists;
  6228 
  6229 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6230 
  6231 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6232 problems in commutative rings, using axiomatic type classes for + and *;
  6233 
  6234 * more examples in HOL/MiniML and HOL/Auth;
  6235 
  6236 * more default rewrite rules for quantifiers, union/intersection;
  6237 
  6238 * a new constant `arbitrary == @x.False';
  6239 
  6240 * HOLCF/IOA replaces old HOL/IOA;
  6241 
  6242 * HOLCF changes: derived all rules and arities
  6243   + axiomatic type classes instead of classes
  6244   + typedef instead of faking type definitions
  6245   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6246   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6247   + eliminated the types void, one, tr
  6248   + use unit lift and bool lift (with translations) instead of one and tr
  6249   + eliminated blift from Lift3.thy (use Def instead of blift)
  6250   all eliminated rules are derived as theorems --> no visible changes ;
  6251 
  6252 
  6253 *** ZF ***
  6254 
  6255 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6256 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6257 as ZF_cs addSIs [equalityI];
  6258