NEWS
author haftmann
Wed Jul 22 14:21:52 2009 +0200 (2009-07-22)
changeset 32136 672dfd59ff03
parent 32131 7913823f14e3
parent 32134 ee143615019c
child 32151 2f65c45c2e7e
permissions -rw-r--r--
merged
     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 * More convenient names for set intersection and union.  INCOMPATIBILITY:
    22 
    23     Set.Int ~>  Set.inter
    24     Set.Un ~>   Set.union
    25 
    26 * Code generator attributes follow the usual underscore convention:
    27     code_unfold     replaces    code unfold
    28     code_post       replaces    code post
    29     etc.
    30   INCOMPATIBILITY.
    31 
    32 * New quickcheck implementation using new code generator.
    33 
    34 * New type class boolean_algebra.
    35 
    36 * Refinements to lattices classes:
    37   - added boolean_algebra type class
    38   - less default intro/elim rules in locale variant, more default
    39     intro/elim rules in class variant: more uniformity
    40   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    41   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    42   - renamed ACI to inf_sup_aci
    43 
    44 * Class semiring_div requires superclass no_zero_divisors and proof of
    45 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    46 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    47 generalized to class semiring_div, subsuming former theorems
    48 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    49 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    50 INCOMPATIBILITY.
    51 
    52 * Power operations on relations and functions are now one dedicate
    53 constant compow with infix syntax "^^".  Power operations on
    54 multiplicative monoids retains syntax "^" and is now defined generic
    55 in class power.  INCOMPATIBILITY.
    56 
    57 * GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm of finite and
    58 infinite sets. It is shown that they form a complete lattice.
    59 
    60 * ML antiquotation @{code_datatype} inserts definition of a datatype
    61 generated by the code generator; see Predicate.thy for an example.
    62 
    63 * New method "linarith" invokes existing linear arithmetic decision
    64 procedure only.
    65 
    66 * Implementation of quickcheck using generic code generator; default
    67 generators are provided for all suitable HOL types, records and
    68 datatypes.
    69 
    70 * Constants Set.Pow and Set.image now with authentic syntax;
    71 object-logic definitions Set.Pow_def and Set.image_def.
    72 INCOMPATIBILITY.
    73 
    74 * Renamed theorems:
    75 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    76 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    77 Suc_plus1 -> Suc_eq_plus1
    78 
    79 * New sledgehammer option "Full Types" in Proof General settings menu.
    80 Causes full type information to be output to the ATPs.  This slows
    81 ATPs down considerably but eliminates a source of unsound "proofs"
    82 that fail later.
    83 
    84 * Discontinued ancient tradition to suffix certain ML module names
    85 with "_package", e.g.:
    86 
    87     DatatypePackage ~> Datatype
    88     InductivePackage ~> Inductive
    89 
    90     etc.
    91 
    92 INCOMPATIBILITY.
    93 
    94 * NewNumberTheory: Jeremy Avigad's new version of part of
    95 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
    96 
    97 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    98 
    99 * Abbreviation "arbitrary" of "undefined" has disappeared; use
   100 "undefined" directly.  INCOMPATIBILITY.
   101 
   102 * New evaluator "approximate" approximates an real valued term using
   103 the same method as the approximation method.
   104 
   105 * Method "approximate" supports now arithmetic expressions as
   106 boundaries of intervals and implements interval splitting and Taylor
   107 series expansion.
   108 
   109 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   110 the theorems in DERIV_intros assumes composition with an additional
   111 function and matches a variable to the derivative, which has to be
   112 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   113 the derivative of most elementary terms.
   114 
   115 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   116 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   117 
   118 
   119 *** ML ***
   120 
   121 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   122 functors have their own ML name space there is no point to mark them
   123 separately.)  Minor INCOMPATIBILITY.
   124 
   125 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   126 
   127 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   128 cominators for "args".  INCOMPATIBILITY, need to use simplified
   129 Attrib/Method.setup introduced in Isabelle2009.
   130 
   131 * Display.pretty_thm now requires a proper context (cf. former
   132 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   133 or even Display.pretty_thm_without_context as last resort.
   134 INCOMPATIBILITY.
   135 
   136 
   137 *** System ***
   138 
   139 * Discontinued support for Poly/ML 4.x versions.
   140 
   141 * Removed "compress" option from isabelle-process and isabelle usedir;
   142 this is always enabled.
   143 
   144 * More fine-grained control of proof parallelism, cf.
   145 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   146 
   147 
   148 
   149 New in Isabelle2009 (April 2009)
   150 --------------------------------
   151 
   152 *** General ***
   153 
   154 * Simplified main Isabelle executables, with less surprises on
   155 case-insensitive file-systems (such as Mac OS).
   156 
   157   - The main Isabelle tool wrapper is now called "isabelle" instead of
   158     "isatool."
   159 
   160   - The former "isabelle" alias for "isabelle-process" has been
   161     removed (should rarely occur to regular users).
   162 
   163   - The former "isabelle-interface" and its alias "Isabelle" have been
   164     removed (interfaces are now regular Isabelle tools).
   165 
   166 Within scripts and make files, the Isabelle environment variables
   167 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   168 respectively.  (The latter are still available as legacy feature.)
   169 
   170 The old isabelle-interface wrapper could react in confusing ways if
   171 the interface was uninstalled or changed otherwise.  Individual
   172 interface tool configuration is now more explicit, see also the
   173 Isabelle system manual.  In particular, Proof General is now available
   174 via "isabelle emacs".
   175 
   176 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   177 purge installed copies of Isabelle executables and re-run "isabelle
   178 install -p ...", or use symlinks.
   179 
   180 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   181 old ~/isabelle, which was slightly non-standard and apt to cause
   182 surprises on case-insensitive file-systems (such as Mac OS).
   183 
   184 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   185 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   186 care is required when using older releases of Isabelle.  Note that
   187 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   188 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   189 
   190 * Proofs of fully specified statements are run in parallel on
   191 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   192 a regular 4-core machine, if the initial heap space is made reasonably
   193 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   194 
   195 * The main reference manuals ("isar-ref", "implementation", and
   196 "system") have been updated and extended.  Formally checked references
   197 as hyperlinks are now available uniformly.
   198 
   199 
   200 *** Pure ***
   201 
   202 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   203 respects.  The most important changes are listed below.  See the
   204 Tutorial on Locales ("locales" manual) for details.
   205 
   206 - In locale expressions, instantiation replaces renaming.  Parameters
   207 must be declared in a for clause.  To aid compatibility with previous
   208 parameter inheritance, in locale declarations, parameters that are not
   209 'touched' (instantiation position "_" or omitted) are implicitly added
   210 with their syntax at the beginning of the for clause.
   211 
   212 - Syntax from abbreviations and definitions in locales is available in
   213 locale expressions and context elements.  The latter is particularly
   214 useful in locale declarations.
   215 
   216 - More flexible mechanisms to qualify names generated by locale
   217 expressions.  Qualifiers (prefixes) may be specified in locale
   218 expressions, and can be marked as mandatory (syntax: "name!:") or
   219 optional (syntax "name?:").  The default depends for plain "name:"
   220 depends on the situation where a locale expression is used: in
   221 commands 'locale' and 'sublocale' prefixes are optional, in
   222 'interpretation' and 'interpret' prefixes are mandatory.  The old
   223 implicit qualifiers derived from the parameter names of a locale are
   224 no longer generated.
   225 
   226 - Command "sublocale l < e" replaces "interpretation l < e".  The
   227 instantiation clause in "interpretation" and "interpret" (square
   228 brackets) is no longer available.  Use locale expressions.
   229 
   230 - When converting proof scripts, mandatory qualifiers in
   231 'interpretation' and 'interpret' should be retained by default, even
   232 if this is an INCOMPATIBILITY compared to former behavior.  In the
   233 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   234 in locale expressions range over a single locale instance only.
   235 
   236 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   237 In existing theorem specifications replace the includes element by the
   238 respective context elements of the included locale, omitting those
   239 that are already present in the theorem specification.  Multiple
   240 assume elements of a locale should be replaced by a single one
   241 involving the locale predicate.  In the proof body, declarations (most
   242 notably theorems) may be regained by interpreting the respective
   243 locales in the proof context as required (command "interpret").
   244 
   245 If using "includes" in replacement of a target solely because the
   246 parameter types in the theorem are not as general as in the target,
   247 consider declaring a new locale with additional type constraints on
   248 the parameters (context element "constrains").
   249 
   250 - Discontinued "locale (open)".  INCOMPATIBILITY.
   251 
   252 - Locale interpretation commands no longer attempt to simplify goal.
   253 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   254 methods intro_locales and unfold_locales to clarify.
   255 
   256 - Locale interpretation commands no longer accept interpretation
   257 attributes.  INCOMPATIBILITY.
   258 
   259 * Class declaration: so-called "base sort" must not be given in import
   260 list any longer, but is inferred from the specification.  Particularly
   261 in HOL, write
   262 
   263     class foo = ...
   264 
   265 instead of
   266 
   267     class foo = type + ...
   268 
   269 * Class target: global versions of theorems stemming do not carry a
   270 parameter prefix any longer.  INCOMPATIBILITY.
   271 
   272 * Class 'instance' command no longer accepts attached definitions.
   273 INCOMPATIBILITY, use proper 'instantiation' target instead.
   274 
   275 * Recovered hiding of consts, which was accidentally broken in
   276 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   277 makes c inaccessible; consider using ``hide (open) const c'' instead.
   278 
   279 * Slightly more coherent Pure syntax, with updated documentation in
   280 isar-ref manual.  Removed locales meta_term_syntax and
   281 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   282 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   283 directly in regular applications.
   284 
   285 * There is a new syntactic category "float_const" for signed decimal
   286 fractions (e.g. 123.45 or -123.45).
   287 
   288 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   289 interface with 'setup' command instead.
   290 
   291 * Command 'local_setup' is similar to 'setup', but operates on a local
   292 theory context.
   293 
   294 * The 'axiomatization' command now only works within a global theory
   295 context.  INCOMPATIBILITY.
   296 
   297 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   298 hypotheses.  Sorts required in the course of reasoning need to be
   299 covered by the constraints in the initial statement, completed by the
   300 type instance information of the background theory.  Non-trivial sort
   301 hypotheses, which rarely occur in practice, may be specified via
   302 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   303 
   304   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   305 
   306 The result contains an implicit sort hypotheses as before --
   307 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   308 normalization.
   309 
   310 * Generalized Isar history, with support for linear undo, direct state
   311 addressing etc.
   312 
   313 * Changed defaults for unify configuration options:
   314 
   315   unify_trace_bound = 50 (formerly 25)
   316   unify_search_bound = 60 (formerly 30)
   317 
   318 * Different bookkeeping for code equations (INCOMPATIBILITY):
   319 
   320   a) On theory merge, the last set of code equations for a particular
   321      constant is taken (in accordance with the policy applied by other
   322      parts of the code generator framework).
   323 
   324   b) Code equations stemming from explicit declarations (e.g. code
   325      attribute) gain priority over default code equations stemming
   326      from definition, primrec, fun etc.
   327 
   328 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   329 
   330 * Unified theorem tables for both code generators.  Thus [code
   331 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   332 
   333 * Command 'find_consts' searches for constants based on type and name
   334 patterns, e.g.
   335 
   336     find_consts "_ => bool"
   337 
   338 By default, matching is against subtypes, but it may be restricted to
   339 the whole type.  Searching by name is possible.  Multiple queries are
   340 conjunctive and queries may be negated by prefixing them with a
   341 hyphen:
   342 
   343     find_consts strict: "_ => bool" name: "Int" -"int => int"
   344 
   345 * New 'find_theorems' criterion "solves" matches theorems that
   346 directly solve the current goal (modulo higher-order unification).
   347 
   348 * Auto solve feature for main theorem statements: whenever a new goal
   349 is stated, "find_theorems solves" is called; any theorems that could
   350 solve the lemma directly are listed as part of the goal state.
   351 Cf. associated options in Proof General Isabelle settings menu,
   352 enabled by default, with reasonable timeout for pathological cases of
   353 higher-order unification.
   354 
   355 
   356 *** Document preparation ***
   357 
   358 * Antiquotation @{lemma} now imitates a regular terminal proof,
   359 demanding keyword 'by' and supporting the full method expression
   360 syntax just like the Isar command 'by'.
   361 
   362 
   363 *** HOL ***
   364 
   365 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   366 points Main and Complex_Main remain as before.
   367 
   368 * Logic image HOL-Plain provides a minimal HOL with the most important
   369 tools available (inductive, datatype, primrec, ...).  This facilitates
   370 experimentation and tool development.  Note that user applications
   371 (and library theories) should never refer to anything below theory
   372 Main, as before.
   373 
   374 * Logic image HOL-Main stops at theory Main, and thus facilitates
   375 experimentation due to shorter build times.
   376 
   377 * Logic image HOL-NSA contains theories of nonstandard analysis which
   378 were previously part of former HOL-Complex.  Entry point Hyperreal
   379 remains valid, but theories formerly using Complex_Main should now use
   380 new entry point Hypercomplex.
   381 
   382 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   383 Posix processes.  Avoids potentially expensive forking of the ML
   384 process.  New thread-based implementation also works on non-Unix
   385 platforms (Cygwin).  Provers are no longer hardwired, but defined
   386 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   387 commands are covered in the isar-ref manual.
   388 
   389 * Wrapper scripts for remote SystemOnTPTP service allows to use
   390 sledgehammer without local ATP installation (Vampire etc.). Other
   391 provers may be included via suitable ML wrappers, see also
   392 src/HOL/ATP_Linkup.thy.
   393 
   394 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   395 menu.
   396 
   397 * The metis method no longer fails because the theorem is too trivial
   398 (contains the empty clause).
   399 
   400 * The metis method now fails in the usual manner, rather than raising
   401 an exception, if it determines that it cannot prove the theorem.
   402 
   403 * Method "coherent" implements a prover for coherent logic (see also
   404 src/Tools/coherent.ML).
   405 
   406 * Constants "undefined" and "default" replace "arbitrary".  Usually
   407 "undefined" is the right choice to replace "arbitrary", though
   408 logically there is no difference.  INCOMPATIBILITY.
   409 
   410 * Command "value" now integrates different evaluation mechanisms.  The
   411 result of the first successful evaluation mechanism is printed.  In
   412 square brackets a particular named evaluation mechanisms may be
   413 specified (currently, [SML], [code] or [nbe]).  See further
   414 src/HOL/ex/Eval_Examples.thy.
   415 
   416 * Normalization by evaluation now allows non-leftlinear equations.
   417 Declare with attribute [code nbe].
   418 
   419 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   420 as the structured Isar versions "cases" and "induct", cf. the
   421 corresponding "cases" and "induct" attributes.  Mutual induction rules
   422 are now presented as a list of individual projections
   423 (e.g. foo_bar.inducts for types foo and bar); the old format with
   424 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   425 rare situations a different rule is selected --- notably nested tuple
   426 elimination instead of former prod.exhaust: use explicit (case_tac t
   427 rule: prod.exhaust) here.
   428 
   429 * Attributes "cases", "induct", "coinduct" support "del" option.
   430 
   431 * Removed fact "case_split_thm", which duplicates "case_split".
   432 
   433 * The option datatype has been moved to a new theory Option.  Renamed
   434 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   435 
   436 * New predicate "strict_mono" classifies strict functions on partial
   437 orders.  With strict functions on linear orders, reasoning about
   438 (in)equalities is facilitated by theorems "strict_mono_eq",
   439 "strict_mono_less_eq" and "strict_mono_less".
   440 
   441 * Some set operations are now proper qualified constants with
   442 authentic syntax.  INCOMPATIBILITY:
   443 
   444     op Int ~>   Set.Int
   445     op Un ~>    Set.Un
   446     INTER ~>    Set.INTER
   447     UNION ~>    Set.UNION
   448     Inter ~>    Set.Inter
   449     Union ~>    Set.Union
   450     {} ~>       Set.empty
   451     UNIV ~>     Set.UNIV
   452 
   453 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   454 theory Set.
   455 
   456 * Auxiliary class "itself" has disappeared -- classes without any
   457 parameter are treated as expected by the 'class' command.
   458 
   459 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   460 
   461 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   462 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   463 
   464 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   465 method "approximation".  It proves formulas on real values by using
   466 interval arithmetic.  In the formulas are also the transcendental
   467 functions sin, cos, tan, atan, ln, exp and the constant pi are
   468 allowed. For examples see
   469 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   470 
   471 * Theory "Reflection" now resides in HOL/Library.
   472 
   473 * Entry point to Word library now simply named "Word".
   474 INCOMPATIBILITY.
   475 
   476 * Made source layout more coherent with logical distribution
   477 structure:
   478 
   479     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   480     src/HOL/Library/Code_Message.thy ~> src/HOL/
   481     src/HOL/Library/GCD.thy ~> src/HOL/
   482     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   483     src/HOL/Library/Parity.thy ~> src/HOL/
   484     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   485     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   486     src/HOL/Real/Lubs.thy ~> src/HOL/
   487     src/HOL/Real/PReal.thy ~> src/HOL/
   488     src/HOL/Real/Rational.thy ~> src/HOL/
   489     src/HOL/Real/RComplete.thy ~> src/HOL/
   490     src/HOL/Real/RealDef.thy ~> src/HOL/
   491     src/HOL/Real/RealPow.thy ~> src/HOL/
   492     src/HOL/Real/Real.thy ~> src/HOL/
   493     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   494     src/HOL/Complex/Complex.thy ~> src/HOL/
   495     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   496     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   497     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   498     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   499     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   500     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   501     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   502     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   503     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   504     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   505     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   506     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   507     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   508     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   509     src/HOL/Real/Float ~> src/HOL/Library/
   510     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   511     src/HOL/Real/RealVector.thy ~> src/HOL/
   512 
   513     src/HOL/arith_data.ML ~> src/HOL/Tools
   514     src/HOL/hologic.ML ~> src/HOL/Tools
   515     src/HOL/simpdata.ML ~> src/HOL/Tools
   516     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   517     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   518     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   519     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   520     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   521     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   522     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   523 
   524     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   525     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   526     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   527     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   528     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   529     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   530 
   531 * If methods "eval" and "evaluation" encounter a structured proof
   532 state with !!/==>, only the conclusion is evaluated to True (if
   533 possible), avoiding strange error messages.
   534 
   535 * Method "sizechange" automates termination proofs using (a
   536 modification of) the size-change principle.  Requires SAT solver.  See
   537 src/HOL/ex/Termination.thy for examples.
   538 
   539 * Simplifier: simproc for let expressions now unfolds if bound
   540 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   541 
   542 * Method "arith": Linear arithmetic now ignores all inequalities when
   543 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   544 
   545 * New attribute "arith" for facts that should always be used
   546 automatically by arithmetic. It is intended to be used locally in
   547 proofs, e.g.
   548 
   549   assumes [arith]: "x > 0"
   550 
   551 Global usage is discouraged because of possible performance impact.
   552 
   553 * New classes "top" and "bot" with corresponding operations "top" and
   554 "bot" in theory Orderings; instantiation of class "complete_lattice"
   555 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   556 
   557 * Changed definition lemma "less_fun_def" in order to provide an
   558 instance for preorders on functions; use lemma "less_le" instead.
   559 INCOMPATIBILITY.
   560 
   561 * Theory Orderings: class "wellorder" moved here, with explicit
   562 induction rule "less_induct" as assumption.  For instantiation of
   563 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   564 INCOMPATIBILITY.
   565 
   566 * Theory Orderings: added class "preorder" as superclass of "order".
   567 INCOMPATIBILITY: Instantiation proofs for order, linorder
   568 etc. slightly changed.  Some theorems named order_class.* now named
   569 preorder_class.*.
   570 
   571 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   572 "diag" to "Id_on".
   573 
   574 * Theory Finite_Set: added a new fold combinator of type
   575 
   576   ('a => 'b => 'b) => 'b => 'a set => 'b
   577 
   578 Occasionally this is more convenient than the old fold combinator
   579 which is now defined in terms of the new one and renamed to
   580 fold_image.
   581 
   582 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   583 and "ring_simps" have been replaced by "algebra_simps" (which can be
   584 extended with further lemmas!).  At the moment both still exist but
   585 the former will disappear at some point.
   586 
   587 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   588 class recpower.  Type-specific simp rules for various recpower types
   589 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   590 
   591 rat_power_0    -> power_0
   592 rat_power_Suc  -> power_Suc
   593 realpow_0      -> power_0
   594 realpow_Suc    -> power_Suc
   595 complexpow_0   -> power_0
   596 complexpow_Suc -> power_Suc
   597 power_poly_0   -> power_0
   598 power_poly_Suc -> power_Suc
   599 
   600 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   601 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   602 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   603 of lemmas from Divides has been generalized from nat to class
   604 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   605 renames resulting from duplicate elimination:
   606 
   607     dvd_def_mod ~>          dvd_eq_mod_eq_0
   608     zero_dvd_iff ~>         dvd_0_left_iff
   609     dvd_0 ~>                dvd_0_right
   610     DIVISION_BY_ZERO_DIV ~> div_by_0
   611     DIVISION_BY_ZERO_MOD ~> mod_by_0
   612     mult_div ~>             div_mult_self2_is_id
   613     mult_mod ~>             mod_mult_self2_is_0
   614 
   615 * Theory IntDiv: removed many lemmas that are instances of class-based
   616 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   617 rename old lemmas as follows:
   618 
   619 dvd_diff               -> nat_dvd_diff
   620 dvd_zminus_iff         -> dvd_minus_iff
   621 mod_add1_eq            -> mod_add_eq
   622 mod_mult1_eq           -> mod_mult_right_eq
   623 mod_mult1_eq'          -> mod_mult_left_eq
   624 mod_mult_distrib_mod   -> mod_mult_eq
   625 nat_mod_add_left_eq    -> mod_add_left_eq
   626 nat_mod_add_right_eq   -> mod_add_right_eq
   627 nat_mod_div_trivial    -> mod_div_trivial
   628 nat_mod_mod_trivial    -> mod_mod_trivial
   629 zdiv_zadd_self1        -> div_add_self1
   630 zdiv_zadd_self2        -> div_add_self2
   631 zdiv_zmult_self1       -> div_mult_self2_is_id
   632 zdiv_zmult_self2       -> div_mult_self1_is_id
   633 zdvd_triv_left         -> dvd_triv_left
   634 zdvd_triv_right        -> dvd_triv_right
   635 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   636 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   637 zmod_zadd_left_eq      -> mod_add_left_eq
   638 zmod_zadd_right_eq     -> mod_add_right_eq
   639 zmod_zadd_self1        -> mod_add_self1
   640 zmod_zadd_self2        -> mod_add_self2
   641 zmod_zadd1_eq          -> mod_add_eq
   642 zmod_zdiff1_eq         -> mod_diff_eq
   643 zmod_zdvd_zmod         -> mod_mod_cancel
   644 zmod_zmod_cancel       -> mod_mod_cancel
   645 zmod_zmult_self1       -> mod_mult_self2_is_0
   646 zmod_zmult_self2       -> mod_mult_self1_is_0
   647 zmod_1                 -> mod_by_1
   648 zdiv_1                 -> div_by_1
   649 zdvd_abs1              -> abs_dvd_iff
   650 zdvd_abs2              -> dvd_abs_iff
   651 zdvd_refl              -> dvd_refl
   652 zdvd_trans             -> dvd_trans
   653 zdvd_zadd              -> dvd_add
   654 zdvd_zdiff             -> dvd_diff
   655 zdvd_zminus_iff        -> dvd_minus_iff
   656 zdvd_zminus2_iff       -> minus_dvd_iff
   657 zdvd_zmultD            -> dvd_mult_right
   658 zdvd_zmultD2           -> dvd_mult_left
   659 zdvd_zmult_mono        -> mult_dvd_mono
   660 zdvd_0_right           -> dvd_0_right
   661 zdvd_0_left            -> dvd_0_left_iff
   662 zdvd_1_left            -> one_dvd
   663 zminus_dvd_iff         -> minus_dvd_iff
   664 
   665 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   666 
   667 * The real numbers offer decimal input syntax: 12.34 is translated
   668 into 1234/10^2. This translation is not reversed upon output.
   669 
   670 * Theory Library/Polynomial defines an abstract type 'a poly of
   671 univariate polynomials with coefficients of type 'a.  In addition to
   672 the standard ring operations, it also supports div and mod.  Code
   673 generation is also supported, using list-style constructors.
   674 
   675 * Theory Library/Inner_Product defines a class of real_inner for real
   676 inner product spaces, with an overloaded operation inner :: 'a => 'a
   677 => real.  Class real_inner is a subclass of real_normed_vector from
   678 theory RealVector.
   679 
   680 * Theory Library/Product_Vector provides instances for the product
   681 type 'a * 'b of several classes from RealVector and Inner_Product.
   682 Definitions of addition, subtraction, scalar multiplication, norms,
   683 and inner products are included.
   684 
   685 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   686 addition to the field operations, numerals and case syntax are also
   687 supported.
   688 
   689 * Theory Library/Diagonalize provides constructive version of Cantor's
   690 first diagonalization argument.
   691 
   692 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   693 zlcm (for int); carried together from various gcd/lcm developements in
   694 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   695 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   696 may recover tupled syntax as follows:
   697 
   698     hide (open) const gcd
   699     abbreviation gcd where
   700       "gcd == (%(a, b). GCD.gcd a b)"
   701     notation (output)
   702       GCD.gcd ("gcd '(_, _')")
   703 
   704 The same works for lcm, zgcd, zlcm.
   705 
   706 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   707 instantiations for algebraic structures.  Removed some duplicate
   708 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   709 
   710 * ML antiquotation @{code} takes a constant as argument and generates
   711 corresponding code in background and inserts name of the corresponding
   712 resulting ML value/function/datatype constructor binding in place.
   713 All occurrences of @{code} with a single ML block are generated
   714 simultaneously.  Provides a generic and safe interface for
   715 instrumentalizing code generation.  See
   716 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   717 In future you ought to refrain from ad-hoc compiling generated SML
   718 code on the ML toplevel.  Note that (for technical reasons) @{code}
   719 cannot refer to constants for which user-defined serializations are
   720 set.  Refer to the corresponding ML counterpart directly in that
   721 cases.
   722 
   723 * Command 'rep_datatype': instead of theorem names the command now
   724 takes a list of terms denoting the constructors of the type to be
   725 represented as datatype.  The characteristic theorems have to be
   726 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   727 have disappeared in favour of existing ones:
   728 
   729     unit_induct                 ~> unit.induct
   730     prod_induct                 ~> prod.induct
   731     sum_induct                  ~> sum.induct
   732     Suc_Suc_eq                  ~> nat.inject
   733     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   734 
   735 
   736 *** HOL-Algebra ***
   737 
   738 * New locales for orders and lattices where the equivalence relation
   739 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   740 locales use a record structure with field eq for the equivalence.
   741 
   742 * New theory of factorial domains.
   743 
   744 * Units_l_inv and Units_r_inv are now simp rules by default.
   745 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   746 and/or r_inv will now also require deletion of these lemmas.
   747 
   748 * Renamed the following theorems, INCOMPATIBILITY:
   749 
   750 UpperD ~> Upper_memD
   751 LowerD ~> Lower_memD
   752 least_carrier ~> least_closed
   753 greatest_carrier ~> greatest_closed
   754 greatest_Lower_above ~> greatest_Lower_below
   755 one_zero ~> carrier_one_zero
   756 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   757 
   758 
   759 *** HOL-Nominal ***
   760 
   761 * Nominal datatypes can now contain type-variables.
   762 
   763 * Commands 'nominal_inductive' and 'equivariance' work with local
   764 theory targets.
   765 
   766 * Nominal primrec can now works with local theory targets and its
   767 specification syntax now conforms to the general format as seen in
   768 'inductive' etc.
   769 
   770 * Method "perm_simp" honours the standard simplifier attributes
   771 (no_asm), (no_asm_use) etc.
   772 
   773 * The new predicate #* is defined like freshness, except that on the
   774 left hand side can be a set or list of atoms.
   775 
   776 * Experimental command 'nominal_inductive2' derives strong induction
   777 principles for inductive definitions.  In contrast to
   778 'nominal_inductive', which can only deal with a fixed number of
   779 binders, it can deal with arbitrary expressions standing for sets of
   780 atoms to be avoided.  The only inductive definition we have at the
   781 moment that needs this generalisation is the typing rule for Lets in
   782 the algorithm W:
   783 
   784  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   785  -----------------------------------------------------------------
   786          Gamma |- Let x be t1 in t2 : T2
   787 
   788 In this rule one wants to avoid all the binders that are introduced by
   789 "close Gamma T1".  We are looking for other examples where this
   790 feature might be useful.  Please let us know.
   791 
   792 
   793 *** HOLCF ***
   794 
   795 * Reimplemented the simplification procedure for proving continuity
   796 subgoals.  The new simproc is extensible; users can declare additional
   797 continuity introduction rules with the attribute [cont2cont].
   798 
   799 * The continuity simproc now uses a different introduction rule for
   800 solving continuity subgoals on terms with lambda abstractions.  In
   801 some rare cases the new simproc may fail to solve subgoals that the
   802 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   803 Potential INCOMPATIBILITY.
   804 
   805 * Command 'fixrec': specification syntax now conforms to the general
   806 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   807 examples.  INCOMPATIBILITY.
   808 
   809 
   810 *** ZF ***
   811 
   812 * Proof of Zorn's Lemma for partial orders.
   813 
   814 
   815 *** ML ***
   816 
   817 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   818 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   819 depends on multithreading, so timouts will not work before Poly/ML
   820 5.2.1!
   821 
   822 * High-level support for concurrent ML programming, see
   823 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   824 particularly convenient to organize independent functional
   825 computations.  The concept of "synchronized variables" provides a
   826 higher-order interface for components with shared state, avoiding the
   827 delicate details of mutexes and condition variables.  (Requires
   828 Poly/ML 5.2.1 or later.)
   829 
   830 * ML bindings produced via Isar commands are stored within the Isar
   831 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   832 become thread-safe and work with undo as expected (concerning
   833 top-level bindings, not side-effects on global references).
   834 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   835 compiler at runtime; really global bindings need to be given outside a
   836 theory.  (Requires Poly/ML 5.2 or later.)
   837 
   838 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   839 context.  Top-level ML bindings are stored within the proof context in
   840 a purely sequential fashion, disregarding the nested proof structure.
   841 ML bindings introduced by 'ML_prf' are discarded at the end of the
   842 proof.  (Requires Poly/ML 5.2 or later.)
   843 
   844 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   845 and Method.setup, as well as Isar commands 'attribute_setup' and
   846 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   847 existing code accordingly, or use plain 'setup' together with old
   848 Method.add_method.
   849 
   850 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   851 to 'a -> thm, while results are always tagged with an authentic oracle
   852 name.  The Isar command 'oracle' is now polymorphic, no argument type
   853 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   854 accordingly.  Note that extra performance may be gained by producing
   855 the cterm carefully, avoiding slow Thm.cterm_of.
   856 
   857 * Simplified interface for defining document antiquotations via
   858 ThyOutput.antiquotation, ThyOutput.output, and optionally
   859 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   860 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   861 examples.
   862 
   863 * More systematic treatment of long names, abstract name bindings, and
   864 name space operations.  Basic operations on qualified names have been
   865 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   866 Long_Name.append.  Old type bstring has been mostly replaced by
   867 abstract type binding (see structure Binding), which supports precise
   868 qualification by packages and local theory targets, as well as proper
   869 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   870 bstring values into Binding.name, or better pass through abstract
   871 bindings everywhere.  See further src/Pure/General/long_name.ML,
   872 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   873 
   874 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   875 LocalTheory.note etc.) now refer to the *full* internal name, not the
   876 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   877 
   878 * Disposed old type and term read functions (Sign.read_def_typ,
   879 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   880 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   881 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   882 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   883 resort for legacy applications.
   884 
   885 * Disposed old declarations, tactics, tactic combinators that refer to
   886 the simpset or claset of an implicit theory (such as Addsimps,
   887 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   888 embedded ML text, or local_simpset_of with a proper context passed as
   889 explicit runtime argument.
   890 
   891 * Rules and tactics that read instantiations (read_instantiate,
   892 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   893 context, which is required for parsing and type-checking.  Moreover,
   894 the variables are specified as plain indexnames, not string encodings
   895 thereof.  INCOMPATIBILITY.
   896 
   897 * Generic Toplevel.add_hook interface allows to analyze the result of
   898 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   899 for theorem dependency output of transactions resulting in a new
   900 theory state.
   901 
   902 * ML antiquotations: block-structured compilation context indicated by
   903 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   904 
   905   @{binding name}                         - basic name binding
   906   @{let ?pat = term}                      - term abbreviation (HO matching)
   907   @{note name = fact}                     - fact abbreviation
   908   @{thm fact}                             - singleton fact (with attributes)
   909   @{thms fact}                            - general fact (with attributes)
   910   @{lemma prop by method}                 - singleton goal
   911   @{lemma prop by meth1 meth2}            - singleton goal
   912   @{lemma prop1 ... propN by method}      - general goal
   913   @{lemma prop1 ... propN by meth1 meth2} - general goal
   914   @{lemma (open) ...}                     - open derivation
   915 
   916 
   917 *** System ***
   918 
   919 * The Isabelle "emacs" tool provides a specific interface to invoke
   920 Proof General / Emacs, with more explicit failure if that is not
   921 installed (the old isabelle-interface script silently falls back on
   922 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   923 installation location of the Proof General distribution.
   924 
   925 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   926 the Isabelle process into a JVM/Scala application.  See
   927 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   928 process wrapper has been discontinued.)
   929 
   930 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   931 
   932 * Various status messages (with exact source position information) are
   933 emitted, if proper markup print mode is enabled.  This allows
   934 user-interface components to provide detailed feedback on internal
   935 prover operations.
   936 
   937 
   938 
   939 New in Isabelle2008 (June 2008)
   940 -------------------------------
   941 
   942 *** General ***
   943 
   944 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   945 and updated, with formally checked references as hyperlinks.
   946 
   947 * Theory loader: use_thy (and similar operations) no longer set the
   948 implicit ML context, which was occasionally hard to predict and in
   949 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   950 provides a proper context already.
   951 
   952 * Theory loader: old-style ML proof scripts being *attached* to a thy
   953 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   954 'use' within a theory file will do the job.
   955 
   956 * Name space merge now observes canonical order, i.e. the second space
   957 is inserted into the first one, while existing entries in the first
   958 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   959 swap theory imports.
   960 
   961 * Syntax: symbol \<chi> is now considered a letter.  Potential
   962 INCOMPATIBILITY in identifier syntax etc.
   963 
   964 * Outer syntax: string tokens no longer admit escaped white space,
   965 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   966 white space without escapes.
   967 
   968 * Outer syntax: string tokens may contain arbitrary character codes
   969 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   970 "foo_bar".
   971 
   972 
   973 *** Pure ***
   974 
   975 * Context-dependent token translations.  Default setup reverts locally
   976 fixed variables, and adds hilite markup for undeclared frees.
   977 
   978 * Unused theorems can be found using the new command 'unused_thms'.
   979 There are three ways of invoking it:
   980 
   981 (1) unused_thms
   982      Only finds unused theorems in the current theory.
   983 
   984 (2) unused_thms thy_1 ... thy_n -
   985      Finds unused theorems in the current theory and all of its ancestors,
   986      excluding the theories thy_1 ... thy_n and all of their ancestors.
   987 
   988 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   989      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   990      their ancestors, excluding the theories thy_1 ... thy_n and all of
   991      their ancestors.
   992 
   993 In order to increase the readability of the list produced by
   994 unused_thms, theorems that have been created by a particular instance
   995 of a theory command such as 'inductive' or 'function' are considered
   996 to belong to the same "group", meaning that if at least one theorem in
   997 this group is used, the other theorems in the same group are no longer
   998 reported as unused.  Moreover, if all theorems in the group are
   999 unused, only one theorem in the group is displayed.
  1000 
  1001 Note that proof objects have to be switched on in order for
  1002 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1003 usually the case when using Proof General with the default settings).
  1004 
  1005 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1006 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1007 duplicate fact bindings, or even accidental fact duplications.  Note
  1008 that tools may maintain dynamically scoped facts systematically, using
  1009 PureThy.add_thms_dynamic.
  1010 
  1011 * Command 'hide' now allows to hide from "fact" name space as well.
  1012 
  1013 * Eliminated destructive theorem database, simpset, claset, and
  1014 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1015 update of theories within ML code.
  1016 
  1017 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1018 INCOMPATIBILITY, object-logics depending on former Pure require
  1019 additional setup PureThy.old_appl_syntax_setup; object-logics
  1020 depending on former CPure need to refer to Pure.
  1021 
  1022 * Commands 'use' and 'ML' are now purely functional, operating on
  1023 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1024 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1025 INCOMPATIBILITY.
  1026 
  1027 * Command 'setup': discontinued implicit version with ML reference.
  1028 
  1029 * Instantiation target allows for simultaneous specification of class
  1030 instance operations together with an instantiation proof.
  1031 Type-checking phase allows to refer to class operations uniformly.
  1032 See src/HOL/Complex/Complex.thy for an Isar example and
  1033 src/HOL/Library/Eval.thy for an ML example.
  1034 
  1035 * Indexing of literal facts: be more serious about including only
  1036 facts from the visible specification/proof context, but not the
  1037 background context (locale etc.).  Affects `prop` notation and method
  1038 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1039 situations.
  1040 
  1041 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1042 "(open)" option, which used to expose internal bound variables to the
  1043 proof text.
  1044 
  1045 * Isar statements: removed obsolete case "rule_context".
  1046 INCOMPATIBILITY, better use explicit fixes/assumes.
  1047 
  1048 * Locale proofs: default proof step now includes 'unfold_locales';
  1049 hence 'proof' without argument may be used to unfold locale
  1050 predicates.
  1051 
  1052 
  1053 *** Document preparation ***
  1054 
  1055 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1056 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1057 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1058 spot); renamed link color from "darkblue" to "linkcolor" (default
  1059 value unchanged, can be redefined via \definecolor); no longer sets
  1060 "a4paper" option (unnecessary or even intrusive).
  1061 
  1062 * Antiquotation @{lemma A method} proves proposition A by the given
  1063 method (either a method name or a method name plus (optional) method
  1064 arguments in parentheses) and prints A just like @{prop A}.
  1065 
  1066 
  1067 *** HOL ***
  1068 
  1069 * New primrec package.  Specification syntax conforms in style to
  1070 definition/function/....  No separate induction rule is provided.  The
  1071 "primrec" command distinguishes old-style and new-style specifications
  1072 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1073 When adjusting theories, beware: constants stemming from new-style
  1074 primrec specifications have authentic syntax.
  1075 
  1076 * Metis prover is now an order of magnitude faster, and also works
  1077 with multithreading.
  1078 
  1079 * Metis: the maximum number of clauses that can be produced from a
  1080 theorem is now given by the attribute max_clauses.  Theorems that
  1081 exceed this number are ignored, with a warning printed.
  1082 
  1083 * Sledgehammer no longer produces structured proofs by default. To
  1084 enable, declare [[sledgehammer_full = true]].  Attributes
  1085 reconstruction_modulus, reconstruction_sorts renamed
  1086 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1087 
  1088 * Method "induct_scheme" derives user-specified induction rules
  1089 from well-founded induction and completeness of patterns. This factors
  1090 out some operations that are done internally by the function package
  1091 and makes them available separately.  See
  1092 src/HOL/ex/Induction_Scheme.thy for examples.
  1093 
  1094 * More flexible generation of measure functions for termination
  1095 proofs: Measure functions can be declared by proving a rule of the
  1096 form "is_measure f" and giving it the [measure_function] attribute.
  1097 The "is_measure" predicate is logically meaningless (always true), and
  1098 just guides the heuristic.  To find suitable measure functions, the
  1099 termination prover sets up the goal "is_measure ?f" of the appropriate
  1100 type and generates all solutions by prolog-style backwards proof using
  1101 the declared rules.
  1102 
  1103 This setup also deals with rules like 
  1104 
  1105   "is_measure f ==> is_measure (list_size f)"
  1106 
  1107 which accommodates nested datatypes that recurse through lists.
  1108 Similar rules are predeclared for products and option types.
  1109 
  1110 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1111 
  1112   INCOMPATIBILITIES:
  1113 
  1114   - Definitions of overloaded constants on sets have to be replaced by
  1115     definitions on => and bool.
  1116 
  1117   - Some definitions of overloaded operators on sets can now be proved
  1118     using the definitions of the operators on => and bool.  Therefore,
  1119     the following theorems have been renamed:
  1120 
  1121       subset_def   -> subset_eq
  1122       psubset_def  -> psubset_eq
  1123       set_diff_def -> set_diff_eq
  1124       Compl_def    -> Compl_eq
  1125       Sup_set_def  -> Sup_set_eq
  1126       Inf_set_def  -> Inf_set_eq
  1127       sup_set_def  -> sup_set_eq
  1128       inf_set_def  -> inf_set_eq
  1129 
  1130   - Due to the incompleteness of the HO unification algorithm, some
  1131     rules such as subst may require manual instantiation, if some of
  1132     the unknowns in the rule is a set.
  1133 
  1134   - Higher order unification and forward proofs:
  1135     The proof pattern
  1136 
  1137       have "P (S::'a set)" <...>
  1138       then have "EX S. P S" ..
  1139 
  1140     no longer works (due to the incompleteness of the HO unification
  1141     algorithm) and must be replaced by the pattern
  1142 
  1143       have "EX S. P S"
  1144       proof
  1145         show "P S" <...>
  1146       qed
  1147 
  1148   - Calculational reasoning with subst (or similar rules):
  1149     The proof pattern
  1150 
  1151       have "P (S::'a set)" <...>
  1152       also have "S = T" <...>
  1153       finally have "P T" .
  1154 
  1155     no longer works (for similar reasons as the previous example) and
  1156     must be replaced by something like
  1157 
  1158       have "P (S::'a set)" <...>
  1159       moreover have "S = T" <...>
  1160       ultimately have "P T" by simp
  1161 
  1162   - Tactics or packages written in ML code:
  1163     Code performing pattern matching on types via
  1164 
  1165       Type ("set", [T]) => ...
  1166 
  1167     must be rewritten. Moreover, functions like strip_type or
  1168     binder_types no longer return the right value when applied to a
  1169     type of the form
  1170 
  1171       T1 => ... => Tn => U => bool
  1172 
  1173     rather than
  1174 
  1175       T1 => ... => Tn => U set
  1176 
  1177 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1178 Wellfounded_Relations to theory Wellfounded.
  1179 
  1180 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1181 
  1182 * Class finite no longer treats UNIV as class parameter.  Use class
  1183 enum from theory Library/Enum instead to achieve a similar effect.
  1184 INCOMPATIBILITY.
  1185 
  1186 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1187 and "Cons".  INCOMPATIBILITY.
  1188 
  1189 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1190 Potential INCOMPATIBILITY.
  1191 
  1192 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1193 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1194 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1195 
  1196 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1197 the same name in theory Orderings:
  1198 
  1199   less_trans
  1200   less_linear
  1201   le_imp_less_or_eq
  1202   le_less_trans
  1203   less_le_trans
  1204   less_not_sym
  1205   less_asym
  1206 
  1207 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1208 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1209 and different variable names.
  1210 
  1211 * Library/Option_ord.thy: Canonical order on option type.
  1212 
  1213 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1214 finite maps.
  1215 
  1216 * Library/Countable.thy: Type class for countable types.
  1217 
  1218 * Theory Int: The representation of numerals has changed.  The infix
  1219 operator BIT and the bit datatype with constructors B0 and B1 have
  1220 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1221 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1222 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1223 accordingly.
  1224 
  1225 * Theory Nat: definition of <= and < on natural numbers no longer
  1226 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1227 le_def and less_def have disappeared.  Consider lemmas not_less
  1228 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1229 
  1230 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1231 (whose purpose mainly is for various fold_set functionals) have been
  1232 abandoned in favor of the existing algebraic classes
  1233 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1234 lower_semilattice (resp. upper_semilattice) and linorder.
  1235 INCOMPATIBILITY.
  1236 
  1237 * Theory Transitive_Closure: induct and cases rules now declare proper
  1238 case_names ("base" and "step").  INCOMPATIBILITY.
  1239 
  1240 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1241 lattices.  The form set-specific version is available as
  1242 Inductive.lfp_ordinal_induct_set.
  1243 
  1244 * Renamed theorems "power.simps" to "power_int.simps".
  1245 INCOMPATIBILITY.
  1246 
  1247 * Class semiring_div provides basic abstract properties of semirings
  1248 with division and modulo operations.  Subsumes former class dvd_mod.
  1249 
  1250 * Merged theories IntDef, Numeral and IntArith into unified theory
  1251 Int.  INCOMPATIBILITY.
  1252 
  1253 * Theory Library/Code_Index: type "index" now represents natural
  1254 numbers rather than integers.  INCOMPATIBILITY.
  1255 
  1256 * New class "uminus" with operation "uminus" (split of from class
  1257 "minus" which now only has operation "minus", binary).
  1258 INCOMPATIBILITY.
  1259 
  1260 * Constants "card", "internal_split", "option_map" now with authentic
  1261 syntax.  INCOMPATIBILITY.
  1262 
  1263 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1264 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1265 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1266 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1267 Sup_set_def, le_def, less_def, option_map_def now with object
  1268 equality.  INCOMPATIBILITY.
  1269 
  1270 * Records. Removed K_record, and replaced it by pure lambda term
  1271 %x. c. The simplifier setup is now more robust against eta expansion.
  1272 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1273 
  1274 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1275 
  1276 * Library/ListVector: new theory of arithmetic vector operations.
  1277 
  1278 * Library/Order_Relation: new theory of various orderings as sets of
  1279 pairs.  Defines preorders, partial orders, linear orders and
  1280 well-orders on sets and on types.
  1281 
  1282 
  1283 *** ZF ***
  1284 
  1285 * Renamed some theories to allow to loading both ZF and HOL in the
  1286 same session:
  1287 
  1288   Datatype  -> Datatype_ZF
  1289   Inductive -> Inductive_ZF
  1290   Int       -> Int_ZF
  1291   IntDiv    -> IntDiv_ZF
  1292   Nat       -> Nat_ZF
  1293   List      -> List_ZF
  1294   Main      -> Main_ZF
  1295 
  1296 INCOMPATIBILITY: ZF theories that import individual theories below
  1297 Main might need to be adapted.  Regular theory Main is still
  1298 available, as trivial extension of Main_ZF.
  1299 
  1300 
  1301 *** ML ***
  1302 
  1303 * ML within Isar: antiquotation @{const name} or @{const
  1304 name(typargs)} produces statically-checked Const term.
  1305 
  1306 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1307 (of the same name).  Removed obsolete print command.
  1308 
  1309 * Removed obsolete "use_legacy_bindings" function.
  1310 
  1311 * The ``print mode'' is now a thread-local value derived from a global
  1312 template (the former print_mode reference), thus access becomes
  1313 non-critical.  The global print_mode reference is for session
  1314 management only; user-code should use print_mode_value,
  1315 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1316 
  1317 * Functions system/system_out provide a robust way to invoke external
  1318 shell commands, with propagation of interrupts (requires Poly/ML
  1319 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1320 
  1321 
  1322 *** System ***
  1323 
  1324 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1325 in accordance with Proof General 3.7, which prefers GNU emacs.
  1326 
  1327 * isatool tty runs Isabelle process with plain tty interaction;
  1328 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1329 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1330 
  1331 * isatool browser now works with Cygwin as well, using general
  1332 "javapath" function defined in Isabelle process environment.
  1333 
  1334 * YXML notation provides a simple and efficient alternative to
  1335 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1336 isatool yxml as described in the Isabelle system manual.
  1337 
  1338 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1339 provides general wrapper for managing an Isabelle process in a robust
  1340 fashion, with ``cooked'' output from stdin/stderr.
  1341 
  1342 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1343 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1344 
  1345 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1346 way of changing the user's settings is via
  1347 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1348 script.
  1349 
  1350 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1351 cores of the underlying machine, which is a good starting point for
  1352 optimal performance tuning.  The corresponding usedir option -M allows
  1353 "max" as an alias for "0".  WARNING: does not work on certain versions
  1354 of Mac OS (with Poly/ML 5.1).
  1355 
  1356 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1357 adverse effect of Isabelle flooding interactive front-ends (notably
  1358 ProofGeneral / XEmacs).
  1359 
  1360 
  1361 
  1362 New in Isabelle2007 (November 2007)
  1363 -----------------------------------
  1364 
  1365 *** General ***
  1366 
  1367 * More uniform information about legacy features, notably a
  1368 warning/error of "Legacy feature: ...", depending on the state of the
  1369 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1370 legacy features will disappear eventually.
  1371 
  1372 * Theory syntax: the header format ``theory A = B + C:'' has been
  1373 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1374 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1375 
  1376 * Theory syntax: the old non-Isar theory file format has been
  1377 discontinued altogether.  Note that ML proof scripts may still be used
  1378 with Isar theories; migration is usually quite simple with the ML
  1379 function use_legacy_bindings.  INCOMPATIBILITY.
  1380 
  1381 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1382 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1383 quotes.
  1384 
  1385 * Theory loader: be more serious about observing the static theory
  1386 header specifications (including optional directories), but not the
  1387 accidental file locations of previously successful loads.  The strict
  1388 update policy of former update_thy is now already performed by
  1389 use_thy, so the former has been removed; use_thys updates several
  1390 theories simultaneously, just as 'imports' within a theory header
  1391 specification, but without merging the results.  Potential
  1392 INCOMPATIBILITY: may need to refine theory headers and commands
  1393 ROOT.ML which depend on load order.
  1394 
  1395 * Theory loader: optional support for content-based file
  1396 identification, instead of the traditional scheme of full physical
  1397 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1398 (cf. the system manual).  The new scheme allows to work with
  1399 non-finished theories in persistent session images, such that source
  1400 files may be moved later on without requiring reloads.
  1401 
  1402 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1403 file (with the same base name as the theory) are considered a legacy
  1404 feature, which will disappear eventually. Even now, the theory loader
  1405 no longer maintains dependencies on such files.
  1406 
  1407 * Syntax: the scope for resolving ambiguities via type-inference is
  1408 now limited to individual terms, instead of whole simultaneous
  1409 specifications as before. This greatly reduces the complexity of the
  1410 syntax module and improves flexibility by separating parsing and
  1411 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1412 'fixes' etc.) are required in rare situations.
  1413 
  1414 * Syntax: constants introduced by new-style packages ('definition',
  1415 'abbreviation' etc.) are passed through the syntax module in
  1416 ``authentic mode''. This means that associated mixfix annotations
  1417 really stick to such constants, independently of potential name space
  1418 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1419 trees are represented slightly differently, may need to adapt syntax
  1420 translations accordingly. Use CONST marker in 'translations' and
  1421 @{const_syntax} antiquotation in 'parse_translation' etc.
  1422 
  1423 * Legacy goal package: reduced interface to the bare minimum required
  1424 to keep existing proof scripts running.  Most other user-level
  1425 functions are now part of the OldGoals structure, which is *not* open
  1426 by default (consider isatool expandshort before open OldGoals).
  1427 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1428 these tend to cause confusion about the actual goal (!) context being
  1429 used here, which is not necessarily the same as the_context().
  1430 
  1431 * Command 'find_theorems': supports "*" wild-card in "name:"
  1432 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1433 support a specific search form (see ProofGeneral/CHANGES).
  1434 
  1435 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1436 by default, which means that "prems" (and also "fixed variables") are
  1437 suppressed from proof state output.  Note that the ProofGeneral
  1438 settings mechanism allows to change and save options persistently, but
  1439 older versions of Isabelle will fail to start up if a negative prems
  1440 limit is imposed.
  1441 
  1442 * Local theory targets may be specified by non-nested blocks of
  1443 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1444 contain definitions, theorems etc., including any derived mechanism
  1445 that has been implemented on top of these primitives.  This concept
  1446 generalizes the existing ``theorem (in ...)'' towards more versatility
  1447 and scalability.
  1448 
  1449 * Proof General interface: proper undo of final 'end' command;
  1450 discontinued Isabelle/classic mode (ML proof scripts).
  1451 
  1452 
  1453 *** Document preparation ***
  1454 
  1455 * Added antiquotation @{theory name} which prints the given name,
  1456 after checking that it refers to a valid ancestor theory in the
  1457 current context.
  1458 
  1459 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1460 check the given source text as ML type/structure, printing verbatim.
  1461 
  1462 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1463 "c args == rhs" given in the current context.  (Any number of
  1464 arguments may be given on the LHS.)
  1465 
  1466 
  1467 *** Pure ***
  1468 
  1469 * The 'class' package offers a combination of axclass and locale to
  1470 achieve Haskell-like type classes in Isabelle.  Definitions and
  1471 theorems within a class context produce both relative results (with
  1472 implicit parameters according to the locale context), and polymorphic
  1473 constants with qualified polymorphism (according to the class
  1474 context).  Within the body context of a 'class' target, a separate
  1475 syntax layer ("user space type system") takes care of converting
  1476 between global polymorphic consts and internal locale representation.
  1477 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1478 "isatool doc classes" provides a tutorial.
  1479 
  1480 * Generic code generator framework allows to generate executable
  1481 code for ML and Haskell (including Isabelle classes).  A short usage
  1482 sketch:
  1483 
  1484     internal compilation:
  1485         export_code <list of constants (term syntax)> in SML
  1486     writing SML code to a file:
  1487         export_code <list of constants (term syntax)> in SML <filename>
  1488     writing OCaml code to a file:
  1489         export_code <list of constants (term syntax)> in OCaml <filename>
  1490     writing Haskell code to a bunch of files:
  1491         export_code <list of constants (term syntax)> in Haskell <filename>
  1492 
  1493     evaluating closed propositions to True/False using code generation:
  1494         method ``eval''
  1495 
  1496 Reasonable default setup of framework in HOL.
  1497 
  1498 Theorem attributs for selecting and transforming function equations theorems:
  1499 
  1500     [code fun]:        select a theorem as function equation for a specific constant
  1501     [code fun del]:    deselect a theorem as function equation for a specific constant
  1502     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1503     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1504 
  1505 User-defined serializations (target in {SML, OCaml, Haskell}):
  1506 
  1507     code_const <and-list of constants (term syntax)>
  1508       {(target) <and-list of const target syntax>}+
  1509 
  1510     code_type <and-list of type constructors>
  1511       {(target) <and-list of type target syntax>}+
  1512 
  1513     code_instance <and-list of instances>
  1514       {(target)}+
  1515         where instance ::= <type constructor> :: <class>
  1516 
  1517     code_class <and_list of classes>
  1518       {(target) <and-list of class target syntax>}+
  1519         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1520 
  1521 code_instance and code_class only are effective to target Haskell.
  1522 
  1523 For example usage see src/HOL/ex/Codegenerator.thy and
  1524 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1525 generation from Isabelle/HOL theories is available via "isatool doc
  1526 codegen".
  1527 
  1528 * Code generator: consts in 'consts_code' Isar commands are now
  1529 referred to by usual term syntax (including optional type
  1530 annotations).
  1531 
  1532 * Command 'no_translations' removes translation rules from theory
  1533 syntax.
  1534 
  1535 * Overloaded definitions are now actually checked for acyclic
  1536 dependencies.  The overloading scheme is slightly more general than
  1537 that of Haskell98, although Isabelle does not demand an exact
  1538 correspondence to type class and instance declarations.
  1539 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1540 exotic versions of overloading -- at the discretion of the user!
  1541 
  1542 Polymorphic constants are represented via type arguments, i.e. the
  1543 instantiation that matches an instance against the most general
  1544 declaration given in the signature.  For example, with the declaration
  1545 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1546 as c(nat).  Overloading is essentially simultaneous structural
  1547 recursion over such type arguments.  Incomplete specification patterns
  1548 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1549 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1550 Command 'print_theory' outputs the normalized system of recursive
  1551 equations, see section "definitions".
  1552 
  1553 * Configuration options are maintained within the theory or proof
  1554 context (with name and type bool/int/string), providing a very simple
  1555 interface to a poor-man's version of general context data.  Tools may
  1556 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1557 these values using Config.get etc.  Users may change options via an
  1558 associated attribute of the same name.  This form of context
  1559 declaration works particularly well with commands 'declare' or
  1560 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1561 very easy to avoid global references, which would not observe Isar
  1562 toplevel undo/redo and fail to work with multithreading.
  1563 
  1564 Various global ML references of Pure and HOL have been turned into
  1565 configuration options:
  1566 
  1567   Unify.search_bound		unify_search_bound
  1568   Unify.trace_bound		unify_trace_bound
  1569   Unify.trace_simp		unify_trace_simp
  1570   Unify.trace_types		unify_trace_types
  1571   Simplifier.simp_depth_limit	simp_depth_limit
  1572   Blast.depth_limit		blast_depth_limit
  1573   DatatypeProp.dtK		datatype_distinctness_limit
  1574   fast_arith_neq_limit  	fast_arith_neq_limit
  1575   fast_arith_split_limit	fast_arith_split_limit
  1576 
  1577 * Named collections of theorems may be easily installed as context
  1578 data using the functor NamedThmsFun (see also
  1579 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1580 attributes; there is also a toplevel print command.  This facility is
  1581 just a common case of general context data, which is the preferred way
  1582 for anything more complex than just a list of facts in canonical
  1583 order.
  1584 
  1585 * Isar: command 'declaration' augments a local theory by generic
  1586 declaration functions written in ML.  This enables arbitrary content
  1587 being added to the context, depending on a morphism that tells the
  1588 difference of the original declaration context wrt. the application
  1589 context encountered later on.
  1590 
  1591 * Isar: proper interfaces for simplification procedures.  Command
  1592 'simproc_setup' declares named simprocs (with match patterns, and body
  1593 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1594 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1595 
  1596 * Isar: an extra pair of brackets around attribute declarations
  1597 abbreviates a theorem reference involving an internal dummy fact,
  1598 which will be ignored later --- only the effect of the attribute on
  1599 the background context will persist.  This form of in-place
  1600 declarations is particularly useful with commands like 'declare' and
  1601 'using', for example ``have A using [[simproc a]] by simp''.
  1602 
  1603 * Isar: method "assumption" (and implicit closing of subproofs) now
  1604 takes simple non-atomic goal assumptions into account: after applying
  1605 an assumption as a rule the resulting subgoals are solved by atomic
  1606 assumption steps.  This is particularly useful to finish 'obtain'
  1607 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1608 without referring to the original premise "!!x. P x ==> thesis" in the
  1609 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1610 more permissive.
  1611 
  1612 * Isar: implicit use of prems from the Isar proof context is
  1613 considered a legacy feature.  Common applications like ``have A .''
  1614 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1615 referencing facts explicitly here improves readability and
  1616 maintainability of proof texts.
  1617 
  1618 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1619 the obtained context from the course of reasoning!  For example:
  1620 
  1621   assume "EX x y. A x & B y"   -- "any previous fact"
  1622   then guess x and y by clarify
  1623 
  1624 This technique is potentially adventurous, depending on the facts and
  1625 proof tools being involved here.
  1626 
  1627 * Isar: known facts from the proof context may be specified as literal
  1628 propositions, using ASCII back-quote syntax.  This works wherever
  1629 named facts used to be allowed so far, in proof commands, proof
  1630 methods, attributes etc.  Literal facts are retrieved from the context
  1631 according to unification of type and term parameters.  For example,
  1632 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1633 theorems in the current context, then these are valid literal facts:
  1634 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1635 
  1636 There is also a proof method "fact" which does the same composition
  1637 for explicit goal states, e.g. the following proof texts coincide with
  1638 certain special cases of literal facts:
  1639 
  1640   have "A" by fact                 ==  note `A`
  1641   have "A ==> B" by fact           ==  note `A ==> B`
  1642   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1643   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1644 
  1645 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1646 outer syntax.  Thus symbolic identifiers may be used without
  1647 additional white space in declarations like this: ``assume *: A''.
  1648 
  1649 * Isar: 'print_facts' prints all local facts of the current context,
  1650 both named and unnamed ones.
  1651 
  1652 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1653 
  1654   def x == "t" and y == "u"
  1655 
  1656 * Isar: added command 'unfolding', which is structurally similar to
  1657 'using', but affects both the goal state and facts by unfolding given
  1658 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1659 'unfolded' attribute may be replaced by first-class proof text.
  1660 
  1661 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1662 and command 'unfolding' now all support object-level equalities
  1663 (potentially conditional).  The underlying notion of rewrite rule is
  1664 analogous to the 'rule_format' attribute, but *not* that of the
  1665 Simplifier (which is usually more generous).
  1666 
  1667 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1668 premises of a theorem by n. Useful in conjunction with drule.
  1669 
  1670 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1671 method expression within a sandbox consisting of the first N
  1672 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1673 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1674 simplifies all new goals that emerge from applying rule foo to the
  1675 originally first one.
  1676 
  1677 * Isar: schematic goals are no longer restricted to higher-order
  1678 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1679 expected.
  1680 
  1681 * Isar: the conclusion of a long theorem statement is now either
  1682 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1683 (essentially a disjunction of cases with local parameters and
  1684 assumptions).  The latter allows to express general elimination rules
  1685 adequately; in this notation common elimination rules look like this:
  1686 
  1687   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1688     assumes "EX x. P x"
  1689     obtains x where "P x"
  1690 
  1691   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1692     assumes "A & B"
  1693     obtains A and B
  1694 
  1695   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1696     assumes "A | B"
  1697     obtains
  1698       A
  1699     | B
  1700 
  1701 The subsequent classical rules even refer to the formal "thesis"
  1702 explicitly:
  1703 
  1704   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1705     obtains "~ thesis"
  1706 
  1707   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1708     obtains "thesis ==> something"
  1709 
  1710 The actual proof of an 'obtains' statement is analogous to that of the
  1711 Isar proof element 'obtain', only that there may be several cases.
  1712 Optional case names may be specified in parentheses; these will be
  1713 available both in the present proof and as annotations in the
  1714 resulting rule, for later use with the 'cases' method (cf. attribute
  1715 case_names).
  1716 
  1717 * Isar: the assumptions of a long theorem statement are available as
  1718 "assms" fact in the proof context.  This is more appropriate than the
  1719 (historical) "prems", which refers to all assumptions of the current
  1720 context, including those from the target locale, proof body etc.
  1721 
  1722 * Isar: 'print_statement' prints theorems from the current theory or
  1723 proof context in long statement form, according to the syntax of a
  1724 top-level lemma.
  1725 
  1726 * Isar: 'obtain' takes an optional case name for the local context
  1727 introduction rule (default "that").
  1728 
  1729 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1730 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1731 to occur.
  1732 
  1733 * Pure: syntax "CONST name" produces a fully internalized constant
  1734 according to the current context.  This is particularly useful for
  1735 syntax translations that should refer to internal constant
  1736 representations independently of name spaces.
  1737 
  1738 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1739 instead of "FOO ". This allows multiple binder declarations to coexist
  1740 in the same context.  INCOMPATIBILITY.
  1741 
  1742 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1743 primitive that also works in a locale context (both for constants and
  1744 fixed variables). Type declaration and internal syntactic representation
  1745 of given constants retrieved from the context. Likewise, the
  1746 'no_notation' command allows to remove given syntax annotations from the
  1747 current context.
  1748 
  1749 * Isar/locales: new derived specification elements 'axiomatization',
  1750 'definition', 'abbreviation', which support type-inference, admit
  1751 object-level specifications (equality, equivalence).  See also the
  1752 isar-ref manual.  Examples:
  1753 
  1754   axiomatization
  1755     eq  (infix "===" 50) where
  1756     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1757 
  1758   definition "f x y = x + y + 1"
  1759   definition g where "g x = f x x"
  1760 
  1761   abbreviation
  1762     neq  (infix "=!=" 50) where
  1763     "x =!= y == ~ (x === y)"
  1764 
  1765 These specifications may be also used in a locale context.  Then the
  1766 constants being introduced depend on certain fixed parameters, and the
  1767 constant name is qualified by the locale base name.  An internal
  1768 abbreviation takes care for convenient input and output, making the
  1769 parameters implicit and using the original short name.  See also
  1770 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1771 entities from a monomorphic theory.
  1772 
  1773 Presently, abbreviations are only available 'in' a target locale, but
  1774 not inherited by general import expressions.  Also note that
  1775 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1776 'translations' in common applications.  The "no_abbrevs" print mode
  1777 prevents folding of abbreviations in term output.
  1778 
  1779 Concrete syntax is attached to specified constants in internal form,
  1780 independently of name spaces.  The parse tree representation is
  1781 slightly different -- use 'notation' instead of raw 'syntax', and
  1782 'translations' with explicit "CONST" markup to accommodate this.
  1783 
  1784 * Pure/Isar: unified syntax for new-style specification mechanisms
  1785 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1786 full type inference and dummy patterns ("_").  For example:
  1787 
  1788   definition "K x _ = x"
  1789 
  1790   inductive conj for A B
  1791   where "A ==> B ==> conj A B"
  1792 
  1793 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1794 the current context.  Print mode "no_abbrevs" prevents inversion of
  1795 abbreviations on output.
  1796 
  1797 * Isar/locales: improved parameter handling: use of locales "var" and
  1798 "struct" no longer necessary; - parameter renamings are no longer
  1799 required to be injective.  For example, this allows to define
  1800 endomorphisms as locale endom = homom mult mult h.
  1801 
  1802 * Isar/locales: changed the way locales with predicates are defined.
  1803 Instead of accumulating the specification, the imported expression is
  1804 now an interpretation.  INCOMPATIBILITY: different normal form of
  1805 locale expressions.  In particular, in interpretations of locales with
  1806 predicates, goals repesenting already interpreted fragments are not
  1807 removed automatically.  Use methods `intro_locales' and
  1808 `unfold_locales'; see below.
  1809 
  1810 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1811 provide backward reasoning on locales predicates.  The methods are
  1812 aware of interpretations and discharge corresponding goals.
  1813 `intro_locales' is less aggressive then `unfold_locales' and does not
  1814 unfold predicates to assumptions.
  1815 
  1816 * Isar/locales: the order in which locale fragments are accumulated
  1817 has changed.  This enables to override declarations from fragments due
  1818 to interpretations -- for example, unwanted simp rules.
  1819 
  1820 * Isar/locales: interpretation in theories and proof contexts has been
  1821 extended.  One may now specify (and prove) equations, which are
  1822 unfolded in interpreted theorems.  This is useful for replacing
  1823 defined concepts (constants depending on locale parameters) by
  1824 concepts already existing in the target context.  Example:
  1825 
  1826   interpretation partial_order ["op <= :: [int, int] => bool"]
  1827     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1828 
  1829 Typically, the constant `partial_order.less' is created by a
  1830 definition specification element in the context of locale
  1831 partial_order.
  1832 
  1833 * Method "induct": improved internal context management to support
  1834 local fixes and defines on-the-fly. Thus explicit meta-level
  1835 connectives !!  and ==> are rarely required anymore in inductive goals
  1836 (using object-logic connectives for this purpose has been long
  1837 obsolete anyway). Common proof patterns are explained in
  1838 src/HOL/Induct/Common_Patterns.thy, see also
  1839 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1840 examples.
  1841 
  1842 * Method "induct": improved handling of simultaneous goals. Instead of
  1843 introducing object-level conjunction, the statement is now split into
  1844 several conclusions, while the corresponding symbolic cases are nested
  1845 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1846 see src/HOL/Induct/Common_Patterns.thy, for example.
  1847 
  1848 * Method "induct": mutual induction rules are now specified as a list
  1849 of rule sharing the same induction cases. HOL packages usually provide
  1850 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1851 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1852 mutual induction rules differently, i.e. like this:
  1853 
  1854   (induct rule: foo_bar.inducts)
  1855   (induct set: foo bar)
  1856   (induct pred: foo bar)
  1857   (induct type: foo bar)
  1858 
  1859 The ML function ProjectRule.projections turns old-style rules into the
  1860 new format.
  1861 
  1862 * Method "coinduct": dual of induction, see
  1863 src/HOL/Library/Coinductive_List.thy for various examples.
  1864 
  1865 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1866 considered a legacy feature.
  1867 
  1868 * Attribute "symmetric" produces result with standardized schematic
  1869 variables (index 0).  Potential INCOMPATIBILITY.
  1870 
  1871 * Simplifier: by default the simplifier trace only shows top level
  1872 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1873 default. Thus there is less danger of being flooded by the trace. The
  1874 trace indicates where parts have been suppressed.
  1875   
  1876 * Provers/classical: removed obsolete classical version of elim_format
  1877 attribute; classical elim/dest rules are now treated uniformly when
  1878 manipulating the claset.
  1879 
  1880 * Provers/classical: stricter checks to ensure that supplied intro,
  1881 dest and elim rules are well-formed; dest and elim rules must have at
  1882 least one premise.
  1883 
  1884 * Provers/classical: attributes dest/elim/intro take an optional
  1885 weight argument for the rule (just as the Pure versions).  Weights are
  1886 ignored by automated tools, but determine the search order of single
  1887 rule steps.
  1888 
  1889 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1890 where the body does not mention the bound variable.  Note that dummy
  1891 patterns implicitly depend on their context of bounds, which makes
  1892 "{_. _}" match any set comprehension as expected.  Potential
  1893 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1894 constant "_idtdummy" in the binding position.
  1895 
  1896 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1897 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1898 for example "A -> B" => "Pi A (%_. B)".
  1899 
  1900 * Pure: 'class_deps' command visualizes the subclass relation, using
  1901 the graph browser tool.
  1902 
  1903 * Pure: 'print_theory' now suppresses certain internal declarations by
  1904 default; use '!' option for full details.
  1905 
  1906 
  1907 *** HOL ***
  1908 
  1909 * Method "metis" proves goals by applying the Metis general-purpose
  1910 resolution prover (see also http://gilith.com/software/metis/).
  1911 Examples are in the directory MetisExamples.  WARNING: the
  1912 Isabelle/HOL-Metis integration does not yet work properly with
  1913 multi-threading.
  1914   
  1915 * Command 'sledgehammer' invokes external automatic theorem provers as
  1916 background processes.  It generates calls to the "metis" method if
  1917 successful. These can be pasted into the proof.  Users do not have to
  1918 wait for the automatic provers to return.  WARNING: does not really
  1919 work with multi-threading.
  1920 
  1921 * New "auto_quickcheck" feature tests outermost goal statements for
  1922 potential counter-examples.  Controlled by ML references
  1923 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1924 5000 milliseconds).  Fails silently if statements is outside of
  1925 executable fragment, or any other codgenerator problem occurs.
  1926 
  1927 * New constant "undefined" with axiom "undefined x = undefined".
  1928 
  1929 * Added class "HOL.eq", allowing for code generation with polymorphic
  1930 equality.
  1931 
  1932 * Some renaming of class constants due to canonical name prefixing in
  1933 the new 'class' package:
  1934 
  1935     HOL.abs ~> HOL.abs_class.abs
  1936     HOL.divide ~> HOL.divide_class.divide
  1937     0 ~> HOL.zero_class.zero
  1938     1 ~> HOL.one_class.one
  1939     op + ~> HOL.plus_class.plus
  1940     op - ~> HOL.minus_class.minus
  1941     uminus ~> HOL.minus_class.uminus
  1942     op * ~> HOL.times_class.times
  1943     op < ~> HOL.ord_class.less
  1944     op <= > HOL.ord_class.less_eq
  1945     Nat.power ~> Power.power_class.power
  1946     Nat.size ~> Nat.size_class.size
  1947     Numeral.number_of ~> Numeral.number_class.number_of
  1948     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1949     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1950     Orderings.min ~> Orderings.ord_class.min
  1951     Orderings.max ~> Orderings.ord_class.max
  1952     Divides.op div ~> Divides.div_class.div
  1953     Divides.op mod ~> Divides.div_class.mod
  1954     Divides.op dvd ~> Divides.div_class.dvd
  1955 
  1956 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1957 
  1958 a) User-defined constants using any of the names "plus", "minus",
  1959 "times", "less" or "less_eq". The standard syntax translations for
  1960 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1961 names.
  1962 
  1963 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1964 INCOMPATIBILITY: use more specific names.
  1965 
  1966 c) Permutative equations (e.g. "a + b = b + a")
  1967 Since the change of names also changes the order of terms, permutative
  1968 rewrite rules may get applied in a different order. Experience shows
  1969 that this is rarely the case (only two adaptions in the whole Isabelle
  1970 distribution).  INCOMPATIBILITY: rewrite proofs
  1971 
  1972 d) ML code directly refering to constant names
  1973 This in general only affects hand-written proof tactics, simprocs and
  1974 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1975 Consider using @{const_name} antiquotation.
  1976 
  1977 * New class "default" with associated constant "default".
  1978 
  1979 * Function "sgn" is now overloaded and available on int, real, complex
  1980 (and other numeric types), using class "sgn".  Two possible defs of
  1981 sgn are given as equational assumptions in the classes sgn_if and
  1982 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1983 INCOMPATIBILITY.
  1984 
  1985 * Locale "partial_order" now unified with class "order" (cf. theory
  1986 Orderings), added parameter "less".  INCOMPATIBILITY.
  1987 
  1988 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1989 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1990 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1991 
  1992 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1993 changed order of proof goals in instance proofs.
  1994 
  1995 * The transitivity reasoner for partial and linear orders is set up
  1996 for classes "order" and "linorder".  Instances of the reasoner are available
  1997 in all contexts importing or interpreting the corresponding locales.
  1998 Method "order" invokes the reasoner separately; the reasoner
  1999 is also integrated with the Simplifier as a solver.  Diagnostic
  2000 command 'print_orders' shows the available instances of the reasoner
  2001 in the current context.
  2002 
  2003 * Localized monotonicity predicate in theory "Orderings"; integrated
  2004 lemmas max_of_mono and min_of_mono with this predicate.
  2005 INCOMPATIBILITY.
  2006 
  2007 * Formulation of theorem "dense" changed slightly due to integration
  2008 with new class dense_linear_order.
  2009 
  2010 * Uniform lattice theory development in HOL.
  2011 
  2012     constants "meet" and "join" now named "inf" and "sup"
  2013     constant "Meet" now named "Inf"
  2014 
  2015     classes "meet_semilorder" and "join_semilorder" now named
  2016       "lower_semilattice" and "upper_semilattice"
  2017     class "lorder" now named "lattice"
  2018     class "comp_lat" now named "complete_lattice"
  2019 
  2020     Instantiation of lattice classes allows explicit definitions
  2021     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2022 
  2023   INCOMPATIBILITY.  Theorem renames:
  2024 
  2025     meet_left_le            ~> inf_le1
  2026     meet_right_le           ~> inf_le2
  2027     join_left_le            ~> sup_ge1
  2028     join_right_le           ~> sup_ge2
  2029     meet_join_le            ~> inf_sup_ord
  2030     le_meetI                ~> le_infI
  2031     join_leI                ~> le_supI
  2032     le_meet                 ~> le_inf_iff
  2033     le_join                 ~> ge_sup_conv
  2034     meet_idempotent         ~> inf_idem
  2035     join_idempotent         ~> sup_idem
  2036     meet_comm               ~> inf_commute
  2037     join_comm               ~> sup_commute
  2038     meet_leI1               ~> le_infI1
  2039     meet_leI2               ~> le_infI2
  2040     le_joinI1               ~> le_supI1
  2041     le_joinI2               ~> le_supI2
  2042     meet_assoc              ~> inf_assoc
  2043     join_assoc              ~> sup_assoc
  2044     meet_left_comm          ~> inf_left_commute
  2045     meet_left_idempotent    ~> inf_left_idem
  2046     join_left_comm          ~> sup_left_commute
  2047     join_left_idempotent    ~> sup_left_idem
  2048     meet_aci                ~> inf_aci
  2049     join_aci                ~> sup_aci
  2050     le_def_meet             ~> le_iff_inf
  2051     le_def_join             ~> le_iff_sup
  2052     join_absorp2            ~> sup_absorb2
  2053     join_absorp1            ~> sup_absorb1
  2054     meet_absorp1            ~> inf_absorb1
  2055     meet_absorp2            ~> inf_absorb2
  2056     meet_join_absorp        ~> inf_sup_absorb
  2057     join_meet_absorp        ~> sup_inf_absorb
  2058     distrib_join_le         ~> distrib_sup_le
  2059     distrib_meet_le         ~> distrib_inf_le
  2060 
  2061     add_meet_distrib_left   ~> add_inf_distrib_left
  2062     add_join_distrib_left   ~> add_sup_distrib_left
  2063     is_join_neg_meet        ~> is_join_neg_inf
  2064     is_meet_neg_join        ~> is_meet_neg_sup
  2065     add_meet_distrib_right  ~> add_inf_distrib_right
  2066     add_join_distrib_right  ~> add_sup_distrib_right
  2067     add_meet_join_distribs  ~> add_sup_inf_distribs
  2068     join_eq_neg_meet        ~> sup_eq_neg_inf
  2069     meet_eq_neg_join        ~> inf_eq_neg_sup
  2070     add_eq_meet_join        ~> add_eq_inf_sup
  2071     meet_0_imp_0            ~> inf_0_imp_0
  2072     join_0_imp_0            ~> sup_0_imp_0
  2073     meet_0_eq_0             ~> inf_0_eq_0
  2074     join_0_eq_0             ~> sup_0_eq_0
  2075     neg_meet_eq_join        ~> neg_inf_eq_sup
  2076     neg_join_eq_meet        ~> neg_sup_eq_inf
  2077     join_eq_if              ~> sup_eq_if
  2078 
  2079     mono_meet               ~> mono_inf
  2080     mono_join               ~> mono_sup
  2081     meet_bool_eq            ~> inf_bool_eq
  2082     join_bool_eq            ~> sup_bool_eq
  2083     meet_fun_eq             ~> inf_fun_eq
  2084     join_fun_eq             ~> sup_fun_eq
  2085     meet_set_eq             ~> inf_set_eq
  2086     join_set_eq             ~> sup_set_eq
  2087     meet1_iff               ~> inf1_iff
  2088     meet2_iff               ~> inf2_iff
  2089     meet1I                  ~> inf1I
  2090     meet2I                  ~> inf2I
  2091     meet1D1                 ~> inf1D1
  2092     meet2D1                 ~> inf2D1
  2093     meet1D2                 ~> inf1D2
  2094     meet2D2                 ~> inf2D2
  2095     meet1E                  ~> inf1E
  2096     meet2E                  ~> inf2E
  2097     join1_iff               ~> sup1_iff
  2098     join2_iff               ~> sup2_iff
  2099     join1I1                 ~> sup1I1
  2100     join2I1                 ~> sup2I1
  2101     join1I1                 ~> sup1I1
  2102     join2I2                 ~> sup1I2
  2103     join1CI                 ~> sup1CI
  2104     join2CI                 ~> sup2CI
  2105     join1E                  ~> sup1E
  2106     join2E                  ~> sup2E
  2107 
  2108     is_meet_Meet            ~> is_meet_Inf
  2109     Meet_bool_def           ~> Inf_bool_def
  2110     Meet_fun_def            ~> Inf_fun_def
  2111     Meet_greatest           ~> Inf_greatest
  2112     Meet_lower              ~> Inf_lower
  2113     Meet_set_def            ~> Inf_set_def
  2114 
  2115     Sup_def                 ~> Sup_Inf
  2116     Sup_bool_eq             ~> Sup_bool_def
  2117     Sup_fun_eq              ~> Sup_fun_def
  2118     Sup_set_eq              ~> Sup_set_def
  2119 
  2120     listsp_meetI            ~> listsp_infI
  2121     listsp_meet_eq          ~> listsp_inf_eq
  2122 
  2123     meet_min                ~> inf_min
  2124     join_max                ~> sup_max
  2125 
  2126 * Added syntactic class "size"; overloaded constant "size" now has
  2127 type "'a::size ==> bool"
  2128 
  2129 * Internal reorganisation of `size' of datatypes: size theorems
  2130 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2131 simplification rules by default!); theorems "prod.size" now named
  2132 "*.size".
  2133 
  2134 * Class "div" now inherits from class "times" rather than "type".
  2135 INCOMPATIBILITY.
  2136 
  2137 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2138 Linorder etc.  have disappeared; operations defined in terms of
  2139 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2140 
  2141 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2142 
  2143 * HOL-Word: New extensive library and type for generic, fixed size
  2144 machine words, with arithemtic, bit-wise, shifting and rotating
  2145 operations, reflection into int, nat, and bool lists, automation for
  2146 linear arithmetic (by automatic reflection into nat or int), including
  2147 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2148 arithmetic type classes, supporting automatic simplification of
  2149 numerals on all operations.
  2150 
  2151 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2152 
  2153 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2154 
  2155 * Code generator library theories:
  2156   - Code_Integer represents HOL integers by big integer literals in target
  2157     languages.
  2158   - Code_Char represents HOL characters by character literals in target
  2159     languages.
  2160   - Code_Char_chr like Code_Char, but also offers treatment of character
  2161     codes; includes Code_Integer.
  2162   - Executable_Set allows to generate code for finite sets using lists.
  2163   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2164     denominator).
  2165   - Executable_Real implements a subset of real numbers, namly those
  2166     representable by rational numbers.
  2167   - Efficient_Nat implements natural numbers by integers, which in general will
  2168     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2169     includes Code_Integer.
  2170   - Code_Index provides an additional datatype index which is mapped to
  2171     target-language built-in integers.
  2172   - Code_Message provides an additional datatype message_string which is isomorphic to
  2173     strings; messages are mapped to target-language strings.
  2174 
  2175 * New package for inductive predicates
  2176 
  2177   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2178 
  2179     inductive
  2180       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2181       for z_1 :: U_1 and ... and z_n :: U_m
  2182     where
  2183       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2184     | ...
  2185 
  2186   with full support for type-inference, rather than
  2187 
  2188     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2189 
  2190     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2191     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2192 
  2193     inductive "s z_1 ... z_m"
  2194     intros
  2195       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2196       ...
  2197 
  2198   For backward compatibility, there is a wrapper allowing inductive
  2199   sets to be defined with the new package via
  2200 
  2201     inductive_set
  2202       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2203       for z_1 :: U_1 and ... and z_n :: U_m
  2204     where
  2205       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2206     | ...
  2207 
  2208   or
  2209 
  2210     inductive_set
  2211       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2212       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2213       for z_1 :: U_1 and ... and z_n :: U_m
  2214     where
  2215       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2216     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2217     | ...
  2218 
  2219   if the additional syntax "p ..." is required.
  2220 
  2221   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2222   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2223 
  2224   INCOMPATIBILITIES:
  2225 
  2226   - Since declaration and definition of inductive sets or predicates
  2227     is no longer separated, abbreviations involving the newly
  2228     introduced sets or predicates must be specified together with the
  2229     introduction rules after the 'where' keyword (see above), rather
  2230     than before the actual inductive definition.
  2231 
  2232   - The variables in induction and elimination rules are now
  2233     quantified in the order of their occurrence in the introduction
  2234     rules, rather than in alphabetical order. Since this may break
  2235     some proofs, these proofs either have to be repaired, e.g. by
  2236     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2237     statements of the form
  2238 
  2239       case (rule_i a_i_1 ... a_i_{k_i})
  2240 
  2241     or the old order of quantification has to be restored by explicitly adding
  2242     meta-level quantifiers in the introduction rules, i.e.
  2243 
  2244       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2245 
  2246   - The format of the elimination rules is now
  2247 
  2248       p z_1 ... z_m x_1 ... x_n ==>
  2249         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2250         ==> ... ==> P
  2251 
  2252     for predicates and
  2253 
  2254       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2255         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2256         ==> ... ==> P
  2257 
  2258     for sets rather than
  2259 
  2260       x : s z_1 ... z_m ==>
  2261         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2262         ==> ... ==> P
  2263 
  2264     This may require terms in goals to be expanded to n-tuples
  2265     (e.g. using case_tac or simplification with the split_paired_all
  2266     rule) before the above elimination rule is applicable.
  2267 
  2268   - The elimination or case analysis rules for (mutually) inductive
  2269     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2270     list of rules "p_1_..._p_k.elims" is no longer available.
  2271 
  2272 * New package "function"/"fun" for general recursive functions,
  2273 supporting mutual and nested recursion, definitions in local contexts,
  2274 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2275 for small examples, and the separate tutorial on the function
  2276 package. The old recdef "package" is still available as before, but
  2277 users are encouraged to use the new package.
  2278 
  2279 * Method "lexicographic_order" automatically synthesizes termination
  2280 relations as lexicographic combinations of size measures. 
  2281 
  2282 * Case-expressions allow arbitrary constructor-patterns (including
  2283 "_") and take their order into account, like in functional
  2284 programming.  Internally, this is translated into nested
  2285 case-expressions; missing cases are added and mapped to the predefined
  2286 constant "undefined". In complicated cases printing may no longer show
  2287 the original input but the internal form. Lambda-abstractions allow
  2288 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2289 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2290 variable.
  2291 
  2292 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2293 is an abbreviation for "of_nat :: nat => int". The simplification
  2294 rules for "of_nat" have been changed to work like "int" did
  2295 previously.  Potential INCOMPATIBILITY:
  2296   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2297   - of_nat_diff and of_nat_mult are no longer default simp rules
  2298 
  2299 * Method "algebra" solves polynomial equations over (semi)rings using
  2300 Groebner bases. The (semi)ring structure is defined by locales and the
  2301 tool setup depends on that generic context. Installing the method for
  2302 a specific type involves instantiating the locale and possibly adding
  2303 declarations for computation on the coefficients.  The method is
  2304 already instantiated for natural numbers and for the axiomatic class
  2305 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2306 CALCULEMUS 2007 for the general principles underlying this
  2307 architecture of context-aware proof-tools.
  2308 
  2309 * Method "ferrack" implements quantifier elimination over
  2310 special-purpose dense linear orders using locales (analogous to
  2311 "algebra"). The method is already installed for class
  2312 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2313 rat, etc.
  2314 
  2315 * Former constant "List.op @" now named "List.append".  Use ML
  2316 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2317 circumvent possible incompatibilities when working on ML level.
  2318 
  2319 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2320 
  2321 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2322 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2323 
  2324 * New syntax for Haskell-like list comprehension (input only), eg.
  2325 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2326 
  2327 * The special syntax for function "filter" has changed from [x :
  2328 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2329 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2330 
  2331 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2332 defined on nat only, as an abbreviation for [a..<Suc b]
  2333 INCOMPATIBILITY.
  2334 
  2335 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2336 
  2337 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2338 
  2339 * New lemma collection field_simps (an extension of ring_simps) for
  2340 manipulating (in)equations involving division. Multiplies with all
  2341 denominators that can be proved to be non-zero (in equations) or
  2342 positive/negative (in inequations).
  2343 
  2344 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2345 have been improved and renamed to ring_simps, group_simps and
  2346 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2347 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2348 
  2349 * Theory Library/Commutative_Ring: switched from recdef to function
  2350 package; constants add, mul, pow now curried.  Infix syntax for
  2351 algebraic operations.
  2352 
  2353 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2354 INCOMPATIBILITY.
  2355 
  2356 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2357 INCOMPATIBILITY.
  2358 
  2359 * HOL/records: generalised field-update to take a function on the
  2360 field rather than the new value: r(|A := x|) is translated to A_update
  2361 (K x) r The K-combinator that is internally used is called K_record.
  2362 INCOMPATIBILITY: Usage of the plain update functions has to be
  2363 adapted.
  2364  
  2365 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2366 * x = 0, which are required for a semiring.  Richer structures do not
  2367 inherit from semiring_0 anymore, because this property is a theorem
  2368 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2369 there is more to prove, but this is mostly trivial.
  2370 
  2371 * Class "recpower" is generalized to arbitrary monoids, not just
  2372 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2373 commutativity or semiring properties additionally.
  2374 
  2375 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2376 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2377 better use 'abbreviation'.
  2378 
  2379 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2380 
  2381 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2382 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2383 significant changes for setting up numeral syntax for types:
  2384   - New constants Numeral.pred and Numeral.succ instead
  2385       of former Numeral.bin_pred and Numeral.bin_succ.
  2386   - Use integer operations instead of bin_add, bin_mult and so on.
  2387   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2388   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2389 
  2390 See src/HOL/Integ/IntArith.thy for an example setup.
  2391 
  2392 * Command 'normal_form' computes the normal form of a term that may
  2393 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2394 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2395 heavy-duty computations because the functions are compiled to ML
  2396 first.  Correspondingly, a method "normalization" is provided.  See
  2397 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2398 
  2399 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2400 25 like -->); output depends on the "iff" print_mode, the default is
  2401 "A = B" (with priority 50).
  2402 
  2403 * Relations less (<) and less_eq (<=) are also available on type bool.
  2404 Modified syntax to disallow nesting without explicit parentheses,
  2405 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2406 INCOMPATIBILITY.
  2407 
  2408 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2409 
  2410 * Relation composition operator "op O" now has precedence 75 and binds
  2411 stronger than union and intersection. INCOMPATIBILITY.
  2412 
  2413 * The old set interval syntax "{m..n(}" (and relatives) has been
  2414 removed.  Use "{m..<n}" (and relatives) instead.
  2415 
  2416 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2417 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2418 ``declare [[simproc del: neq]]''.
  2419 
  2420 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2421 True/False.
  2422 
  2423 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2424 
  2425 * Theorem setsum_mult renamed to setsum_right_distrib.
  2426 
  2427 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2428 ``rule'' method.
  2429 
  2430 * Reimplemented methods "sat" and "satx", with several improvements:
  2431 goals no longer need to be stated as "<prems> ==> False", equivalences
  2432 (i.e. "=" on type bool) are handled, variable names of the form
  2433 "lit_<n>" are no longer reserved, significant speedup.
  2434 
  2435 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2436 zChaff is still supported as well.
  2437 
  2438 * 'inductive' and 'datatype': provide projections of mutual rules,
  2439 bundled as foo_bar.inducts;
  2440 
  2441 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2442 Library.
  2443 
  2444 * Library: moved theory Accessible_Part to main HOL.
  2445 
  2446 * Library: added theory Coinductive_List of potentially infinite lists
  2447 as greatest fixed-point.
  2448 
  2449 * Library: added theory AssocList which implements (finite) maps as
  2450 association lists.
  2451 
  2452 * Method "evaluation" solves goals (i.e. a boolean expression)
  2453 efficiently by compiling it to ML.  The goal is "proved" (via an
  2454 oracle) if it evaluates to True.
  2455 
  2456 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2457 also when invoked by the simplifier.  This results in the Simplifier
  2458 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2459 Configuration option fast_arith_split_limit=0 recovers the old
  2460 behavior.
  2461 
  2462 * Support for hex (0x20) and binary (0b1001) numerals.
  2463 
  2464 * New method: reify eqs (t), where eqs are equations for an
  2465 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2466 parameter, computes a term s::'b and a list xs::'a list and proves the
  2467 theorem I xs s = t. This is also known as reification or quoting. The
  2468 resulting theorem is applied to the subgoal to substitute t with I xs
  2469 s.  If t is omitted, the subgoal itself is reified.
  2470 
  2471 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2472 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2473 where f is supposed to be a computable function (in the sense of code
  2474 generattion). The method uses reify to compute s and xs as above then
  2475 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2476 r and finally gets the theorem t = r, which is again applied to the
  2477 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2478 
  2479 * Reflection: Automatic reification now handels binding, an example is
  2480 available in src/HOL/ex/ReflectionEx.thy
  2481 
  2482 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2483 command 'statespace' that is similar to 'record', but introduces an
  2484 abstract specification based on the locale infrastructure instead of
  2485 HOL types.  This leads to extra flexibility in composing state spaces,
  2486 in particular multiple inheritance and renaming of components.
  2487 
  2488 
  2489 *** HOL-Complex ***
  2490 
  2491 * Hyperreal: Functions root and sqrt are now defined on negative real
  2492 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2493 Nonnegativity side conditions have been removed from many lemmas, so
  2494 that more subgoals may now be solved by simplification; potential
  2495 INCOMPATIBILITY.
  2496 
  2497 * Real: new type classes formalize real normed vector spaces and
  2498 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2499 and norm :: 'a => real.
  2500 
  2501 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2502 reals into other types. The overloaded constant Reals :: 'a set is now
  2503 defined as range of_real; potential INCOMPATIBILITY.
  2504 
  2505 * Real: proper support for ML code generation, including 'quickcheck'.
  2506 Reals are implemented as arbitrary precision rationals.
  2507 
  2508 * Hyperreal: Several constants that previously worked only for the
  2509 reals have been generalized, so they now work over arbitrary vector
  2510 spaces. Type annotations may need to be added in some cases; potential
  2511 INCOMPATIBILITY.
  2512 
  2513   Infinitesimal  :: ('a::real_normed_vector) star set
  2514   HFinite        :: ('a::real_normed_vector) star set
  2515   HInfinite      :: ('a::real_normed_vector) star set
  2516   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2517   monad          :: ('a::real_normed_vector) star => 'a star set
  2518   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2519   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2520   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2521   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2522   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2523   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2524   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2525   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2526   sgn            :: 'a::real_normed_vector => 'a
  2527   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2528 
  2529 * Complex: Some complex-specific constants are now abbreviations for
  2530 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2531 hnorm.  Other constants have been entirely removed in favor of the
  2532 polymorphic versions (INCOMPATIBILITY):
  2533 
  2534   approx        <-- capprox
  2535   HFinite       <-- CFinite
  2536   HInfinite     <-- CInfinite
  2537   Infinitesimal <-- CInfinitesimal
  2538   monad         <-- cmonad
  2539   galaxy        <-- cgalaxy
  2540   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2541   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2542   (ns)deriv     <-- (ns)cderiv
  2543 
  2544 
  2545 *** HOL-Algebra ***
  2546 
  2547 * Formalisation of ideals and the quotient construction over rings.
  2548 
  2549 * Order and lattice theory no longer based on records.
  2550 INCOMPATIBILITY.
  2551 
  2552 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2553 greatest_closed.  INCOMPATIBILITY.
  2554 
  2555 * Method algebra is now set up via an attribute.  For examples see
  2556 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2557 of algebraic structures.
  2558 
  2559 * Renamed theory CRing to Ring.
  2560 
  2561 
  2562 *** HOL-Nominal ***
  2563 
  2564 * Substantial, yet incomplete support for nominal datatypes (binding
  2565 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2566 src/HOL/Nominal/Examples.  Prospective users should consult
  2567 http://isabelle.in.tum.de/nominal/
  2568 
  2569 
  2570 *** ML ***
  2571 
  2572 * ML basics: just one true type int, which coincides with IntInf.int
  2573 (even on SML/NJ).
  2574 
  2575 * ML within Isar: antiquotations allow to embed statically-checked
  2576 formal entities in the source, referring to the context available at
  2577 compile-time.  For example:
  2578 
  2579 ML {* @{sort "{zero,one}"} *}
  2580 ML {* @{typ "'a => 'b"} *}
  2581 ML {* @{term "%x. x"} *}
  2582 ML {* @{prop "x == y"} *}
  2583 ML {* @{ctyp "'a => 'b"} *}
  2584 ML {* @{cterm "%x. x"} *}
  2585 ML {* @{cprop "x == y"} *}
  2586 ML {* @{thm asm_rl} *}
  2587 ML {* @{thms asm_rl} *}
  2588 ML {* @{type_name c} *}
  2589 ML {* @{type_syntax c} *}
  2590 ML {* @{const_name c} *}
  2591 ML {* @{const_syntax c} *}
  2592 ML {* @{context} *}
  2593 ML {* @{theory} *}
  2594 ML {* @{theory Pure} *}
  2595 ML {* @{theory_ref} *}
  2596 ML {* @{theory_ref Pure} *}
  2597 ML {* @{simpset} *}
  2598 ML {* @{claset} *}
  2599 ML {* @{clasimpset} *}
  2600 
  2601 The same works for sources being ``used'' within an Isar context.
  2602 
  2603 * ML in Isar: improved error reporting; extra verbosity with
  2604 ML_Context.trace enabled.
  2605 
  2606 * Pure/General/table.ML: the join operations now works via exceptions
  2607 DUP/SAME instead of type option. This is simpler in simple cases, and
  2608 admits slightly more efficient complex applications.
  2609 
  2610 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2611 use Context.generic instead of just theory.
  2612 
  2613 * Pure: datatype Context.generic joins theory/Proof.context and
  2614 provides some facilities for code that works in either kind of
  2615 context, notably GenericDataFun for uniform theory and proof data.
  2616 
  2617 * Pure: simplified internal attribute type, which is now always
  2618 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2619 local (Proof.context) attributes have been discontinued, while
  2620 minimizing code duplication. Thm.rule_attribute and
  2621 Thm.declaration_attribute build canonical attributes; see also structure
  2622 Context for further operations on Context.generic, notably
  2623 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2624 declarations and definitions.
  2625 
  2626 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2627 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2628 init only required for impure data. INCOMPATIBILITY: empty really need
  2629 to be empty (no dependencies on theory content!)
  2630 
  2631 * Pure/kernel: consts certification ignores sort constraints given in
  2632 signature declarations. (This information is not relevant to the
  2633 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2634 potential INCOMPATIBILITY.
  2635 
  2636 * Pure: axiomatic type classes are now purely definitional, with
  2637 explicit proofs of class axioms and super class relations performed
  2638 internally. See Pure/axclass.ML for the main internal interfaces --
  2639 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2640 AxClass.axiomatize_class/classrel/arity supersede
  2641 Sign.add_classes/classrel/arities.
  2642 
  2643 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2644 global/local versions on theory vs. Proof.context have been
  2645 discontinued; Attrib.syntax and Method.syntax have been adapted
  2646 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2647 attributes, methods, etc.
  2648 
  2649 * Pure: several functions of signature "... -> theory -> theory * ..."
  2650 have been reoriented to "... -> theory -> ... * theory" in order to
  2651 allow natural usage in combination with the ||>, ||>>, |-> and
  2652 fold_map combinators.
  2653 
  2654 * Pure: official theorem names (closed derivations) and additional
  2655 comments (tags) are now strictly separate.  Name hints -- which are
  2656 maintained as tags -- may be attached any time without affecting the
  2657 derivation.
  2658 
  2659 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2660 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2661 achieve the old behaviour.
  2662 
  2663 * Pure: the "Goal" constant is now called "prop", supporting a
  2664 slightly more general idea of ``protecting'' meta-level rule
  2665 statements.
  2666 
  2667 * Pure: Logic.(un)varify only works in a global context, which is now
  2668 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2669 Logic.legacy_(un)varify as temporary workaround.
  2670 
  2671 * Pure: structure Name provides scalable operations for generating
  2672 internal variable names, notably Name.variants etc.  This replaces
  2673 some popular functions from term.ML:
  2674 
  2675   Term.variant		->  Name.variant
  2676   Term.variantlist	->  Name.variant_list
  2677   Term.invent_names	->  Name.invent_list
  2678 
  2679 Note that low-level renaming rarely occurs in new code -- operations
  2680 from structure Variable are used instead (see below).
  2681 
  2682 * Pure: structure Variable provides fundamental operations for proper
  2683 treatment of fixed/schematic variables in a context.  For example,
  2684 Variable.import introduces fixes for schematics of given facts and
  2685 Variable.export reverses the effect (up to renaming) -- this replaces
  2686 various freeze_thaw operations.
  2687 
  2688 * Pure: structure Goal provides simple interfaces for
  2689 init/conclude/finish and tactical prove operations (replacing former
  2690 Tactic.prove).  Goal.prove is the canonical way to prove results
  2691 within a given context; Goal.prove_global is a degraded version for
  2692 theory level goals, including a global Drule.standard.  Note that
  2693 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2694 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2695 in a locale context).
  2696 
  2697 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2698 and type checking (Syntax.check_term etc.), with common combinations
  2699 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2700 which are considered legacy and await removal.
  2701 
  2702 * Pure/Syntax: generic interfaces for type unchecking
  2703 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2704 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2705 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2706 available for convenience, but refer to the very same operations using
  2707 a mere theory instead of a full context.
  2708 
  2709 * Isar: simplified treatment of user-level errors, using exception
  2710 ERROR of string uniformly.  Function error now merely raises ERROR,
  2711 without any side effect on output channels.  The Isar toplevel takes
  2712 care of proper display of ERROR exceptions.  ML code may use plain
  2713 handle/can/try; cat_error may be used to concatenate errors like this:
  2714 
  2715   ... handle ERROR msg => cat_error msg "..."
  2716 
  2717 Toplevel ML code (run directly or through the Isar toplevel) may be
  2718 embedded into the Isar toplevel with exception display/debug like
  2719 this:
  2720 
  2721   Isar.toplevel (fn () => ...)
  2722 
  2723 INCOMPATIBILITY, removed special transform_error facilities, removed
  2724 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2725 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2726 -- use plain ERROR instead.
  2727 
  2728 * Isar: theory setup now has type (theory -> theory), instead of a
  2729 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2730 
  2731 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2732 ProofContext.debug/verbose flags.
  2733 
  2734 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2735 theory before entering a proof state.  Transactions now always see a
  2736 quasi-functional intermediate checkpoint, both in interactive and
  2737 batch mode.
  2738 
  2739 * Isar: simplified interfaces for outer syntax.  Renamed
  2740 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2741 OuterSyntax.add_parsers -- this functionality is now included in
  2742 OuterSyntax.command etc.  INCOMPATIBILITY.
  2743 
  2744 * Simplifier: the simpset of a running simplification process now
  2745 contains a proof context (cf. Simplifier.the_context), which is the
  2746 very context that the initial simpset has been retrieved from (by
  2747 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2748 (solver, looper etc.) may depend on arbitrary proof data.
  2749 
  2750 * Simplifier.inherit_context inherits the proof context (plus the
  2751 local bounds) of the current simplification process; any simproc
  2752 etc. that calls the Simplifier recursively should do this!  Removed
  2753 former Simplifier.inherit_bounds, which is already included here --
  2754 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2755 specify an explicit context using Simplifier.context/theory_context.
  2756 
  2757 * Simplifier/Classical Reasoner: more abstract interfaces
  2758 change_simpset/claset for modifying the simpset/claset reference of a
  2759 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2760 INCOMPATIBILITY.
  2761 
  2762 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2763 "Trueprop" etc.
  2764 
  2765 
  2766 *** System ***
  2767 
  2768 * settings: the default heap location within ISABELLE_HOME_USER now
  2769 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2770 Isabelle installations.
  2771 
  2772 * isabelle-process: option -S (secure mode) disables some critical
  2773 operations, notably runtime compilation and evaluation of ML source
  2774 code.
  2775 
  2776 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2777 
  2778 * Support for parallel execution, using native multicore support of
  2779 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2780 independent theories, according to the given theory header
  2781 specifications. The maximum number of worker threads is specified via
  2782 usedir option -M or the "max-threads" setting in Proof General. A
  2783 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2784 to 6 on a 8-core machine.  User-code needs to observe certain
  2785 guidelines for thread-safe programming, see appendix A in the Isar
  2786 Implementation manual.
  2787 
  2788 
  2789 
  2790 New in Isabelle2005 (October 2005)
  2791 ----------------------------------
  2792 
  2793 *** General ***
  2794 
  2795 * Theory headers: the new header syntax for Isar theories is
  2796 
  2797   theory <name>
  2798   imports <theory1> ... <theoryN>
  2799   uses <file1> ... <fileM>
  2800   begin
  2801 
  2802 where the 'uses' part is optional.  The previous syntax
  2803 
  2804   theory <name> = <theory1> + ... + <theoryN>:
  2805 
  2806 will disappear in the next release.  Use isatool fixheaders to convert
  2807 existing theory files.  Note that there is no change in ancient
  2808 non-Isar theories now, but these will disappear soon.
  2809 
  2810 * Theory loader: parent theories can now also be referred to via
  2811 relative and absolute paths.
  2812 
  2813 * Command 'find_theorems' searches for a list of criteria instead of a
  2814 list of constants. Known criteria are: intro, elim, dest, name:string,
  2815 simp:term, and any term. Criteria can be preceded by '-' to select
  2816 theorems that do not match. Intro, elim, dest select theorems that
  2817 match the current goal, name:s selects theorems whose fully qualified
  2818 name contain s, and simp:term selects all simplification rules whose
  2819 lhs match term.  Any other term is interpreted as pattern and selects
  2820 all theorems matching the pattern. Available in ProofGeneral under
  2821 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2822 
  2823   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2824 
  2825 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2826 matching the current goal as introduction rule and not having "HOL."
  2827 in their name (i.e. not being defined in theory HOL).
  2828 
  2829 * Command 'thms_containing' has been discontinued in favour of
  2830 'find_theorems'; INCOMPATIBILITY.
  2831 
  2832 * Communication with Proof General is now 8bit clean, which means that
  2833 Unicode text in UTF-8 encoding may be used within theory texts (both
  2834 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2835 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2836 
  2837   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2838   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2839 
  2840 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2841 Classical Reasoner.  Typical big applications run around 2 times
  2842 faster.
  2843 
  2844 
  2845 *** Document preparation ***
  2846 
  2847 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2848 of raw sources.  Only those symbols that do not require additional
  2849 LaTeX packages (depending on comments in isabellesym.sty) are
  2850 displayed properly, everything else is left verbatim.  isatool display
  2851 and isatool print are used as front ends (these are subject to the
  2852 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2853 
  2854 * Command tags control specific markup of certain regions of text,
  2855 notably folding and hiding.  Predefined tags include "theory" (for
  2856 theory begin and end), "proof" for proof commands, and "ML" for
  2857 commands involving ML code; the additional tags "visible" and
  2858 "invisible" are unused by default.  Users may give explicit tag
  2859 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2860 interpretation of tags is determined by the LaTeX job during document
  2861 preparation: see option -V of isatool usedir, or options -n and -t of
  2862 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2863 \isadroptag.
  2864 
  2865 Several document versions may be produced at the same time via isatool
  2866 usedir (the generated index.html will link all of them).  Typical
  2867 specifications include ''-V document=theory,proof,ML'' to present
  2868 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2869 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2870 these parts without any formal replacement text.  The Isabelle site
  2871 default settings produce ''document'' and ''outline'' versions as
  2872 specified above.
  2873 
  2874 * Several new antiquotations:
  2875 
  2876   @{term_type term} prints a term with its type annotated;
  2877 
  2878   @{typeof term} prints the type of a term;
  2879 
  2880   @{const const} is the same as @{term const}, but checks that the
  2881   argument is a known logical constant;
  2882 
  2883   @{term_style style term} and @{thm_style style thm} print a term or
  2884   theorem applying a "style" to it
  2885 
  2886   @{ML text}
  2887 
  2888 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2889 definitions, equations, inequations etc., 'concl' printing only the
  2890 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2891 to print the specified premise.  TermStyle.add_style provides an ML
  2892 interface for introducing further styles.  See also the "LaTeX Sugar"
  2893 document practical applications.  The ML antiquotation prints
  2894 type-checked ML expressions verbatim.
  2895 
  2896 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2897 and 'text' support optional locale specification '(in loc)', which
  2898 specifies the default context for interpreting antiquotations.  For
  2899 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2900 
  2901 * Option 'locale=NAME' of antiquotations specifies an alternative
  2902 context interpreting the subsequent argument.  For example: @{thm
  2903 [locale=lattice] inf_assoc}.
  2904 
  2905 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2906 a proof context.
  2907 
  2908 * Proper output of antiquotations for theory commands involving a
  2909 proof context (such as 'locale' or 'theorem (in loc) ...').
  2910 
  2911 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2912 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2913 
  2914 * isatool usedir: new option -C (default true) controls whether option
  2915 -D should include a copy of the original document directory; -C false
  2916 prevents unwanted effects such as copying of administrative CVS data.
  2917 
  2918 
  2919 *** Pure ***
  2920 
  2921 * Considerably improved version of 'constdefs' command.  Now performs
  2922 automatic type-inference of declared constants; additional support for
  2923 local structure declarations (cf. locales and HOL records), see also
  2924 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2925 sequential dependencies of definitions within a single 'constdefs'
  2926 section; moreover, the declared name needs to be an identifier.  If
  2927 all fails, consider to fall back on 'consts' and 'defs' separately.
  2928 
  2929 * Improved indexed syntax and implicit structures.  First of all,
  2930 indexed syntax provides a notational device for subscripted
  2931 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2932 expressions.  Secondly, in a local context with structure
  2933 declarations, number indexes \<^sub>n or the empty index (default
  2934 number 1) refer to a certain fixed variable implicitly; option
  2935 show_structs controls printing of implicit structures.  Typical
  2936 applications of these concepts involve record types and locales.
  2937 
  2938 * New command 'no_syntax' removes grammar declarations (and
  2939 translations) resulting from the given syntax specification, which is
  2940 interpreted in the same manner as for the 'syntax' command.
  2941 
  2942 * 'Advanced' translation functions (parse_translation etc.) may depend
  2943 on the signature of the theory context being presently used for
  2944 parsing/printing, see also isar-ref manual.
  2945 
  2946 * Improved 'oracle' command provides a type-safe interface to turn an
  2947 ML expression of type theory -> T -> term into a primitive rule of
  2948 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2949 is already included here); see also FOL/ex/IffExample.thy;
  2950 INCOMPATIBILITY.
  2951 
  2952 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2953 before); "cI" is no longer bound, use "c.intro" instead.
  2954 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2955 axclasses vs. locales.
  2956 
  2957 * Improved internal renaming of symbolic identifiers -- attach primes
  2958 instead of base 26 numbers.
  2959 
  2960 * New flag show_question_marks controls printing of leading question
  2961 marks in schematic variable names.
  2962 
  2963 * In schematic variable names, *any* symbol following \<^isub> or
  2964 \<^isup> is now treated as part of the base name.  For example, the
  2965 following works without printing of awkward ".0" indexes:
  2966 
  2967   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2968     by simp
  2969 
  2970 * Inner syntax includes (*(*nested*) comments*).
  2971 
  2972 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2973 annotations as "(00...)".
  2974 
  2975 * Clear separation of logical types and nonterminals, where the latter
  2976 may only occur in 'syntax' specifications or type abbreviations.
  2977 Before that distinction was only partially implemented via type class
  2978 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2979 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2980 exotic syntax specifications may require further adaption
  2981 (e.g. Cube/Cube.thy).
  2982 
  2983 * Removed obsolete type class "logic", use the top sort {} instead.
  2984 Note that non-logical types should be declared as 'nonterminals'
  2985 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2986 specifications.
  2987 
  2988 * Attributes 'induct' and 'cases': type or set names may now be
  2989 locally fixed variables as well.
  2990 
  2991 * Simplifier: can now control the depth to which conditional rewriting
  2992 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2993 Limit.
  2994 
  2995 * Simplifier: simplification procedures may now take the current
  2996 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2997 interface), which is very useful for calling the Simplifier
  2998 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2999 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3000 low-level mk_simproc no longer applies Logic.varify internally, to
  3001 allow for use in a context of fixed variables.
  3002 
  3003 * thin_tac now works even if the assumption being deleted contains !!
  3004 or ==>.  More generally, erule now works even if the major premise of
  3005 the elimination rule contains !! or ==>.
  3006 
  3007 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3008 
  3009 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3010 from Pure, which contains all common declarations already.  Both
  3011 theories are defined via plain Isabelle/Isar .thy files.
  3012 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3013 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3014 use isatool fixcpure to adapt your theory and ML sources.
  3015 
  3016 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3017 selections of theorems in named facts via index ranges.
  3018 
  3019 * 'print_theorems': in theory mode, really print the difference
  3020 wrt. the last state (works for interactive theory development only),
  3021 in proof mode print all local facts (cf. 'print_facts');
  3022 
  3023 * 'hide': option '(open)' hides only base names.
  3024 
  3025 * More efficient treatment of intermediate checkpoints in interactive
  3026 theory development.
  3027 
  3028 * Code generator is now invoked via code_module (incremental code
  3029 generation) and code_library (modular code generation, ML structures
  3030 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3031 must be quoted when used as identifiers.
  3032 
  3033 * New 'value' command for reading, evaluating and printing terms using
  3034 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3035 quoted when used as identifier.
  3036 
  3037 
  3038 *** Locales ***
  3039 
  3040 * New commands for the interpretation of locale expressions in
  3041 theories (1), locales (2) and proof contexts (3).  These generate
  3042 proof obligations from the expression specification.  After the
  3043 obligations have been discharged, theorems of the expression are added
  3044 to the theory, target locale or proof context.  The synopsis of the
  3045 commands is a follows:
  3046 
  3047   (1) interpretation expr inst
  3048   (2) interpretation target < expr
  3049   (3) interpret expr inst
  3050 
  3051 Interpretation in theories and proof contexts require a parameter
  3052 instantiation of terms from the current context.  This is applied to
  3053 specifications and theorems of the interpreted expression.
  3054 Interpretation in locales only permits parameter renaming through the
  3055 locale expression.  Interpretation is smart in that interpretations
  3056 that are active already do not occur in proof obligations, neither are
  3057 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3058 inspect active interpretations of a particular locale.  For details,
  3059 see the Isar Reference manual.  Examples can be found in
  3060 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3061 
  3062 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3063 'interpret' instead.
  3064 
  3065 * New context element 'constrains' for adding type constraints to
  3066 parameters.
  3067 
  3068 * Context expressions: renaming of parameters with syntax
  3069 redeclaration.
  3070 
  3071 * Locale declaration: 'includes' disallowed.
  3072 
  3073 * Proper static binding of attribute syntax -- i.e. types / terms /
  3074 facts mentioned as arguments are always those of the locale definition
  3075 context, independently of the context of later invocations.  Moreover,
  3076 locale operations (renaming and type / term instantiation) are applied
  3077 to attribute arguments as expected.
  3078 
  3079 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3080 actual attributes; rare situations may require Attrib.attribute to
  3081 embed those attributes into Attrib.src that lack concrete syntax.
  3082 Attribute implementations need to cooperate properly with the static
  3083 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3084 Attrib.XXX_thm etc. already do the right thing without further
  3085 intervention.  Only unusual applications -- such as "where" or "of"
  3086 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3087 on the context and the facts involved -- may have to assign parsed
  3088 values to argument tokens explicitly.
  3089 
  3090 * Changed parameter management in theorem generation for long goal
  3091 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3092 theorem statement in rare situations.
  3093 
  3094 * Locale inspection command 'print_locale' omits notes elements.  Use
  3095 'print_locale!' to have them included in the output.
  3096 
  3097 
  3098 *** Provers ***
  3099 
  3100 * Provers/hypsubst.ML: improved version of the subst method, for
  3101 single-step rewriting: it now works in bound variable contexts. New is
  3102 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3103 rewrite a different subterm than the original subst method, which is
  3104 still available as 'simplesubst'.
  3105 
  3106 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3107 and quasi orders.
  3108 
  3109 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3110 reflexive-transitive closure of relations.
  3111 
  3112 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3113 limit (previously hard-coded with a value of 20) user-definable.
  3114 
  3115 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3116 is peformed already.  Object-logics merely need to finish their
  3117 initial simpset configuration as before.  INCOMPATIBILITY.
  3118 
  3119 
  3120 *** HOL ***
  3121 
  3122 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3123 
  3124   syntax (epsilon)
  3125     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3126 
  3127 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3128 and x-symbol; use option '-m epsilon' to get it actually printed.
  3129 Moreover, the mathematically important symbolic identifier \<epsilon>
  3130 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3131 
  3132 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3133 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3134 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3135 support corresponding Isar calculations.
  3136 
  3137 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3138 instead of ":".
  3139 
  3140 * theory SetInterval: changed the syntax for open intervals:
  3141 
  3142   Old       New
  3143   {..n(}    {..<n}
  3144   {)n..}    {n<..}
  3145   {m..n(}   {m..<n}
  3146   {)m..n}   {m<..n}
  3147   {)m..n(}  {m<..<n}
  3148 
  3149 The old syntax is still supported but will disappear in the next
  3150 release.  For conversion use the following Emacs search and replace
  3151 patterns (these are not perfect but work quite well):
  3152 
  3153   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3154   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3155 
  3156 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3157 equalities in commutative rings; method 'algebra' provides a generic
  3158 interface.
  3159 
  3160 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3161 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3162 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3163 be a tuple pattern.
  3164 
  3165 Some new syntax forms are available:
  3166 
  3167   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3168   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3169   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3170   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3171 
  3172 The latter form "\<Sum>x < k. e" used to be based on a separate
  3173 function "Summation", which has been discontinued.
  3174 
  3175 * theory Finite_Set: in structured induction proofs, the insert case
  3176 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3177 (insert F x)'.
  3178 
  3179 * The 'refute' command has been extended to support a much larger
  3180 fragment of HOL, including axiomatic type classes, constdefs and
  3181 typedefs, inductive datatypes and recursion.
  3182 
  3183 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3184 Requires zChaff with proof generation to be installed.  See
  3185 HOL/ex/SAT_Examples.thy for examples.
  3186 
  3187 * Datatype induction via method 'induct' now preserves the name of the
  3188 induction variable. For example, when proving P(xs::'a list) by
  3189 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3190 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3191 in unstructured proof scripts.
  3192 
  3193 * Reworked implementation of records.  Improved scalability for
  3194 records with many fields, avoiding performance problems for type
  3195 inference. Records are no longer composed of nested field types, but
  3196 of nested extension types. Therefore the record type only grows linear
  3197 in the number of extensions and not in the number of fields.  The
  3198 top-level (users) view on records is preserved.  Potential
  3199 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3200 old record representation. The type generated for a record is called
  3201 <record_name>_ext_type.
  3202 
  3203 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3204 proofs triggered by a record definition or a simproc (if
  3205 quick_and_dirty is enabled).  Definitions of large records can take
  3206 quite long.
  3207 
  3208 New simproc record_upd_simproc for simplification of multiple record
  3209 updates enabled by default.  Moreover, trivial updates are also
  3210 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3211 occasionally, since simplification is more powerful by default.
  3212 
  3213 * typedef: proper support for polymorphic sets, which contain extra
  3214 type-variables in the term.
  3215 
  3216 * Simplifier: automatically reasons about transitivity chains
  3217 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3218 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3219 old proofs break occasionally as simplification may now solve more
  3220 goals than previously.
  3221 
  3222 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3223 present.  Works for all partial orders (class "order"), in particular
  3224 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3225 just like y <= x.
  3226 
  3227 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3228 bound variable or a constant then the let is unfolded.  Otherwise
  3229 first a is simplified to b, and then f b is simplified to g. If
  3230 possible we abstract b from g arriving at "let x = b in h x",
  3231 otherwise we unfold the let and arrive at g.  The simproc can be
  3232 enabled/disabled by the reference use_let_simproc.  Potential
  3233 INCOMPATIBILITY since simplification is more powerful by default.
  3234 
  3235 * Classical reasoning: the meson method now accepts theorems as arguments.
  3236 
  3237 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3238 jobs to provide advice on the provability of subgoals.
  3239 
  3240 * Theory OrderedGroup and Ring_and_Field: various additions and
  3241 improvements to faciliate calculations involving equalities and
  3242 inequalities.
  3243 
  3244 The following theorems have been eliminated or modified
  3245 (INCOMPATIBILITY):
  3246 
  3247   abs_eq             now named abs_of_nonneg
  3248   abs_of_ge_0        now named abs_of_nonneg
  3249   abs_minus_eq       now named abs_of_nonpos
  3250   imp_abs_id         now named abs_of_nonneg
  3251   imp_abs_neg_id     now named abs_of_nonpos
  3252   mult_pos           now named mult_pos_pos
  3253   mult_pos_le        now named mult_nonneg_nonneg
  3254   mult_pos_neg_le    now named mult_nonneg_nonpos
  3255   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3256   mult_neg           now named mult_neg_neg
  3257   mult_neg_le        now named mult_nonpos_nonpos
  3258 
  3259 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3260      
  3261      zero_le_square
  3262      not_square_less_zero 
  3263 
  3264   The following lemmas have been deleted from Real/RealPow:
  3265   
  3266      realpow_zero_zero
  3267      realpow_two
  3268      realpow_less
  3269      zero_le_power
  3270      realpow_two_le
  3271      abs_realpow_two
  3272      realpow_two_abs     
  3273 
  3274 * Theory Parity: added rules for simplifying exponents.
  3275 
  3276 * Theory List:
  3277 
  3278 The following theorems have been eliminated or modified
  3279 (INCOMPATIBILITY):
  3280 
  3281   list_all_Nil       now named list_all.simps(1)
  3282   list_all_Cons      now named list_all.simps(2)
  3283   list_all_conv      now named list_all_iff
  3284   set_mem_eq         now named mem_iff
  3285 
  3286 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3287 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3288 
  3289 
  3290 *** HOL-Complex ***
  3291 
  3292 * Theory RealDef: better support for embedding natural numbers and
  3293 integers in the reals.
  3294 
  3295 The following theorems have been eliminated or modified
  3296 (INCOMPATIBILITY):
  3297 
  3298   exp_ge_add_one_self  now requires no hypotheses
  3299   real_of_int_add      reversed direction of equality (use [symmetric])
  3300   real_of_int_minus    reversed direction of equality (use [symmetric])
  3301   real_of_int_diff     reversed direction of equality (use [symmetric])
  3302   real_of_int_mult     reversed direction of equality (use [symmetric])
  3303 
  3304 * Theory RComplete: expanded support for floor and ceiling functions.
  3305 
  3306 * Theory Ln is new, with properties of the natural logarithm
  3307 
  3308 * Hyperreal: There is a new type constructor "star" for making
  3309 nonstandard types.  The old type names are now type synonyms:
  3310 
  3311   hypreal = real star
  3312   hypnat = nat star
  3313   hcomplex = complex star
  3314 
  3315 * Hyperreal: Many groups of similarly-defined constants have been
  3316 replaced by polymorphic versions (INCOMPATIBILITY):
  3317 
  3318   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3319 
  3320   starset      <-- starsetNat, starsetC
  3321   *s*          <-- *sNat*, *sc*
  3322   starset_n    <-- starsetNat_n, starsetC_n
  3323   *sn*         <-- *sNatn*, *scn*
  3324   InternalSets <-- InternalNatSets, InternalCSets
  3325 
  3326   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3327   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3328   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3329   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3330   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3331 
  3332 * Hyperreal: Many type-specific theorems have been removed in favor of
  3333 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3334 
  3335   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3336   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3337   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3338   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3339   right_minus <-- hypreal_add_minus
  3340   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3341   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3342   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3343   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3344   mult_1_right <-- hcomplex_mult_one_right
  3345   mult_zero_left <-- hcomplex_mult_zero_left
  3346   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3347   right_distrib <-- hypnat_add_mult_distrib2
  3348   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3349   right_inverse <-- hypreal_mult_inverse
  3350   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3351   order_refl <-- {hypreal,hypnat}_le_refl
  3352   order_trans <-- {hypreal,hypnat}_le_trans
  3353   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3354   order_less_le <-- {hypreal,hypnat}_less_le
  3355   linorder_linear <-- {hypreal,hypnat}_le_linear
  3356   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3357   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3358   add_nonneg_nonneg <-- hypreal_le_add_order
  3359 
  3360 * Hyperreal: Separate theorems having to do with type-specific
  3361 versions of constants have been merged into theorems that apply to the
  3362 new polymorphic constants (INCOMPATIBILITY):
  3363 
  3364   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3365   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3366   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3367   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3368   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3369   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3370   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3371   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3372   STAR_diff <-- {STAR,STARC}_diff
  3373   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3374     STARC_hcomplex_of_complex}_image_subset
  3375   starset_n_Un <-- starset{Nat,C}_n_Un
  3376   starset_n_Int <-- starset{Nat,C}_n_Int
  3377   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3378   starset_n_diff <-- starset{Nat,C}_n_diff
  3379   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3380   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3381   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3382   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3383   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3384   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3385   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3386   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3387   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3388   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3389   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3390   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3391   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3392   starfun_diff <-- starfun{C,RC,CR}_diff
  3393   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3394   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3395   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3396   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3397   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3398   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3399   starfun_Id <-- starfunC_Id
  3400   starfun_approx <-- starfun{Nat,CR}_approx
  3401   starfun_capprox <-- starfun{C,RC}_capprox
  3402   starfun_abs <-- starfunNat_rabs
  3403   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3404   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3405   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3406   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3407   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3408   starfun_add_approx <-- starfunCR_add_approx
  3409   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3410   starfun_divide <-- starfun{C,CR,RC}_divide
  3411   starfun_n <-- starfun{Nat,C}_n
  3412   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3413   starfun_n_add <-- starfun{Nat,C}_n_add
  3414   starfun_n_add_minus <-- starfunNat_n_add_minus
  3415   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3416   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3417   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3418 
  3419   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3420   star_n_minus <-- {hypreal,hcomplex}_minus
  3421   star_n_diff <-- {hypreal,hcomplex}_diff
  3422   star_n_mult <-- {hypreal,hcomplex}_mult
  3423   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3424   star_n_le <-- {hypreal,hypnat}_le
  3425   star_n_less <-- {hypreal,hypnat}_less
  3426   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3427   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3428   star_n_abs <-- hypreal_hrabs
  3429   star_n_divide <-- hcomplex_divide
  3430 
  3431   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3432   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3433   star_of_diff <-- hypreal_of_real_diff
  3434   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3435   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3436   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3437   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3438   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3439   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3440   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3441   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3442   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3443   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3444   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3445   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3446   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3447   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3448   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3449   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3450   star_of_power <-- hypreal_of_real_power
  3451   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3452 
  3453 * Hyperreal: new method "transfer" that implements the transfer
  3454 principle of nonstandard analysis. With a subgoal that mentions
  3455 nonstandard types like "'a star", the command "apply transfer"
  3456 replaces it with an equivalent one that mentions only standard types.
  3457 To be successful, all free variables must have standard types; non-
  3458 standard variables must have explicit universal quantifiers.
  3459 
  3460 * Hyperreal: A theory of Taylor series.
  3461 
  3462 
  3463 *** HOLCF ***
  3464 
  3465 * Discontinued special version of 'constdefs' (which used to support
  3466 continuous functions) in favor of the general Pure one with full
  3467 type-inference.
  3468 
  3469 * New simplification procedure for solving continuity conditions; it
  3470 is much faster on terms with many nested lambda abstractions (cubic
  3471 instead of exponential time).
  3472 
  3473 * New syntax for domain package: selector names are now optional.
  3474 Parentheses should be omitted unless argument is lazy, for example:
  3475 
  3476   domain 'a stream = cons "'a" (lazy "'a stream")
  3477 
  3478 * New command 'fixrec' for defining recursive functions with pattern
  3479 matching; defining multiple functions with mutual recursion is also
  3480 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3481 sinr, or any data constructor defined by the domain package. The given
  3482 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3483 syntax and examples.
  3484 
  3485 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3486 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3487 but the proof obligation additionally includes an admissibility
  3488 requirement. The packages generate instances of class cpo or pcpo,
  3489 with continuity and strictness theorems for Rep and Abs.
  3490 
  3491 * HOLCF: Many theorems have been renamed according to a more standard naming
  3492 scheme (INCOMPATIBILITY):
  3493 
  3494   foo_inject:  "foo$x = foo$y ==> x = y"
  3495   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3496   foo_less:    "(foo$x << foo$y) = (x << y)"
  3497   foo_strict:  "foo$UU = UU"
  3498   foo_defined: "... ==> foo$x ~= UU"
  3499   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3500 
  3501 
  3502 *** ZF ***
  3503 
  3504 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3505 including the First Isomorphism Theorem (on quotienting by the kernel
  3506 of a homomorphism).
  3507 
  3508 * ZF/Simplifier: install second copy of type solver that actually
  3509 makes use of TC rules declared to Isar proof contexts (or locales);
  3510 the old version is still required for ML proof scripts.
  3511 
  3512 
  3513 *** Cube ***
  3514 
  3515 * Converted to Isar theory format; use locales instead of axiomatic
  3516 theories.
  3517 
  3518 
  3519 *** ML ***
  3520 
  3521 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3522 for ||>, ||>>, |>>,
  3523 
  3524 * Pure/library.ML no longer defines its own option datatype, but uses
  3525 that of the SML basis, which has constructors NONE and SOME instead of
  3526 None and Some, as well as exception Option.Option instead of OPTION.
  3527 The functions the, if_none, is_some, is_none have been adapted
  3528 accordingly, while Option.map replaces apsome.
  3529 
  3530 * Pure/library.ML: the exception LIST has been given up in favour of
  3531 the standard exceptions Empty and Subscript, as well as
  3532 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3533 superceded by the standard hd and tl functions etc.
  3534 
  3535 A number of basic list functions are no longer exported to the ML
  3536 toplevel, as they are variants of predefined functions.  The following
  3537 suggests how one can translate existing code:
  3538 
  3539     rev_append xs ys = List.revAppend (xs, ys)
  3540     nth_elem (i, xs) = List.nth (xs, i)
  3541     last_elem xs = List.last xs
  3542     flat xss = List.concat xss
  3543     seq fs = List.app fs
  3544     partition P xs = List.partition P xs
  3545     mapfilter f xs = List.mapPartial f xs
  3546 
  3547 * Pure/library.ML: several combinators for linear functional
  3548 transformations, notably reverse application and composition:
  3549 
  3550   x |> f                f #> g
  3551   (x, y) |-> f          f #-> g
  3552 
  3553 * Pure/library.ML: introduced/changed precedence of infix operators:
  3554 
  3555   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3556   infix 2 ?;
  3557   infix 3 o oo ooo oooo;
  3558   infix 4 ~~ upto downto;
  3559 
  3560 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3561 infix operators.
  3562 
  3563 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3564 fold_map support linear functional transformations and nesting.  For
  3565 example:
  3566 
  3567   fold f [x1, ..., xN] y =
  3568     y |> f x1 |> ... |> f xN
  3569 
  3570   (fold o fold) f [xs1, ..., xsN] y =
  3571     y |> fold f xs1 |> ... |> fold f xsN
  3572 
  3573   fold f [x1, ..., xN] =
  3574     f x1 #> ... #> f xN
  3575 
  3576   (fold o fold) f [xs1, ..., xsN] =
  3577     fold f xs1 #> ... #> fold f xsN
  3578 
  3579 * Pure/library.ML: the following selectors on type 'a option are
  3580 available:
  3581 
  3582   the:               'a option -> 'a  (*partial*)
  3583   these:             'a option -> 'a  where 'a = 'b list
  3584   the_default: 'a -> 'a option -> 'a
  3585   the_list:          'a option -> 'a list
  3586 
  3587 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3588 basic operations for association lists, following natural argument
  3589 order; moreover the explicit equality predicate passed here avoids
  3590 potentially expensive polymorphic runtime equality checks.
  3591 The old functions may be expressed as follows:
  3592 
  3593   assoc = uncurry (AList.lookup (op =))
  3594   assocs = these oo AList.lookup (op =)
  3595   overwrite = uncurry (AList.update (op =)) o swap
  3596 
  3597 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3598 
  3599   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3600   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3601 
  3602 replacing make_keylist and keyfilter (occassionally used)
  3603 Naive rewrites:
  3604 
  3605   make_keylist = AList.make
  3606   keyfilter = AList.find (op =)
  3607 
  3608 * eq_fst and eq_snd now take explicit equality parameter, thus
  3609   avoiding eqtypes. Naive rewrites:
  3610 
  3611     eq_fst = eq_fst (op =)
  3612     eq_snd = eq_snd (op =)
  3613 
  3614 * Removed deprecated apl and apr (rarely used).
  3615   Naive rewrites:
  3616 
  3617     apl (n, op) =>>= curry op n
  3618     apr (op, m) =>>= fn n => op (n, m)
  3619 
  3620 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3621 provides a reasonably efficient light-weight implementation of sets as
  3622 lists.
  3623 
  3624 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3625 few new operations; existing lookup and update are now curried to
  3626 follow natural argument order (for use with fold etc.);
  3627 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3628 
  3629 * Pure/General: output via the Isabelle channels of
  3630 writeln/warning/error etc. is now passed through Output.output, with a
  3631 hook for arbitrary transformations depending on the print_mode
  3632 (cf. Output.add_mode -- the first active mode that provides a output
  3633 function wins).  Already formatted output may be embedded into further
  3634 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3635 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3636 accommodate easy composition of diagnostic messages etc.  Programmers
  3637 rarely need to care about Output.output or Output.raw at all, with
  3638 some notable exceptions: Output.output is required when bypassing the
  3639 standard channels (writeln etc.), or in token translations to produce
  3640 properly formatted results; Output.raw is required when capturing
  3641 already output material that will eventually be presented to the user
  3642 a second time.  For the default print mode, both Output.output and
  3643 Output.raw have no effect.
  3644 
  3645 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3646 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3647 cumulative results are displayed at the end of a batch session.
  3648 
  3649 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3650 replaced by File.platform_path and File.shell_path (with appropriate
  3651 hooks).  This provides a clean interface for unusual systems where the
  3652 internal and external process view of file names are different.
  3653 
  3654 * Pure: more efficient orders for basic syntactic entities: added
  3655 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3656 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3657 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3658 orders now -- potential INCOMPATIBILITY for code that depends on a
  3659 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3660 Library.sort_strings on result).
  3661 
  3662 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3663 fold_types traverse types/terms from left to right, observing natural
  3664 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3665 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3666 
  3667 * Pure: name spaces have been refined, with significant changes of the
  3668 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3669 to extern(_table).  The plain name entry path is superceded by a
  3670 general 'naming' context, which also includes the 'policy' to produce
  3671 a fully qualified name and external accesses of a fully qualified
  3672 name; NameSpace.extend is superceded by context dependent
  3673 Sign.declare_name.  Several theory and proof context operations modify
  3674 the naming context.  Especially note Theory.restore_naming and
  3675 ProofContext.restore_naming to get back to a sane state; note that
  3676 Theory.add_path is no longer sufficient to recover from
  3677 Theory.absolute_path in particular.
  3678 
  3679 * Pure: new flags short_names (default false) and unique_names
  3680 (default true) for controlling output of qualified names.  If
  3681 short_names is set, names are printed unqualified.  If unique_names is
  3682 reset, the name prefix is reduced to the minimum required to achieve
  3683 the original result when interning again, even if there is an overlap
  3684 with earlier declarations.
  3685 
  3686 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3687 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3688 (useful for printing error messages).  INCOMPATIBILITY.
  3689 
  3690 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3691 Theory.theory are now identified, referring to the universal
  3692 Context.theory (see Pure/context.ML).  Actual signature and theory
  3693 content is managed as theory data.  The old code and interfaces were
  3694 spread over many files and structures; the new arrangement introduces
  3695 considerable INCOMPATIBILITY to gain more clarity:
  3696 
  3697   Context -- theory management operations (name, identity, inclusion,
  3698     parents, ancestors, merge, etc.), plus generic theory data;
  3699 
  3700   Sign -- logical signature and syntax operations (declaring consts,
  3701     types, etc.), plus certify/read for common entities;
  3702 
  3703   Theory -- logical theory operations (stating axioms, definitions,
  3704     oracles), plus a copy of logical signature operations (consts,
  3705     types, etc.); also a few basic management operations (Theory.copy,
  3706     Theory.merge, etc.)
  3707 
  3708 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3709 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3710 for convenience -- they merely return the theory.
  3711 
  3712 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3713 
  3714 * Pure: the Isar proof context type is already defined early in Pure
  3715 as Context.proof (note that ProofContext.context and Proof.context are
  3716 aliases, where the latter is the preferred name).  This enables other
  3717 Isabelle components to refer to that type even before Isar is present.
  3718 
  3719 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3720 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3721 any of these kinds.  For example, Sign.intern typeK is now
  3722 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3723 Theory.hide_types.  Also note that former
  3724 Theory.hide_classes/types/consts are now
  3725 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3726 internalize their arguments!  INCOMPATIBILITY.
  3727 
  3728 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3729 datatype thmref (with constructors Name and NameSelection) instead of
  3730 plain string -- INCOMPATIBILITY;
  3731 
  3732 * Pure: cases produced by proof methods specify options, where NONE
  3733 means to remove case bindings -- INCOMPATIBILITY in
  3734 (RAW_)METHOD_CASES.
  3735 
  3736 * Pure: the following operations retrieve axioms or theorems from a
  3737 theory node or theory hierarchy, respectively:
  3738 
  3739   Theory.axioms_of: theory -> (string * term) list
  3740   Theory.all_axioms_of: theory -> (string * term) list
  3741   PureThy.thms_of: theory -> (string * thm) list
  3742   PureThy.all_thms_of: theory -> (string * thm) list
  3743 
  3744 * Pure: print_tac now outputs the goal through the trace channel.
  3745 
  3746 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3747 Reference Toplevel.debug (default false) controls detailed printing
  3748 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3749 controls execution profiling -- set to 1 for time and 2 for space
  3750 (both increase the runtime).
  3751 
  3752 * Isar session: The initial use of ROOT.ML is now always timed,
  3753 i.e. the log will show the actual process times, in contrast to the
  3754 elapsed wall-clock time that the outer shell wrapper produces.
  3755 
  3756 * Simplifier: improved handling of bound variables (nameless
  3757 representation, avoid allocating new strings).  Simprocs that invoke
  3758 the Simplifier recursively should use Simplifier.inherit_bounds to
  3759 avoid local name clashes.  Failure to do so produces warnings
  3760 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3761 for further details.
  3762 
  3763 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3764 bindings for all theorems stored within a given theory; this may help
  3765 in porting non-Isar theories to Isar ones, while keeping ML proof
  3766 scripts for the time being.
  3767 
  3768 * ML operator HTML.with_charset specifies the charset begin used for
  3769 generated HTML files.  For example:
  3770 
  3771   HTML.with_charset "utf-8" use_thy "Hebrew";
  3772   HTML.with_charset "utf-8" use_thy "Chinese";
  3773 
  3774 
  3775 *** System ***
  3776 
  3777 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3778 isabelle, isatool etc.).
  3779 
  3780 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3781 isatool doc, isatool mkdir, display_drafts etc.).
  3782 
  3783 * isatool usedir: option -f allows specification of the ML file to be
  3784 used by Isabelle; default is ROOT.ML.
  3785 
  3786 * New isatool version outputs the version identifier of the Isabelle
  3787 distribution being used.
  3788 
  3789 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3790 (containing Boolean satisfiability problems) into Isabelle/HOL
  3791 theories.
  3792 
  3793 
  3794 
  3795 New in Isabelle2004 (April 2004)
  3796 --------------------------------
  3797 
  3798 *** General ***
  3799 
  3800 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3801   Replaces linorder.ML.
  3802 
  3803 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3804   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3805   (\<a>...\<z>), are now considered normal letters, and can therefore
  3806   be used anywhere where an ASCII letter (a...zA...Z) has until
  3807   now. COMPATIBILITY: This obviously changes the parsing of some
  3808   terms, especially where a symbol has been used as a binder, say
  3809   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3810   as an identifier.  Fix it by inserting a space around former
  3811   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3812   existing theory and ML files.
  3813 
  3814 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3815 
  3816 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3817   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3818   a normal (but invisible) letter. For multiple letter subscripts repeat
  3819   \<^isub> like this: x\<^isub>1\<^isub>2.
  3820 
  3821 * Pure: There are now sub-/superscripts that can span more than one
  3822   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3823   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3824   superscript. The new control characters are not identifier parts.
  3825 
  3826 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3827   content of "..." to the latex file instead of \isacntrl... . The "..."
  3828   may consist of any printable characters excluding the end bracket >.
  3829 
  3830 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3831   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3832   declare constants "final", which prevents their being given a definition
  3833   later.  It is useful for constants whose behaviour is fixed axiomatically
  3834   rather than definitionally, such as the meta-logic connectives.
  3835 
  3836 * Pure: 'instance' now handles general arities with general sorts
  3837   (i.e. intersections of classes),
  3838 
  3839 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3840   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3841   It can be changed to alter the colors/layout of generated pages.
  3842 
  3843 
  3844 *** Isar ***
  3845 
  3846 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3847   cut_tac, subgoal_tac and thin_tac:
  3848   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3849     locales are no longer forced to write Isar proof scripts.
  3850     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3851     emulations.
  3852   - INCOMPATIBILITY: names of variables to be instantiated may no
  3853     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3854     This is consistent with the instantiation attribute "where".
  3855 
  3856 * Attributes "where" and "of":
  3857   - Now take type variables of instantiated theorem into account when reading
  3858     the instantiation string.  This fixes a bug that caused instantiated
  3859     theorems to have too special types in some circumstances.
  3860   - "where" permits explicit instantiations of type variables.
  3861 
  3862 * Calculation commands "moreover" and "also" no longer interfere with
  3863   current facts ("this"), admitting arbitrary combinations with "then"
  3864   and derived forms.
  3865 
  3866 * Locales:
  3867   - Goal statements involving the context element "includes" no longer
  3868     generate theorems with internal delta predicates (those ending on
  3869     "_axioms") in the premise.
  3870     Resolve particular premise with <locale>.intro to obtain old form.
  3871   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3872     specification and "includes" elements in goal statement.
  3873   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3874     [intro?] and [elim?] (respectively) by default.
  3875   - Experimental command for instantiation of locales in proof contexts:
  3876         instantiate <label>[<attrs>]: <loc>
  3877     Instantiates locale <loc> and adds all its theorems to the current context
  3878     taking into account their attributes.  Label and attrs are optional
  3879     modifiers, like in theorem declarations.  If present, names of
  3880     instantiated theorems are qualified with <label>, and the attributes
  3881     <attrs> are applied after any attributes these theorems might have already.
  3882       If the locale has assumptions, a chained fact of the form
  3883     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3884     are derived.  The command does not support old-style locales declared
  3885     with "locale (open)".
  3886       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3887 
  3888 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3889   (Isar) contexts.
  3890 
  3891 
  3892 *** HOL ***
  3893 
  3894 * Proof import: new image HOL4 contains the imported library from
  3895   the HOL4 system with about 2500 theorems. It is imported by
  3896   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3897   can be used like any other Isabelle image.  See
  3898   HOL/Import/HOL/README for more information.
  3899 
  3900 * Simplifier:
  3901   - Much improved handling of linear and partial orders.
  3902     Reasoners for linear and partial orders are set up for type classes
  3903     "linorder" and "order" respectively, and are added to the default simpset
  3904     as solvers.  This means that the simplifier can build transitivity chains
  3905     to solve goals from the assumptions.
  3906   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3907     of blast or auto after simplification become unnecessary because the goal
  3908     is solved by simplification already.
  3909 
  3910 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3911     all proved in axiomatic type classes for semirings, rings and fields.
  3912 
  3913 * Numerics:
  3914   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3915     now formalized using the Ring_and_Field theory mentioned above.
  3916   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3917     than before, because now they are set up once in a generic manner.
  3918   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3919     Look for the general versions in Ring_and_Field (and Power if they concern
  3920     exponentiation).
  3921 
  3922 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3923 
  3924 * Records:
  3925   - Record types are now by default printed with their type abbreviation
  3926     instead of the list of all field types. This can be configured via
  3927     the reference "print_record_type_abbr".
  3928   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3929     (not enabled by default).
  3930   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3931     EX x. x = sel r to True (not enabled by default).
  3932   - Tactic "record_split_simp_tac" to split and simplify records added.
  3933 
  3934 * 'specification' command added, allowing for definition by
  3935   specification.  There is also an 'ax_specification' command that
  3936   introduces the new constants axiomatically.
  3937 
  3938 * arith(_tac) is now able to generate counterexamples for reals as well.
  3939 
  3940 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3941 
  3942 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3943   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3944 
  3945 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3946   matrix theory to linear programming.
  3947 
  3948 * Unions and Intersections:
  3949   The latex output syntax of UN and INT has been changed
  3950   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3951   i.e. the index formulae has become a subscript.
  3952   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3953 
  3954 * Unions and Intersections over Intervals:
  3955   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3956   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3957   like in normal math, and corresponding versions for < and for intersection.
  3958 
  3959 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3960   lexicographic dictonary ordering has been added as "lexord".
  3961 
  3962 * ML: the legacy theory structures Int and List have been removed. They had
  3963   conflicted with ML Basis Library structures having the same names.
  3964 
  3965 * 'refute' command added to search for (finite) countermodels.  Only works
  3966   for a fragment of HOL.  The installation of an external SAT solver is
  3967   highly recommended.  See "HOL/Refute.thy" for details.
  3968 
  3969 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3970   formulae under an assignment of free variables to random values.
  3971   In contrast to 'refute', it can deal with inductive datatypes,
  3972   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3973   for examples.
  3974 
  3975 
  3976 *** HOLCF ***
  3977 
  3978 * Streams now come with concatenation and are part of the HOLCF image
  3979 
  3980 
  3981 
  3982 New in Isabelle2003 (May 2003)
  3983 ------------------------------
  3984 
  3985 *** General ***
  3986 
  3987 * Provers/simplifier:
  3988 
  3989   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3990     Assumptions are now subject to complete mutual simplification,
  3991     not just from left to right. The simplifier now preserves
  3992     the order of assumptions.
  3993 
  3994     Potential INCOMPATIBILITY:
  3995 
  3996     -- simp sometimes diverges where the old version did
  3997        not, e.g. invoking simp on the goal
  3998 
  3999         [| P (f x); y = x; f x = f y |] ==> Q
  4000 
  4001        now gives rise to the infinite reduction sequence
  4002 
  4003         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4004 
  4005        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4006        kind of problem.
  4007 
  4008     -- Tactics combining classical reasoner and simplification (such as auto)
  4009        are also affected by this change, because many of them rely on
  4010        simp. They may sometimes diverge as well or yield a different numbers
  4011        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4012        in case of problems. Sometimes subsequent calls to the classical
  4013        reasoner will fail because a preceeding call to the simplifier too
  4014        eagerly simplified the goal, e.g. deleted redundant premises.
  4015 
  4016   - The simplifier trace now shows the names of the applied rewrite rules
  4017 
  4018   - You can limit the number of recursive invocations of the simplifier
  4019     during conditional rewriting (where the simplifie tries to solve the
  4020     conditions before applying the rewrite rule):
  4021     ML "simp_depth_limit := n"
  4022     where n is an integer. Thus you can force termination where previously
  4023     the simplifier would diverge.
  4024 
  4025   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4026 
  4027   - No longer aborts on failed congruence proof.  Instead, the
  4028     congruence is ignored.
  4029 
  4030 * Pure: New generic framework for extracting programs from constructive
  4031   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4032   as HOL/Extraction for some case studies.
  4033 
  4034 * Pure: The main goal of the proof state is no longer shown by default, only
  4035 the subgoals. This behaviour is controlled by a new flag.
  4036    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4037 (ML: Proof.show_main_goal).
  4038 
  4039 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4040 rules whose conclusion matches subgoal 1:
  4041       PG menu: Isabelle/Isar -> Show me -> matching rules
  4042 The rules are ordered by how closely they match the subgoal.
  4043 In particular, rules that solve a subgoal outright are displayed first
  4044 (or rather last, the way they are printed).
  4045 (ML: ProofGeneral.print_intros())
  4046 
  4047 * Pure: New flag trace_unify_fail causes unification to print
  4048 diagnostic information (PG: in trace buffer) when it fails. This is
  4049 useful for figuring out why single step proofs like rule, erule or
  4050 assumption failed.
  4051 
  4052 * Pure: Locale specifications now produce predicate definitions
  4053 according to the body of text (covering assumptions modulo local
  4054 definitions); predicate "loc_axioms" covers newly introduced text,
  4055 while "loc" is cumulative wrt. all included locale expressions; the
  4056 latter view is presented only on export into the global theory
  4057 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4058 on the old view without predicates;
  4059 
  4060 * Pure: predefined locales "var" and "struct" are useful for sharing
  4061 parameters (as in CASL, for example); just specify something like
  4062 ``var x + var y + struct M'' as import;
  4063 
  4064 * Pure: improved thms_containing: proper indexing of facts instead of
  4065 raw theorems; check validity of results wrt. current name space;
  4066 include local facts of proof configuration (also covers active
  4067 locales), cover fixed variables in index; may use "_" in term
  4068 specification; an optional limit for the number of printed facts may
  4069 be given (the default is 40);
  4070 
  4071 * Pure: disallow duplicate fact bindings within new-style theory files
  4072 (batch-mode only);
  4073 
  4074 * Provers: improved induct method: assumptions introduced by case
  4075 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4076 the goal statement); "foo" still refers to all facts collectively;
  4077 
  4078 * Provers: the function blast.overloaded has been removed: all constants
  4079 are regarded as potentially overloaded, which improves robustness in exchange
  4080 for slight decrease in efficiency;
  4081 
  4082 * Provers/linorder: New generic prover for transitivity reasoning over
  4083 linear orders.  Note: this prover is not efficient!
  4084 
  4085 * Isar: preview of problems to finish 'show' now produce an error
  4086 rather than just a warning (in interactive mode);
  4087 
  4088 
  4089 *** HOL ***
  4090 
  4091 * arith(_tac)
  4092 
  4093  - Produces a counter example if it cannot prove a goal.
  4094    Note that the counter example may be spurious if the goal is not a formula
  4095    of quantifier-free linear arithmetic.
  4096    In ProofGeneral the counter example appears in the trace buffer.
  4097 
  4098  - Knows about div k and mod k where k is a numeral of type nat or int.
  4099 
  4100  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4101    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4102    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4103 
  4104 * simp's arithmetic capabilities have been enhanced a bit: it now
  4105 takes ~= in premises into account (by performing a case split);
  4106 
  4107 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4108 are distributed over a sum of terms;
  4109 
  4110 * New tactic "trans_tac" and method "trans" instantiate
  4111 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4112 "<=", "<" and "=").
  4113 
  4114 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4115 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4116 
  4117 * 'typedef' command has new option "open" to suppress the set
  4118 definition;
  4119 
  4120 * functions Min and Max on finite sets have been introduced (theory
  4121 Finite_Set);
  4122 
  4123 * attribute [symmetric] now works for relations as well; it turns
  4124 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4125 
  4126 * induct over a !!-quantified statement (say !!x1..xn):
  4127   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4128 
  4129 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4130 %x. None. Warning: empty_def now refers to the previously hidden definition
  4131 of the empty set.
  4132 
  4133 * Algebra: formalization of classical algebra.  Intended as base for
  4134 any algebraic development in Isabelle.  Currently covers group theory
  4135 (up to Sylow's theorem) and ring theory (Universal Property of
  4136 Univariate Polynomials).  Contributions welcome;
  4137 
  4138 * GroupTheory: deleted, since its material has been moved to Algebra;
  4139 
  4140 * Complex: new directory of the complex numbers with numeric constants,
  4141 nonstandard complex numbers, and some complex analysis, standard and
  4142 nonstandard (Jacques Fleuriot);
  4143 
  4144 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4145 
  4146 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4147 Fleuriot);
  4148 
  4149 * Real/HahnBanach: updated and adapted to locales;
  4150 
  4151 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4152 Gray and Kramer);
  4153 
  4154 * UNITY: added the Meier-Sanders theory of progress sets;
  4155 
  4156 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4157 as abstract algorithms, instantiated to the JVM;
  4158 
  4159 * Bali: Java source language formalization. Type system, operational
  4160 semantics, axiomatic semantics. Supported language features:
  4161 classes, interfaces, objects,virtual methods, static methods,
  4162 static/instance fields, arrays, access modifiers, definite
  4163 assignment, exceptions.
  4164 
  4165 
  4166 *** ZF ***
  4167 
  4168 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4169 universe, etc.);
  4170 
  4171 * Main ZF: virtually all theories converted to new-style format;
  4172 
  4173 
  4174 *** ML ***
  4175 
  4176 * Pure: Tactic.prove provides sane interface for internal proofs;
  4177 omits the infamous "standard" operation, so this is more appropriate
  4178 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4179 
  4180 * Pure: improved error reporting of simprocs;
  4181 
  4182 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4183 up simprocs;
  4184 
  4185 
  4186 *** Document preparation ***
  4187 
  4188 * uses \par instead of \\ for line breaks in theory text. This may
  4189 shift some page breaks in large documents. To get the old behaviour
  4190 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4191 
  4192 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4193 other packages
  4194 
  4195 * \<euro> now needs package babel/greek instead of marvosym (which
  4196 broke \Rightarrow)
  4197 
  4198 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4199 textcomp package)
  4200 
  4201 
  4202 
  4203 New in Isabelle2002 (March 2002)
  4204 --------------------------------
  4205 
  4206 *** Document preparation ***
  4207 
  4208 * greatly simplified document preparation setup, including more
  4209 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4210 instructive isatool mkdir; users should basically be able to get
  4211 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4212 users may run a separate document processing stage manually like this:
  4213 "isatool usedir -D output HOL Test && isatool document Test/output";
  4214 
  4215 * theory dependency graph may now be incorporated into documents;
  4216 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4217 with \includegraphics of LaTeX;
  4218 
  4219 * proper spacing of consecutive markup elements, especially text
  4220 blocks after section headings;
  4221 
  4222 * support bold style (for single symbols only), input syntax is like
  4223 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4224 
  4225 * \<bullet> is now output as bold \cdot by default, which looks much
  4226 better in printed text;
  4227 
  4228 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4229 note that these symbols are currently unavailable in Proof General /
  4230 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4231 
  4232 * isatool latex no longer depends on changed TEXINPUTS, instead
  4233 isatool document copies the Isabelle style files to the target
  4234 location;
  4235 
  4236 
  4237 *** Isar ***
  4238 
  4239 * Pure/Provers: improved proof by cases and induction;
  4240   - 'case' command admits impromptu naming of parameters (such as
  4241     "case (Suc n)");
  4242   - 'induct' method divinates rule instantiation from the inductive
  4243     claim; no longer requires excessive ?P bindings for proper
  4244     instantiation of cases;
  4245   - 'induct' method properly enumerates all possibilities of set/type
  4246     rules; as a consequence facts may be also passed through *type*
  4247     rules without further ado;
  4248   - 'induct' method now derives symbolic cases from the *rulified*
  4249     rule (before it used to rulify cases stemming from the internal
  4250     atomized version); this means that the context of a non-atomic
  4251     statement becomes is included in the hypothesis, avoiding the
  4252     slightly cumbersome show "PROP ?case" form;
  4253   - 'induct' may now use elim-style induction rules without chaining
  4254     facts, using ``missing'' premises from the goal state; this allows
  4255     rules stemming from inductive sets to be applied in unstructured
  4256     scripts, while still benefitting from proper handling of non-atomic
  4257     statements; NB: major inductive premises need to be put first, all
  4258     the rest of the goal is passed through the induction;
  4259   - 'induct' proper support for mutual induction involving non-atomic
  4260     rule statements (uses the new concept of simultaneous goals, see
  4261     below);
  4262   - append all possible rule selections, but only use the first
  4263     success (no backtracking);
  4264   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4265   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4266   - added 'print_induct_rules' (covered by help item in recent Proof
  4267     General versions);
  4268   - moved induct/cases attributes to Pure, methods to Provers;
  4269   - generic method setup instantiated for FOL and HOL;
  4270 
  4271 * Pure: support multiple simultaneous goal statements, for example
  4272 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4273 meta-level mechanism, this acts as if several individual goals had
  4274 been stated separately; in particular common proof methods need to be
  4275 repeated in order to cover all claims; note that a single elimination
  4276 step is *not* sufficient to establish the two conjunctions, so this
  4277 fails:
  4278 
  4279   assume "A & B" then have A and B ..   (*".." fails*)
  4280 
  4281 better use "obtain" in situations as above; alternative refer to
  4282 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4283 
  4284 * Pure: proper integration with ``locales''; unlike the original
  4285 version by Florian Kammller, Isar locales package high-level proof
  4286 contexts rather than raw logical ones (e.g. we admit to include
  4287 attributes everywhere); operations on locales include merge and
  4288 rename; support for implicit arguments (``structures''); simultaneous
  4289 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4290 some examples;
  4291 
  4292 * Pure: the following commands have been ``localized'', supporting a
  4293 target locale specification "(in name)": 'lemma', 'theorem',
  4294 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4295 stored both within the locale and at the theory level (exported and
  4296 qualified by the locale name);
  4297 
  4298 * Pure: theory goals may now be specified in ``long'' form, with
  4299 ad-hoc contexts consisting of arbitrary locale elements. for example
  4300 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4301 definitions may be given, too); the result is a meta-level rule with
  4302 the context elements being discharged in the obvious way;
  4303 
  4304 * Pure: new proof command 'using' allows to augment currently used
  4305 facts after a goal statement ('using' is syntactically analogous to
  4306 'apply', but acts on the goal's facts only); this allows chained facts
  4307 to be separated into parts given before and after a claim, as in
  4308 ``from a and b have C using d and e <proof>'';
  4309 
  4310 * Pure: renamed "antecedent" case to "rule_context";
  4311 
  4312 * Pure: new 'judgment' command records explicit information about the
  4313 object-logic embedding (used by several tools internally); no longer
  4314 use hard-wired "Trueprop";
  4315 
  4316 * Pure: added 'corollary' command;
  4317 
  4318 * Pure: fixed 'token_translation' command;
  4319 
  4320 * Pure: removed obsolete 'exported' attribute;
  4321 
  4322 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4323 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4324 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4325 
  4326 * Pure: method 'atomize' presents local goal premises as object-level
  4327 statements (atomic meta-level propositions); setup controlled via
  4328 rewrite rules declarations of 'atomize' attribute; example
  4329 application: 'induct' method with proper rule statements in improper
  4330 proof *scripts*;
  4331 
  4332 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4333 now consider the syntactic context of assumptions, giving a better
  4334 chance to get type-inference of the arguments right (this is
  4335 especially important for locales);
  4336 
  4337 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4338 mode;
  4339 
  4340 * Pure/obtain: the formal conclusion "thesis", being marked as
  4341 ``internal'', may no longer be reference directly in the text;
  4342 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4343 situations;
  4344 
  4345 * Pure: generic 'sym' attribute which declares a rule both as pure
  4346 'elim?' and for the 'symmetric' operation;
  4347 
  4348 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4349 text; the fixed correlation with particular command syntax has been
  4350 discontinued;
  4351 
  4352 * Pure: new method 'rules' is particularly well-suited for proof
  4353 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4354 but often produces more compact proof terms with less detours;
  4355 
  4356 * Pure/Provers/classical: simplified integration with pure rule
  4357 attributes and methods; the classical "intro?/elim?/dest?"
  4358 declarations coincide with the pure ones; the "rule" method no longer
  4359 includes classically swapped intros; "intro" and "elim" methods no
  4360 longer pick rules from the context; also got rid of ML declarations
  4361 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4362 INCOMPATIBILITY;
  4363 
  4364 * Provers/classical: attribute 'swapped' produces classical inversions
  4365 of introduction rules;
  4366 
  4367 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4368 rules instead of full simplifier context; 'iff' attribute handles
  4369 conditional rules;
  4370 
  4371 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4372 
  4373 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4374 "(permissive)" option to recover old behavior;
  4375 
  4376 * HOL: 'inductive' no longer features separate (collective) attributes
  4377 for 'intros' (was found too confusing);
  4378 
  4379 * HOL: properly declared induction rules less_induct and
  4380 wf_induct_rule;
  4381 
  4382 
  4383 *** HOL ***
  4384 
  4385 * HOL: moved over to sane numeral syntax; the new policy is as
  4386 follows:
  4387 
  4388   - 0 and 1 are polymorphic constants, which are defined on any
  4389   numeric type (nat, int, real etc.);
  4390 
  4391   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4392   binary representation internally;
  4393 
  4394   - type nat has special constructor Suc, and generally prefers Suc 0
  4395   over 1::nat and Suc (Suc 0) over 2::nat;
  4396 
  4397 This change may cause significant problems of INCOMPATIBILITY; here
  4398 are some hints on converting existing sources:
  4399 
  4400   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4401   entities, so expressions involving "-" (unary or binary minus) need
  4402   to be spaced properly;
  4403 
  4404   - existing occurrences of "1" may need to be constraint "1::nat" or
  4405   even replaced by Suc 0; similar for old "2";
  4406 
  4407   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4408 
  4409   - remove all special provisions on numerals in proofs;
  4410 
  4411 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4412 representation (depends on bin_arith_simps in the default context);
  4413 
  4414 * HOL: symbolic syntax for x^2 (numeral 2);
  4415 
  4416 * HOL: the class of all HOL types is now called "type" rather than
  4417 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4418 in axclass/classes, instance/arities, and (usually rare) occurrences
  4419 in typings (of consts etc.); internally the class is called
  4420 "HOL.type", ML programs should refer to HOLogic.typeS;
  4421 
  4422 * HOL/record package improvements:
  4423   - new derived operations "fields" to build a partial record section,
  4424     "extend" to promote a fixed record to a record scheme, and
  4425     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4426     declared as simp by default;
  4427   - shared operations ("more", "fields", etc.) now need to be always
  4428     qualified) --- potential INCOMPATIBILITY;
  4429   - removed "make_scheme" operations (use "make" with "extend") --
  4430     INCOMPATIBILITY;
  4431   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4432   - provides cases/induct rules for use with corresponding Isar
  4433     methods (for concrete records, record schemes, concrete more
  4434     parts, and schematic more parts -- in that order);
  4435   - internal definitions directly based on a light-weight abstract
  4436     theory of product types over typedef rather than datatype;
  4437 
  4438 * HOL: generic code generator for generating executable ML code from
  4439 specifications; specific support for HOL constructs such as inductive
  4440 datatypes and sets, as well as recursive functions; can be invoked
  4441 via 'generate_code' theory section;
  4442 
  4443 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4444 
  4445 * HOL: consolidated and renamed several theories.  In particular:
  4446         Ord.thy has been absorbed into HOL.thy
  4447         String.thy has been absorbed into List.thy
  4448 
  4449 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4450 (beware of argument permutation!);
  4451 
  4452 * HOL: linorder_less_split superseded by linorder_cases;
  4453 
  4454 * HOL/List: "nodups" renamed to "distinct";
  4455 
  4456 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4457 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4458   - Ex_def has changed, now need to use some_eq_ex
  4459 
  4460 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4461 in this (rare) case use:
  4462 
  4463   delSWrapper "split_all_tac"
  4464   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4465 
  4466 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4467 MAY FAIL;
  4468 
  4469 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4470 Isabelle's type classes, ^ on functions and relations has too general
  4471 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4472 necessary to attach explicit type constraints;
  4473 
  4474 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4475 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4476 renamed accordingly (eg "compI" -> "rel_compI").
  4477 
  4478 * HOL: syntax translations now work properly with numerals and records
  4479 expressions;
  4480 
  4481 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4482 of "lam" -- INCOMPATIBILITY;
  4483 
  4484 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4485 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4486 renamed "Product_Type.unit";
  4487 
  4488 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4489 
  4490 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4491 the "cases" method);
  4492 
  4493 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4494 Florian Kammller);
  4495 
  4496 * HOL/IMP: updated and converted to new-style theory format; several
  4497 parts turned into readable document, with proper Isar proof texts and
  4498 some explanations (by Gerwin Klein);
  4499 
  4500 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4501 
  4502 * HOL-Hyperreal is now a logic image;
  4503 
  4504 
  4505 *** HOLCF ***
  4506 
  4507 * Isar: consts/constdefs supports mixfix syntax for continuous
  4508 operations;
  4509 
  4510 * Isar: domain package adapted to new-style theory format, e.g. see
  4511 HOLCF/ex/Dnat.thy;
  4512 
  4513 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4514 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4515 lift.induct_tac, always use UU instead of Undef;
  4516 
  4517 * HOLCF/IMP: updated and converted to new-style theory;
  4518 
  4519 
  4520 *** ZF ***
  4521 
  4522 * Isar: proper integration of logic-specific tools and packages,
  4523 including theory commands '(co)inductive', '(co)datatype',
  4524 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4525 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4526 
  4527 * theory Main no longer includes AC; for the Axiom of Choice, base
  4528 your theory on Main_ZFC;
  4529 
  4530 * the integer library now covers quotients and remainders, with many
  4531 laws relating division to addition, multiplication, etc.;
  4532 
  4533 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4534 typeless version of the formalism;
  4535 
  4536 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4537 format;
  4538 
  4539 * ZF/Induct: new directory for examples of inductive definitions,
  4540 including theory Multiset for multiset orderings; converted to
  4541 new-style theory format;
  4542 
  4543 * ZF: many new theorems about lists, ordinals, etc.;
  4544 
  4545 
  4546 *** General ***
  4547 
  4548 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4549 variable proof controls level of detail: 0 = no proofs (only oracle
  4550 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4551 also ref manual for further ML interfaces;
  4552 
  4553 * Pure/axclass: removed obsolete ML interface
  4554 goal_subclass/goal_arity;
  4555 
  4556 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4557 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4558 separate tokens, so expressions involving minus need to be spaced
  4559 properly;
  4560 
  4561 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4562 rather than "infixl" or "infixr";
  4563 
  4564 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4565 sort constraint specifications in type inference; e.g. "x::_::foo"
  4566 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4567 type variable);
  4568 
  4569 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4570 control output of nested => (types); the default behavior is
  4571 "type_brackets";
  4572 
  4573 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4574 tokens into AST constants;
  4575 
  4576 * Pure/syntax: prefer later declarations of translations and print
  4577 translation functions; potential INCOMPATIBILITY: need to reverse
  4578 multiple declarations for same syntax element constant;
  4579 
  4580 * Pure/show_hyps reset by default (in accordance to existing Isar
  4581 practice);
  4582 
  4583 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4584 addSafter;
  4585 
  4586 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4587 as well;
  4588 
  4589 * system: tested support for MacOS X; should be able to get Isabelle +
  4590 Proof General to work in a plain Terminal after installing Poly/ML
  4591 (e.g. from the Isabelle distribution area) and GNU bash alone
  4592 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4593 support requires further installations, e.g. from
  4594 http://fink.sourceforge.net/);
  4595 
  4596 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4597 
  4598 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4599 of 40 MB), cf. ML_OPTIONS;
  4600 
  4601 * system: Proof General keywords specification is now part of the
  4602 Isabelle distribution (see etc/isar-keywords.el);
  4603 
  4604 * system: support for persistent Proof General sessions (refrain from
  4605 outdating all loaded theories on startup); user may create writable
  4606 logic images like this: ``isabelle -q HOL Test'';
  4607 
  4608 * system: smart selection of Isabelle process versus Isabelle
  4609 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4610 run both "isabelle" and "Isabelle" even if file names are badly
  4611 damaged (executable inspects the case of the first letter of its own
  4612 name); added separate "isabelle-process" and "isabelle-interface";
  4613 
  4614 * system: refrain from any attempt at filtering input streams; no
  4615 longer support ``8bit'' encoding of old isabelle font, instead proper
  4616 iso-latin characters may now be used; the related isatools
  4617 "symbolinput" and "nonascii" have disappeared as well;
  4618 
  4619 * system: removed old "xterm" interface (the print modes "xterm" and
  4620 "xterm_color" are still available for direct use in a suitable
  4621 terminal);
  4622 
  4623 
  4624 
  4625 New in Isabelle99-2 (February 2001)
  4626 -----------------------------------
  4627 
  4628 *** Overview of INCOMPATIBILITIES ***
  4629 
  4630 * HOL: please note that theories in the Library and elsewhere often use the
  4631 new-style (Isar) format; to refer to their theorems in an ML script you must
  4632 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4633 
  4634 * HOL: inductive package no longer splits induction rule aggressively,
  4635 but only as far as specified by the introductions given; the old
  4636 format may be recovered via ML function complete_split_rule or attribute
  4637 'split_rule (complete)';
  4638 
  4639 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4640 gfp_Tarski to gfp_unfold;
  4641 
  4642 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4643 
  4644 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4645 relation); infix "^^" has been renamed "``"; infix "``" has been
  4646 renamed "`"; "univalent" has been renamed "single_valued";
  4647 
  4648 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4649 operation;
  4650 
  4651 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4652 
  4653 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4654 
  4655 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4656 consequence, it is no longer monotonic wrt. the local goal context
  4657 (which is now passed through the inductive cases);
  4658 
  4659 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4660 \<gg> to \<ggreater>;
  4661 
  4662 
  4663 *** Document preparation ***
  4664 
  4665 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4666 available: are "it" for near math-mode best-style output, "sl" for
  4667 slanted text style, and "tt" for plain type-writer; if no
  4668 \isabellestyle command is given, output is according to slanted
  4669 type-writer);
  4670 
  4671 * support sub/super scripts (for single symbols only), input syntax is
  4672 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4673 
  4674 * some more standard symbols; see Appendix A of the system manual for
  4675 the complete list of symbols defined in isabellesym.sty;
  4676 
  4677 * improved isabelle style files; more abstract symbol implementation
  4678 (should now use \isamath{...} and \isatext{...} in custom symbol
  4679 definitions);
  4680 
  4681 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4682 state; Note that presentation of goal states does not conform to
  4683 actual human-readable proof documents.  Please do not include goal
  4684 states into document output unless you really know what you are doing!
  4685 
  4686 * proper indentation of antiquoted output with proportional LaTeX
  4687 fonts;
  4688 
  4689 * no_document ML operator temporarily disables LaTeX document
  4690 generation;
  4691 
  4692 * isatool unsymbolize tunes sources for plain ASCII communication;
  4693 
  4694 
  4695 *** Isar ***
  4696 
  4697 * Pure: Isar now suffers initial goal statements to contain unbound
  4698 schematic variables (this does not conform to actual readable proof
  4699 documents, due to unpredictable outcome and non-compositional proof
  4700 checking); users who know what they are doing may use schematic goals
  4701 for Prolog-style synthesis of proven results;
  4702 
  4703 * Pure: assumption method (an implicit finishing) now handles actual
  4704 rules as well;
  4705 
  4706 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4707 initial goal, declare "that" only as Pure intro (only for single
  4708 steps); the "that" rule assumption may now be involved in implicit
  4709 finishing, thus ".." becomes a feasible for trivial obtains;
  4710 
  4711 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4712 instance proofs may be performed by "..";
  4713 
  4714 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4715 statements as well;
  4716 
  4717 * Pure: more robust selection of calculational rules;
  4718 
  4719 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4720 rule (as well as the assumption rule);
  4721 
  4722 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4723 lemmas, using the graph browser tool;
  4724 
  4725 * Pure: predict failure of "show" in interactive mode;
  4726 
  4727 * Pure: 'thms_containing' now takes actual terms as arguments;
  4728 
  4729 * HOL: improved method 'induct' --- now handles non-atomic goals
  4730 (potential INCOMPATIBILITY); tuned error handling;
  4731 
  4732 * HOL: cases and induct rules now provide explicit hints about the
  4733 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4734 any remaining facts are inserted into the goal verbatim;
  4735 
  4736 * HOL: local contexts (aka cases) may now contain term bindings as
  4737 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4738 the result to be shown in each case;
  4739 
  4740 * HOL: added 'recdef_tc' command;
  4741 
  4742 * isatool convert assists in eliminating legacy ML scripts;
  4743 
  4744 
  4745 *** HOL ***
  4746 
  4747 * HOL/Library: a collection of generic theories to be used together
  4748 with main HOL; the theory loader path already includes this directory
  4749 by default; the following existing theories have been moved here:
  4750 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4751 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4752 
  4753 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4754 modelling and verification task performed in Isabelle/HOL +
  4755 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4756 
  4757 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4758 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4759 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4760 'domain', this makes the theory consistent with mathematical
  4761 literature;
  4762 
  4763 * HOL basics: added overloaded operations "inverse" and "divide"
  4764 (infix "/"), syntax for generic "abs" operation, generic summation
  4765 operator \<Sum>;
  4766 
  4767 * HOL/typedef: simplified package, provide more useful rules (see also
  4768 HOL/subset.thy);
  4769 
  4770 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4771 now expressed as a proper nested rule (old-style tactic scripts may
  4772 require atomize_strip_tac to cope with non-atomic premises);
  4773 
  4774 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4775 to "split_conv" (old name still available for compatibility);
  4776 
  4777 * HOL: improved concrete syntax for strings (e.g. allows translation
  4778 rules with string literals);
  4779 
  4780 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4781  and Fleuriot's mechanization of analysis, including the transcendental
  4782  functions for the reals;
  4783 
  4784 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4785 
  4786 
  4787 *** CTT ***
  4788 
  4789 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4790 "lam" is displayed as TWO lambda-symbols
  4791 
  4792 * CTT: theory Main now available, containing everything (that is, Bool
  4793 and Arith);
  4794 
  4795 
  4796 *** General ***
  4797 
  4798 * Pure: the Simplifier has been implemented properly as a derived rule
  4799 outside of the actual kernel (at last!); the overall performance
  4800 penalty in practical applications is about 50%, while reliability of
  4801 the Isabelle inference kernel has been greatly improved;
  4802 
  4803 * print modes "brackets" and "no_brackets" control output of nested =>
  4804 (types) and ==> (props); the default behaviour is "brackets";
  4805 
  4806 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4807 as assumptions as well;
  4808 
  4809 * system: support Poly/ML 4.0;
  4810 
  4811 * system: isatool install handles KDE version 1 or 2;
  4812 
  4813 
  4814 
  4815 New in Isabelle99-1 (October 2000)
  4816 ----------------------------------
  4817 
  4818 *** Overview of INCOMPATIBILITIES ***
  4819 
  4820 * HOL: simplification of natural numbers is much changed; to partly
  4821 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4822 issue the following ML commands:
  4823 
  4824   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4825   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4826 
  4827 * HOL: simplification no longer dives into case-expressions; this is
  4828 controlled by "t.weak_case_cong" for each datatype t;
  4829 
  4830 * HOL: nat_less_induct renamed to less_induct;
  4831 
  4832 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4833 fixsome to patch .thy and .ML sources automatically;
  4834 
  4835   select_equality  -> some_equality
  4836   select_eq_Ex     -> some_eq_ex
  4837   selectI2EX       -> someI2_ex
  4838   selectI2         -> someI2
  4839   selectI          -> someI
  4840   select1_equality -> some1_equality
  4841   Eps_sym_eq       -> some_sym_eq_trivial
  4842   Eps_eq           -> some_eq_trivial
  4843 
  4844 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4845 
  4846 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4847 instead);
  4848 
  4849 * HOL: the recursion equations generated by 'recdef' are now called
  4850 f.simps instead of f.rules;
  4851 
  4852 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4853 
  4854 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4855 sometimes be needed;
  4856 
  4857 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4858 
  4859 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4860 
  4861 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4862 product is now "<*>" instead of "Times"; the lexicographic product is
  4863 now "<*lex*>" instead of "**";
  4864 
  4865 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4866 of main HOL, but was unused); better use HOL's datatype package;
  4867 
  4868 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4869 the old syntax may be recovered as follows:
  4870 
  4871   syntax (symbols)
  4872     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4873       (infixl "\\<oplus>" 100)
  4874 
  4875 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4876 
  4877 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4878 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4879 internally;
  4880 
  4881 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4882 changed from A/r to A//r;
  4883 
  4884 * ZF: new treatment of arithmetic (nat & int) may break some old
  4885 proofs;
  4886 
  4887 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4888 rulify -> rule_format, elimify -> elim_format, ...);
  4889 
  4890 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4891 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4892 should have to change intro!! to intro? only); replaced "delrule" by
  4893 "rule del";
  4894 
  4895 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4896 
  4897 * Provers: strengthened force_tac by using new first_best_tac;
  4898 
  4899 * LaTeX document preparation: several changes of isabelle.sty (see
  4900 lib/texinputs);
  4901 
  4902 
  4903 *** Document preparation ***
  4904 
  4905 * formal comments (text blocks etc.) in new-style theories may now
  4906 contain antiquotations of thm/prop/term/typ/text to be presented
  4907 according to latex print mode; concrete syntax is like this:
  4908 @{term[show_types] "f(x) = a + x"};
  4909 
  4910 * isatool mkdir provides easy setup of Isabelle session directories,
  4911 including proper document sources;
  4912 
  4913 * generated LaTeX sources are now deleted after successful run
  4914 (isatool document -c); may retain a copy somewhere else via -D option
  4915 of isatool usedir;
  4916 
  4917 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4918 style files, achieving self-contained LaTeX sources and simplifying
  4919 LaTeX debugging;
  4920 
  4921 * old-style theories now produce (crude) LaTeX output as well;
  4922 
  4923 * browser info session directories are now self-contained (may be put
  4924 on WWW server seperately); improved graphs of nested sessions; removed
  4925 graph for 'all sessions';
  4926 
  4927 * several improvements in isabelle style files; \isabellestyle{it}
  4928 produces fake math mode output; \isamarkupheader is now \section by
  4929 default; see lib/texinputs/isabelle.sty etc.;
  4930 
  4931 
  4932 *** Isar ***
  4933 
  4934 * Isar/Pure: local results and corresponding term bindings are now
  4935 subject to Hindley-Milner polymorphism (similar to ML); this
  4936 accommodates incremental type-inference very nicely;
  4937 
  4938 * Isar/Pure: new derived language element 'obtain' supports
  4939 generalized existence reasoning;
  4940 
  4941 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4942 support accumulation of results, without applying any rules yet;
  4943 useful to collect intermediate results without explicit name
  4944 references, and for use with transitivity rules with more than 2
  4945 premises;
  4946 
  4947 * Isar/Pure: scalable support for case-analysis type proofs: new
  4948 'case' language element refers to local contexts symbolically, as
  4949 produced by certain proof methods; internally, case names are attached
  4950 to theorems as "tags";
  4951 
  4952 * Isar/Pure: theory command 'hide' removes declarations from
  4953 class/type/const name spaces;
  4954 
  4955 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4956 indicate potential overloading;
  4957 
  4958 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4959 
  4960 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4961 "{a,b,c}" instead of {a,b,c};
  4962 
  4963 * Isar/Pure now provides its own version of intro/elim/dest
  4964 attributes; useful for building new logics, but beware of confusion
  4965 with the version in Provers/classical;
  4966 
  4967 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4968 case name 'antecedent';
  4969 
  4970 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4971 to the current context is now done automatically);
  4972 
  4973 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4974 for definining proof methods in ML;
  4975 
  4976 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4977 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4978 most cases, one should have to change intro!! to intro? only);
  4979 replaced "delrule" by "rule del";
  4980 
  4981 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4982 'symmetric' attribute (the latter supercedes [RS sym]);
  4983 
  4984 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4985 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4986 well (including splits);
  4987 
  4988 * Isar/Provers: Simplifier and Classical methods now support all kind
  4989 of modifiers used in the past, including 'cong', 'iff', etc.
  4990 
  4991 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4992 of Simplifier and Classical reasoner);
  4993 
  4994 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4995 now support named cases; major packages (inductive, datatype, primrec,
  4996 recdef) support case names and properly name parameters;
  4997 
  4998 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4999 monotonicity conditions are extracted to be proven at end of
  5000 calculations;
  5001 
  5002 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5003 method anyway;
  5004 
  5005 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5006 split_if split_if_asm; datatype package provides theorems foo.splits =
  5007 foo.split foo.split_asm for each datatype;
  5008 
  5009 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5010 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5011 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5012 use "(cases (simplified))" method in proper proof texts);
  5013 
  5014 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5015 
  5016 * Isar: names of theorems etc. may be natural numbers as well;
  5017 
  5018 * Isar: 'pr' command: optional arguments for goals_limit and
  5019 ProofContext.prems_limit; no longer prints theory contexts, but only
  5020 proof states;
  5021 
  5022 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5023 additional print modes to be specified; e.g. "pr(latex)" will print
  5024 proof state according to the Isabelle LaTeX style;
  5025 
  5026 * Isar: improved support for emulating tactic scripts, including proof
  5027 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5028 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5029 (for HOL datatypes);
  5030 
  5031 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5032 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5033 'proof method scripts' have to be in depth-first order;
  5034 
  5035 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5036 
  5037 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5038 should instead use individual commands for printing items
  5039 (print_commands, print_methods etc.);
  5040 
  5041 * Isar: added 'nothing' --- the empty list of theorems;
  5042 
  5043 
  5044 *** HOL ***
  5045 
  5046 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5047 corresponding virtual machine and a specification of its bytecode
  5048 verifier and a lightweight bytecode verifier, including proofs of
  5049 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5050 Cornelia Pusch (see also the homepage of project Bali at
  5051 http://isabelle.in.tum.de/Bali/);
  5052 
  5053 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5054 Clemens Ballarin;
  5055 
  5056 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5057 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5058 Rasmussen;
  5059 
  5060 * HOL/Lattice: fundamental concepts of lattice theory and order
  5061 structures, including duals, properties of bounds versus algebraic
  5062 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5063 Theorem for complete lattices etc.; may also serve as a demonstration
  5064 for abstract algebraic reasoning using axiomatic type classes, and
  5065 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5066 
  5067 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5068 von Oheimb;
  5069 
  5070 * HOL/IMPP: extension of IMP with local variables and mutually
  5071 recursive procedures, by David von Oheimb;
  5072 
  5073 * HOL/Lambda: converted into new-style theory and document;
  5074 
  5075 * HOL/ex/Multiquote: example of multiple nested quotations and
  5076 anti-quotations -- basically a generalized version of de-Bruijn
  5077 representation; very useful in avoiding lifting of operations;
  5078 
  5079 * HOL/record: added general record equality rule to simpset; fixed
  5080 select-update simplification procedure to handle extended records as
  5081 well; admit "r" as field name;
  5082 
  5083 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5084 other numeric types and also as the identity of groups, rings, etc.;
  5085 
  5086 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5087 Types nat and int belong to this axclass;
  5088 
  5089 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5090    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5091    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5092   two terms #m*u and #n*u are replaced by #(m+n)*u
  5093     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5094   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5095     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5096 
  5097 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5098 powerful prover for predicate logic but knows nothing of clasets; see
  5099 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5100 
  5101 * HOL: new version of "case_tac" subsumes both boolean case split and
  5102 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5103 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5104 
  5105 * HOL: simplification no longer dives into case-expressions: only the
  5106 selector expression is simplified, but not the remaining arms; to
  5107 enable full simplification of case-expressions for datatype t, you may
  5108 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5109 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5110 
  5111 * HOL/recdef: the recursion equations generated by 'recdef' for
  5112 function 'f' are now called f.simps instead of f.rules; if all
  5113 termination conditions are proved automatically, these simplification
  5114 rules are added to the simpset, as in primrec; rules may be named
  5115 individually as well, resulting in a separate list of theorems for
  5116 each equation;
  5117 
  5118 * HOL/While is a new theory that provides a while-combinator. It
  5119 permits the definition of tail-recursive functions without the
  5120 provision of a termination measure. The latter is necessary once the
  5121 invariant proof rule for while is applied.
  5122 
  5123 * HOL: new (overloaded) notation for the set of elements below/above
  5124 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5125 
  5126 * HOL: theorems impI, allI, ballI bound as "strip";
  5127 
  5128 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5129 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5130 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5131 
  5132 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5133 
  5134 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5135 main HOL, but was unused);
  5136 
  5137 * HOL: fewer consts declared as global (e.g. have to refer to
  5138 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5139 
  5140 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5141 in case of overlap with user translations (e.g. judgements over
  5142 tuples); (note that the underlying logical represenation is still
  5143 bogus);
  5144 
  5145 
  5146 *** ZF ***
  5147 
  5148 * ZF: simplification automatically cancels common terms in arithmetic
  5149 expressions over nat and int;
  5150 
  5151 * ZF: new treatment of nat to minimize type-checking: all operators
  5152 coerce their operands to a natural number using the function natify,
  5153 making the algebraic laws unconditional;
  5154 
  5155 * ZF: as above, for int: operators coerce their operands to an integer
  5156 using the function intify;
  5157 
  5158 * ZF: the integer library now contains many of the usual laws for the
  5159 orderings, including $<=, and monotonicity laws for $+ and $*;
  5160 
  5161 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5162 simplification;
  5163 
  5164 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5165 to the simplifier and classical reasoner simultaneously;
  5166 
  5167 
  5168 *** General ***
  5169 
  5170 * Provers: blast_tac now handles actual object-logic rules as
  5171 assumptions; note that auto_tac uses blast_tac internally as well;
  5172 
  5173 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5174 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5175 
  5176 * Provers: delrules now handles destruct rules as well (no longer need
  5177 explicit make_elim);
  5178 
  5179 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5180   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5181 use instead the strong form,
  5182   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5183 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5184 from destruct-rules;
  5185 
  5186 * Provers: Simplifier.easy_setup provides a fast path to basic
  5187 Simplifier setup for new object-logics;
  5188 
  5189 * Pure: AST translation rules no longer require constant head on LHS;
  5190 
  5191 * Pure: improved name spaces: ambiguous output is qualified; support
  5192 for hiding of names;
  5193 
  5194 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5195 XSYMBOL_HOME; no longer need to do manual configuration in most
  5196 situations;
  5197 
  5198 * system: compression of ML heaps images may now be controlled via -c
  5199 option of isabelle and isatool usedir (currently only observed by
  5200 Poly/ML);
  5201 
  5202 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5203 useful for remote X11);
  5204 
  5205 * system: provide TAGS file for Isabelle sources;
  5206 
  5207 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5208 order;
  5209 
  5210 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5211 timing flag supersedes proof_timing and Toplevel.trace;
  5212 
  5213 * ML: new combinators |>> and |>>> for incremental transformations
  5214 with secondary results (e.g. certain theory extensions):
  5215 
  5216 * ML: PureThy.add_defs gets additional argument to indicate potential
  5217 overloading (usually false);
  5218 
  5219 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5220 results;
  5221 
  5222 
  5223 
  5224 New in Isabelle99 (October 1999)
  5225 --------------------------------
  5226 
  5227 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5228 
  5229 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5230 are no longer simplified.  (This allows the simplifier to unfold recursive
  5231 functional programs.)  To restore the old behaviour, declare
  5232 
  5233     Delcongs [if_weak_cong];
  5234 
  5235 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5236 complement;
  5237 
  5238 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5239 
  5240 * HOL/datatype: mutual_induct_tac no longer exists --
  5241   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5242 
  5243 * HOL/typedef: fixed type inference for representing set; type
  5244 arguments now have to occur explicitly on the rhs as type constraints;
  5245 
  5246 * ZF: The con_defs part of an inductive definition may no longer refer
  5247 to constants declared in the same theory;
  5248 
  5249 * HOL, ZF: the function mk_cases, generated by the inductive
  5250 definition package, has lost an argument.  To simplify its result, it
  5251 uses the default simpset instead of a supplied list of theorems.
  5252 
  5253 * HOL/List: the constructors of type list are now Nil and Cons;
  5254 
  5255 * Simplifier: the type of the infix ML functions
  5256         setSSolver addSSolver setSolver addSolver
  5257 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5258 for packaging solvers. A solver is created via
  5259         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5260 where the string argument is only a comment.
  5261 
  5262 
  5263 *** Proof tools ***
  5264 
  5265 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5266 decision procedure for linear arithmetic. Currently it is used for
  5267 types `nat', `int', and `real' in HOL (see below); it can, should and
  5268 will be instantiated for other types and logics as well.
  5269 
  5270 * The simplifier now accepts rewrite rules with flexible heads, eg
  5271      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5272   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5273   matching.
  5274 
  5275 
  5276 *** General ***
  5277 
  5278 * New Isabelle/Isar subsystem provides an alternative to traditional
  5279 tactical theorem proving; together with the ProofGeneral/isar user
  5280 interface it offers an interactive environment for developing human
  5281 readable proof documents (Isar == Intelligible semi-automated
  5282 reasoning); for further information see isatool doc isar-ref,
  5283 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5284 
  5285 * improved and simplified presentation of theories: better HTML markup
  5286 (including colors), graph views in several sizes; isatool usedir now
  5287 provides a proper interface for user theories (via -P option); actual
  5288 document preparation based on (PDF)LaTeX is available as well (for
  5289 new-style theories only); see isatool doc system for more information;
  5290 
  5291 * native support for Proof General, both for classic Isabelle and
  5292 Isabelle/Isar;
  5293 
  5294 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5295 using the graph browser tool;
  5296 
  5297 * Isabelle manuals now also available as PDF;
  5298 
  5299 * theory loader rewritten from scratch (may not be fully
  5300 bug-compatible); old loadpath variable has been replaced by show_path,
  5301 add_path, del_path, reset_path functions; new operations such as
  5302 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5303 isatool doc ref);
  5304 
  5305 * improved isatool install: option -k creates KDE application icon,
  5306 option -p DIR installs standalone binaries;
  5307 
  5308 * added ML_PLATFORM setting (useful for cross-platform installations);
  5309 more robust handling of platform specific ML images for SML/NJ;
  5310 
  5311 * the settings environment is now statically scoped, i.e. it is never
  5312 created again in sub-processes invoked from isabelle, isatool, or
  5313 Isabelle;
  5314 
  5315 * path element specification '~~' refers to '$ISABELLE_HOME';
  5316 
  5317 * in locales, the "assumes" and "defines" parts may be omitted if
  5318 empty;
  5319 
  5320 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5321 long arrows);
  5322 
  5323 * new print_mode "HTML";
  5324 
  5325 * new flag show_tags controls display of tags of theorems (which are
  5326 basically just comments that may be attached by some tools);
  5327 
  5328 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5329 mode and goal output format:
  5330 
  5331 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5332 244c244
  5333 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5334 ---
  5335 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5336 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5337 181c181
  5338 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5339 ---
  5340 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5341 
  5342 * function bind_thms stores lists of theorems (cf. bind_thm);
  5343 
  5344 * new shorthand tactics ftac, eatac, datac, fatac;
  5345 
  5346 * qed (and friends) now accept "" as result name; in that case the
  5347 theorem is not stored, but proper checks and presentation of the
  5348 result still apply;
  5349 
  5350 * theorem database now also indexes constants "Trueprop", "all",
  5351 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5352 
  5353 
  5354 *** HOL ***
  5355 
  5356 ** HOL arithmetic **
  5357 
  5358 * There are now decision procedures for linear arithmetic over nat and
  5359 int:
  5360 
  5361 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5362 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5363 are treated as atomic; subformulae not involving type `nat' or `int'
  5364 are ignored; quantified subformulae are ignored unless they are
  5365 positive universal or negative existential. The tactic has to be
  5366 invoked by hand and can be a little bit slow. In particular, the
  5367 running time is exponential in the number of occurrences of `min' and
  5368 `max', and `-' on `nat'.
  5369 
  5370 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5371 (negated) (in)equalities among the premises and the conclusion into
  5372 account (i.e. no compound formulae) and does not know about `min' and
  5373 `max', and `-' on `nat'. It is fast and is used automatically by the
  5374 simplifier.
  5375 
  5376 NB: At the moment, these decision procedures do not cope with mixed
  5377 nat/int formulae where the two parts interact, such as `m < n ==>
  5378 int(m) < int(n)'.
  5379 
  5380 * HOL/Numeral provides a generic theory of numerals (encoded
  5381 efficiently as bit strings); setup for types nat/int/real is in place;
  5382 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5383 int, existing theories and proof scripts may require a few additional
  5384 type constraints;
  5385 
  5386 * integer division and remainder can now be performed on constant
  5387 arguments;
  5388 
  5389 * many properties of integer multiplication, division and remainder
  5390 are now available;
  5391 
  5392 * An interface to the Stanford Validity Checker (SVC) is available through the
  5393 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5394 are proved automatically.  SVC must be installed separately, and its results
  5395 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5396 invocation of the underlying oracle).  For SVC see
  5397   http://verify.stanford.edu/SVC
  5398 
  5399 * IsaMakefile: the HOL-Real target now builds an actual image;
  5400 
  5401 
  5402 ** HOL misc **
  5403 
  5404 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5405 (in Isabelle/Isar) -- by Gertrud Bauer;
  5406 
  5407 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5408 analysis for assembly languages with subtypes;
  5409 
  5410 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5411 -- avoids syntactic ambiguities and treats state, transition, and
  5412 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5413 changed syntax and (many) tactics;
  5414 
  5415 * HOL/inductive: Now also handles more general introduction rules such
  5416   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5417   theorems are now maintained within the theory (maintained via the
  5418   "mono" attribute);
  5419 
  5420 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5421   (using function types) such as
  5422 
  5423   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5424 
  5425 * HOL/record: record_simproc (part of the default simpset) takes care
  5426 of selectors applied to updated records; record_split_tac is no longer
  5427 part of the default claset; update_defs may now be removed from the
  5428 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5429 
  5430   claset_ref () := claset() addSWrapper record_split_wrapper;
  5431   Delsimprocs [record_simproc]
  5432 
  5433 * HOL/typedef: fixed type inference for representing set; type
  5434 arguments now have to occur explicitly on the rhs as type constraints;
  5435 
  5436 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5437 names rather than an ML expression;
  5438 
  5439 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5440 supplied later.  Program schemes can be defined, such as
  5441     "While B C s = (if B s then While B C (C s) else s)"
  5442 where the well-founded relation can be chosen after B and C have been given.
  5443 
  5444 * HOL/List: the constructors of type list are now Nil and Cons;
  5445 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5446 course, ML tools referring to List.list.op # etc. have to be adapted;
  5447 
  5448 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5449 disabled by default; run isabelle with option -m HOL to get back to
  5450 the original Gordon/HOL-style output;
  5451 
  5452 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5453 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5454 
  5455 * HOL basic syntax simplified (more orthogonal): all variants of
  5456 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5457 Eps operator is provided as well: "SOME x. P[x]";
  5458 
  5459 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5460 
  5461 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5462 thus available for user theories;
  5463 
  5464 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5465 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5466 time;
  5467 
  5468 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5469 several times and then mp;
  5470 
  5471 
  5472 *** LK ***
  5473 
  5474 * the notation <<...>> is now available as a notation for sequences of
  5475 formulas;
  5476 
  5477 * the simplifier is now installed
  5478 
  5479 * the axiom system has been generalized (thanks to Soren Heilmann)
  5480 
  5481 * the classical reasoner now has a default rule database
  5482 
  5483 
  5484 *** ZF ***
  5485 
  5486 * new primrec section allows primitive recursive functions to be given
  5487 directly (as in HOL) over datatypes and the natural numbers;
  5488 
  5489 * new tactics induct_tac and exhaust_tac for induction (or case
  5490 analysis) over datatypes and the natural numbers;
  5491 
  5492 * the datatype declaration of type T now defines the recursor T_rec;
  5493 
  5494 * simplification automatically does freeness reasoning for datatype
  5495 constructors;
  5496 
  5497 * automatic type-inference, with AddTCs command to insert new
  5498 type-checking rules;
  5499 
  5500 * datatype introduction rules are now added as Safe Introduction rules
  5501 to the claset;
  5502 
  5503 * the syntax "if P then x else y" is now available in addition to
  5504 if(P,x,y);
  5505 
  5506 
  5507 *** Internal programming interfaces ***
  5508 
  5509 * tuned simplifier trace output; new flag debug_simp;
  5510 
  5511 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5512 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5513 
  5514 * AxClass.axclass_tac lost the theory argument;
  5515 
  5516 * tuned current_goals_markers semantics: begin / end goal avoids
  5517 printing empty lines;
  5518 
  5519 * removed prs and prs_fn hook, which was broken because it did not
  5520 include \n in its semantics, forcing writeln to add one
  5521 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5522 string -> unit if you really want to output text without newline;
  5523 
  5524 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5525 plain output, interface builders may have to enable 'isabelle_font'
  5526 mode to get Isabelle font glyphs as before;
  5527 
  5528 * refined token_translation interface; INCOMPATIBILITY: output length
  5529 now of type real instead of int;
  5530 
  5531 * theory loader actions may be traced via new ThyInfo.add_hook
  5532 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5533 your own database of information attached to *whole* theories -- as
  5534 opposed to intra-theory data slots offered via TheoryDataFun;
  5535 
  5536 * proper handling of dangling sort hypotheses (at last!);
  5537 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5538 extra sort hypotheses that can be witnessed from the type signature;
  5539 the force_strip_shyps flag is gone, any remaining shyps are simply
  5540 left in the theorem (with a warning issued by strip_shyps_warning);
  5541 
  5542 
  5543 
  5544 New in Isabelle98-1 (October 1998)
  5545 ----------------------------------
  5546 
  5547 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5548 
  5549 * several changes of automated proof tools;
  5550 
  5551 * HOL: major changes to the inductive and datatype packages, including
  5552 some minor incompatibilities of theory syntax;
  5553 
  5554 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5555 called `inj_on';
  5556 
  5557 * HOL: removed duplicate thms in Arith:
  5558   less_imp_add_less  should be replaced by  trans_less_add1
  5559   le_imp_add_le      should be replaced by  trans_le_add1
  5560 
  5561 * HOL: unary minus is now overloaded (new type constraints may be
  5562 required);
  5563 
  5564 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5565 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5566 now taken as an integer constant.
  5567 
  5568 * Pure: ML function 'theory_of' renamed to 'theory';
  5569 
  5570 
  5571 *** Proof tools ***
  5572 
  5573 * Simplifier:
  5574   1. Asm_full_simp_tac is now more aggressive.
  5575      1. It will sometimes reorient premises if that increases their power to
  5576         simplify.
  5577      2. It does no longer proceed strictly from left to right but may also
  5578         rotate premises to achieve further simplification.
  5579      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5580      old Asm_full_simp_tac in that it does not rotate premises.
  5581   2. The simplifier now knows a little bit about nat-arithmetic.
  5582 
  5583 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5584 allows for selected deletion of wrappers, by introduction of names for
  5585 wrapper functionals.  This implies that addbefore, addSbefore,
  5586 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5587 and that adding two tactics with the same name overwrites the first
  5588 one (emitting a warning).
  5589   type wrapper = (int -> tactic) -> (int -> tactic)
  5590   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5591   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5592   delWrapper, delSWrapper: claset *  string            -> claset
  5593   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5594 
  5595 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5596 semantics; addbefore now affects only the unsafe part of step_tac
  5597 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5598 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5599 by Force_tac;
  5600 
  5601 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5602 compWrapper; added safe wrapper (and access functions for it);
  5603 
  5604 * HOL/split_all_tac is now much faster and fails if there is nothing
  5605 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5606 and the names of the automatically generated variables have changed.
  5607 split_all_tac has moved within claset() from unsafe wrappers to safe
  5608 wrappers, which means that !!-bound variables are split much more
  5609 aggressively, and safe_tac and clarify_tac now split such variables.
  5610 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5611 Note: the same holds for record_split_tac, which does the job of
  5612 split_all_tac for record fields.
  5613 
  5614 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5615 permanently to the default simpset using Addsplits just like
  5616 Addsimps. They can be removed via Delsplits just like
  5617 Delsimps. Lower-case versions are also available.
  5618 
  5619 * HOL/Simplifier: The rule split_if is now part of the default
  5620 simpset. This means that the simplifier will eliminate all occurrences
  5621 of if-then-else in the conclusion of a goal. To prevent this, you can
  5622 either remove split_if completely from the default simpset by
  5623 `Delsplits [split_if]' or remove it in a specific call of the
  5624 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5625 other case splitting rules to/from the default simpset: every datatype
  5626 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5627 t is the name of the datatype).
  5628 
  5629 * Classical reasoner / Simplifier combination: new force_tac (and
  5630 derivatives Force_tac, force) combines rewriting and classical
  5631 reasoning (and whatever other tools) similarly to auto_tac, but is
  5632 aimed to solve the given subgoal completely.
  5633 
  5634 
  5635 *** General ***
  5636 
  5637 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5638 and `goalw': the theory is no longer needed as an explicit argument -
  5639 the current theory context is used; assumptions are no longer returned
  5640 at the ML-level unless one of them starts with ==> or !!; it is
  5641 recommended to convert to these new commands using isatool fixgoal
  5642 (backup your sources first!);
  5643 
  5644 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5645 the current theory context, and 'theory' to lookup stored theories;
  5646 
  5647 * new theory section 'locale' for declaring constants, assumptions and
  5648 definitions that have local scope;
  5649 
  5650 * new theory section 'nonterminals' for purely syntactic types;
  5651 
  5652 * new theory section 'setup' for generic ML setup functions
  5653 (e.g. package initialization);
  5654 
  5655 * the distribution now includes Isabelle icons: see
  5656 lib/logo/isabelle-{small,tiny}.xpm;
  5657 
  5658 * isatool install - install binaries with absolute references to
  5659 ISABELLE_HOME/bin;
  5660 
  5661 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5662 
  5663 * print mode 'emacs' reserved for Isamode;
  5664 
  5665 * support multiple print (ast) translations per constant name;
  5666 
  5667 * theorems involving oracles are now printed with a suffixed [!];
  5668 
  5669 
  5670 *** HOL ***
  5671 
  5672 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5673 
  5674 * HOL/inductive package reorganized and improved: now supports mutual
  5675 definitions such as
  5676 
  5677   inductive EVEN ODD
  5678     intrs
  5679       null "0 : EVEN"
  5680       oddI "n : EVEN ==> Suc n : ODD"
  5681       evenI "n : ODD ==> Suc n : EVEN"
  5682 
  5683 new theorem list "elims" contains an elimination rule for each of the
  5684 recursive sets; inductive definitions now handle disjunctive premises
  5685 correctly (also ZF);
  5686 
  5687 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5688 "mutual_induct" no longer exists - the induction rule is always
  5689 contained in "induct";
  5690 
  5691 
  5692 * HOL/datatype package re-implemented and greatly improved: now
  5693 supports mutually recursive datatypes such as
  5694 
  5695   datatype
  5696     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5697             | SUM ('a aexp) ('a aexp)
  5698             | DIFF ('a aexp) ('a aexp)
  5699             | NUM 'a
  5700   and
  5701     'a bexp = LESS ('a aexp) ('a aexp)
  5702             | AND ('a bexp) ('a bexp)
  5703             | OR ('a bexp) ('a bexp)
  5704 
  5705 as well as indirectly recursive datatypes such as
  5706 
  5707   datatype
  5708     ('a, 'b) term = Var 'a
  5709                   | App 'b ((('a, 'b) term) list)
  5710 
  5711 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5712 induction on mutually / indirectly recursive datatypes.
  5713 
  5714 Primrec equations are now stored in theory and can be accessed via
  5715 <function_name>.simps.
  5716 
  5717 INCOMPATIBILITIES:
  5718 
  5719   - Theories using datatypes must now have theory Datatype as an
  5720     ancestor.
  5721   - The specific <typename>.induct_tac no longer exists - use the
  5722     generic induct_tac instead.
  5723   - natE has been renamed to nat.exhaust - use exhaust_tac
  5724     instead of res_inst_tac ... natE. Note that the variable
  5725     names in nat.exhaust differ from the names in natE, this
  5726     may cause some "fragile" proofs to fail.
  5727   - The theorems split_<typename>_case and split_<typename>_case_asm
  5728     have been renamed to <typename>.split and <typename>.split_asm.
  5729   - Since default sorts of type variables are now handled correctly,
  5730     some datatype definitions may have to be annotated with explicit
  5731     sort constraints.
  5732   - Primrec definitions no longer require function name and type
  5733     of recursive argument.
  5734 
  5735 Consider using isatool fixdatatype to adapt your theories and proof
  5736 scripts to the new package (backup your sources first!).
  5737 
  5738 
  5739 * HOL/record package: considerably improved implementation; now
  5740 includes concrete syntax for record types, terms, updates; theorems
  5741 for surjective pairing and splitting !!-bound record variables; proof
  5742 support is as follows:
  5743 
  5744   1) standard conversions (selectors or updates applied to record
  5745 constructor terms) are part of the standard simpset;
  5746 
  5747   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5748 made part of standard simpset and claset via addIffs;
  5749 
  5750   3) a tactic for record field splitting (record_split_tac) is part of
  5751 the standard claset (addSWrapper);
  5752 
  5753 To get a better idea about these rules you may retrieve them via
  5754 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5755 the name of your record type.
  5756 
  5757 The split tactic 3) conceptually simplifies by the following rule:
  5758 
  5759   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5760 
  5761 Thus any record variable that is bound by meta-all will automatically
  5762 blow up into some record constructor term, consequently the
  5763 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5764 solve record problems automatically.
  5765 
  5766 
  5767 * reorganized the main HOL image: HOL/Integ and String loaded by
  5768 default; theory Main includes everything;
  5769 
  5770 * automatic simplification of integer sums and comparisons, using cancellation;
  5771 
  5772 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5773 
  5774 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5775 
  5776 * many new identities for unions, intersections, set difference, etc.;
  5777 
  5778 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5779 called split_if, split_split, split_sum_case and split_nat_case (to go
  5780 with add/delsplits);
  5781 
  5782 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5783 (?x::unit) = (); this is made part of the default simpset, which COULD
  5784 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5785 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5786 unit_abs_eta_conv is added in order to counter the effect of
  5787 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5788 %u.f();
  5789 
  5790 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5791 makes more sense);
  5792 
  5793 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5794   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5795   disjointness reasoning but breaking a few old proofs.
  5796 
  5797 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5798 to 'converse' from 'inverse' (for compatibility with ZF and some
  5799 literature);
  5800 
  5801 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5802 the well-founded relation;
  5803 
  5804 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5805     Compl A.  The "Compl" syntax remains available as input syntax for this
  5806     release ONLY.
  5807 
  5808 * HOL/Update: new theory of function updates:
  5809     f(a:=b) == %x. if x=a then b else f x
  5810 may also be iterated as in f(a:=b,c:=d,...);
  5811 
  5812 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5813 
  5814 * HOL/List:
  5815   - new function list_update written xs[i:=v] that updates the i-th
  5816     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5817   - new function `upt' written [i..j(] which generates the list
  5818     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5819     bound write [i..j], which is a shorthand for [i..j+1(].
  5820   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5821 
  5822 * HOL/Arith:
  5823   - removed 'pred' (predecessor) function;
  5824   - generalized some theorems about n-1;
  5825   - many new laws about "div" and "mod";
  5826   - new laws about greatest common divisors (see theory ex/Primes);
  5827 
  5828 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5829 instead of "inverse";
  5830 
  5831 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5832   of the multiset ordering;
  5833 
  5834 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5835   (not included by default);
  5836 
  5837 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5838 
  5839 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5840   programs, i.e. different program variables may have different types.
  5841 
  5842 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5843   [previously, this check worked only if the rewrite rule was unconditional]
  5844   Now rew can involve either definitions or equalities (either == or =).
  5845 
  5846 
  5847 *** ZF ***
  5848 
  5849 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5850   only the theorems proved on ZF.ML;
  5851 
  5852 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5853   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5854   disjointness reasoning but breaking a few old proofs.
  5855 
  5856 * ZF/Update: new theory of function updates
  5857     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5858   may also be iterated as in f(a:=b,c:=d,...);
  5859 
  5860 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5861 
  5862 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5863   [previously, this check worked only if the rewrite rule was unconditional]
  5864   Now rew can involve either definitions or equalities (either == or =).
  5865 
  5866 * case_tac provided for compatibility with HOL
  5867     (like the old excluded_middle_tac, but with subgoals swapped)
  5868 
  5869 
  5870 *** Internal programming interfaces ***
  5871 
  5872 * Pure: several new basic modules made available for general use, see
  5873 also src/Pure/README;
  5874 
  5875 * improved the theory data mechanism to support encapsulation (data
  5876 kind name replaced by private Object.kind, acting as authorization
  5877 key); new type-safe user interface via functor TheoryDataFun; generic
  5878 print_data function becomes basically useless;
  5879 
  5880 * removed global_names compatibility flag -- all theory declarations
  5881 are qualified by default;
  5882 
  5883 * module Pure/Syntax now offers quote / antiquote translation
  5884 functions (useful for Hoare logic etc. with implicit dependencies);
  5885 see HOL/ex/Antiquote for an example use;
  5886 
  5887 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5888 cterm -> thm;
  5889 
  5890 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5891 subgoal;
  5892 
  5893 * Display.print_goals function moved to Locale.print_goals;
  5894 
  5895 * standard print function for goals supports current_goals_markers
  5896 variable for marking begin of proof, end of proof, start of goal; the
  5897 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5898 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5899 for example;
  5900 
  5901 
  5902 
  5903 New in Isabelle98 (January 1998)
  5904 --------------------------------
  5905 
  5906 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5907 
  5908 * changed lexical syntax of terms / types: dots made part of long
  5909 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5910 
  5911 * simpset (and claset) reference variable replaced by functions
  5912 simpset / simpset_ref;
  5913 
  5914 * no longer supports theory aliases (via merge) and non-trivial
  5915 implicit merge of thms' signatures;
  5916 
  5917 * most internal names of constants changed due to qualified names;
  5918 
  5919 * changed Pure/Sequence interface (see Pure/seq.ML);
  5920 
  5921 
  5922 *** General Changes ***
  5923 
  5924 * hierachically structured name spaces (for consts, types, axms, thms
  5925 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5926 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5927 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5928 long_names for fully qualified output names; NOTE: ML programs
  5929 (special tactics, packages etc.) referring to internal names may have
  5930 to be adapted to cope with fully qualified names; in case of severe
  5931 backward campatibility problems try setting 'global_names' at compile
  5932 time to have enrything declared within a flat name space; one may also
  5933 fine tune name declarations in theories via the 'global' and 'local'
  5934 section;
  5935 
  5936 * reimplemented the implicit simpset and claset using the new anytype
  5937 data filed in signatures; references simpset:simpset ref etc. are
  5938 replaced by functions simpset:unit->simpset and
  5939 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5940 to patch your ML files accordingly;
  5941 
  5942 * HTML output now includes theory graph data for display with Java
  5943 applet or isatool browser; data generated automatically via isatool
  5944 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5945 
  5946 * defs may now be conditional; improved rewrite_goals_tac to handle
  5947 conditional equations;
  5948 
  5949 * defs now admits additional type arguments, using TYPE('a) syntax;
  5950 
  5951 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5952 creates a new theory node; implicit merge of thms' signatures is
  5953 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5954 transfer:theory->thm->thm in (rare) cases;
  5955 
  5956 * improved handling of draft signatures / theories; draft thms (and
  5957 ctyps, cterms) are automatically promoted to real ones;
  5958 
  5959 * slightly changed interfaces for oracles: admit many per theory, named
  5960 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5961 
  5962 * print_goals: optional output of const types (set show_consts and
  5963 show_types);
  5964 
  5965 * improved output of warnings (###) and errors (***);
  5966 
  5967 * subgoal_tac displays a warning if the new subgoal has type variables;
  5968 
  5969 * removed old README and Makefiles;
  5970 
  5971 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5972 
  5973 * removed obsolete init_pps and init_database;
  5974 
  5975 * deleted the obsolete tactical STATE, which was declared by
  5976     fun STATE tacfun st = tacfun st st;
  5977 
  5978 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5979 (which abbreviates $HOME);
  5980 
  5981 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5982 use isatool fixseq to adapt your ML programs (this works for fully
  5983 qualified references to the Sequence structure only!);
  5984 
  5985 * use_thy no longer requires writable current directory; it always
  5986 reloads .ML *and* .thy file, if either one is out of date;
  5987 
  5988 
  5989 *** Classical Reasoner ***
  5990 
  5991 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5992 tactics that use classical reasoning to simplify a subgoal without
  5993 splitting it into several subgoals;
  5994 
  5995 * Safe_tac: like safe_tac but uses the default claset;
  5996 
  5997 
  5998 *** Simplifier ***
  5999 
  6000 * added simplification meta rules:
  6001     (asm_)(full_)simplify: simpset -> thm -> thm;
  6002 
  6003 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6004 logics (again);
  6005 
  6006 * added prems argument to simplification procedures;
  6007 
  6008 * HOL, FOL, ZF: added infix function `addsplits':
  6009   instead of `<simpset> setloop (split_tac <thms>)'
  6010   you can simply write `<simpset> addsplits <thms>'
  6011 
  6012 
  6013 *** Syntax ***
  6014 
  6015 * TYPE('a) syntax for type reflection terms;
  6016 
  6017 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6018 
  6019 * pretty printer: changed order of mixfix annotation preference (again!);
  6020 
  6021 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6022 
  6023 
  6024 *** HOL ***
  6025 
  6026 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6027   with `addloop' of the simplifier to faciliate case splitting in premises.
  6028 
  6029 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6030 
  6031 * HOL/Auth: new protocol proofs including some for the Internet
  6032   protocol TLS;
  6033 
  6034 * HOL/Map: new theory of `maps' a la VDM;
  6035 
  6036 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6037 cancelling out common nat summands from =, <, <= (in)equalities, or
  6038 differences; simplification procedures nat_cancel_factor for
  6039 cancelling common factor from =, <, <= (in)equalities over natural
  6040 sums; nat_cancel contains both kinds of procedures, it is installed by
  6041 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6042 
  6043 * HOL/simplifier: terms of the form
  6044   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6045   are rewritten to
  6046   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6047   and those of the form
  6048   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6049   are rewritten to
  6050   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6051 
  6052 * HOL/datatype
  6053   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6054 
  6055   P(t_case f1 ... fn x) =
  6056      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6057         ...
  6058        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6059      )
  6060 
  6061   and a theorem `split_t_case_asm' of the form
  6062 
  6063   P(t_case f1 ... fn x) =
  6064     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6065         ...
  6066        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6067      )
  6068   which can be added to a simpset via `addsplits'. The existing theorems
  6069   expand_list_case and expand_option_case have been renamed to
  6070   split_list_case and split_option_case.
  6071 
  6072 * HOL/Arithmetic:
  6073   - `pred n' is automatically converted to `n-1'.
  6074     Users are strongly encouraged not to use `pred' any longer,
  6075     because it will disappear altogether at some point.
  6076   - Users are strongly encouraged to write "0 < n" rather than
  6077     "n ~= 0". Theorems and proof tools have been modified towards this
  6078     `standard'.
  6079 
  6080 * HOL/Lists:
  6081   the function "set_of_list" has been renamed "set" (and its theorems too);
  6082   the function "nth" now takes its arguments in the reverse order and
  6083   has acquired the infix notation "!" as in "xs!n".
  6084 
  6085 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6086 
  6087 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6088   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6089 
  6090 * HOL/record: extensible records with schematic structural subtyping
  6091 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6092 still lacks various theorems and concrete record syntax;
  6093 
  6094 
  6095 *** HOLCF ***
  6096 
  6097 * removed "axioms" and "generated by" sections;
  6098 
  6099 * replaced "ops" section by extended "consts" section, which is capable of
  6100   handling the continuous function space "->" directly;
  6101 
  6102 * domain package:
  6103   . proves theorems immediately and stores them in the theory,
  6104   . creates hierachical name space,
  6105   . now uses normal mixfix annotations (instead of cinfix...),
  6106   . minor changes to some names and values (for consistency),
  6107   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6108   . separator between mutual domain defs: changed "," to "and",
  6109   . improved handling of sort constraints;  now they have to
  6110     appear on the left-hand side of the equations only;
  6111 
  6112 * fixed LAM <x,y,zs>.b syntax;
  6113 
  6114 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6115 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6116 
  6117 
  6118 *** FOL and ZF ***
  6119 
  6120 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6121   with `addloop' of the simplifier to faciliate case splitting in premises.
  6122 
  6123 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6124 in HOL, they strip ALL and --> from proved theorems;
  6125 
  6126 
  6127 
  6128 New in Isabelle94-8 (May 1997)
  6129 ------------------------------
  6130 
  6131 *** General Changes ***
  6132 
  6133 * new utilities to build / run / maintain Isabelle etc. (in parts
  6134 still somewhat experimental); old Makefiles etc. still functional;
  6135 
  6136 * new 'Isabelle System Manual';
  6137 
  6138 * INSTALL text, together with ./configure and ./build scripts;
  6139 
  6140 * reimplemented type inference for greater efficiency, better error
  6141 messages and clean internal interface;
  6142 
  6143 * prlim command for dealing with lots of subgoals (an easier way of
  6144 setting goals_limit);
  6145 
  6146 
  6147 *** Syntax ***
  6148 
  6149 * supports alternative (named) syntax tables (parser and pretty
  6150 printer); internal interface is provided by add_modesyntax(_i);
  6151 
  6152 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6153 be used in conjunction with the Isabelle symbol font; uses the
  6154 "symbols" syntax table;
  6155 
  6156 * added token_translation interface (may translate name tokens in
  6157 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6158 the current print_mode); IMPORTANT: user print translation functions
  6159 are responsible for marking newly introduced bounds
  6160 (Syntax.mark_boundT);
  6161 
  6162 * token translations for modes "xterm" and "xterm_color" that display
  6163 names in bold, underline etc. or colors (which requires a color
  6164 version of xterm);
  6165 
  6166 * infixes may now be declared with names independent of their syntax;
  6167 
  6168 * added typed_print_translation (like print_translation, but may
  6169 access type of constant);
  6170 
  6171 
  6172 *** Classical Reasoner ***
  6173 
  6174 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6175 some limitations.  Blast_tac...
  6176   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6177   + ignores elimination rules that don't have the correct format
  6178         (the conclusion MUST be a formula variable)
  6179   + ignores types, which can make HOL proofs fail
  6180   + rules must not require higher-order unification, e.g. apply_type in ZF
  6181     [message "Function Var's argument not a bound variable" relates to this]
  6182   + its proof strategy is more general but can actually be slower
  6183 
  6184 * substitution with equality assumptions no longer permutes other
  6185 assumptions;
  6186 
  6187 * minor changes in semantics of addafter (now called addaltern); renamed
  6188 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6189 (and access functions for it);
  6190 
  6191 * improved combination of classical reasoner and simplifier:
  6192   + functions for handling clasimpsets
  6193   + improvement of addss: now the simplifier is called _after_ the
  6194     safe steps.
  6195   + safe variant of addss called addSss: uses safe simplifications
  6196     _during_ the safe steps. It is more complete as it allows multiple
  6197     instantiations of unknowns (e.g. with slow_tac).
  6198 
  6199 *** Simplifier ***
  6200 
  6201 * added interface for simplification procedures (functions that
  6202 produce *proven* rewrite rules on the fly, depending on current
  6203 redex);
  6204 
  6205 * ordering on terms as parameter (used for ordered rewriting);
  6206 
  6207 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6208 
  6209 * the solver is now split into a safe and an unsafe part.
  6210 This should be invisible for the normal user, except that the
  6211 functions setsolver and addsolver have been renamed to setSolver and
  6212 addSolver; added safe_asm_full_simp_tac;
  6213 
  6214 
  6215 *** HOL ***
  6216 
  6217 * a generic induction tactic `induct_tac' which works for all datatypes and
  6218 also for type `nat';
  6219 
  6220 * a generic case distinction tactic `exhaust_tac' which works for all
  6221 datatypes and also for type `nat';
  6222 
  6223 * each datatype comes with a function `size';
  6224 
  6225 * patterns in case expressions allow tuple patterns as arguments to
  6226 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6227 
  6228 * primrec now also works with type nat;
  6229 
  6230 * recdef: a new declaration form, allows general recursive functions to be
  6231 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6232 
  6233 * the constant for negation has been renamed from "not" to "Not" to
  6234 harmonize with FOL, ZF, LK, etc.;
  6235 
  6236 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6237 infinite lists;
  6238 
  6239 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6240 
  6241 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6242 problems in commutative rings, using axiomatic type classes for + and *;
  6243 
  6244 * more examples in HOL/MiniML and HOL/Auth;
  6245 
  6246 * more default rewrite rules for quantifiers, union/intersection;
  6247 
  6248 * a new constant `arbitrary == @x.False';
  6249 
  6250 * HOLCF/IOA replaces old HOL/IOA;
  6251 
  6252 * HOLCF changes: derived all rules and arities
  6253   + axiomatic type classes instead of classes
  6254   + typedef instead of faking type definitions
  6255   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6256   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6257   + eliminated the types void, one, tr
  6258   + use un